A rectification apparatus for liquid air separation
By incorporating a pressurized expansion structure consisting of a nitrogen compressor and a turbine expander in the liquid air separation unit, the problems of high load and insufficient cooling capacity in small liquid air separation units have been solved, resulting in more efficient liquid oxygen production and improved equipment durability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 开封黄河空分集团有限公司
- Filing Date
- 2025-07-15
- Publication Date
- 2026-06-09
AI Technical Summary
Existing small-scale liquid air separation units operate under high loads and lack sufficient cooling capacity carried by the raw air, resulting in poor equipment durability and frequent maintenance.
A liquid air separation distillation apparatus is used. By setting up a first nitrogen compressor unit and a first turbine expander on the first waste nitrogen gas delivery pipe, the waste nitrogen gas is pressurized and then sent to the expansion end of the first turbine expander for expansion and cooling to form a cold source. Part of the separated raw material air enters the lower column as gaseous distillation feedstock, while the other part enters the second main heat exchanger to liquefy into liquid air, which carries more cooling capacity into the lower column.
It reduced the operating load of the equipment, increased the cooling capacity carried by the raw material air, increased the production of liquid oxygen, and improved the durability and efficiency of the equipment.
Smart Images
Figure CN224331537U_ABST
Abstract
Claims
1. A liquid air separation distillation apparatus, comprising a distillation column and a first main heat exchanger (1), wherein the distillation column comprises, from top to bottom, an upper column (2), a main condenser-evaporator (3), and a lower column (4), characterized in that: The first main heat exchanger (1) and the lower tower (4) are provided with raw material air conveying pipes (5). The raw material air conveying pipe (5) between the first main heat exchanger (1) and the lower tower (4) is provided with the inlet end of a liquefied air conveying pipe (6). The inlet end of the liquefied air conveying pipe (6) is connected to the outlet end of the raw material air conveying pipe (5) and the liquefied air conveying pipe (6) between the lower tower (4). The liquefied air conveying pipe (6) is provided with a second main heat exchanger (7). The upper tower (2) and the first main heat exchanger (1) are provided with a first waste nitrogen conveying pipe. (8) A first nitrogen compressor unit (9) is installed on the first waste nitrogen gas delivery pipe (8) on the side of the first main heat exchanger (1) away from the upper tower (2). A pressurization end of the first turbine expander (10) is installed at the outlet end of the first waste nitrogen gas delivery pipe (8). A second waste nitrogen gas delivery pipe (11) is installed on the pressurization end of the first turbine expander (10), the first main heat exchanger (1) and the expansion end of the first turbine expander (10). A third waste nitrogen gas delivery pipe (12) is installed on the expansion end of the first turbine expander (10) and the first main heat exchanger (1).
2. The liquid air separation distillation apparatus according to claim 1, characterized in that: The upper tower (2) and the first main heat exchanger (1) are provided with a first nitrogen delivery pipe (13). A first regulating valve (14) is provided on the first nitrogen delivery pipe (13) on the side of the first main heat exchanger (1) away from the upper tower (2). A second nitrogen delivery pipe (15) is provided on the first nitrogen delivery pipe (13) between the first regulating valve (14) and the first main heat exchanger (1). An expansion nitrogen return pipe is sequentially provided on the second nitrogen delivery pipe (15) along the direction from near the first nitrogen delivery pipe (13) to away from the first nitrogen delivery pipe (13). The outlet end of (16), the second nitrogen compressor unit (17), the inlet end of the liquefied nitrogen delivery pipe (18), the second regulating valve (19) and the boosting end of the second turbine expander (20), the boosting end of the second turbine expander (20), the second main heat exchanger (7) and the expansion end inlet of the second turbine expander (20) are provided with a third nitrogen delivery pipe (21), the expansion end outlet of the second turbine expander (20) and the inlet end of the expansion nitrogen return pipe (16) are connected, and the third regulating valve (22) is provided on the liquefied nitrogen delivery pipe (18).
3. The liquid air separation distillation apparatus according to claim 2, characterized in that: A liquid nitrogen storage tank (23) is provided at the outlet end of the liquefied nitrogen delivery pipe (18). A liquid nitrogen delivery main pipe (24) is provided on the heat source channel of the main condenser evaporator (3) and the liquid nitrogen storage tank (23). A liquid nitrogen vaporization delivery main pipe (25) is provided on the liquid nitrogen storage tank (23) and the second main heat exchanger (7). A liquid nitrogen pump (26) and a fourth regulating valve (27) are provided on the liquid nitrogen vaporization delivery main pipe (25) between the liquid nitrogen storage tank (23) and the second main heat exchanger (7). The outlet ends of the first nitrogen delivery pipe (13) and the liquid nitrogen vaporization delivery main pipe (25) between the expansion nitrogen return pipe (16) and the second nitrogen compressor unit (17) are connected. A one-way valve (28) is provided on the liquid nitrogen vaporization delivery main pipe (25) between the second main heat exchanger (7) and the first nitrogen delivery pipe (13) and the expansion nitrogen return pipe (16).
4. The liquid air separation distillation apparatus according to claim 3, characterized in that: The top of the lower tower (4) is connected to the inlet end of the heat source channel of the main condenser evaporator (3). The liquid nitrogen delivery main pipe (24) is sequentially provided with the inlet end of the first liquid nitrogen reflux pipe (29), the first heat source channel of the first subcooler (30), the inlet end of the second liquid nitrogen reflux pipe (31), and the fifth regulating valve (32) along the direction from the main condenser evaporator (3) to the liquid nitrogen storage tank (23). The upper tower (2), the second heat source channel of the first subcooler (30), and the lower tower (4) are provided with An oxygen-enriched liquid air delivery pipe (33) is provided. A liquid air pump (34) is installed on the oxygen-enriched liquid air delivery pipe (33) between the first subcooler (30) and the lower tower (4). The outlet end of the first liquid nitrogen reflux pipe (29) is connected to the top of the lower tower (4). The inlet end of the second liquid nitrogen reflux pipe (31) is connected to the top of the upper tower (2). A sixth regulating valve (35) is installed on the first liquid nitrogen reflux pipe (29), the second liquid nitrogen reflux pipe (31), and the oxygen-enriched liquid air delivery pipe (33).
5. The liquid air separation distillation apparatus according to claim 3, characterized in that: The liquid nitrogen pump (26) is located between the liquid nitrogen storage tank (23) and the fourth regulating valve (27). The main liquid nitrogen vaporization conveying pipe (25) between the liquid nitrogen pump (26) and the fourth regulating valve (27) is equipped with the inlet end of the liquid nitrogen conveying branch pipe (36). The seventh regulating valve (37) is installed on the liquid nitrogen conveying branch pipe (36). The liquid nitrogen vaporizer (38) is installed on the outlet end of the liquid nitrogen conveying branch pipe (36).
6. The liquid air separation distillation apparatus according to claim 1, characterized in that: The first waste nitrogen gas conveying pipe (8) between the upper tower (2) and the first main heat exchanger (1) is provided with a cold source channel for the second subcooler (39). The heat source channel of the second subcooler (39) and the cold source channel of the main condenser evaporator (3) are provided with a liquid oxygen conveying pipe (40). The raw material air conveying pipe (5) between the inlet end of the liquefied air conveying pipe (6) and the outlet end of the liquefied air conveying pipe (6) and the liquefied air conveying pipe (6) are respectively provided with an eighth regulating valve (41).