阅读说明：本技术 一种pvc树脂的聚合装置和方法 (PVC resin polymerization device and method ) 是由 霍慧生 霍冰冰 苗泽慧 于 2019-11-25 设计创作，主要内容包括：本发明公开了一种PVC树脂的聚合装置和方法,本装置包括聚合釜、冷水升温换热器、热水恒温换热器和热水罐,所述聚合釜顶部设置有第一进料口、第二进料口、进水口、高压水进口、终止剂口,所述进水口连接热水罐；聚合釜底部设置有出料口、高压进气口,外壁设置有温控夹套,内部设置有搅拌装置、喷淋装置和内冷管；对聚合装置和聚合热水入料方法改造后,聚合进完料后无需升温,大大缩短了辅助时间,提高了釜的生产效率；避免了低温反应,减少了大分子量的数量；减少了水中含氧量的带入,提高了PVC树脂的热稳定性,能生产出高质量的PVC树脂。(The invention discloses a polymerization device and a polymerization method for PVC resin, wherein the device comprises a polymerization kettle, a cold water heating heat exchanger, a hot water constant temperature heat exchanger and a hot water tank, wherein the top of the polymerization kettle is provided with a first feed inlet, a second feed inlet, a water inlet, a high-pressure water inlet and a terminator port, and the water inlet is connected with the hot water tank; the bottom of the polymerization kettle is provided with a discharge port and a high-pressure air inlet, the outer wall of the polymerization kettle is provided with a temperature control jacket, and the inside of the polymerization kettle is provided with a stirring device, a spraying device and an inner cooling pipe; after the polymerization device and the polymerization hot water feeding method are improved, the temperature does not need to be raised after the polymerization feeding is finished, the auxiliary time is greatly shortened, and the production efficiency of the kettle is improved; low-temperature reaction is avoided, and the number of large molecular weight is reduced; reduces the introduction of oxygen content in water, improves the thermal stability of the PVC resin, and can produce high-quality PVC resin.)

1. A polymerization device for PVC resin is characterized by comprising a polymerization kettle, a cold water heating heat exchanger, a hot water constant temperature heat exchanger and a hot water tank, wherein the top of the polymerization kettle is provided with a first feed port, a second feed port, a water inlet, a high-pressure water inlet and a terminator port, the first feed port is connected with soft water, an initiator, a dispersant and a dispersant assistant pipeline, the second feed port is connected with a recovery and synthesis unit, and the high-pressure water inlet is connected with a high-pressure water and pressure transmitter; the water inlet is connected with a hot water tank; the terminator port is connected with the terminator groove through a terminator pipeline; a discharge hole and a high-pressure air inlet are formed in the bottom of the polymerization kettle, the discharge hole is connected with a discharge filter, the discharge filter leads to the settling tank, and the discharge filter is connected with a defoaming agent tank; the high-pressure air inlet is connected with high-pressure nitrogen and is provided with a safety valve;

the outer wall of the polymerization kettle is provided with a temperature control jacket, and the temperature control jacket is connected with a circulating water tank through a temperature control pipeline; the polymerization kettle is internally provided with a stirring device, a spraying device and an inner cooling pipe, the stirring device is arranged in the center of the polymerization kettle and is connected with a speed reduction motor, the spraying device is arranged at the upper part in the polymerization kettle and is connected with the kettle coating tank through a spraying pipeline, and the spraying pipeline is also connected with a steam pipe and a high-pressure water pipe; the inner cooling pipe is arranged on the inner side of the inner wall of the polymerization kettle and is connected with the cooling water tank;

the top of the hot water tank is provided with a constant temperature inlet, the bottom of the hot water tank is provided with a hot water outlet, the hot water outlet is branched into two pipelines which are respectively connected with a constant temperature circulating water pipe and a hot water feeding pipe, the constant temperature circulating water pipe is connected with the constant temperature inlet, and a constant temperature circulating pump and a hot water constant temperature heat exchanger are arranged on the constant temperature circulating water pipe; the hot water feeding pipe is connected with a water inlet of the polymerization kettle through a feeding hot water pump; the top of the hot water tank is also provided with a primary water inlet, the primary water inlet is connected with polymerization pure water through a primary water pipe, and the primary water pipe is provided with a cold water temperature-rising heat exchanger; the heat of the cold water temperature-rising heat exchanger and the heat of the hot water constant-temperature heat exchanger are both from hot steam and hot water generated by the polymerization kettle, and condensed water obtained after the hot steam and the hot water are cooled is led to the cooling water tank;

the top of the hot water tank is also provided with a nitrogen inlet, and the nitrogen of the nitrogen inlet is from nitrogen used for the polymerization kettle reaction; the bottom of the hot water tank is also provided with a sewage draining outlet which leads to a trench;

each hot water tank simultaneously supplies hot water required by polymerization reaction of one or more polymerization kettles.

