Plastic tank high pressure, a method of monitoring the health of plastic container and device for its implementation

 

Plastic tank high pressure consists of two bottom parts and located between the Central part. The factor of safety bottom parts exceeds the factor of safety the Central part on 4-15%. In the method of monitoring the health of the cylinder to measure the increment of the external diameter of the cylindrical part of the cylinder under the influence of internal pressure. The device control performance cylinder comprises a support, are designed to hold plastic container, and at least one displacement sensor. Displacement transducer mounted on a support with the ability to measure the increment of the external diameter of the cylindrical part of the metal cylinder. The use of the invention will improve the security of the container and to provide continuous monitoring of the technical condition of the outer plastic shell. 3 C. and 16 h.p. f-crystals, 5 Il.

The invention relates to the field of gas appliances, and in particular to methods and devices for health monitoring composite high-pressure cylinders (VD), and can be used in the manufacturing process and operation of large metalloplastic points, gas stations etc). Primarily the invention relates to plastic cylinders, in which the outer plastic shell is the main load-bearing element of the body of the container and the metallic liner is sealed by the shell and has a thickness at which the material of the liner may be in the region of elastic-plastic deformation or close to it at normal working pressure.

The vessels working under pressure, and including large metal cylinders VD large capacity, are objects of increased danger, the destruction of which in operation may lead to serious consequences, to cause great damage.

Especially adverse consequences can be destruction, accompanied by the formation of fragments of the balloon.

Currently, the basis for the design of plastic bottles lay the criterion of ravnopravnosti design (Neusberg C. L., idiot, A. Stability and optimization of composite membranes. Knowledge (Riga), 1988 , page 11). In accordance with this criterion, the factor of safety corps cylinder is made equal, not less than 2.6 in relation to the magnitude of the work is almost simultaneous destruction of both the cylindrical part of the cylinder, and it bottoms (EN, Testimony on PM 14065). However, studies have shown that disruption of the Central cylindrical part of the body of the container occurs mainly along its generatrix, and the formation of fragments exposed to the bottom part of the container.

To prevent accidental damage control over the technical condition of plastic bottles. The choice of control methods is one of the essential objectives for safe operation of plastic bottles VD.

According to the Rules of design and safe operation of vessels working under pressure (PB 10-115-96), approved by resolution of Gosgortekhnadzor of Russia from 18.04.95 N 20 (hereinafter the Rules), metal cylinders are subject to mandatory technical inspection every three years. Technical examination includes, in particular, external and internal inspection of the tank and hydraulic (pneumatic) tests. The task of external and internal inspection of the tank is to identify visible defects: cracks, dents, deviations from geometric shapes (circle, depressions, dents, etc.), laminations and breaks the plastic power of the shell.

If satisfactory results of the external and strength of the plastic shell and the density of the metal liner of the container.

However, the technical examination carried out in accordance with these Rules every three years, does not provide a warning of destruction of the plastic container in the operation period between examinations.

In addition, technical examination is rather difficult for organizations operating metal cylinders of large dimensions. In accordance with these Rules, the examination can be performed only in specialized institutions, where the consumer must deliver the plastic container, and, in addition, requires the prior time-consuming preparation of cylinders (in particular, the removal of all removable devices cylinders, fill tank test fluid, drying and degreasing after testing and so on).

A long period of time (every three years) between each technical examination, high labor costs, increased risk of exploitation of large cylinders and high operating pressures drive the need for continuous health monitoring of such cylinders in operation to prevent disaster is maloplastichnyj cylinders, providing continuous monitoring of leakage of the working medium during operation of the cylinder (EN 2117853 C1 ). To ensure such control between power shell and liner along a helical line along the longitudinal axis of the cylinder is made gazoprovody channel, separated from the power shell gas-tight layer. The channel is connected with the pressure sensor. Tightness of the metal liner in Gazoprovod channel increases the pressure of working medium, which is recorded by the pressure sensors connected to the alarm device.

However, the known method of monitoring leakage of the working fluid for the patent RU 2117853 C1 allows you to control the tightness of the metal liner and does not provide as periodic technical inspection performed by the above Rules, identifying formed during operation of container defects and changes in physico-mechanical properties of the outer plastic shell that has a significant impact on the safe operation of plastic bottles, in which the outer plastic shell is the main bearing element and the metallic liner is sealed to the shell.

