A liquid chlorine cylinder automatic filling device and method

Abstract

The present invention discloses an automatic filling device for a liquid chlorine steel cylinder, which is characterized by comprising a filling system (1), a control system (2), an exhaust gas evacuation system (3) and a pressure relief system (4). The present invention also discloses an automatic filling method for a liquid chlorine steel cylinder using the automatic filling device for a liquid chlorine steel cylinder. Compared with the prior art, the advantages of the present invention are that the automatic filling device and method for a liquid chlorine steel cylinder can automatically fill a liquid chlorine steel cylinder, and the liquid chlorine after filling has good quality, is safe and convenient.

Description

Technical Field

[0001] The invention relates to the technical field of liquid chlorine filling, and in particular to an automatic filling device and method for a liquid chlorine cylinder. Background Art

[0002] Chlorine is an important basic chemical raw material. There are thousands of chlorine derivatives, which are widely used in petrochemical, pesticide, medicine, textile, light industry, electric power, metallurgy, national defense and military industry, chemical building materials and other industries, and play a pivotal role in the development of the national economy. In addition, chlorine is also the main raw material for drinking water treatment, environmental disinfection and daily chemicals in people's daily life, which is closely related to people's lives.

[0003] Chlorine is a yellow-green, highly toxic gas with a strong pungent odor at room temperature and pressure. It is suffocating. The maximum allowable concentration in workshop air is 1 mg / m 3 The maximum allowable concentration in the atmosphere of residential areas is 0.1 mg / m 3 When the chlorine content in 1 liter of air exceeds 0.25 mg, a person staying in it for 30 minutes can die. In industry, chlorine is purified and frozen to liquefy into liquid chlorine, which is convenient for storage, packaging, transportation and use. Liquid chlorine is a transparent liquid with physical and chemical properties such as highly toxic, volatile, strong oxidant, combustion aid, and easy to explode when mixed with other flammable gases. It can be vaporized into gas under normal pressure, is very active, and can react with most substances. In order to meet the long-distance safe transportation of liquid chlorine, liquid chlorine production enterprises generally use cylinders and tank trucks for transportation.

[0004] The state stipulates that the filling coefficient of liquid chlorine shall not be greater than 1.25. In the current filling system of the factory, most of them are manually operated, which requires a high level of proficiency of the operators, and manual operation often leads to overfilling. Once the liquid chlorine cylinder is overfilled, it will be very dangerous during transportation. At the same time, the liquid chlorine filling process has certain dangers. Avoiding leakage, reducing labor intensity, reducing operating errors, and improving the degree of automation are the directions that the current liquid chlorine filling system urgently needs to improve.

[0005] In order to improve the safety of liquid chlorine filling, the invention patent "Liquid Chlorine Filling Device" with patent application number CN200910223934.0 (publication number CN101701664A) discloses a liquid chlorine filling device, including a liquid chlorine storage tank, a steel cylinder, and a safety alarm protection device. When filling, the safety valve and the feed valve are opened to start filling the steel cylinder with liquid chlorine. After the filling is completed, the safety valve, the feed valve and the steel cylinder mouth are closed, the drain valve is opened, the remaining chlorine in the pipeline is emptied, and the steel cylinder is unloaded. The advantage of this device is that the safety alarm protection device improves the safety of liquid chlorine filling, but the degree of automation is low, the manual operation is cumbersome, and the actual operation may often cause human errors to cause the safety valve to trip, which brings unnecessary trouble to the recovery system. The utility model patent "A Liquid Chlorine Automatic Filling System" with patent application number CN201120079883.1 (publication number CN202024078U) discloses a liquid chlorine automatic filling system, which uses an automatic control shut-off valve to automatically cut off the liquid chlorine after filling. The system has a simple structure and is easy to operate. It can effectively reduce the tediousness of manual operation and reduce the probability of safety accidents. However, the system has the following disadvantages: First, the shut-off valve only has full opening and full closing. On the one hand, the emergency opening and emergency stopping may cause the shut-off valve to be gradually damaged, and the valve needs to be replaced frequently, which is not conducive to the long-term stable operation of the system. At the same time, there may always be a system error of overfilling due to the untimely closing of the shut-off valve; second, the system is too dependent on the automatic control system and does not have safety measures when the automatic control system fails; third, there is no cylinder pressure relief device during filling, which may make it difficult to exhaust the gas in the cylinder, which will affect the filling of liquid chlorine and the quality of liquid chlorine after filling. Summary of the invention

[0006] The first technical problem to be solved by the present invention is to provide a liquid chlorine cylinder automatic filling device which can automatically fill liquid chlorine cylinders, has good quality of liquid chlorine after filling, and is safe and convenient in view of the current status of the prior art.

