Waste heat recovery system in PVC (polyvinyl chloride) production
By designing a waste heat recovery system in PVC production, and using heat exchangers and reflow systems to recover and utilize waste heat, the problems of waste heat waste and high energy consumption in PVC production are solved, and efficient utilization of heat energy and reduction of production energy consumption are achieved.
Patent Information
- Application Number
- CN202421613177.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-09
- Publication Date
- 2025-05-13
- Estimated Expiration
- 2034-07-09
AI Technical Summary
During the PVC production process, waste heat cannot be effectively recycled and utilized, resulting in large heat waste and production energy consumption.
A waste heat recovery system in PVC production is designed. By setting a heat exchanger and a reflux system in the polymerization kettle, stripping tower and drying process, the waste heat of the slurry, the reaction heat in the polymerization reaction and the waste heat in the drying process are recovered and utilized.
It effectively avoids heat waste, improves heat energy utilization, reduces steam consumption of multiple devices, and reduces production energy consumption, achieving the purpose of energy saving and consumption reduction.
Smart Images
Figure CN222865671U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of polyvinyl chloride production, in particular to a waste heat recovery system in PVC production. Background Art
[0002] In the PVC production process, after the polymerization reaction is completed, due to the dissolution and adsorption of PVC particles, the slurry still contains 1-3% by mass of VCM monomer residue. In production, the slurry must be stripped before entering the centrifuge, otherwise the residual VCM monomer will diffuse, which will affect the quality of the resin product and cause a certain degree of environmental pollution. The stripping tower mainly consumes steam to ensure the stripping effect, so the materials taken out from the top of the stripping tower and the bottom of the tower will carry more waste heat. In the PVC production process, a lot of similar waste heat will be generated, such as the reaction heat in the polymerization reactor, the residual heat in the centrifugal drying stage, etc. If this heat is not effectively recovered and utilized, it will cause heat waste and lead to large energy loss in the production process. Utility Model Content
[0003] The utility model provides a waste heat recovery system in PVC production, which is used to solve the problems of energy loss and waste, high production energy consumption, etc. caused by less waste heat recovery in the existing PVC production process.
[0004] The utility model provides a waste heat recovery system in PVC production, comprising: a polymerization kettle, the polymerization kettle is connected with a discharge trough, the discharge trough is connected with a stripping feed trough through a slurry pump, the stripping feed trough is connected with a feed port of a stripping tower through a stripping feed pump, the top sampling port of the stripping tower is sequentially connected with a primary condenser, a secondary condenser, a separator and a vacuum pump, the liquid discharge port of the separator is connected with a monomer tank; the bottom slurry outlet of the stripping tower is connected with a heat medium inlet of a polymerization hot water tank through a slurry outlet pump, the heat medium outlet of the polymerization hot water tank is connected with a drying slurry tank, the drying slurry tank is connected with a centrifuge, the mother liquor outlet of the centrifuge is connected with a heat medium inlet of a fluidized bed air preheater, and the heat medium outlet of the fluidized bed air preheater is connected with a polymerization flushing tank.
[0005] Preferably, a feed heat exchanger is arranged between the stripping feed pump and the feed port of the stripping tower, the cold medium inlet and the cold medium outlet of the feed heat exchanger are respectively connected to the outlet of the stripping feed pump and the feed port of the stripping tower, and the hot medium inlet and the hot medium outlet of the feed heat exchanger are respectively connected to the outlet of the slurry pump and the hot medium inlet of the polymerization hot water tank.
[0006] Preferably, the outlet of the slurry pump is divided into two paths, one of which is connected to the spray reflux port of the stripping tower through a pipeline, and the other is connected to the heat medium inlet of the polymerization hot water tank.
[0007] Preferably, the heat medium inlet and outlet pipes of the feed heat exchanger are respectively installed with shut-off valves, a straight pipe is connected between the two shut-off valves, and the straight pipe is connected in parallel with the feed heat exchanger; a slurry control valve is provided on the straight pipe.
[0008] Preferably, the heat medium inlet of the polymerization hot water tank is also connected to a conversion hot water tank and a 3 kg steam network, and the hot water inlet of the conversion hot water tank is connected to the water jacket of the polymerization kettle.
[0009] Preferably, the feed heat exchanger is a spiral plate exchanger.
