Pressurizing device for hot water tower of process equipment for preparing chloroethylene by hydrochlorination of acetylene

Abstract

The present application relates to a kind of for the preparation of vinyl chloride by acetylene hydrochlorination process equipment hot water tower pressurizing device, including installation with pressurized combination valve hot water tower;The hot water tower includes hot water tank and heat exchanger;Steam pipe for passing through steam is arranged in the hot water tank;The hot water tank is connected with desalted water by pipeline;The hot water tank is connected with hot water circulating pump by pipeline;The hot water circulating pump is connected with converter by pipeline;The converter is connected with hot water tank by pipeline.The present application is by being arranged for steam venting pressure control adjustment pressurized combination valve, to carry out pressurization to the pressure in hot water tower and reach 1 atmospheric pressure, to let hot water temperature rise from 92 ℃ to 100 ℃, since the rise of hot water temperature promotes the reaction raw gas temperature of entering preheater to rise, to make it in converter catalytic action under the reaction conversion rate of improvement;Reached the purpose of production cost reduction, and the safety of production process is improved.

Description

Technical Field

[0001] This invention belongs to the field of chlor-alkali chemical technology, specifically relating to a pressurization device for a hot water tower in a process equipment for the hydrochlorination of acetylene to produce vinyl chloride. Background Technology

[0002] Vinyl chloride monomer is an important raw material for organic synthetic chemicals. Its synthesis is usually achieved through the hydrochlorination of acetylene. Therefore, the vast majority of polyvinyl chloride (PVC) raw materials are produced through this reaction. The catalyst used in this reaction is usually mercuric chloride, and the reaction takes place in a converter. During the reaction, the reaction gases need to be preheated through hot water pipes before entering the converter. That is, a preheater is used to preheat the mixed acetylene and hydrogen chloride gases. The preheating temperature is the initial temperature of the converter, which is determined by the hot water temperature. The higher the hot water temperature, the better the reaction effect of hydrogen chloride and acetylene under the catalysis of mercuric chloride catalyst. At the same time, this reaction is exothermic. The heat generated will be carried away by the vaporization of the hot water in the pipes between the converter. Since the liquid phase to gas phase conversion requires rapid heat absorption, the higher the temperature of the hot water in the pipes, the faster the vaporization occurs, and the better the heat removal effect.

[0003] However, the inventors discovered that, due to the high altitude of their facility, the production of vinyl chloride using the aforementioned process suffers from several problems. Firstly, the hot water temperature cannot reach 100°C, leading to incomplete reaction of the hydrogen chloride and acetylene mixture and resulting in low vinyl chloride conversion rates. Secondly, the catalyst in the converter has a short lifespan and high consumption. Thirdly, the high hydrogen chloride content in the exhaust gas leads to high consumption of the neutralizing agent liquid alkali required for purification and neutralization. Fourthly, the high acetylene content in the exhaust gas poses a safety hazard to subsequent processes. These combined factors result in high production costs. Therefore, this invention aims to solve these technical problems. Summary of the Invention

[0004] In accordance with the problems mentioned in the background art, the present invention provides a pressurization device for a hot water tower in a process equipment for the hydrochlorination of acetylene to produce vinyl chloride, comprising a hot water tower equipped with a pressurization combination valve; the hot water tower includes a hot water tank and a heat exchanger; a steam pipe for passing steam is provided in the hot water tank; the hot water tank is connected to demineralized water via a pipeline; the hot water tank is connected to a hot water circulation pump via a pipeline; the hot water circulation pump is connected to a converter via a pipeline; and the converter is connected to the hot water tank via a pipeline.

[0005] Furthermore, a booster-type combination valve is installed at the N5 interface where the hot water tower is located. The booster-type combination valve includes a parallel explosion-proof plate and a flow control valve FC. A check valve and a PG pressure gauge are installed at the N5 interface and on the pipeline where the combination valve is located. A shut-off valve is installed at the front end of the flow control valve FC and at the front end of the explosion-proof plate. The PG pressure gauge is communicatively connected to the flow control valve FC via a signal line.

[0006] Furthermore, a hot water supply pipeline HWS-H5 is connected to the N11 interface where the hot water tower is located. A heat exchanger, a hot water circulation pump L1, and a hot water circulation pump R2, as well as corresponding combination valves, are connected to the hot water supply pipeline HWS-H5. The hot water in the hot water tower is pressurized and pumped into the hot water supply pipeline HWS-H5 by the hot water circulation pump L1 or the hot water circulation pump R2, and flows to the converter.

[0007] Furthermore, a hot water return pipe HWR-H is connected to the N13 interface where the hot water tower is located. A heat exchanger and corresponding valve are connected to the hot water return pipe HWR-H. The hot water used by the converter returns to the hot water tower through the hot water return pipe HWR-H.

[0008] Furthermore, the water heated by the hot water tower is supplied by the demineralized water pipeline DNW-H.

[0009] Furthermore, the heat source used by the hot water tower is supplied by the low-pressure steam pipeline LS-H.

