High-purity nitrogen and ultra-pure nitrogen preparation device

Abstract

The utility model discloses a device for preparing high-purity nitrogen and ultra-pure nitrogen. The device comprises a lower tower, an upper tower, a main condensation evaporator, a subcooler, a main heat exchanger, a turbine expansion unit and an ultra-pure nitrogen tower, a raw material air outlet and an expanded air outlet are formed in the main heat exchanger, gas flowing out of the raw material air outlet is communicated with the bottom of the lower tower through a pipeline, and gas flowing out of the expanded air outlet is sequentially connected with the turbine expansion unit and the upper tower through pipelines; a second lower tower liquid nitrogen outlet in the middle of the lower tower is communicated with the ultra-pure nitrogen tower through a pipeline; an ultra-pure nitrogen product pipeline is arranged at the upper part of the ultra-pure nitrogen tower; and ultra-pure nitrogen or ultra-pure liquid nitrogen is discharged from the ultra-pure nitrogen product pipeline. The nitrogen and the liquid nitrogen in the lower tower are used as heat exchange media for rectifying the nitrogen by the ultra-pure nitrogen tower, so that the rectifying effect of the ultra-pure nitrogen tower is improved, the operation pressure of the ultra-pure nitrogen tower is reduced, more purified air enters the lower tower to participate in rectification, and the extraction rate of ultra-pure nitrogen and high-purity nitrogen is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to air separation preparation technical field, concretely relates to high -purity nitrogen, super -pure nitrogen preparation device. BACKGROUND

[0002] With the rapid development of metallurgy, petrochemical, coal chemical industry, electronics and other industries, in the application field of air separation, the multi-purpose of nitrogen makes the demand of nitrogen in some industrial fields much higher than that of oxygen.

[0003] Nitrogen is a kind of chemically inert gas, which is not easy to react with other substances chemically. Therefore, as an important raw material, nitrogen is widely used in chemical industry, electronics, metallurgy, food, machinery and other fields. Nitrogen is divided into pure nitrogen, high-purity nitrogen and super-pure nitrogen according to the purity, and the purity requirements of nitrogen are different in different fields. With the development of semiconductor and integrated circuit fields in China, the purity requirement of nitrogen is higher and higher, and the demand for high-purity nitrogen and super-pure nitrogen is increasing.

[0004] Therefore, it is necessary to provide a high-purity nitrogen and super-pure nitrogen preparation device that can improve the extraction rate of super-pure nitrogen and high-purity nitrogen to meet the increasing demand of the existing market. UTILITY MODEL CONTENT

[0005] The utility model aims at providing high-purity nitrogen and super-pure nitrogen preparation device to solve the problem that the extraction rate of high-purity nitrogen and super-pure nitrogen of the existing preparation device cannot meet the demand of high-purity nitrogen and super-pure nitrogen in the market.

[0006] In order to achieve the above-mentioned purpose, the utility model provides high-purity nitrogen and super-pure nitrogen preparation device, including lower tower, upper tower, main condensation evaporator, supercooler, main heat exchanger, turbine expansion unit and super-pure nitrogen tower;The main heat exchanger is provided with raw material air outlet and expanded air outlet, the gas flowing out through the raw material air outlet is connected with the bottom of the lower tower through pipeline, and the gas flowing out through the expanded air outlet is connected with the turbine expansion unit and the upper tower through pipeline in sequence;The lower tower, the main condensation evaporator and the upper tower are stacked from bottom to top, and the main condensation evaporator is communicated with the upper tower;The bottom of the lower tower is provided with liquid air outlet, and the top and middle parts of the lower tower are respectively provided with first lower tower liquid nitrogen outlet and second lower tower liquid nitrogen outlet, and the liquid air outlet of the lower tower and the first lower tower liquid nitrogen outlet of the top are respectively transported to the middle and top of the upper tower through pipeline after passing through the supercooler;The second lower tower liquid nitrogen outlet in the middle of the lower tower is communicated with the super-pure nitrogen tower through pipeline;The upper part of the super-pure nitrogen tower is provided with super-pure nitrogen product pipeline, and the super-pure nitrogen product pipeline discharges super-pure nitrogen or super-pure liquid nitrogen.

