A liquid chlorine gasification process

Abstract

The present application is suitable for chlorine production technical field, provide a kind of liquid chlorine gasification process, comprising the following steps: step one: liquid chlorine steel bottle in liquid chlorine bottle storehouse is connected into distillation column for distillation separation by liquid chlorine distribution platform;Step two: gaseous material from the top of distillation column enters condenser, and the liquid outlet of condenser is connected with chlorine gasifier by liquid chlorine pipeline;Step three: liquid chlorine enters the inner tube of chlorine gasifier, and is heated by 80-83 DEG C medium, and liquid chlorine is gasified by heat absorption;Step four: after drying and impurity removal, chlorine is sent to chlorine buffer tank by chlorine turbine compressor, and after the stable pressure of chlorine in chlorine buffer tank, it is sent to each chlorine point by chlorine pipe network.The distillation column and chlorine dryer can remove nitrogen trichloride, metal chloride and non-metallic chloride, thereby improving the purity of chlorine, and avoiding the influence on bromine extraction;The establishment of accident chlorine absorption device can handle leaked chlorine in time, and guarantee the safety of chlorine use.

Description

Technical Field

[0001] This invention relates to the field of chlorine production technology and provides a liquid chlorine vaporization process. Background Technology

[0002] Chlorine is a yellowish-green, highly toxic gas with a strong, pungent odor. It is asphyxiating and denser than air. It is soluble in water and alkaline solutions, readily soluble in organic solvents, and sparingly soluble in saturated saline solution. It is easily compressed and can be liquefied into a yellowish-green, oily liquid chlorine.

[0003] Chlorine is one of the main products of the chlor-alkali industry. It can undergo substitution or addition reactions with organic and inorganic substances to produce various chlorides and can also be used as a strong oxidizing agent. Bromine, as an important chemical raw material, has wide applications in various fields of industrial production, scientific research, and daily life. In the preparation of bromine, bromine can be extracted by oxidizing bromides with chlorine. This process requires a large amount of chlorine. If the chlorine is impure, it will not only affect the efficiency of bromide oxidation but also result in impurities in the extracted bromine, affecting its purity and quality. Therefore, improving the purity of chlorine plays a crucial role in the production of high-quality bromine. Summary of the Invention

[0004] In view of the deficiencies pointed out in the background art, the object of the present invention is to provide a liquid chlorination process that can obtain high-purity chlorine gas.

[0005] To achieve the above objectives, the present invention provides a liquid chlorine vaporization process, comprising the following steps:

[0006] Step 1: Set up a liquid chlorine cylinder storage area. Each liquid chlorine cylinder is connected in parallel through a liquid chlorine distribution station. The inlet of the liquid chlorine distribution station is equipped with a filter. The filter is connected to the liquid chlorine loading arm through the inlet pipeline. The inlet pipeline is equipped with a liquid chlorine shut-off valve, which is interlocked with the liquid chlorine distribution station. The outlet of the liquid chlorine distribution station is connected to the bottom of the distillation tower through the outlet pipeline. The outlet pipeline is equipped with a flow regulating valve. Both the inlet and outlet pipelines are wrapped with flexible foam rubber and plastic sheets with an oxygen index greater than 38%.

[0007] Step 2: The pressure in the distillation column is reduced by a vacuum pump. The liquid chlorine in the distillation column is heated and evaporated. The bottom liquid of the distillation column is sent to the treatment tank. An alkaline substance is added to the treatment tank for neutralization or an oxidant is added for oxidation. The gaseous substance coming out from the top of the distillation column enters the condenser. The liquid outlet of the condenser is connected to the chlorine vaporizer through a liquid chlorine pipeline. The liquid chlorine pipeline is wrapped with flexible foam rubber and plastic sheet with an oxygen index greater than 38%. The drain outlet of the condenser is connected to the absorption tank through a pipeline for absorption reaction.

[0008] Step 3: Connect the chlorine vaporizer to the circulation pipeline of the heater. The medium heated by the heater is delivered to the outer pipe of the chlorine vaporizer by a liquid pump. Liquid chlorine enters the inner pipe of the chlorine vaporizer and is heated by a medium at 80-83℃. The liquid chlorine absorbs heat and vaporizes. A water temperature thermometer is installed at the heat medium inlet of the chlorine vaporizer. The water temperature thermometer is interlocked with the heater. The chlorine outlet of the chlorine vaporizer is connected to a chlorine dryer through a pipeline. The chlorine dryer is filled with adsorbent. A chlorine thermometer is installed at the chlorine outlet of the chlorine vaporizer. The chlorine thermometer alarms when the temperature drops below 70℃. The chlorine thermometer is interlocked with the liquid chlorine distribution table and the heater.

