Hot water subsection control device and method for calcium carbide method polyvinyl chloride production converter

Abstract

The invention relates to the technical field of polyvinyl chloride production equipment, in particular to a hot water subsection control device and method for a calcium carbide method polyvinyl chloride production converter. The first-stage cooling assembly comprises a foreground conversion hot water tank, the output end of the foreground conversion hot water tank is connected with the cooling water outlet end of the first-stage converter through a first connecting pipe, and the output end of the foreground conversion hot water tank is sequentially connected with a first conveying pump assembly and a first hot water condenser. The output end of the first hot water condenser is connected with the cooling water inlet end of the first-section converter through a second connecting pipe. The method is beneficial to prolonging the service time of the catalyst and reducing the rebuilding frequency of the converter catalyst.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyvinyl chloride production equipment, in particular to a calcium carbide method polyvinyl chloride production converter hot water segmented control device and method. BACKGROUND

[0002] The production of polyvinyl chloride by the calcium carbide method is mainly through the reaction of calcium carbide with water to generate acetylene, which is then combined with hydrogen chloride to synthesize chloroethylene monomer, and finally polymerized to form PVC resin.

[0003] In the production process of calcium carbide method polyvinyl chloride, a set of hot water circulation system is used for heat exchange in the synthesis and conversion of chloroethylene. The hot water tank operates in a normal pressure environment, and the temperature of the hot water inside can reach up to 99℃. The main function of the hot water circulation system is to control the temperature during the reaction, so that the reaction can be carried out in an appropriate temperature range, thereby improving the reaction rate and conversion rate. Through hot water circulation, the heat generated during the reaction process can be effectively removed, maintaining the temperature balance of the reaction system. Although the use of low-mercury environmentally friendly catalysts has made progress in reducing mercury pollution, the mercury content still affects the conversion rate. When the catalyst is used for more than 7,000 hours, the conversion rate will show a significant downward trend. This is because the active components of the catalyst gradually deactivate during the long reaction process, and the active sites on the surface are covered or damaged, leading to a decrease in catalytic performance, which in turn affects the synthesis efficiency of chloroethylene.

[0004] In order to maintain a high conversion rate and ensure the stability of the production process and the reliability of the product quality, the converter needs to be extracted and flipped every month. The number of extraction and flipping is usually between 16-18 times. This operation not only increases the workload during the production process, but also causes the loss of catalyst to be more than 0.25 tons when each converter is extracted and flipped, which makes the unit consumption of catalyst relatively high and increases the production cost.

[0005] The frequent extraction and flipping of the catalyst means that the operator needs to regularly disassemble, clean and reload the equipment. This process involves complex operation steps and high labor intensity, and also requires proper handling and management of the catalyst to avoid waste of the catalyst and potential pollution risks to the environment. In addition, frequent catalyst extraction and flipping may also have some impact on the service life of the converter, increasing the cost of equipment maintenance and replacement.

[0006] Therefore, the skilled person in the art is committed to developing a calcium carbide method polyvinyl chloride production converter hot water segmented control device and method to extend the service life of the catalyst and reduce the frequency of converter catalyst repair. SUMMARY

[0007] The technical problem solved by the present application is to provide a calcium carbide method PVC production converter hot water segmented control device and method, which prolongs the service life of the catalyst and reduces the catalyst overhaul frequency. The technical scheme for solving the above technical problem is as follows: A calcium carbide method PVC production converter hot water segmented control device comprises a primary cooling assembly and a secondary cooling assembly. The primary cooling assembly comprises a front-stage conversion hot water tank, the output end of the front-stage conversion hot water tank is connected with the outlet end of a first-stage converter cooling water through a first connecting pipe, the output end of the front-stage conversion hot water tank is sequentially connected with a first conveying pump assembly and a first hot water condenser, and the output end of the first hot water condenser is connected with the inlet end of the first-stage converter cooling water through a second connecting pipe. The secondary cooling assembly comprises an oxygen removal tower and a back-stage conversion hot water tank, the input end of the oxygen removal tower is connected with the outlet end of a second-stage converter cooling water through a third connecting pipe, the oxygen removal tower is installed on the back-stage conversion hot water tank, the output end of the back-stage conversion hot water tank is sequentially connected with a second conveying pump assembly and a second hot water condenser, and the output end of the second hot water condenser is connected with the inlet end of the second-stage converter cooling water through a fourth connecting pipe.

