Liquid closed feeding device and feeding method

Abstract

The invention belongs to the field of chemical production equipment, and particularly relates to a liquid closed feeding device and a feeding method. The liquid closed feeding device comprises a pressure control part and a feeding part, the pressure control part comprises a first three-way pipe provided with a valve and a pressure gauge, and the feeding part comprises a second three-way pipe provided with a valve, a third three-way pipe provided with a valve and a fourth three-way pipe provided with a valve; the first three-way pipe comprises a first pipeline, a second pipeline and a third pipeline, a first valve and a pressure gauge are arranged on the first pipeline, and a second valve is arranged on the third pipeline; the second three-way pipe comprises a fourth pipeline, a fifth pipeline and a sixth pipeline, a third valve is arranged on the fifth pipeline, and a fourth valve is arranged on the sixth pipeline; the third three-way pipe comprises a seventh pipeline, an eighth pipeline and a ninth pipeline, the fourth pipeline is communicated with the eighth pipeline, and a fifth valve is arranged on the pipeline for communicating the fourth pipeline with the eighth pipeline; and one pipeline of the fourth three-way pipe is communicated with the seventh pipeline, and the other two pipelines of the fourth three-way pipe are respectively provided with a sixth valve and a seventh valve.

Description

Technical Field

[0001] The invention belongs to the field of chemical production equipment, and in particular relates to a liquid closed feeding device and a feeding method. Background Art

[0002] In the production activities of chemical, biological and medical industries, it is often necessary to add flammable, explosive, toxic or inactivated liquid materials in contact with air. These liquid materials are required to be sealed during the feeding process. Air pumps are generally used in factories, and the liquid delivery volume is not high and is mainly intermittent. When replacing material barrels, frequent purging and replacement are required, which not only increases the probability of residual liquid in the pipeline coming into contact with air to produce flammable and explosive gases or failure, but also greatly increases the danger of operation and material loss.

[0003] The nitrogen pressure device is a traditional device used for adding flammable and explosive liquids. During use, the nitrogen inside the device is usually passed into the solvent barrel through an air pump, thereby pressing the solvent into the reactor. Before the solvent barrel is replaced, the solvent filling pipeline will be replaced and cleaned with nitrogen or inert solvent.

[0004] Patent application CN113332929A discloses a nitrogen pressurized liquid feeding device. The material is stored in a tank with only one bottom-inserted tube. When discharging the material, nitrogen is first pressed into the tank through the bottom-inserted tube to increase the pressure in the tank, and then the material is pressed out of the bottom-inserted tube to the use device through the pressure in the tank. The device can complete the liquid feeding operation under closed conditions to avoid odor leakage.

[0005] Authorized patent CN216077492U discloses a nitrogen pressure device for flammable and explosive liquids. When in use, nitrogen is first sucked into the nitrogen tank, and then the servo motor pushes the rubber push plate to press the nitrogen in the nitrogen tank into the solvent tank through the exhaust pipe, thereby pressing the solvent into the reactor.

[0006] Most of the existing flammable and explosive liquids are filled by nitrogen pressure injection. However, due to regulatory requirements, many manufacturers use barreled and multi-batch transportation to avoid the storage of high-risk chemicals posing a major hazard source. This will result in frequent installation, purging, replacement, and disassembly of hazardous chemical barrels. The probability of flammable, explosive, and toxic chemicals being exposed to the air when wet is greatly increased. However, there are always dead corners inside the pipeline, and too long purging and replacement time will also lead to increased nitrogen consumption.

[0007] Patent application CN113332929A and authorized patent CN216077492U both first inhale nitrogen and then use nitrogen to press out the solvent. The solvent can only enter the reactor in an intermittent manner, not continuously, resulting in poor metering accuracy.

[0008] In addition, patent application CN113332929A fails to solve the problem of how to pre-exhaust the residual air in the first pipe 4 when the device is first operated. Patent CN216077492U also fails to solve the problem of residual air in the pipe connecting the exhaust pipe 8 and the solvent barrel when the device is first used. Summary of the invention

[0009] The object of the present invention is to provide a liquid sealed feeding device and a feeding method.