[0009] Step 4: After drying and impurity removal, the chlorine gas is pressurized by a chlorine turbine compressor and then delivered to a chlorine buffer tank. After the pressure in the chlorine buffer tank is stabilized, the chlorine gas is delivered to each chlorine point through the chlorine pipeline network. A pressure sensor is installed at the outlet of the chlorine buffer tank, and the pressure sensor is interlocked with the chlorine turbine compressor.

[0010] Preferably, the liquid chlorine cylinder storage is equipped with an emergency chlorine absorption device, which consists of a fan and an absorption tower. The liquid chlorine cylinder is placed in a spill-proof collection ditch. A chlorine leak alarm is installed on one side of the spill-proof collection ditch and is interlocked with the fan. A suction hood is installed above the spill-proof collection ditch. The fan collects the leaked chlorine gas through the suction hood and draws it into the absorption tower. The chlorine gas enters the tower from the bottom and is absorbed in the packing layer in a countercurrent contact with the absorbent liquid sprayed down from the top of the tower.

[0011] Preferably, the lower limit of the alarm interlock value of the chlorine leak alarm is 0.4 ppm.

[0012] Preferably, the chlorine vaporizer is equipped with a pressure relief device connected to the absorption tower. When the internal pressure of the chlorine vaporizer exceeds the threshold, the pressure relief device is activated, and chlorine is drawn along the pipeline to the absorption tower for absorption reaction.

[0013] Preferably, the absorbent liquid at the bottom of the absorption tower is pumped into the first cooler by the first circulating pump to exchange heat with the circulating cold water. The absorbent liquid with a lower temperature coming out of the first cooler re-enters the absorption tower. The material outlet pipeline of the first cooler is equipped with a first thermometer, which is interlocked with the first cooler to ensure that the temperature of the absorbent liquid does not exceed 45°C.

[0014] Preferably, the exhaust gas from the top of the absorption tower is pumped to the exhaust gas tower, where it undergoes an absorption reaction in the packing layer with the absorbent liquid that is sprayed down from the top of the tower in a countercurrent flow. The exhaust gas that meets the environmental emission standards is discharged from the top of the tower and released into the atmosphere by a fan.

[0015] Preferably, the absorbent liquid at the bottom of the tail gas tower is pumped into the second cooler by the second circulation pump to exchange heat with the circulating cold water. The absorbent liquid with a lower temperature coming out of the second cooler re-enters the tail gas tower. A second thermometer is installed on the material outlet pipeline of the tail gas tower. The second thermometer is interlocked with the second cooler to ensure that the temperature of the absorbent liquid does not exceed 45°C.

[0016] Preferably, the chlorine buffer tank is regularly drained, and a drain pipe is provided at the bottom of the chlorine buffer tank, which leads to the liquid alkali tank. The distance between the outlet of the drain pipe and the liquid surface of the liquid alkali tank shall not be less than 50cm.

[0017] Preferably, the packing adsorbent of the chlorine dryer is activated copper oxide or activated carbon.

[0018] Preferably, the heater is heated by electric heating wire, PTC ceramic heating, or natural gas heating.

[0019] After adopting the above technical solution, the beneficial effects of the present invention are:

[0020] Distillation towers and chlorine dryers can remove nitrogen trichloride, metal chlorides and non-metal chlorides, thereby improving the purity of chlorine and avoiding the impact on bromine extraction; the establishment of emergency chlorine absorption devices can promptly handle leaked chlorine and ensure the safety of chlorine use. Attached Figure Description

[0021] 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.

[0022] Figure 1 This is a process flow diagram for the vaporization of liquid chlorine. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Those skilled in the art will recognize that the invention can be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the invention by illustrating examples of it.

