SU1558443A1 - Method and apparatus for adsorption extraction of crypton-xenon mixture - Google Patents

Abstract

This invention relates to a technique for the separation of gases and liquids by adsorption and can be used in the chemical industry. The purpose of the invention is to increase productivity and reduce the energy intensity of the process. A method of continuous adsorption extraction of a krypton-xenon mixture, comprising feeding the original krypton-xenon concentrate into an adsorption unit, followed by replacing the adsorbed oxygen with nitrogen and thermal desorption. In the proposed method, an adsorbent in the form of a rotating ring layer is used, and the source of krypton-xenon concentrate and replacement nitrogen adsorbed oxygen is continuously supplied to the adsorber. Moreover, both fed to the adsorber flow is supplied at the same pressure and temperature corresponding to the temperature of the saturated vapor mixture. In addition, the speed of movement of the adsorbent should not be less than the speed of movement of the adsorption front of krypton, preferably 2.76 ^. 10 ^-4 m / s. The temperature of the concentrate supplied for adsorption is preferably 90.5 K, the temperature of the replacement nitrogen is 77.5 K, the pressure is 0.11 MPa. A device for carrying out adsorption extraction of a krypton-xenon mixture includes a housing and a moving annular adsorber located inside the housing, provided with sealing plates around the perimeter of the axial section. 2 sec. f-ly, 2 zp f-ly, 3 ill.

Description

This invention relates to a technique for the separation of gases and liquids by adsorption and can be used in the chemical industry.

The purpose of the invention is to increase productivity and reduce the energy intensity of the process.

Figure 1 is given a device, a general view, axonometrics; figure 2 is the same section; on fig.Z - the same plan.

The device comprises a housing consisting of the upper 1 and the lower 2 parts, having a heat insulating lining (not shown) on the outside,

interconnected by bolts and gaskets along the flange. An adsorbent 3 (for example, KSM-5 grains in the form of granules) is located in the casing, which is located inside a one-piece annular adsorber. Adsorber h is mounted on a rolling bearing 5. Inside the adsorber k there are electric heaters of the soloid type. Sealing plates 7 are located on the surface of the adsorber C along the perimeter of the axial section. On the surface of the upper part of the housing 1, channels 8 are fed in for supplying and discharging gases with nozzles 9-12. The rotational drive of the adsorber k consists of a gear-driven electric motor 13 with internal gearing. On the surface of the upper part of the housing 1, in the locations of the channels 8 for supplying and discharging gases, there are holes 15. The electrical contacts 16 are fixed at the bottom of the housing 2. The sockets 17 and 18, intended for supplying the krypton-xenon concentrate and nitrogen replacing oxygen on channels 8 of the supply and removal of gases. The method is implemented as follows.

Krypton-xenon concentrate, consisting mainly of oxygen, a krypton-xenon mixture of 0.1% and impurities of methane up to 0.05%, comes in the form of saturated steam under a pressure of 0.11 IPa and a temperature of 90.5 K at port 17 the corresponding gas supply channel 8, through the holes 15 into the gas-permeable annular adsorber k on the surface of the adsorbent 3; 10 4 m / s. Through pipe 18, nitrogen adsorbed to oxygen at a temperature of -77 5 K and a pressure of 0.11 MPa enters the adsorber. Moreover, the pressures of krypton-xe-carbon concentrate and nitrogen continuously supplied to the adsorber should be equal to each other. In this case, the direction of movement of the incoming krypton-xenon concentrate and nitrogen inside the adsorber will be opposite and they will separate, since the front of the two streams with the same pressure is formed at the site of the adsorber between nozzles 17 and 18. The flow of krypton-xenon concentrate entering the adsor

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taking the pipe 17, flows towards the moving adsorbent 3, cooling it (the direction of rotation of the adsorbent is shown by arrows in FIG. 3, and the direction of flow of the nitrogen replacing oxygen coincides with the direction of movement of the adsorbent

3).

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In the process of cooling the adsorbent 3, the gases of the krypton-xenon concentrate are adsorbed. Moreover, the adsorption takes place under conditions of a dynamic saturation of the adsorbent with krypton-xenon concentrate, since non-adsorbed oxygen is continuously withdrawn from the adsorber through pipe 9. Adsorbed the krypton-xenon mixture with oxygen and methane impurities is carried away by the moving adsorbent 3 to the adsorbents which is located on the adsorber between the nozzles 10 and 18. Nitrogen replaces the adsorbed oxygen when it is adsorbed on silica gel, for example, grade KSM-5, without affecting the adsorption to ripton-xenon mixture. Therefore, when nitrogen is supplied to the adsorber through pipe 18 and discharged through pipe 10 along with nitrogen, the replaced oxygen is removed from the adsorber. In the adsorber k between the nozzles 10 and 12, there is a desorption zone. Thermal desorption is carried out by heating the adsorbent with 3 electric heaters 6 which are connected via electrical contacts 16 when the adsorber section is saturated with a krypton-xenon mixture into the desorption zone. The number of electric heaters used in the device should beat at least 10-12 pieces. The electrical contacts 16 shown in FIG. 2 are shown conventionally, since in reality they are in the desorption zone and have electrical leads for connecting them to a current source (not shown). At the first stage of thermal desorption, when the adsorbent 3 is heated by electric heaters 6, nitrogen is desorbed with impurities of non-substituted nitrogen, as the most weakly adsorbing components that are removed from the adsorber through the nozzle 11.