[0010] Preferably, the stripping tower includes a tower body, which includes an upper empty tower section and a lower tower plate section, wherein a plurality of tower plates are arranged in the tower plate section, and a plurality of through holes are evenly distributed on the tower plates; an annular spray component is arranged at the upper part of the empty tower section, and the inlet of the annular spray component is connected to the spray reflux port; a steam inlet is arranged below the tower plate section; a feed port of the stripping tower is arranged in the middle part of the empty tower section, and the feed port is connected to a slurry inlet pipe arranged inside the empty tower section.
[0011] Preferably, the height of the empty column section accounts for 25-50% of the height of the stripping column.
[0012] Preferably, the top production outlet of the stripping tower is connected to a guide pipe arranged inside the stripping tower, and a plurality of liquid baffles are evenly distributed along the circumferential direction inside the guide pipe, and the width of the liquid baffles does not exceed the radius of the guide pipe.
[0013] Preferably, a liquid distributor is provided between the slurry inlet pipe and the tower plate section.
[0014] The waste heat recovery system in PVC production provided by the utility model recycles and utilizes the waste heat of slurry in the stripping tower, the reaction heat in the polymerization reaction, the waste heat in the slurry centrifugal drying process, etc., and maximizes the recovery and utilization of waste heat in PVC production, thereby avoiding heat waste, improving the utilization rate of thermal energy, reducing the steam consumption of multiple devices, and reducing the heating steam of some devices from the commonly used 7 kg level to the 3 kg level, effectively reducing steam consumption and heat loss, reducing production energy consumption as a whole, and achieving the purpose of energy saving and consumption reduction.
[0015] The stripping tower in this system optimizes the material flow field distribution mode by cooperating with the empty tower section and the tower plate section, and cooperates with the annular spray components, tower plates, etc. to provide different material contact modes, so as to quickly separate the VCM monomer. The stripping separation effect is good, which not only recycles the VCM monomer and reduces the raw material loss, but also improves the quality of PVC products. At the same time, the slurry at the bottom of the stripping tower is used to preheat the feed, which significantly reduces the steam consumption of the stripping tower. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0017] Figure 1 A schematic diagram of the structure of a waste heat recovery system in PVC production provided by one embodiment of the utility model;
[0018] Figure 2 A schematic diagram of the structure of a stripping tower provided in one embodiment of the utility model;
[0019] Figure 3 for Figure 2 An enlarged schematic diagram of point A.
[0020] Description of reference numerals:
[0021] 1. Polymerization kettle, 2. Stripping feed tank, 3. Stripping tower, 4. Polymerization hot water tank, 5. Drying slurry tank, 6. Centrifuge, 7. Fluidized bed air preheater, 8. Polymerization flushing tank, 9. Conversion hot water tank, 11. Discharge tank, 12. Slurry pump, 13. Monomer tank, 21. Stripping feed pump, 31. Primary condenser, 32. Secondary condenser, 33. Separator, 34. Vacuum pump, 35. Slurry pump, 36. Feed heat exchanger, 301. Inlet Material inlet, 302, top production outlet, 303, bottom slurry outlet, 304, spray reflux outlet, 305, tower body, 306, steam inlet, 307, liquid distributor, 361, shut-off valve, 362, straight pipeline, 363, slurry control valve, 3011, slurry inlet pipe, 3021, guide pipe, 3022, liquid baffle plate, 3041, annular spray component, 3051, empty tower section, 3052, tower plate section, 3053, tower plate. DETAILED DESCRIPTION
[0022] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution in the embodiments of the utility model is described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work also fall within the scope of protection of the utility model.
