CN111841449A - Method of experimental equipment for discharging polyethylene slurry - Google Patents

Abstract

The invention relates to experimental equipment for discharging polyethylene slurry, which comprises: a polymerization reaction kettle for storing polyethylene slurry; the discharge tank is connected with the polymerization reaction kettle through a feed pipe, and a first valve is arranged on the feed pipe; the discharge tank is connected with the flash tank through a discharge pipe, and a second valve is arranged on the discharge pipe; wherein, one end of the feeding pipe and one end of the discharging pipe, which are far away from the polymerization reaction kettle, both extend downwards in an inclined way; when the first valve is opened, the polymerization reaction kettle conveys polyethylene slurry to the discharge tank under the action of pressure difference or/and liquid level difference; when the second valve is opened, the discharge tank conveys polyethylene slurry into the flash tank under the action of pressure difference or/and liquid level difference. According to the invention, the discharge tank is arranged between the first valve and the second valve, and the liquid filling and draining circulation operation is carried out on the discharge tank by switching the on-off of the first valve and the second valve, so that the continuous discharge of the slurry in the reaction kettle can be realized.

Description

A method of experimental equipment for discharging polyethylene slurry

technical field

The invention relates to the technical field of polyethylene, in particular to experimental equipment and a method for discharging polyethylene reactor slurry of a polyethylene continuous reaction test device.

Background technique

The test device is mainly responsible for the development of high-end product technology, and the development of a series of frontier fields such as catalyst research and development, and the equipment to improve the progress of research and development. Usually, the operating conditions of the test device (such as temperature, pressure, process, liquid level, etc.) should be matched with the production device, but due to its particularity (such as a proportional reduction in flow), some instrumentation equipment cannot be selected or Therefore, some new control modes and methods need to be developed.

The polyethylene reactor slurry discharge equipment of the polyethylene continuous reaction device. The polyethylene reactor slurry contains about 30% (mass fraction) of polyethylene powder, and the particle diameter distribution is 100-500μm, accounting for 85%. If the test device adopts industrial production The discharge method in the device is controlled. In order to prevent the solid particles in the slurry from settling, a certain flow rate needs to be met, which leads to a relatively small pipe diameter, which is about 10mm, which makes it impossible to select the discharge valve; For conventional control valves, when the slurry passes through the narrow slit between the valve seat and the valve core, the large particles and flocs in the slurry may get stuck in the channel, and the solid particles accumulate more and more, thereby blocking the entire valve. , causing the material in the kettle to be unable to be discharged, resulting in an accident.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is the deficiency of the prior art, and a kind of experimental equipment and method for discharging polyethylene slurry is provided.

The technical scheme that the present invention solves the above-mentioned technical problems is as follows: a kind of experimental equipment for discharging polyethylene slurry, comprising:

Polymerization reactors for storing polyethylene slurries;

a discharge tank, the discharge tank is connected with the polymerization reactor through a feed pipe, and a first valve is installed on the feed pipe;

a flash tank, the discharge tank is connected to the flash tank through a discharge pipe, and a second valve is installed on the discharge pipe;

Wherein, the ends of the feed pipe and the discharge pipe away from the polymerization reactor are inclined downward; when the first valve is opened, the polymerization reactor is under the action of the pressure difference or/and the liquid level difference. The polyethylene slurry is transported into the discharge tank; when the second valve is opened, the discharge tank transports the polyethylene slurry into the flash tank under the action of pressure difference or/and liquid level difference.

The beneficial effects of the present invention are as follows: in the present invention, a discharge tank is arranged between the first valve and the second valve, and the discharge tank is filled and drained by switching the on-off of the first valve and the second valve to perform a liquid-filling and liquid-draining cycle operation, The slurry in the reactor can be continuously discharged.

On the basis of the above technical solutions, the present invention can also be improved as follows.

Further, the discharge tank is arranged vertically, the two ends of the feed pipe are respectively connected with the lower part of the polymerization reactor and the bottom of the discharge tank, and the two ends of the discharge pipe are respectively connected with the bottom of the discharge tank. It is communicated with the flash tank, and the top of the discharge tank is communicated with the top of the polymerization reactor through an exhaust pipe, and a third valve is installed on the exhaust pipe.

The beneficial effect of adopting the above-mentioned further scheme is: using the third valve to make the gas phase part of the discharge tank communicate with the gas phase part of the polymerization reactor.

Further, the third valve is a pneumatic ball valve or an electric ball valve.

The beneficial effect of adopting the above-mentioned further scheme is that the shut-off/connection operation can be realized by the electric ball valve or the pneumatic ball valve.

