Method of cleaning distribution of tray in reactor system with fluidised bed

FIELD: process engineering.

SUBSTANCE: invention relates to cleaning of distribution tray in polymerisation reactor system with fluidised bed. One of proposed versions comprises: first mode wherein cleaning is performed at approximately normal base magnitude of reduced rate of gas in polymerisation reactor system with fluidised bed. Said system comprises reactor vessel, circulation circuit and distribution tray arranged in said vessel nearby its inlet. In second mode, gas reduced rate is increased to magnitudes exceeding said base magnitude in aforesaid first mode to the level sufficient for increasing circulating gas temperature at inlet to temperatures higher than circulating gas mean temperature at inlet in aforesaid first mode and to the level sufficient for displacement of dirt from distribution tray holes.

EFFECT: reduced or eliminated clogging of distribution tray without switching off of the system.

34 cl, 5 ex, 9 dwg

Cross-reference to related applications

In this application of the claimed advantages of document No. 61/194 071, filed September 24, 2008, the disclosure of which is fully incorporated into the present description by reference.

The technical field to which the present invention

The present invention relates to methods aimed at cleaning up the distribution plates polymerization reactor, more specifically, reactor systems fluidized bed.

Background of invention

In gas-phase method for obtaining polyolefins, such as polyethylene, gaseous Allenby monomer (e.g. ethylene, propylene, etc.), hydrogen, comonomer and other raw materials are transformed into a solid polyolefin product. In General, gas-phase reactors include a reactor with a fluidized bed, the compressor and the cooler. The reaction of the support in two-phase fluidized bed, comprising the granular polyethylene and gaseous reagents, using a fluidizing gas which is passed through the distribution plate located near the bottom of the reaction vessel. The reaction vessel, usually made of carbon steel and designed for operation at pressures up to about 30 bar (or about 3.0 MPa). In fluidized bed spray the catalyst. The heat of reaction is AI away with the flow of circulating gas. This gas stream is compressed and cooled in an external recirculation loop, and then re-injected into the lower part of the reactor, in which the specified gas passes through the distribution plate. To maintain the desired concentrations of reagents add make-up flows of raw materials.

The work of most reactor systems critically depends on good mixing in the fluidized bed to ensure uniform conditions in the reactor, remove the heat and the efficiency of the catalyst. Good mixing is required to ensure good distribution of the catalyst layer to ensure homogeneity of the reaction rate and the final formation of warmth, thus, it is possible to minimize the probability of occurrence of local temperature deviations (or "hot spots") in the layer.

The process must be controllable and capable of providing high performance. In General, the higher the operating temperature, the greater the opportunity to achieve high performance. However, as it approaches the operating temperature to the melting point of polyolefin product, the polyolefin particles become sticky. This can lead to the emergence of cohesion or adhesion in the fluidized bed (in General). If the temperature exceeds certain limits (depending on the melting point of teaching is adequate in the process of polymer), the degree of stickiness in the fluidized bed may become excessive, leading to poor liquefaction and mixing. In some cases, the presence of sticky polymer and, as a consequence, insufficient mixing can lead to localized deviations in the temperature of sufficient magnitude to form agglomerates of particles (or clusters) spravivshegosya polymer in the reactor. In other cases, sticky polymer and poor mixing can contribute to the formation of polymer plates on the inner walls of the reactor.

Poor mixing in the fluidized bed (and, consequently, increased the risk of clots or plates) can also be caused by contamination of the distribution plate. Pollution distribution plate represents one of the main causes of downtime commercial polymerization reactor systems fluidized bed. The blockage is usually caused by settling of the polymer resin in numerous small holes of the distribution plate, this leads to a reduction of the fluid flow through the plate or full blockage. As indicated above, for uniform temperature control requires good mixing in the fluidized bed. As partial or complete clogging of the holes of the distribution plate, the capacity of the recirculating gas, the post is speaking out in a fluidized bed, to remove heat from the reacting materials is reduced. Moreover, hot spots can form in areas of reduced flow velocity of the fluid in the fluidized bed (specifically in the areas directly above partially or fully blocked holes). The result of these processes is the formation of sticky clots of polymer inside the fluidized bed and/or education of the plates along the walls of the vessel and other parts of the reactor system. These clots or plate, eventually, will fall on the distribution plate of the reactor, which further violates liquefaction, gas circulation and discharge of product from the reactor. The result will be forced to stop the reactor to clean the system. The formation of clots or plates, thus, may be a significant "opportunity, leading to the stop"that affect commercial reactor systems. To reduce to a minimum the possibility of clots or plates it is important to prevent or minimize clogging of the distribution plate.

Recently watched a particularly problematic form of clogging plates (called corsacorta)that may occur during startup of the reactor.

Although the exact cause of this phenomenon is not yet fully understood, with the introduction of catalyst layer in the region of the actor enjoyed a high static charge ash (measured in the flow of recirculating gas). The origin of this charge is associated with the entrainment of catalyst particles from the fluidized bed and the subsequent acquisition of the triboelectric charge of the catalyst particles in frictional contact with the walls of the recirculation system. Charged particles of the catalyst can be drawn static forces of attraction to the walls of the reactor, where they can accumulate (especially under the plate and/or the upper part of the reactor) and to stick with the formation of clogging. This mechanism is confirmed by the fact that the observed temperature peaks (greater than the operating temperature of the reactor) in the lower arch reactor (under distribution plate).

Conventional wisdom is that low speed recirculating flow (and corresponding low reduced gas velocity in the fluidized bed) reduce clogging of the distribution plate by minimizing entrainment of solids recirculating flow, thus reducing to a minimum the contacting of such solid substances from distributing.

Existing methods to eliminate the clogging of the distribution plates require shutdown of the reactor and the physical removal of the clogging of the holes, for example, by means of a drill. Such stop is not only costly in relation to production losses, but the nor endanger the employee, located and operated within the reactor system.

Accordingly, it would be desirable to reduce and/or eliminate clogging of the distribution plate without requiring a system shutdown.

Summary of the invention

The way to clean switch plates in a polymerization reactor system with a fluidized bed in accordance with one of the preferred options includes in the first mode, the implementation of work at about normal basic value of a given gas velocity in a polymerization reactor system, fluidized bed, including the reactor vessel, the recirculation circuit and a distribution plate located in the reactor vessel near its inlet. In the second mode shows the velocity of the gas is increased to values greater than the base value of the first mode, to a level sufficient to raise the temperature of recirculating gas in the inlet hole to the values greater than the average temperature of the recirculating gas in the inlet port in the first mode, and to a level sufficient to displace clogging of the holes of the distribution plate.

