Alkali liquor and organic gas recovery device in calcium carbide method PVC (polyvinyl chloride) production

Abstract

The utility model relates to an alkali liquor and organic gas recovery device in calcium carbide method polyvinyl chloride (PVC) production, which comprises a recovery gas buffer tank, a vacuum pump, an on-line oxygen analyzer, a cooler, a stripping tower, a distillation still and a waste alkali buffer tank, a first outlet pipeline of the vacuum pump is communicated with the recovery gas buffer tank, and a first inlet pipeline of the vacuum pump is communicated with the cooler. A first inlet pipeline is communicated with an emptying pipeline of the recovered gas buffer tank, a first outlet pipeline of the vacuum pump is provided with an online oxygen analyzer, a top exhaust pipeline of the stripping tower is communicated with the vacuum pump, the bottom of the stripping tower is provided with a distillation kettle, and a second outlet pipeline of the distillation kettle is communicated with a waste alkali buffer tank. Through the structure, the problems that in an existing technological process for producing PVC through a calcium carbide method, in the discharging process of waste alkali liquid, dissolved VCM and acetylene gas generate system fluctuation during recovery and effective utilization, a vacuum pump inlet leaks, atmosphere enters a production system, the oxygen content exceeds the standard, an explosive mixture is formed, and the risk of explosion ignition exists are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of alkali liquor and organic gas recovery and utilization, in particular to an alkali liquor and organic gas recovery device in the production of PVC by calcium carbide process. Background Art

[0002] Polyvinyl chloride, abbreviated as PVC (Polyvinyl chloride) in English, is a polymer formed by the polymerization of vinyl chloride monomer (VCM) in the presence of initiators such as peroxides and azo compounds, or by the free radical polymerization mechanism under the action of light or heat. Vinyl chloride homopolymers and vinyl chloride copolymers are collectively referred to as vinyl chloride resins.

[0003] PVC is an amorphous white powder with a small degree of branching, a relative density of about 1.4, a glass transition temperature of 77-90°C, and begins to decompose at around 170°C. It has poor stability to light and heat. At temperatures above 100°C or after prolonged exposure to sunlight, it will decompose to produce hydrogen chloride, and further autocatalytically decompose, causing discoloration and a rapid decline in physical and mechanical properties. In practical applications, stabilizers must be added to improve stability to heat and light.

[0004] PVC was once the world's most produced general-purpose plastic, and it is widely used in building materials, industrial products, daily necessities, floor coverings, floor tiles, artificial leather, pipes, wires and cables, packaging films, bottles, foaming materials, sealing materials, fibers, etc.

[0005] The calcium carbide production process is to use calcium carbide calcium carbide to react with water to generate acetylene, then use acetylene and hydrogen oxide to react to synthesize vinyl chloride monomer, and then polymerize it to generate PVC. The calcium carbide method has a lower production cost, so it is widely used.

[0006] In the existing process of producing PVC by the calcium carbide method, the waste alkali liquid causes system fluctuations during the recovery and effective utilization of dissolved VCM and acetylene gas during the discharge process, and leakage occurs at the vacuum pump inlet, allowing the atmosphere to enter the production system, causing the oxygen content to exceed the standard and forming an explosive mixture, posing the risk of explosion and fire. Utility Model Content

[0007] The utility model provides an alkali solution and organic gas recovery device in the production of PVC by the calcium carbide method, which solves the problem that in the existing process flow of producing PVC by the calcium carbide method, waste alkali solution causes system fluctuations when dissolved VCM and acetylene gas are recovered and effectively utilized during the discharge process, the vacuum pump inlet leaks, and the atmosphere enters the production system, causing the oxygen content to exceed the standard, forming an explosive mixture, and posing the risk of explosion and fire.