[0007] Optionally, the main condensation evaporator is communicated with the top end of the lower tower and the bottom end of the upper tower.

[0008] Optionally, the ultra-pure nitrogen tower bottom is provided with an ultra-pure nitrogen tower evaporator, an air inlet end of the ultra-pure nitrogen tower evaporator is connected with the lower tower top end through a pipeline, and the pipeline is connected with the pipeline of the main condenser evaporator; and an outlet end of the ultra-pure nitrogen tower evaporator is connected with the upper tower top through a pipeline.

[0009] Optionally, the upper tower top of the ultra-pure nitrogen tower is provided with an ultra-pure nitrogen tower condenser for providing reflux liquid for the ultra-pure nitrogen tower.

[0010] Optionally, the main heat exchanger is provided with a raw material air inlet and a pressurized air inlet, the raw material air inlet is provided with an air inlet pipe, and the pressurized air inlet is provided with a pressurized air inlet pipe connected with the turboexpander set.

[0011] Optionally, the pressurized air inlet pipe is connected with the air inlet pipe through a pressurized end of the turboexpander set.

[0012] Optionally, the turboexpander set is composed of two turboexpanders with the same structure; the pressurized air inlet pipe is provided with a pressurized branch pipe connected with the two turboexpanders.

[0013] Optionally, the upper tower top is provided with a high-purity nitrogen gas outlet connected with the subcooler and the main heat exchanger through pipelines and then discharged.

[0014] Optionally, the ultra-pure nitrogen product pipeline includes an ultra-pure liquid nitrogen pipe and an ultra-pure nitrogen gas pipe, and the ultra-pure nitrogen gas pipe is collected through the main heat exchanger.

[0015] Optionally, the upper tower top is provided with an upper tower liquid nitrogen outlet connected with the ultra-pure nitrogen tower condenser through a pipeline, and a liquid nitrogen vapor outlet of the ultra-pure nitrogen tower condenser is connected with the upper tower top through a pipeline.

[0016] Compared with the prior art, the high-purity nitrogen gas and ultra-pure nitrogen gas preparation device has the following beneficial effects:

[0017] The high-purity nitrogen gas and ultra-pure nitrogen gas preparation device uses the nitrogen gas and liquid nitrogen of the lower tower as the heat exchange medium for rectifying the nitrogen gas in the ultra-pure nitrogen tower, improves the rectification effect of the ultra-pure nitrogen tower, reduces the operating pressure of the ultra-pure nitrogen tower, and more purified air enters the lower tower to participate in rectification, thereby improving the extraction rate of the ultra-pure nitrogen and high-purity nitrogen. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0019] Identified in the figure: 1, lower tower; 11, liquid air outlet; 12, first lower tower liquid nitrogen outlet; 13, second lower tower liquid nitrogen outlet; 2, upper tower; 21, high-purity nitrogen gas outlet; 22, upper tower liquid nitrogen outlet; 3, main condensation evaporator; 4, subcooler; 5, main heat exchanger; 51, raw material air outlet; 52, expanded air outlet; 53, raw material air inlet; 531, air inlet pipe; 54, pressurized air inlet; 541, pressurized air inlet pipe; 542, pressurized branch pipe; 6, ultra-pure nitrogen tower; 61, ultra-pure nitrogen product pipeline; 611, ultra-pure liquid nitrogen pipe; 612, ultra-pure nitrogen pipe; 62, ultra-pure nitrogen tower evaporator; 63, ultra-pure nitrogen tower condenser; 7, turbine expander. DETAILED DESCRIPTION

[0020] The following will be described in detail in combination with the drawings and specific embodiments. In the following description, many specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in many different ways other than those described herein, and one skilled in the art can make similar modifications without departing from the spirit of the present application, so the present application is not limited to the specific embodiments disclosed below.

