Device for producing byproduct steam through heat removal conversion of PVC heptane by calcium carbide method

Abstract

The utility model provides a device for heat removal and conversion of PVC (polyvinyl chloride) heptane by a calcium carbide method to generate byproduct steam, which belongs to the technical field of chemical energy conservation and consumption reduction and comprises a hot water tank, a conversion hot water cooler, a conversion refrigerant condenser, a flash tank and a heat energy utilization system. After hot water in the hot water tank is subjected to heat exchange through the conversion hot water cooler and the conversion refrigerant condenser, one part of the hot water flows back into the hot water tank, the other part of the hot water enters the flash tank, saturated water in the flash tank flows back to the hot water tank after flash evaporation, and steam in the flash tank enters the heat energy utilization system for heat exchange to generate condensate water. And then the water flows back into the hot water tank. According to the utility model, heat loss can be avoided, the energy utilization rate is improved, and serious oxygen corrosion of equipment and pipelines can be avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical energy saving and consumption reduction, and particularly relates to a device for heat removal and conversion of by-product steam of PVC heptane by calcium carbide process. Background Art

[0002] As an important basic chemical raw material, vinyl chloride is widely used in many industries such as chemical industry, building materials, plastics, etc. The production process of vinyl chloride consumes a lot of energy. In order to improve the energy utilization efficiency of vinyl chloride production and reduce energy consumption, it is of great significance to carry out energy conservation and consumption reduction research on vinyl chloride equipment.

[0003] In the production process of PVC by calcium carbide method, a large amount of heat is released during the synthesis of vinyl chloride. There are usually two ways to remove heat in the industry, one is to use hot water to remove heat, and the other is to use heptane-hot water to remove heat. The heat removed by hot water is mostly used for vinyl chloride distillation and lithium bromide refrigeration. In this process, there are the following problems:

[0004] The hot water return temperature is high, and most of the hot water tanks in the industry are atmospheric pressure containers and are not closed. There is a lot of steam escaping into the atmosphere, which is wasteful. In addition, due to the open design, the deoxidation effect is poor, causing serious oxygen corrosion of equipment and pipelines.

[0005] The hot water return temperature is too high, the steam and water are mixed, and the return pipe has a "water hammer" phenomenon, which causes large vibration and frequent leakage in the return pipe, posing a safety risk. In order to solve the water hammer phenomenon, the upper return water is connected in series to reduce the return water temperature and increase the return water pressure, but in this process, there is also heat loss.

[0006] When the hot water in the hot water tank is sent out through the hot water pump, it exchanges heat with the circulating water to reduce the hot water temperature. This process increases the circulating water load and results in heat loss.

[0007] The utilization efficiency of waste heat from hot water is not as high as that of directly producing steam. Utility Model Content

[0008] In view of the problems existing in the above-mentioned prior art, the utility model provides a device for removing heat from heptane of PVC produced by the calcium carbide process and converting by-product steam. The technical problem to be solved by the utility model is how to avoid heat loss, improve energy utilization, and at the same time avoid serious oxygen corrosion of equipment and pipelines.

[0009] In order to solve the above technical problems, the utility model provides a device for heat removal and conversion of by-product steam of PVC heptane by calcium carbide process, comprising a hot water tank, a conversion hot water cooler, a conversion refrigerant condenser, a flash tank and a heat energy utilization system;

[0010] The water outlet of the hot water tank is connected to the conversion hot water cooler, the water outlet of the conversion hot water cooler is connected to the conversion refrigerant condenser, the water outlet of the conversion refrigerant condenser is connected to the water inlets of the hot water tank and the flash tank, the bottom of the flash tank is connected to the water inlet of the hot water tank, the top of the flash tank is connected to the heat energy utilization system, and the water outlet of the heat energy utilization system is connected to the hot water tank;

[0011] After the hot water in the hot water tank is heat exchanged through the conversion hot water cooler and the conversion refrigerant condenser, part of it flows back into the hot water tank and part of it enters the flash tank. After flash evaporation, the saturated water in the flash tank flows back to the hot water tank, and the steam in the flash tank enters the heat energy utilization system for heat exchange to generate condensed water, which then flows back into the hot water tank.

