Novel nitrogen making device

Abstract

The utility model discloses a novel nitrogen making device which comprises an air compressor, a pre-cooling unit, a purification system and a fractionating tower which are communicated in sequence, raw material air is compressed by the air compressor, cooled by the precooling unit and then enters the purification system; entering a fractionating tower; in a main heat exchanger of the fractionating tower, air exchanges heat with the refluxed oxygen-enriched gas and nitrogen, the temperature is reduced to be close to an air liquefaction point, the air enters a rectifying tower for rectification, and high-purity nitrogen is obtained at the top of the rectifying tower; one part of the high-purity nitrogen serves as product nitrogen, is reheated by the main heat exchanger, is discharged from the fractionating tower and is sent to a user; one part of the obtained liquid nitrogen is output as a product, and the other part of the obtained liquid nitrogen enters the rectifying tower again to serve as reflux liquid; one part of liquid air is throttled, enters the subcooler, is vaporized and then is converged with the expanded oxygen-enriched gas; the rectified liquid nitrogen enters a main heat exchanger through a liquid nitrogen pump to be reheated and serves as another stream of product nitrogen; the device can be used for producing nitrogen with two different pressures.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the improvement related technical field of nitrogen making device, and specifically relates to a novel nitrogen making device which can produce nitrogen gas with two different pressures, has small floor area and low cost. BACKGROUND

[0002] The existing nitrogen making device commonly has single-tower backflow waste gas expansion nitrogen making device; it can only output one kind of nitrogen gas product; another kind of double-tower pump nitrogen making device can only output nitrogen gas with lower pressure than that of the compressor; some users in the market need nitrogen gas with two different pressures under some special working conditions, and if the above-mentioned nitrogen making device is used to separately transport one kind of nitrogen gas, a large site is needed, and it is not economical at the same time.

[0003] Therefore, the utility model discloses a novel nitrogen making device which can produce nitrogen gas with two different pressures, has small floor area and low cost. SUMMARY

[0004] The utility model discloses a novel nitrogen making device which can produce nitrogen gas with two different pressures, has small floor area and low cost.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical scheme:

[0006] A novel nitrogen making device, comprising air compressor, pre-cooling unit, purification system and fractionating column which are sequentially communicated; raw material air is compressed by the air compressor, then cooled by the pre-cooling unit, and then enters the purification system; after water, carbon dioxide and hydrocarbon in the raw material air are adsorbed by the purification system, the raw material air enters the fractionating column; in the main heat exchanger of the fractionating column, the air exchanges heat with backflow oxygen-rich gas and nitrogen gas, the temperature is reduced to close to the air liquefaction point, and then the air enters the rectifying column to be rectified, and high-purity nitrogen gas is obtained at the top of the rectifying column; part of the high-purity nitrogen gas is used as product nitrogen gas, reheated by the main heat exchanger, and then output from the fractionating column and sent to the user; another part of the high-purity nitrogen gas is condensed and liquefied by the main cooler, part of the obtained liquid nitrogen is output as product, and another part of the liquid nitrogen reenters the rectifying column as backflow liquid; oxygen-rich liquid air extracted from the bottom of the rectifying column is supercooled by the cooler, then throttled in the main heat exchanger to evaporate, part of the oxygen-rich liquid air enters the supercooler, then enters the main heat exchanger to be reheated, and then enters the expander to be cooled; the oxygen-rich gas after expansion is reheated by the main heat exchanger, then output from the fractionating column, and used as regeneration gas and cold-blowing gas of the purification system; part of the liquid air is throttled to enter the supercooler to be vaporized, and then combined with the oxygen-rich gas after expansion; the rectified liquid nitrogen is reheated by the liquid nitrogen pump to enter the main heat exchanger, and used as another product nitrogen gas.

[0007] Preferably, the main heat exchanger in the fractionating column comprises two groups of first main heat exchanger and second main heat exchanger which are connected in series.

[0008] Compared with the prior art, the present invention provides a novel nitrogen generation device, which has the following beneficial effects:

[0009] The novel nitrogen generator described in this invention can produce two different pressures of nitrogen without adding a compressor. It has a small footprint and low cost, and can meet the different needs of users. Attached Figure Description

[0010] Figure 1 This is a schematic diagram illustrating the working principle of a novel nitrogen generator according to this utility model.

[0011] In the diagram: 1. Air compressor; 2. Precooling unit; 3. Purification system; 4. Distillation tower; E501. First main heat exchanger; E502. Second main heat exchanger. Detailed Implementation

[0012] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0013] like Figure 1 As shown, this utility model provides a novel nitrogen generation device, comprising an air compressor 1, a precooling unit 2, a purification system 3, and a fractionation tower 4 connected in sequence. The raw material air is compressed by the air compressor 1, cooled by the precooling unit 2, and then enters the purification system 3. After the purification system 3 adsorbs moisture, carbon dioxide, and hydrocarbons from the raw material air, it enters the fractionation tower 4. In the main heat exchanger (not shown) of the fractionation tower 4, the air exchanges heat with the refluxed oxygen-rich and nitrogen-rich air, lowering the temperature to near the air liquefaction point before entering the rectification tower (not shown) for rectification. High-purity nitrogen is obtained at the top of the rectification tower. A portion of the high-purity nitrogen is used as product nitrogen, which is reheated by the main heat exchanger and then exits the product. The fractionation column delivers the liquid nitrogen to the user; another portion is condensed and liquefied in the main cooler (not labeled), with part of the resulting liquid nitrogen being output as product and the other part being returned to the distillation column as reflux liquid; the oxygen-enriched liquid air drawn from the bottom of the distillation column is subcooled by the cooler (not labeled) and then throttled in the main heat exchanger to evaporate, part of which enters the subcooler (not labeled), then enters the main heat exchanger for reheating and enters the expander (not labeled) for cooling, the expanded oxygen-enriched gas is reheated in the main heat exchanger and exits the fractionation column 4 to the purification system 3 as regeneration gas and cold blowing gas for the purification system 3; a portion of the liquid air is throttled and enters the subcooler for vaporization and then merges with the expanded oxygen-enriched gas; the distilled liquid nitrogen is pumped by the liquid nitrogen pump (not labeled) into the main heat exchanger for reheating and becomes another product nitrogen gas.