[0023] like Figure 1 and Figure 2The utility model provides a waste heat recovery system in PVC production, comprising: a polymerization kettle 1, the polymerization kettle 1 is connected to a discharge tank 11, the discharge tank 11 is connected to a stripping feed tank 2 through a slurry pump 12, the stripping feed tank 2 is connected to a feed port 301 of a stripping tower 3 through a stripping feed pump 21, the top production port 302 of the stripping tower 3 is connected to a primary condenser 31, a secondary condenser 32, a separator 33 and a vacuum pump 34 in sequence, the discharge port of the separator 33 is connected to a monomer tank 13; the bottom slurry outlet 303 of the stripping tower 3 is connected to a heat medium inlet of a polymerization hot water tank 4 through a slurry outlet pump 35, the heat medium inlet of the polymerization hot water tank 4 The mother liquor outlet is connected to the drying slurry tank 5, the drying slurry tank 5 is connected to the centrifuge 6, the mother liquor outlet of the centrifuge 6 is connected to the hot medium inlet of the fluidized bed air preheater 7, and the hot medium outlet of the fluidized bed air preheater 7 is connected to the polymerization flushing tank 8; a feed heat exchanger 36 is arranged between the stripping feed pump 21 and the feed port 301 of the stripping tower 3, the cold medium inlet and the cold medium outlet of the feed heat exchanger 36 are respectively connected to the outlet of the stripping feed pump 21 and the feed port 301 of the stripping tower 3, and the hot medium inlet and the hot medium outlet of the feed heat exchanger 36 are respectively connected to the outlet of the slurry pump 35 and the hot medium inlet of the polymerization hot water tank 4.
[0024] The product slurry formed after the polymerization reaction in the polymerization kettle 1 is discharged to the discharge tank 11 for temporary storage, and then the slurry is sent to the stripping feed tank 2 through the slurry pump 12 for refining and separation. The stripping feed pump 21 pumps the slurry in the stripping feed tank 2 into the stripping tower 3. The slurry with high heat discharged from the slurry outlet 303 at the bottom of the stripping tower 3 first passes through the feed heat exchanger 36 to preheat the slurry from the stripping feed tank 2, and then enters the heat medium pipeline of the polymerization hot water tank 4 to perform primary heating on the desalted water in the polymerization hot water tank 4. While reducing the temperature of the slurry discharged from the bottom of the stripping tower 3, the heat of the high-temperature slurry discharged from the stripping tower 3 is used to increase the temperature of the slurry entering the stripping tower 3 and the temperature of the desalted water in the polymerization hot water tank 4, thereby reducing the amount of steam used for heating in the stripping tower 3 and the polymerization hot water tank 4, and also reducing steam loss, reducing production costs, and improving thermal energy utilization. Similarly, the slurry after cooling enters the drying slurry tank 5 to be prepared for centrifugal drying. The solid obtained by centrifugation in the centrifuge 6 is sent to the fluidized bed for drying to obtain the PVC product. The centrifugal mother liquor is used to preheat the drying air for the fluidized bed in advance, which can significantly reduce the steam consumption for fluidized bed drying.
[0025] After the waste heat of the centrifugal mother liquor is recovered, it is sent to the polymerization flushing tank 8. The centrifugal mother liquor can be used to flush the slurry pipeline and the polymerization kettle 1, which saves the amount of desalted water used for flushing the polymerization kettle 1, and also reduces the amount of wastewater discharged, with a significant emission reduction effect. After the slurry in the stripping feed tank 2 is separated by the stripping tower 3, high VCM steam is extracted from the top extraction port 302 of the stripping tower 3. After condensation and separation, the gas part can be pumped to the exhaust gas system through the vacuum pump 34, and the VCM in the liquid part is sent back to the monomer tank 13 for continued use. While saving resources and improving the quality of PVC products, it also improves the effective utilization rate of raw materials and reduces the operating load of various devices for centrifugal drying.
[0026] like Figure 1 and Figure 2 Preferably, the outlet of the slurry pump 35 is divided into two paths, one of which is connected to the spray reflux port 304 of the stripping tower 3 through a pipeline, and the other is connected to the heat medium inlet of the polymerization hot water tank 4. The slurry pump 35 divides the slurry into two paths, one of which is sent back to the stripping tower 3 as reflux for spray circulation, which can accelerate the separation of VCM and PVC in the feed by spraying, thereby improving the separation effect of the stripping tower 3, and the other is used for waste heat recovery and output of PVC products.
[0027] like Figure 1 Preferably, the heat medium inlet and outlet pipes of the feed heat exchanger 36 are respectively installed with a shutoff valve 361, a straight-through pipe 362 is connected between the two shutoff valves 361, and the straight-through pipe 362 is connected in parallel with the feed heat exchanger 36; a slurry control valve 363 is provided on the straight-through pipe 362. Through the cooperation of the shutoff valve 361 on the heat medium pipe of the feed heat exchanger 36 and the slurry control valve 363 on the straight-through pipe 362, the feed heat exchanger 36 can be cut in or out of the system during the operation of the system, so as to facilitate the temperature control of the feed heat exchanger 36 and the stripping tower 3.
