JP2616900B2 - How to make the temperature distribution of the adsorbent uniform - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for uniformizing the temperature distribution of an adsorbent in a pressure swing adsorption tank.

[0002]

2. Description of the Related Art Conventionally, when a zeolite molecular sieve is used as an adsorbent and air is introduced under pressure by a pressure swing method to adsorb and separate nitrogen gas and concentrate and recover oxygen gas, nitrogen gas is introduced into pores of the zeolite molecular sieve. Approximately 0.2kc per 1Nl of adsorbed gas with preferential adsorption
The separated gas while generating the heat of al and increasing in temperature moves to the adsorption tank outlet side, and the generated heat is taken out of the adsorption tank as sensible heat by the gas. On the other hand, when nitrogen is desorbed and regenerated at a pressure lower than the pressure at the time of adsorption, heat is reversibly absorbed at the time of adsorption, the temperature drops due to the adiabatic cooling phenomenon, and the adsorbent closer to the adsorption tank inlet side is cooled. If this temperature is too low, the strongly adsorbing water or CO ₂ in the gas will further increase the adsorbing power with the adsorbent, which makes it more difficult to desorb and accumulates in the adsorbent layer, resulting in the accumulation of nitrogen and It is estimated that the oxygen separation efficiency decreases.

[0003]

When the above-mentioned adsorption and desorption phenomena are repeated, the temperature distribution as shown in FIG. 1 becomes visible, and the temperature gradient of the adsorbent due to the filling height becomes remarkable. In order to improve this and to make the temperature distribution of the adsorbent uniform, the present inventors have invented to arrange the outlet pipe of the adsorption tank through the adsorbent in order to exchange heat between the outlet gas and the adsorbent. .
Further, in the pressure swing method, gas may flow instantaneously in the pipe, and at that time, a high temperature is generated, which causes noise to the outside. The present inventors have found that if the outlet gas passage penetrates through the adsorbent-filled layer as described above, it is also effective in preventing this noise.

According to the present invention, when the adsorption tank is filled with zeolite molecular sieve or carbon molecular sieve and the mixed gas is adsorbed and separated by the pressure swing method, the temperature of the adsorbent tank outlet gas is higher than the inlet gas.
By heating the adsorbent at the inlet of the adsorption tank whose temperature has dropped below the inlet gas and supplying the necessary thermal energy during desorption regeneration, the desorption regeneration capacity is increased and the gas flows in the outlet pipe at a high speed. It is an object of the present invention to provide a method for making the temperature distribution of an adsorbent uniform by using an adsorbent layer capable of reducing noise generated at the time. In particular, in the case of a mixed gas containing oxygen and nitrogen as main components, the temperature difference becomes large, so that the present invention can be used more advantageously.

[0005]

That is, the gist of the present invention is as follows.
When the mixed gas is adsorbed and separated by the pressure swing method, it is arranged so as to penetrate through the adsorbent packed layer so that the adsorbent is heated and discharged at the time of adsorption by the adsorption tank outlet gas that holds the heat of adsorption as sensible heat. The present invention relates to a method for making an adsorbent temperature distribution uniform, wherein an outlet gas of an adsorption tank is passed through a plurality of provided through-tubes.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The adsorption tank of the present invention has a structure in which an adsorption tank outlet nozzle and an outlet gas passage are integrated, and the inside of the adsorbent packed layer is penetrated by at least one, preferably a plurality of through tubes. Thereby, the heat quantity brought out by the gas at the outlet of the adsorption tank as sensible heat can be recovered by heat exchange when the gas at the outlet of the adsorption tank passes through the through-tube, and the adsorbent can be heated. As a result, as shown in FIG. 1, the temperature distribution of the adsorbent is made uniform, and a decrease in the adsorption separation efficiency can be prevented.

[0007]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. Example 1 In a case of a cylindrical vertical type as a specific structure, as shown in FIG. 2 or FIG. 3, since an outlet gas passage is incorporated in an adsorption tank so as to be wrapped with an adsorbent as a penetrating pipe, gas emitted from the pipe is used. The flow noise is absorbed by the adsorbent, and no soundproofing measures are required. In particular, as the number of through tubes is increased as shown in FIG. 3, the heat recovery effect becomes greater. Therefore, a preferred embodiment of the present invention includes an adsorption tank having a plurality of through-tubes. When such an adsorption tank is used, uniformization of the adsorbent temperature distribution can be efficiently achieved.

[0008]

The lower layer of the adsorbent is heated by the gas passing through the pipe penetrating through the interior of the adsorbent, so that heat energy required for desorption regeneration is supplied by heat exchange, and the adsorbent in the tank is supplied. Is uniformed, and the desorption / regeneration capability is increased. In addition, since the pipe penetrates through the adsorbent-filled layer, the adsorbent becomes a sound absorbing material, so that soundproofing measures are not required. On the other hand, as the size of the apparatus increases, the tendency of the temperature to become non-uniform increases, so that the present invention can be used more effectively.

[Brief description of the drawings]

FIG. 1 is a curve showing a filling height and an adsorbent temperature distribution in an adsorption tank, showing a difference between before improvement (conventional device) and after improvement (device of the present invention).

FIG. 2 is a schematic diagram showing a state in which one penetrating tube is provided and penetrated into an adsorbent packed layer.

FIG. 3 is a schematic view showing a state in which five penetrating pipes are provided and penetrated into an adsorbent packed layer.

Claims (1)

(57) [Claims] 1. When adsorbing and separating a mixed gas by a pressure swing method, the adsorbent packed layer is heated and discharged at the time of adsorption by an adsorbing tank outlet gas which holds adsorption heat as sensible heat. A method for making the temperature distribution of an adsorbent uniform, wherein an outlet gas of an adsorption tank is passed through a plurality of through-tubes arranged so as to penetrate the adsorbent.