JPS58138973A - Method of separating air - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for liquefying and separating air, and more particularly to a method for economically producing high-purity fII violet by separating static electricity using an all-low pressure system. .

By liquefying air and distilling it into M, N25o2sAr
Air liquefaction separation equipment that separates
I'm moving. In this air liquefaction separation equipment, it is necessary to pressurize and depressurize the raw air and product oxygen according to the operating conditions, so a compressor is used.

F&pupils of equipment such as expanders are essential. Of the power required for such equipment, the power for f+ rice in particular occupies a large proportion, and the power cost of the compressor accounts for most of the #1 power cost of the air liquefaction separation device. It's central. In particular, many air liquefaction separation devices have a large capacity and the power cost is high, so there is a strong desire to reduce the power cost as part of efforts to reduce the manufacturing cost of product oxygen. These circumstances are exactly the same in the so-called total low-pressure air separation method, but no effective measures have been taken.

Conventional all-low pressure air separation methods are generally carried out according to a system diagram as shown in FIG. That is, raw air is supplied from the air filter 1 and compressed by the pneumatic compressor 2 at approximately 4°6 at.
After the a4C pressurized sardine is pressurized, it is cooled in the aftercooler 8. Next, it enters the reversible heat exchanger 4, where it exchanges heat with the product oxygen and impure nitrogen and is cooled in a trench near the boiling point. ) 5 into the lower @l condenser 6, and the condenser 6 connects the upper tower 6.
It is supercooled to below the boiling point by heat exchange with the reflux liquid.

Therefore, some of them are willing to liquefy. Next, it is separated into gaseous air and liquid air in a liquid separator 7, and the liquid air is led to a total JitM distillation column intermediate pressure column (hereinafter simply referred to as "lower column") 8. The liquid air introduced into the lower tower 8 is electrified and becomes a rising gas, while it is brought into contact with the reflux liquid (F&), which is compressed and damaged at the top of the lower tower 8, and remains in the lower column. Am rich gas is obtained at the top of the column 8, and the reflux liquid becomes liquid air with an oxygen content of about 40% at the bottom of the lower column 8. The gaseous air extracted from the middle part of the lower tower 8 enters the expansion turbine 9 through pipes 81 and 82, where it is cooled and then guided to the upper tower 5 through a pipe 88.

The liquid air which has been converted into crude N4Iii & as described above in the lower column 8 is introduced into the liquid gL subcooler 10 through the pipe a4 and cooled, and then is sent from the pipe 85 to the top of the crude argon column 11. A second capacitor 12 is provided, and the capacitor 1
2, the liquid static electricity is gasified by heat exchange with the argon-rich gas in the crude argon column 1'l, and is then discharged from the pipe 86 to the upper column 5. On the other hand, the nitrogen-rich liquid stored at the top of the lower tower 8 is introduced into the liquid air supercooler 10 through a pipe 87 and cooled, and then guided to the upper part of the upper tower 6 through a pipe 88. The gaseous air separated by the gas-liquid separator 7 is sent from the pipe 27 to the liquefier 1.
After being completely liquefied while passing through pipe 29. i4N
Body pneumatic supercooler 10. It is guided to the upper part of the upper tower 5 via a pipe 80. Furthermore, the rich oxygen liquid of 11iIi purity, which has already been separated in the #1 distillate in the upper column and stored at the bottom, is extracted from the bottom of the upper column 5 and passes through the pipe 51 to the lower part of the crude argon column 11. guided and further stored. After this, the crude argon column 11
After extracting high-purity oxygen-rich gas from the bottom of the pipe 45, it is guided to the liquefier 1B through the pipe 4B. The liquefier 18
The temperature inside is slightly tIl! The recovered high-purity oxygen-rich gas is then introduced into the reversible heat exchanger 4 through a pipe 47, where it is gradually restored to its pJ value. After being introduced and pressurized, it is recovered to the outside as product oxygen.

By the way, in order to smoothly recover even finer oxygen using the total low-pressure air separation method as described above, it is necessary to maintain the inside of the crude argon column at a reduced pressure of about Q, 8 ata to 1, Q ata, and at the time of recovery. The pressure of the product oxygen is about 160 ata-1,2
It is necessary to regulate ata4C. Therefore, in the conventional all-low-pressure air separation method, an oxygen compressor 1 is installed in the middle of the pipe 48 that passes through the reversible heat exchanger 4 and extracts oxygen from the leather product.
By disposing the crude argon column 11 and vacuuming the crude argon column 11, the above condition (2) is satisfied, and the crude argon column 11
After about 0.8a~1.0ata is extracted from the lower part of the
By compressing the product oxygen, the pressure drop decreases at approximately 1.
The pressure was adjusted to 2ata to satisfy the condition (2) above. ζρ-like Kjt41R Since a large-scale oxygen pressure machine is used to reduce and increase pressure in a small range, it still causes a rise in power costs and is a rate-limiting factor in improving the economic efficiency of the air separation equipment as a whole. It becomes.

Therefore, in the all-low-pressure air separation method, the above-mentioned ①.

It has been desired to develop a technology that can reduce as much as possible the power cost required for the means to satisfy the operating conditions (2) while satisfying these conditions.