[0010] In a first aspect of the present invention, a liquid sealed feeding device is provided, comprising a pressure control part and a feeding part, wherein the pressure control part comprises a first three-way pipe provided with a valve and a pressure gauge, and the feeding part comprises a second three-way pipe provided with a valve, a third three-way pipe provided with a valve, and a fourth three-way pipe provided with a valve;

[0011] The first three-way pipe includes a first pipeline, a second pipeline and a third pipeline, the first pipeline is provided with a first valve and the pressure gauge, and the third pipeline is provided with a second valve;

[0012] The second three-way pipe includes a fourth pipeline, a fifth pipeline and a sixth pipeline, the fifth pipeline is provided with a third valve, and the sixth pipeline is provided with a fourth valve;

[0013] The third three-way pipe includes a seventh pipeline, an eighth pipeline and a ninth pipeline, the fourth pipeline is connected to the eighth pipeline, and a fifth valve is provided on the pipeline connecting the fourth pipeline and the eighth pipeline;

[0014] One pipeline of the fourth three-way pipe is connected to the seventh pipeline, and the other two pipelines of the fourth three-way pipe are respectively provided with a sixth valve and a seventh valve.

[0015] In one or more embodiments, the outlet end of the second pipeline is provided with a first flange connected to the liquid hazardous chemical storage tank, and the outlet end of the ninth pipeline is provided with a second flange connected to the liquid hazardous chemical storage tank.

[0016] In one or more embodiments, the third conduit extends into the second conduit, extends within the second conduit, and extends from the first flange; and / or the eighth conduit extends into the ninth conduit, extends within the ninth conduit, and extends from the second flange.

[0017] In one or more embodiments, the second pipeline is connected to a nitrogen source through a tenth pipeline, and the first pipeline is connected to a vacuum pipeline through an eleventh pipeline.

[0018] In one or more embodiments, the second pipeline is connected to the vacuum pipeline through a tenth pipeline, and the first pipeline is connected to the nitrogen source through an eleventh pipeline.

[0019] In one or more embodiments, the pipeline provided with the sixth valve in the fourth three-way pipe is connected to the vacuum pipeline through the twelfth pipeline, and the pipeline provided with the seventh valve in the fourth three-way pipe leads to the reactor through the thirteenth pipeline.

[0020] In one or more embodiments, the pipeline provided with the sixth valve in the fourth three-way pipe leads to the reaction kettle through the twelfth pipeline, and the pipeline provided with the seventh valve in the fourth three-way pipe is connected to the vacuum pipeline through the thirteenth pipeline.

[0021] In one or more embodiments, the sixth pipeline is connected to the nitrogen source through a fourteenth pipeline, and the fifth pipeline is connected to the material / washing liquid pipeline through a fifteenth pipeline.

[0022] In one or more embodiments, the sixth pipeline is connected to the material / washing liquid pipeline through a fourteenth pipeline, and the fifth pipeline is connected to the nitrogen source through a fifteenth pipeline.

[0023] A second aspect of the present invention provides a liquid closed feeding system, which includes the liquid closed feeding device described in the first aspect of the present invention and a liquid hazardous chemical storage tank.

[0024] In one or more embodiments, the eighth valve is connected to a sixteenth pipe extending into the liquid hazardous chemicals storage tank, and the sixteenth pipe does not extend into the liquid surface in the liquid hazardous chemicals storage tank.

[0025] In one or more embodiments, the ninth valve is connected to a seventeenth pipe extending into the liquid hazardous chemicals storage tank, and the seventeenth pipe extends into the bottom of the liquid hazardous chemicals storage tank.