[0028] Preferably, the heat medium inlet of the polymerization hot water tank 4 is also connected to the conversion hot water tank 9 and the 3 kg steam network, and the hot water inlet of the conversion hot water tank 9 is connected to the water jacket of the polymerization kettle 1 .
[0029] The desalted water in the polymerization hot water tank 4 is mainly used as a dispersion medium to disperse the VCM monomer and evenly suspend it in the reaction raw materials of the polymerization kettle 1 to facilitate the polymerization reaction. In order to quickly disperse or react, the desalted water needs to be heated in advance. In the preferred heating scheme, the polymerization hot water tank 4 first uses the waste heat from the bottom of the stripping tower 3 for primary heating, and then uses the conversion hot water in the conversion hot water tank 9 that absorbs the heat of the polymerization reaction for secondary heating, and finally uses 3 kg of steam to heat to the set temperature. In this heating scheme, various waste heats are fully utilized, and the heating steam is reduced from the commonly used 7 kg level to the 3 kg level, which effectively reduces the steam consumption and heat loss, and has a significant energy-saving and consumption-reducing effect. Among them, the conversion hot water after cooling can be recycled, and the process condensate such as steam condensate is also fully recovered for comprehensive utilization.
[0030] Preferably, the feed heat exchanger 36 is a spiral plate exchanger. In the process of mutual heat exchange between slurries, the spiral plate exchanger is more convenient to eliminate channel dead corners and heat exchange dead corners, obtain higher heat exchange efficiency, and further reduce the steam consumption of the stripping tower 3.
[0031] like Figure 2 Preferably, the stripping tower 3 comprises a tower body 305, the tower body 305 comprises an upper empty tower section 3051 and a lower tower plate section 3052, a plurality of tower plates 3053 are arranged in the tower plate section 3052, and a plurality of through holes are evenly distributed on the tower plates 3053; an annular spray component 3041 is arranged at the upper part of the empty tower section 3051, and the inlet of the annular spray component 3041 is connected to the spray reflux port 304; a steam inlet 306 is arranged below the tower plate section 3052; a feed port 301 of the stripping tower 3 is arranged in the middle part of the empty tower section 3051, and the feed port 301 is connected to a slurry inlet pipe 3011 arranged inside the empty tower section 3051. More preferably, the height of the empty tower section 3051 accounts for 25-50% of the height of the stripping tower 3.
[0032] Through the cooperation of the empty tower section 3051 and the tray section 3052 of the stripping tower 3, the material flow field distribution mode in the stripping tower 3 can be optimized, and the annular spray component 3041, the tray 3053, etc. provide different material contact modes, the internal heat transfer efficiency is high, the VCM monomer can be quickly separated, and because the feed heat exchanger 36 preheats the feed, the steam consumption of the stripping tower 3 is also small. The annular spray component 3041 adopts a combination of spray pipes and nozzles commonly used in the art, as long as an annular spray can be formed inside the empty tower section 3051, and no special limitation is made here.
[0033] The slurry enters the stripping tower 3 through the feed port 301 and the slurry inlet pipe 3011, and forms a uniformly distributed material layer on the plate 3053 of the plate section 3052. After being fully contacted with the steam entering from the steam inlet 306, the VCM and PVC in the slurry are separated to ensure that the residual vinyl chloride content in the PVC resin product meets the standard. The PVC slurry flows downward and is finally discharged from the slurry outlet 303 at the bottom of the stripping tower 3. A part of the discharged slurry flows back into the stripping tower 3 through the spray reflux port 304 and the annular spray component 3041. The VCM flows upward and contacts the spray reflux slurry in the empty tower section 3051, washing the PVC product entrained in the VCM and improving the slurry stripping effect.
[0034] like Figure 3 Preferably, the top outlet 302 of the stripping tower 3 is connected to a guide pipe 3021 disposed inside the stripping tower 3, and a plurality of liquid baffles 3022 are evenly distributed along the circumference inside the guide pipe 3021, and the width of the liquid baffles 3022 does not exceed the radius of the guide pipe 3021. The guide pipe 3021 guides the steam containing VCM to the top outlet 302, so that it can be discharged from the stripping tower 3. The liquid baffles 3022 are arranged in the guide pipe 3021, which can slow down the discharge speed of the steam and change its wind pattern or flow direction, and block the droplets entrained in the steam, so as to prevent the steam from carrying the material and reducing the loss of PVC products.