Further, the discharge tank is arranged obliquely, the two ends of the feed pipe are respectively communicated with the lower part of the polymerization reactor and the upper end of the discharge tank, and the two ends of the discharge pipe are respectively connected with the lower end of the discharge tank and the upper end of the discharge tank. The flash tank is in communication.

The beneficial effect of adopting the above-mentioned further scheme is that: the discharge tank is inclined and arranged, and the discharge tank is equivalent to a part in the middle of the feed pipe and the discharge pipe, and no other valves are required, so that the continuous discharge of the polymerization reactor can be achieved, which simplifies the process.

Further, the central axis of the discharging tank, the central axis of the feeding pipe and the central axis of the discharging pipe are coincident.

The beneficial effect of adopting the above-mentioned further scheme is that the discharging tank, the feeding pipe and the discharging pipe are equivalent to a whole to realize continuous discharging.

Further, the discharge pipe is communicated with the middle of the flash tank.

Further, the first valve and the second valve are respectively large-diameter ball valves.

The beneficial effect of adopting the above-mentioned further scheme is that: the large-diameter ball valve is used to make the slurry in the pipeline rely on gravity to flow from the flow channel in the subsequent process, which can effectively prevent the solid particles in the slurry from settling and cause pipeline blockage, and ensure the smoothness of the pipeline.

Further, the first valve and the second valve are respectively a pneumatic ball valve or an electric ball valve.

The beneficial effect of adopting the above-mentioned further scheme is that the shut-off/connection operation can be realized by the electric ball valve or the pneumatic ball valve.

Further, the feed pipe is connected with the pipeline at the discharge port of the polymerization reactor through a flange, and the discharge pipe is connected with the pipeline at the feed port of the flash tank through a flange.

The beneficial effect of adopting the above-mentioned further scheme is that the flange is used for connection, which is convenient for disassembly.

Further, the inner diameter of the discharge tank is the same as the inner diameter of the feed pipe or/and the discharge pipe.

The beneficial effect of adopting the above-mentioned further scheme is: the inner diameter of the discharge tank is the same as the inner diameter of the feed pipe and/or the discharge pipe, so that the discharge tank is equivalent to a part of the feed pipe or the discharge pipe, and even the feed pipe, the discharge pipe can be The material pipe and the discharge tank are regarded as a whole, and the valve is switched on and off. The slurry flows to the subsequent process by gravity, and the discharge tank is filled/drained to achieve the continuous discharge of the polymerization reactor, which simplifies the process. , to ensure the smoothness of the entire pipeline.

A continuous discharging method of polyethylene slurry, which is realized by the above-mentioned experimental equipment, comprises the following steps:

S1, open the first valve, and the polymerization reactor transports polyethylene slurry into the discharge tank until the pressure difference or/and the liquid level difference in the discharge tank is the same as the polymerization reactor;

S2, close the first valve, open the second valve, and the discharge tank transports polyethylene slurry to the flash tank;

S3, when the polyethylene slurry in the discharge tank is completely transported into the flash tank, close the second valve.

Description of drawings

1 is a schematic structural diagram of an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of another embodiment of the present invention.

In the accompanying drawings, the list of components represented by each number is as follows:

1. Polymerization reactor; 2. Discharging tank; 21. Feeding pipe; 22. Discharging pipe; 23. Flange; 24. Exhaust pipe; 3. Flash tank; 4. First valve; 5. First valve The second valve; 6, the third valve.

Detailed ways

The principles and features of the present invention will be described below with reference to the accompanying drawings. The examples are only used to explain the present invention, but not to limit the scope of the present invention.

Example 1

As shown in Figure 1, a kind of experimental equipment for discharging polyethylene slurry of the present embodiment includes:

Polymerization reactor 1 for storing polyethylene slurry;

The discharge tank 2, the discharge tank 2 is connected with the polymerization reactor 1 through a feed pipe 21, and a first valve 4 is installed on the feed pipe 21;

Flash tank 3, the discharge tank 2 is connected with the flash tank 3 through a discharge pipe 22, and a second valve 5 is installed on the discharge pipe 22;

Wherein, the ends of the feed pipe 21 and the discharge pipe 22 away from the polymerization reactor 1 both extend downwards obliquely; when the first valve 4 is opened, the polymerization reactor 1 is in a pressure difference or/and liquid The polyethylene slurry is transported into the discharge tank 2 under the action of the head difference; when the second valve 5 is opened, the discharge tank 2 flashes to the discharge tank 2 under the action of the pressure difference or/and the liquid level difference The polyethylene slurry is transported in the tank 3.

