CN220194452U

CN220194452U - Acetylene drying device

Info

Publication number: CN220194452U
Application number: CN202321732409.3U
Authority: CN
Inventors: 黄彦华; 何利君; 仲文; 杨文义; 王佳贤
Original assignee: Alxa Dakang Tetrachloroethylene Co ltd
Current assignee: Alxa Dakang Tetrachloroethylene Co ltd
Priority date: 2023-07-04
Filing date: 2023-07-04
Publication date: 2023-12-19
Anticipated expiration: 2033-07-04

Abstract

The application provides an acetylene drying device. The device of this application is dry with the acetylene gas that contains water through setting up the drying tower to set up nitrogen gas pipeline and to dry tower blowback, regenerate drier in with the drying tower, resume the drying tower drying capacity, set up the buffer tank simultaneously and to the gaseous temporary storage and the cooling of blowing off in the opposite directions, set up the separation tower again with the nitrogen gas and the acetylene separation of blowing off in the opposite directions, and retrieve nitrogen gas and acetylene. The device of this application uses through the cooperation of above-mentioned equipment, with acetylene independent drying, has overcome the not thorough, the pipeline equipment scheduling problem of corruption of drying that current acetylene and hydrogen chloride hybrid drying brought. In addition, the drying tower can be recycled after regeneration, and the regenerated nitrogen can be recycled, so that the method has the characteristic of saving cost.

Description

Acetylene drying device

Technical Field

The application relates to the technical field of acetylene drying, in particular to an acetylene drying device.

Background

In the PVC (polyvinyl chloride ) production industry in China, the calcium carbide method for producing VCM (vinyl chloride monomer ) accounts for a considerable proportion, and the production method is relatively mature in process but relatively backward; the ages are also longer. However, at present, the international petroleum price is continuously high, and the calcium carbide method is a very new one by virtue of the relatively low production cost.

The method comprises the steps of washing acetylene produced by a calcium carbide method by hypochlorous acid to remove impurities such as phosphorus, sulfur and the like, neutralizing and removing sulfuric acid and phosphoric acid generated by the reaction by a sodium hydroxide neutralization tower, washing to remove alkali mixed in the acetylene, and finally outputting clean acetylene gas. The acetylene output from this process inevitably carries moisture which has a detrimental effect on the quality and yield of the subsequent VCM synthesis, and therefore must be available for VCM synthesis after drying of the acetylene.

Because acetylene and hydrogen chloride are raw materials for synthesizing VCM, the traditional method for drying acetylene is to mix acetylene and hydrogen chloride and then cool and dry, but hydrochloric acid is easy to form in the mode, pipeline equipment is corroded, the temperature needs to be controlled to be in a very low state (-35 ℃), the risk of blockage of pipeline icing is caused, and the water is difficult to be reduced to be very low in the mode; there is also a method of mixing acetylene with hydrogen chloride, cooling and drying, and then absorbing moisture by using concentrated sulfuric acid, but this method firstly generates a large amount of waste sulfuric acid, and secondly has the undesirable consequence that the concentrated sulfuric acid is blackened and blocks the pipe disc due to the carbonization of the concentrated sulfuric acid because other impurities are mixed in the gas. It is therefore necessary to propose a way of drying acetylene separately.

Disclosure of Invention

The application provides an acetylene drying device for separately drying acetylene, overcome the shortcoming of above-mentioned current bad result that brings acetylene and hydrogen chloride hybrid drying.

The application provides an acetylene drying device, which comprises an acetylene pipeline and a nitrogen pipeline, wherein the acetylene pipeline is sequentially connected with a drying tower and an acetylene storage tank in series;

the drying tower is connected with the acetylene storage tank through a first valve;

the nitrogen pipeline is connected with the heater through a second valve;

the output end of the heater is connected with the drying tower;

the drying tower is also connected with the buffer tank and the separation tower in series in sequence;

the separation tower is respectively connected with the acetylene storage tank and the nitrogen pipeline;

and a third valve is arranged between the drying tower and the buffer tank.