[0026] The third aspect of the present invention provides a method for conveying liquid hazardous chemicals using the liquid closed feeding system according to the second aspect of the present invention, comprising the steps of:

[0027] (1) purging the liquid closed feeding device with nitrogen;

[0028] (2) increasing the pressure in the liquid hazardous chemical storage tank so that the liquid hazardous chemical is transported into the reactor;

[0029] (3) reducing the pressure in the liquid hazardous chemical storage tank so that the liquid in the seventh pipeline flows back into the liquid hazardous chemical storage tank;

[0030] (4) Adjust the positive pressure in the liquid hazardous chemical storage tank;

[0031] (5) using the material / washing liquid to flush the fifteenth pipeline, the fifth pipeline, the fourth pipeline, the fifth valve, the eighth pipeline, the ninth pipeline, the seventh pipeline, the seventh valve, and the thirteenth pipeline;

[0032] (6) Allow nitrogen to purge the fifth pipeline, the fourth pipeline, the sixth pipeline, the eighth pipeline, the ninth pipeline, the seventh pipeline, the fifth valve, the ninth valve, and the seventh valve.

[0033] In one or more embodiments, the liquid hazardous chemical is selected from one or more of chlorosulfonic acid, triisobutylaluminum, pentaborane, triethylaluminum, dimethylzinc, phosphorus trioxide, toluene diisocyanate, arsenic trichloride and isovaleryl chloride.

[0034] In one or more embodiments, step (1) includes backflushing the fifteenth conduit with nitrogen.

[0035] In one or more embodiments, in step (3), the pressure in the liquid hazardous chemicals storage tank is -0.05 to -0.005 MPa (G).

[0036] In one or more embodiments, in step (4), the pressure in the liquid hazardous chemicals storage tank is 0.01 to 0.05 MPa (G).

[0037] Compared with the traditional barrel feeding method, the liquid closed feeding device of the present invention has the following characteristics:

[0038] (1) It can be filled continuously or intermittently, with higher flexibility in filling; the device is directly connected to the nitrogen pipeline, without the need for intermediate devices such as nitrogen storage tanks, and the nitrogen gas source is stable and continuous;

[0039] (2) No liquid filling loss: by adding the material into the reactor in two or more batches, the flammable and explosive liquid remaining in the pipeline is flushed into the reactor, completing the work of flushing the flammable and explosive liquid from the feeding pipeline;

[0040] (3) Low purge gas consumption, more complete replacement, and low disassembly and installation risks; the combination of vacuuming, nitrogen replacement, material flushing, and excess liquid reflux can eliminate the "dead zone" liquid in the filling pipeline without the need for long-term purge and replacement;

[0041] (4) The structure is simple, the operation is simple, and the price is low. It is assembled using valves, tees, and pressure gauges, and does not require additional air pumps, nitrogen tanks, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the overall structure of the liquid closed feeding device of the present invention.

[0043] Figure 2 It is a structural schematic diagram of the pressure control part of the liquid closed feeding device of the present invention.

[0044] Figure 3 It is a structural schematic diagram of the feeding part of the liquid closed feeding device of the present invention.

[0045] Description of reference numerals:

[0046] The first pipeline 205b, the second pipeline 205a, the third pipeline 204, the fourth pipeline 306a, the fifth pipeline 306b, the sixth pipeline 306c, the seventh pipeline 304a, the eighth pipeline 304b, the ninth pipeline 304c, the tenth pipeline 202, the eleventh pipeline 207, the twelfth pipeline 312, the thirteenth pipeline 302, the fourteenth pipeline 310, the fifteenth pipeline 308, the sixteenth pipeline 102, the seventeenth pipeline 105;

[0047] The first valve 206, the second valve 203, the third valve 307, the fourth valve 309, the fifth valve 305, the sixth valve 311, the seventh valve 303, the eighth valve 103, and the ninth valve 106;

[0048] First flange-201, second flange-301;

[0049] Pressure gauge-208. DETAILED DESCRIPTION

[0050] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0051] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0052] Herein, “comprising”, “including”, “containing” and similar terms encompass the meanings of “consisting essentially of” and “consisting of”. For example, when “A comprises B and C” is disclosed herein, “A consists essentially of B and C” and “A consists of B and C” should be deemed to be disclosed herein.

[0053] In this article, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are only for brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0054] In this document, unless otherwise specified, percentage refers to mass percentage and ratio refers to mass ratio.

[0055] Herein, when describing embodiments or examples, it should be understood that they are not used to limit the present invention to these embodiments or examples. On the contrary, all substitutes, improvements and equivalents of the methods and materials described in the present invention can be included in the scope limited by the claims.