[0008] The technical solution of the utility model to solve the above technical problems is as follows:

[0009] The first outlet pipeline of the vacuum pump is connected to the recovery gas buffer tank, the first inlet pipeline of the vacuum pump is connected to the cooler, the first inlet pipeline of the vacuum pump is connected to the vent pipeline of the recovery gas buffer tank, an online oxygen analyzer is installed on the first outlet pipeline of the vacuum pump, the top exhaust pipeline of the stripping tower is connected to the vacuum pump, a distillation kettle is installed at the bottom of the stripping tower, and the second outlet pipeline of the distillation kettle is connected to the waste alkali buffer tank.

[0010] The beneficial effects of the utility model are as follows: through the online oxygen analyzer arranged on the vacuum pump, the online oxygen analyzer is interlocked with the arrangement on the recovery pipeline and the venting pipeline on the recovery gas buffer tank, and the recovery pipeline is the pipeline before the compressor. When the online oxygen analyzer detects that the oxygen content exceeds the standard, the cut-off valve before the compressor is closed, and the venting cut-off valve at the top of the recovery gas buffer tank is opened to vent, so as to ensure the smooth and safe operation of the recovery system.

[0011] On the basis of the above technical solution, the present invention can also be improved as follows.

[0012] Furthermore, a recovery valve, a pressure gauge and a pressure valve are installed on the exhaust pipeline of the stripping tower.

[0013] The beneficial effect of adopting the above further scheme is that the stripping tower is filled with fillers, and the waste alkali liquid enters the distillation kettle from top to bottom through the filler layer. The pressure gauge and pressure valve can detect and control the waste alkali liquid entering the cooler from the stripping tower, and the recovery valve controls the waste alkali liquid from the cooler to flow back to the stripping tower.

[0014] On the basis of the above technical solution, the present invention can also be improved as follows.

[0015] Furthermore, the distillation kettle has a hot water inlet pipeline and a hot water return pipeline. The hot water inlet pipeline is equipped with a second regulating valve front valve, a second regulating valve and a second regulating valve rear valve. The hot water return pipeline is equipped with a second return valve and a first liquid level meter.

[0016] The beneficial effect of adopting the above further scheme is that the waste alkali liquid enters the distillation kettle from top to bottom through the packing layer. When a certain liquid level is reached in the distillation kettle, the gas recovery valve at the top of the stripping tower is opened, the second regulating valve of the hot water inlet pipeline of the shell side of the distillation kettle and the second hot water return valve are opened, and the distillation kettle is slowly heated. When a certain temperature is reached, the VCM gas is cooled by a cooler.

[0017] On the basis of the above technical solution, the present invention can also be improved as follows.

[0018] Furthermore, the first liquid level meter is an on-site liquid level meter.

[0019] The beneficial effect of adopting the above further scheme is that the first liquid level meter is an on-site liquid level meter, which can observe the liquid level height in the distillation kettle on-site, making it convenient for the staff to operate the subsequent work.

[0020] On the basis of the above technical solution, the present invention can also be improved as follows.

[0021] Furthermore, the distillation kettle also has a second outlet pipeline, on which an alkali solution outlet valve, a third regulating valve front valve, a third regulating valve and a third regulating valve rear valve are installed.

[0022] The beneficial effect of adopting the above further scheme is that the second outlet pipeline is connected to the waste alkali buffer tank. When the online oxygen analyzer detects that the oxygen content in the vacuum pump exceeds the standard, the heated waste alkali liquid enters the waste alkali buffer tank through the alkali liquid outlet valve at the bottom of the distillation kettle and the third regulating valve.

[0023] On the basis of the above technical solution, the present invention can also be improved as follows.

[0024] Furthermore, the distillation kettle is also equipped with a second liquid level gauge and a second thermometer, and the second liquid level gauge has a top valve and a bottom valve.

[0025] The beneficial effect of adopting the above further solution is that the second thermometer installed on the still can check the temperature of the waste alkali liquid in the still. The second liquid level meter is remotely observed to check the liquid level of the waste alkali liquid in the still. Then, the liquid level of the waste alkali liquid in the still can be remotely controlled through the top valve and the bottom valve.

[0026] On the basis of the above technical solution, the present invention can also be improved as follows.

