阅读说明：本技术 一种精馏法去除一氧化碳并集成高纯氮的氩气回收方法和装置 (Argon recovery method and device for removing carbon monoxide and integrating high-purity nitrogen by rectification method ) 是由 郝文炳 于 2019-12-10 设计创作，主要内容包括：本发明涉及一种精馏法去除一氧化碳并集成高纯氮的氩气回收方法,包括氩气回收流路和空气氮气流路。还涉及一种精馏法去除一氧化碳并集成高纯氮的氩气回收装置,包括氩气压缩机、一氧化碳反应炉、氩气预冷纯化系统、空气压缩机、空气预冷纯化系统、换热器、精氩塔、氩塔第一再沸器、氩塔第二再沸器、氩塔冷凝蒸发器、氮塔和氮塔冷凝蒸发器。本发明利用集成的空气氮气流路,通过利用液氩的富足冷量,冷箱内自产氮气可降低再生气的限制,提高回收氩气的提取率；并利用富裕的液氩冷量产部分液氮,提高经济效益。(The invention relates to an argon recovery method for removing carbon monoxide and integrating high-purity nitrogen by a rectification method. Still relate to an argon gas recovery unit that carbon monoxide was got rid of to rectification method and high pure nitrogen is integrated, including argon compressor, carbon monoxide reacting furnace, argon gas precooling purification system, air compressor, air precooling purification system, heat exchanger, smart argon tower, the first reboiler in argon tower, argon tower second reboiler, argon tower condensation evaporimeter, nitrogen tower and nitrogen tower condensation evaporimeter. According to the invention, by utilizing an integrated air nitrogen flow path and utilizing the rich cold quantity of liquid argon, the nitrogen produced in the cold box can reduce the limitation of regenerated gas and improve the extraction rate of recovered argon; and partial liquid nitrogen is produced by utilizing the cold energy of the abundant liquid argon, so that the economic benefit is improved.)

1. The utility model provides an argon gas recovery method of carbon monoxide is got rid of to rectification method and high-purity nitrogen is integrated, includes argon gas recovery flow path and air nitrogen gas flow path, its characterized in that:

the argon gas recovery flow path comprises the following steps:

s11, pressurizing the recovered argon by an argon compressor, removing oil and dust, and then feeding the argon into a carbon monoxide reaction furnace to remove oxygen in the argon; cooling the argon after deoxygenation by a cooler, and then, introducing the argon into an argon precooling and purifying system to remove water and carbon dioxide in the argon to obtain dry crude argon;

s12, feeding the dry crude argon into a rectification cold box, cooling to a liquefaction temperature through a heat exchanger, entering a first reboiler of an argon column arranged at the bottom of the argon rectification column, liquefying gas in the first reboiler of the argon column, gasifying liquid out of the first reboiler of the argon column through a throttling and pressure reducing part, and feeding the gasified liquid into the upper middle part of the argon rectification column to participate in rectification;

s13, feeding the gas-liquid mixed fluid into the fine argon tower, wherein the liquid part descends along with the liquid in the tower, and pure liquid argon is obtained at the bottom of the tower; pure liquid argon is pumped out from the bottom of the refined argon tower, throttled and depressurized and then sent to the evaporation side of the condensation evaporator of the argon tower, the pure liquid argon is evaporated into argon gas on the evaporation side of the condensation evaporator of the argon tower, and the argon gas is sent out of a rectification cold box after being reheated by a heat exchanger to recover cold energy;

s14, feeding the gas-liquid mixed fluid into the fine argon column, wherein the gas part rises along with the gas in the column, the gas at the top of the column mainly comprises carbon monoxide and nitrogen, and one part of the gas extracted from the top of the fine argon column enters a condensation evaporator of the argon column and is condensed into liquid and then fed into the fine argon column;

the air nitrogen flow path comprises the following steps:

s21, after being compressed by an air compressor, the air enters an air precooling and purifying system to remove water and carbon dioxide in the air; the dried air is cooled to the liquefaction temperature through a heat exchanger in a rectification cold box, and then is sent to the bottom of a nitrogen tower to provide rectification gas for the nitrogen tower;