[0012] Furthermore, the water inlet of the conversion hot water cooler is connected to the public system, the water outlet of the conversion hot water cooler is connected to the polymerization system, and the shell side medium of the conversion hot water cooler is soft water sent to the polymerization system.

[0013] Furthermore, the shell side medium in the conversion refrigerant condenser is heptane.

[0014] Furthermore, the hot water tank is a pressure vessel.

[0015] Furthermore, the heat energy utilization system includes a primary brine system heat exchanger, a secondary brine system heat exchanger, a PVC resin dry hot water heat exchanger and a polymer softening water system heat exchanger, and the primary brine system heat exchanger, the secondary brine system heat exchanger, the PVC resin dry hot water heat exchanger and the polymer softening water system heat exchanger are respectively connected to the top of the flash tank; the primary brine system heat exchanger, the secondary brine system heat exchanger, the PVC resin dry hot water heat exchanger and the polymer softening water system heat exchanger, the water outlets of the primary brine system heat exchanger, the secondary brine system heat exchanger, the PVC resin dry hot water heat exchanger and the polymer softening water system heat exchanger are respectively connected to the inlet of the hot water tank.

[0016] Furthermore, the lower part of the hot water tank is connected to the conversion hot water cooler through a hot water pump.

[0017] Furthermore, the conversion hot water cooler is connected to the conversion refrigerant condenser via a hot water supply pipe.

[0018] Furthermore, the water outlet of the conversion refrigerant condenser is connected to the hot water tank and the flash tank through a hot water return main pipe, and a valve is provided on the branch pipe of the hot water return main pipe.

[0019] Furthermore, a nozzle is provided inside the flash tank.

[0020] Furthermore, the bottom of the flash tank is connected to the inlet of the hot water tank 3 through a saturated water pipeline 22 .

[0021] Furthermore, the top of the flash tank is connected to a heat energy utilization system through a steam pipe.

[0022] Furthermore, a remote pressure gauge and a steam pressure regulating valve are provided on the steam pipeline.

[0023] Furthermore, the water outlet of the heat energy utilization system is connected to the condensate collection tank 13, and the condensate collection tank is connected to the hot water tank through a steam condensate reflux pipe.

[0024] Furthermore, a condensate delivery pump is provided on the steam condensate return pipeline.

[0025] The utility model discloses a working process of a device for removing heat from PVC heptane and converting by-product steam by the calcium carbide process, comprising the following steps:

[0026] Step S1: The hot water in the hot water tank 3 enters the conversion hot water cooler for heat exchange;

[0027] Step S2: The hot water obtained through heat exchange in the previous step enters the conversion refrigerant condenser for heat exchange;

[0028] Step S3: a portion of the hot water from the heat exchange flows back into the hot water tank, and a portion enters the flash tank for flash evaporation;

[0029] Step S4: the saturated water in the flash tank flows back to the hot water tank, and the steam in the flash tank enters the heat energy utilization system for heat exchange to generate condensed water;

[0030] Step S5: The condensed water flows back into the hot water tank.

[0031] The utility model is suitable for recycling the waste heat of hot water converted by the heptane heat removal system under high-temperature reaction conditions without mercury catalysts. The heat utilization rate is higher than that of traditional lithium bromide heat exchange, which is of great significance for energy saving and consumption reduction in chlor-alkali enterprises. The cold medium of the hot water cooler is replaced by desalinated soft water for polymerization instead of circulating water, which firstly reduces the amount of circulating water and secondly utilizes the waste heat of hot water to heat the soft water for polymerization system, thereby reducing the amount of steam used for heating the soft water. In addition, the pure water medium is less corrosive, thereby avoiding the risk of heat exchanger leakage caused by poor circulating water quality.

[0032] The utility model configures the hot water tank as a pressure vessel, and the by-product steam is completely recovered in a closed manner, which reduces the escape of water vapor. It is not only environmentally friendly but also has a high energy utilization rate. The entire heat exchange system operates at a positive pressure to prevent oxygen from entering the system, thereby reducing the corrosion of equipment and pipelines caused by the increase in oxygen content in pure water.