Optionally, a first filter is provided between the acetylene line and the drying column.

Optionally, a second filter is further arranged between the buffer tank and the third valve of the separation tower.

Optionally, the drying tower is divided into a lower cooling area and an upper dewatering area by a perforated partition plate;

a cooling coil is arranged in the cooling zone, and a drying agent is filled in the dehydration zone;

the side edge of the drying tower, which is positioned in the cooling area, is respectively provided with an acetylene inlet, a back-blowing gas outlet and a liquid outlet;

the acetylene inlet is positioned between the cooling coil and the bottom of the drying tower;

the acetylene inlet is connected with an acetylene pipeline; the back-blowing gas outlet is connected with a third valve;

the top of the drying tower is provided with a nitrogen inlet and an acetylene outlet;

the nitrogen inlet is connected with the second valve;

the acetylene outlet is connected with the first valve;

the bottom of the side surface of the dewatering area is provided with a discharge hole.

Optionally, a moisture detector is arranged at 3/5-1 of the height of the dehydration zone.

Optionally, the shape of the perforated baffle is a conical surface, and the angle of the vertex angle is 90-150 degrees.

Alternatively, the desiccant is a 3A molecular sieve.

The device of this application is dry with the acetylene gas that contains water through setting up the drying tower to set up nitrogen gas pipeline and to dry tower blowback, regenerate drier in with the drying tower, resume the drying tower drying capacity, set up the buffer tank simultaneously and to the gaseous temporary storage and the cooling of blowing off in the opposite directions, set up the separation tower again with the nitrogen gas and the acetylene separation of blowing off in the opposite directions, and retrieve nitrogen gas and acetylene. The device of this application uses through the cooperation of above-mentioned equipment, with acetylene independent drying, has overcome the not thorough, the pipeline equipment scheduling problem of corruption of drying that current acetylene and hydrogen chloride hybrid drying brought. In addition, the drying tower can be recycled after regeneration, and the regenerated nitrogen can be recycled, so that the method has the characteristic of saving cost.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief description will be given below of the drawings that are needed in the embodiments or the prior art descriptions, and it is obvious that the drawings in the following description are some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic view of an acetylene drying apparatus according to an embodiment of the present disclosure;

fig. 2 is a schematic view of an acetylene drying apparatus according to another embodiment of the present application;

fig. 3 is a schematic view of an acetylene drying apparatus according to another embodiment of the present application;

fig. 4 is a schematic structural diagram of a drying tower according to an embodiment of the present disclosure;

fig. 5 is a schematic structural diagram of a drying tower according to another embodiment of the present disclosure.

Reference numerals illustrate:

1. acetylene pipeline; 2. a drying tower; 3. an acetylene storage tank; 4. a nitrogen line; 5. a heater; 6. a buffer tank; 7. a separation tower; 8. a first filter; 9. a second filter; 21. a separator plate with holes; 22. a cooling coil; 23. a moisture detector; 100. a first valve; 200. a second valve; 201. an acetylene inlet; 202. a blowback gas outlet; 203. a liquid outlet; 204. a nitrogen inlet; 205. an acetylene outlet; 206. a discharge port; 300. and a third valve.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application are clearly and completely described below, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without inventive effort, are also within the scope of the present application based on the embodiments herein.

As shown in fig. 1, the present application provides an acetylene drying device, which comprises an acetylene pipeline 1 and a nitrogen pipeline 4, wherein the acetylene pipeline 1 is connected with a drying tower 2 and an acetylene storage tank 3 in series;

the drying tower 2 and the acetylene storage tank 3 are connected through a first valve 100;

the nitrogen pipeline 4 is connected with the heater 5 through a second valve 200;

the output end of the heater 5 is connected with the drying tower 2;

the drying tower 2 is also connected with a buffer tank 6 and a separation tower 7 in series in turn;

the separation tower 7 is respectively connected with the acetylene storage tank 3 and the nitrogen pipeline 4;

a third valve 300 is also provided between the drying tower 2 and the buffer tank 6.