2. The apparatus for polymerizing PVC resin according to claim 1, wherein the cooling water tank is further provided with a filler.

3. The apparatus for polymerizing PVC resin according to claim 1, wherein the top of the polymerizer is further provided with a ram tank, an explosion-proof safety valve, an auxiliary agent tank, and a main valve to which water, air, nitrogen gas, an evacuation line and a recovery line are connected.

4. The apparatus for polymerizing PVC resin according to claim 1, wherein the spray line, the temperature control line, the terminator line, the inlet line of the internal cooling pipe, the hot water feed pipe, and the outlet line of the defoaming agent tank are provided with a metering pump and a regulating valve.

5. The apparatus for polymerizing PVC resin according to claim 1, wherein a temperature sensor is provided in both of the hot water tank and the polymerizer.

6. A process for the synthesis of PVC resin using the apparatus according to any one of claims 1 to 5, comprising the following steps:

1) adding cold water into a polymerization kettle, adding the prepared initiator, dispersant and dispersion aid into the kettle, and controlling the temperature of the water in the polymerization kettle to be 18-20 ℃ after the water is added;

2) starting stirring, sending a set amount of monomers into a polymerization kettle, and after the monomers are added, carrying out cold stirring for 15-30 minutes;

3) after the cold stirring is finished, adding hot water with the temperature of 135 ℃ in a hot water tank obtained by heating and constant temperature into the polymerization kettle, wherein the adding ratio of the cold water to the hot water is 1.2-1.4: 1;

4) regulating the flow of steam introduced into the jacket of the polymerization kettle or cooling water introduced into an inner cooling pipe, regulating and controlling the temperature in the polymerization kettle, and starting polymerization reaction;

5) discharging through a discharge hole at the bottom of the polymerization kettle after the reaction is finished.

7. The synthesis method of PVC resin according to claim 6, wherein the hot water heating and constant temperature process comprises the following steps:

hot steam and hot polymerization water generated by a polymerization kettle are used for heating cold water for the first time through a cold water temperature rising heat exchanger to obtain primary water, wherein the temperature of the primary water is 50-70 ℃;

the primary water is sent to a hot water tank, the water in the hot water tank is heated to 100-135 ℃ through a hot water constant temperature heat exchanger, the temperature of the hot water is always kept through constant temperature circulation, and secondary water is obtained and then sent to a polymerization kettle.

Technical Field

The invention discloses a polymerization device and a polymerization method of PVC resin, and belongs to the technical field of PVC production.

Background

At present, 48m for polyvinyl chloride³The polymerizing pot feeding process adopts a 6-stage 48m suspension method polymerizing pot technology, a polymerizing feeding system adopts cold water feeding, the reaction period is long, and the average production time of 1 batch of PVC is about 480 min. The device is operated stably from 11 months in 2004 to 10 months in 2019, 14-15 kettles of PVC can be produced by 6 polymerization kettles per day under the normal production condition, the yield of each kettle is 13 tons, the yield of each kettle is about 190 plus 200 tons, and the maximum capacity of the device can reach 65000 tons.

The specific production steps are as follows: soft water is fed into a kettle (an auxiliary agent is fed into the kettle along with the soft water), a monomer is fed into the kettle, the temperature is raised (an initiator is decomposed), temperature control reaction is carried out, the reaction is terminated, discharging is carried out, and the wall is coated. This operation is repeated. Feeding cold water, raising the temperature by steam, beating soft water with the thickness of 21.5m into the kettle by a DCS control system, wherein the temperature of the soft water is 18-20 ℃, adding a prepared initiator, a dispersing agent, an auxiliary dispersing agent and the like into the kettle, after beating the water, starting stirring, sending a set amount of monomers into the polymerization kettle, after adding the monomers, performing cold stirring for 20 minutes, heating the circulating water by a steam injection jacket after the cold stirring is finished, heating the circulating water by the hot circulating water to control the temperature in the kettle, stopping raising the temperature, and ensuring that the temperature and the pressure of the reaction in the polymerization kettle are unchanged by adjusting the opening of a cold water adjusting valve in the reaction process.