[0033] The utility model produces steam by-product by arranging a flash tank on the hot water tank, which offsets the process scheme of arranging a steam drum for each single converter, and has the advantages of low equipment investment, small footprint, compact layout and simple transformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The utility model is a schematic structural diagram of a device for heat removal and conversion of heptane from calcium carbide-based PVC to produce by-product steam.

[0035] The reference numerals in the figures are as follows:

[0036] 1- utility system, 2- polymerization system, 3- hot water tank, 4- hot water pump, 5- conversion refrigerant condenser, 6- hot water return main, 7- valve, 8- conversion hot water cooler, 9- flash tank, 10- saturated steam pipeline, 11- steam condensate return pipeline, 12- condensate delivery pump, 13- condensate collection tank, 14- primary brine system heat exchange equipment, 15- secondary brine system heat exchange equipment, 16- PVC resin dry hot water heat exchange equipment, 17- polymerization soft water system heat exchange equipment, 19- nozzle, 20- hot water supply pipeline, 21- hot water pipeline, 22- saturated water, 23- steam pressure regulating valve, 24- remote pressure gauge. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the implementation of the utility model clearer, the technical solution in the implementation of the utility model will be clearly and completely described below in conjunction with the drawings in the implementation of the utility model. Obviously, the described implementation is a part of the implementation of the utility model, not all of the implementations. Based on the implementation of the utility model, all other implementations obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0038] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0040] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In order to better understand the purpose, structure and function of the utility model, the utility model is further described in detail below with reference to the accompanying drawings, in which a device for heat removal and conversion of heptane by-product steam of PVC by the calcium carbide process is described.

[0042] Embodiment 1:

[0043] like Figure 1 As shown, the utility model is a device for heat removal and conversion of by-product steam of PVC heptane by calcium carbide process, comprising a hot water tank 3, a conversion hot water cooler 8, a conversion refrigerant condenser 5, a flash tank 9 and a heat energy utilization system;

[0044] The water outlet of the hot water tank 3 is connected to the conversion hot water cooler 8, the water outlet of the conversion hot water cooler 8 is connected to the conversion refrigerant condenser 5, the water outlet of the conversion refrigerant condenser 5 is connected to the water inlets of the hot water tank 3 and the flash tank 9, the bottom of the flash tank 9 is connected to the water inlet of the hot water tank 3, the top of the flash tank 9 is connected to the heat energy utilization system, and the water outlet of the heat energy utilization system is connected to the hot water tank 3;

[0045] After the hot water in the hot water tank 3 is heat exchanged through the conversion hot water cooler 8 and the conversion refrigerant condenser 5, part of it flows back into the hot water tank 3, and part of it enters the flash tank 9. After flash evaporation, the saturated water in the flash tank 9 flows back to the hot water tank 3, and the steam in the flash tank 9 enters the heat energy utilization system for heat exchange to generate condensed water, which then flows back into the hot water tank 3.

[0046] Embodiment 2:

[0047] like Figure 1 As shown, the utility model is a device for heat removal and conversion of by-product steam of PVC heptane by calcium carbide process, comprising a hot water tank 3, a conversion hot water cooler 8, a conversion refrigerant condenser 5, a flash tank 9 and a heat energy utilization system;

[0048] The water outlet of the hot water tank 3 is connected to the conversion hot water cooler 8, the water outlet of the conversion hot water cooler 8 is connected to the conversion refrigerant condenser 5, the water outlet of the conversion refrigerant condenser 5 is connected to the water inlets of the hot water tank 3 and the flash tank 9, the bottom of the flash tank 9 is connected to the water inlet of the hot water tank 3, the top of the flash tank 9 is connected to the heat energy utilization system, and the water outlet of the heat energy utilization system is connected to the hot water tank 3;

[0049] After the hot water in the hot water tank 3 is heat exchanged through the conversion hot water cooler 8 and the conversion refrigerant condenser 5, part of it flows back into the hot water tank 3, and part of it enters the flash tank 9. After flash evaporation, the saturated water in the flash tank 9 flows back to the hot water tank 3, and the steam in the flash tank 9 enters the heat energy utilization system for heat exchange to generate condensed water, which then flows back into the hot water tank 3.