[0056] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0057] The liquid referred to in the present invention refers to a liquid that exists in liquid form when feeding and must be isolated from the environment, including but not limited to: liquids that are explosive when wet or exposed to air (such as chlorosulfonic acid, triisobutylaluminum, pentaborane), liquids that are burning when wet or exposed to air (such as triethylaluminum, dimethylzinc), liquids that are poisoning when wet or exposed to air (such as phosphorus trioxide, toluene diisocyanate), liquids that produce hydrogen chloride when wet or exposed to air (such as arsenic trichloride, isovaleryl chloride), liquids that fail when wet or exposed to air, etc. In this article, "liquid", "liquid hazardous chemicals" and "flammable and explosive liquids" have the same meaning. In some embodiments, the liquid hazardous chemicals are metal organic reagents, such as alkyl aluminum, alkyl zinc, alkyl magnesium, etc.

[0058] Herein, the pipe can be made of materials commonly used in the art, such as metal or non-metal. In order to prevent static electricity accumulation and improve the safety of the device, metal pipes are preferred. The pipe can be connected by a hose, a hard pipe, or a mixture of a hard and soft pipe.

[0059] Herein, the liquid-tight charging device and the liquid-tight charging system of the present invention can be manually operated or controlled by an automated program. In some embodiments, the liquid-tight charging device and / or the liquid-tight charging system of the present invention also include electronic equipment for controlling the liquid-tight charging device and / or the liquid-tight charging system.

[0060] Herein, the nitrogen purge at each stage may be performed for a conventional purge time in the art, such as 5 to 100 seconds, preferably 5 to 20 seconds.

[0061] In the prior art, the filling of flammable and explosive liquids is mostly carried out by air pumps or nitrogen tanks, and the nitrogen pipeline in the workshop does not directly contact the material tank, so the feeding capacity is greatly limited. The present invention directly connects the nitrogen pipe to the flammable and explosive chemical tank, and the feeding capacity is not limited.

[0062] The present invention provides a new liquid sealed feeding device, which can realize the sealed feeding of liquid. During the use of the device, as long as the operation is proper, no hazardous chemicals will remain in the place where the hazardous chemical storage tank is connected to the pipeline. It can not only isolate the liquid from the air during the switching process of the hazardous chemical storage tank to achieve sealing; it can also realize continuous filling, and can fill a large amount of liquid in a short time; it can also return the residual liquid in the "dead zone" in the pipeline to the hazardous chemical storage tank, and the liquid remaining in the pipeline is brought into the reactor through partial raw material flushing, reducing the material filling loss to zero.

[0063] In some embodiments, such as Figure 1-3 As shown in FIG. 1 , the liquid sealed feeding device of the present invention includes two parts: pressure control and feeding. The structure of the pressure control part is as follows: Figure 2 As shown in FIG. 1 , the structure of the pressure control part includes a three-way pipe with two valves and a pressure gauge. Figure 3 As shown, the structure of the feeding part is a combination of a three-way pipe and a valve.

[0064] like Figure 1 As shown, the pressure control part is connected to the valve 103 of the hazardous chemical storage tank 101 through the flange 201, and the valve 103 is also connected to the pipeline 102 extending into the hazardous chemical storage tank 101, and the pipeline 102 does not extend into the liquid surface in the hazardous chemical storage tank 101. The feeding part is connected to the valve 106 of the hazardous chemical storage tank 101 through the flange 301, and the valve 106 is also connected to the pipeline 105 extending into the hazardous chemical storage tank 101, and the pipeline 105 extends into the bottom of the hazardous chemical storage tank 101.

