JPS6115507Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a condenser for air separation equipment.
The purpose is to recover Zenone in good yield.

Generally, krypton and non-oxygen are produced by extracting liquefied oxygen containing extremely small amounts of krypton and xenone from the main condenser of an air separation device and concentrating it by rectification. The one shown in Fig. 1 is an example of an air separation device used in the production of krypton and xenone. Pretreated and cooled compressed feed air is passed from pipe 1 to lower column 2 of a double rectification column. is introduced and rectified. Oxygen-rich liquefied air is distilled at the bottom of the lower column 2, and liquefied nitrogen is distilled from the upper part.The liquefied air passes through a pipe 5 and a valve 6, and the liquefied nitrogen passes through a pipe 7 and a valve 8, respectively, to the upper column. 3
is supplied to It is further rectified in the upper column 3, and oxygen is separated in the lower part of the upper column 3 and nitrogen is separated in the upper part.
Liquefied oxygen is extracted through pipes 9 and 10, respectively, and distilled into the main condenser 4. This liquefied oxygen contains krypton, which exists in extremely small amounts in the air.
It contains xenone, which is extracted from the tube 11, concentrated by rectification to form a krypton and xenone mixture, and further rectified to separate krypton and xenone.

In this way, krypton and xenone can be obtained by concentrating the liquefied oxygen distilled into the main condenser 4 of the air separation device, but if the amount of liquefied oxygen extracted is small, the concentration of krypton and xenone in the liquefied oxygen will increase. As a result, the concentration of krypton and xenone in the product oxygen gas discharged from the pipe 9 becomes high, resulting in a low recovery rate of krypton and xenone. Therefore, if the amount of liquefied oxygen extracted is increased, krypton,
Although the recovery rate of Zenon is increased, the scale of the concentration and purification process for krypton and Zenon becomes large, which is disadvantageous and uneconomical.

This idea was made in view of the above circumstances,
The purpose of the present invention is to provide a condenser for air separation equipment that can increase the recovery rate of krypton and xenone even though the amount of liquefied oxygen extracted is small and the concentration and purification steps are small-scale. The condenser is divided into two units, and the liquefied oxygen that has flowed down from the upper column passes through the first condenser and flows into the second condenser, and the product oxygen gas is extracted from the first condenser, and krypton, xenon, etc. This device is characterized in that the liquefied oxygen for collection is extracted from the second condenser.

This invention will be explained in detail below with reference to the drawings.

FIG. 2 shows an example of this invention, and the same components as those shown in FIG. 1 are denoted by the same reference numerals, and their explanation will be omitted.

In the air separation apparatus shown in FIG. 2, a first condenser 12 made of a plate-fin type heat exchanger and a second condenser 13 made of a plate-fin type heat exchanger are installed approximately in the center of the rectification column. , two units are built-in. The first condenser 12 is provided directly below the upper column 3, and the second condenser 13 is provided directly below the first condenser 12.
It is located below. Further, a lower column 2 is provided in each of the first condenser 12 and the second condenser 13.
A pipe 14 that sends nitrogen gas from the first condenser 12 and the second condenser 13, a pipe 16 that sends the liquefied nitrogen liquefied in the first condenser 12 and the second condenser 13 to the liquefied nitrogen reservoir 15 provided above the lower column 2, and A pipe 17 that allows the discharged liquefied oxygen to flow down into the first condenser 12, a pipe 18 that allows the liquefied oxygen to flow down from the first condenser 12 to the second condenser 13, and oxygen vaporized in the second condenser 13. A pipe 19 is provided to guide the gas to the lower part of the upper column 3 as rising gas of the upper column 3. Further, above the first condenser 12, product oxygen gas is extracted from the oxygen gas generated in the first condenser 12 through a pipe 9, and the remainder is used as rising gas in the upper column 3. A partition plate 20 is provided to prevent oxygen gas rising from the second condenser from being mixed in. This partition plate 20 is a plate-shaped body with a small-diameter opening formed therein, or a plate-shaped body arranged so as to form an opening above the condenser 12, and is a plate-shaped body arranged so as to form an opening above the condenser 12. It is attached so as to be partitioned from the first condenser 12.

In the condenser with the above structure, the liquefied oxygen distilled below the upper column 3 naturally flows down the pipe 17,
It enters the first condenser 12 and is heated and vaporized by the nitrogen gas introduced from the lower column 2 via the pipe 14 into the nitrogen passage of the first condenser 12 . A part of this oxygen gas is extracted from the pipe 9 at the bottom of the partition plate 20 and becomes a product oxygen gas, and the remainder rises in the upper column 3 through the opening of the partition plate 20. The liquefied oxygen in the first condenser 12 then flows down the tube 18 into the second condenser 13 and from the lower column 2 into the tube 1
4 into the second condenser 13, the nitrogen gas is heated and vaporized. This oxygen gas is guided below the upper column 3 through a pipe 19, vaporized in the first condenser 12, merges with the oxygen gas that has passed through the partition plate 20, and becomes the rising gas in the upper column 3. . In addition, the first and second condensers 12, 13
The liquefied nitrogen supplied to and liquefied flows through the pipe 16,
The liquefied nitrogen accumulates in a liquefied nitrogen reservoir 15 provided above the lower column 2. A part of this liquefied nitrogen passes through the pipe 7 and expands at the valve 8, and then is led to the upper column 3 and becomes the reflux liquid in the upper column, and the remainder becomes the reflux liquid in the lower column 2. Furthermore, the liquefied oxygen in the second condenser 13 is extracted through the pipe 11 and is supplied as krypton and xenone raw material liquid to a concentration and purification process (not shown).

As explained above, the condenser for air separation equipment of this invention has two condensers, the first condenser and the second condenser, built into the rectifying column, and the distillate in the upper column is liquefied. Pipes are arranged so that oxygen flows sequentially into the first and second condensers in series, and liquefied oxygen for producing krypton and xenone is extracted from the second condenser, and the vaporized oxygen gas in the first condenser is used as a product. It is constructed so that it can be extracted as oxygen gas. Therefore, with an air separation device equipped with a condenser with this structure, even if the amount of liquefied oxygen extracted for producing krypton and xenone is reduced, less krypton and xenon will escape into the product oxygen gas, and this As a result, the recovery rate of krypton and xenon becomes extremely high.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the structure of a conventional air separation device, and FIG. 2 is a schematic diagram showing the structure of the condenser for the air separation device of this invention. 2... lower tower, 3... upper tower, 9, 11...
Pipe, 12...First condenser, 13...Second condenser 14...Pipe, 15...Liquid nitrogen reservoir, 16,
17, 18, 19...pipe, 20...partition plate.

Claims (1)

[Scope of utility model registration request] A first condenser and a second condenser are installed in series between the upper column and the lower column of a double rectification column consisting of an upper column and a lower column, and the liquefied oxygen flowing down the upper column is A pipe for flowing liquefied oxygen from the first condenser to the second condenser, a pipe for sending nitrogen gas from the lower column to the first and second condensers, and a pipe for sending nitrogen gas from the lower column to the first and second condensers. A pipe that flows the liquefied nitrogen liquefied in the second condenser to the liquefied nitrogen pool in the upper part of the lower column, and
A pipe that guides the oxygen gas vaporized in the condenser to the lower part of the upper column, and an opening placed above the first condenser to extract a part of the oxygen gas vaporized in the first condenser as product oxygen gas. 1. A condenser for an air separation device, comprising: a partition plate having a partition plate; and a pipe for extracting liquefied oxygen from the second condenser and sending it to a krypton and xenone purification process.