When the device of the application works normally, the equipment passing through when acetylene is dried is an acetylene pipeline 1, a drying tower 2 and an acetylene storage tank 3.

When regenerating the drying tower 2, the devices passed through are a nitrogen pipeline 4, a heater 5, the drying tower 2, a buffer tank 6 and a separation tower 7; the separation tower 7 inputs the separated nitrogen into the nitrogen pipeline 4 and the acetylene gas into the acetylene storage tank 3.

The buffer tank 6 is provided with a heat exchange jacket to exchange heat and cool the gas entering the buffer tank 6, and heat exchange media in the jacket after heat exchange can be used for heating other working sections so as to reduce energy waste.

The separation tower 7 is used for separating nitrogen and acetylene gas, and can separate the nitrogen and the acetylene gas in a pressure swing adsorption mode, and the separated acetylene gas and nitrogen are in a pure state, so that the nitrogen can be directly returned to a nitrogen pipeline, and the acetylene gas is conveyed to the acetylene storage tank 3.

An acetylene drying device has the following working process:

in normal use, the second valve 200 and the third valve 300 are closed, and the first valve 100 is opened. The aqueous acetylene from acetylene line 1 enters drying column 2. The aqueous acetylene gas introduced into the drying column 2 is removed by trapping moisture in the acetylene gas by a drying agent (in this case, 3A molecular sieve) filled in the drying column 2, to obtain a dried acetylene gas. The dried acetylene gas is discharged from the drying tower 2 and enters the acetylene storage tank 3 for temporary storage.

Regeneration of the drying tower 2: when it is detected that the water content of the acetylene gas discharged from the drying tower 2 exceeds a preset value (for example, 50 ppm), the acetylene line 1 stops supplying the acetylene gas, and at this time, the regeneration stage of the drying tower 2 is entered. Closing the first valve 100; the second valve 200 and the third valve 300 are opened. Nitrogen cold blowing is carried out (the heater 5 is not started in the cold blowing process), nitrogen is blown out by the nitrogen pipeline 4, acetylene gas in the drying tower 2 is blown out through entering the drying tower, and the acetylene gas enters the buffer tank 6 through the third valve 300 for temporary storage.

After nitrogen gas is cold-blown for 1-2 hours, the heater 5 is turned on to perform nitrogen gas hot-blowing. Nitrogen is blown out from the nitrogen pipeline 4, heated to 80-90 ℃ by the heater 5, then enters the drying tower 2 for back blowing, residual acetylene gas in a drying agent (3A molecular sieve in the application) is discharged, the discharged gas enters the buffer tank 6 through the third valve 300 and is combined with the nitrogen cold-blown gas, after cooling, the acetylene gas and the nitrogen are separated in the separation tower 7, the separated nitrogen is returned to the nitrogen pipeline 4 for recycling, and the separated acetylene gas is input into the acetylene storage tank 3 for temporary storage.

When the content of acetylene in the gas discharged by nitrogen cold blowing of the drying tower 2 is detected to be lower than a preset value, such as 0.5%, molecular sieve dehydration is carried out, nitrogen is blown out by the nitrogen pipeline 4, the nitrogen is heated to 270-280 ℃ by the heater 5 and then enters the drying tower 2 for back blowing, the moisture in the drying agent (3A molecular sieve in the application) is removed, the blown high-temperature water-containing nitrogen is cooled by the buffer tank 6 (room temperature), the nitrogen is input into the separation tower 7 for separation, the separated nitrogen is returned to the nitrogen pipeline 4 for recycling, and the separated acetylene gas is input into the acetylene storage tank 3 for temporary storage. The heat exchange medium of the buffer tank 6 after the high-temperature nitrogen is cooled can be used for heating other working sections needing to be heated so as to utilize the heat in the working sections and reduce the energy waste. And when the temperature of the bed layer of the whole drying area reaches 250-270 ℃, ending the molecular sieve dehydration process. At this time, the drying tower 2 can be cooled naturally or cooled by nitrogen cold blowing.