The way to clean switch plates in a polymerization reactor system with a fluidized bed in accordance with another preferred VK is uchet tracking clogging switch plates, located in the fluidized bed polymerization reactor system with a fluidized bed, comprising a reactor vessel, the recirculation circuit and a distribution plate located in the reactor vessel near its inlet; determining the need to reduce clogging of the distribution plate; and, if the determination indicates that the pollution distribution plate is desirable or necessary to reduce the increase in the rate of recirculating gas flowing through the recirculation loop to a level sufficient to displace and, preferably, completely remove the clogging of the holes of the distribution plate.

The method of obtaining the polymer in a polymerization reactor system with a fluidized bed in accordance with another preferred option involves running a polymerization reactor system with a fluidized bed, comprising a reactor vessel, the recirculation circuit and a distribution plate located in the reactor vessel near its inlet; and after reaching the condensing mode of operation, the increase in the rate of recirculating gas flowing through the recirculation loop to a level sufficient to displace and, preferably, completely remove the clogging of the holes of the distribution plate.

Brief description of drawings

Figure 1 represents a scheme of the General methods, systems and/or equipment in accordance with certain preferred variants of the present invention, illustrating implementation of the present invention in a gas-phase polymerization reactor system.

Figure 2 represents a scheme of the General methods, systems and/or equipment in accordance with certain preferred variants of the present invention, illustrating implementation of the present invention in a gas-phase polymerization reactor system.

Figure 3 is a diagram of the General methods, systems and/or equipment in accordance with certain preferred variants of the present invention, illustrating implementation of the present invention in a gas-phase polymerization reactor system.

Figure 4 is a diagram of the General methods, systems and/or equipment in accordance with certain preferred variants of the present invention, illustrating implementation of the present invention in gazopa the Noah polymerization reactor system.

Figure 5 is a diagram of the General methods, systems and/or equipment in accordance with certain preferred variants of the present invention, illustrating implementation of the present invention in a gas-phase polymerization reactor system.

6 is a graph illustrating a typical profile clogging plates depending on time after reaching the condensation mode at time 0 days to process gas-phase polymerization of polyethylene fluidized bed without the use of processing additives.

7 is a graph illustrating the profile of the clogging of the plates depending on the time after reaching the condensation mode at time 0 days to process gas-phase polymerization of polyethylene in a fluidized bed without the use of processing additives.

Fig is a graph illustrating the profile of the clogging of the plates depending on the time after reaching the condensation mode at time 0 days to process gas-phase polymerization of polyethylene in a fluidized bed with the use of processing AIDS in increased speed recirculating gas.

Fig.9 is a graph illustrating the profile of the clogging of the plates depending on the time on the Les achievements of the condensation mode at time 0 days to process gas-phase polymerization of polyethylene in a fluidized bed without the use of processing AIDS in high speed recirculating gas.

Detailed description of the invention

The following description is intended to illustrate the basic principles of the present invention and is not intended to restrict the ideas of the invention specified in the claims. In addition, specific features described in the present description, can be used in conjunction with other described features in each of the possible combinations and transformations.

It should also be noted that the use in the present description and appended claims, the singular number includes references to the plural, unless otherwise indicated.

The authors of the present invention unexpectedly discovered a way to clean switch plates polymerization reactor with a fluidized bed, for example, a commercial reactor UNIPOL™, in the course of its work, eliminating the need to stop the reactor system to clean switch plates. In one of the approaches in this methodology is applied to the high speed circulating gas to push and, preferably, removal of the contaminant (clogging) of some of the holes of the distribution plate.

This discovery directly contrary to generally accepted opinion, whereby to prevent entrainment of product and catalyst recycle gas requires what I use reduced speeds recirculating gas for minimizing clogging of the distribution plate and the heat exchanger (which is also in this description referred to as a chiller).

The main method in accordance with one of the preferred variants of the present invention can be described, for example, with reference to figure 1, in which the circulating gas passes through a polymerization reactor system 100 fluidized bed, comprising a reactor vessel 110, the recirculation circuit 122 and the distribution plate 128 that is located in the reactor vessel 110 near the inlet 126 of the reactor vessel 110. In the first mode, the circulating gas is moving at the first speed (the base value of a given gas velocity) through the polymerization reactor system 100 fluidized bed. In the second mode shows the velocity of the gas increases to values larger than the base value of the first mode to a level sufficient to raise the temperature of the circulating gas in the inlet port 126 to values larger than the average temperature of the circulating gas inlet 126 of the first mode, and to a level sufficient to displace and, preferably, removal of a certain amount of pollutants out of the holes of the distribution plate 128.

It should be noted that in this and other preferred embodiments, the increase in the speed of the circulating gas to a level sufficient to displace and, preferably, removal of a certain amount of polluting substances is tion of the holes of the distribution plate, does not necessarily mean that the contaminant is immediately removed from the holes. It also does not mean that the removal of the obstruction is only circulating gas. Rather, as will be clear hereinafter, before you remove appreciable quantities of pollutants may take several hours or days. Moreover, without wishing to be bound by any theory, believe that the removal of the obstruction contributes to the totality of conditions, including high speed, as described below.

In more General preferred approach the main method, with reference to figure 1, track the amount of contaminants in the distribution plate 128 in a polymerization reactor system 100 fluidized bed. A polymerization reactor system 100 fluidized bed, preferably, includes a reactor vessel 110, the recirculation circuit 122 and the distribution plate 128 that is located in the reactor vessel 110 near the inlet 126 of the reactor vessel. The determination is carried out in connection with the need to reduce the amount of contaminants in the distribution plate 128. If the determination indicates the desirability or the need to reduce the amount of contaminants in the distribution plate 128, the speed of the circulating gas passing through recirculation the circuit, increase to a level sufficient to displace and, preferably, removal of the contaminant from the holes of the distribution plate.

In accordance with another basic preferred approach of the General method, with reference to figure 1, the polymerization reactor system 100 fluidized bed run. A polymerization reactor system 100 fluidized bed reactor includes a vessel 110, the recirculation circuit 122 and the distribution plate 128 that is located generally as described above. After reaching the condensing mode of operation the speed of the circulating gas passing through the polymerization reactor system 100 fluidized bed increases to a level sufficient to displace and, preferably, removal of the contaminant from the holes of the distribution plate.

In order to facilitate the reader in understanding the present invention and also to include various preferred variants of the present invention in the context of the present description, most of the following descriptions will be presented in relation to commercial gas-phase reactor system to obtain polyethylene. It should be remembered that this is done only with the help of do not limit the present invention by way of example.

The method of polymerization

Polymer clay is salonie reactor system fluidized bed In each of the above mentioned General preferred approaches and/or preferred options of the reactor vessel can be a part of the polymerization reactor system fluidized bed. Gas-phase reactions of polymerizate can be done in the polymerization fluidized bed reactor and in the reactor systems with a mixer or reactor polymerization blade type (for example, systems with a mixing layer), which include solids in a gaseous environment. The discussion below includes systems fluidized bed, in which, it has been found that the use of the present invention preferably and particularly advantageous.