[0021] The high-purity nitrogen gas and ultra-pure nitrogen gas production device of the present application can be applied to occasions for producing high-purity nitrogen gas and ultra-pure nitrogen gas, and of course can also be used for other similar application scenarios. The high-purity nitrogen gas and ultra-pure nitrogen gas production device will be described in detail below.

[0022] Referring to the drawings Figure 1 As shown in the drawings, a structure schematic diagram of a preferred embodiment of the high-purity nitrogen gas and ultra-pure nitrogen gas production device of the present application is shown. The high-purity nitrogen gas and ultra-pure nitrogen gas production device comprises a main heat exchanger 5, a lower tower 1, a main condensation evaporator 3 and an upper tower 2 stacked from bottom to top, wherein the main condensation evaporator 3 and the upper tower 2 are in communication, the bottom of the lower tower 1 is provided with a liquid air outlet 11, the top and middle part of the lower tower 1 are respectively provided with a first lower tower liquid nitrogen outlet 12 and a second lower tower liquid nitrogen outlet 13, the liquid air outlet 11 of the lower tower 1 and the first lower tower liquid nitrogen outlet 12 at the top of the lower tower 1 are respectively conveyed to the middle and top of the upper tower 2 through a pipeline after passing through a subcooler 4, the second lower tower liquid nitrogen outlet 13 in the middle of the lower tower 1 is connected to an ultra-pure nitrogen tower 6 through a pipeline, and the upper part of the ultra-pure nitrogen tower 6 is provided with an ultra-pure nitrogen product pipeline 61; the main heat exchanger 5 is provided with a raw material air outlet 51 and an expanded air outlet 52, the gas flowing out through the raw material air outlet 51 is connected to the bottom of the lower tower 1 through a pipeline, and the gas flowing out through the expanded air outlet 52 is connected to a turbine expander set and the upper tower 2 in sequence through a pipeline.

[0023] The utility model discloses a liquid air export 11 setting is used for conveying the liquid air of lower tower 1 bottom after supercooler 4 to the middle part of upper tower 2, provides the cold source for supercooler 4 simultaneously, optimizes the rectification condition of upper tower 2, improves the rectification effect of upper tower 2, through the setting of first lower tower liquid nitrogen export 12 of lower tower 1 top, is used for conveying the liquid nitrogen of lower tower 1 top after supercooler 4 to the top of upper tower 2, provides the cold source for supercooler 4 simultaneously, provides rectification reflux liquid for the top of upper tower, through the second lower tower liquid nitrogen export 13 of lower tower 1 middle part, the liquid nitrogen of lower purity is transported to the further rectification purification of ultrapure nitrogen tower 6, forms ultrapure liquid nitrogen product, through the setting of ultrapure nitrogen product pipeline 61, is used for guiding ultrapure liquid nitrogen, directly leads out to obtain ultrapure liquid nitrogen product, part ultrapure liquid nitrogen is formed ultrapure nitrogen gas product through the heat exchange of main heat exchanger 5.

[0024] Refer to the accompanying Figure 1 As shown in the utility model, the top of the main condenser evaporator 3 is communicated with the lower tower 1, and the bottom of the upper tower 2 is communicated with the main condenser evaporator 3. The main condenser evaporator 3 is used for providing reflux liquid for the lower tower 1 and providing bottom rising steam for the upper tower 2 and separating non-condensable gas in the steam at the top of the lower tower 1.

[0025] Refer to the accompanying Figure 1 As shown in the utility model, the bottom of the ultrapure nitrogen tower 6 is provided with an ultrapure nitrogen tower evaporator 62. The gas inlet end of the ultrapure nitrogen tower evaporator 62 is communicated with the top of the lower tower 1 through a pipeline and is connected with the pipeline of the main condenser evaporator 3. The outlet end of the ultrapure nitrogen tower evaporator 62 is communicated with the top of the upper tower 2 through a pipeline.

[0026] The utility model discloses the setting of the ultrapure nitrogen tower evaporator 62 is used for heat exchange of liquid nitrogen and nitrogen gas, so that the liquid nitrogen can be rectified again, thereby improving the purity of the liquid nitrogen.