In this embodiment, a discharge tank is arranged between the first valve and the second valve, and the discharge tank is filled and drained by switching the on-off of the first valve and the second valve, so that the slurry in the reactor can be realized. Continuous discharge.

Specifically, as shown in FIG. 1 , the discharge tank 2 is arranged vertically, and the two ends of the feed pipe 21 are respectively connected with the lower part of the polymerization reaction kettle 1 and the bottom of the discharge tank 2 . Both ends of the pipe 22 are communicated with the bottom of the discharge tank 2 and the flash tank 3 respectively, and the top of the discharge tank 2 is communicated with the top of the polymerization reactor 1 through an exhaust pipe 24. The exhaust pipe A third valve 6 is mounted on 24 . A third valve is used to communicate the gas phase portion of the draw tank with the gas phase portion of the polymerization kettle.

Wherein, the third valve 6 is a pneumatic ball valve or an electric ball valve. The cut-off/connection operation can be realized by electric ball valve or pneumatic ball valve.

A specific solution of this embodiment is that the discharge pipe 22 communicates with the middle of the flash tank 3 .

A specific solution of this embodiment is that the first valve 4 and the second valve 5 are respectively large-diameter ball valves, and a large-diameter ball valve is used to allow the slurry in the pipeline to flow to the subsequent process by gravity, which can effectively prevent the slurry from being trapped in the slurry. The solid particles settle and cause pipeline blockage to ensure the smoothness of the pipeline. The first valve 4 and the second valve 5 are respectively a pneumatic ball valve or an electric ball valve, and both the electric ball valve or the pneumatic ball valve can realize the cut-off/connection operation.

A preferred solution of this embodiment is that, as shown in FIG. 1 , the feed pipe 21 is connected to the pipe at the discharge port of the polymerization reactor 1 through a flange 23 , and the discharge pipe 22 is connected to the The pipeline at the feed inlet of the flash tank 3 is connected through the flange 23 , and the exhaust pipe 24 is connected with the pipeline at the inlet of the polymerization reactor 1 through the flange 23 . The flange is used for connection, which is convenient for disassembly.

A preferred solution of this embodiment is that the inner diameter of the discharge tank 2 is the same as the inner diameter of the feed pipe 21 or/and the discharge pipe 22 . The inner diameter of the discharge tank is the same as the inner diameter of the feed pipe and/or discharge pipe, so that the discharge tank is equivalent to a part of the feed pipe or discharge pipe, and even the feed pipe, discharge pipe and discharge tank can be regarded as As a whole, the valve is switched on and off, the slurry flows to the subsequent process by gravity, and the discharge tank is filled/drained to achieve continuous discharge of the polymerization reactor, simplifying the process and ensuring the smoothness of the entire pipeline. .

Specifically, the discharge tank in this embodiment adopts a slender structure. When the first valve 4 and the second valve 5 are opened, the slurry can completely enter the discharge tank 2 without clogging.

The first valve, the second valve and the third valve in this embodiment can be manual valves or solenoid valves. When solenoid valves are selected, a time controller can be used to connect them to control the on-off time of the solenoid valves. Control the switching between the first valve, the second valve and the third valve; when a manual valve is used, the discharge time can be manually selected. Whether a manual valve or a solenoid valve is used, intermittent volume discharge can be realized, so as to achieve continuous discharge. the purpose of the material.

This embodiment is used for the discharge of polyethylene slurry by the slurry method. (1) When the polymerization reactor is discharged, the first valve and the third valve are opened, and the second valve is closed, and the polyethylene slurry in the polymerization reactor is polymerized. The flange and the first valve at the outlet pipeline of the reactor flow into the discharge tank from the bottom, and the gas phase in the polymerization reactor enters the discharge tank from the top through the third valve and the flange at the inlet of the polymerization reactor After a period of time, the pressure and liquid level of the discharge tank reach equilibrium with the polymerization reactor, close the first valve and the third valve, and this process completes the discharge of the polymerization reactor and the feeding of the discharge tank. (2) When the discharge tank is discharging, open the second valve, close the first valve and the third valve, due to the pressure difference and liquid level difference between the discharge tank and the flash tank, when the second valve is opened, the discharge tank The slurry inside flows into the flash tank from the bottom through the second valve and the flange on the pipeline at the inlet of the flash tank. After a period of time, all the slurry in the discharge tank flows into the flash tank, and the third tank is closed. Valve, this process completes the discharge process of the discharge tank. Such circulating operation achieves the effect of continuous discharging of the polymerization reactor.