Fluidized bed may typically include a layer of particles, in which the static friction between the particles is broken. In each of the above mentioned General preferred approaches and/or preferred options system fluidized bed can be an open or closed system with a fluidized bed. Open system fluidized bed may include one or more fluid and one or more types of fluidized solid particles, and has one or more surfaces of the fluidized bed, exposed to the open unregulated atmosphere. For example, an open system with a fluidized bed may be an open container such as a tank without the top cover, or open borehole reactor periodic action or set parallel is but reactor periodic actions (for example, microtiter camera). Alternatively, the system fluidized bed can be closed. Closed system with fluidized bed may include one or more fluid and one or more types of fluidized particles, which, in General, limited by the barrier so that fluids and particles are retained within the system. For example, a closed system with a fluidized bed may include a pipeline (for example, for transport of the particles); a recirculation system with a fluidized bed, for example, the polymerization reactor system with a fluidized bed shown in figure 1, each of these systems can be installed in different places and connected with a commercial and/or industrial applications.

Closed system with fluidized bed can have a message fluid with an open system with a fluidized bed. Message fluid between the closed and open systems fluidized bed can be isolated, for example using one or more valves. Such isolation valves can be configured, designed for unidirectional flow of a fluid medium, for example, they may represent a dump valves or check valves. In General, the system fluidized bed (open or closed) can be the ü limited created (for example, man) boundaries, including one or more barriers. One or more barriers that define the established boundaries can, in General, be made of natural or synthetic materials. In addition, in General, the system fluidized bed (open or closed) can be a flow-through system, for example a system with a continuous flow or semi-continuous flow (for example, with variable flow), the system of periodic actions or system properities action (sometimes called semi-continuous system). In many cases, a system with a fluidized bed, which represents a flow-through systems are closed systems fluidized bed.

Fluidized bed in a particularly preferred variants are usually formed by a flow of gaseous fluid flowing in the direction opposite to gravity. The frictional resistance of the gas arising from the interaction of gas with solid particles exceeds the force of gravity and maintains the particles in a fluidized condition, which is called fluidized bed. To maintain acceptable fluidized bed shows the velocity of the gas passing through the bed must exceed the minimum flow velocity required for fluidization. The increased flow of oigushariduse increases the degree of movement of the particles in the layer and may result in favorable or unfavorable chaotic mixing of particles. The decrease in the flow leads to a decrease in the resistance experienced by the particles, which eventually leads to a fall in the layer. Fluidized layers formed by the gases flowing in directions other than vertical, include particles flowing through a pipe in the horizontal direction, the particles flowing down, for example, through the drain pipe, and so on.

Generally speaking, traditional fluidized bed polymerization process for obtaining resins and other polymer is generated by continuously passing a gaseous stream containing one or more monomers through a reactor with a fluidized bed in the reaction conditions and in the presence of catalyst at a rate sufficient to maintain a layer of solid particles in suspension. A continuous loop is used if the circulating gas stream, which is also called the circulatory flow, recirculating flow or pseudoviruses environment, is heated in the reactor by using the heat of polymerization. Hot gas stream, which also contains unreacted gaseous monomer is continuously discharged from the reactor, compressed, cooled and returned to the reactor. The product is unloaded from the reactor, and the system add make-up monomer, for example in the circulating stream or into the reactor, with the aim of substitution polimerizovannaja. See, for example, US patents 4543399, 4588790, 5028670, 5317036, 5352749, 5405922, 5436304, 5453471, 5462999, 5616661, 5668228 and 6689847. Basic traditional system of fluidized bed shown in figure 1. The reactor vessel 110 (also referred to as the reactor includes a reaction zone 112 and zone speed reduction 114. Although figure 1 shows the configuration of a reactor, comprising, essentially, a cylindrical part for the extended partition, you can also apply an alternative configuration, such as configuration, including fully or partially conical reactor. In such configurations, the fluidized bed can be inside a conical reaction zone, but below the area with the increased cross-sectional area, which serves as a zone speed reduction in a more traditional configuration of the reactor shown in figure 1.

The reaction zone 112 includes a layer of growing polymer particles, formed polymer particles and a small amount of catalyst, all of them are maintained in fluidized condition by means of a continuous flow capable of polymerization and modifying gaseous components including inert substances, in the form of a make-up stream, and recirculating the fluid passing through the reaction zone. To maintain acceptable fluidized bed shows the velocity of the gas passing through the bed must exceed the minimum is the optimum flow rate, required for liquefaction, which typically ranges from about 0.2 to about 0.5 ft/s for polyolefins (at normal operating temperatures, pressures and densities of the gas). Traditionally given gas velocity does not exceed 5.0 ft/s, typically less than about 2.9 m/s Typical values of gas velocity in the first mode, therefore, range from about 0.7 to about 2.9 m/s, although it can be higher.

The expression ' the speed of the circulating gas" and "given the speed of gas" in the present description is used to describe the velocity of the gas stream entering the reactor through the circulation (or recirculation) loop 122 in the reactor section of the fluidized bed reactor vessel 110, respectively. These speeds are closely related. In General, the speed of the circulating gas greatly exceeds the given velocity of the gas in the power of reduced cross-sectional area of the gas flow circuit. When considering the limiting case of zero speed of reaction in the system speeds shown are related simply through the relations of space,

$$V_{BC}=\frac{A_B}{A_{RC}}\cdot V_{S}yp\mathrm{and}\mathrm{in}nen\mathrm{and}\mathrm{e\; <mtext></mtext>\; <mn>\; 1,\; </mn>}$$

where V_RCrepresents the velocity of the circulating gas, V_Sis the present velocity of the gas, And_Brepresents the cross-sectional area fluidized bed, a a_RCrepresents the cross-sectional area of the circulation path of the gas. In the case of nonzero reaction rate ratio between the two speeds is complicated due to several factors, including the consumption of gas in the fluidized bed due to the reaction, the temperature change observed in the compressor, adding make-up gas in the gas circulating circuit of the reactor and the formation fluid downstream from the cooler (in condensing mode). However, given the fact that the conversion of monomer in a single pass through the fluidized bed is usually only about 2-5%, the above equation still provides a rough estimate of the ratio between the two gas velocities with an accuracy of within about 15%.

When you run into the reactor usually load the layer of polymer particles, to flow gas. These particles contribute to the prevention of the formation of localized "hot spots" at the beginning of the filing of the catalyst. These particles can constitute obtained in the process of gender is taken or another polymer. If it is another polymer particles are preferably removed together with the particles their desired polymer in the form of a first portion of the product. Ultimately, a fluidized bed of particles of the desired polymer displaces the initial layer.