s22, liquid-carrying air entering the bottom of the nitrogen column, wherein heavy components are accumulated in the liquid, and liquid oxygen-enriched air is obtained at the bottom of the column; wherein light components are accumulated in the gas, and high-purity nitrogen is obtained at the top of the tower;

s23, dividing the high-purity nitrogen extracted from the top of the nitrogen tower into two parts: sending the first part of nitrogen to the high-temperature side of a condensation evaporator of the nitrogen tower, cooling the nitrogen to liquid nitrogen, sending the cooled nitrogen back to the nitrogen tower, and participating in rectification of the nitrogen tower; the second part of nitrogen is sent out of the rectification cold box after being reheated by a heat exchanger to recover cold energy, and then is sent into an argon precooling and purifying system to be used as regeneration gas;

s24, after the pressure of the oxygen-enriched liquid air extracted from the bottom of the nitrogen tower is adjusted, the oxygen-enriched liquid air enters a nitrogen tower condensation evaporator to provide a cold source for the nitrogen tower, is vaporized into oxygen-enriched gas, exits the nitrogen tower condensation evaporator, then enters a heat exchanger for reheating, exits a rectifying cold box and is conveyed to an air precooling and purifying system to serve as dry gas.

2. The argon recovery method for removing carbon monoxide and integrating high-purity nitrogen through the rectification method according to claim 1, wherein in the step S11, the argon after being deoxidized is cooled to 35-40 ℃ through a cooler, then enters an argon precooling and purifying system, is cooled to 5-8 ℃ through an argon precooling machine, and enters an argon purifier to remove water and carbon dioxide, so that dry crude argon is obtained.

3. The argon recovery method for removing carbon monoxide and integrating high-purity nitrogen through rectification according to claim 1, wherein in step S13, make-up liquid argon from the outside of the rectification cold box enters the evaporation side of the condensation evaporator of the argon rectification column through a pipeline.

4. The argon recovery method for removing carbon monoxide and integrating high-purity nitrogen through rectification according to claim 1, wherein in the step S13, the argon sent out of the rectification cold box is divided into two parts: the first part of argon is used as argon product and can be pressurized or directly fed; and the second part of argon is taken as circulating gas, enters an argon circulating compressor for pressurization, is sent back to the rectifying cold box, is cooled by the heat exchanger, enters the argon tower second reboiler at the bottom of the fine argon tower, is liquefied therein, and is sent to the argon tower condensation evaporator for providing a cold source for the argon tower condensation evaporator after being depressurized.

5. The argon recovery method with carbon monoxide removed and high-purity nitrogen integrated by rectification according to claim 1, characterized in that in step S14, the gas extracted from the top of the argon rectification column is divided into two parts: the first part is sent out of the tower for emptying after being reheated by a heat exchanger to recover cold energy; and the second part of gas enters the gas side of the argon tower condensation evaporator to be condensed into liquid, flows into the argon refining tower and provides liquid for rectification.

6. The argon recovery method for removing carbon monoxide and integrating high-purity nitrogen through rectification according to claim 1, wherein in step S23, the first part of nitrogen is sent to the high-temperature side of the nitrogen tower condensation evaporator, cooled to liquid nitrogen, and then sent to the nitrogen tower to participate in rectification of the nitrogen tower, and the other part of liquid nitrogen can be taken as a byproduct and is extracted from the rectification cold box.

7. An argon recovery device for removing carbon monoxide and integrating high-purity nitrogen based on the rectification method of any one of claims 1 to 6, which is characterized by comprising an argon compressor, a carbon monoxide reaction furnace, an argon precooling and purifying system, an air compressor, an air precooling and purifying system, a heat exchanger, a refined argon tower, an argon tower first reboiler, an argon tower second reboiler, an argon tower condensation evaporator, a nitrogen tower and a nitrogen tower condensation evaporator; wherein:

the argon compressor is connected with the argon precooling and purifying system through the carbon monoxide reaction furnace by a pipeline, the argon compressor is used for pressurizing the recovered argon, the pressurized recovered argon is subjected to oxygen removal by the carbon monoxide reaction furnace and then is sent into the argon precooling and purifying system to be cooled to remove water and carbon dioxide in the argon;