[0035] like Figure 2 Preferably, a liquid distributor 307 is provided between the slurry inlet pipe 3011 and the tray section 3052. The liquid distributor 307 can be a distributor commonly used in the art, and its specific structure is not limited here. The liquid distributor 307 is provided at the lower end of the slurry inlet pipe 3011, and is used to distribute the feed material so that it has a larger landing surface and can evenly fall onto the first tray 3053 of the tray section 3052. At the same time, it can also redistribute the spray liquid falling from the empty tray section 3051, thereby improving the uniformity and efficiency of mass and heat transfer in the tray section 3052 and ensuring the stripping separation effect.
[0036] The waste heat recovery system in PVC production provided by the utility model is specifically operated, in which the product slurry formed after the polymerization reaction in the polymerization kettle 1 is discharged to the discharge tank 11 for temporary storage, and then the slurry is sent to the stripping feed tank 2 through the slurry pump 12 for preparation for refining and separation. The stripping feed pump 21 pumps the slurry in the stripping feed tank 2 into the stripping tower 3, and the high VCM steam is sampled from the sampling port 302 at the top of the stripping tower 3, which is condensed in turn by the primary condenser 31 and the secondary condenser 32, and then separated by the separator 33. The gas part can be pumped to the waste gas system through the vacuum pump 34, and the VCM in the liquid part is sent back to the monomer tank 13 for continued use.
[0037] The slurry with high heat discharged from the slurry outlet 303 at the bottom of the stripping tower 3 is divided into two paths from the outlet of the slurry pump 35. One path is sent back to the stripping tower 3 as reflux for spray circulation, and the other path first passes through the feed heat exchanger 36 to preheat the slurry from the stripping feed tank 2. The above-mentioned feed heat exchanger 36 is a spiral plate exchanger. At the same time, the feed heat exchanger 36 can be cut into or out of the system through the cooperation of the shut-off valve 361, the slurry control valve 363 and the straight pipe 362, so as to facilitate the temperature control of the feed heat exchanger 36 and the stripping tower 3.
[0038] The slurry cooled from the feed heat exchanger 36 enters the heat medium pipeline of the polymerization hot water tank 4, and the desalted water in the polymerization hot water tank 4 is heated primarily. Then the polymerization hot water tank 4 uses the conversion hot water in the conversion hot water tank 9 that absorbs the heat of the polymerization reaction for secondary heating, and finally uses 3 kg of steam to heat the desalted water therein to the set temperature. The conversion hot water after cooling can be recycled, and the process condensate such as the steam condensate is also fully recovered for comprehensive utilization.
[0039] The cooled slurry from the polymerization hot water tank 4 enters the drying slurry tank 5 to be prepared for centrifugal drying. The solid obtained by centrifugation in the centrifuge 6 is sent to the fluidized bed for drying to obtain the PVC product. The centrifugal mother liquor is sent to the fluidized bed air preheater 7 to preheat the dry air for the fluidized bed in advance, which can significantly reduce the steam consumption for fluidized bed drying. The centrifugal mother liquor is sent to the polymerization flushing tank 8 after the waste heat is recovered. The centrifugal mother liquor can be used to flush the slurry pipeline and the polymerization kettle 1, saving the amount of desalted water used for flushing the polymerization kettle 1.
[0040] When the above-mentioned stripping tower 3 is in operation, the slurry is preheated by the feed heat exchanger 36, and then enters the slurry inlet pipe 3011 through the feed port 301 and is discharged. The slurry falls downward to the liquid distributor 307 and is dispersed in the stripping tower 3, and then falls to the tray 3053 of the tray section 3052, and after being fully contacted with the steam entering from the steam inlet 306, the VCM and PVC in the slurry are separated, and the PVC slurry flows downward and is finally discharged from the slurry outlet 303 at the bottom of the stripping tower 3. A part of the discharged slurry refluxes into the stripping tower 3 through the spray reflux port 304 and the annular spray component 3041, and the VCM flows upward and contacts with the spray refluxed slurry in the empty tower section 3051, and the PVC product entrained in the VCM is washed, thereby improving the slurry stripping effect. After further mass transfer and heat transfer in the empty tower section 3051, the guide pipe 3021 guides the steam containing VCM to the top production port 302, and the liquid baffle 3022 arranged in the guide pipe 3021 blocks the droplets entrained in the steam to prevent the steam from carrying the material and reducing the loss of PVC products.