[0065] The diameter of the nitrogen inlet pipe 204 is smaller than that of the pipe 205, and the pipe 204 is divided into two parts, one inside the pipe 205 and the other outside the pipe 205, which are connected through the pipe wall of the pipe 205. The part of the pipe 204 inside the pipe 205 and the part of the pipe 204 outside the pipe 205 can be connected by conventional processing methods in the art, such as welding, according to the materials of the pipe 204 and the pipe 205. The connection point between the inner and outer parts of the pipe 204 divides the pipe 205 into two parts, 205a and 205b. The pipe opening of the pipe 204 inside the pipe 205a should extend from the flange 201. The length of the pipe 204 inside the pipe 205a should not affect the connection between the flange 201 and the valve 103. The purpose of the pipe extension is to allow the nitrogen to blow directly into the valve core of the valve 103, so that the nitrogen replacement is more sufficient. The pipeline 204 enters the interior of the pipeline 205a by bending, and the outlet extends out of the flange 201, as close as possible to the valve core of the valve 103, so that the nitrogen purge is more sufficient without leaving a "dead zone". In practical applications, the angle of the bend is determined according to the setting angle of the pipeline 204 and the pipeline 205a, and it is only necessary to meet the requirement that the portion of the pipeline 204 that bends to enter the interior of the pipeline 205a maintains the same extension direction as the pipeline 205a. In some embodiments, the pipeline 204 is arranged parallel to the horizontal plane, the pipeline 205a is arranged perpendicular to the horizontal plane, and the pipeline 204 bends 90 degrees to enter the interior of the pipeline 205a. Preferably, a similar structure can also be arranged in the pipeline 304c above the valve 106, that is, compared with the pipeline 304c, the pipeline 304b that passes nitrogen has a smaller diameter, and the pipeline 304b penetrates into the pipeline 304c and extends out of the flange 301.

[0066] After installing the device, first make sure all valves are in the closed position.

[0067] When in use, first open valve 206, connect the three-way pipe to the vacuum pipe, remove the gas inside the three-way pipe, observe the reading of pressure gauge 208, then open valve 203 to connect nitrogen, nitrogen enters from pipe 204, blows directly into valve 103 valve core, and then nitrogen flows upward from valve 206 through the annular gap between pipe 204 and pipe 205 to the vacuum system. The purge lasts for 5 to 20 seconds, then first close valve 206, and at the same time reduce the opening of valve 203, observe the gradual increase of the pressure gauge reading, and when the pressure gauge reading rises to 0.01 to 0.05 MPa (G), close valve 203. The nitrogen replacement work of the three-way pipe is completed.

[0068] Then, valve 311 and valve 305 are opened in sequence to make pipeline 304 and pipeline 306 in a vacuum state. After 5 to 20 seconds, valve 311 is closed, and valve 309 and valve 303 are opened in sequence to replace nitrogen. Nitrogen goes to the reactor through pipeline 302. After 5 to 20 seconds, valve 303, valve 305 and valve 309 are closed in sequence. Thus, all pipelines are replaced with nitrogen.

[0069] Pipeline 308 is always filled with material / washing liquid. If the material / washing liquid is switched, there may be air inside pipeline 308. At this time, first confirm that valve 305 is in the closed state, then open valve 309 and valve 307 in sequence to allow nitrogen to backflush pipeline 308.

[0070] After the entire liquid-sealed feeding device is replaced by nitrogen, it can be used to transport flammable and explosive liquid materials stored in the hazardous chemical storage tank 101. First, record the reading of the pressure gauge 208, and then slowly open the valve 103 until the pressure gauge reading changes slightly. When the pressure gauge reading decreases, it indicates that the internal pressure of the hazardous chemical storage tank 101 is insufficient. At this time, slowly open the valve 203 to add nitrogen to the tank. Always pay attention to the pressure gauge 208. When the pressure gauge reading rises to the point where the material in the tank can be pressed out into the reactor, open valves 303 and 106 in turn. At this time, the flammable and explosive liquid materials in the tank are continuously fed into the reactor.

[0071] When the feeding work in the tank is completed, first close valve 203 to stop the gas supply. Then close valve 106 first, and then open valve 309 and valve 305 in sequence. At this time, the nitrogen will purge the flammable and explosive liquid remaining in the pipeline into the reactor for 5 to 20 seconds. Then close valve 305 and valve 309 in sequence. At this time, there will be a section of flammable and explosive liquid remaining in the pipeline 304c.