the argon precooling and purifying system is connected with a first reboiler of the argon tower arranged at the bottom of the argon rectifying tower through a pipeline and the heat exchanger so as to cool the dry argon to the liquefaction temperature through the heat exchanger and send the dry argon into the first reboiler of the argon tower to form a gas-liquid mixed fluid, and the bottom of the first reboiler of the argon tower is communicated with the middle upper part of the argon rectifying tower through a pipeline so as to send the gas-liquid mixed fluid in the reboiler of the argon tower into the middle upper part of the argon rectifying tower to participate in rectification after pressure regulation;

the bottom of the fine argon tower is communicated with the argon tower condensation evaporator through a pipeline so as to pump pure liquid argon at the bottom of the fine argon tower to the evaporation side of the argon tower condensation evaporator and evaporate the pure liquid argon into argon at the evaporation side; the evaporation side of the argon tower condensation evaporator is communicated with the outside of the rectification cold box through a pipeline and the heat exchanger, so that argon on the evaporation side is reheated by the heat exchanger and then is sent out of the rectification cold box;

the pipeline out of the rectifying cold box is divided into two branches, wherein one branch can be directly connected with an argon product end or connected with an argon product end after being pressurized, and the other branch is connected with a second reboiler of the argon tower through a heat exchanger; so as to divide the argon sent out of the rectification cold box into two parts: a first portion of argon is used as an argon product; a second part of argon is taken as circulating gas and sent back to the rectification cold box, the circulating gas is cooled by a heat exchanger and then enters a second reboiler of the argon tower at the bottom of the fine argon tower, the argon is liquefied in the reboiler, and the argon is sent into a condensation evaporator of the argon tower after pressure reduction to provide a cold source for the argon tower;

the top of the argon refining tower is communicated with the argon precooling and purifying system through a heat exchanger rectification cold box and is communicated with the gas side of the argon tower condensation evaporator through a pipeline;

the gas withdrawn from the top of the fine argon column was divided into two parts: the first part is sent out of the tower for emptying after being reheated by a heat exchanger to recover cold energy; the second part of gas enters the gas side of the argon tower condensation evaporator to be condensed into liquid, flows into the argon refining tower and provides liquid for rectification;

the air compressor is connected with the air pre-cooling purification system through a pipeline, and air is pressurized by the air compressor and then sent into the air pre-cooling purification system so as to remove water and carbon dioxide in the air after being cooled;

the air pre-cooling purification system is communicated with the bottom of the nitrogen tower through a heat exchanger through a pipeline, so that dried air is cooled to a liquefaction temperature through the heat exchanger and then is sent to the bottom of the nitrogen tower, and rectification gas is provided for the nitrogen tower;

the top of the nitrogen tower is communicated with the argon pre-cooling and purifying system through a heat exchanger outlet rectification cold box and communicated with the high-temperature side of the nitrogen tower condensation evaporator through a pipeline; the gas extracted from the top of the nitrogen tower is divided into two parts, the first part is sent to the high-temperature side of the condensation evaporator of the nitrogen tower, after being cooled to liquid nitrogen, one part of the liquid nitrogen is sent to the top of the nitrogen tower through a pipeline to participate in rectification, and the other part of the liquid nitrogen is sent out of a rectification cold box through a pipeline; the second part is reheated by the heat exchanger and then is discharged from a rectification cold box and sent to the argon precooling and purifying system to be used as regeneration gas; and

the bottom of the nitrogen tower is communicated with the top of the nitrogen tower condensation evaporator through a pipeline; and the oxygen-enriched liquid air extracted from the bottom of the nitrogen tower enters the nitrogen tower condensation evaporator to provide a cold source for the nitrogen tower condensation evaporator after being subjected to pressure regulation, is vaporized into oxygen-enriched air, then enters the heat exchanger for reheating, and is conveyed to the air pre-cooling purification system after being discharged from the rectification cold box to be used as dry gas.

8. The argon recovery device for removing carbon monoxide and integrating high-purity nitrogen by rectification according to claim 7, further comprising:

the cooler is arranged on a pipeline between the carbon monoxide reaction furnace and the argon precooling and purifying system; used for cooling the high-temperature argon after the oxygen removal of the carbon monoxide reaction furnace.