[0008] The beneficial effects of the above scheme are as follows: the cooling water circulation systems of the first-stage converter and the second-stage converter are processed in a segmented manner through the primary cooling assembly and the secondary cooling assembly. The primary cooling assembly utilizes the front-stage conversion hot water tank, the first conveying pump assembly and the first hot water condenser and the like to preliminarily cool and control the circulation of the cooling water of the first-stage converter; the secondary cooling assembly utilizes the oxygen removal tower, the back-stage conversion hot water tank, the second conveying pump assembly and the second hot water condenser and the like to further process and control the circulation of the cooling water of the second-stage converter. The segmented hot water circulation cooling manner can more accurately meet the cooling water temperature and pressure requirements of different converter stages, improve the overall efficiency and stability of the hot water circulation system, thereby more favorably maintaining the suitability of the reaction temperature in the calcium carbide method PVC production process, and further helping to improve the reaction rate and conversion rate and guarantee the product quality.

[0009] On the basis of the above technical scheme, the present application can be further improved as follows.

[0010] Further, the front-stage conversion hot water tank and the back-stage conversion hot water tank are both connected with a desalted water pipe and a low-pressure steam pipe.

[0011] The beneficial effect of the above further scheme is that the front-stage conversion hot water tank and the back-stage conversion hot water tank are both connected to the desalted water pipe and the low-pressure steam pipe, which is conducive to desalination treatment of the water in the hot water tank and adjustment of the temperature, pressure and other parameters of the water in the hot water tank, further improves the water quality and water temperature control precision of the hot water circulating system, is conducive to prolonging the service life of the equipment, and at the same time more accurately meets the requirements of different conversion stages for hot water parameters, improves the performance of the entire hot water segmented control device, and better guarantees the stability and quality of the production of polyvinyl chloride by the calcium carbide method.

[0012] Further, the deoxygenation tower comprises a tower body, the bottom of the tower body is communicated with the back-stage conversion hot water tank, and the first deoxygenation assembly, the second deoxygenation assembly and the third deoxygenation assembly are sequentially installed in the tower body from top to bottom.

[0013] The beneficial effect of the above further scheme is that the deoxygenation tower is installed on the back-stage conversion hot water tank, and the first deoxygenation assembly, the second deoxygenation assembly and the third deoxygenation assembly are sequentially installed in the tower body from top to bottom, and the multi-stage deoxygenation structure can fully remove oxygen and other gases in the cooling water of the two-stage converter.

[0014] Further, the first deoxygenation assembly comprises a first deoxygenation chamber and a second deoxygenation chamber, the first deoxygenation chamber is communicated with the third connecting pipe and installed in the tower body, a plurality of deoxygenation pipes are installed in the first deoxygenation chamber, the deoxygenation pipes are provided with a plurality of spaced liquid inlet holes, and the liquid inlet holes are obliquely arranged so that water film is formed in the deoxygenation pipes from the cooling water in the first deoxygenation chamber entering the deoxygenation pipes through the liquid inlet holes. The second deoxygenation chamber is installed in the tower body and communicated with the steam pipe, the lower side of the deoxygenation pipe is located in the second deoxygenation chamber, and the end of the deoxygenation pipe extends out of the lower end of the second deoxygenation chamber, the lower side of the deoxygenation pipe is provided with an air inlet hole, and the air inlet hole is obliquely arranged so that the steam in the second deoxygenation chamber enters the deoxygenation pipe to mix with the brine and is discharged.

[0015] The beneficial effect of the above further scheme is that the first deoxygenation chamber in the first deoxygenation assembly is communicated with the cooling water and the deoxygenation pipes with obliquely arranged and spaced liquid inlet holes, so that the cooling water enters the deoxygenation pipes to form water film, and the second deoxygenation chamber is communicated with the steam pipe, and the lower side of the deoxygenation pipe is provided with an oblique air inlet hole to let the steam enter to mix with the brine and be discharged. On the one hand, the formation of water film and the mixing of steam and brine can effectively remove dissolved oxygen in the cooling water, improve the deoxygenation effect; on the other hand, the obliquely arranged liquid inlet holes and air inlet holes help to optimize the flow path of liquid and gas, so that the deoxygenation process is more sufficient and efficient, thereby further guaranteeing the water quality of the hot water circulating system, reducing the adverse effects of oxygen content on equipment and reactions, and improving the operation stability and production efficiency of the entire device.