Fluidization provide with high flow speed of the circulating gas fed to the layer and passing through the layer, usually this speed is about 20-50 times higher than the rate of flow of feed fluid. Such a high rate of recirculation provides the desired given the velocity of the gas required to maintain the fluidized bed. In General, fluidized bed has the appearance of a bubbling mass of the liquid, and the bubbles are formed by passing the flow of gas through the layer. (Mixing layer provides exactly the upward flow of bubbles.) The pressure drop in the layer is generally equal to or slightly greater than the mass of a layer to the area of its cross section.

Referring again to figure 1, make-up fluids can be submitted at the point 119 through line 111 and the circulation path 122. The composition of the circulating flow is usually determined using a gas analyzer 121, after which the composition and quantity of feed flow adjust accordingly to maintain essentially stable composition the composition is in the reaction zone. Gas analyzer 121 may be located so that it receives gas from a point located between the zone speed reduction heat exchanger 114 and 124, preferably, between the compressor 130 and the heat exchanger 124.

To ensure complete fluidization, the circulation flow and, if required, at least part of the feed stream can be returned to the reactor through a circulation circuit 122, for example in the inlet 126 located below the layer. Preferably, above the point of return is a gas distribution plate 128, contributing homogeneous fluidization layer and the supporting solid particles before the system starts up or when it is off. The flow upwards through a layer that facilitates the removal of the exothermic heat of polymerization reaction.

Part of the gas stream flowing through the fluidized bed, which is not entered into the reaction layer becomes a circulating stream leaving the reaction zone 112 and sent to the zone speed reduction 114 located above the layer in which most of the captured particles fall back into the layer, thereby reducing the transfer of solid particles.

Then the circulation stream is compressed with a compressor 130 and passed through a heat exchanger 124, in which the circulation flow to remove the heat of reaction and then the flow returns to the layer. It should be noted that the heat exchanger 124 may also be located before the compressor 130. An example of the heat exchanger 124 can serve as a shell-and-tube heat exchanger in which the recirculated gas passes through the pipes.

Circulating stream leaving the heat exchange zone, then return to the reactor at its base, and then in the fluidized bed through a gas distribution plate 128. The vent of the fluid flow 132 preferably installed at the entrance of the reactor to prevent deposition and agglomeration with the formation of a hard mass in the reactor the polymer particles, and to maintain in a captured state, or re-capture any particles or liquids that may Deposit or withdraw from the occupied state.

In this preferred embodiment, the product is unloaded from the line 144. Although not shown, it is desirable to separate fluids from the product, and return them to the reactor vessel 110.

In accordance with one of the preferred variants of the present invention, the polymerization catalyst into the reactor in solid or liquid form at the point 142 and passing through line 148. If you want to add one or more socialization that often exercised when using catalysts of the Ziegler-Coloring, one or more acetalization can be entered separately in the region of the promotional area, they will react with the catalyst with the formation of the catalytically active reaction product and/or affect the reaction occurring in the reactor system. However, the catalyst and socialization (socializaton) can be mixed prior to their introduction into the reaction zone.

Technological additive can be added to the reactor system 100 in situ by means of appropriate equipment, such as supply line 148 or other supply line 150.

The reactor shown in figure 1, is particularly well suited for obtaining polyolefins, such as polyethylene, polypropylene and so forth. Process conditions, raw materials, catalysts and the like, intended for the education of various polyolefins and other reaction products described in the references given in this description. Illustrative conditions of polymerization reactions in General are listed below to ensure General management.

The reactor vessel, for example, has an internal diameter of at least about 2 feet, usually more than about 10 feet, and it can exceed 15 or 17 feet.

The reactor pressure in a gas phase process may vary from about 100 lb./psi (Rel.) (690 KPa) to about 600 lb./psi (Rel.) (4138 KPa), preferably from about 200 lb./psi (Rel.) (1379 KPa) to about fot./psi (Rel.) (2759 KPa), more preferably, from about 250 lb./psi (Rel.) (1724 KPa) to about 350 lb./psi (Rel.) (2414 KPa).

The temperature in the reactor in a gas phase process may vary from about 30°to about 120°C. In one approach, the temperature in the reactor is lower than the melting point of the obtained polyolefin, the amount of less than about 40°C, 30°C, more preferably less than about 20°C., even more preferably less than about 15°C. the Process can be carried out even at higher temperatures, for example less than about 10 or 5°C lower than the melting point of the obtained polyolefin. For example, the melting temperature of the polyethylene is from about 115 to 130°C.

The General temperature in the gas-phase process typically ranges from about 30 to about 125°C. In one approach, the temperature at the point of the reactor system with the highest temperature lower than the melting point of the obtained polyolefin, the amount of less than about 30°C., more preferably, less than about 20°C., even more preferably less than about 15°C. In such a system, as shown in figure 1, the point with the highest temperature is usually the outlet of the compressor 130.

Other gas-phase processes included in the scope of the present invention include the sequence of the part or multi-stage polymerization processes. In addition, gas-phase processes included in the scope of the present invention include are described in patents US 5627242, 5665818 and 5677375, and European publications EP-A-0794200, EP-B1-0649992, EP-A-0802202 and ER-IN-634421.

In any of the described in this description of the preferred options the operation of gas-phase process can be done in condensing mode, which is described in more detail below.

In one of the preferred options the reactor used in the preferred embodiments of the present invention capable of producing more than 500 lbs of polymer per hour (227 kg/HR) up to 300,000 lb./h (90900 kg/HR) or higher of polymer, preferably from more than 1000 lb./HR (455 kg/HR), more preferably, more than 10,000 lbs./HR (4540 kg/HR), even more preferably, more than 25,000 lb./h (11300 kg/HR), even more preferably, more than 35000 lb./h (15900 kg/HR), even more preferably, more than 50,000 lb./h (22700 kg/h), most preferably from more than 65,000 lb./h (29000 kg/h) to more than 100,000 lb./h (45500 kg/h).

Another example of a polymerization reactor system 200 fluidized bed is shown in figure 2. In accordance with the drawing, the system 200 is recirculated, it includes low-inertia vertical tubular reactor 202, a vertical pipe 204 downdraft and the circulation pump 206. The monomer (monomers) and the catalyst serves circulating the circuit 208 in the substrate 210. In the system of this type, the polymerization product is formed mainly in the low-inertia vertical reactor 202, but continues to grow throughout the system. Particles of a polymer obtained in the low-inertia vertical reactor 202, pass through line 212 in the upper inlet 214 of the descending pipe 204. The polymer particles accumulate in the descending pipe, in which they move down in the composition of the dense slow current layer. Layer formed in the descending pipe, can be considered as a fluidized bed. Particles of the polymer product is discharged from line 216. Although not shown, it is desirable to separate from the product fluid environment, and return them to the reactor system 200.