[0027] Refer to the accompanying Figure 1 As shown in the utility model, the top of the ultrapure nitrogen tower 6 is provided with an ultrapure nitrogen tower condenser 63 for providing reflux liquid for the ultrapure nitrogen tower 6. The liquid nitrogen is refluxed multiple times, so that the liquid nitrogen can be rectified and purified multiple times, thereby improving the purity of the liquid nitrogen or nitrogen gas product obtained subsequently.

[0028] Refer to the accompanying Figure 1 As shown in the utility model, the main heat exchanger 5 is provided with a raw material air inlet 53 and a pressurized air inlet 54. The raw material air inlet 53 is provided with an air inlet pipe 531. The pressurized air inlet 54 is provided with a pressurized air inlet pipe 541, which is connected with the turbine expander set.

[0029] The utility model discloses a primary rectification separation is used for the air after precooling and purification through the main heat exchanger 5 enters the lower tower 1, and the air after the turbine expander set is directly entered into the upper tower 2 can further supplement the cold of the upper tower 2, improve the nitrogen purity.

[0030] Referring to the accompanying Figure 1 As shown in the utility model discloses a pressurization branch pipe 542 and pressurization inlet pipe 541 are connected with two turbine expanders 7 respectively on the pressurization inlet pipe 541, and the pressurization branch pipe 542 is equipped with two turbine expanders 7.

[0031] The utility model discloses the setting of pressurization branch pipe 542, cooperate pressurization inlet pipe 541, make two turbine expanders 7 can carry out alternate use, can reduce the running time of single equipment, thereby reduce the abrasion of equipment, prolong the life of equipment, need special explanation, the connecting point of pressurization branch pipe 542 gas outlet end and pressurization inlet pipe 541 is located the rear end of another turbine expander 7, avoid appearing multiple expansion, turbine expander 7 carries out protection.

[0032] Referring to the accompanying Figure 1 As shown in the utility model discloses the top of upper tower 2 is equipped with high purity nitrogen gas outlet 21, and the high purity nitrogen gas outlet 21 is discharged after passing through supercooler 4 and main heat exchanger 5 in proper order through pipeline. The utility model discloses the setting of high purity nitrogen gas outlet 21 is used for the high purity nitrogen gas of upper tower 2 top to export, makes the temperature of the nitrogen gas that the exported high purity nitrogen gas passes through the heat exchange of supercooler 4 and main heat exchanger 5, and the temperature of the nitrogen gas rises, is convenient for the collection of high purity nitrogen gas at normal temperature.

[0033] Referring to the accompanying Figure 1 As shown in the utility model discloses that superpure nitrogen product pipeline 61 includes superpure liquid nitrogen pipe 611 and superpure nitrogen gas pipe 612, and the superpure nitrogen gas pipe 612 is collected after passing through main heat exchanger 5. The utility model discloses the setting of superpure liquid nitrogen pipe 611 can export and collect the superpure liquid nitrogen of superpure nitrogen tower 6 upper portion, and the setting of superpure nitrogen gas pipe 612 makes the part liquid nitrogen that exports passes through the heat exchange of main heat exchanger 5, provides the cold source for main heat exchanger 5 simultaneously, and it is convenient for the collection and storage of subsequent superpure nitrogen gas.

[0034] Referring to the accompanying Figure 1As shown, the upper tower 2 is provided with a nitrogen-rich waste gas pipe in the upper middle part, which passes through the supercooler 4 and the main heat exchanger 5 in sequence through the pipeline; the top of the upper tower 2 is provided with an upper tower liquid nitrogen outlet 22, which is connected to the ultra-pure nitrogen tower condenser 63 through the pipeline, and the liquid nitrogen vapor outlet of the ultra-pure nitrogen tower condenser 63 is connected to the top of the upper tower 2 through the pipeline.

[0035] The nitrogen-rich waste gas in the upper middle part of the upper tower 2 is discharged through the setting of the nitrogen-rich waste gas pipe, and the nitrogen-rich waste gas passes through the supercooler 4 and the main heat exchanger 5 to provide cold heat for heat exchange; the setting of the upper tower liquid nitrogen outlet 22 is used to guide the liquid nitrogen formed at the top of the upper tower 2 to provide a cold source for the ultra-pure nitrogen tower condenser 63, and the liquid nitrogen after heat exchange is transported to the top of the upper tower 2.