[0016] Further, the second oxygen removal assembly comprises a high-pressure steam pipe installed in the middle of the tower body, the high-pressure steam pipe is provided with a plurality of steam outlets, and the steam outlets are upwardly arranged so that the steam sprayed from the steam outlets forms a convection heat exchange with the brine flowing from the first oxygen removal assembly.

[0017] The beneficial effect of the above further scheme is that the high-pressure steam pipe of the second oxygen removal assembly is installed in the middle of the tower body and provided with upwardly arranged steam outlets, so that the sprayed steam forms a convection heat exchange with the brine flowing from the first oxygen removal assembly, which allows sufficient heat exchange between the steam and the brine. On the one hand, it helps to increase the temperature of the brine, so as to achieve better oxygen removal effect (because the increase of temperature helps to separate the gas from the solution), and on the other hand, it makes full use of the heat of the steam, improves the utilization rate of energy, reduces the production cost, further improves the oxygen removal performance of the entire oxygen removal tower, guarantees the water quality and operation effect of the hot water circulation system, and also allows the backstage conversion hot water tank to maintain a suitable pressure, so that the cooling water in the backstage conversion hot water tank can exceed one hundred degrees Celsius without boiling.

[0018] Further, the third oxygen removal assembly comprises an oxygen removal plate and a filler layer; the oxygen removal plate is provided with a water leakage hole, and an ultrasonic generator is installed in the oxygen removal plate. The filler layer is arranged on the lower side of the oxygen removal plate.

[0019] The beneficial effect of the above further scheme is that the oxygen removal plate of the third oxygen removal assembly is provided with a water leakage hole and an ultrasonic generator, and the lower side is provided with a filler layer. The water leakage hole of the oxygen removal plate can uniformly distribute the brine, so that the brine interacts with the ultrasonic waves generated by the ultrasonic generator. The ultrasonic waves can make the bubbles in the brine oscillate and break, thereby effectively separating the oxygen and other gases dissolved in the brine. At the same time, the filler layer can increase the separation contact area of the brine and the gas, further improving the oxygen removal efficiency. The cooling water after multi-stage oxygen removal has a lower oxygen content, which can better meet the water quality requirements of the secondary reformer cooling water, reduce the corrosion of equipment and the influence on the reaction, and improve the reliability and production quality of the device.

[0020] Further, an exhaust pipe is installed on the upper end of the tower body, and a gas-liquid separator and a back pressure valve are installed on the exhaust pipe.

[0021] The beneficial effect of the above further scheme is that the exhaust pipe with the gas-liquid separator and the back pressure valve is installed on the upper end of the tower body. The gas-liquid separator can effectively separate the gas and liquid in the exhaust gas, prevent the liquid from being discharged with the gas to cause waste and safety hazards, and at the same time, the back pressure valve can adjust the pressure in the exhaust pipe, maintain the stability of the pressure in the oxygen removal tower, ensure the smooth progress of the oxygen removal process, improve the oxygen removal effect and the operation stability of the entire hot water section control device, and is conducive to guaranteeing the continuity and quality of the production of polyvinyl chloride by the calcium carbide method.

[0022] A calcium carbide method PVC production converter hot water section control method applied to the calcium carbide method PVC production converter hot water section control device as described above, comprising the following steps: S10. The outlet cooling water of the first-stage converter sequentially passes through the first connecting pipe, the front-stage conversion hot water tank, the first delivery pump assembly to the first hot water condenser, so that the cooling water discharged from the first hot water condenser has a temperature of 95-99 DEG C, and the pressure in the front-stage conversion hot water tank is normal pressure; S20. The outlet cooling water of the second-stage converter sequentially passes through the third connecting pipe, the deaerator tower, the back-stage conversion hot water tank, the second delivery pump assembly to the second hot water condenser, so that the cooling water discharged from the second hot water condenser has a temperature of 110-120 DEG C, and the pressure in the back-stage conversion hot water tank is 0.16-0.2 MPa.

