A full liquid-product air separation equipment is disclosed. The equipment comprises an air filtration system, a compression system, a precooling system, a purification system, a high-temperature expander having a first pressurizing part and a first expanding part, a low-temperature expander having a second pressurizing part and a second expanding part, a main heat exchanger having a first heat exchange pipeline, a second heat exchange pipeline, a third heat exchange pipeline, a fourth heat exchange pipeline and a fifth heat exchange pipeline, and a rectification system for rectifying air. The equipment has a simple configuration, is easy to implement, and has high gas separation efficiency and low energy consumption.

A nitrogen liquefier configured to be integrated with an argon and nitrogen producing cryogenic air separation unit and method of nitrogen liquefaction are provided. The integrated nitrogen liquefier and associated methods may be operated in at least three distinct modes including: (i) a nil liquid nitrogen mode; (ii) a low liquid nitrogen mode; and (iii) a high liquid nitrogen mode. The present systems and methods are further characterized in an oxygen enriched stream from the lower pressure column of the air separation unit is an oxygen enriched condensing medium used in the argon condenser.

A nitrogen liquefier configured to be integrated with an argon and nitrogen producing cryogenic air separation unit and method of nitrogen liquefaction are provided. The integrated nitrogen liquefier and associated methods may be operated in at least three distinct modes including: (i) a nil liquid nitrogen mode; (ii) a low liquid nitrogen mode; and (iii) a high liquid nitrogen mode. The present systems and methods are further characterized in an oxygen enriched stream from the lower pressure column of the air separation unit is an oxygen enriched condensing medium used in the argon condenser.

The present disclosure provides an energy-efficient process for preparing nitrogen and oxygen for a glass melting furnace. A device required by the process includes a filter, a turbine air compressor, an air pre-cooling unit, alternately used molecular sieve adsorbers, an electric heater, a main heat exchanger, a rectifying tower I, a main condenser-evaporator I, a rectifying tower II, a main condenser-evaporator II, a rectifying tower III, a main condenser-evaporator III, a supercooler, an expander I and an expander II. The three rectifying towers are used to prepare a low-pressure nitrogen product and an oxygen product with a certain pressure at the same time. The oxygen product with a certain pressure is used for oxygen-enriched combustion for the glass melting furnace, and the low-pressure nitrogen product is used as shielding gas of a tin bath.

Disclosed in the present invention are a pressure equalizing system for air separation purification, and a control method. The system comprises: a first air main pipe; a pressurizing gas pipeline, which is connected to the first air main pipe and used for receiving a pressurizing gas and delivering same to the first air main pipe; and a control valve, located on the pressurizing gas pipeline, and having a degree of opening regulated by the flow regulator, thereby regulating an air intake amount of the pressurizing gas pipeline. The present invention solves the problem of an air separation rectification process being affected when dry nitrogen is used for pressure equalization of an adsorber; in the switching process of entering an adsorption stage from a regeneration stage, pressurizing dry nitrogen used in a pressure equalizing step previously mixes with damp air from a main air compressor before entering the adsorber, such that the gas components flowing towards an air separation cold box remain substantially unchanged, in order to reduce disturbance in conditions of gas entering a rectification column to take part in rectification due to a gas component gradually changing from dry nitrogen to dry air in the prior art, thus stabilizing the process conditions of the air separation cold box.

An air separation apparatus and process, which produces gaseous oxygen and/or nitrogen products at an elevated pressure through internal compression of respective liquid products, are disclosed. Split-core main heat exchangers are employed to warm up product streams generated in an air rectification unit against 1) a main feed air stream in the low-pressure heat exchanger and 2) at least one boosted pressure air stream in the high-pressure exchanger. Because the boosted pressure air stream is at a higher pressure and temperature than the main feed air stream, after separate heat exchange in the split main heat exchangers, the subsidiary waste nitrogen stream exiting the high-pressure heat exchanger is also warmer than the subsidiary waste nitrogen stream exiting the low-pressure heat exchanger. The warmer waste nitrogen stream is fed into the air purification unit for regeneration purposes and the cooler waste nitrogen stream is introduced into the nitrogen water tower to perform cooling duty. The two subsidiary waste nitrogen streams are also connected on the warm side of the main heat exchangers to allow flexible distribution of the flow.

A nitrogen liquefier configured to be integrated with an argon and nitrogen producing cryogenic air separation unit and method of nitrogen liquefaction are provided. The integrated nitrogen liquefier and associated methods may be operated in at least three distinct modes including: (i) a nil liquid nitrogen mode; (ii) a low liquid nitrogen mode; and (iii) a high liquid nitrogen mode. The present systems and methods are further characterized in an oxygen enriched stream from the lower pressure column of the air separation unit is an oxygen enriched condensing medium used in the argon condenser.

The present disclosure provides an energy-efficient process for preparing nitrogen and oxygen for a glass melting furnace. A device required by the process includes a filter, a turbine air compressor, an air pre-cooling unit, alternately used molecular sieve adsorbers, an electric heater, a main heat exchanger, a rectifying tower I, a main condenser-evaporator I, a rectifying tower II, a main condenser-evaporator II, a rectifying tower III, a main condenser-evaporator III, a supercooler, an expander I and an expander II. The three rectifying towers are used to prepare a low-pressure nitrogen product and an oxygen product with a certain pressure at the same time. The oxygen product with a certain pressure is used for oxygen-enriched combustion for the glass melting furnace, and the low-pressure nitrogen product is used as shielding gas of a tin bath.

A system and method of regenerating a pre-purification vessel is provided that is particularly suitable for pre-purification of a feed air stream in cryogenic air separation unit that uses an oxygen-enriched purge gas stream for regeneration of the pre-purification unit. The disclosed pre-purification systems and methods are configured to remove substantially all of the water, carbon dioxide and other impurities from a feed air stream, optionally including hydrogen and carbon monoxide impurities. The method of regenerating a pre-purification vessel preferably involves regenerating the pre-purification vessel with an oxygen-enriched purge gas after depressurization of the vessel and thereafter partially repressurizing the pre-purification vessel with an auxiliary purge gas thereby diluting the oxygen concentration of the gases contained in the pre-purification vessel and optionally depressurizing the partially repressurized vessel.

A method and apparatus for the production of air gases by the cryogenic separation of air with front end purification and air compression can include using an available compressed dry gas such as nitrogen, oxygen, stored purified air, or synthetic air to repressurize the adsorber without diverting any of the purified air just exiting the currently on-line adsorber or changing the flow rate of the main air compressor or air sent to the cold box. This enables the main air compressor (MAC) to operate at a relatively constant flow rate while also sending a relatively constant air flow to the cold box during this repressurization step, thereby reducing the risks of process upsets and minimizing capital expenditures related to the MAC and other warm-end equipments.