The present invention postavlja health plastic container, including the assessment of the technical condition of the external plastic shell, while providing continuous monitoring of the technical condition of the external plastic casing during operation of the cylinder, and at the stage of its manufacture, in order to increase the safety of plastic bottles. The present invention is the creation of the control device for the implementation of the proposed method.

The problem is solved in that in the composition of the high-pressure bladder containing two bottom and located between the Central part (mainly cylindrical), according to the invention the bottom of the tank is made with a greater factor of safety than the Central part.

The increase in the strength characteristics of the bottom parts of the container in comparison with the cylindrical part guarantees the destruction of the body of plastic container only in its cylindrical part, which occurs along its generatrix and eliminates splinters.

It is helpful to factor the strength of the shell of the container bottom parts exceeded the factor of safety of its Central part on a 4-15%.

That is the main exceptions splintering when the destruction of the plastic container while maintaining the low density of the plastic material of the container.

As mentioned above, the present invention mainly is implemented in a metal cylinder in which the wall thickness of the liner and the plastic shell is selected from the condition that the metal liner is sealed envelope with an operating pressure material of the liner may be in the region of elastic-plastic deformation, and the main bearing element of the body of the container is a plastic cover that mainly provides strength characteristics of the plastic container.

When designing plastic container the factor of safety corps cylinder to the cylindrical part selects at least 2.6 (the Rules), and for bottoms - large on 4-15%, for example from 2.7 to 3.0.

The problem is solved also by the fact that in the method of monitoring the health of plastic container, including the measurement of a given parameter, describing the technical condition of the container according to the invention the specified parameter is the increment of the external diameter of the cylindrical part of the plastic container under the influence of internal pressure.

Measurement of outer diameter increment (the value of the cross extended is on the influence of internal pressure.

It is known that plastic deformation of the shell depend on the total time during which the container is under the influence of excess pressure, and the magnitude of this pressure (load). During long-term operation and cyclic loading plastic container in a plastic shell accumulate damage, leading to a decrease in strength and increase the pliability of the plastic sheath at the same level of loading (internal pressure of the working environment).

In addition, under sustained loading of the container in its plastic shell is also developing creep. For reinforced plastics creep rates after loading monotonically decreases for a very considerable time, are usually much larger than the lifetime of the product, although the creep curve is a monotonically increasing function. However, at the stage immediately preceding the destruction of the plastic shell, the rate of creep of the plastic shell begins to increase.

As a result, when the same values of the internal pressure of the magnitude of the plastic deformation of the membrane during long-term operation, and especially before destruction, and grow.

The authors found that, for example, fiberglass cylinder high-capacity BD-40 settlement (also confirmed experimentally) the increment of the external diameter of the cylindrical part of the cylinder from the action of the working pressure is 0.7%. The increase in the increment of the external diameter of the cylindrical part of the cylinder more than 0.7% may indicate the reduction of the safety factor below an acceptable level (2,6). The increase in the increment of the external diameter of the cylindrical part of the container by more than 2.5% characterizes the technical condition of the fiberglass shell before destruction. In the case of increasing the increment of the external diameter of the cylindrical part of the container by more than 0.7% of this plastic cylinder must be operated with a lower margin of safety (lower working pressure), or not allowed to use.

For power shell made of other materials (e.g. carbon fiber, organoplastic) these values may vary slightly and depend on the module of material used and the thickness of the wall.

The comparison of calculated data on the radial displacement of a point on the cylindrical surface of the cylinder (outer diameter increment Qili what they pressure in pneumatic and/or hydraulic testing of cylinder radial displacements can be estimated workmanship outer plastic shell of the container and its durability when carrying out acceptance tests.

For plastic tank, passed acceptance tests, measured during these tests for a given internal pressure, for example for the maximum working pressure, the increment value of the external diameter of the cylindrical part is accepted as valid values, which are compared to the values measured on the same internal pressure during cyclic and (or) long-term loading of the container. The results of the comparisons are indicators of the health of the plastic container during its operation.

Given the possible errors (up to 10%) dimensions external diameter of the cylindrical part of the cylinder associated with the design displacement of the container in the process of measurement, precision and crash sensors, etc. and the specific technology of manufacturing a plastic shell, the measured value of the increment of the external diameter of the cylindrical part of the container should not exceed permissible by more than 10%.