9. The argon recovery device for removing carbon monoxide and integrating high-purity nitrogen through rectification according to claim 7, wherein the evaporation side of the argon column condensation evaporator is communicated with the outside of the rectification cold box through a pipeline so as to supplement liquid argon for the argon column condensation evaporator through the pipeline.

10. The argon recovery device for removing carbon monoxide and integrating high-purity nitrogen by rectification according to claim 7, further comprising:

the argon circulating compressor is arranged on a pipeline which sequentially passes through the argon tower condensation evaporator and the heat exchanger and sequentially passes through the heat exchanger and a second reboiler of the argon tower; and the circulating argon is used for pressurizing the circulating argon sent out of the rectifying cold box and then is sent back to the rectifying cold box.

Technical Field

The invention relates to an argon recovery method, in particular to an argon recovery method and an argon recovery device for removing carbon monoxide and integrating high-purity nitrogen by a rectification method.

Background

Czochralski method (Czochralski method) is the main method for producing single crystal silicon, and 70% to 80% of silicon single crystal worldwide is produced by the Czochralski method. The most common Czochralski process for producing single crystal silicon employs a reduced pressure crystal pulling process that is both a vacuum process and a flowing atmosphere process; the decompression process is characterized in that high-purity argon is continuously introduced into a hearth of a single crystal furnace at a constant speed in the silicon single crystal drawing process, and meanwhile, a vacuum pump continuously pumps the argon outwards from the hearth to keep the vacuum degree in the hearth to be stabilized at about 20 torr. The vacuum pump for the reduced pressure crystal pulling process generally adopts a slide valve pump, and the slide valve pump is a mechanical vacuum pump which uses oil to maintain sealing. The argon gas carries silicon oxide and impurity volatiles generated due to high temperature during the single crystal pulling process, and is discharged to the atmosphere by pumping of a vacuum pump.

Through the analysis of the discharged argon, the main impurity components are alkane such as oxygen, nitrogen, carbon monoxide, carbon dioxide, methane and the like, and liquid lubricating oil mist; the recycling of the argon has great practical significance.

Known techniques for argon recovery purification: carrying out coarse oil removal on argon recovered from a single crystal furnace, and then carrying out high-precision oil removal and dust removal after compression and cooling; then, hydrocarbons such as methane and the like and carbon monoxide react with oxygen to produce water and carbon dioxide through high-temperature catalysis, and the excess oxygen (the oxygen is added when the impurity oxygen is insufficient) is ensured in the catalytic reaction; after cooling, enabling excessive oxygen to react with added hydrogen under the action of a catalyst to generate water, and ensuring excessive reaction hydrogen, wherein impurity components in the argon after treatment are water, carbon dioxide, hydrogen and nitrogen; and finally, adsorbing water and carbon dioxide by an argon normal-temperature adsorption unit to obtain crude argon only containing nitrogen and hydrogen as impurities. The argon normal-temperature adsorption unit consists of two adsorbers, adsorbents for adsorbing water and carbon dioxide are filled in the adsorbers, one adsorber performs adsorption work, and the other adsorber performs regeneration work including pressure relief, heating and cold blowing. The gas for regeneration work uses nitrogen, the regenerated nitrogen comes from the production or outsourcing of the low-temperature rectifying tower in the cold box, and the argon normal-temperature adsorption unit automatically controls the operation switching through the time program controller.

In patent 201210078306.x, the low-temperature rectification part uses air for circulating refrigeration, so that the energy consumption is high, the flow is complex, the excessive hydrogen added is discharged, and the utilization rate is low; in patent 201410618341.5, air compression and double-tower flow are adopted, so that the energy consumption is not advantageous, the structure is complex, and the equipment investment is increased; in patent 201621146690.2, the amount of external liquid argon provided for keeping the cold box is large, and the extraction rate is low because of the limitation of regenerated gas, and the patent only designs a hydrogenation mode to remove oxygen, so that the danger is large; in patent CN 108645118A, the stability is poor due to the low-temperature moving part; in patent CN 109631495A, use positive current expansion flow, take low temperature moving part, stability is relatively poor, is applicable to the argon atmosphere and takes the pressure to go out the tower the condition, is not suitable for the argon.