[0023] The beneficial effects of the above further scheme are: through the outlet cooling water of the first-stage converter sequentially passing through the first connecting pipe, the front-stage conversion hot water tank, the first delivery pump assembly to the first hot water condenser, so that the cooling water discharged has a temperature of 95-99 DEG C and the pressure in the hot water tank is normal pressure, and through the outlet cooling water of the second-stage converter sequentially passing through the relevant components, the cooling water discharged has a temperature of 110-120 DEG C and the pressure in the hot water tank is 0.16-0.2 MPa, the hot water section control method can accurately control the temperature and pressure parameters of the cooling water at different converter stages; On the one hand, the cooling water of the first-stage converter is maintained at a suitable higher temperature range under normal pressure, satisfying the heat balance and temperature conditions required by the reaction; On the other hand, the cooling water of the second-stage converter is raised in temperature under a certain pressure, better adapting to the characteristics and requirements of the second-stage conversion reaction, further optimizing the heat exchange effect and reaction condition control of the entire hot water circulation system, prolonging the service life of the catalyst, reducing the catalyst repair frequency, reducing the production cost, and improving the stability of the calcium carbide method PVC production process and the product quality. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a first-stage cooling assembly structure schematic view of a specific embodiment of the present application; Figure 2 It is a second-stage cooling assembly structure schematic view of a specific embodiment of the present application; Figure 3 It is a deaerator tower structure schematic view of a specific embodiment of the present application.

[0025] In the drawings, the components represented by each reference numeral are listed as follows: 100, primary cooling assembly; 110, front-stage conversion hot water tank; 111, first connecting pipe; 120, first delivery pump assembly; 130, first hot water condenser; 131, second connecting pipe; 200, secondary cooling assembly; 210, deaerating tower; 211, third connecting pipe; 212, tower body; 213, first deaerating chamber; 214, second deaerating chamber; 215, deaerating pipe; 216, steam pipe; 217, high-pressure steam pipe; 218, deaerating plate; 219, filler layer; 2110, ultrasonic generator; 2111, exhaust pipe; 2112, gas-liquid separator; 2113, back pressure valve; 220, back-stage conversion hot water tank; 230, second delivery pump assembly; 240, second hot water condenser; 241, fourth connecting pipe. DETAILED DESCRIPTION

[0026] The principles and features of the present application are described below in conjunction with the accompanying drawings, in which the examples are presented only to explain the present application and are not intended to limit the scope of the present application.

[0027] In the description of the present application, it should be understood that the terms "center", "length", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "inner", "outer", "peripheral side", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the system or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0028] In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0029] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0030] As shown in Figure 1 , Figure 2 and Figure 3 , a hot water section control device for calcium carbide method polyvinyl chloride production converter, comprising a primary cooling assembly 100 and a secondary cooling assembly 200; The primary cooling assembly 100 comprises a front-stage conversion hot water tank 110, and the output end of the front-stage conversion hot water tank 110 is connected with the cooling water outlet end of the first-stage converter through a first connecting pipe 111, so that the high-temperature cooling water generated by the first-stage converter in the production process can flow into the front-stage conversion hot water tank 110 smoothly, and the cooling water flowing out of the cooling water outlet end of the first-stage converter enters the front-stage conversion hot water tank 110 with the heat absorbed in the chemical reaction process, at this time, the temperature of the hot water is relatively high, and the pressure is normal pressure. The output end of the front-stage conversion hot water tank 110 is connected with a first conveying pump assembly 120 and a first hot water condenser 130 in sequence, and the high-temperature cooling water in the hot water tank is conveyed into the first hot water condenser 130 by the power provided by the first conveying pump assembly 120. In the first hot water condenser 130, the temperature of the cooling water is lowered by heat exchange with the external heat exchange medium (such as circulating air or other cooling medium), so that the temperature of the cooling water flowing out of the first hot water condenser 130 can be stably controlled in the suitable interval of 95-99℃, which can not only meet the temperature requirement of the subsequent cooling cycle of the first-stage converter, but also ensure the stability of the physical properties of the hot water at normal pressure, so as to facilitate the recycling. The output end of the first hot water condenser 130 is connected with the cooling water inlet end of the first-stage converter through a second connecting pipe 131, and then the cooling water treated by the temperature reduction is returned to the cooling water inlet end of the first-stage converter through the second connecting pipe 131, to complete the one-cycle process of the cooling water of the first-stage converter. The circulation can effectively maintain the temperature balance in the first-stage converter, ensure the chemical reaction in the first-stage converter to be carried out in a suitable temperature environment, and thus improve the reaction efficiency and product quality.