[0072] In order to return the hazardous substances in the pipe 304c to the hazardous chemicals storage tank 101 for easy disassembly, first slowly open the valve 206 to a small angle below 20° (such as 5°) to slowly evacuate the inside of the hazardous chemicals storage tank 101. When the pressure gauge 208 reading changes to -0.05 to -0.005 MPa (G), close the valve 206, open the valve 106, and let the liquid in the pipe 304c flow back to the hazardous chemicals storage tank 101. Thus, the liquid material in the pipe 304c is processed. Close the valve 106, open the valve 203, and when the pressure gauge 208 reading slowly rises to 0.01 to 0.05 MPa (G), close the valve 103 to keep a slight positive pressure inside the hazardous chemicals storage tank 101 to prevent the danger of air being sucked back due to negative pressure. Finally, close the valve 203.

[0073] In order to ensure that the inflammable and explosive liquid does not remain inside the pipe 304 and the pipe 302, the pipe needs to be flushed with materials or washing liquid. Open valve 307 and valve 305 in sequence, and the material / washing liquid will enter the reactor / washing liquid collection tank along pipe 308, pipe 306b, pipe 306a, valve 305, pipe 304b, pipe 304a, valve 303, and pipe 302. The material / washing liquid fills the entire device, and the residual inflammable and explosive liquid is diluted, and no safety hazard occurs.

[0074] After the material / washing liquid is flushed, first close valve 307, then open valve 309 to purge nitrogen for 10 to 20 seconds to prevent leakage of residual liquid when disassembling flange 301. Then close valve 309, and flange 201 and flange 301 can be safely disassembled, so that the liquid-tight feeding device is separated from the hazardous chemical storage tank 101.

[0075] In some embodiments, the pipeline 205a is connected to a nitrogen source via pipeline 202, and the pipeline 205b is connected to a vacuum pipeline via pipeline 207. In other embodiments, the pipeline 205a is connected to a vacuum pipeline via pipeline 202, and the pipeline 205b is connected to a nitrogen source via pipeline 207.

[0076] In some embodiments, the pipeline provided with valve 311 in the fourth three-way pipe is connected to the vacuum pipeline through pipeline 312, and the pipeline provided with valve 303 in the fourth three-way pipe leads to the reactor through pipeline 302. In other embodiments, the pipeline provided with valve 311 in the fourth three-way pipe leads to the reactor through pipeline 312, and the pipeline provided with valve 303 in the fourth three-way pipe is connected to the vacuum pipeline through pipeline 302.

[0077] In some embodiments, the pipeline 306c is connected to a nitrogen source via a pipeline 310, and the pipeline 306b is connected to a material / washing liquid pipeline via a pipeline 308. In other embodiments, the pipeline 306c is connected to a material / washing liquid pipeline via a pipeline 310, and the pipeline 306b is connected to a nitrogen source via a pipeline 308.

[0078] The present invention also provides a liquid closed feeding system, which comprises the liquid closed feeding device of the present invention and a liquid hazardous chemical storage tank.

[0079] The present invention also provides a method for conveying liquid hazardous chemicals using the liquid closed feeding system of the present invention, comprising the steps of:

[0080] (1) purging the liquid closed feeding device with nitrogen;

[0081] (2) increasing the pressure in the liquid hazardous chemical storage tank so that the liquid hazardous chemical is transported into the reactor;

[0082] (3) reducing the pressure in the liquid hazardous chemical storage tank so that the liquid in the pipeline (304a) flows back into the liquid hazardous chemical storage tank;

[0083] (4) Adjust the positive pressure in the liquid hazardous chemical storage tank;

[0084] (5) allowing the material / washing liquid to flush the pipeline (308), pipeline (306b), pipeline (306a), valve (305), pipeline (304b), pipeline (304c), pipeline (304a), valve (303), and pipeline (302);

[0085] (6) Allow nitrogen to purge pipeline (306b), pipeline (306a), pipeline (306c), pipeline (304b), pipeline (304c), pipeline (304a), valve (305), valve (106), and valve (303).

[0086] In some embodiments, step (1) includes backflushing the pipeline (308) with nitrogen.

[0087] In some embodiments, in step (3), the pressure in the liquid hazardous chemicals storage tank is -0.05 to -0.005 MPa (G).

[0088] In some embodiments, in step (4), the pressure in the liquid hazardous chemicals storage tank is 0.01 to 0.05 MPa (G).