[0027] Furthermore, the second liquid level gauge is a remote liquid level gauge.

[0028] The beneficial effect of adopting the above further solution is that the liquid level of the waste alkali solution in the distillation kettle can be remotely checked through the second liquid level meter, making the operator's work more flexible and convenient for remote observation and remote control.

[0029] On the basis of the above technical solution, the present invention can also be improved as follows.

[0030] Furthermore, a vacuum pump is fixedly installed at the gas phase outlet of the cooler, and a cooling water inlet pipeline and a cooling water return pipeline are installed on the cooler. The cooling water inlet pipeline is equipped with a first regulating valve front valve, a first regulating valve and a first regulating valve rear valve, the cooling water return pipeline is equipped with a first return valve, and a first thermometer is also installed at the outlet of the cooler.

[0031] The beneficial effect of adopting the above further scheme is that a first thermometer is fixedly installed at the outlet of the cooler, the shell side is cooling water, and the VCM and acetylene gas temperatures at the outlet of the cooler are controlled by the first regulating valve front valve, the first regulating valve and the first regulating valve rear valve on the cooling water inlet pipeline, and the first regulating valve and the first thermometer are automatically controlled and regulated.

[0032] On the basis of the above technical solution, the present invention can also be improved as follows.

[0033] Furthermore, a drain pipeline is fixedly installed at the bottom of the recovery gas buffer tank, and a sewage hand valve is installed on the drain pipeline. A recovery pipeline and a venting pipeline are installed on the top of the recovery gas buffer tank. The recovery pipeline is installed with a first interlock cut-off valve rear valve, a first interlock cut-off valve and a first interlock cut-off valve front valve, and the venting pipeline is installed with a second interlock cut-off valve, a second interlock cut-off valve rear valve and a flame arrester.

[0034] The beneficial effect of adopting the above further scheme is that through the online oxygen analyzer arranged on the vacuum pump, the online oxygen analyzer and the first interlock cut-off valve rear valve, the first interlock cut-off valve and the first interlock cut-off valve front valve on the recovery gas buffer tank, the second interlock cut-off valve and the second interlock cut-off valve rear valve installed on the vent pipeline are arranged to be interlocked. When the online oxygen analyzer detects that the oxygen content exceeds the standard, the first interlock cut-off valve rear valve, the first interlock cut-off valve and the first interlock cut-off valve front valve are closed, and the second interlock cut-off valve and the second interlock cut-off valve rear valve on the top of the recovery gas buffer tank are opened to vent. At the same time, the flame arrester can prevent the leaked oxygen from burning to ensure the smooth and safe operation of the recovery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The utility model is a schematic diagram of the structure of an alkali solution and organic gas recovery device in the production of PVC by the calcium carbide process.

[0036] In the attached drawings, the parts represented by the reference numerals are as follows: 1-rear valve of the first interlock cut-off valve; 2-first interlock cut-off valve; 3-front valve of the first interlock cut-off valve; 4-recovery pipeline; 5-venting pipeline; 6-second interlock cut-off valve; 7-rear valve of the second interlock cut-off valve; 8-flame arrester; 9-recovery gas buffer tank; 10-online oxygen analyzer; 11-hand sewage valve; 12-first outlet pipeline; 13-first inlet pipeline; 14-vacuum pump; 15-front valve of the second regulating valve; 16-second regulating valve; 17-rear valve of the second regulating valve; 18-hot water inlet pipeline; 19-second return valve; 20- Hot water return pipeline; 21-pressure gauge; 22-pressure valve; 23-stripping tower; 24-distillation kettle; 25-first liquid level gauge; 26-top valve; 27-bottom valve; 28-second thermometer; 29-second liquid level gauge; 30-alkali solution outlet valve; 31-front valve of the third regulating valve; 32-third regulating valve; 33-rear valve of the third regulating valve; 34-second outlet pipeline; 35-cooler; 36-first thermometer; 37-front valve of the first regulating valve; 38-first regulating valve; 39-rear valve of the first regulating valve; 40-first return valve; 41-recovery valve; 42-waste alkali buffer tank. DETAILED DESCRIPTION