The device of this application is through setting up drying tower 2 with the acetylene gas that contains water drying to set up nitrogen gas pipeline 4 and to dry tower 2 blowback, regenerate drier in with drying tower 2, resume drying tower drying capacity, set up buffer tank 6 simultaneously and to the gas temporary storage and the cooling of blowback, set up again that separator 7 will be blowback nitrogen gas and acetylene separation, and retrieve nitrogen gas and acetylene. The device of this application uses through the cooperation of above-mentioned equipment, with acetylene independent drying, has overcome the not thorough, the pipeline equipment scheduling problem of corruption of drying that current acetylene and hydrogen chloride hybrid drying brought. In addition, the drying tower can be recycled after regeneration, and the regenerated nitrogen can be recycled, so that the method has the characteristic of saving cost.

As shown in fig. 2, optionally, a first filter 8 is provided between the acetylene line 1 and the drying column 2.

In the present application, although the acetylene gas output from the acetylene line 1 is purified, there are trace amounts of impurities such as hydrogen sulfide and phosphine, and in order to avoid adverse effects of these impurities on the drying agent in the drying tower 2, a first filter 8 is provided between the acetylene line 1 and the drying tower 2 to remove these impurities, thereby protecting the drying agent.

As shown in fig. 3, optionally, a second filter 9 is further provided between the third valve buffer tank 6 and the separation column 7.

In this application, the desiccant adsorbs impurities in acetylene when adsorbing water, and therefore, when back-blowing and regenerating the desiccant in the drying tower 2, the substances adsorbed in the desiccant are blown out to avoid adverse effects of the impurities on the subsequent separation tower 7, and therefore, a second filter 9 is provided between the buffer tank 6 and the separation tower 7 to remove the impurities, thereby protecting the separation tower 7.

As shown in fig. 4, optionally, the drying tower 2 is divided into a lower cooling zone and an upper dewatering zone by a perforated partition 21;

a cooling coil 22 is arranged in the cooling zone, and a drying agent is filled in the dehydration zone;

the side edge of the drying tower 2, which is positioned in the cooling area, is respectively provided with an acetylene inlet 201, a back-blowing gas outlet 202 and a liquid outlet 203;

acetylene inlet 201 is located between cooling coil 22 and the bottom of drying column 2;

acetylene inlet 201 is connected to acetylene line 1;

the blowback gas outlet 202 is connected to the third valve 300;

the top of the drying tower 2 is provided with a nitrogen inlet 204 and an acetylene outlet 205;

the nitrogen inlet 204 is connected with the second valve 200;

the acetylene outlet 205 is connected to the first valve 100;

the bottom of the side of the dewatering zone is provided with a discharge opening 206.

An acetylene inlet 201 is connected to the acetylene line 1 for inputting an aqueous acetylene gas into the drying column 2; the acetylene outlet 205 is connected to the first valve 100, and is used for transferring the dried acetylene gas into the acetylene storage tank 3 through the first valve 100 for storage.

The nitrogen inlet 204 is connected with the second valve 200, and is used for blowing nitrogen into the drying tower 2 to blow back the drying agent in the drying agent regeneration stage; the blowback gas outlet 202 is connected to the third valve 300, and is configured to discharge the gas obtained by blowback of nitrogen gas to the desiccant in the drying tower 2 into the buffer tank 6.

Because acetylene contains water, condensate is produced after cooling through cooling coil 22, which can fall to the bottom of the column, where drain 203 is provided to drain the condensate.

The drain 206 is used to drain the desiccant when the desiccant in the desiccant area is replaced.

In this application, the dehydration zone is filled with a desiccant, such as a 3A molecular sieve.

In this application, the perforated partition 21 serves to support the desiccant and to separate the cooling zone from the drying zone.

The cooling coil 22 is arranged in the cooling area, the cooling medium in the cooling coil 22 is low-temperature frozen brine at 0-5 ℃, and the cooling area can not only pre-remove part of water in the aqueous acetylene gas by condensation, reduce the treatment burden of the drying agent in the drying area and prolong the service cycle of the drying agent in the drying area; and the acetylene gas can be cooled, so that the temperature generated when the moisture in the acetylene gas is adsorbed by the molecular sieve is reduced, and the stable drying process is facilitated.