Therefore, the technical personnel in the field are dedicated to develop an argon recovery method which has simpler process, no hydrogen deoxygenation process, carbon monoxide removal by using a rectification method, no low-temperature moving parts, more convenient operation and higher extraction rate.

Disclosure of Invention

The invention aims to provide an argon recovery method and device for removing carbon monoxide and integrating high-purity nitrogen by a rectification method aiming at the defects in the prior art.

In order to achieve the purpose, the invention adopts the technical scheme that:

provides an argon recovery method for removing carbon monoxide and integrating high-purity nitrogen by a rectification method, which comprises an argon recovery flow path and an air nitrogen flow path,

the argon gas recovery flow path comprises the following steps:

s11, pressurizing the recovered argon by an argon compressor, removing oil and dust, and then feeding the argon into a carbon monoxide reaction furnace to remove oxygen in the argon; cooling the argon after deoxygenation by a cooler, and then, introducing the argon into an argon precooling and purifying system to remove water and carbon dioxide in the argon to obtain dry crude argon;

s12, feeding the dry crude argon into a rectification cold box, cooling to a liquefaction temperature through a heat exchanger, entering a first reboiler of an argon column arranged at the bottom of the argon rectification column, liquefying gas in the first reboiler of the argon column, gasifying liquid out of the first reboiler of the argon column through a throttling and pressure reducing part, and feeding the gasified liquid into the upper middle part of the argon rectification column to participate in rectification;

s13, feeding the gas-liquid mixed fluid into the fine argon tower, wherein the liquid part descends along with the liquid in the tower, and pure liquid argon is obtained at the bottom of the tower; pure liquid argon is pumped out from the bottom of the refined argon tower, throttled and depressurized and then sent to the evaporation side of the condensation evaporator of the argon tower, the pure liquid argon is evaporated into argon gas on the evaporation side of the condensation evaporator of the argon tower, and the argon gas is sent out of a rectification cold box after being reheated by a heat exchanger to recover cold energy;

s14, feeding the gas-liquid mixed fluid into the fine argon column, wherein the gas part rises along with the gas in the column, the gas at the top of the column mainly comprises carbon monoxide and nitrogen, and one part of the gas extracted from the top of the fine argon column enters a condensation evaporator of the argon column and is condensed into liquid and then fed into the fine argon column;

the air nitrogen flow path comprises the following steps:

s21, after being compressed by an air compressor, the air enters an air precooling and purifying system to remove water and carbon dioxide in the air; the dried air is cooled to the liquefaction temperature through a heat exchanger in a rectification cold box, and then is sent to the bottom of a nitrogen tower to provide rectification gas for the nitrogen tower;

s22, liquid-carrying air entering the bottom of the nitrogen column, wherein heavy components are accumulated in the liquid, and liquid oxygen-enriched air is obtained at the bottom of the column; wherein light components are accumulated in the gas, and high-purity nitrogen is obtained at the top of the tower;

s23, dividing the high-purity nitrogen extracted from the top of the nitrogen tower into two parts: sending the first part of nitrogen to the high-temperature side of a condensation evaporator of the nitrogen tower, cooling the nitrogen to liquid nitrogen, sending the cooled nitrogen back to the nitrogen tower, and participating in rectification of the nitrogen tower; the second part of nitrogen is sent out of the rectification cold box after being reheated by a heat exchanger to recover cold energy, and then is sent into an argon precooling and purifying system to be used as regeneration gas;

s24, after the pressure of the oxygen-enriched liquid air extracted from the bottom of the nitrogen tower is adjusted, the oxygen-enriched liquid air enters a nitrogen tower condensation evaporator to provide a cold source for the nitrogen tower, is vaporized into oxygen-enriched gas, exits the nitrogen tower condensation evaporator, then enters a heat exchanger for reheating, exits a rectifying cold box and is conveyed to an air precooling and purifying system to serve as dry gas.

Further, in step S11, the argon gas after oxygen removal is cooled to 35 to 40 ℃ by a cooler, and then enters an argon gas precooling and purifying system, and is cooled to 5 to 8 ℃ by an argon gas precooling machine, and then enters an argon gas purifier to remove water and carbon dioxide, so as to obtain dry crude argon gas.