[0014] In the embodiment, the main heat exchanger in the fractionating column comprises two groups of first main heat exchanger E501 and second main heat exchanger E502 connected in series.

[0015] In operation, the raw air is compressed by an air compressor (AC101) to a pressure below 0.85 MPa, cooled by a pre-cooling unit (Ru201), and then enters the purification system (MS301); after the water, carbon dioxide and hydrocarbons in the raw air are adsorbed in the purification system (MS301), the air enters the fractionating column; in the first main heat exchanger E501 / first main heat exchanger E502 of the fractionating column, the air exchanges heat with the returned oxygen-rich gas and nitrogen gas, the temperature is reduced to near the air liquefaction point, and the air enters the rectifying column (C501) for rectification, and high-purity nitrogen gas is obtained at the top of the rectifying column; part of the high-purity nitrogen gas is used as product nitrogen gas, reheated by the first main heat exchanger E501 / first main heat exchanger E502, and then discharged from the fractionating column and sent to the user; the other part is condensed and liquefied by the main cooler (K501), part of the obtained liquid nitrogen is output as product, and the other part reenters the rectifying column (C501) as reflux liquid; the oxygen-rich liquid air extracted from the bottom of the rectifying column (C501) is supercooled by the cold trap (E503), throttled in the second main heat exchanger E502, and evaporated, part of which enters the supercooler (E503), and then enters the first main heat exchanger E501 / first main heat exchanger E502 for reheating, and then enters the expander (ET501 / ET502) for refrigeration, the expanded oxygen-rich gas is reheated by the first main heat exchanger E501 / first main heat exchanger E502, and then discharged from the fractionating column and sent to the purification system (MS301) as the regeneration gas and cold blowing gas of the purification system (MS301); part of the liquid air is throttled and enters the supercooler (E503) to be vaporized and combined with the expanded oxygen-rich gas; the rectified liquid nitrogen is reheated by the liquid nitrogen pump (P501) in the first main heat exchanger E501 / first main heat exchanger E502, and used as another product nitrogen gas.

[0016] Compared with the prior art, the utility model has the advantages of the following:

[0017] The novel nitrogen making device increases the liquid nitrogen pump and the liquid nitrogen pump protection device; because the liquid nitrogen pump inlet pressure is limited, if the pressure exceeds, the liquid nitrogen pump will leak, in order to protect the normal operation of the liquid nitrogen pump, the liquid nitrogen pump throttle valve is increased; in order to prevent the liquid nitrogen pump cavitation, the liquid nitrogen passes through the supercooler (E503) and the pipeline separator, the nitrogen airproof valve, the liquid level meter and the pressure transmitter; the liquid nitrogen pump shaft purge gas is also increased; the utility model can produce two different pressure nitrogen gases without increasing the compressor, the area occupied is small, the cost is low, and the different needs of users can be met.

[0018] Finally, it should be noted that: the above only for the preferred embodiments of the present application, and is not intended to limit the present application, although the foregoing embodiments of the present application has been described in detail, for the skilled in the art, it still can be modified, or for part of the technical features of the equivalent replacement, the spirit and principles of the present application, made any modification, equivalent replacement, improvement, etc., should be included within the scope of the present application.

Claims

1. A novel nitrogen production device, comprising an air compressor, a pre-cooling unit, a purification system and a fractionating tower connected in sequence; raw air is compressed by the air compressor, cooled by the pre-cooling unit, and then enters the purification system; after water, carbon dioxide and hydrocarbons in the raw air are adsorbed in the purification system, the raw air enters the fractionating tower; in the main heat exchanger of the fractionating tower, the air exchanges heat with the returned oxygen-rich gas and nitrogen gas, the temperature is reduced to near the air liquefaction point, and the air enters the rectifying tower for rectification, and high-purity nitrogen gas is obtained at the top of the rectifying tower; part of the high-purity nitrogen gas is used as product nitrogen gas, reheated by the main heat exchanger, and then discharged from the fractionating tower and sent to the user; characterized in that: Another part of the condensed liquefied liquid nitrogen is output as a product, and another part is re-input into the rectification tower as reflux liquid. Oxygen-rich liquid air extracted from the bottom of the rectification tower is subcooled by a cold device and throttled to evaporate in a main heat exchanger. Part of the evaporated oxygen-rich liquid air enters a subcooler, and then enters the main heat exchanger to be reheated. The re-heated oxygen-rich liquid air enters an expander to be cooled, and then enters the rectification tower after being reheated by the main heat exchanger. The oxygen-rich gas after expansion is used as regeneration gas and cold blowing gas of a purification system. Part of the liquid air is throttled to enter the subcooler to be vaporized, and then is combined with the oxygen-rich gas after expansion. The rectified liquid nitrogen is reheated by a liquid nitrogen pump in the main heat exchanger, and is used as another product nitrogen gas.

2. The novel nitrogen generation plant of claim 1, characterized by: The main heat exchanger in the rectification tower comprises two groups of first and second main heat exchangers connected in series.

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