As shown in fig. 5, a moisture detector 23 is optionally provided at 3/5 to 1 of the height of the dehydration zone.

In the present application, the moisture detector 23 is disposed in the drying tower 2 to detect the moisture in the discharged acetylene gas, so as to indicate whether the drying agent is deactivated, thereby prompting the operator to regenerate the drying agent in the drying tower 2. In a preferred embodiment, the moisture detector 23 is disposed at 3/5 to 1/3 of the height of the dehydration zone to prevent the filled drying agent from being completely deactivated by penetration, resulting in the occurrence of an adverse effect of excessively high water content of the acetylene gas outputted from the drying tower 2.

As shown in fig. 5, the perforated partition 21 may alternatively be in the shape of a conical surface with an angle of 90 to 150 ° at its apex angle.

In this application, when the desiccant in the drying tower 2 needs to be replaced, the perforated baffle 21 with a conical surface shape can facilitate the desiccant to be discharged from the discharge port 206 by self weight, and the angle of the vertex angle is 90-150 ° so as to reduce the height of the perforated baffle 21 with a conical surface shape, avoid the too high height, cause the central part of the desiccant to be prematurely penetrated and deactivated, affect the service cycle of the drying tower, and in a preferred mode, the angle of the vertex angle is 120-150 °.

Alternatively, the desiccant is a 3A molecular sieve.

In this application, the drier is 3A molecular sieve, has following advantage: the influence of temperature on the water absorption capacity is far smaller than that of a common desiccant (such as silica gel); the wet acetylene flow rate has little influence on the adsorption capacity of the molecular sieve; the water absorption capacity is larger than that of other desiccants (such as silica gel) under the condition of the same humidity.

An acetylene drying device has the following working process:

in normal use, the second valve 200 and the third valve 300 are closed, and the first valve 100 is opened. The aqueous acetylene from acetylene line 1 is filtered through a first filter 8 to remove impurities therein. From acetylene inlet 201 into drying column 2. The water-containing acetylene gas entering the drying tower 2 passes through the cooling coil 22 in the cooling zone from bottom to top, and low-temperature frozen brine with the temperature of 0-5 ℃ flows in the cooling coil 22. The water in the water-containing acetylene is condensed due to the temperature reduction, the water in the water-containing acetylene is primarily removed, and the condensed water is discharged from the liquid outlet 203 to the wastewater treatment section for treatment. The acetylene gas with water removed primarily in the cooling zone enters the drying zone through the perforated baffle plate 21, and the acetylene gas entering the drying zone is removed by intercepting the water in the acetylene gas through the 3A molecular sieve filled in the drying zone, so that the dried acetylene gas is obtained. The dried acetylene gas is discharged from the acetylene outlet 205 into the acetylene storage tank 3 for temporary storage.

When the drying tower 2 is regenerated and the moisture detector 23 in the drying zone detects that the moisture content exceeds a preset value (for example, 50 ppm), the acetylene line 1 stops supplying acetylene gas, and the cooling coil 22 stops introducing chilled brine. At this point, the regeneration stage of the drying tower 2 is entered. Closing acetylene inlet 201, first valve 100; the second valve 200 and the third valve 300 are opened. Nitrogen cold blowing is carried out (the heater 5 is not started in the cold blowing process), nitrogen is blown out by the nitrogen pipeline 4, acetylene gas in the drying tower 2 is blown out through entering the drying tower, and the acetylene gas enters the buffer tank 6 through the back blowing gas outlet 202 through the third valve 300 for temporary storage.

After nitrogen gas is cold-blown for 1-2 hours, the heater 5 is turned on to perform nitrogen gas hot-blowing. Nitrogen is blown out from the nitrogen pipeline 4, heated to 80-90 ℃ by the heater 5, then enters the drying tower 2 for back blowing, residual acetylene gas in the 3A molecular sieve is discharged, the discharged gas enters the buffer tank 6 through the third valve 300 and is combined with the gas blown by the nitrogen, after cooling, the gas is filtered by the second filter 9 and then is input into the separation tower 7 to separate the acetylene gas from the nitrogen, the separated nitrogen is returned to the nitrogen pipeline 4 for recycling, and the separated acetylene gas is input into the acetylene storage tank 3 for temporary storage.