The task is solved in that the device for health monitoring of reinforced plastic cylinder having two heads and a Central cylindrical part, according to the invention soderjatelinii, mounted on the support with the ability to measure the increment of the external diameter of the cylindrical part of the plastic container.

The described device is mainly intended for large plastic containers for safe operation and transportation which requires special equipment.

In the present invention a device for monitoring the health of the container includes a support providing a stationary installation of the tank during feeding, which are conducted by measuring the increment of the external diameter of its cylindrical part.

In an advantageous variant implementation support contains extensive Foundation and installed on the base for movement along at least two of the fixing unit of plastic container, placed in the region of its cylindrical part.

According to one variant of the invention the fixing unit includes a frame, covering the plastic container along the perimeter of the supplied set against each other, at least two clamping devices movable in the radial direction, while the displacement sensors are mounted on the frame.

Fosmon in the radial direction, provide compensation for changes in the dimensions of plastic container, which is accompanied by cyclic loading plastic container at the gas station and the gas consumption of the consumer.

To ensure safe transportation for refueling and to the consumer, as well as the safe operation of the consumer large plastic container, it is advisable that the bearing was installed in the building that serves as a protective case for a plastic container, and the body is equipped with a device to capture handling mechanism.

Further, the invention will be disclosed in more detail with specific examples of its implementation with reference to the drawings, in which: Fig.1 depicts a metal cylinder high pressure, longitudinal section; Fig.2 - the scheme of reinforcement plastic shell; Fig. 3 is a diagram of a device for health monitoring of reinforced plastic tank; Fig.4 - the fixing unit of plastic container device of Fig.1; Fig.5 - plastic container in a protective case.

Primarily the invention relates to large plastic tanks large capacity (1.0 m3

The liner 4, as shown in Fig.2, may be made of welded and contain the Central part 6 in the form of longitudinal welded shells and two of the bottom part 7, is welded around the perimeter to the ring. The liner 4 can also be implemented in other ways, for example from a seamless tube rolling or crimping its ends, deep drawing blanks, United annular bead etc.

Power shell 5 is made by winding the liner 4 high strength fibrous material impregnated with a binder, such as epoxy resin. In Fig. 2 shows a diagram of the reinforcement force sheath of fibrous polymeric material including alternating spiral layers 8 and annular layers 9, shown respectively in solid and dashed lines. When this ring layers 9 are only on the Central cylindrical portion 6 of the surface of the liner 4 and the spiral layers 8 on the entire surface of the liner 4, with the exception of technological poles serving to secure the liner in the winding machine. For the applied polymer material and operational and geometric characteristics of the container VD: working pressure, capacity, size of the container and shaped bottoms.

In an advantageous variant of the invention the wall thickness of the liner 4 (Fig. 1) and force the plastic sheath 5 is selected from the condition that the main bearing element of the body of the container is a plastic shell 5, and the metal material of the liner 4 at an operating pressure may be in the region of elastic-plastic deformation. The liner 4 is sealed by the shell, and the strength characteristics of the tank, basically, provides an external plastic sheath 5.

The bottom part 2 of the plastic container is made with a large margin of safety than the Central part 3. In an advantageous variant implementation of the plastic container, the factor of safety bottom parts exceeds the factor of safety the Central part on 4-15%.

Improved strength characteristics of the bottom parts 2 plastic containers (in accordance with the above condition are provided by the strengthening of the plastic sheath 5 and/or liner 4 in the bottom parts of the cylinder compared to the Central part 3. With this aim when designing plastic container the factor of safety corps tank in llingua for cylinders. PB 10-115-96" shall be taken not less than 2.6 in relation to the working pressure, and in the bottom parts on 4-15% more, for example in the range from 2.7 to 3.0. Made when designing plastic cylinder load factor of safety for the bottom parts and the cylindrical part are taken into account when calculating the wall thickness of the plastic shell and metal liner with regard to the material strength of the walls. Thus the wall thickness of the bottom parts and the Central part of the plastic shell and metal liner is calculated by known computational models (A. N. Elpatyevsky In. A. Vasiliev. Strength of cylindrical shells made of reinforced materials. - M.: Mashinostroenie, 1972, page 74).