[0010] Furthermore, the steam used in the hot water tower is liquefied and then returned to distilled water via the hot water return pipeline HWR-H1.

[0011] Furthermore, the hot water tower also includes a hot water supply pipe HWS-H6 connected thereto.

[0012] Beneficial effects: This invention uses a pressure-boosting combination valve installed at the vent pipe end of the hot water tower for steam vent pressure control and regulation. This boosts the pressure inside the hot water tower and controls it to reach 1 atmosphere, raising the hot water temperature from 92℃ to 100℃. The increased hot water temperature causes the temperature of the reactant gas entering the preheater to rise. The higher temperature reacts more significantly in the converter under the action of the catalyst, improving the conversion rate. Furthermore, the content of acetylene and hydrogen chloride discharged from the converter decreases, leading to reduced consumption of liquid alkali and catalyst in subsequent processes, thus optimizing the equipment and reducing production costs. Simultaneously, the reduced acetylene content in the vinyl chloride gas after the reaction enhances the safety of the process. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a structural block diagram of the booster device proposed in this invention;

[0015] Figure 2 This is a schematic diagram of the equipment process layout of the booster device proposed in this invention. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] The inventor's institution is located in Qinghai Province, a region characterized by high altitude, ranging from approximately 2280 to 3200 meters, with an atmospheric pressure of 77 kPa. The boiling point of water is around 92°C, and further heating to 100°C results in vaporization. However, this heating process suffers from poor vaporization despite continuous boiling. In the acetylene hydrochlorination process for producing vinyl chloride, this hot water, heated in a hot water tower, serves as the heat source for the converter, promoting the catalytic reaction of mercuric chloride. Simultaneously, the heat of reaction released during the reaction of acetylene and hydrogen chloride needs to be rapidly removed. Because the hot water supplied by the tower is relatively low, failing to reach the liquid-to-gas phase transition temperature, the latent heat of reaction is poorly removed, impacting vinyl chloride production and negatively affecting subsequent processes.

[0018] Example 1: Please refer to the appendix Figure 1As shown, this invention further improves the structure of the hot water tower and provides a pressurization device for the hot water tower in the acetylene hydrochlorination process to produce vinyl chloride. The device includes a hot water tower equipped with a pressurization combination valve. The hot water tower includes a hot water tank and a heat exchanger. A steam pipe is installed in the hot water tank. Steam heats the hot water in the tank through the steam pipe, and then liquefies it into distilled water through the heat exchanger. Simultaneously, the heat released during the gas-to-liquid phase conversion provides heat to the hot water tank. The pressure value of the pressurization combination valve is set to one standard atmosphere to compensate for situations where the pressure inside the hot water tower is lower than the standard atmosphere. When the pressure inside the hot water tower is higher than the standard atmosphere, the system vents. The hot water tank is connected to demineralized water via a pipeline to replenish demineralized water when the hot water tank is short of water. The hot water tank is connected to a hot water circulation pump via a pipeline. The heated hot water is pumped into a converter, where the latent heat of the acetylene hydrochlorination reaction is carried away through the liquid-to-gas phase conversion principle, and then flows back to the hot water tank.

[0019] The aforementioned pressurization device can increase the atmospheric pressure inside the hot water tower from 77 kPa to standard atmospheric pressure, so that the hot water can be heated to the critical value of 100°C. This hot water is pumped into the converter by the hot water circulation pump. Due to the release of latent heat from the acetylene hydrochlorination reaction, the hot water is converted into steam. This provides the converter with the optimal temperature required for a stable chemical reaction and also quickly removes the latent heat of reaction.

[0020] Example 2: Please refer to the appendix Figure 2 As shown, the booster combination valve is installed at the N5 interface where the hot water tower is located. The booster combination valve includes a parallel explosion-proof plate and a flow control valve FC. A check valve and a PG pressure gauge are installed at the N5 interface and on the pipeline where the combination valve is located. A shut-off valve is installed at the front end of the flow control valve FC and at the front end of the explosion-proof plate. The PG pressure gauge controls the opening of the flow control valve FC through a signal line. When the pressure in the venting pipeline exceeds the control value, that is, exceeds the threshold set by the PG pressure gauge, the flow control valve FC is opened to release pressure. If the pressure in the venting pipeline exceeds the limit value, the explosion-proof plate ruptures to release pressure, which is used to prevent damage to the pipeline or equipment. The shut-off valve is used during the maintenance of the venting pipeline, and the check valve prevents the backflow of gas in the venting pipeline.

[0021] By using a pipeline system with a self-controlled loop formed by a PG pressure gauge and a FC flow control valve, the steam pressure inside the hot water tower can be further increased by 24 kPa, reaching the standard atmospheric pressure of 101 kPa. Consequently, the hot water temperature can be raised to the critical value of 100°C, thus solving the problem of low atmospheric pressure and low vaporization temperature of hot water at high altitudes.