[0024] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of the present invention. It should also be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly, for example, referring to a fixed connection, a detachable connection, or an integral connection; it can refer to a direct connection or an indirect connection. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] This invention provides a liquid chlorine vaporization process, comprising the following steps:

[0026] Step 1: Set up a liquid chlorine cylinder storage facility. The liquid chlorine cylinder storage facility is equipped with an emergency chlorine absorption device. Each liquid chlorine cylinder is connected in parallel through a liquid chlorine distribution platform. The inlet of the liquid chlorine distribution platform is equipped with a filter. The filter is connected to the liquid chlorine loading arm through the inlet pipeline. The inlet pipeline is equipped with a liquid chlorine shut-off valve, which is interlocked with the liquid chlorine distribution platform. The outlet of the liquid chlorine distribution platform is connected to the bottom of the distillation tower through the outlet pipeline. The outlet pipeline is equipped with a flow regulating valve. Both the inlet and outlet pipelines are insulated.

[0027] Step 2: The pressure inside the system is reduced by a vacuum pump in the distillation column. By controlling the temperature and pressure, chlorine is distilled and separated. Chlorine and other impurities are separated in order of boiling point from high to low. The liquid chlorine in the distillation column is heated and evaporated. The gaseous substance coming out of the top of the distillation column enters the washing column, where hydrogen chloride gas is removed with alkaline solution. The chlorine gas coming out of the washing column enters the condenser. By utilizing the different condensation temperatures of different substances during the condensation process, impurities are separated. The liquid outlet of the condenser is connected to the chlorine vaporizer through a liquid chlorine pipeline. The liquid chlorine pipeline is insulated. The drain outlet of the condenser is connected to the absorption tank through a pipeline for absorption reaction.

[0028] Step 3: Connect the chlorine vaporizer to the heater's circulation pipeline. The medium heated by the heater is pumped to the outer pipe of the chlorine vaporizer. Liquid chlorine enters the inner pipe of the chlorine vaporizer and is heated by a medium at 80-83℃. The liquid chlorine absorbs heat and vaporizes. A water temperature thermometer is installed at the heat medium inlet of the chlorine vaporizer. The water temperature thermometer is interlocked with the heater. The chlorine outlet of the chlorine vaporizer is connected to a chlorine dryer through a pipeline. The chlorine dryer is filled with an adsorbent. The adsorbent is activated copper oxide or activated carbon, which easily absorbs hydrogen chloride gas. A chlorine thermometer is installed at the chlorine outlet of the chlorine vaporizer. The chlorine thermometer alarms when the temperature drops below 70℃. The chlorine thermometer is interlocked with the liquid chlorine distribution station and the heater.

[0029] Step 4: After drying and impurity removal, the chlorine gas is pressurized by a chlorine turbine compressor and then delivered to a chlorine buffer tank. After the pressure in the chlorine buffer tank is stabilized, the chlorine gas is delivered to each chlorine point through the chlorine pipeline network. A pressure sensor is installed at the outlet of the chlorine buffer tank, and the pressure sensor is interlocked with the chlorine turbine compressor.

[0030] In steps one and two, the insulation measure involves wrapping the delivery pipeline with flexible foam rubber-plastic sheets with an oxygen index greater than 38% to prevent the accumulation of hydrated chlorine and subsequent blockage. The chlorine buffer tank is periodically drained. A drain pipe is located at the bottom of the chlorine buffer tank, through which impurities, including nitrogen trichloride, are led to the liquid alkali tank. The distance between the drain pipe opening and the liquid surface of the liquid alkali tank must not be less than 50 cm. The heater uses hot water as the heating medium, which is maintained by steam heating, electric heating wire heating, PTC ceramic heating, or natural gas heating. The hot water is delivered via a liquid pump for heat exchange with liquid chlorine. This process can be stabilized by adjusting the liquid chlorine flow rate or water temperature to maintain the pressure and temperature of the chlorine vaporizer.

[0031] The bottom liquid from the distillation and washing towers enters the first treatment tank, while the bottom liquid from the absorption and tail gas towers enters the second treatment tank for further processing. If the chlorine concentration in the bottom liquid is high, it can be recovered and reused. If the chlorine concentration is low, neutralization, adsorption, or oxidation methods can be used. During neutralization, the bottom liquid is mixed with an alkaline substance (such as sodium hydroxide or lime) to generate sodium chloride and other salts, thus removing chlorine from the bottom liquid. During adsorption, activated carbon or molecular sieves can be used to adsorb chlorine, achieving the purpose of removing chlorine from the bottom liquid. During oxidation, the bottom liquid is mixed with an oxidant, such as hydrogen peroxide or oxygen (under high temperature conditions), converting it into hypochlorite or higher-valence chlorides.