Example 2

As shown in Figure 2, a kind of experimental equipment for discharging polyethylene slurry of the present embodiment includes:

Polymerization reactor 1 for storing polyethylene slurry;

The discharge tank 2, the discharge tank 2 is connected with the polymerization reactor 1 through a feed pipe 21, and a first valve 4 is installed on the feed pipe 21;

Flash tank 3, the discharge tank 2 is connected with the flash tank 3 through a discharge pipe 22, and a second valve 5 is installed on the discharge pipe 22;

Wherein, the ends of the feed pipe 21 and the discharge pipe 22 away from the polymerization reactor 1 both extend downwards obliquely; when the first valve 4 is opened, the polymerization reactor 1 is in a pressure difference or/and liquid The polyethylene slurry is transported into the discharge tank 2 under the action of the head difference; when the second valve 5 is opened, the discharge tank 2 flashes to the discharge tank 2 under the action of the pressure difference or/and the liquid level difference The polyethylene slurry is transported in the tank 3.

In this embodiment, a discharge tank is arranged between the first valve and the second valve, and the discharge tank is filled and drained by switching the on-off of the first valve and the second valve, so that the slurry in the reactor can be realized. Continuous discharge.

Specifically, as shown in FIG. 2 , the discharge tank 2 is arranged obliquely, and both ends of the feed pipe 21 are connected with the lower part of the polymerization reactor 1 and the upper end of the discharge tank 2 respectively. Both ends of 22 are respectively communicated with the lower end of the discharge tank 2 and the flash tank 3 . The discharge tank is arranged inclined, and the discharge tank is equivalent to the middle part of the feed pipe and the discharge pipe. No need to set other valves, the continuous discharge of the polymerization reactor can be achieved, which simplifies the process.

A preferred solution of this embodiment is that the central axis of the discharge tank 2 , the central axis of the feed pipe 21 and the central axis of the discharge pipe 22 are coincident. The discharge tank, the feed pipe and the discharge pipe are equivalent to a whole to realize continuous discharge.

As shown in FIG. 1 , the discharge pipe 22 communicates with the middle of the flash tank 3 .

A specific solution of this embodiment is that the first valve 4 and the second valve 5 are respectively large-diameter ball valves, and a large-diameter ball valve is used, so that the slurry in the pipeline relies on gravity to flow from the flow channel in the subsequent process, which can effectively prevent the slurry from being trapped in the slurry. The solid particles settle and cause pipeline blockage to ensure the smoothness of the pipeline.

The first valve 4 and the second valve 5 in this embodiment are respectively a pneumatic ball valve or an electric ball valve. The cut-off/connection operation can be realized by electric ball valve or pneumatic ball valve.

Specifically, as shown in FIG. 2 , the feed pipe 21 is connected to the pipeline at the discharge port of the polymerization reactor 1 through a flange 23 , and the discharge pipe 22 is fed with the flash tank 3 The pipeline at the mouth is connected by flange 23 . The flange is used for connection, which is convenient for disassembly.

A preferred solution of this embodiment is that the inner diameter of the discharge tank 2 is the same as the inner diameter of the feed pipe 21 or/and the discharge pipe 22 . The inner diameter of the discharge tank is the same as the inner diameter of the feed pipe and/or discharge pipe, so that the discharge tank is equivalent to a part of the feed pipe or discharge pipe, and even the feed pipe, discharge pipe and discharge tank can be regarded as As a whole, the valve is switched on and off, the slurry flows to the subsequent process by gravity, and the discharge tank is filled/drained to achieve continuous discharge of the polymerization reactor, simplifying the process and ensuring the smoothness of the entire pipeline. .

Specifically, the discharge tank in this embodiment adopts a slender structure. When the first valve 4 and the second valve 5 are opened, the slurry can completely enter the discharge tank 2 without clogging.

The first valve, the second valve and the third valve in this embodiment can be manual valves or solenoid valves. When solenoid valves are selected, a time controller can be used to connect them to control the on-off time of the solenoid valves. Control the switching between the first valve, the second valve and the third valve; when a manual valve is used, the discharge time can be manually selected. Whether a manual valve or a solenoid valve is used, intermittent volume discharge can be realized, so as to achieve continuous discharge. the purpose of the material.