The condensation mode

In any of the described in this description of the preferred options work polymerization reactor system can be implemented in condensation or supercompensation modes (which are together referred to as "condensing mode"), in which the circulating gas stream is cooled to a temperature below its dew point with obtaining a mixture comprising a liquid and a gas phase, which may also contain a small amount of gone solid polymer particles. Preferably, in the process introducing inert capable of condensing liquid to increase the cooling capacity of the reactor of your system inert capable of condensing fluid medium is usually called (input) condensing substances (condensing agents), or UTC. One particularly preferred condensation of substances is isopentane, although it is possible to use other substances. In more detail the processes of condensation regime described in patents US 5342749 and 5436304, as well as in patent publication US 2005/0267268 A1.

When carrying out the condensation with condensing substances from the reaction system, you can take more heat, thus, the productivity of the polymer is greatly increased.

In one of the approaches of the circulating gas stream is cooled to a temperature below its dew point with obtaining a mixture comprising a liquid and a gas phase, which may also contain a small amount of gone solids, such as particles of polymer, catalyst, etc. In one of the preferred options work in condensing mode is carried out in accordance with the method and with the use of the equipment described in the patent US 4588790. In preferred embodiments of the present description can also apply to the practices described in previously published patents that describe the polymerization condensation mode, for example, in US patents 4543399, 5436304, 5462999, 6391985, 5352749, 5405922, 6455644 and the European patent 0803519 A1.

Working conditions

Operating conditions of the reactor and other systems are not particularly critical to the present invention. Although the above is bsie working conditions of a polymerization reactor systems fluidized bed, system fluidized bed and systems without liquefaction can work in a wide range of conditions, in addition to the above, in respect of temperature, pressure, flow velocities, fluid, etc.

Clogging of the distribution plate and its elimination

As noted above, the authors of the present invention unexpectedly discovered a method of cleaning distribution plate reactor polymerization in the fluidized bed, for example, a commercial reactor UNIPOL™, during his work. This discovery is very advantageous because it eliminates the need to stop the reactor system to clean switch plates. The following description explains how to displace contaminants from the holes of the distribution plate and, in some cases, for complete cleaning of the holes from contaminants applied to the high speed circulating gas.

This finding is directly contrary to generally accepted opinion, whereby to prevent entrainment of product and catalyst circulation gas flow should be using the low speed of the circulating gas, and the specified fly ash is considered the main cause of the plugging of the distribution plate and heat exchanger.

Observed that the clearance holes of the distribution plate is reduced due nakoplenie the contaminants. In General, the obstruction increases from the inner surface of the hole and slowly closes them.

The authors of the present invention investigated the performance of the installation for the production of polyethylene commercial scale, in which the use of metallocene catalyst, in this setting, the clog is removed from a distribution plate by adjusting operating conditions, therefore, need to stop the reactor with the purpose of mechanical treatment did not occur. Although the exact mechanism is currently not studied in detail, not wanting to be limited by any theory, believe that the method of purification is affected by two factors: (I) the temperature at the inlet exceeding a generally applicable, and (II) the velocity of the circulating gas in excess of commonly used. There is an assumption, namely, that elevated compared to the normal temperature at the inlet (a consequence of operating at high speed) allow condensed in the lower arch reactor liquids to expand and release the deposition of polymer on the plate substantially to the deposition has been displaced and removed from the gas at high speeds.

The reason for the increase in the normalized velocity of the gas increases the temperature of the circulating gas at the inlet of the reactor, are well known to persons skilled in this area and equipment, and it can be explained when considering the heat balance in the system.

Typically, the reactor operates at a fixed reaction temperature fluidized bed T_RX. To maintain this temperature it is necessary to remove heat exothermic reaction generated during the production of polymer in the fluidized bed. This is carried out by cooling the inlet gas to a temperature which is significantly lower than T_RX. Gas temperature coming into the fluidized bed through a distribution plate) is heated in contact with the layer having a higher temperature, thus, it is possible to remove a portion of heat equal to the increase in enthalpy of the gas.

In addition, if the reactor operates in condensing mode, removes excess amount of heat due to the evaporation of the liquid at its entry into the fluidized bed. An additional amount of heat equal to the heat of vaporization of the liquid. (Heat removed by the liquid, also called the latent heat of evaporation.) The total amount of heat equal to the amount of increase of the enthalpy and heat of vaporization of the gas. It should be noted that if all other variables of the system remain constant, the rate of heat removal through both of these mechanisms are numerically proportional to the flow velocity of circulation the aqueous gas.

During normal operation, the reaction temperature T_RXmaintain at a constant level by balancing the rate of formation of heat and rate of removal of heat from the system. This is carried out by adjusting the gas temperature at the entrance with automatic temperature control. For example, if you discovered that T_RXexceeds the desired (i.e. a given temperature, the automated control system will adjust the conditions in the circulating gas cooler to reduce the temperature of the inlet gas. This will increase the cooling layer and, thus, reduce the temperature to a specified level.

The explanation of why the increase in reduced gas velocity causes an increase in the temperature of the circulating gas at the inlet of the reactor, therefore, can result in the following way. When the performance of the reactor, the rate of heat generation is constant and the required rate of heat removal is also constant. If the speed of the circulation gas is increased, the dissipation rate has also increased, and the temperature T_RXstart to decrease (because the dissipation rate temporarily exceeded the rate of heat generation). Thermoregulatory system has detected the reduction temperature and automatically increase the gas temperature at the inlet that is, to the temperature of the layer was reduced to the specified value.

In the process, which applied work in condensing mode, the condensate is usually accumulates in the lower part of the reactor, below the distribution plate. This accumulation of fluid watched intensely swirling mass of liquid in the lower arch, stir the flow of the circulating gas flowing from the inlet of the reactor and vent flow inlet. The amount of this condensed liquid can reach thousands of pounds of suspended liquid. Previously it was thought that such accumulation of fluid should be avoided because it may cause problems with the stability of the fluidized bed. For example, the relative small increase in the temperature of the circulating gas can cause partial or complete boiling accumulated fluids that will lead to a sudden increase in the concentration of co monomer and a condensing agent in the layer of fluid that can lead to excessive stickiness in the fluidized bed, the reduction of fluidization and the formation of clots.

However, for the purposes of the present invention, without wishing to be bound by theory, believe that clearing caused by softening and gradual dissolution of the polymer blockage formed at elevated temperature (a temperature increase of prevadid increase speed). Polymeric contaminant softened in two ways: directly, as a result of increasing temperature, and not directly in the presence of the phenomenon of plasticization caused by increasing the amount of hydrocarbons absorbed pollutant. (It is well known that the solubility of hydrocarbons in the polymer significantly increases with temperature.) Softening leads to the fact that the clog slowly dissolves in the presence of hydrocarbons. Believe that such dissolution is one of the mechanisms leading to the separation of contaminants from the distribution plate.