[0031] The secondary cooling assembly 200 comprises an oxygen removal tower 210 and a back-stage conversion hot water tank 220, and the front-stage conversion hot water tank 110 and the back-stage conversion hot water tank 220 are both connected with a desalted water pipe 112 and a low-pressure steam pipe 113. The desalted water pipe 112 can supplement the desalted water to the hot water tank when needed, and the desalted water has a lower content of impurity ions, which can help to prevent corrosion and scaling in the hot water circulating system due to the high concentration of impurity ions, prolong the service life of the equipment, and ensure the water quality purity of the hot water circulating system and improve the heat exchange efficiency and operation stability of the whole system. The low-pressure steam pipe 113 is used to adjust the temperature of the water in the hot water tank under certain working conditions. When the temperature of the water in the hot water tank deviates from the set range due to the change of the ambient temperature or the fluctuation of the heat load in the production process, the temperature of the water in the hot water tank can be accurately adjusted by controlling the inflow amount of the low-pressure steam, so as to ensure that the hot water circulating system is always in the best working temperature range.

[0032] The input end of the oxygen removal tower 210 is connected with the output end of the second-stage converter cooling water through a third connecting pipe 211. The oxygen removal tower 210 is installed on a back-stage conversion hot water tank 220. The output end of the back-stage conversion hot water tank 220 is sequentially connected with a second delivery pump assembly 230 and a second hot water condenser 240. The output end of the second hot water condenser 240 is connected with the input end of the second-stage converter cooling water through a fourth connecting pipe 241.

[0033] As shown in Figure 2 , Figure 3 In some embodiments, the oxygen removal tower 210 includes a tower body 212. The bottom of the tower body 212 is communicated with the back-stage conversion hot water tank 220. A first oxygen removal assembly, a second oxygen removal assembly and a third oxygen removal assembly are sequentially installed in the tower body 212 from top to bottom, so as to realize multi-stage and efficient removal of impurity gases such as oxygen in the cooling water.

[0034] In the embodiments, the first oxygen removal assembly includes a first oxygen removal chamber 213 and a second oxygen removal chamber 214. The first oxygen removal chamber 213 is communicated with the third connecting pipe 211 and is installed in the tower body 212. A plurality of oxygen removal pipes 215 are installed in the first oxygen removal chamber 213. The oxygen removal pipes 215 are provided with a plurality of liquid inlet holes which are arranged at intervals and are obliquely arranged so that the cooling water in the first oxygen removal chamber 213 enters the oxygen removal pipes 215 to form a water film. When the high-temperature cooling water of the second-stage converter enters the first oxygen removal chamber 213 through the third connecting pipe 211, it flows into the plurality of oxygen removal pipes 215 installed in the first oxygen removal chamber 213. The oxygen removal pipes 215 are uniformly distributed with a plurality of liquid inlet holes which are arranged at intervals and are obliquely arranged at an angle of 5° to 30°, so that the cooling water in the first oxygen removal chamber 213 enters the oxygen removal pipes 215 at a certain flow rate and angle, and forms a uniform water film on the inner wall of the pipes. The water film has a large surface area, which is beneficial to the diffusion of oxygen and other gas molecules dissolved in the water to the surface of the water film, thereby realizing the preliminary separation of the gas and the water.

[0035] The second oxygen removal chamber 214 is installed in the tower body 212 and is communicated with a steam pipe 216. The lower side of the oxygen removal pipes 215 is located in the second oxygen removal chamber 214 and the end of the oxygen removal pipes 215 extends out of the lower end of the second oxygen removal chamber 214. The lower side of the oxygen removal pipes 215 is provided with an air inlet hole which is obliquely arranged so that the steam in the second oxygen removal chamber 214 enters the oxygen removal pipes 215 and is mixed with the brine and discharged.

