The reactor for catalytic gas purification

 

(57) Abstract:

The invention relates to chemical apparatus and can be used for cleaning of gases from nitrogen oxides, neutralization of exhaust gases from organic impurities. Contains the bottom and cover with inlet and outlet fittings. The internal volume of the reactor divided by horizontal blank wall into two chambers, each of which iron gratings posted by layers of inert nozzles with catalyst on them that have established heaters. The partition is located between the upper and lower chambers connected by a vertical pipe-mixer located at the axis of the upper chamber. At the top of each camera installed horizontal mixers, in which there are electric heaters. Process for selective reduction of nitrogen oxides in the Central part of the pipe-mixer installed collector-spray of reductant supplied in the form of liquid or vapor phase. This device allows to reduce the intensity and cost of the reactor, to simplify it, while also improving reliability. 3 C.p. f-crystals, 2 Il.

The invention relates to chemical devices which, Brazauskas during the manufacture of nitric acid, the separation of sulfuric and nitric acids, etc. in Addition, the reactor can be used for catalytic neutralization of gas emissions from organic impurities.

Known contact apparatus for neutralization of exhaust gases from organic substances and nitrogen oxides in the so-called non-stationary mode [RF Patent 1829173, B 01 D 53/34, 1997; RF patent 2058186, 10.09.99, ed. mon. The USSR 1011950, B 01 D 53/34, 15.04.1983, ed. St. USSR 1535619, 15.01.90, pat. PL 154894, B 01 D 53/36, 28.02.1992; RF patent 2064331, B 01 J 8/04, 16.03.1994].

A characteristic feature of such devices is the need for heat in the chemical reaction zone for carrying out the process in autothermal mode. Typically, the exhaust gases have a low concentration of components to be cleared, their adiabatic heating is relatively low, and the process of neutralization in a stationary mode could not be implemented. Introduced into the reaction zone additional heat increases the adiabatic warming up to the value required to maintain the process of neutralization in autothermal mode.

The closest is the contact device described in [Pat. PL 154894, B 01 D 53/36, 28.02.1992]. The apparatus (Fig.1) consists of verticalheader. The casing is divided by a vertical partition into two chambers, in which a grid-iron lattice posted two of the same volume of the layer of inert packing, which poured on top of the same volume of the catalyst layers. At the bottom under the grate bars are fittings supply - gas outlet.

When the contact apparatus, the catalyst is heated to the temperature of the beginning of a chemical reaction, the cleaned gas is fed first to one chamber and exits from the apparatus through another camera. After a certain time, called politicla, the gas supply cameras change on the other, thereby making the non-stationary mode of neutralization. The heat of the chemical reaction is always in the catalyst layers. At low concentrations of the gases to be cleared when the heat of the chemical reaction for its holding in autothermal mode is not enough, additional heat introduced by the inclusion of heaters.

The construction of the contact apparatus of the prototype does not allow to do the cleaning gas in a more economical mode because of the relatively large heat loss to the environment - especially in the area of high temperatures (~400o

The invention solves the problem of simplifying the design of the device and increase reliability.

The problem is solved following the design of the reactor.

The reactor (Fig. 1) consists of a vertical cylindrical body 1 with the fittings I / o gas 2, a conical cover 3 and the flat bottom 4. The inner space is divided deaf horizontal partition 5 into two sections - upper and I lower II, interconnected by a Central supporting tube mixer 6 with internal turbulent partitions 7. Each cell on the grid-iron lattices 8 posted layer intertoy nozzles 9 (for example, rings process) and the top nozzle layer of the catalyst 10. The top of each chamber, above the catalyst bed is placed a removable packages of heaters in Heaters, razmesheniya a blank wall 13. In the upper chamber II cover 3 is shielded from heat additional partition 14. For selective catalytic purification of gases from nitrogen oxides in the middle of the mixer 6 has a collector-nebulizer gas 16 with holes connected by a pipe 15 with the nozzle 17 for supplying reductant (ammonia, ammonia water). For catalytic purification of gases from organic and other impurities installation parts 15, 16 and 17 is not required.