[0050] The difference between this embodiment and the first embodiment is that:

[0051] The water inlet of the conversion hot water cooler 8 is connected to the public system 1, and the water outlet of the conversion hot water cooler 8 is connected to the polymerization system 2. The shell-side medium of the conversion hot water cooler 8 is soft water sent to the polymerization system 2. Firstly, the amount of circulating water is reduced, and secondly, the waste heat of hot water is used to heat the soft water sent to the polymerization system 2, thereby reducing the amount of steam used to heat the soft water. On the other hand, the pure water medium is less corrosive, thereby avoiding the risk of heat exchanger leakage caused by poor circulating water quality.

[0052] The shell side medium in the conversion refrigerant condenser 5 is heptane.

[0053] The hot water tank 3 is a pressure vessel, and the by-product steam is completely recovered in a closed manner, which reduces the escape of water vapor. It is not only environmentally friendly but also has high energy utilization rate.

[0054] The heat energy utilization system includes a primary brine system heat exchange device 14, a secondary brine system heat exchange device 15, a PVC resin dry hot water heat exchange device 16 and a polymer soft water system heat exchange device 17. The primary brine system heat exchange device 14, the secondary brine system heat exchange device 15, the PVC resin dry hot water heat exchange device 16 and the polymer soft water system heat exchange device 17 are respectively connected to the top of the flash tank 9; the primary brine system heat exchange device 14, the secondary brine system heat exchange device 15, the PVC resin dry hot water heat exchange device 16 and the polymer soft water system heat exchange device 17, the water outlets of the primary brine system heat exchange device 14, the secondary brine system heat exchange device 15, the PVC resin dry hot water heat exchange device 16 and the polymer soft water system heat exchange device 17 are respectively connected to the inlet of the hot water tank 3.

[0055] The bottom of the hot water tank is connected to the conversion hot water cooler 8 through a hot water pump 4. The hot water pump 4 pumps the hot water in the hot water tank 3 into the conversion hot water cooler 8 for heat exchange.

[0056] The conversion hot water cooler 8 is connected to the conversion refrigerant condenser 5 through a hot water supply pipe 20, and the hot water enters the conversion refrigerant condenser 5 to exchange heat with heptane.

[0057] The water outlet of the conversion refrigerant condenser 5 is connected to the hot water tank 3 and the flash tank 9 through the hot water return main pipe 6, and a valve 7 is provided on the branch pipe of the hot water return main pipe 6.

[0058] A nozzle 19 is provided inside the flash tank 9 , and hot water enters the flash tank 9 through the nozzle 19 .

[0059] The bottom of the flash tank 9 is connected to the inlet of the hot water tank 3 through a saturated water pipeline 22 .

[0060] The top of the flash tank 9 is connected to the heat energy utilization system through a steam pipe 10;

[0061] The steam pipeline 10 is provided with a remote pressure gauge 24 and a steam pressure regulating valve 23 .

[0062] The water outlet of the heat energy utilization system is connected to the condensate collection tank 13 , and the condensate collection tank 13 is connected to the hot water tank 3 through a steam condensate return pipe 11 , and a condensate delivery pump 12 is provided on the steam condensate return pipe 11 .

[0063] The working process of the utility model is as follows:

[0064] Step S1: The hot water in the hot water tank 3 enters the conversion hot water cooler 8 for heat exchange;

[0065] Step S2: the hot water obtained through heat exchange in the previous step enters the conversion refrigerant condenser 5 for heat exchange;

[0066] Step S3: a portion of the hot water from the heat exchange flows back into the hot water tank 3, and a portion enters the flash tank 9 for flash evaporation;

[0067] Step S4: the saturated water in the flash tank 9 flows back to the hot water tank 3, and the steam in the flash tank 9 enters the heat energy utilization system for heat exchange to generate condensed water;

[0068] Step S5: the condensed water flows back into the hot water tank 3.