However, the existing production process has the following problems: (1) in the prior art, the temperature is increased after the materials are fed, so that the temperature rise time is long and the energy consumption is large; (2) the polymerization temperature is almost the only factor determining the molecular weight of polyvinyl chloride resin, an initiator enters a polymerization kettle through cold and soft water in the existing feeding process, and when the cold water feeding is finished, vinyl chloride monomer is added into the polymerization kettle, the temperature of the polymerization kettle does not reach the set reaction temperature, and the vinyl chloride monomer starts to carry out polymerization reaction under the condition of being lower than the set reaction temperature due to the existence of the initiator, so that the molecular weight distribution width of a polyvinyl chloride resin product is increased, and the processability and the stability of a product of the polyvinyl chloride resin are deteriorated.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a PVC resin polymerization device and method, which can ensure stable operation conditions and stable reaction and can produce high-quality PVC resin.

The invention is realized by the following technical scheme:

a polymerization device for PVC resin comprises a polymerization kettle, a cold water heating heat exchanger, a hot water constant temperature heat exchanger and a hot water tank, wherein the top of the polymerization kettle is provided with a first feed inlet, a second feed inlet, a water inlet, a high-pressure water inlet and a terminator port, the first feed inlet is connected with a soft water pipeline, an initiator pipeline, a dispersing agent pipeline and a dispersing aid pipeline, the second feed inlet is connected with a recovery and synthesis unit, and the high-pressure water inlet is connected with a high-pressure water and pressure transmitter; the water inlet is connected with a hot water tank; the terminator port is connected with the terminator groove through a terminator pipeline; a discharge hole and a high-pressure air inlet are formed in the bottom of the polymerization kettle, the discharge hole is connected with a discharge filter, the discharge filter leads to the settling tank, and the discharge filter is connected with a defoaming agent tank; the high-pressure air inlet is connected with high-pressure nitrogen and is provided with a safety valve;

the outer wall of the polymerization kettle is provided with a temperature control jacket, and the temperature control jacket is connected with a circulating water tank through a temperature control pipeline; the polymerization kettle is internally provided with a stirring device, a spraying device and an inner cooling pipe, the stirring device is arranged in the center of the polymerization kettle and is connected with a speed reduction motor, the spraying device is arranged at the upper part in the polymerization kettle and is connected with the kettle coating tank through a spraying pipeline, and the spraying pipeline is also connected with a steam pipe and a high-pressure water pipe; the inner cooling pipe is arranged on the inner side of the inner wall of the polymerization kettle and is connected with the cooling water tank;

the top of the hot water tank is provided with a constant temperature inlet, the bottom of the hot water tank is provided with a hot water outlet, the hot water outlet is branched into two pipelines which are respectively connected with a constant temperature circulating water pipe and a hot water feeding pipe, the constant temperature circulating water pipe is connected with the constant temperature inlet, and a constant temperature circulating pump and a hot water constant temperature heat exchanger are arranged on the constant temperature circulating water pipe;

the hot water feeding pipe is connected with a water inlet of the polymerization kettle through a feeding hot water pump; the top of the hot water tank is also provided with a primary water inlet, the primary water inlet is connected with polymerization pure water through a primary water pipe, and the primary water pipe is provided with a cold water temperature-rising heat exchanger; the heat of the cold water temperature-rising heat exchanger and the heat of the hot water constant-temperature heat exchanger are both from hot steam and hot water generated by the polymerization kettle, and condensed water cooled by the hot steam and the hot water is led to the cooling water tank.

The top of the hot water tank is also provided with a nitrogen inlet, and the nitrogen of the nitrogen inlet is from nitrogen used for the polymerization kettle reaction. The bottom of the hot water tank is also provided with a drain outlet which leads to a trench.

Each hot water tank can simultaneously supply hot water required by polymerization reaction of a plurality of polymerization kettles;

preferably, the cooling water tank is further provided with a water filling port.

Preferably, the top of the polymerization kettle is also provided with a stamping tank, an explosion-proof safety valve, an auxiliary agent tank and a main valve, and the main valve is connected with water, air and nitrogen and is also connected with an evacuation pipeline and a recovery pipeline.

Preferably, the spraying pipeline, the temperature control pipeline, the terminator pipeline, the inlet pipeline of the inner cooling pipe, the hot water feeding pipe and the outlet pipeline of the defoaming agent tank are all provided with a metering pump and a regulating valve.

Preferably, temperature sensors are arranged in the hot water tank and the polymerization kettle.