[0007] The second technical problem to be solved by the present invention is to provide an automatic filling method for liquid chlorine cylinders using the above-mentioned automatic filling device for liquid chlorine cylinders.

[0008] The technical solution adopted by the present invention to solve the first technical problem is: an automatic filling device for liquid chlorine cylinders, characterized in that it includes a filling system, a control system, an exhaust gas evacuation system and a pressure relief system;

[0009] The filling system comprises a liquid chlorine storage tank, an electromagnetic regulating valve, a filling needle valve and a steel cylinder, the steel cylinder is provided with an inlet needle valve and an outlet needle valve, the inlet needle valve is connected with a filling pipe, the outlet needle valve is connected with an evacuation pipe, the liquid chlorine storage tank, the electromagnetic regulating valve, the filling needle valve and the filling pipe are connected in series in sequence through a filling pipeline, a first branch is connected between the filling pipe and the evacuation pipe, and a connecting valve is provided on the first branch;

[0010] The control system includes a scale and a system management device, the scale is arranged below the steel cylinder to weigh the weight of the steel cylinder, and the system management device is electrically connected to the electromagnetic regulating valve and the scale respectively;

[0011] The exhaust gas evacuation system includes an evacuation needle valve and an exhaust gas treatment device, wherein the evacuation pipe, the evacuation needle valve and the exhaust gas treatment device are sequentially connected in series through an evacuation pipeline; a second branch is connected to the evacuation pipeline between the evacuation pipe and the evacuation needle valve, and pressure gauges are sequentially arranged on the second branch;

[0012] The pressure relief system includes a pressure relief valve and a pressure relief storage tank. The evacuation pipe, the pressure relief valve and the pressure relief storage tank are connected in series in sequence through a pressure relief pipeline. A third branch is connected between the pressure relief storage tank and the liquid chlorine storage tank. A fourth branch is connected between the pressure relief storage tank and the tail gas treatment device, and a safety valve is provided on the fourth branch.

[0013] Preferably, the number of the liquid chlorine storage tanks is at least two, and the liquid chlorine storage tanks are arranged in parallel with each other, with one tank in operation and the others in standby.

[0014] Furthermore, a lower liquid valve and a filling main valve are sequentially arranged on the filling pipeline between the liquid chlorine storage tank and the electromagnetic regulating valve. The number of the lower liquid valves corresponds to the number of the liquid chlorine storage tanks and is arranged on the parallel branch of the corresponding liquid chlorine storage tanks. The number of the filling main valve is one, which is connected in series with each lower liquid valve. Such an arrangement can ensure that each liquid chlorine storage tank works independently.

[0015] Furthermore, a balancing valve and a vent valve are sequentially arranged on the third branch. The number of the vent valves corresponds to the number of the liquid chlorine storage tanks and is arranged on the parallel branches of the corresponding liquid chlorine storage tanks. The number of the balancing valve is one, which is connected in series with each vent valve.

[0016] Preferably, the electromagnetic regulating valve is in an open state when the power is on and in a closed state when the power is off, and the electromagnetic regulating valve is provided with a manual switch that can control its opening and closing. Such a setting can ensure that chlorine gas does not leak when the electromagnetic regulating valve fails.

[0017] Preferably, the tail gas treatment device comprises a nanopump, a sodium hydroxide falling film absorption tower and a sodium hypochlorite storage tank connected in series. These devices can maintain a negative pressure in the tail gas system, and safely react the chlorine in the tail gas with sodium hydroxide to generate a sodium hypochlorite solution, and finally meet the national environmental protection emission standards.