Another possibility is that the clearance caused by exposure to a high-speed collision of liquid droplets and polymer contaminants in the holes. In fact, the increased gas velocity can be cleaned by exposure to similar water-jet cleaning.

How to clean switch plates

Figure 3 shows a method 300 clean switch plates in a polymerization reactor with a fluidized bed in accordance with one of the preferred options. As shown, the method includes, in the first mode, the operation under normal underlying present rate of gas in the polymerization reactor system with a fluidized bed, for example, op is pulling above (see stage 302). Speed can be measured at any point in the system, for example in the recirculation loop, heat exchanger, reactor vessel or its parts, etc. In the second mode shows the velocity of the gas increases to values larger than the base value of the first mode, to a level sufficient to increase the temperature of the circulation gas in the inlet to a temperature above the average temperature of the circulation gas in the inlet port in the first mode, and to a level sufficient to displace and, preferably, removal of the contaminant from the holes of the distribution plate (see stage 304).

Again, it should be noted that in this and other preferred embodiments, this does not necessarily mean that the clog is removed immediately from the holes. It also does not mean that the removal of the obstruction is only circulating the gas, although this may be so. In addition, this does not mean that all contaminant is removed in all cases. Rather, as will be clear hereinafter, before you remove appreciable quantities of pollutants may take several hours or days. Moreover, without wishing to be bound by any theory, believe that the removal of the obstruction contributes to the totality of conditions, including the above-mentioned higher than normal temperatures at the inlet exceeding the surrounding normal speed of circulation of the gas and the possible contact of the condensed liquid from contaminating substance. Additionally, it may be desirable to resume normal operation after removal of sufficient quantities of pollutants.

In General, the speed of the circulating gas can be adjusted by controlling the circulation compressor. In the first mode, during normal operation of the installation, base shown the velocity of the gas ranges from 2.1 to 2.9 ft/s (from 0.64 to 0,884 m/s).

Given the speed of the circulating gas passing through the reaction zone of the reactor vessel in the second mode exceeds the base value in the first mode. In the second mode shows the velocity of the gas may be more than 2.5 ft/s (more 0,762 m/s), more preferably, more than about 3.0 ft/s, for example, 3.1 ft/s (0,94 m/s), 5.0 ft/s (1.5 m/s), 6.0 ft/s (1.8 m/s), 7.0 ft/s (2.1 m/s), etc. In a typical reaction obtain polyethylene these speeds circulating gas are at a level sufficient to raise the temperature of the circulation gas in the input the hole to levels higher than the average temperature of the circulation gas inlet in the first mode, and to a level sufficient to displace and, preferably, removal of the clogging of the holes of the distribution plate.

Again, the values and ranges below in the present description, given only as examples and are not intended to limit the scope of the crust is asego invention. Persons skilled in the art it will be clear that it is possible to apply the values and ranges, other than shown above and elsewhere, and they can be used depend on the specific process parameters for the implementation of the preferred variant of the present invention.

As described in more detail below, the cleaning may take several days, for example a week or more. Although the exact mechanisms of the processes are not fully known, believe that cleaning is carried out by changing the equilibrium pollution/treatment, which may occur in the reactor system. Thus, the formation of impurities at work (if they occur) can be suppressed, for example, by increasing the technological content of the additive and increase the speed (in comparison with such content processing AIDS/speed at which during operation are formed blockages).

The first mode may be an operation at startup, for example, as described above. As noted above, the inclusion of the reactor may be a particularly problematic form of clogging plates, called corsacorta. Not wishing to be bound by theory, believe that corsacorta is the result of the formation and subsequent separation of small plates in the lower arch (under distribution plate)Schitaet, these little plates are formed as a result of the transfer and acquisition charge of catalyst in the gas flow circuit of the reactor. Highly charged catalyst may stick to the walls in the lower arch and form small plates react with ethylene and other reactive gases present in the circulating gas. Accordingly, to clean switch plates from clogs and sirsasana you can apply the techniques described in the present description.

The first mode may be a work in stable mode, for example, after completion of the run, and he can be a work in condensing mode. For example, during operation in the first mode, you can monitor the degree of clogging of the distribution plate. When it detects the clogging of the distribution plate above a certain limit, etc. you can start a second mode.

After some time of operation in the second mode, the system can be returned to the first mode. More preferably, in the second mode, monitor the degree of clogging of the distribution plate, and after a predetermined number of contaminants were removed from the distribution plate, the system returns to the first mode. The amount of contaminants that you have is Alice, set on the basis of reducing clogging in percent, as the target maximum number of contaminants that you want to delete, etc.

You can apply any method of estimating the number of contaminants in the distribution plate, for example, detect changes in the pressure drop in the distributor plate at a given set of conditions, violations of the tracking layer or anomalies, usually observed when the clogging switch plates, etc. In most commercial methods of work used measurement of the pressure drop together with the determination of the geometry of holes, number of holes, the density/viscosity of the gas and the velocity of the gas stream. You can then calculate the degree of clogging in percent based on the amount of interest is fully blocked holes, corresponding to the observed pressure drop. Work in condensing mode can be caused by the decrease of the nominal volumetric flow rates of gases to the value corresponding to the mole fraction of condensed gas.

Figure 4 shows a method 400 clean switch plates in a polymerization reactor with a fluidized bed in accordance with another preferred option. At stage 402 in a polymerization reactor system fluidized bed track the quantity which has to contaminants in the distribution plate. Tracking can be performed during start-up, operation in a stable mode, etc.

At stage 404 to determine whether the decrease of the degree of clogging of the distribution plate. Such determination may be based on any criteria. In a simple approach, if the degree of contamination exceeds a certain limit, it is possible to carry out cleaning. In more complex approaches in the determination can take into account many factors such as the degree of clogging of the distribution plate, the observed violations layer, etc.

If monitoring indicates that it is desirable or necessary to reduce the degree of clogging of the distribution plate, the velocity of the circulating gas passing through the recirculation circuit is increased to a level sufficient to displace clogging of the holes of the distribution plate (see stage 406). It should be noted that the increased speed of the circulating gas can also increase its temperature at the inlet of the reactor vessel.

As above, the system can return to a previous state based on some criteria, such as after some time, the quantity of the removed contaminants, etc.

Figure 5 shows a method 500 of obtaining the polymer in the polymerization reactor with a fluidized bed. At stage 502 polymerization reactor system with p is authorizenet layer, for example, the above-described start. At stage 504 after reaching the condensing mode of operation the speed of the circulating gas passing through the recirculation circuit is increased to a level sufficient to displace clogging of the holes of the distribution plate. The achievement of the condensation mode of operation may allow the aforementioned accumulation of fluid in the lower part of the reactor vessel below the distribution plate.