[0089] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples without specifying specific conditions are usually based on conventional conditions or the conditions recommended by the manufacturer. Unless otherwise stated, percentages and parts are calculated by weight.

[0090] Example: Alkyl aluminum is added into a DCPD (dicyclopentadiene) reactor.

[0091] according to Figure 1-3 Build the liquid closed feeding device and carefully connect flange 201 and flange 301 to valve 103 and valve 106 respectively.

[0092] First, open valve 206, connect the vacuum pipe, remove the gas inside the tee, observe the reading of pressure gauge 208, then open valve 203 to connect nitrogen, nitrogen enters from pipe 204, and blows directly to the valve core of valve 103. Nitrogen then flows upward from the annular gap between pipes 204 and 205, and out of the vacuum system from valve 206.

[0093] After the purge continues for 5 to 20 seconds, first close valve 206 and at the same time reduce the opening of valve 203, and observe that the pressure gauge reading gradually increases. When the pressure gauge reading rises to 0.01 to 0.05 MPa (G), close valve 203.

[0094] Open valves 311 and 305 in sequence to put pipes 304 and 306 in a vacuum state. After 10 to 20 seconds, close valve 311.

[0095] Open valves 309 and 303 in sequence to replace with nitrogen. Nitrogen goes into the reactor through pipeline 302. After 5 to 20 seconds, valves 303, 305 and 309 are closed in sequence.

[0096] Slowly open valve 203 to add nitrogen to the hazardous chemical storage tank 101. Always pay attention to the pressure gauge 208. When the pressure gauge reading rises to a level that can press the alkyl aluminum in the tank into the reactor, open valves 303 and 106 in sequence, and the alkyl aluminum in the hazardous chemical storage tank 101 is continuously fed into the DCPD reactor.

[0097] When the feeding is finished, close valve 203 and stop the gas supply. Then close valve 106 first, and then open valves 309 and 305 in sequence. At this time, nitrogen will purge the alkyl aluminum liquid remaining in the pipeline into the DCPD reactor for 5 to 20 seconds. Then close valves 305 and 309 in sequence.

[0098] First, slowly open valve 206 to a small angle below 20° to slowly evacuate the interior of hazardous chemicals storage tank 101. When the pressure gauge 208 reading changes to -0.05 to -0.005 MPa (G), close valve 206.

[0099] Open valve 106 to allow the alkyl aluminum inside pipeline 304c to flow back into the hazardous chemical storage tank 101.

[0100] Close valve 106 and open valve 203. When the reading of pressure gauge 208 slowly rises to 0.01-0.05 MPa (G), close valve 103.

[0101] Close valve 203.

[0102] Open valves 307 and 305 in sequence to feed the remaining DCPD material into the reactor.

[0103] After the DCPD material delivery is completed, first close valve 307, and then open valve 309 to perform nitrogen purge for 5 to 20 seconds.

[0104] Close valve 309 , disassemble flange 201 and flange 301 , and disassemble the liquid-tight feeding device of the present invention from the hazardous chemical storage tank 101 .

Claims

1. A liquid closed feeding device, characterized in that: It includes a pressure control part and a feeding part, wherein the pressure control part includes a first three-way pipe provided with a valve and a pressure gauge, and the feeding part includes a second three-way pipe provided with a valve, a third three-way pipe provided with a valve, and a fourth three-way pipe provided with a valve; The first three-way pipe includes a first pipeline, a second pipeline and a third pipeline, the first pipeline is provided with a first valve and the pressure gauge, and the third pipeline is provided with a second valve; The second three-way pipe includes a fourth pipeline, a fifth pipeline and a sixth pipeline, the fifth pipeline is provided with a third valve, and the sixth pipeline is provided with a fourth valve; The third three-way pipe includes a seventh pipeline, an eighth pipeline and a ninth pipeline, the fourth pipeline is connected to the eighth pipeline, and a fifth valve is provided on the pipeline connecting the fourth pipeline and the eighth pipeline; One pipeline of the fourth three-way pipe is connected to the seventh pipeline, and the other two pipelines of the fourth three-way pipe are respectively provided with a sixth valve and a seventh valve.