[0018] Preferably, the safety valve value of the safety valve is -5kPa to -10kPa (gauge pressure). Such a setting can ensure that the chlorine pipeline and the pressure relief storage tank are at a slight negative pressure, which can prevent chlorine leakage on the one hand and ensure the safe operation of the tail gas treatment device on the other hand.

[0019] The technical solution adopted by the present invention to solve the second technical problem is: an automatic filling method for liquid chlorine steel cylinders using the above-mentioned automatic filling device for liquid chlorine steel cylinders, comprising the following steps:

[0020] (1) Evacuate the cylinder: Turn on the power of the system management device, place the cylinder on the scale, connect the inlet needle valve of the cylinder to the filling pipe, connect the outlet needle valve of the cylinder to the evacuation pipe, open the evacuation needle valve, inlet needle valve and outlet needle valve, and the exhaust gas treatment device extracts the gas in the cylinder until the pressure gauge shows that the absolute value of the vacuum degree is 15-25kPa, and then close the evacuation needle valve;

[0021] (2) Automatic filling: Set the scale to zero, open the electromagnetic regulating valve, the filling needle valve and the pressure relief valve, and fill the liquid chlorine in the liquid chlorine storage tank into the cylinder. The residual gas in the cylinder enters the pressure relief tank, and the air pressure in the pressure relief tank increases. A part of the gas in the pressure relief tank returns to the liquid chlorine storage tank through the third branch. When the air pressure in the pressure relief tank exceeds the safety threshold of the safety valve, the safety valve trips, and a part of the gas in the pressure relief tank is extracted to the tail gas treatment device. When the liquid chlorine in the cylinder is filled to 90%, the system management device automatically alarms and gradually closes the electromagnetic regulating valve until the filling is completed, and closes the filling needle valve, the inlet needle valve, the outlet needle valve and the pressure relief valve;

[0022] (3) Pipeline evacuation: Open the connecting valve and the evacuation needle valve. The exhaust gas treatment device extracts the residual gas from part of the filling pipeline, the filling pipe, the evacuation pipe, the evacuation pipeline and part of the pressure relief pipeline until the pressure gauge shows that the absolute value of the vacuum degree is 15 to 25 kPa. Close the connecting valve and the evacuation needle valve.

[0023] Preferably, the method further comprises the following steps: when the liquid chlorine storage tank fails or needs maintenance, the safety valve is manually controlled to open so that the residual gas in the liquid chlorine storage tank is discharged into the tail gas treatment device.

[0024] Compared with the prior art, the advantages of the present invention are:

[0025] (1) Before filling, the residual gas in the cylinder is exhausted through the tail gas evacuation system to improve the quality of liquid chlorine after filling;

[0026] (2) Automatic filling of liquid chlorine can be achieved by controlling the opening and closing of the electromagnetic regulating valve through the system management device;

[0027] (3) During the filling process, the excess gas in the cylinder is stored in the pressure relief storage tank in the pressure relief system, and part of the gas in the pressure relief storage tank returns to the liquid chlorine storage tank through the third branch, so that the chlorine gas is recovered while the gas pressure in the pressure relief storage tank is stabilized. When the gas pressure in the pressure relief storage tank exceeds the safety threshold of the safety valve, the safety valve trips, and part of the gas in the pressure relief storage tank is extracted to the tail gas treatment device, so as to further ensure the stability of the gas pressure in the pressure relief storage tank;

[0028] In summary, the automatic filling device and method for liquid chlorine cylinders of the present invention can automatically fill liquid chlorine cylinders, and the liquid chlorine after filling is of good quality, safe and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The figure is a schematic structural diagram of an embodiment of the automatic filling device for liquid chlorine cylinders of the present invention. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below with reference to the accompanying drawings.

[0031] like Figure 1 FIG. 1 is a preferred embodiment of the automatic filling device for liquid chlorine steel cylinders of the present invention. The automatic filling device for liquid chlorine steel cylinders comprises a filling system 1, a control system 2, an exhaust gas evacuation system 3 and a pressure relief system 4.