[0036] The second oxygen removal chamber 214 is installed in the tower body 212 and communicates with the steam pipe 216. Steam in the steam pipe 216 is introduced into the second oxygen removal chamber 214, and the lower side of the oxygen removal pipe 215 is just within the space range of the second oxygen removal chamber 214, and the end of the oxygen removal pipe 215 extends out of the lower end of the second oxygen removal chamber 214. A gas inlet hole inclined in the same way is also arranged on the lower side of the oxygen removal pipe 215. The inclined gas inlet hole enables the steam in the second oxygen removal chamber 214 to smoothly enter the oxygen removal pipe 215 under the action of the pressure difference and mix with the water film in the pipe. When the steam contacts the water film, the heat of the steam is transferred to the water film, which increases the temperature of the water film. This helps to further reduce the solubility of the dissolved gas in the water, causing more gas to be precipitated from the water. At the same time, the flow of steam also plays a stirring role, enhancing the renewal of the water film and the escape speed of the gas, thereby achieving deep removal of dissolved oxygen in the cooling water.

[0037] In the embodiment, the second oxygen removal assembly includes a high-pressure steam pipe 217 installed in the middle of the tower body 212. The high-pressure steam pipe 217 has a plurality of steam outlet holes facing upward, so that the steam sprayed from the steam outlet holes forms a countercurrent heat exchange with the brine flowing down from the first oxygen removal assembly. When the steam is sprayed from the steam outlet holes of the high-pressure steam pipe 217, it forms a countercurrent heat exchange with the brine (cooling water after preliminary oxygen removal) flowing down from the first oxygen removal assembly. On the one hand, the heat of the steam is transferred to the brine, further increasing the temperature of the brine. The increase in temperature greatly reduces the solubility of the remaining dissolved gas in the brine, thereby forcing more gas to be precipitated from the brine, achieving the purpose of further oxygen removal. On the other hand, this countercurrent heat exchange method fully utilizes the high-temperature heat energy of the steam, improves the energy utilization efficiency, reduces the energy consumption in the production process, and also provides more favorable temperature conditions for the subsequent oxygen removal process.

[0038] The third oxygen removal assembly comprises an oxygen removal plate 218 and a filler layer 219; the oxygen removal plate 218 has water leakage holes, an ultrasonic generator 2110 is installed in the oxygen removal plate 218, and the filler layer 219 is located on the lower side of the oxygen removal plate 218. When the brine after passing through the first two stages of oxygen removal flows down from above the oxygen removal plate 218, the brine is uniformly distributed on the oxygen removal plate 218 through the water leakage holes. At this time, the ultrasonic waves generated by the ultrasonic generator 2110 propagate in the brine, and the high-frequency vibration of the ultrasonic waves generates a large number of micro-bubbles in the brine, which continuously oscillate and break during the vibration process, generating strong shearing force and peeling effect on the dissolved oxygen and other gases in the brine, so that the gases are more easily separated from the brine. At the same time, the filler layer 219 located on the lower side of the oxygen removal plate 218 provides a large gas-liquid contact area, and when the gas is separated out from the brine, it will pass through the filler layer 219. The special structure of the filler layer 219 can prolong the residence time of the gas in the brine, promote the thoroughness of gas-liquid separation, and further improve the oxygen removal efficiency, so as to ensure that the oxygen content in the cooling water flowing into the back-end conversion hot water tank 220 reaches an extremely low level, meet the strict water quality requirements of the secondary reformer cooling water, effectively reduce the equipment corrosion and adverse effects on chemical reactions caused by dissolved oxygen, and improve the operation reliability of the entire production device and the quality stability of the product.

[0039] An exhaust pipe 2111 is also installed on the upper end of the tower body 212, and a gas-liquid separator 2112 and a back pressure valve 2113 are installed on the exhaust pipe 2111. The main function of the gas-liquid separator 2112 is to effectively separate the trace amount of liquid that may be entrained when the gas (mainly oxygen and other trace amount of impurity gas) generated in the oxygen removal process is discharged, so as to prevent the liquid from being discharged together with the gas and to avoid waste of water resources and possible safety hazards. The back pressure valve 2113 is used to adjust the pressure in the exhaust pipe, and by accurately controlling the opening degree of the back pressure valve, the stability of the pressure in the oxygen removal tower can be maintained.