[0036] Refer to the accompanying Figure 1 As shown, the preparation process of the utility model is as follows:

[0037] Firstly, the air after pre-cooling and purification is divided into two streams, enters the cold box, and is cooled and heated in the main heat exchanger 5 in the cold box, and is cooled to near liquefaction temperature, and is transported into the bottom of the lower tower 1 to carry out rectification, and the other air enters the main heat exchanger 5 after passing through the pressurizing end of the turbine expander 7, then passes through the expansion end of the turbine expander 7, and then is transported into the middle part of the upper tower 3; in the lower tower 1, the ascending gas and the reflux liquid are in full contact, and after continuous heat exchange, the nitrogen concentration of the ascending gas is continuously increased, and the oxygen concentration of the reflux liquid is continuously increased, and finally the nitrogen gas is obtained at the top of the lower tower 1, and the oxygen-rich liquid air is obtained at the bottom of the lower tower 2;

[0038] Then, the nitrogen gas at the top of the lower tower 1 enters the main condensing evaporator 3 through the pipeline and is condensed into high-purity liquid nitrogen, and at the same time when the nitrogen gas is condensed, part of the liquid oxygen in the main condensing evaporator 3 is vaporized, part of the high-purity liquid nitrogen after condensation is used as the reflux liquid of the lower tower 1 to participate in the rectification of the lower tower 1, and the rest of the high-purity liquid nitrogen passes through the supercooling of the supercooler 4 and then throttles through the throttle valve, part of the high-purity liquid nitrogen product after throttling is extracted for storage, and the rest is sent to the upper tower 2 to continue to participate in rectification; and a small part of the nitrogen gas at the top of the lower tower 1 enters the ultra-pure nitrogen gas evaporator 62 as a heat source, exchanges heat with the liquid nitrogen at the bottom of the ultra-pure nitrogen tower 6, and the small part of the nitrogen gas is condensed into liquid nitrogen and flows into the upper tower 2 after throttling through the throttle valve;

[0039] And in the upper tower 2, after the rectification of the upper tower 2, the liquid oxygen and oxygen gas at the bottom of the upper tower 2 can be extracted as products through the pipeline; the nitrogen gas at the top of the upper tower 2 is extracted through the pipeline, reheated in sequence through the supercooler 4 and the main heat exchanger 5, and then extracted as high-purity nitrogen gas product; in addition, the dirty nitrogen gas formed in the upper part of the upper tower 2 is discharged or used as a regenerative gas source for the purification system after being heated through the supercooler 4 and the main heat exchanger 5;

[0040] In addition, a small amount of liquid nitrogen is extracted from the middle of the lower tower 1 and is transported into the bottom of the ultra-pure nitrogen tower 6 through a pipeline, and since the bottom of the ultra-pure nitrogen tower 6 is provided with an ultra-pure nitrogen evaporator 62, the small amount of nitrogen gas extracted from the lower tower 1 is used as a heat source to make the liquid nitrogen flowing downward in the bottom of the ultra-pure nitrogen tower 6 partially evaporate, at the same time, the small amount of nitrogen gas extracted from the lower tower 1 is liquefied to form liquid nitrogen, and the liquid nitrogen is throttled and sent into the upper tower 2, and a part of the liquid nitrogen in the bottom of the ultra-pure nitrogen evaporator 62 is throttled and transported to the upper tower 2; the ultra-pure nitrogen tower 6 passes through the ultra-pure nitrogen condenser 63 at the top, and the nitrogen gas in the top of the lower tower 1 is liquefied in the main condenser evaporator 3 and is then throttled and transported to the low-pressure liquid nitrogen at the top end of the upper tower 2 as a cold source, so that a part of the ascending gas in the ultra-pure nitrogen tower 6 is condensed as reflux liquid of the ultra-pure nitrogen tower 6, and the other part of the ultra-pure nitrogen is sent out of the cold box as a product; specifically, a part of the ultra-pure liquid nitrogen is directly sent out of the cold box as an ultra-pure liquid nitrogen product through the ultra-pure liquid nitrogen pipe 611, and the other part of the ultra-pure liquid nitrogen is sent out of the cold box as an ultra-pure nitrogen gas product through the ultra-pure nitrogen gas pipe 612 after passing through the main heat exchanger 5.