[0032] The filling system 1 includes a liquid chlorine storage tank 11, a liquid discharge valve 12, a filling main valve 13, an electromagnetic regulating valve 14, a filling needle valve 15, a steel cylinder 16 and a connecting valve 17. Specifically, the steel cylinder 16 is provided with an inlet needle valve 161 and an outlet needle valve 162, the inlet needle valve 161 is connected to a filling pipe 1611, the outlet needle valve 162 is connected to an evacuation pipe 1621, and the liquid chlorine storage tank 11, the liquid discharge valve 12, the filling main valve 13, the electromagnetic regulating valve 14, the filling needle valve 15 and the filling pipe 1611 are sequentially connected in series through a filling pipeline 10. In this embodiment, there are two liquid chlorine storage tanks 11, and each liquid chlorine storage tank 11 is arranged in parallel with each other, one in operation and one in standby; the number of lower liquid valves 12 corresponds to the number of liquid chlorine storage tanks 11, and is arranged on the parallel branch of the corresponding liquid chlorine storage tank 11; the number of filling main valves 13 is one, which is connected in series with each lower liquid valve 12. A first branch is connected between the filling pipe 1611 and the evacuation pipe 1621, and a connecting valve 17 is arranged on the first branch. The electromagnetic regulating valve 14 is in an open state when the power is on and in a closed state when the power is off. The electromagnetic regulating valve 14 can adjust the opening according to the progress of the filling, and the switching process is relatively smooth. On the one hand, it can improve the working conditions of the electromagnetic regulating valve and extend the service life of the electromagnetic regulating valve; on the other hand, it can reduce the filling error and improve the filling accuracy. In addition, a manual switch that can control its opening and closing is provided on the electromagnetic regulating valve 14 to prevent accidents when the electromagnetic regulating valve 14 fails, thereby improving the overall reliability of the system.

[0033] The control system 2 includes a scale 21 and a system management device 22. Specifically, the scale 21 is disposed below the steel cylinder 16 to weigh the weight of the steel cylinder 16, and the system management device 22 is electrically connected to the electromagnetic regulating valve 14 and the scale 21, respectively.

[0034] The system management device 22 has a filling button, a zeroing button, an emergency filling stop button, an electronic display function of the cylinder weight, a warning function for the completion of filling, an automatic adjustment function of the electromagnetic regulating valve, and an automatic cut-off function of the leakage alarm, wherein: the filling button can control the electromagnetic regulating valve 14 to open, the zeroing button can control the scale 21 to zero, the emergency filling stop button can control the electromagnetic regulating valve 14 to close, the electronic display function of the cylinder weight refers to displaying the real-time value of the scale 21, the warning function for the completion of filling refers to automatic warning when the filling reaches 90%; the automatic adjustment function of the electromagnetic regulating valve refers to gradually reducing the opening of the electromagnetic regulating valve 14 in a linear form when the filling reaches 90%, and closing it when the filling is completed; the automatic cut-off function of the leakage alarm detects the increase in the mass of the cylinder 16 during the filling process. If the mass of the cylinder 16 does not increase within 5 seconds when the electromagnetic regulating valve 14 is opened, the electromagnetic regulating valve 14 will be automatically closed.

[0035] The tail gas evacuation system 3 includes an evacuation needle valve 31 and a tail gas treatment device 32. Specifically, the evacuation pipe 1621, the evacuation needle valve 31 and the tail gas treatment device 32 are sequentially connected in series through the evacuation pipeline 30; the evacuation pipeline 30 between the evacuation pipe 1621 and the evacuation needle valve 31 is connected to a second branch, and a pressure gauge valve 33 and a pressure gauge 34 are sequentially arranged on the second branch. In this embodiment, the tail gas treatment device 32 includes a nanopump, a sodium hydroxide falling film absorption tower and a sodium hypochlorite storage tank connected in series with each other. The nanopump plays a role in evacuation. The nanopump uses 98% concentrated sulfuric acid as the working medium to ensure that the residual chlorine water content is low. The sodium hydroxide falling film absorption tower plays a role in absorbing chlorine. The sodium hydroxide solution can react with chlorine to generate sodium hypochlorite, which is finally passed into the sodium hypochlorite storage tank for storage.