[0041] It should be noted that in the present invention, the detailed structure of some devices is not described in detail, but belongs to the prior art known to those skilled in the art, so it will not be repeated here. In addition, the parts not involved in the device are the same as the prior art or can be implemented by using the prior art.
[0042] It should be noted that pressure sensors, flow meters or temperature sensors are installed on the transmission pipelines inside the system between different units, devices or equipment. Different valves are also installed, such as pressure relief valves, pressure regulating valves, safety valves, etc., which are used to adjust and stabilize the pressure of the entire system.
[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it; although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in the field should understand that it is still possible to modify the technical solutions recorded in the aforementioned embodiments, or to replace some or all of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.
Claims
1. A waste heat recovery system in PVC production, characterized in that: include: A polymerization kettle, wherein the polymerization kettle is connected to a discharge trough, the discharge trough is connected to a stripping feed trough through a slurry pump, the stripping feed trough is connected to a feed port of a stripping tower through a stripping feed pump, the top outlet of the stripping tower is sequentially connected to a primary condenser, a secondary condenser, a separator and a vacuum pump, the discharge port of the separator is connected to a monomer tank; the bottom slurry outlet of the stripping tower is connected to a heat medium inlet of a polymerization hot water tank through a slurry outlet pump, the heat medium outlet of the polymerization hot water tank is connected to a drying slurry tank, the drying slurry tank is connected to a centrifuge, the mother liquor outlet of the centrifuge is connected to a heat medium inlet of a fluidized bed air preheater, and the heat medium outlet of the fluidized bed air preheater is connected to a polymerization flushing tank; A feed heat exchanger is arranged between the stripping feed pump and the feed port of the stripping tower, the cold medium inlet and the cold medium outlet of the feed heat exchanger are respectively connected to the outlet of the stripping feed pump and the feed port of the stripping tower, and the hot medium inlet and the hot medium outlet of the feed heat exchanger are respectively connected to the outlet of the slurry discharge pump and the hot medium inlet of the polymerization hot water tank.
2. The waste heat recovery system in PVC production according to claim 1, characterized in that: The outlet of the slurry discharge pump is divided into two paths, one of which is connected to the spray reflux port of the stripping tower through a pipeline, and the other is connected to the heat medium inlet of the polymerization hot water tank.
3. The waste heat recovery system in PVC production according to claim 2, characterized in that: The pipes of the heat medium inlet and outlet of the feed heat exchanger are respectively installed with shut-off valves, a straight pipe is connected between the two shut-off valves, and the straight pipe is connected in parallel with the feed heat exchanger; a slurry control valve is provided on the straight pipe.
4. The waste heat recovery system in PVC production according to claim 2, characterized in that: The heat medium inlet of the polymerization hot water tank is also connected to a conversion hot water tank and a 3 kg steam network, and the hot water inlet of the conversion hot water tank is connected to the water jacket of the polymerization kettle.
5. The waste heat recovery system in PVC production according to claim 2, characterized in that: The feed heat exchanger is a spiral plate exchanger.
6. The waste heat recovery system in PVC production according to any one of claims 2 to 5, characterized in that: The stripping tower comprises a tower body, which comprises an upper empty tower section and a lower tower plate section, wherein a plurality of tower plates are arranged in the tower plate section, and a plurality of through holes are evenly distributed on the tower plates; an annular spray component is arranged at the upper part of the empty tower section, and the inlet of the annular spray component is connected with the spray reflux port; a steam inlet is arranged below the tower plate section; the feed port of the stripping tower is arranged in the middle part of the empty tower section, and the feed port is connected to a slurry tower inlet pipe arranged inside the empty tower section.
7. The waste heat recovery system in PVC production according to claim 6, characterized in that: The height of the empty column section accounts for 25-50% of the height of the stripping column.
8. The waste heat recovery system in PVC production according to claim 6, characterized in that: The top production outlet of the stripping tower is connected to a guide pipe arranged inside the stripping tower, and a plurality of liquid baffles are evenly distributed circumferentially inside the guide pipe, and the width of the liquid baffles does not exceed the radius of the guide pipe.
9. The waste heat recovery system in PVC production according to claim 6, characterized in that: A liquid distributor is arranged between the slurry inlet pipe and the tower plate section.