Further, in step S13, make-up liquid argon from the outside of the rectification cold box enters the evaporation side of the condensation evaporator of the argon refining column through a pipeline.

Further, in step S13, the argon gas sent out of the rectification cold box is divided into two parts: the first part of argon is used as argon product and can be pressurized or directly fed; and the second part of argon is taken as circulating gas, enters an argon circulating compressor for pressurization, is sent back to the rectifying cold box, is cooled by the heat exchanger, enters the argon tower second reboiler at the bottom of the fine argon tower, is liquefied therein, and is sent to the argon tower condensation evaporator for providing a cold source for the argon tower condensation evaporator after being depressurized.

Further, in step S14, the gas withdrawn from the top of the argon refining column is divided into two parts: the first part is sent out of the tower for emptying after being reheated by a heat exchanger to recover cold energy; and the second part of gas enters the gas side of the argon tower condensation evaporator to be condensed into liquid, flows into the argon refining tower and provides liquid for rectification.

Further, in step S23, the first part of the nitrogen gas is sent to the high temperature side of the nitrogen tower condensation evaporator, cooled to liquid nitrogen, and then sent back to the nitrogen tower to participate in rectification of the nitrogen tower, and the other part of the liquid nitrogen can be taken as a by-product and pumped out of the rectification cold box.

The argon recovery device comprises an argon compressor, a carbon monoxide reaction furnace, an argon precooling and purifying system, an air compressor, an air precooling and purifying system, a heat exchanger, a refined argon tower, a first argon tower reboiler, a second argon tower reboiler, an argon tower condensation evaporator, a nitrogen tower and a nitrogen tower condensation evaporator; wherein:

the argon compressor is connected with the argon precooling and purifying system through the carbon monoxide reaction furnace by a pipeline, the argon compressor is used for pressurizing the recovered argon, the pressurized recovered argon is subjected to oxygen removal by the carbon monoxide reaction furnace and then is sent into the argon precooling and purifying system to be cooled to remove water and carbon dioxide in the argon;

the argon precooling and purifying system is connected with a first reboiler of the argon tower arranged at the bottom of the argon rectifying tower through a pipeline and the heat exchanger so as to cool the dry argon to the liquefaction temperature through the heat exchanger and send the dry argon into the first reboiler of the argon tower to form a gas-liquid mixed fluid, and the bottom of the first reboiler of the argon tower is communicated with the middle upper part of the argon rectifying tower through a pipeline so as to send the gas-liquid mixed fluid in the reboiler of the argon tower into the middle upper part of the argon rectifying tower to participate in rectification after pressure regulation;

the bottom of the fine argon tower is communicated with the argon tower condensation evaporator through a pipeline so as to pump pure liquid argon at the bottom of the fine argon tower to the evaporation side of the argon tower condensation evaporator and evaporate the pure liquid argon into argon at the evaporation side; the evaporation side of the argon tower condensation evaporator is communicated with the outside of the rectification cold box through a pipeline and the heat exchanger, so that argon on the evaporation side is reheated by the heat exchanger and then is sent out of the rectification cold box;

the pipeline out of the rectifying cold box is divided into two branches, wherein one branch can be directly connected with an argon product end or connected with an argon product end after being pressurized, and the other branch is connected with a second reboiler of the argon tower through a heat exchanger; so as to divide the argon sent out of the rectification cold box into two parts: a first portion of argon is used as an argon product; a second part of argon is taken as circulating gas and sent back to the rectification cold box, the circulating gas is cooled by a heat exchanger and then enters a second reboiler of the argon tower at the bottom of the fine argon tower, the argon is liquefied in the reboiler, and the argon is sent into a condensation evaporator of the argon tower after pressure reduction to provide a cold source for the argon tower;

the top of the argon refining tower is communicated with the argon precooling and purifying system through a heat exchanger rectification cold box and is communicated with the gas side of the argon tower condensation evaporator through a pipeline;

the gas withdrawn from the top of the fine argon column was divided into two parts: the first part is sent out of the tower for emptying after being reheated by a heat exchanger to recover cold energy; the second part of gas enters the gas side of the argon tower condensation evaporator to be condensed into liquid, flows into the argon refining tower and provides liquid for rectification;