[0036] The pressure relief system 4 includes a pressure relief valve 41, a pressure relief storage tank 42, a balancing valve 43, a vent valve 44 and a safety valve 45. Specifically, the evacuation pipe 1621, the pressure relief valve 41 and the pressure relief storage tank 42 are connected in series in sequence through the pressure relief pipeline 40; a third branch is connected between the pressure relief storage tank 42 and the liquid chlorine storage tank 11, and the balancing valve 43 and the vent valve 44 are arranged on the third branch in sequence. The number of the vent valves 44 corresponds to the number of the liquid chlorine storage tanks 11, and is arranged on the parallel branch of the corresponding liquid chlorine storage tanks 11. The number of the balancing valve 43 is one, which is connected in series with each vent valve 44; a fourth branch is connected between the pressure relief storage tank 42 and the tail gas treatment device 32, and the safety valve 45 is arranged on the fourth branch. In this embodiment, the safety valve value of the safety valve 45 is -5kPa~-10kPa (gauge pressure).

[0037] The pressure relief system 4 has the functions of stabilizing the gas pressure in the steel cylinder, balancing the gas pressure in the liquid chlorine storage tank, emptying the faulty storage tank, and regulating the pressure of the pressure relief tank, wherein: the function of stabilizing the gas pressure in the steel cylinder refers to sending the excess gas in the steel cylinder 14 to the pressure relief tank 42 for storage during filling; the function of balancing the gas pressure in the liquid chlorine storage tank refers to connecting the pressure relief tank 42 with the liquid chlorine storage tank 11, and stabilizing the pressure of the liquid chlorine storage tank 11 through the balancing valve 43; the function of emptying the faulty storage tank refers to closing the lower liquid valve 12 corresponding to the faulty liquid chlorine storage tank 11, closing the vent valves 44 corresponding to the remaining liquid chlorine storage tanks 11, and manually opening the safety valve 45, so that the residual gas in the faulty liquid chlorine storage tank 11 can be emptied to the exhaust gas treatment device 32; the function of regulating the pressure of the pressure relief tank refers to when the pressure of the pressure relief tank 42 is too high, part of the gas can be sent to the liquid chlorine storage tank 11 through the balancing valve 43, and part of the gas can be sent to the exhaust gas treatment device 32 through the safety valve 45, thereby stabilizing the gas pressure of the pressure relief tank 42.

[0038] In addition, the material of each pipeline and branch is copper, 16Mn or stainless steel, which is resistant to low temperature and prevents severe corrosion by liquid chlorine. In this embodiment, the material of each pipeline and branch is 16Mn.

[0039] The present invention also provides a method for automatically filling a liquid chlorine steel cylinder using the automatic filling device for the liquid chlorine steel cylinder.

[0040] Embodiment 1:

[0041] Preparation:

[0042] The first step is the inspection before filling. Each cylinder 16 to be filled is inspected and the residual chlorine weight is weighed with an electronic crane scale. The cylinders 16 that meet the requirements are subjected to subsequent residual chlorine purity analysis, and the cylinders that do not meet the requirements are handled accordingly to prevent the occurrence of subsequent filling accidents;

[0043] Among them, the cylinders that do not meet the requirements include: the steel stamp mark and color mark do not meet the regulations and the gas in the cylinder cannot be determined; the modification does not meet the regulations or the user modifies it by himself; there is no residual pressure in the cylinder; the inspection period has exceeded; there is obvious damage on the appearance; there is no certificate of conformity; the cylinder is stained with grease; the safety accessories are incomplete or damaged;

[0044] The second step is residual chlorine analysis. For the steel cylinder 16 that has passed the inspection, the safety cap and the hexagonal copper cap are removed, the outlet needle valve 162 is slightly opened, and the outlet needle valve 162 is immediately closed after a small amount of gas is released. Ammonia water is sprayed on the steel cylinder for color discrimination test. If white mist is generated, it proves that there is chlorine in the bottle. The steel cylinder 16 with chlorine is analyzed for residual chlorine purity. The steel cylinder with a purity of 90% is subjected to subsequent chlorine extraction operation. The unqualified steel cylinder is treated accordingly to prevent the occurrence of filling accidents and the quality of liquid chlorine products from being unqualified.