[0041] The nitrogen gas and the liquid nitrogen of the lower tower 1 are used as heat exchange mediums of the ultra-pure nitrogen evaporator 62 and the ultra-pure nitrogen condenser 63, so that the operation pressure of the ultra-pure nitrogen tower 6 is reduced, and more purified air enters the lower tower 1 to participate in rectification, and the extraction rate of the ultra-pure nitrogen and the high-purity nitrogen is improved.

[0042] The above embodiments are used to illustrate the application, and are not used to limit the application, and any scheme obtained by simple transformation of the application belongs to the protection scope of the application.

Claims

1. A device for producing high-purity nitrogen and ultrapure nitrogen, characterized in that, The lower tower, the upper tower, the main condensing evaporator, the supercooler, the main heat exchanger, the turbine expander set and the ultra-pure nitrogen tower are included. The main heat exchanger is provided with a raw material air outlet and an expanded air outlet. The lower tower, the main condensing evaporator and the upper tower are stacked from bottom to top, and the main condensing evaporator and the upper tower are communicated. The bottom of the lower tower is provided with a liquid air outlet, and the top and middle part of the lower tower are respectively provided with a first lower tower liquid nitrogen outlet and a second lower tower liquid nitrogen outlet.

2. The device for preparing high-purity nitrogen or ultra-pure nitrogen according to claim 1, characterized in that, The upper part of the ultra-pure nitrogen tower is provided with an ultra-pure nitrogen product pipeline.

3. The device for preparing high-purity nitrogen or ultra-purity nitrogen according to claim 1, characterized in that, The main condensing evaporator is communicated with the top end of the lower tower and the bottom end of the upper tower.

4. The device for preparing high-purity nitrogen or ultra-purity nitrogen according to claim 1 or 3, characterized in that, The bottom of the ultra-pure nitrogen tower is provided with an ultra-pure nitrogen tower evaporator.

5. The device for preparing high-purity nitrogen and ultra-purity nitrogen according to claim 1, characterized in that, The top of the ultra-pure nitrogen tower is provided with an ultra-pure nitrogen tower condenser for providing reflux liquid for the ultra-pure nitrogen tower.

6. The device for preparing high-purity nitrogen or ultra-purity nitrogen according to claim 5, characterized in that, The main heat exchanger is provided with a raw material air inlet and a pressurized air inlet.

7. The device for preparing high-purity nitrogen or ultra-purity nitrogen according to claim 5 or 6, characterized in that, The pressurized air inlet is provided with a pressurized air inlet pipe connected with the turbine expander set. The turbine expander set is composed of two turbine expanders with the same structure.

8. The device for preparing high-purity nitrogen or ultra-purity nitrogen according to claim 1, characterized in that, The pressurized air inlet pipe is provided with a pressurized branch pipe connected with the two turbine expanders.

9. The device for preparing high-purity nitrogen or ultra-purity nitrogen according to claim 1, characterized in that, The top of the upper tower is provided with a high-purity nitrogen gas outlet.

10. The device for preparing high-purity nitrogen or ultra-purity nitrogen according to claim 4, characterized in that, The ultra-pure nitrogen product pipeline includes an ultra-pure liquid nitrogen pipe and an ultra-pure nitrogen gas pipe. The middle and upper part of the upper tower is provided with a nitrogen-rich waste gas pipe. The top of the upper tower is provided with an upper tower liquid nitrogen outlet connected with the ultra-pure nitrogen tower condenser. The liquid nitrogen vapor outlet of the ultra-pure nitrogen tower condenser is connected with the top of the upper tower through a pipeline.

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