This embodiment is used for the discharging of polyethylene slurry by the slurry method. (1) When discharging from the polymerization reactor, open the first valve and close the second valve, and the polyethylene slurry in the polymerization reactor is discharged through the polymerization reactor. The flange and the first valve at the outlet pipeline flow into the discharge tank from the bottom. After a period of time, the slurry fills the discharge tank, and the first valve is closed. This process completes the discharge of the polymerization reactor and the feeding of the discharge tank. material. (2) When the discharge tank is discharging, open the second valve and close the first valve. Due to the liquid level difference between the discharge tank and the flash tank, when the second valve is opened, the slurry in the discharge tank passes through the first valve from the bottom. The second valve and the flange on the pipeline at the inlet of the flash tank flow into the flash tank. After a period of time, all the slurry in the discharge tank flows into the flash tank, close the second valve, and the process is completed. The discharge process of the material tank. Such circulating operation achieves the effect of continuous discharging of the polymerization reactor.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", " Rear, Left, Right, Vertical, Horizontal, Top, Bottom, Inner, Outer, Clockwise, Counterclockwise, Axial, The orientations or positional relationships indicated by "radial direction", "circumferential direction", etc. are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the indicated devices or elements. It must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation of the present invention.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined.

In the present invention, unless otherwise expressly specified and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection , or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between the two elements, unless otherwise specified limit. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

In the present invention, unless otherwise expressly specified and limited, a first feature "on" or "under" a second feature may be in direct contact between the first and second features, or the first and second features indirectly through an intermediary touch. Also, the first feature being "above", "over" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower level than the second feature.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples, without conflicting each other.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Embodiments are subject to variations, modifications, substitutions and variations.

Claims (10)

1. An experimental facility for polyethylene slurry discharge, comprising:

a polymerization reaction kettle for storing polyethylene slurry;

the discharge tank is connected with the polymerization reaction kettle through a feed pipe, and a first valve is arranged on the feed pipe;

the discharge tank is connected with the flash tank through a discharge pipe, and a second valve is arranged on the discharge pipe;

wherein, one end of the feeding pipe and one end of the discharging pipe, which are far away from the polymerization reaction kettle, both extend downwards in an inclined way; when the first valve is opened, the polymerization reaction kettle conveys polyethylene slurry to the discharge tank under the action of pressure difference or/and liquid level difference; when the second valve is opened, the discharge tank conveys polyethylene slurry into the flash tank under the action of pressure difference or/and liquid level difference.

2. The experimental facility for discharging polyethylene slurry according to claim 1, wherein the discharge tank is vertically arranged, two ends of the feeding pipe are respectively communicated with the lower part of the polymerization reaction kettle and the bottom of the discharge tank, two ends of the discharging pipe are respectively communicated with the bottom of the discharge tank and the flash tank, the top of the discharge tank is communicated with the top of the polymerization reaction kettle through an exhaust pipe, and a third valve is installed on the exhaust pipe.

3. The experimental facility for discharging polyethylene slurry according to claim 2, wherein the third valve is a pneumatic ball valve or an electric ball valve.

4. The experimental facility for discharging polyethylene slurry according to claim 1, wherein the discharge tank is arranged obliquely, two ends of the feeding pipe are respectively communicated with the lower part of the polymerization reaction kettle and the upper end of the discharge tank, and two ends of the discharging pipe are respectively communicated with the lower end of the discharge tank and the flash tank.

5. The experimental facility for the discharge of polyethylene slurry according to claim 4, wherein the central axis of the discharge tank, the central axis of the feeding pipe and the central axis of the discharge pipe coincide; the discharge pipe is communicated with the middle part of the flash tank.

6. The experimental facility for discharging polyethylene slurry according to claim 1, wherein the first valve and the second valve are large-diameter ball valves respectively.

7. The experimental facility for discharging polyethylene slurry according to claim 1, wherein the first valve and the second valve are respectively a pneumatic ball valve or an electric ball valve.

8. The experimental facility for discharging polyethylene slurry according to claim 1, wherein the feeding pipe is connected with the pipeline at the discharging port of the polymerization reaction kettle through a flange, and the discharging pipe is connected with the pipeline at the feeding port of the flash tank through a flange.

9. The experimental facility for discharging polyethylene slurry according to claim 1, wherein the discharge tank inner diameter is the same as the feed pipe or/and the discharge pipe inner diameter.

10. A continuous discharge process of polyethylene slurry, characterized by the fact that it is carried out with the experimental equipment according to any of claims 1 to 9, comprising the following steps:

s1, opening the first valve, and conveying the polyethylene slurry to the discharge tank by the polymerization reaction kettle until the pressure difference or/and the liquid level difference in the discharge tank is the same as the polymerization reaction kettle;

s2, closing the first valve, opening the second valve, and conveying polyethylene slurry to the flash tank by the discharge tank;

and S3, when the polyethylene slurry in the discharge tank is completely conveyed into the flash tank, closing the second valve.

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