the air compressor is connected with the air pre-cooling purification system through a pipeline, and air is pressurized by the air compressor and then sent into the air pre-cooling purification system so as to remove water and carbon dioxide in the air after being cooled;

the air pre-cooling purification system is communicated with the bottom of the nitrogen tower through a heat exchanger through a pipeline, so that dried air is cooled to a liquefaction temperature through the heat exchanger and then is sent to the bottom of the nitrogen tower, and rectification gas is provided for the nitrogen tower;

the top of the nitrogen tower is communicated with the argon pre-cooling and purifying system through a heat exchanger outlet rectification cold box and communicated with the high-temperature side of the nitrogen tower condensation evaporator through a pipeline; the gas extracted from the top of the nitrogen tower is divided into two parts, the first part is sent to the high-temperature side of the condensation evaporator of the nitrogen tower, after being cooled to liquid nitrogen, one part of the liquid nitrogen is sent to the top of the nitrogen tower through a pipeline to participate in rectification, and the other part of the liquid nitrogen is sent out of a rectification cold box through a pipeline; the second part is reheated by the heat exchanger and then is discharged from a rectification cold box and sent to the argon precooling and purifying system to be used as regeneration gas; and

the bottom of the nitrogen tower is communicated with the top of the nitrogen tower condensation evaporator through a pipeline; and the oxygen-enriched liquid air extracted from the bottom of the nitrogen tower enters the nitrogen tower condensation evaporator to provide a cold source for the nitrogen tower condensation evaporator after being subjected to pressure regulation, is vaporized into oxygen-enriched air, then enters the heat exchanger for reheating, and is conveyed to the air pre-cooling purification system after being discharged from the rectification cold box to be used as dry gas.

Further, still include:

the cooler is arranged on a pipeline between the carbon monoxide reaction furnace and the argon precooling and purifying system; used for cooling the high-temperature argon after the oxygen removal of the carbon monoxide reaction furnace.

Further, the evaporation side of the argon tower condensation evaporator is communicated with the outside of the rectification cold box through a pipeline so as to supplement liquid argon for the argon tower condensation evaporator through the pipeline.

Further, still include:

the argon circulating compressor is arranged on a pipeline which sequentially passes through the argon tower condensation evaporator and the heat exchanger and sequentially passes through the heat exchanger and a second reboiler of the argon tower; and the circulating argon is used for pressurizing the circulating argon sent out of the rectifying cold box and then is sent back to the rectifying cold box.

By adopting the technical scheme, compared with the prior art, the invention has the following technical effects:

the invention provides convenience for liquid argon in the recycling field, and the liquid argon is used for providing cold energy; the carbon monoxide gas generated in the crystal pulling process is used for removing the mixed oxygen, and the nitrogen and the excessive carbon monoxide are removed by using a low-temperature rectification method, so that the recovery rate of argon is improved, the flow and operation of low-temperature rectification are simplified, and the operation energy consumption is reduced; by utilizing an integrated air nitrogen flow path and utilizing the rich cold energy of liquid argon, the nitrogen produced in the cold box can reduce the limitation of regenerated gas and improve the extraction rate of recovered argon; and partial liquid nitrogen is produced by utilizing the cold energy of the abundant liquid argon, so that the economic benefit is improved.

Drawings

FIG. 1 is a schematic flow diagram of an argon recovery unit for carbon monoxide removal and integration of high purity nitrogen by rectification in accordance with the present invention;

wherein the reference numerals are:

an argon compressor 1; a carbon monoxide reaction furnace 2; a cooler 3; an argon pre-cooling purification system 4; a rectification cold box 5; a heat exchanger 6; a fine argon column 7; an argon column first reboiler 8; argon column second reboiler 9; an argon column condenser-evaporator 10; a nitrogen column 11; a nitrogen column condenser evaporator 12; an air compressor 13; an air pre-cooling purification system 14; an argon gas circulation compressor 15; v1 pure liquid argon throttle valve; v2 crude liquid argon throttle valve; v5 recycle liquid argon throttle.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The invention is further described with reference to the following drawings and specific examples, which are not intended to be limiting.