[0045] The third step is to extract chlorine from the cylinder. Connect the cylinder 16 that has passed the residual chlorine purity analysis to the chlorine extraction pipe, open the outlet needle valve 162, and extract chlorine under the condition that the absolute value of the working vacuum is greater than 12kPa;

[0046] The fourth step is to repair the bottle mouth. Add the PTFE gasket to the clean chlorine-extracted cylinder 16, tighten the small flange and the thimble, tighten the large flange, leave 3 to 5 threads after tightening, and install the hexagonal cap;

[0047] (1) Evacuating the cylinder: Turn on the power of the system management device 22, place the cylinder 16 on the scale 21, connect the inlet needle valve 161 of the cylinder 16 to the filling pipe 1611, connect the outlet needle valve 162 of the cylinder 16 to the evacuation pipe 1621, open the evacuation needle valve 31, the inlet needle valve 161 and the outlet needle valve 162, and the exhaust gas treatment device 32 extracts the gas in the cylinder 16 until the pressure gauge 34 shows that the absolute value of the vacuum degree is 20 kPa, and then close the evacuation needle valve 31;

[0048] (2) Automatic filling: The scale 21 is set to zero, the electromagnetic regulating valve 14, the filling needle valve 15 and the pressure relief valve 41 are opened, and the liquid chlorine in the liquid chlorine storage tank 11 is filled into the steel cylinder 16. The residual gas in the steel cylinder 16 enters the pressure relief storage tank 42, and the air pressure in the pressure relief storage tank 42 increases. A part of the gas in the pressure relief storage tank 42 returns to the liquid chlorine storage tank 11 through the third branch. When the air pressure in the pressure relief storage tank 42 exceeds the safety threshold value of the safety valve 45, the safety valve 45 trips, and a part of the gas in the pressure relief storage tank 42 is extracted to the exhaust gas treatment device 32. When the liquid chlorine in the steel cylinder 16 is filled to 90%, the system management device 22 automatically warns and gradually closes the electromagnetic regulating valve 14 until the filling is completed, and closes the filling needle valve 15, the inlet needle valve 161, the outlet needle valve 162 and the pressure relief valve 41;

[0049] (3) Pipeline evacuation: Open the connecting valve 17 and the evacuation needle valve 31. The exhaust gas treatment device 32 extracts the residual gas in part of the filling pipeline 10, the filling pipe 1611, the evacuation pipe 1621, the evacuation pipeline 30 and part of the pressure relief pipeline 40 until the pressure gauge 34 shows that the absolute value of the vacuum degree is 20 kPa. Then close the connecting valve 17 and the evacuation needle valve 31.

[0050] The cylinder 16 that has been automatically filled is lifted by a crane to a special scale for re-weighing. The cylinders within the error range of -5kg to +5kg are stored later, and those exceeding the allowable error range are immediately handled accordingly.

[0051] After the final filling, the volume fraction of chlorine in the cylinder 16 is 99.85%, which meets the quality indicators of superior products in the national standard GB / T5138 for industrial liquid chlorine.

[0052] Embodiment 2:

[0053] The difference from Example 1 is that:

[0054] In step (1), until the absolute value of the vacuum degree displayed by the pressure gauge 34 is 25 kPa, the evacuation needle valve 31 is closed;

[0055] In step (3), until the pressure gauge 34 shows that the absolute value of the vacuum degree is 25 kPa, the connecting valve 17 and the evacuation needle valve 31 are closed.

[0056] After the final filling, the volume fraction of chlorine in the cylinder 16 is 99.91%, which meets the quality indicators of superior products in the national standard GB / T5138 for industrial liquid chlorine.

[0057] Embodiment 3:

[0058] The difference from Example 1 is that:

[0059] In step (1), until the absolute value of the vacuum degree indicated by the pressure gauge 34 is 15 kPa, the evacuation needle valve 31 is closed;

[0060] In step (3), until the pressure gauge 34 shows that the absolute value of the vacuum degree is 15 kPa, the connecting valve 17 and the evacuation needle valve 31 are closed.