[0037] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0038] Example 1

[0039] like Figure 1 As shown, the first outlet pipeline 12 of the vacuum pump 14 is connected to the recovery gas buffer tank 9, the first inlet pipeline 13 of the vacuum pump 14 is connected to the cooler 35, the first inlet pipeline 13 of the vacuum pump 14 is connected to the venting pipeline 5 of the recovery gas buffer tank 9, an online oxygen analyzer 10 is installed on the first outlet pipeline 12 of the vacuum pump, the top exhaust pipeline of the stripping tower 23 is connected to the vacuum pump 14, the bottom of the stripping tower 23 is installed with a distillation kettle 24, and the second outlet pipeline 34 of the distillation kettle 24 is connected to the waste alkali buffer tank 42.

[0040] Specifically, through the online oxygen analyzer 10 arranged on the vacuum pump 14, the online oxygen analyzer 10 is interlocked with the settings on the recovery pipeline 4 and the venting pipeline 5 on the recovery gas buffer tank 9, and the recovery pipeline 4 is a pipeline before the compressor. When the online oxygen analyzer 10 detects that the oxygen content exceeds the standard, in this embodiment, when the online oxygen analyzer 10 detects that the oxygen content is greater than 3%, the cut-off valve before the compressor is closed, and the venting cut-off valve at the top of the recovery gas buffer tank 9 is opened to vent, so as to ensure the smooth and safe operation of the recovery system.

[0041] like Figure 1As shown, further, a recovery valve 41 , a pressure gauge 21 and a pressure valve 22 are installed on the exhaust pipeline of the stripping tower 23 .

[0042] Specifically, the stripping tower 23 is filled with fillers, and the waste alkali liquid enters the distillation kettle 24 from top to bottom through the filler layer. The pressure gauge 21 and the pressure valve 22 detect and control the waste alkali liquid entering the cooler 35 from the stripping tower 23, and the recovery valve 41 controls the waste alkali liquid in the cooler 35 to flow back to the stripping tower 23.

[0043] like Figure 1 As shown, further, the distillation kettle 24 has a hot water inlet pipeline 18 and a hot water return pipeline 20, the hot water inlet pipeline 18 is installed with a second regulating valve front valve 15, a second regulating valve 16 and a second regulating valve rear valve 17, and the hot water return pipeline 20 is installed with a second return valve 19 and a first liquid level meter 25.

[0044] Specifically, the waste alkali liquid enters the distillation kettle 24 from top to bottom through the packing layer. When a certain liquid level is reached in the distillation kettle 24, the gas recovery valve 41 at the top of the stripping tower 23 is opened, the second regulating valve 16 and the second hot water return valve 19 of the hot water inlet pipeline 18 of the shell side of the distillation kettle 24 are opened, and the distillation kettle 24 is slowly heated. When a certain temperature is reached, the VCM gas is cooled by the cooler 35.

[0045] like Figure 1 As shown, the first liquid level meter 25 is a field liquid level meter.

[0046] Specifically, the staff observes the liquid level height in the distillation kettle 24 on site through the first liquid level meter 25, which is convenient for the operation of subsequent work.

[0047] like Figure 1 As shown, the distillation kettle 24 is also equipped with a second liquid level gauge 29 and a second thermometer 28 . The second liquid level gauge 29 has a top valve 26 and a bottom valve 27 .

[0048] Specifically, the second thermometer 28 installed on the still 24 can check the temperature of the waste alkali liquid in the still 24. The second liquid level meter 29 is remotely observed to check the liquid level of the waste alkali liquid in the still 24. Then, the liquid level of the waste alkali liquid in the still 24 is remotely controlled through the top valve 26 and the bottom valve 27.

[0049] like Figure 1 As shown, the second liquid level gauge 29 is a remote liquid level gauge.

[0050] Specifically, the liquid level of the waste alkali solution in the distillation kettle 24 can be remotely checked through the second liquid level meter 29. This makes the operator's work more flexible and facilitates remote observation and remote control.