[0069] The above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. For those skilled in the art, the utility model may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model are included in the protection scope of the utility model.

Claims

1. A device for heat removal and conversion of by-product steam from heptane of PVC produced by the calcium carbide process, characterized in that: It includes a hot water tank, a conversion hot water cooler, a conversion refrigerant condenser, a flash tank and a heat energy utilization system; The water outlet of the hot water tank is connected to the conversion hot water cooler, the water outlet of the conversion hot water cooler is connected to the conversion refrigerant condenser, the water outlet of the conversion refrigerant condenser is connected to the water inlets of the hot water tank and the flash tank, the bottom of the flash tank is connected to the water inlet of the hot water tank, the top of the flash tank is connected to the heat energy utilization system, and the water outlet of the heat energy utilization system is connected to the hot water tank; After the hot water in the hot water tank is heat exchanged through the conversion hot water cooler and the conversion refrigerant condenser, part of it flows back into the hot water tank and part of it enters the flash tank. After flash evaporation, the saturated water in the flash tank flows back to the hot water tank, and the steam in the flash tank enters the heat energy utilization system for heat exchange to generate condensed water, which then flows back into the hot water tank.

2. The device for heat removal and conversion of by-product steam of PVC produced by the calcium carbide process according to claim 1, characterized in that: The water inlet of the conversion hot water cooler is connected to the public system, the water outlet of the conversion hot water cooler is connected to the polymerization system, and the shell side medium of the conversion hot water cooler is soft water sent to the polymerization system.

3. The device for heat removal and conversion of by-product steam of calcium carbide process PVC heptane according to claim 2 is characterized in that: The shell side medium in the conversion refrigerant condenser is heptane.

4. The device for heat removal and conversion of by-product steam of calcium carbide process PVC heptane according to claim 3 is characterized in that: The hot water tank is a pressure vessel.

5. The device for heat removal and conversion of by-product steam of calcium carbide process PVC heptane according to claim 4 is characterized in that: The heat energy utilization system includes a primary brine system heat exchanger, a secondary brine system heat exchanger, a PVC resin dry hot water heat exchanger and a polymer softening water system heat exchanger, and the primary brine system heat exchanger, the secondary brine system heat exchanger, the PVC resin dry hot water heat exchanger and the polymer softening water system heat exchanger are respectively connected to the top of the flash tank; the primary brine system heat exchanger, the secondary brine system heat exchanger, the PVC resin dry hot water heat exchanger and the polymer softening water system heat exchanger, and the water outlets of the primary brine system heat exchanger, the secondary brine system heat exchanger, the PVC resin dry hot water heat exchanger and the polymer softening water system heat exchanger are respectively connected to the inlet of the hot water tank.

6. The device for heat removal and conversion of by-product steam of PVC produced by the calcium carbide process according to claim 5, characterized in that: The bottom of the hot water tank is connected to the conversion hot water cooler through a hot water pump.

7. The device for heat removal and conversion of by-product steam from heptane of PVC produced by the calcium carbide process according to claim 6, characterized in that: The conversion hot water cooler is connected to the conversion refrigerant condenser through a hot water supply pipeline.

8. The device for heat removal and conversion of by-product steam of PVC produced by the calcium carbide process according to claim 7, characterized in that: The water outlet of the conversion refrigerant condenser is connected to the hot water tank and the flash tank through a hot water return main pipe, and a valve is arranged on the branch pipe of the hot water return main pipe.

9. The device for heat removal and conversion of by-product steam of PVC produced by the calcium carbide process according to claim 8, characterized in that: A nozzle is provided inside the flash tank.

10. The device for heat removal and conversion of by-product steam from heptane of PVC produced by the calcium carbide process according to claim 9, characterized in that: The lower part of the flash tank is connected to the inlet of the hot water tank through a saturated water pipeline; the upper part of the flash tank is connected to the heat energy utilization system through a steam pipeline.

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