[0040] The application also provides a calcium carbide method PVC production converter hot water segmented control method, which is applied to the calcium carbide method PVC production converter hot water segmented control device as described above, and comprises the following steps: S10. The outlet cooling water of the first-stage converter sequentially passes through the first connecting pipe 111, the front-stage conversion hot water tank 110, the first delivery pump assembly 120, and the first hot water condenser 130, so that the temperature of the cooling water discharged from the first hot water condenser 130 is 95-99°C, and the pressure in the front-stage conversion hot water tank 110 is normal pressure. On the one hand, it can meet the requirement of the first-stage converter on the temperature of the cooling water in the chemical reaction process, ensure that the heat generated in the reaction is removed in time and effectively, and maintain the suitability of the internal reaction temperature of the first-stage converter. Since the reaction in the first-stage converter is intense, the stability of the reaction rate and the conversion rate is ensured. On the other hand, the temperature range also balances the operation efficiency and energy consumption of the hot water circulation system, avoids the increase of energy consumption due to the excessive cooling water circulation caused by too low temperature, prevents the problems such as water vaporization caused by too high temperature, and ensures the efficient and stable operation of the entire first-stage converter cooling water circulation system. The cooling water after the temperature reduction is finally returned to the inlet end of the first-stage converter cooling water through the second connecting pipe 131, and a complete cooling water circulation process is completed, so as to continuously provide stable cooling effect for the first-stage converter and maintain the stability of the internal reaction environment of the first-stage converter.

[0041] S20. The outlet cooling water of the second-stage converter sequentially passes through the third connecting pipe 211, the deaerator tower 210, the back-stage conversion hot water tank 220, the second delivery pump assembly 230, and the second hot water condenser 240, so that the temperature of the cooling water discharged from the second hot water condenser 240 is 110-120°C, and the pressure in the back-stage conversion hot water tank 220 is 0.16-0.2 MPa.

[0042] In the specific process, the cooling water in the deaerator 210 is subjected to a multi-stage deaeration process to remove dissolved oxygen and other impurity gases from the cooling water. After deaeration, the cooling water flows through the background conversion hot water tank 220, where it is temporarily stored and mixed with other treated cooling water. The pressure in the background conversion hot water tank 220 is controlled between 0.16 MPa and 0.2 MPa. This pressure range is determined based on the process requirements of the secondary reformer and the physical characteristics of the hot water circulation system. Higher pressure helps maintain the cooling water in a liquid state during subsequent circulation and heating to a temperature range of 110°C to 120°C in the second hot water condenser 240 without vaporization, which is crucial for meeting the high temperature requirements of the secondary reformer internal reaction and ensuring the heat exchange efficiency of the cooling water circulation system. Then, the cooling water in the background conversion hot water tank 220 is sent to the second hot water condenser 240 under the transport action of the second delivery pump assembly 230. In the second hot water condenser 240, the cooling water exchanges heat with a high-temperature heat source, and its temperature rises to 110°C to 120°C after absorbing heat. This temperature range is selected considering the reaction characteristics of the calcium carbide method PVC production process in the secondary reformer. Since the reaction in the secondary reformer is stable, higher temperature can increase the reaction rate, and higher temperature can better adapt to the heat conditions required by the secondary reforming reaction, further optimizing the heat exchange effect of the entire hot water circulation system, ensuring that the chemical reaction inside the secondary reformer proceeds efficiently in a suitable temperature environment, thereby improving product quality and production efficiency. Finally, the cooling water after temperature rise is returned to the secondary reformer cooling water inlet end through the fourth connecting pipe 241, completing the cooling water circulation process in the secondary reformer, providing stable cooling and heat regulation for the secondary reformer, and ensuring the smooth progress of the entire calcium carbide method PVC production process.

[0043] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, different embodiments or examples described in the present specification and the features of different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0044] The above merely describes preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A hot water segment control device for a converter in the calcium carbide-based polyvinyl chloride production process, characterized in that: Includes a primary cooling assembly (100) and a secondary cooling assembly (200); The primary cooling assembly (100) includes a front-end conversion hot water tank (110), the output end of which is connected to the cooling water outlet of a first-stage converter via a first connecting pipe (111), the output end of which is sequentially connected to a first delivery pump assembly (120) and a first hot water condenser (130), and the output end of the first hot water condenser (130) is connected to the cooling water inlet of a first-stage converter via a second connecting pipe (131). The secondary cooling assembly (200) includes a deaerator (210) and a back-end conversion hot water tank (220). The input end of the deaerator (210) is connected to the cooling water outlet of the second-stage converter through a third connecting pipe (211). The deaerator (210) is installed on the back-end conversion hot water tank (220). The output end of the back-end conversion hot water tank (220) is sequentially connected to a second delivery pump assembly (230) and a second hot water condenser (240). The output end of the second hot water condenser (240) is connected to the cooling water inlet of the second-stage converter through a fourth connecting pipe (241).