A synthetic method of PVC resin comprises the following steps:

1) adding cold water into a polymerization kettle, adding the prepared initiator, dispersant and dispersion aid into the kettle, and controlling the temperature of the water in the polymerization kettle to be 18-20 ℃ after the water is added;

2) starting stirring, sending a set amount of monomers into a polymerization kettle, and after the monomers are added, carrying out cold stirring for 15-30 minutes;

3) after the cold stirring is finished, adding hot water in a hot water tank obtained by heating and constant temperature at the temperature of 100 ℃ and 135 ℃ into the polymerization kettle, wherein the adding ratio of cold water to hot water is 1.2-1.4: 1;

4) regulating the flow of steam introduced into the jacket of the polymerization kettle or cooling water introduced into an inner cooling pipe, regulating and controlling the temperature in the polymerization kettle, and starting polymerization reaction;

5) discharging through a discharge hole at the bottom of the polymerization kettle after the reaction is finished.

Preferably, the process of heating and maintaining the temperature of the hot water comprises the following steps:

hot steam and hot polymerization water generated by a polymerization kettle are used for heating cold water for the first time through a cold water temperature rising heat exchanger to obtain primary water, wherein the temperature of the primary water is 50-70 ℃;

the primary water is sent to a hot water tank, the water in the hot water tank is heated to 100-135 ℃ through a hot water constant temperature heat exchanger, the temperature of the hot water is always kept through constant temperature circulation, and secondary water is obtained and then sent to a polymerization kettle.

Compared with the prior art, the invention has the following beneficial effects:

1) after the polymerization feeding is finished, the temperature rise is not needed, the auxiliary time is greatly shortened, and the production efficiency of the polymerization kettle is improved; 2) low-temperature reaction is avoided, the number of large molecular weight is reduced, and the concentration of the molecular weight is improved; 3) the introduction of oxygen content in water is reduced, and the thermal stability of the PVC resin is improved.

Drawings

FIG. 1 is a schematic view of a polymerization apparatus according to the present invention;

FIG. 2 is a schematic view of the structure of the hot water tank of the present invention;

FIG. 3 is a schematic view showing the connection relationship between a hot water tank and a polymerizer in the present invention.

In the figure, 1 a polymerization kettle, 2 a cold water temperature-rising heat exchanger, 3 a hot water constant temperature heat exchanger, 4 a hot water tank, 11 a first feed inlet, 12 a second feed inlet, 13 a water inlet, 14 a high pressure water inlet, 15 a terminator port, 16 a soft water pipeline, 17 an initiator pipeline, 18 a dispersant pipeline, 19 an auxiliary dispersant pipeline, 20 a recovery unit, 21 a synthesis unit, 22 a high pressure water, 23 a pressure transmitter, 24 a terminator tank, 25 a discharge port, 26 a high pressure air inlet, 27 a discharge filter, 28 a precipitation tank, 29 a defoamer tank, 30 a high pressure nitrogen, 31 a temperature control jacket, 32 a circulating water tank, 33 a stirring device, 34 a spraying device, 35 an inner cooling pipe, 37 a coating kettle tank, 38 a steam pipe, 39 a high pressure water pipe, 40 a cooling water tank, 41 a constant temperature circulating water pipe, 42 a hot water feed pipe, 43 a hot water constant temperature heat exchanger, 44 a primary water pipe, 46 a stamping, 50 evacuation line, 51 recovery line, 52 constant temperature circulation pump, 53 drain.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the scope of the present invention is not limited to these examples, and all changes or equivalent substitutions that do not depart from the spirit of the present invention are intended to be included within the scope of the present invention.

Principle of PVC suspension polymerization

And finally, introducing a peroxide initiator into the VCM monomer dispersed phase to generate a reaction free radical to initiate the monomer to carry out addition polymerization. The reaction is exothermic reaction, the reaction heat is removed by cooling circulating water introduced into a kettle jacket, a terminator is added at the end point of the reaction to kill active free radicals to terminate the reaction, unreacted VCM in the polymerization kettle is recycled and enters a compressor to be pressurized for condensation and recycling, and the recycled VCM is used for the next secondary production.

A PVC resin polymerization device comprises a polymerization kettle 1, a cold water temperature-rising heat exchanger 2, a hot water constant-temperature heat exchanger 3 and a hot water tank 4, wherein the top of the polymerization kettle 1 is provided with a first feed port 11, a second feed port 12, a water inlet 13, a high-pressure water inlet 14 and a terminator port 15, the first feed port is connected with a soft water pipeline 16, an initiator pipeline 17, a dispersant pipeline 18 and a dispersant assistant pipeline 19, the second feed port 12 is connected with a recovery unit 20 and a synthesis unit 21, and the high-pressure water inlet 14 is connected with high-pressure water 22 and a pressure transmitter 23; the water inlet 13 is connected with the hot water tank 4; the terminator port 15 is connected with the terminator groove 24 through a terminator pipeline; a discharge hole 25 and a high-pressure air inlet 26 are formed in the bottom of the polymerization kettle 1, the discharge hole is connected with a discharge filter 27, the discharge filter leads to a precipitation tank 28, and the discharge filter 27 is connected with an antifoaming agent tank 29; the high-pressure gas inlet 26 is connected with high-pressure nitrogen 30 and is provided with a safety valve;