[0022] Specifically, the pressurization device for the hot water tower in the acetylene hydrochlorination process to produce vinyl chloride also includes the following structure:

[0023] The hot water tower is connected to a hot water supply pipeline HWS-H5 at the N11 interface. A heat exchanger, hot water circulation pump L1, and hot water circulation pump R2, along with corresponding combination valves, are connected to the HWS-H5 pipeline. Hot water from the hot water tower is pressurized and pumped into the HWS-H5 pipeline by either hot water circulation pump L1 or R2, and then flows to the converter. Hot water circulation pump L1 or R2 serves as the primary and backup pumps to improve equipment operating efficiency.

[0024] The hot water tower is connected to the N13 interface via a hot water return pipe HWR-H, which is connected to a heat exchanger and corresponding valves. The hot water used by the converter returns to the hot water tower via the hot water return pipe HWR-H.

[0025] The water heated by the hot water tower is supplied by the demineralized water pipeline DNW-H.

[0026] The heat source used by the hot water tower is supplied by the low-pressure steam pipeline LS-H.

[0027] The steam used in the hot water tower is liquefied and then returned to the distillation return water via the hot water return pipeline HWR-H1; the by-product distillation return water increases the added value of production.

[0028] The hot water in the hot water tower also supplies heat to other related equipment through the hot water supply pipeline HWS-H6 connected to it.

[0029] Through the implementation of this invention, the pressure inside the hot water tower is increased by adding a pressure-boosting combination valve, thereby increasing the steam pressure of the hot water by 24 kPa, compensating the hot water tower to the standard atmospheric pressure of 101 kPa. As the pressure of the hot water tower increases, the corresponding hot water temperature rises to 100°C, thus increasing the hot water temperature. With the hot water in the preheater of the reaction gas before entering the converter being heated, the gas reaction in the converter is enhanced. Simultaneously, the temperature of the hot water used to remove the latent heat of reaction in the converter is correspondingly increased, further enhancing the reaction in the conversion reactor. This results in improved conversion reaction efficiency, reduced catalyst usage, and decreased usage of liquid alkali (a neutralizing agent for incompletely reacted hydrogen chloride in the purified gas), leading to a reduction in equipment production costs and ultimately lower production costs.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pressurization device for a hot water tower in a process equipment for the hydrochlorination of acetylene to produce vinyl chloride, characterized in that, The system includes a hot water tower equipped with a booster valve; the hot water tower includes a hot water tank and a heat exchanger; the hot water tank is equipped with a steam pipe for steam passage; the hot water tank is connected to demineralized water via a pipeline; the hot water tank is connected to a hot water circulation pump via a pipeline; the hot water circulation pump is connected to a converter via a pipeline; and the converter is connected to the hot water tank via a pipeline.

2. The pressurization device for a hot water tower in a process equipment for the hydrochlorination of acetylene to produce vinyl chloride, as described in claim 1, is characterized in that, The booster valve is installed at the N5 interface where the hot water tower is located. The booster valve includes a parallel explosion-proof plate and a flow control valve FC. A check valve and a PG pressure gauge are installed at the N5 interface and on the pipeline where the valve is located. A shut-off valve is installed at the front end of the flow control valve FC and at the front end of the explosion-proof plate. The PG pressure gauge is communicatively connected to the flow control valve FC via a signal line.

3. The pressurization device for a hot water tower in a process equipment for the hydrochlorination of acetylene to produce vinyl chloride, as described in claim 2, is characterized in that... The hot water tower is connected to the N11 interface via a hot water supply pipeline HWS-H5. A heat exchanger, a hot water circulation pump L (1), and a hot water circulation pump R (2) are connected to the hot water supply pipeline HWS-H5, along with corresponding combination valves. The hot water in the hot water tower is pressurized and pumped into the hot water supply pipeline HWS-H5 by the hot water circulation pump L (1) or the hot water circulation pump R (2), and flows to the converter.

4. The pressurization device for a hot water tower in a process equipment for the hydrochlorination of acetylene to produce vinyl chloride, as described in claim 2, is characterized in that... The hot water tower is connected to the N13 interface via a hot water return pipe HWR-H, which is connected to a heat exchanger and corresponding valves. The hot water used by the converter returns to the hot water tower via the hot water return pipe HWR-H.

5. A pressurization device for a hot water tower in a process equipment for the hydrochlorination of acetylene to produce vinyl chloride, as described in claim 2, is characterized in that, The water heated by the hot water tower is supplied by the demineralized water pipeline DNW-H.

6. A pressurization device for a hot water tower in a process equipment for the hydrochlorination of acetylene to produce vinyl chloride, as described in claim 2, is characterized in that... The heat source used by the hot water tower is supplied by the low-pressure steam pipeline LS-H.

7. A pressurization device for a hot water tower in a process equipment for the hydrochlorination of acetylene to produce vinyl chloride, as described in claim 2, is characterized in that... The steam used in the hot water tower is liquefied and then returned to the hot water return pipe HWR-H1 as distilled return water.

8. A pressurization device for a hot water tower in a process equipment for the hydrochlorination of acetylene to produce vinyl chloride, as described in any one of claims 1-7, characterized in that, The hot water tower also includes a hot water supply pipeline HWS-H6 connected to it.

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