2. The hot water segment control device for the calcium carbide-based polyvinyl chloride production converter according to claim 1, characterized in that: Both the front-end hot water conversion tank (110) and the back-end hot water conversion tank (220) are connected to a desalination pipe (112) and a low-pressure steam pipe (113).

3. The hot water segment control device for the calcium carbide-based polyvinyl chloride production converter according to claim 1, characterized in that: The deoxygenation tower (210) includes a tower body (212), the bottom of which is connected to the back-end conversion hot water tank (220). The tower body (212) is equipped with a first deoxygenation component, a second deoxygenation component and a third deoxygenation component in sequence from top to bottom.

4. The hot water segment control device for the calcium carbide-based polyvinyl chloride production converter according to claim 3, characterized in that: The first deoxygenation assembly includes a first deoxygenation chamber (213) and a second deoxygenation chamber (214). The first deoxygenation chamber (213) is connected to the third connecting pipe (211) and installed in the tower body (212). A plurality of deoxygenation pipes (215) are installed in the first deoxygenation chamber (213). The deoxygenation pipes (215) have a plurality of spaced liquid inlet holes and the liquid inlet holes are inclined so that the cooling from the first deoxygenation chamber (213) enters the deoxygenation pipes (215) through the liquid inlet holes to form a water film. The second deoxygenation chamber (214) is installed inside the tower body (212) and is connected to the steam pipe (216). The lower side of the deoxygenation pipe (215) is located inside the second deoxygenation chamber (214) and the end of the deoxygenation pipe (215) extends out of the lower end of the second deoxygenation chamber (214). An air inlet is provided on the lower side of the deoxygenation pipe (215). The air inlet is inclined so that the steam in the second deoxygenation chamber (214) enters the deoxygenation pipe (215) and mixes with the brine before being discharged.

5. The hot water segment control device for the calcium carbide-based polyvinyl chloride production converter according to claim 4, characterized in that: The second deoxygenation component includes a high-pressure steam pipe (217), which is installed in the middle of the tower body (212). The high-pressure steam pipe (217) has multiple steam outlet holes and the steam outlet holes face upwards, so that the steam ejected from the steam air holes forms a convective heat exchange with the brine flowing down from the first deoxygenation component.

6. The hot water segment control device for the calcium carbide-based polyvinyl chloride production converter according to claim 4, characterized in that: The third deoxygenation component includes a deoxygenation plate (218) and a packing layer (219); the deoxygenation plate (218) has a water leakage hole, and an ultrasonic generator (2110) is installed inside the deoxygenation plate (218). The packing layer (219) is located below the deaerator plate (218).

7. The hot water segment control device for the calcium carbide-based polyvinyl chloride production converter according to claim 4, characterized in that: The upper end of the tower body (212) is also equipped with an exhaust pipe (2111), on which a gas-liquid separator (2112) and a back pressure valve (2113) are installed.

8. A method for segmented control of hot water in a converter for calcium carbide-based polyvinyl chloride (PVC) production, applied to the segmented control device for hot water in a converter for calcium carbide-based PVC production as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S10. The outlet cooling water of the first converter passes through the first connecting pipe (111), the front-end conversion hot water tank (110), the first delivery pump assembly (120) to the first hot water condenser (130) in sequence, so that the temperature of the cooling water discharged from the first hot water condenser (130) is 95°C to 99°C, and the pressure in the front-end conversion hot water tank (110) is atmospheric pressure. S20. The outlet cooling water of the two-stage converter passes sequentially through the third connecting pipe (211), the deaerator (210), the back-end conversion hot water tank (220), and the second transfer pump assembly (230) to the second hot water condenser (240), so that the temperature of the cooling water discharged from the second hot water condenser (240) is 110°C to 120°C, and the pressure in the back-end conversion hot water tank (220) is 0.16Mpa to 0.2Mpa.

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