[0061] After the final filling, the volume fraction of chlorine in the cylinder 16 is 99.82%, which meets the quality indicators of superior products in the national standard GB / T5138 for industrial liquid chlorine.

[0062] Comparative Example 1:

[0063] The difference from Example 1 is that step (1) is deleted.

[0064] After the final filling, the volume fraction of chlorine in the cylinder 16 was 99.54%, which did not meet the quality indicators of qualified products in the national standard GB / T5138 for industrial liquid chlorine.

[0065] Comparative Example 2:

[0066] The difference from Example 1 is that the pressure relief system 4 is deleted, that is, the pressure relief valve 41 and the balance valve 43 are always in a closed state during the filling process.

[0067] After the final filling, the volume fraction of chlorine in the cylinder 16 is 99.68%, which only meets the quality indicators of qualified products and first-class products in the national standard GB / T5138 for industrial liquid chlorine.

[0068] From the above data, we can see that:

[0069] (1) It can be seen from Examples 1 to 3 that appropriately increasing the vacuum degree during chlorine gas evacuation can increase the volume fraction of chlorine in the filled cylinder 16 to a certain extent. In actual production, it is necessary to comprehensively consider the operating energy consumption and product quality;

[0070] (2) It can be seen from Comparative Examples 1, 2 and Example 1 that exhausting the residual gas in the steel cylinder 16 by the tail gas evacuation system 3 before filling can improve the quality of the liquid chlorine after filling, and releasing the pressure of the gas in the steel cylinder 16 by the pressure relief system 4 during filling can also improve the quality of the liquid chlorine after filling. The combination of evacuation and pressure relief can make the volume fraction of chlorine in the steel cylinder 16 meet the quality indicators of superior products in the national standard GB / T 5138 for industrial liquid chlorine.

Claims

1. An automatic filling device for liquid chlorine cylinders, characterized in that: It comprises a filling system (1), a control system (2), an exhaust gas evacuation system (3) and a pressure relief system (4); The filling system (1) comprises a liquid chlorine storage tank (11), an electromagnetic regulating valve (14), a filling needle valve (15) and a steel cylinder (16); the steel cylinder (16) is provided with an inlet needle valve (161) and an outlet needle valve (162); the inlet needle valve (161) is connected to a filling pipe (1611); the outlet needle valve (162) is connected to an evacuation pipe (1621); the liquid chlorine storage tank (11), the electromagnetic regulating valve (14), the filling needle valve (15) and the filling pipe (1611) are sequentially connected in series through a filling pipeline (10); a first branch is connected between the filling pipe (1611) and the evacuation pipe (1621); a connecting valve (17) is provided on the first branch; The control system (2) comprises a scale (21) and a system management device (22), wherein the scale (21) is arranged below the steel cylinder (16) for weighing the weight of the steel cylinder (16), and the system management device (22) is electrically connected to the electromagnetic regulating valve (14) and the scale (21) respectively; The exhaust gas evacuation system (3) comprises an evacuation needle valve (31) and an exhaust gas treatment device (32); the evacuation pipe (1621), the evacuation needle valve (31) and the exhaust gas treatment device (32) are sequentially connected in series via an evacuation pipeline (30); a second branch is connected to the evacuation pipeline (30) between the evacuation pipe (1621) and the evacuation needle valve (31), and pressure gauges (34) are sequentially arranged on the second branch; The pressure relief system (4) comprises a pressure relief valve (41) and a pressure relief storage tank (42); the evacuation pipe (1621), the pressure relief valve (41) and the pressure relief storage tank (42) are sequentially connected in series via a pressure relief pipeline (40); a third branch is connected between the pressure relief storage tank (42) and the liquid chlorine storage tank (11); a fourth branch is connected between the pressure relief storage tank (42) and the tail gas treatment device (32), and a safety valve (45) is provided on the fourth branch; The number of the liquid chlorine storage tanks (11) is at least two, and the liquid chlorine storage tanks (11) are arranged in parallel with each other; A lower liquid valve (12) and a filling main valve (13) are sequentially arranged on the filling pipeline (10) between the liquid chlorine storage tank (11) and the electromagnetic regulating valve (14); the number of the lower liquid valves (12) corresponds to the number of the liquid chlorine storage tanks (11) and is arranged on the parallel branch of the corresponding liquid chlorine storage tank (11); the number of the filling main valve (13) is one and is connected in series with each lower liquid valve (12); The third branch is provided with a balancing valve (43) and a vent valve (44) in sequence. The number of the vent valves (44) corresponds to the number of the liquid chlorine storage tanks (11) and is provided on the parallel branch of the corresponding liquid chlorine storage tanks (11). The number of the balancing valve (43) is one and is connected in series with each vent valve (44).