[0051] like Figure 1As shown, the distillation kettle 24 also has a second outlet pipeline 34 , on which an alkali solution outlet valve 30 , a third regulating valve front valve 31 , a third regulating valve 32 and a third regulating valve rear valve 33 are installed.

[0052] Specifically, when the online oxygen analyzer 10 detects that the oxygen content in the vacuum pump 14 exceeds the standard, the heated waste alkali liquid enters the waste alkali buffer tank 42 through the alkali liquid outlet valve 30 and the third regulating valve 32 at the bottom of the distillation kettle 24 .

[0053] The beneficial effect of this embodiment is that through the online oxygen analyzer 10 arranged on the vacuum pump 14, when the online oxygen analyzer 10 detects that the oxygen content in the vacuum pump 14 exceeds the standard, the online oxygen analyzer 10 is interlocked with the settings on the recovery pipeline 4 and the settings on the vent pipeline 5 on the recovery gas buffer tank 9, the shut-off valve before recovery to the compressor is closed, and the vent shut-off valve on the top of the recovery gas buffer tank 9 is opened to vent, so as to ensure smooth and safe operation of the recovery system.

[0054] The working process of this embodiment is as follows: the stripping tower 23 is filled with fillers, the waste alkali liquid enters the still 24 from top to bottom through the filler layer, the vacuum pump 14 is started, and the pressure of the stripping tower 23 is controlled to a certain range by the vacuum pump 14. The pressure gauge 21 and the pressure valve 22 can detect and control the waste alkali liquid entering the cooler 35 from the stripping tower 23, and the waste alkali liquid refluxed from the cooler 35 to the stripping tower 23 is controlled by the recovery valve 41. When there is a certain liquid level in the still 24, the gas recovery valve 41 at the top of the stripping tower 23 is opened, the second regulating valve 16 and the second hot water return valve 19 of the hot water inlet pipeline 18 of the shell side of the still 24 are opened, and the still 24 is slowly heated up. When a certain temperature is reached, the VCM gas is cooled by the cooler 35. When the online oxygen analyzer 10 detects that the oxygen content in the vacuum pump 14 exceeds the standard, the online oxygen analyzer 10 is interlocked with the settings on the recovery pipeline 4 and the vent pipeline 5 on the recovery gas buffer tank 9, the shut-off valve before recovery to the compressor is closed, and the vent shut-off valve on the top of the recovery gas buffer tank 9 is opened to vent, and the heated waste alkali liquid enters the waste alkali buffer tank 42 through the alkali liquid outlet valve 30 at the bottom of the distillation kettle 24 and the third regulating valve 32.

[0055] Example 2

[0056] like Figure 1As shown, the first outlet pipeline 12 of the vacuum pump 14 is connected to the recovery gas buffer tank 9, the first inlet pipeline 13 of the vacuum pump 14 is connected to the cooler 35, the first inlet pipeline 13 of the vacuum pump 14 is connected to the venting pipeline 5 of the recovery gas buffer tank 9, an online oxygen analyzer 10 is installed on the first outlet pipeline 12 of the vacuum pump, the top exhaust pipeline of the stripping tower 23 is connected to the vacuum pump 14, the bottom of the stripping tower 23 is installed with a distillation kettle 24, and the second outlet pipeline 34 of the distillation kettle 24 is connected to the waste alkali buffer tank 42.

[0057] Specifically, the online oxygen analyzer 10 is arranged on the vacuum pump 14, and the online oxygen analyzer 10 is interlocked with the arrangement on the recovery pipeline 4 and the venting pipeline 5 on the recovery gas buffer tank 9, and the recovery pipeline 4 is the pipeline before the compressor. When the online oxygen analyzer 10 detects that the oxygen content exceeds the standard, the cut-off valve before the compressor is closed, and the venting cut-off valve at the top of the recovery gas buffer tank 9 is opened to vent, so as to ensure the smooth and safe operation of the recovery system.