the outer wall of the polymerization kettle 1 is provided with a temperature control jacket 31, and the temperature control jacket is connected with a circulating water pool 32 through a temperature control pipeline; the polymerization kettle 1 is internally provided with a stirring device 33, a spraying device 34 and an inner cooling pipe 35, the stirring device is arranged in the center of the polymerization kettle and is connected with a speed reduction motor, the spraying device 34 is arranged at the inner upper part of the polymerization kettle and is connected with a kettle coating tank 37 through a spraying pipeline, and the spraying pipeline is also connected with a steam pipe 38 and a high-pressure water pipe 39; the inner cooling pipe 35 is arranged on the inner side of the inner wall of the polymerization kettle 1 and is connected with a cooling water tank 40;

the top of the hot water tank 4 is provided with a constant temperature inlet, the bottom of the hot water tank is provided with a hot water outlet, the hot water outlet is branched into two pipelines which are respectively connected with a constant temperature circulating water pipe 41 and a hot water feeding pipe 42, the constant temperature circulating water pipe 41 is connected with the constant temperature inlet, and the constant temperature circulating water pipe is provided with a constant temperature circulating pump 52 and a hot water constant temperature heat exchanger 3;

the hot water feeding pipe 42 is connected with the water inlet 13 of the polymerization kettle 1 through a feeding hot water pump 43; the top of the hot water tank 4 is also provided with a primary water inlet, the primary water inlet is connected with polymerization pure water through a primary water pipe 44, and the primary water pipe is provided with a cold water temperature-rising heat exchanger 2; the heat of the cold water temperature-rising heat exchanger 2 and the heat of the hot water constant-temperature heat exchanger 3 are both from hot steam and hot water generated by the polymerizer 1, and condensed water cooled by the hot steam and the hot water is led to the cooling water tank 40.

The top of the hot water tank is also provided with a nitrogen inlet, and the nitrogen of the nitrogen inlet is from nitrogen used for the polymerization kettle reaction. The bottom of the hot water tank is also provided with a drain outlet 53 which leads to a trench.

Each hot water tank 4 can simultaneously supply hot water required by polymerization reaction of a plurality of polymerization kettles 1;

the cooling water tank 40 is further provided with a water filling port.

The top of the polymerization kettle is also provided with a stamping tank 46, an explosion-proof safety valve 47, an auxiliary agent tank 48 and a main valve 49, wherein the main valve is connected with water, air and nitrogen, and is also connected with an evacuation pipeline 50 and a recovery pipeline 51.

And the spraying pipeline, the temperature control pipeline, the terminator pipeline, the inlet pipeline of the inner cooling pipe, the hot water feeding pipe and the outlet pipeline of the defoaming agent tank are respectively provided with a metering pump and an adjusting valve.

And temperature sensors are arranged in the hot water tank and the polymerization kettle.

A synthetic method of PVC resin comprises the following steps:

1) adding soft cold water into a polymerization kettle, adding the prepared initiator, dispersant and auxiliary dispersant into the kettle, and controlling the temperature of the water in the polymerization kettle to be 18-20 ℃ after the water is added;

2) starting stirring, sending a set amount of monomers into a polymerization kettle, and after the monomers are added, carrying out cold stirring for 20 minutes;

3) after the cold stirring is finished, adding hot soft water in a hot water tank obtained by heating and constant temperature at the temperature of 100 ℃ and 135 ℃ into the polymerization kettle, wherein the adding ratio of the cold water to the hot water is 1.2-1.4: 1;

the process of heating and keeping the temperature of the hot water comprises the following steps: hot steam and hot polymerization water generated by a polymerization kettle are used for heating cold water for the first time through a cold water temperature rising heat exchanger to obtain primary water, wherein the temperature of the primary water is 50-70 ℃; the primary water is sent to a hot water tank, the water in the hot water tank is heated to 100-135 ℃ through a hot water constant temperature heat exchanger, the temperature of the hot water is always kept through constant temperature circulation, and secondary water is obtained and then sent to a polymerization kettle.

4) Regulating the flow of steam introduced into the jacket of the polymerization kettle or cooling water introduced into an inner cooling pipe, regulating and controlling the temperature in the polymerization kettle, and starting polymerization reaction;

5) discharging through a discharge hole at the bottom of the polymerization kettle after the reaction is finished.