2. The automatic filling device for liquid chlorine cylinder according to claim 1 is characterized in that: The electromagnetic regulating valve (14) is in an open state when power is on and in a closed state when power is off, and a manual switch capable of controlling the opening and closing of the electromagnetic regulating valve (14) is provided on the electromagnetic regulating valve (14).

3. The automatic filling device for liquid chlorine cylinder according to claim 1 is characterized in that: The tail gas treatment device (32) comprises a nanopump, a sodium hydroxide falling film absorption tower and a sodium hypochlorite storage tank which are connected in series.

4. The automatic filling device for liquid chlorine cylinders according to any one of claims 1 to 3, characterized in that: The safety valve value of the safety valve (45) is a gauge pressure of -5 kPa to -10 kPa.

5. A method for automatically filling a liquid chlorine cylinder using the automatic filling device for a liquid chlorine cylinder as claimed in any one of claims 1 to 4, comprising the following steps: (1) Evacuating the cylinder: Turn on the power supply of the system management device (22), place the cylinder (16) on the scale (21), connect the inlet needle valve (161) of the cylinder (16) to the filling pipe (1611), connect the outlet needle valve (162) of the cylinder (16) to the evacuation pipe (1621), open the evacuation needle valve (31), the inlet needle valve (161) and the outlet needle valve (162), and the exhaust gas treatment device (32) extracts the gas in the cylinder (16) until the pressure gauge (34) shows that the absolute value of the vacuum degree is 15~25kPa, and then close the evacuation needle valve (31); (2) Automatic filling: Set the scale (21) to zero, open the electromagnetic regulating valve (14), the filling needle valve (15) and the pressure relief valve (41), and fill the liquid chlorine in the liquid chlorine storage tank (11) into the steel cylinder (16). The residual gas in the steel cylinder (16) enters the pressure relief storage tank (42), and the gas pressure in the pressure relief storage tank (42) increases. A part of the gas in the pressure relief storage tank (42) returns to the liquid chlorine storage tank (11) through the third branch. When the gas in the pressure relief storage tank (42) When the gas pressure exceeds the safety threshold value of the safety valve (45), the safety valve (45) trips, and a portion of the gas in the pressure relief storage tank (42) is extracted to the tail gas treatment device (32). When the liquid chlorine in the cylinder (16) is filled to 90%, the system management device (22) automatically issues an alarm and gradually closes the electromagnetic regulating valve (14) until the filling is completed, and closes the filling needle valve (15), the inlet needle valve (161), the outlet needle valve (162) and the pressure relief valve (41); (3) Pipeline evacuation: Open the connecting valve (17) and the evacuation needle valve (31), and the exhaust gas treatment device (32) extracts the residual gas in part of the filling pipeline (10), the filling pipe (1611), the evacuation pipe (1621), the evacuation pipeline (30) and part of the pressure relief pipeline (40) until the pressure gauge (34) shows that the absolute value of the vacuum degree is 15~25kPa, and then close the connecting valve (17) and the evacuation needle valve (31).

6. The method for automatically filling a liquid chlorine cylinder according to claim 5, characterized in that The method further comprises the following steps: when the liquid chlorine storage tank (11) fails or needs maintenance, the safety valve (45) is manually controlled to open so that the residual gas in the liquid chlorine storage tank (11) is discharged into the tail gas treatment device (32).

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