The present invention has been made in view of these circumstances, and its purpose is to discontinue the use of the above-mentioned oxygen compressor in a total low-pressure air separation system and to organically combine a separate new technical means. KotoKoshi, while satisfying the operating conditions of ■ and ■ above, the 1 required for conventional silicon compression machines.
The purpose is to reduce power costs and thereby improve the economic efficiency of the entire low-pressure air separation system Vj1111.

However, the air separation method of the present invention, which has achieved such a purpose, adds the operating conditions of (2) above (by extracting the rich argon gas at the top of the crude argon column with a blower), while The gist of this method is that liquid oxygen is extracted from the lower part of the tower below the liquid level, and is self-pressurized by the action of an electric power of 11 volumes of D liquid I, thereby satisfying the operating condition (2) above. .

The configuration and effects of the present invention are explained below based on the drawings of the examples.
To be clear, the lower ki sasai is only a representative example of the jii IC, and it goes without saying that the shiki sasai can be changed according to the spirit of the above and after.

Section 2.1 shows a system diagram of the all-low-pressure electrostatic separation method of the present invention, and the basic structure is the same as that of the conventional example in FIG. The attached 31 dice are the conventional example and 1! 4, and the features are in the configuration of the top and bottom of the crude argon column 11' and the pipe line 48'.Hereinafter, this configuration will be mainly explained, and the same configuration as the conventional example will be explained. The explanation will be omitted. That is, rich argon gas is stored at the top of the crude argon column 11', and the rich argon gas is extracted from the blower 15 through the pipe 52.

In this case, the inside of the Bon tower 11' is roughly Q, g ataN
The blower 15 is operated so as to maintain the pressure at 1, 0ata. On the other hand, high-purity oxygen-rich liquid is stored at the bottom of the crude argon tank 11', and Utaka Junharafu #1Iffl is extracted from the lower part of the liquid level through the descending pipe 45'.

In this case, they are located at four locations relative to the bottom sFi pipe 46 of the crude argon column 11', so the distance is about 0.8 a from the bottom.
taNl, about 1.2ata due to gravitational action while descending in the oxygen-rich M#i pipe 45' extracted at Oata.
self-pressurized. As a result, 4 g of pipe, 1 g of JF converter,
Conduit 47. The pressure of the oxygen which undergoes a slight pressure loss while passing through the reversible heat exchanger 4 and is recovered to the outside from the main line 48' can be adjusted to about 1.0 ata.

Books like this! In this embodiment, the pressure in the crude argon column 11' is adjusted by a blower 16 for removing the cylinder, and the pressurization mm during product oxygen recovery is carried out by self-pressurization due to a head difference. Therefore, in comparison with the configuration of the conventional example shown in Fig. 1g1, the oxygen pressure pump 14 is eliminated, but the argon-rich extraction blower 15 is added at θ.

However, the gas 9Jj and 1!1 of the blower 15 (total Vgon gas flow) are only about 1/2o of the gas processing enrichment (product enzyme flow rate) of oxygen pressure n##14, so the regulation wA Although the power cost associated with the new adoption of the rich argon extraction blower 15 is small, the large-scale savings in power cost associated with the elimination of the large-scale oxygen compressor 14 makes it possible to maintain the total low-pressure air system.
This will greatly reduce the power cost of the entire Il device.

Since the air separation method of the present invention is generally implemented as described above, it has become possible to economically produce high-purity oxygen product. Furthermore, by reducing the power required to operate the air separation device, it is possible to achieve so-called energy saving, so that it plays a large role in the industry today, when there is a strong demand for energy saving.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing a conventional all-low-pressure static separation method, and FIG. 2 is a system diagram illustrating the all-low-pressure static separation method of the present invention. 2...Pneumatic pressure - Kaki 4-Reversible heat exchanger 5...
・Low pressure column 6...1st condenser 7...9
L liquid separator 8... Medium pressure column 9... Expansion turbine 10... Liquid air subcooling reactor 11... Crude argon % 12-- Second condenser 18... Liquefier
14...Oxygen compressor 15...Blower product customer Kobe Steel, Ltd.

Claims (1)

[Claims] The feed air, which is operated by the mEE moderator and cooled by the heat exchanger, is led to the first condenser at the bottom of the low pressure column, where it exchanges heat with the liquid oxygen in the low pressure column, and the liquid enzyme is emitted aside. At the same time as the rising gas of the low pressure column, the feed air is supercooled to a conductivity below the line point to partially liquefy the rising gas, and the rising gas is brought into contact with the return t# armpit from the upper part of the low pressure column to be rectified. In this way, the reflux liquid stored at the bottom of the low-pressure column is made into an oxygen-rich liquid, while the liquefied air is introduced into the medium-pressure column and vaporized to become the rising gas of the medium-pressure column. ! Reflux liquid obtained by condensation at the top of i &C! At the same time, the reflux liquid is converted into a liquid static electricity at the bottom of the medium pressure column, and the solid air is cooled and then transferred to the crude argon column rm. In the electrostatic separation method, the liquid air is introduced into the second condenser of the crude argon column, where it exchanges heat with the rich argon gas in the crude argon column, gasified, and then introduced into the low-pressure column. # After extracting the element and self-pressurizing it by a single force action, it is gasified in a reversible heat exchanger to produce oxygen product, while the argon-rich gas at the top of the crude argon column is extracted by a blower. An air separation method characterized by maintaining the inside of an argon column in a vacuum state.