[0032] The emergency chlorine absorption unit consists of a fan and an absorption tower. Liquid chlorine cylinders are placed in a spill-proof collection ditch, protected from direct sunlight and high temperatures to prevent chlorine evaporation from causing a pressure buildup and potential explosion. A chlorine leak alarm is installed on one side of the collection ditch, interlocked with the fan. A suction hood is installed above the collection ditch. The alarm interlock threshold for the chlorine leak alarm is 0.4 ppm (400 milligrams per cubic meter), meaning it will be triggered when the leak is equal to or greater than 0.4 ppm. When a liquid chlorine cylinder leaks, the leaked chlorine vaporizes rapidly upon reaching the ground. Because chlorine is denser than air, it diffuses upwards from the ground; therefore, the chlorine leak alarm is positioned at a low location.

[0033] A blower collects leaking chlorine gas through a suction hood and draws it into the absorption tower. The chlorine gas enters the tower from the bottom and reacts counter-currently with the absorbent liquid sprayed from the top of the tower in the packing layer. A chlorine vaporizer is equipped with a pressure relief device connected to the absorption tower. When the internal pressure of the vaporizer exceeds a threshold, the pressure relief device opens, and the chlorine gas is drawn along the pipeline into the absorption tower for absorption. The heat generated by the absorption reaction raises the temperature of the absorbent liquid, slowing down the absorption rate; therefore, cooling is necessary. The absorbent liquid at the bottom of the absorption tower is pumped into a first cooler by a first circulating pump to exchange heat with circulating cold water. The cooler absorbent liquid exiting the first cooler re-enters the absorption tower. A first thermometer is installed on the material outlet pipeline of the first cooler, and the first thermometer is interlocked with the first cooler to ensure that the absorbent liquid temperature is maintained at 40-45℃.

[0034] The exhaust gas from the top of the absorption tower is drawn into the tail gas tower, where it undergoes a counter-current absorption reaction with the absorbent liquid sprayed down from the top of the tower in the packing layer. The exhaust gas, meeting environmental emission standards, is discharged through the top of the tower and released into the atmosphere by a fan. During this process, the heat generated by the reaction raises the temperature of the absorbent liquid, slowing down the absorption rate; therefore, cooling is necessary. The absorbent liquid at the bottom of the tail gas tower is pumped into a second cooler by a second circulation pump to exchange heat with circulating cold water. The cooler absorbent liquid exiting the second cooler re-enters the tail gas tower. A second thermometer is installed on the material outlet pipeline of the tail gas tower, interlocked with the second cooler to ensure the absorbent liquid temperature is maintained at 40-45℃.

[0035] The embodiments described above are not exhaustive and do not limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the above description. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to effectively utilize the invention and its modifications. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A liquid chlorine gasification process characterized by, It comprises the following steps: Step one: set up liquid chlorine cylinder library, each liquid chlorine cylinder is connected through liquid chlorine distribution table, the feed inlet of liquid chlorine distribution table is provided with filter, the filter is connected with liquid chlorine crane through feed pipeline, the feed pipeline is provided with liquid chlorine cut-off valve, the liquid chlorine cut-off valve is interlocked with liquid chlorine distribution table, the discharge outlet of liquid chlorine distribution table is connected with the bottom of distillation tower through discharge pipeline, the discharge pipeline is provided with flow regulating valve, the feed pipeline and discharge pipeline are wrapped with flexible foam rubber board with oxygen index greater than 38%; Step two: the pressure in the system is reduced by vacuum pump, the liquid chlorine in the distillation tower is heated and evaporated, the bottom liquid of the distillation tower is sent to the treatment tank, the alkaline substance is added into the treatment tank for neutralization treatment or the oxidizing agent is added for oxidation treatment, the gaseous material from the top of the distillation tower enters the condenser, the liquid outlet of the condenser is connected with chlorine gasifier through liquid chlorine pipeline, the liquid chlorine pipeline is wrapped with flexible foam rubber board with oxygen index greater than 38%, the exhaust port of the condenser is connected with the absorption tank through pipeline for absorption reaction; Step three: the chlorine gasifier is connected with the circulating pipeline of the heater, the medium heated by the heater is delivered to the outer pipe of the chlorine gasifier through the liquid pump, the liquid chlorine enters the inner pipe of the chlorine gasifier, is heated by the medium at 80-83 DEG C, and is gasified by absorbing heat, the heat medium inlet of the chlorine gasifier is provided with water temperature thermometer, the water temperature thermometer is interlocked with the heater, the chlorine gas outlet of the chlorine gasifier is connected with the chlorine gas dryer through pipeline, the chlorine gas dryer is filled with adsorbent, the chlorine gas outlet of the chlorine gasifier is provided with chlorine gas thermometer, the chlorine gas thermometer is lower than 70 DEG C, and an alarm is given, and the chlorine gas thermometer is interlocked with the liquid chlorine distribution table and the heater; Step four: the chlorine gas after drying and impurity removal is pressurized by the chlorine gas turbine compressor and delivered to the chlorine gas buffer tank, the chlorine gas is sent to each chlorine using point through the chlorine pipeline network after the pressure in the chlorine gas buffer tank is stabilized, the outlet of the chlorine gas buffer tank is provided with pressure sensor, and the pressure sensor is interlocked with the chlorine gas turbine compressor.