[0058] like Figure 1 As shown, further, a recovery valve 41 , a pressure gauge 21 and a pressure valve 22 are installed on the exhaust pipeline of the stripping tower 23 .

[0059] Specifically, the stripping tower 23 is filled with fillers, and the waste alkali liquid enters the distillation kettle 24 from top to bottom through the filler layer. The pressure gauge 21 and the pressure valve 22 detect and control the waste alkali liquid entering the cooler 35 from the stripping tower 23, and the recovery valve 41 controls the waste alkali liquid in the cooler 35 to flow back to the stripping tower 23.

[0060] like Figure 1 As shown, further, the distillation kettle 24 has a hot water inlet pipeline 18 and a hot water return pipeline 20, the hot water inlet pipeline 18 is installed with a second regulating valve front valve 15, a second regulating valve 16 and a second regulating valve rear valve 17, and the hot water return pipeline 20 is installed with a second return valve 19 and a first liquid level meter 25.

[0061] Specifically, the waste alkali liquid enters the distillation kettle 24 from top to bottom through the packing layer. When a certain liquid level is reached in the distillation kettle 24, the gas recovery valve 41 at the top of the stripping tower 23 is opened, the second regulating valve 16 and the second hot water return valve 19 of the hot water inlet pipeline 18 of the shell side of the distillation kettle 24 are opened, and the distillation kettle 24 is slowly heated. When a certain temperature is reached, the VCM gas is cooled by the cooler 35.

[0062] like Figure 1 As shown, the first liquid level meter 25 is a field liquid level meter.

[0063] Specifically, the staff observes the liquid level height in the distillation kettle 24 on site through the first liquid level meter 25, which is convenient for the operation of subsequent work.

[0064] like Figure 1 As shown, the distillation kettle 24 is also equipped with a second liquid level gauge 29 and a second thermometer 28 . The second liquid level gauge 29 has a top valve 26 and a bottom valve 27 .

[0065] Specifically, the second thermometer 28 installed on the still 24 can check the temperature of the waste alkali liquid in the still 24. The second liquid level meter 29 is remotely observed to check the liquid level of the waste alkali liquid in the still 24. Then, the liquid level of the waste alkali liquid in the still 24 is remotely controlled through the top valve 26 and the bottom valve 27.

[0066] like Figure 1 As shown, the second liquid level gauge 29 is a remote liquid level gauge.

[0067] Specifically, the liquid level of the waste alkali solution in the distillation kettle 24 can be remotely checked through the second liquid level meter 29. This makes the operator's work more flexible and facilitates remote observation and remote control.

[0068] like Figure 1 As shown, the distillation kettle 24 also has a second outlet pipeline 34 , on which an alkali solution outlet valve 30 , a third regulating valve front valve 31 , a third regulating valve 32 and a third regulating valve rear valve 33 are installed.

[0069] Specifically, when the online oxygen analyzer 10 detects that the oxygen content in the vacuum pump 14 exceeds the standard, the heated waste alkali liquid enters the waste alkali buffer tank 42 through the alkali liquid outlet valve 30 and the third regulating valve 32 at the bottom of the distillation kettle 24 .

[0070] like Figure 1 As shown, a vacuum pump 14 is fixedly installed at the gas phase outlet of the cooler 35, and a cooling water inlet pipeline and a cooling water return pipeline are installed in the cooler 35. A first regulating valve front valve 37, a first regulating valve 38 and a first regulating valve rear valve 39 are installed on the cooling water inlet pipeline, a first return valve 40 is installed on the cooling water return pipeline, and a first thermometer 36 is also installed at the outlet of the cooler 35.

[0071] Specifically, a first thermometer 36 is fixedly installed at the outlet of the cooler 35, and the shell side is cooling water. The VCM and acetylene gas temperatures at the outlet of the cooler 35 are controlled by the first regulating valve front valve 37, the first regulating valve 38 and the first regulating valve rear valve 39 on the cooling water inlet pipeline. The first regulating valve 38 and the first thermometer 36 are automatically controlled and regulated.