This technical result achieved from the use of the totality of the above-described essential features is to reduce the metal consumption and cost of the reactor, reducing heat loss to the environment and, consequently, reducing the amount of heat supply to the reaction zone.

The reactor is as follows.

Before you start the catalyst layers and the adjacent part of the inert nozzle is heated to 280-380oWith by feeding ambient air alternately through the socket 2 into the chamber I, then served exhaust gas with a temperature of 60-80oC. (Stroke gas during the first politicla shown in Fig.2, solid arrows). Cool the gas to be cleaned passes through the layer of inert nozzle 9 and the catalyst layer 10, the recovery proceeds at a rather high speed at 280-380oC. Simultaneously in a gas stream containing nitric oxide, through the spray manifold 16 serves a reducing agent, which in the course of the stream is mixed in the mixer 6, and then through the packages of heaters 11 and box 12, the reaction mixture was additionally stirred and enters the chamber II in the catalyst layer 10, where the nitrogen oxides finally restored, the heat of the reacted mixture is absorbed in an inert nozzle 9, after which the mixture through the side fitting 2 exit from the apparatus into the atmosphere.

After a certain period of time the direction of movement of the cleaned gas stream is changed to the opposite (second politicl) and the reaction mixture follows the same path but in the opposite direction (Fig.1 shows a dashed arrows). After a predetermined period of time, the direction of flow of cold gas is again changed to the opposite, thereby making continuous operation of the reactor in the so-called non-stationary mode. The number entered in the reaction mixture of heat is governed by the heaters 11, depending on the concentration of impurities in the purified gas.

The present invention has similar characteristics with the prototype.

Contact appartantly apparatus includes a vertical cylindrical housing, the bottom and the lid.

The contact device has two grates, which are layers of inert nozzle and the catalyst layers on them.

The contact device includes fittings for inlet gas to be purified and the purified gas output.

In the area between catalyst installed heaters.

The casing is divided by a partition into two chambers.

Distinctive features the following:

the casing is divided into two chambers by a horizontal partition;

cameras are placed in the housing one above the other;

the chambers are connected with each other by a vertical pipe-mixer, placed along the axis of the upper chambers;

removable heaters placed in a horizontal mixers with holes for the passage of gas through them;

process for selective reduction of nitrogen oxides in the Central part of the pipe-mixer installed collector-spray, which sum up the reducing agent in the form of liquid or vapor phase.

Example 1.

In Fig.1 shows the construction of the rector, designed for selective catalytic purification of gases from nitrogen oxides.

Gas efficiency of 5-10 thousand m33
(9,8 t).

The concentration of nitrogen oxides 2-3 g/m3,

The temperature of the nitrous gases 20-30oWITH,

The temperature of the gas in the system:

- the maximum in the reaction zone, 450oWITH,

- working in the catalyst bed, 320-350oWITH,

- input-output gas in the device variable for politicla 20-200oWITH,

- start chemical reactions 180-200oC.

The calculated hydraulic resistance of 400 mm of water. Art.

Total design capacity of the electric heater 56 kW.

For carrying out the process under specified conditions - gas volume, concentration, amount of catalyst and inert nozzles, hydraulic resistance and other requirements, the diameter of the reactor amounted to 2.8 m with a total height of 7.4 m

Estimated heat loss from the apparatus into the environment up to 10500 kcal/h (at ambient air temperature - 40oC), which is ~21% of the installed capacity of electric heaters.

Example 2 (prototype). Same as in example 1.

The calculated heat loss to the environment 32% more than in the apparatus in example 1, and constitute ~13860 kcal/h

Thus, the proposed design of the reactor more komro have the same thermal stresses.