2. The liquid chlorine vaporization process of claim 1, wherein: The liquid chlorine cylinder library is provided with accident chlorine absorption device, the accident chlorine absorption device is composed of fan and absorption tower, the liquid chlorine cylinder is placed in the anti-flowing collection ditch, the chlorine leakage alarm instrument is installed on one side of the anti-flowing collection ditch, the chlorine leakage alarm instrument is interlocked with the fan, the upper portion of the anti-flowing collection ditch is provided with air suction hood, the fan collects the leaked chlorine through the air suction hood and sucks it into the absorption tower, and the chlorine enters the tower body from the bottom of the absorption tower, and is absorbed by countercurrent contact with the absorption liquid sprayed from the top of the tower and the packing layer.

3. The liquid chlorine vaporization process of claim 2, wherein: The lower limit of the alarm interlocking value of the chlorine leakage alarm instrument is 0.4ppm.

4. The liquid chlorine vaporization process of claim 2, wherein: The chlorine gasifier is provided with pressure relief device connected with the absorption tower, when the internal pressure of the chlorine gasifier exceeds the threshold value, the pressure relief device is opened, and the chlorine is sucked into the absorption tower along the pipeline for absorption reaction.

5. The liquid chlorine vaporization process of claim 2 or 4, wherein: The absorption liquid at the bottom of the absorption tower is pumped into the first cooler by the first circulating pump to exchange heat with circulating cold water, the absorption liquid with lower temperature from the first cooler reenters the absorption tower, the material outlet pipeline of the first cooler is provided with first thermometer, the first thermometer is interlocked with the first cooler, and the temperature of the absorption liquid is ensured to be not higher than 45 DEG C.

6. The liquid chlorine vaporization process of claim 5, wherein: The tail gas absorbed tower top is pumped to the tail gas tower, and the tail gas is contacted with the absorption liquid sprayed from the top of the tower in countercurrent to carry out absorption reaction, and the tail gas meeting the environmental protection emission standard is led out from the top of the tower and discharged into the atmosphere through the fan.

7. The liquid chlorine vaporization process of claim 6, wherein: The absorption liquid at the bottom of the tail gas tower is pumped into the second cooler through the second circulating pump to exchange heat with the circulating cold water, the absorption liquid with lower temperature from the second cooler reenters the tail gas tower, a second thermometer is arranged on the material outlet pipeline of the tail gas tower, and the second thermometer is interlocked with the second cooler to ensure that the temperature of the absorption liquid is not greater than 45 DEG C.

8. The liquid chlorine vaporization process of claim 1, wherein: The chlorine buffer tank is regularly discharged, a blowdown pipeline is arranged at the bottom of the chlorine buffer tank, the blowdown pipeline is led to the liquid alkali pool, and the distance from the blowdown pipeline to the liquid level of the liquid alkali pool is not less than 50 cm.

9. The liquid chlorine vaporization process of claim 1, wherein: The packing adsorbent of the chlorine gas dryer is active copper oxide or active carbon.

10. The liquid chlorine vaporization process of claim 1, wherein: The heating mode of the heater is electric heating wire heating, PTC ceramic heating or natural gas heating.

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