As above, the system can return to a previous state based on some criteria, such as after some time, the quantity of the removed contaminants, etc.

In addition, it should be noted that in the above described first and second modes of operation can be maintained approximately full capacity.

Technological additive

In any of the described in the present description approaches may be desirable counter-ash solids circulating gas stream, which is usually observed at high flow rates used to displace and, preferably, removal of the clogging of the plates. Accordingly, in the reactor can inject an additive, such as a technological additive, in an amount effective to reduce entrainment of solids from the reactor vessel into the circulation flow while increasing the military speed circulating gas during the cleanup phase.

Technological additive that you can add or not add, facilitates the cleaning process by reducing the entrainment of resin and catalyst, which otherwise would have blocked the plate or cooler at higher flow velocities. Moreover, if applied to reduce the entrainment technological additive, it is possible to apply an even higher speed of the circulating gas, so you can increase the effectiveness of the methods described in the present description.

Examples of additives include antistatic agents, which has been the subject of numerous publications. For example, in patent EP 0453116 A1 describes the introduction of antistatic additives into the reactor in order to reduce the number of plates and agglomerates. In the patent US 4012574 described by adding to the reactor surface-active compounds containing perfluorocarbon group, in order to reduce clogging. In WO 96/11961 described antistatic agent designed to minimize clogging and the formation of plates in the gas, suspension polymerization or polymerization with a liquid reservoir, and the additive is a component of the deposited catalytic system. In patents US 5034480 and 5034481 described the reaction product with traditional titanium catalyst of the Ziegler-Coloring, including antistatic agent, with the formation of the ethyl is new polymers with ultra-high molecular weight. For example, in WO 97/46599 describes the use of soluble metallocene catalysts in gas-phase process, and they are served in the depletion zone of the reactor polymerisation receipt of stereoregular polymers. In WO 97/46599 also described that the stream of catalyst may contain stabilizers or anti-static agents, such as ATMER ® 163 (commercially available and supplied by ICI Specialty Chemicals, Baltimore, Maryland).

In the patent US 5026795 described adding an antistatic agent, together with a liquid medium in a polymerization zone in gas-phase polymerization reactor. Preferably, the antistatic agent is mixed with the diluent and injected into the reactor with the help of media, including comonomer. The preferred described antistatic agent is a mixture of having trademark STADIS® 450 (DuPont), which contains a polysulfone, a polymeric polyamine, sulfonic acid and toluene.

In EP 0811638 A2 describes the use of metallocene catalyst and activating socializaton in the polymerization process in the presence of an antistatic agent also described the use of ATMER 163. In EP 0811638 A2 also describes the different ways of introducing an antistatic agent, most preferably sprayed into the fluidized bed in the reactor. Another described method is the addition of an antistatic agent which together with the flow caused or liquid catalyst until while the antistatic agent will not affect the catalysts largely or poison them. EP 0811638 A2 includes examples in which the applied catalysts were introduced in suspension in mineral oil before introduction to the reactor, and an antistatic agent was injected directly into the reactor when using nenalezena catalysts. In the fluidized bed was measured static charge at a height of several feet above the distribution plate. Preferably, the antistatic agent was added in an intermittent mode in response to a change of charge, such as increasing the level of static electricity.

Technological additive can be introduced into the reactor using any known method.

In the illustrative embodiment, production, technological additive is present in the mixture of catalyst/media/technological additive content of about 3%±2% by mass.

Observed that the use of stearates of aluminum, for example distearate aluminum, reduces the level of ash in the implementation of the production of polyethylene using metallocene catalysts. One particularly preferred additives is SA-200, supplied by Univation Technologies (address sales 5555 San Felipe, Suite 1950, Houston, Texas, United States. Assume that other mixtures technologist is ical additives, for example, SA-300, will also be effective.

In the illustrative example, the production, the active ingredient technological additives are added in amounts of about 5 hours/million±5 PM/million based on the performance of the reactor system during the cleaning period. For example, if the system produces 100000 kg/h of polyethylene, during the cleanup phase and add approximately 500 g distearate aluminum per hour.

Determine whether the introduction of technological additives, as well as the added amount may be based on the amount of solid substances, carry out the circulating gas stream. The number gone solids can be evaluated in any traditional way. In one illustrative approaches the acoustic sensor detects the thuds of solid particles on the walls of the circulation loop. The frequency of the shock can then be used to estimate the number carried out solids. In another illustrative approach established in the recirculation path of the optical sensor detects solids, passing by him.

Those employing the present invention, it should be remembered that some technological additives can affect the performance of the catalyst. If such a case occurs, you should choose low content of processing AIDS.

Por what measures

It should be understood that although the present invention has been described in conjunction with specific preferred variant, the above description is intended to illustrate and not to limit the scope of the present invention. Other aspects, advantages and modifications will be apparent to persons skilled in the art that the present invention applies.

Therefore, the following examples are intended to provide those skilled in the art, a complete description of how to make and use the compounds of the present invention, and are not intended to limit the scope of what the inventors believe his invention.

All cycles in the gas-phase catalytic reaction process, the ethylene was subjected to polymerization. The diameter of the reactor vessel was 14.5 feet (4,42 m), and its vertical dimension (the height of the neck) was 44.5 ft (13,56 m) from the top of the distribution plate. All cycles were applied catalyst HP-100, supplied by UNIVATION TECHNOLOGIES, sales Department which is located at Houston, TX, 77056.

Example 1 (comparative)

The graph 600 shown in Fig.6, shows a typical profile of clogging of the plates depending on the time after reaching the condensation mode at time 0 days for the FPIC of the BA, carried out in accordance with the above parameters, without the use of processing additives.

In this comparative example shows a typical case in which the speed of the circulation gas remains approximately constant. It is shown that clogging of the distribution plate is observed at time 0 days and continues to accumulate during the data collection process. Traditionally it would be desirable to shut down the reactor system and remove distribution plate while achieving a 40% blockage. This example shows that the contamination has reached 40% in about the 11th day of work.

Example 2 (comparative)

The graph 700 shown in Fig.7, shows a typical profile of clogging of the plates depending on the time after reaching the condensation mode at time 0 days for a method implemented in accordance with the above parameters, without the use of processing additives. In this example, there is corsacorta that leads to failure in less than two days.

Example 3

The graph 800, shown in Fig, shows the profile of the clogging of the plates depending on the time after reaching the condensation mode at time 0 days for a method implemented in accordance with the above parameters, using technological additives SA-200, supplied the my Univation Technologies (address sales: 5555 San Felipe, Suite 1950, Houston, Texas, 770556, USA.