At the second stage of thermal desorption, when the adsorbent is heated to 200 ° C, a krypton – xenon mixture with impurities of non-adsorbed nitrogen, oxygen and methane desorbs, which is removed from the adsorber by means of a pipe 12. After desorption, an adsorber driven by an electric motor 13 is gear driven It moves on rolling bearings 5 to the adsorption zone, where it is cooled due to the cold vapors of the krypton-xenon concentrate flowing towards them and again adsorbs the krypton-xenon mixture. Moreover, since the adsorbent 3 is cooled by the saturated vapors of a krypton-xenon concentrate, there is no need for a device for a special heat exchanger for cooling the adsorbent 3. Since the linear velocity of the adsorber is equal to 2j76 10 m / s, not less than the speed of movement of the adsorption front of krypton, equal to 2.75 Yu m / s, almost all of the krypton-xenon mixture is delayed by the adsorbent. In addition, methane is also delayed by the adsorbent, although its rate of movement of the adsorption front is 5 times greater than that of krypton. Therefore, to reduce the explosiveness of the process of further processing of the resulting krypton-xenon mixture, it is necessary to replace the adsorbed oxygen with nitrogen (a mixture of methane and oxygen is explosive). In addition, in the proposed device, sealing plates 7 allow you to restrict gas leaks inside the adsorber body over its inner surface, which leads to a decrease in the losses of krypton-xenon concentrate per peretechki and increase productivity. Cooling the adsorbent with the help of saturated vapors of a krypton-xenon concentrate can significantly reduce the energy intensity of the process of extracting a krypton-xenon mixture, since the crypto-xenon concentrate is produced in a liquid form, and its saturated steam can be obtained by instantaneous evaporation when fed into adsorber through pipe 17.

As shown by the calculations in the adsorber with dimensions in mm, in

200 mm (see Fig. 2) and the equivalent diameter (a, b) / 195 mm and the ratios of the average diameter of the target toroid D and the equivalent diameter of the section, d ranging from 5 to 6.9, while feeding 0, 01 m3 / s krypton-xenon concentrate and 0.01 m3 / s replacement

nitrogen adsorbed oxygen, you can extract 7.9i Yu m3 / s krypton-xenon mixture composition,%: krypton-xenon smzs 79.2, nitrogen 19.8, oxygen 1.0, and

5 insignificant amount of methane to 0.05.

The use of the invention reduces the energy consumption of the process of extracting a krypton-xenon mixture,

0 since the krypton-xenon concentrate is fed into the annular adsorber at the temperature of saturated vapors, which eliminates the need to install a heat exchanger, since

5, the adsorbent is cooled by saturated concentrate vapor fed to the adsorber.

When processing 15.15 m3 of a krypton-xenon mixture by the proposed method, the productivity of the extraction process is 25 m3 / h, which is 5.77 times higher than when processed by a known method, while the energy-holding capacity of the process decreases as compared to the known value of A, 3b kW .

Claims (3)

1. The method of adsorption extraction Q or krypton-xenon mixture of krypton-xenon concentrate, which includes feeding the concentrate to an adsorbent layer of silica gel granules, the subsequent replacement of adsorbent oxygen by nitrogen transmission and thermal desorption, due to the fact that, in order to increase productivity and reduce the energy intensity of the process, 0, the adsorbent is used in the form of a rotating annular layer, the concentrate is fed, nitrogen is passed and thermal desorption is carried out continuously, the concentrate is adsorbed and nitrogen is 5, the oxygen substitution is served as saturated vapor at the same pressure. 2. Method pop. 1, differing from the fact that the process is conducted at a temperature of 90.5 K for the adsorption of concentrate and a temperature of replacement nitrogen for 77.5 K at a pressure of 0.11 MPa „ 3. The method according to claims 1 and 2, characterized in that the rotation of the layer of the adsorbent is carried out with a linear speed of 2.76-1 m / s. k. Adsorption extraction device for krypton-xenon mixture including a rotating annular body with nozzles and channels for gases with an annular sorbent layer located therein, characterized in that, in order to increase productivity and reduce the energy intensity of the process, it is provided around the perimeter of the axial section of the annular sorbent layer with sealing plates. , one AND FIG. one / 7 i-1 g IB Physical