In Fig.1 shows a plastic cylinder 1 with reinforced bottom parts 2 by the increased thickness of the walls of the liner 4 in these parts.

Increase operational safety of plastic bottles is provided with the following method and device for health monitoring of reinforced plastic tank VD.

Mainly the proposed method and the device are designed for monitoring the health of large plastic containers, type cylinders made sagecover cylinder includes determining the technical condition of the plastic shell, which is measured by the increment value of the external diameter of the cylindrical part of the cylinder under the influence of internal pressure.

Health monitoring of reinforced plastic tank perform on the stage of its manufacture, acceptance testing and during operation, when the cyclic and (or) long-term loading of the container.

Thus the increment of the external diameter of the cylindrical part of the cylinder under the action of a certain internal pressure is measured during acceptance testing of the balloon is in the process of hydraulic and/or pneumatic tests under cyclic loading cylinder during each refueling and (or) under sustained loading in the period between refills.

Depending on the characteristics of manufacturing and operation of plastic bladder control can also be carried out on only one of these stages, for example during cyclic loading during each charging cylinder.

Because of the cylindrical part 3 of the plastic container in a generally monotonous and basementy (except zone edge effect) and moving all the points on the surface of the cylindrical part of the container is almost identical, the increment emergency reserve.

In an advantageous variant of the method in order to reduce measurement errors increment the external diameter of the cylindrical part of the container is measured in two planes equidistant from the transverse axis of the container and the outside edge effect. In plastic cylinders with welded metal liner 4, shown in Fig. 2, the zones of the edge effect will be the area of the weld seams 10, connecting the Central shell 6 of the liner with its bottoms 7. This increment of the external diameter of the cylindrical part of the container is measured in two planes equidistant from the transverse axis of the container between the weld seams 10, connecting the bottom part 7 of the liner 4 with its cowling 6.

Measured for a given internal pressure increment value of the external diameter of the cylindrical part of the cylinder is compared with the corresponding specified internal pressure preset allowable increment value of the external diameter and the comparison result is judged on the technical condition of the plastic shell and about the health of the bladder.

Given the possible errors of technology and measurements (usually taken within 10% of the outer diameter of the cylindrical part of balikov and measurement procedures, etc., it is accepted that the measured value of the increment of the external diameter of the cylindrical part of the container should not exceed permissible by more than 10%. The excess for a particular level of loading of the cylinder internal pressure measured value increment outer diameter permissible by more than 10% indicates a reduction factor of safety plastic container below an acceptable level (2,6), or disability plastic container.

When monitoring the health of plastic container on the stage of its manufacturing process of a pneumatic and/or hydraulic testing of the allowable increment value of the external diameter of the cylindrical part of the metal cylinder from a certain pressure determined by calculation on the basis of the known stress-strain state of cylindrical shells made of reinforced fibers (A. N. Elpatyevsky In. A. Vasiliev. Strength of cylindrical shells made of reinforced materials. - M. : Mashinostroenie, 1972).

For example, the authors found that plastic cylinder with a power envelope of the high modulus fiberglass (for example, the container DB-40) design of dopustimoy from the action of the working pressure is 0.7%. The increase in the increment of the external diameter of the cylindrical part of the container is less than 0.7% indicates normal operation of the tank.

For power shell made of other materials (e.g. carbon fiber, organoplastic) this value may slightly vary and depends on the module of material used and the thickness of the wall.

The calculated allowable increment value of the external diameter of the cylindrical part of the cylinder for a given internal pressure is compared with the value of the increment of the external diameter of the cylindrical part of the container, measured for the same pressure during pneumatic and/or hydraulic testing.

The excess of the measured values of estimated valid values more than 10% indicates that the factor of safety is made of plastic container below an acceptable level (2,6) or about the lack of health plastic container. In this case, plastic container or can in some cases be operated with a lower margin of safety (lower working pressure), or do not operate.

For plastic container held acceptance of these tests, the increment value of the external diameter of the cylindrical part of the cylinder for a given internal pressure is accepted as valid values, with which compare the values measured during operation of the cylinder: under cyclic loading - during each filling of the container and (or) in the period of the long loading between gas stations. In the period of loading measurements should preferably be carried out continuously or at least once a day. In this match increment value of the external diameter of the cylindrical part of the metal cylinder are measured under the same internal pressure.