As shown, the velocity of the gas is increased to about 2.6 ft/s in about a day. Also during the cleaning process was added technological additive. The blockage was reduced to slightly more than 10% after about 8 days.

Although not shown, later given the velocity of the gas was reduced to less than about 2.5 m/s to operate in a stable mode.

After the cleaning process after starting it is expected that the contamination distribution plate during operation in a stable mode at low speeds the circulation of gas or will not grow or will grow slowly. Undoubtedly, the cleaning process can be applied to clean switch plates during stable operation.

Example 4

The graph 900, shown in Fig.9, which shows the profile of the clogging of the plates depending on the time after reaching the condensation mode at time 0 days for a method implemented in accordance with the above parameters, without the use of processing AIDS during the cleanup phase. Given the velocity of the gas was increased to about 2.5 ft/s without adding processing AIDS. Soon after increasing the speed of the circulating gas the clog has been removed from the distribution plate. After about 10 days sasieni is decreased to approximately 10%.

Example 5

The method was carried out in accordance with the above parameters without the use of processing AIDS during the cleanup phase. Given the velocity of the gas was increased to more than 2.5 ft/s without adding processing AIDS. Soon after increasing reduced velocity gas clogging of the distribution plate in a few days was reduced to about 24%, and then slowly increased until around time of 10 days. However, the degree of contamination remained constant at approximately 27-30% after about 10 days.

Unless otherwise stated, the expression "consists essentially of" and "consisting essentially of" does not exclude the presence of other steps, elements or materials, regardless of whether it is specifically in the present description, if such stages, items, or materials do not affect the basic and novel characteristics of the present invention, furthermore, they do not exclude impurities and changes commonly associated with the used items and materials.

In the interest of brevity in this description, explicitly described only certain ranges. However, any lower limit of the range can be combined with any upper limit with the purpose of obtaining a range not described explicitly in addition, any lower limit of the range can be combined with any of the other lower limit to describe the range not given in explicit form; similarly, any upper limit of the range can be combined with any other upper limit to describe the range is not given in explicit form. In addition, the ranges include every point or a single value that does not extend beyond the end point, although this was not stated explicitly. Thus, each point or a single value may serve as a lower or upper limit combined with any other point or a specific value or other lower or upper limit, to describe the range not stated explicitly.

All listed in this description priority documents, are fully incorporated in the present description by reference for all cases in which such incorporation is permitted, and to the extent that this inclusion is consistent with the description of the present invention. Additionally, all listed in this description of the documents and links, including testing methods, publications, patents, journal articles, etc. are included in the present description by reference for all cases in which such incorporation is permitted, and to the extent that this inclusion is consistent with the description of the present invention.

Although the present invention has been described with the exile of left-wing the a number of preferred options and examples persons skilled in the art having benefit of the present description, will appreciate that it is possible to develop other preferred variants, without departing from the spirit and letters of the invention described in the present description.

1. The way to clean switch plates in a polymerization reactor system, fluidized bed, including:
in the first mode, the implementation of work at about normal basic value of a given gas velocity in a polymerization reactor system with a fluidized bed, comprising a reactor vessel, circulation, and distribution plate located in the reactor vessel near its inlet;
in the second mode shows the velocity of the gas is increased to values greater than the base value in the first mode, to a level sufficient to raise the temperature of the circulating gas in the inlet hole to the values greater than the average temperature of the circulating gas in the inlet port in the first mode, and to a level sufficient to displace clogging of the holes of the distribution plate.

2. The method in accordance with claim 1, additionally comprising adding to the reactor system additives in amounts effective to reduce entrainment of solids from the reactor vessel into the circulation flow when the appreciation is authorized speed of the circulating gas.

3. The method according to claim 2, in which the additive is aluminum stearate.

4. The method according to claim 1, wherein the first mode is an exercise run, work in a stable mode or work in condensing mode.

5. The method according to claim 1, further comprising resuming the first mode after some time.

6. The method according to claim 1, further comprising tracking the number of contaminants in the distribution plate in the first mode.

7. The method according to claim 1, further comprising tracking the number of contaminants in the distribution plate in the second mode.

8. The method according to claim 7, further comprising resuming the first mode upon determining that a specified number of contaminants were removed from the distribution plate.

9. The method according to claim 1, in which the speed of the circulating gas is increased to at least 5 ft/s (1.5 m/s).

10. The method according to claim 1, in which the gas velocity increase for at least several hours.

11. The way to clean switch plates in a polymerization reactor system, fluidized bed, including:
tracking the number of polluting substances in the distribution plate located in a polymerization reactor system with a fluidized bed is at the forefront, including the reactor vessel, circulation, and distribution plate located in the reactor vessel near its inlet;
determine if you need to reduce clogging of the distribution plate; and
if the determination indicates that the pollution distribution plate must be reduced, increasing the speed of the circulating gas passing through the recirculation circuit to a level sufficient to displace polluting substances from the holes of the distribution plate.

12. The method according to claim 11, further comprising adding in the reactor system additives in amounts effective to reduce entrainment of solids from the reactor vessel into the circulation flow in the high speed circulating gas.

13. The method according to item 12, in which the additive is aluminum stearate.

14. The method according to claim 11, further comprising reducing the speed of the circulating gas after some time.

15. The method according to claim 11, further comprising reducing the speed of the circulating gas after determining that a specified number of contaminants were removed from the distribution plate.

16. The method according to claim 11, further comprising increasing the speed of the circulating gas passing through the circulation path to the Ural branch of the nya, sufficient to increase the temperature of the circulating gas in the inlet hole.

17. The method according to claim 11, in which the fluidized bed operates in condensing mode during tracking.

18. The method according to claim 11, in which the speed of the circulating gas is increased to at least 5 ft/s (1.5 m/s).

19. The method of obtaining the polymer in a polymerization reactor system with a fluidized bed, comprising the following stages:
start a polymerization reactor system with a fluidized bed, comprising a reactor vessel, circulation, and distribution plate located in the reactor vessel near its inlet; and
after reaching the condensing mode of operation increases the speed of the circulating gas passing through the recirculation circuit to a level sufficient to displace polluting substances from the holes of the distribution plate.

20. The method according to claim 19, further comprising adding in the reactor system additives in amounts effective to reduce entrainment of solids from the reactor vessel into the circulation flow in the high speed circulating gas.

21. The method according to claim 20, in which the additive is aluminum stearate.

22. The method according to claim 19, further comprising tracking the number of contaminants in the dissolved, deleteline plate during startup.

23. The method according to claim 19, further comprising increasing the speed of the circulating gas to a level sufficient to increase the temperature of the circulating gas in the inlet hole to a level above the average temperature of the circulating gas in the inlet hole being run.

24. The method according to claim 19, in which the speed of the circulating gas is increased to at least 5 ft/s (1.5 m/s).