[0072] like Figure 1As shown, a drain pipeline is fixedly installed at the bottom of the recovery gas buffer tank 9, and a sewage discharge manual valve 11 is installed on the drain pipeline. A recovery pipeline 4 and a venting pipeline 5 are installed on the top of the recovery gas buffer tank 9. The recovery pipeline 4 is installed with a first interlock cut-off valve rear valve 1, a first interlock cut-off valve 2 and a first interlock cut-off valve front valve 3, and the venting pipeline 5 is installed with a second interlock cut-off valve 6, a second interlock cut-off valve rear valve 7 and a flame arrester 8.

[0073] Specifically, through the online oxygen analyzer 10 arranged on the vacuum pump 14, the online oxygen analyzer 10 and the first interlock cut-off valve rear valve 1, the first interlock cut-off valve 2 and the first interlock cut-off valve front valve 3 on the recovery gas buffer tank 9, the second interlock cut-off valve 6 and the second interlock cut-off valve rear valve 7 installed on the vent pipeline 5 are arranged to be interlocked. When the online oxygen analyzer 10 detects that the oxygen content exceeds the standard, the first interlock cut-off valve 2 is closed, and the second interlock cut-off valve 6 on the top of the recovery gas buffer tank 9 is opened to vent. At the same time, the flame arrester 8 can prevent the leaked oxygen from burning to ensure the smooth and safe operation of the recovery system.

[0074] The beneficial effect of this embodiment is: through the online oxygen analyzer 10 arranged on the vacuum pump 14, when the online oxygen analyzer 10 detects that the oxygen content in the vacuum pump 14 is not exceeded, the online oxygen analyzer 10 is interlocked with the settings on the recovery pipeline 4 on the recovery gas buffer tank 9 and the settings on the vent pipeline 5 and opened, the shut-off valve before recovery to the compressor is opened, and the vent shut-off valve on the top of the recovery gas buffer tank 9 is closed and vented to ensure smooth and safe operation of the recovery system.

[0075] The working process of this embodiment is as follows: the stripping tower 23 is filled with fillers, the waste alkali liquid enters the still 24 from top to bottom through the filler layer, the vacuum pump 14 is started, and the pressure of the stripping tower 23 is controlled to a certain range by the vacuum pump 14. The pressure gauge 21 and the pressure valve 22 can detect and control the waste alkali liquid entering the cooler 35 from the stripping tower 23, and the waste alkali liquid in the cooler 35 is controlled by the recovery valve 41 to flow back to the stripping tower 23. When there is a certain liquid level in the still 24, the gas recovery valve 41 at the top of the stripping tower 23 is opened, the second regulating valve 16 and the second hot water return valve 19 of the shell side hot water inlet pipeline 18 of the still 24 are opened, and the still 24 is slowly heated. When a certain temperature is reached, the VCM gas is cooled by the cooler 35. When the online oxygen content analyzer 10 detects that the oxygen content in the vacuum pump 14 does not exceed the standard, in this embodiment, the oxygen content standard in the vacuum pump 14 is less than or equal to 3%. A first thermometer 36 is fixedly installed at the outlet of the cooler 35 to monitor the temperature of VCM and acetylene gas at the outlet of the cooler 35. The water inlet and return pipes of the cooler 35 are opened, and the shell side is cooling water. The temperature of VCM and acetylene gas at the outlet of the cooler 35 is controlled by the first regulating valve front valve 37, the first regulating valve 38 and the first regulating valve rear valve 39 on the cooling water inlet pipeline. The first regulating valve 38 and the first thermometer 36 are automatically controlled and regulated. The oxygen content in the vacuum pump 14 is analyzed by the online oxygen analyzer 10 set on the vacuum pump 14, the first interlocking cut-off valve 2 on the recovery gas buffer tank 9 is opened, and the second interlocking cut-off valve 6 installed on the venting pipeline 5 is closed and vented. The VCM and acetylene gas cooled by the cooler 35 enter the recovery gas buffer tank 9 for buffering and are then sent to the downstream for recycling.