The comparison results are an indicator of the health of a plastic cylinder, which define the conditions (or opportunity) further operation of the plastic container.

The excess of the measured value valid values more than 10% indicates that the safety factor operated plastic container below an acceptable level (2,6) or about the lack of health plastic container. In this case, the metal container must either be operated with a lower margin of safety (lower working pressure) or withdrawn from use.

To ensure safety during the loading cylinder pnevmoraspyleniem measurement priesley low pressures.

According to one of the options in the hydraulic test cylinder in the process of loading create the scale values of the increment of the external diameter at intervals of internal pressure. The magnitude of the internal pressure, which is measured allowable increment value of the external diameter and the measurement interval) to create a scale, choose from a condition of physical and mechanical properties of a plastic shell and liner (for example, the beginning of the plastic deformation of the material of the liner, the pressure level corresponding to the beginning of the cracking of the binder, and so on), and taking into account safety factors.

Respectively comparing the increment value of the outer diameter is measured during the loading of the gas environment during operation of the cylinder under the same internal pressure, and that for the valid values. Loading plastic cylinder gas medium is performed with the consideration of the characteristics of the technical condition of the container, obtained from measurements at lower values of internal pressure in accordance with the scale.

The proposed method is implemented by the device shown in Fig.4. The device comprises a support 11 for the plastic container 1, including n least two nodes 13 of the fixing metal cylinder 1.

Each node 13 of the fixing frame contains 14 covering plastic container 1 along the perimeter. Frame 14 (Fig.5) through slide 15 mounted on rails (not shown) of the base 12 can move along it. Each frame 14 is equipped with clamping devices 16, movable in the radial direction. The clamping device 16 is made, for example, in the form of spring links that have low stiffness in the radial direction.

Each clamping device 16 contains a spring-loaded heel 17, pressed against the plastic shell of the container 1. To provide a more secure fit in the support 11 on the cylinder 1 in places pressing Fri 17 through wound bandages 18 (Fig.1) made grooves. The clamping device 16 is connected to the frame 14 by bolts 19 through which is regulated by the degree of pressing the heel 17 to the cylinder 1. Bolts establish and regulate when testing the tank.

On the frame 14 of support 11 has two sensor 20 moves, such as sensor type indicator. In an advantageous embodiment, the device comprises an automatic control system 21, including the unit of measurement increment external diameter cylindrical and the alarm unit. Describes an automated system can be designed by well-known scheme adopted in the control and measuring equipment, on the basis of known components.

According to one variant of the invention bearing mounted in the housing 22 (Fig.5) that serves as a protective case for a plastic bottle and is made with the possibility of placing and fixing it controlled the composition of the container 1. The housing 22 is equipped with a device 23 for his capture handling mechanism. In addition, the housing 22 has a cover 24, which is closed by means of locks (not shown). On the housing 21, for example on the cover 24, is a window 25 for visual tracking readings automatic system 21 of the control.

Health monitoring of reinforced plastic tank during operation is performed as follows.

New plastic tank 1 is supplied to the consumer in a protective case 22. Further operation of the cylinder, including shipping it to the gas station and back to the consumer, is also carried out in a protective case. In the accompanying documentation to the cylinder indicated the scale of values of the increment of the external diameter of the cylindrical part of the container is imoe the value for the maximum working pressure. Valid values can be specified directly on the indicator displacement sensor or included in an automatic control system in the unit of comparison.

Valid values measured during acceptance testing of the plastic container 1. During operation of the cylinder each time the dressing sensors 20 (Fig. 4) or automated system 21, which includes the sensor 20 moves, measure the increment of the external diameter of the cylindrical part of the cylinder for a given internal pressure and compare it to the allowable.

When there is a valid scale values increase in internal pressure during filling of the container is provided with respect to the characteristics of the technical condition of the container, obtained from measurements at lower values of internal pressure in accordance with the scale.

In the period of the long loading plastic container, for example for more than a year, in the intervals between refills increment the external diameter of the cylindrical part of the cylinder for the working pressure is controlled continuously by an automated system 21.

Until measured during charging and (or) long loading cylinder increment value of the external diameter Qili the IU. When exceeding the specified value of the plastic container should be transferred to work with a reduced factor of safety (or low pressure), or withdrawn from use for more thorough examination.

The described method enables the operation period plastic container continuous monitoring of the technical condition of the plastic shell.