When the content of acetylene in the gas blown out from the blowback gas outlet 202 is detected to be lower than a preset value, for example, 0.5%, molecular sieve dehydration is carried out, nitrogen is blown out from the nitrogen pipeline 4, the nitrogen is heated to 270-280 ℃ by the heater 5 and then enters the drying tower 2 for blowback, the moisture in the 3A molecular sieve is removed, the blown high-temperature water-containing nitrogen is cooled by the buffer tank 6 (room temperature), filtered by the second filter 9, and then is input into the separation tower 7 for separation, the separated nitrogen is returned to the nitrogen pipeline 4 for recycling, and the separated acetylene gas is input into the acetylene storage tank 3 for temporary storage. The heat exchange medium of the buffer tank 6 after the high-temperature nitrogen is cooled can be used for heating other working sections needing to be heated so as to utilize the heat in the working sections and reduce the energy waste. And when the temperature of the bed layer of the whole drying area reaches 250-270 ℃, ending the molecular sieve dehydration process. At this time, the drying tower 2 can be cooled naturally or cooled by nitrogen cold blowing.

When the desiccant in the drying tower 2 needs to be replaced, the discharge port 206 is opened to discharge the desiccant for replacement.

Finally, it should be noted that the above embodiments are merely for illustrating the technical solution of the present application, and are not limiting; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art will understand; the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. The acetylene drying device is characterized by comprising an acetylene pipeline (1) and a nitrogen pipeline (4), wherein the acetylene pipeline (1) is sequentially connected with a drying tower (2) and an acetylene storage tank (3) in series;

the drying tower (2) is connected with the acetylene storage tank (3) through a first valve (100);

the nitrogen pipeline (4) is connected with the heater (5) through a second valve (200);

the output end of the heater (5) is connected with the drying tower (2);

the drying tower (2) is also connected with the buffer tank (6) and the separation tower (7) in series in sequence;

the separation tower (7) is respectively connected with the acetylene storage tank (3) and the nitrogen pipeline (4);

a third valve (300) is further arranged between the drying tower (2) and the buffer tank (6).

2. Acetylene drying unit according to claim 1, characterized in that a first filter (8) is arranged between the acetylene line (1) and the drying column (2).

3. Acetylene drying device according to claim 1 or 2, characterized in that a second filter (9) is also arranged between the buffer tank (6) and the separation column (7).

4. Acetylene drying unit according to claim 1, characterized in that the drying column (2) is divided into a lower cooling zone and an upper dewatering zone by a perforated partition (21);

a cooling coil (22) is arranged in the cooling zone, and a drying agent is filled in the dehydration zone;

acetylene inlets (201), back-blowing gas outlets (202) and liquid discharge ports (203) are respectively formed in the side edges of the cooling areas of the drying towers (2);

the acetylene inlet (201) is positioned between the cooling coil (22) and the bottom of the drying tower (2);

the acetylene inlet (201) is connected with an acetylene pipeline (1); the back-flushing gas outlet (202) is connected with the third valve (300);

a nitrogen inlet (204) and an acetylene outlet (205) are formed in the top of the drying tower (2);

the nitrogen inlet (204) is connected with a second valve (200);

the acetylene outlet (205) is connected with the first valve (100);

a discharge outlet (206) is arranged at the bottom of the side surface of the dewatering area.

5. Acetylene drying unit according to claim 4, characterized in that a moisture detector (23) is arranged at 3/5-1 of the height of the dewatering zone.

6. Acetylene drying device according to claim 4 or 5, characterized in that the perforated baffle (21) is conical in shape and has an angle of the apex angle of 90-150 °.

7. The acetylene drying apparatus according to claim 4, wherein the drying agent is a 3A molecular sieve.