2. The closed liquid feeding device according to claim 1, characterized in that: The outlet end of the second pipeline is provided with a first flange connected to the liquid hazardous chemical storage tank, and the outlet end of the ninth pipeline is provided with a second flange connected to the liquid hazardous chemical storage tank.

3. The closed liquid feeding device according to claim 2, characterized in that: The third pipe extends into the second pipe, extends inside the second pipe, and extends out from the first flange; and / or the eighth pipe extends into the ninth pipe, extends inside the ninth pipe, and extends out from the second flange.

4. The closed liquid feeding device according to claim 1, characterized in that: The second pipeline is connected to the nitrogen source through a tenth pipeline, and the first pipeline is connected to the vacuum pipeline through an eleventh pipeline; or The second pipeline is connected to the vacuum pipeline through the tenth pipeline, and the first pipeline is connected to the nitrogen source through the eleventh pipeline.

5. The liquid sealed feeding device according to claim 1, characterized in that: The pipeline provided with the sixth valve in the fourth three-way pipe is connected to the vacuum pipeline through the twelfth pipeline, and the pipeline provided with the seventh valve in the fourth three-way pipe leads to the reaction kettle through the thirteenth pipeline; or The pipeline provided with the sixth valve in the fourth three-way pipe leads to the reaction kettle through the twelfth pipeline, and the pipeline provided with the seventh valve in the fourth three-way pipe is connected to the vacuum pipeline through the thirteenth pipeline.

6. The closed liquid feeding device according to claim 1, characterized in that: The sixth pipeline is connected to the nitrogen source through the fourteenth pipeline, and the fifth pipeline is connected to the material / washing liquid pipeline through the fifteenth pipeline; or The sixth pipeline is connected to the material / washing liquid pipeline through the fourteenth pipeline, and the fifth pipeline is connected to the nitrogen source through the fifteenth pipeline.

7. A closed liquid feeding system, characterized in that: The liquid closed feeding system comprises the liquid closed feeding device and the liquid hazardous chemical storage tank according to any one of claims 1 to 6.

8. The closed liquid feeding system according to claim 7, characterized in that: The eighth valve is connected to a sixteenth pipeline extending into the liquid hazardous chemical storage tank, and the sixteenth pipeline does not extend into the liquid surface in the liquid hazardous chemical storage tank; The ninth valve is connected to a seventeenth pipeline extending into the liquid hazardous chemicals storage tank, and the seventeenth pipeline extends into the bottom of the liquid hazardous chemicals storage tank.

9. A method for conveying liquid hazardous chemicals using the liquid closed feeding system according to claim 7 or 8, characterized in that: Includes steps: (1) purging the liquid closed feeding device with nitrogen; (2) increasing the pressure in the liquid hazardous chemical storage tank so that the liquid hazardous chemical is transported into the reactor; (3) reducing the pressure in the liquid hazardous chemical storage tank so that the liquid in the seventh pipeline flows back into the liquid hazardous chemical storage tank; (4) Adjust the positive pressure in the liquid hazardous chemical storage tank; (5) using the material / washing liquid to flush the fifteenth pipeline, the fifth pipeline, the fourth pipeline, the fifth valve, the eighth pipeline, the ninth pipeline, the seventh pipeline, the seventh valve, and the thirteenth pipeline; (6) Allow nitrogen to purge the fifth pipeline, the fourth pipeline, the sixth pipeline, the eighth pipeline, the ninth pipeline, the seventh pipeline, the fifth valve, the ninth valve, and the seventh valve.

10. The method according to claim 9, characterized in that The method has one or more of the following features: The liquid hazardous chemicals are selected from one or more of chlorosulfonic acid, triisobutylaluminum, pentaborane, triethylaluminum, dimethylzinc, phosphorus trioxide, toluene diisocyanate, arsenic trichloride and isovaleryl chloride; Step (1) includes backflushing the fifteenth pipeline with nitrogen; In step (3), the pressure in the liquid hazardous chemicals storage tank is -0.05 to -0.005 MPa (G); In step (4), the pressure in the liquid hazardous chemicals storage tank is 0.01-0.05 MPa (G).

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