[0076] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0077] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0078] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0079] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a 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 higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0080] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0081] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A device for recovering alkali liquor and organic gas in the production of PVC by calcium carbide process, characterized in that: The invention comprises a recovery gas buffer tank (9), a vacuum pump (14), an online oxygen analyzer (10), a cooler (35), a stripping tower (23), a distillation kettle (24) and a waste alkali buffer tank (42). The first outlet pipeline (12) of the vacuum pump (14) is connected to the recovery gas buffer tank (9), the first inlet pipeline (13) of the vacuum pump (14) is connected to the cooler (35), the first inlet pipeline (13) is connected to the venting pipeline (5) of the recovery gas buffer tank (9), the online oxygen analyzer (10) is installed on the first outlet pipeline (12) of the vacuum pump, the top exhaust pipeline of the stripping tower (23) is connected to the vacuum pump (14), the distillation kettle (24) is installed at the bottom of the stripping tower (23), and the second outlet pipeline (34) of the distillation kettle (24) is connected to the waste alkali buffer tank (42).

2. The device for recovering alkali liquor and organic gas in the production of PVC by calcium carbide process according to claim 1, characterized in that: A recovery valve (41), a pressure gauge (21) and a pressure valve (22) are installed on the exhaust pipeline of the stripping tower (23).

3. The device for recovering alkali liquor and organic gas in the production of PVC by calcium carbide process according to claim 1, characterized in that: The distillation kettle (24) has a hot water inlet pipeline (18) and a hot water return pipeline (20). The hot water inlet pipeline (18) is equipped with a second regulating valve front valve (15), a second regulating valve (16) and a second regulating valve rear valve (17). The hot water return pipeline (20) is equipped with a second return valve (19) and a first liquid level meter (25).

4. The device for recovering alkali liquor and organic gas in the production of PVC by calcium carbide process according to claim 3, characterized in that: The first liquid level meter (25) is an on-site liquid level meter.

5. The device for recovering alkali liquor and organic gas in the production of PVC by calcium carbide process according to claim 3, characterized in that: The second outlet pipeline (34) is equipped with an alkali solution outlet valve (30), a third regulating valve front valve (31), a third regulating valve (32) and a third regulating valve rear valve (33).

6. The device for recovering alkali liquor and organic gas in the production of PVC by calcium carbide process according to claim 3, characterized in that: The distillation kettle (24) is also equipped with a second liquid level gauge (29) and a second thermometer (28), and the second liquid level gauge (29) has a top valve (26) and a bottom valve (27).

7. The device for recovering alkali liquor and organic gas in the production of PVC by calcium carbide process according to claim 6, characterized in that: The second liquid level meter (29) is a remote liquid level meter.

8. The device for recovering alkali liquor and organic gas in the production of PVC by calcium carbide process according to claim 1, characterized in that: A vacuum pump (14) is fixedly installed at the gas phase outlet of the cooler (35); a cooling water inlet pipeline and a cooling water return pipeline are installed in the cooler (35); a first regulating valve front valve (37), a first regulating valve (38) and a first regulating valve rear valve (39) are installed on the cooling water inlet pipeline; a first return valve (40) is installed on the cooling water return pipeline; and a first thermometer (36) is also installed at the outlet of the cooler (35).

9. The device for recovering alkali liquor and organic gas in the production of PVC by calcium carbide process according to claim 1, characterized in that: A liquid discharge pipeline is fixedly installed at the bottom of the recovery gas buffer tank (9), and a sewage discharge manual valve (11) is installed on the liquid discharge pipeline. A recovery pipeline (4) and a venting pipeline (5) are installed at the top of the recovery gas buffer tank (9). A first interlock cut-off valve rear valve (1), a first interlock cut-off valve (2) and a first interlock cut-off valve front valve (3) are installed on the recovery pipeline (4), and a second interlock cut-off valve (6), a second interlock cut-off valve rear valve (7) and a flame arrester (8) are installed on the venting pipeline (5).

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