In conjunction with other known methods, for example by way of leakage monitoring of the working environment in patent RU 2117853 C1 , ensures reliable continuous monitoring of efficiency of plastic bottles to prevent accidents, which is especially important in the operation of large plastic bottles.

It should be noted that the invention is not limited to the described examples of preferred implementations and clear to the person skilled in the art modifications not beyond the scope of the invention defined by its formula.

Claims

1. Plastic cylinder high-pressure containing two bottom portion and located between the Central part, whereas the eat, the factor of safety bottom parts exceeds the factor of safety the Central part on 4-15%.

2. Plastic tank high pressure under item 1, characterized in that the body of the container is made from the condition that the factor of safety corps cylinder in the cylindrical Central part is 2.6 in relation to the value of the working pressure, and the bottom part is from 2.7 to 3.0.

3. Method of monitoring the health of the plastic container by measuring a specified parameter describing the technical condition of the container, characterized in that said parameter is the increment of the external diameter of the cylindrical part of the plastic container under the influence of internal pressure.

4. Method of monitoring the health of plastic container under item 3, characterized in that the increment of the external diameter of the cylindrical part of the container is measured at a loading cylinder for a given internal pressure and the measured value is compared with the corresponding specified internal pressure preset allowable increment value of the external diameter and the comparison result is judged on the performance of the balloon.

5. Fashion designers in the process of a pneumatic and/or hydraulic testing of the container.

6. Method of monitoring the health of plastic container under item 5, characterized in that the permissible value of the increment of the diameter of the cylinder are determined by calculation.

7. Method of monitoring the health of a plastic container according to any one of paragraphs. 3-6, characterized in that the control produced during operation under cyclic loading of a container at each refueling.

8. Method of monitoring the health of a plastic container according to any one of paragraphs. 3-6, characterized in that the control produced during operation under sustained loading plastic container.

9. Method of monitoring the health of plastic container under item 7 or 8, characterized in that the circular and (or) long-term loading of the container at a given internal pressure is measured increment of the external diameter of the cylindrical part of the container and the measured value is compared with the corresponding specified internal pressure preset allowable increment value of the external diameter and the comparison result is judged on the performance of the balloon.

10. Method of monitoring the health of plastic container under item 9, characterized in that the specified dopustimyh controlled container.

11. Method of monitoring the health of a plastic container according to any one of paragraphs. 3-10, wherein the increment value of the external diameter of the cylindrical part of the container is measured for the maximum working pressure.

12. Method of monitoring the health of a plastic container according to any one of paragraphs. 3-11, characterized in that when pressure testing will determine the scale of values of the increment of the external diameter of the cylindrical part of the container at the given values of the internal pressure, thus loading the pneumatic test or filling up the gas tank is performed with the consideration of the characteristics of the technical condition of the container, obtained from measurements at lower values of internal pressure in accordance with the scale.

13. Method of monitoring the health of a plastic container according to any one of paragraphs. 3-12, characterized in that the excess of the measured values of the increment of the external diameter of the cylindrical part of the container specified value by more than 10% characterizes the loss of efficiency of the container.

14. Method of monitoring the health of a plastic container according to any one of paragraphs. 3-13, characterized in that the increment of the external diameter of cylindri outside edge effect.

15. Device health monitoring, composite container, comprising two bottom parts and the Central cylindrical part, where the device contains a sensor measuring a given parameter, describing the technical condition of the container, characterized in that it comprises a support configured to hold plastic container and at least one displacement transducer, mounted on a support with the ability to measure the increment of the external diameter of the cylindrical part of the plastic container.

16. The device according to p. 15, wherein the bearing includes an extended base and mounted on the base for movement along its length, at least two of the fixing unit of plastic container, each of the fixing unit contains at least one displacement sensor.

17. The device under item 15 or 16, characterized in that the nodes commit placed in the region of the cylindrical part of the plastic container.

18. Device according to any one of paragraphs. 15-17, wherein the fixing unit includes a frame, covering the plastic container along the perimeter of the supplied set against each other, at least two of the frame.

19. Device according to any one of paragraphs. 15-18, characterized in that the bearing is installed in the housing that serves as a protective case for a plastic bottle and is made with the possibility of placing and fixing it controlled plastic container, the body is equipped with a device to capture handling mechanism.