1. The reactor for catalytic gas purification from nitrogen oxides, neutralization of exhaust gases from organic and other impurities bottom and cover with inlet and outlet fittings, divided by a partition into two chambers, each of which iron gratings posted by layers of inert nozzles with catalyst on them that have established heaters, characterized in that the partition separating the internal volume of the reactor, made of horizontal deaf and is located between the upper and lower chambers connected by a vertical pipe-mixer located at the axis of the upper chamber.

2. The reactor under item 1, characterized in that the upper part of each camera installed horizontal mixers.

3. The reactor under item 1 or 2, characterized in that the heaters are arranged in a horizontal mixers.

4. The reactor according to any one of paragraphs. 1-3, characterized in that the process for selective reduction of nitrogen oxides in the Central part of the pipe-mixer additionally installed collector-spray of reductant supplied in the form of liquid or vapor phase.

 

Same patents:

The invention relates to a method of igniting gas-phase chemical reactions in the presence of the solid catalyst

The invention relates to a method for production of ammonia from synthesis gas and Converter for its implementation

The invention relates to apparatus and method for improving the flexibility of the way the process of reactive distillation

The invention relates to the field of chemistry and relates to a reactor for the reaction of the fluid with the processing gas in the presence of a catalyst, with the first reaction zone contains a catalyst, a means of entering the fluid located above the first reaction zone to supply the specified reactor unreacted fluid, means of gas inlet located below the first reaction zone to supply the specified reactor unreacted processing gas out liquid located below the first reaction zone, to provide output from the specified reactor unreacted liquid, means the gas outlet located above the first reaction zone, to ensure the output from the specified reactor unreacted processing gas, and means by-passing the fluid specified in the first reaction zone, communicating with the specified zone of the reactor, to ensure by-passing part of this unreacted fluid bypassing part of this first reaction zone, the said means by-passing the fluid includes means regulation by-passing fluid to regulate if the reaction zone

The invention relates to a system for catalytic conversion and the method of carrying out exothermic reactions between, for example, propylene and hydropredict ethylbenzene to obtain propylene oxide using a solid heterogeneous catalyst

Catalytic converter // 2177363
The invention relates to catalytic converters for neutralization of toxic substances in exhaust gases of automotive engines

The invention relates to catalytic systems for the processing of exhaust gas to reduce emissions of volatile chemicals

The invention relates to processes for cleaning of gases from sulfur compounds, which can be used in gas, oil, chemical, petrochemical industries

The invention relates to a power system and can be used in the purification of flue gases of thermal power plants from oxides of nitrogen and oxides of sulfur

The invention relates to the field of process automation chemical cleaning of combustion products of nitrogen oxides from

The invention relates to a method of dry desulfurization of exhaust gas, wherein the exhaust gas generated in the combustion chamber and the contaminated fly ash, harmful gaseous substances and returned by the particles of solids, partially dedust in the first separator solids, then the exhaust gas is directed into the reactor with a fluidized bed, and to the exhaust gas serves at least one absorption means CaO and/or Ca(OH)2in a reactor with a fluidized bed by adding water set temperature 50 - 90oC, then the exhaust gas containing particulate matter away from the reactor with a fluidized bed and is directed to the second separator solids, with the first part of the solids separated in the second separator is sent to a reactor with a fluidized bed, and the second portion of the solids separated in the second separator, return into a cooled zone of the combustion chamber and the pipeline is removed from the cycle, the solids separated in the first separator

The invention relates to the purification of flue gases from sulfur oxides

FIELD: production of aluminum in cells with self-fired anodes, possibly processes for cleaning anode gases.

SUBSTANCE: method comprises steps of accumulating anode gases, preliminarily combusting them together with air in burner devices mounted in cells; supplying gas-air mixture after preliminary combustion of anode gases along gas duct to stage of dust and gas trapping and blowing out to atmosphere. Before supplying gas-air mixture from burner devices to stage of dust and gas trapping, it is fed to process for oxidizing roasting; heated up to temperature 800-1100°C and then it is cooled until 230-290°C and heat is used for production needs.

EFFECT: lowered content of carbon, resin and CO in exhaust gases.

Up!