JPH0326909Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an oxygen or nitrogen generator using an adsorbent that selectively adsorbs oxygen or nitrogen.

(Prior Art) FIG. 3 shows a schematic diagram of a conventional oxygen or nitrogen generator. In the figure, 1 is an air compressor, 2 is an adsorption column containing an adsorbent (such as artificial zeolite) that selectively adsorbs nitrogen or oxygen, and in the case of an oxygen generator, an adsorbent that adsorbs nitrogen well. In the case of a nitrogen generator, an adsorbent that adsorbs oxygen well is included. 3, 4, and 5 are valves for controlling adsorption and desorption of oxygen or nitrogen; 6 is a buffer tank for storing the generated high-concentration oxygen or nitrogen; 7 is a high-concentration oxygen or nitrogen supply pipe; 8
is an off-gas line that removes high concentrations of oxygen or nitrogen from the air.

The case of an oxygen generator will be explained below.

The raw air made high pressure by the air compressor 1 is passed through the valve 3.
It enters the adsorption cylinder 2 through the air, and nitrogen and other gases other than oxygen in the raw air are selectively and well adsorbed.
At the outlet of adsorption column 2, highly concentrated oxygen gas is obtained.
Enter buffer tank 6. At this time, valves 3 and 5 are open and valve 4 is closed. After this adsorption process is completed, the adsorption column 2 starts a desorption process in which the adsorbed gas (mostly nitrogen gas) is desorbed by the pressure difference between the pressure inside the adsorption column 2 and the atmospheric pressure. That is, when the adsorption cylinder 2 starts the desorption process after completing the adsorption process, the valves 3 and 5 are closed, and the valve 4 is opened. At this time, the adsorbed gas (mostly nitrogen gas) is desorbed due to the pressure difference between the internal pressure of the adsorption cylinder 2 and the atmospheric pressure, and is released through the off-gas pipe 8.

As described above, by repeating the adsorption step and the desorption step, oxygen or nitrogen can be generated intermittently. Further, by increasing the capacity of the buffer tank 6, the structure is such that oxygen or nitrogen can be continuously supplied.

However, in a conventional oxygen or nitrogen generator as shown in FIG. In most cases, it is affected by the pressure difference from atmospheric pressure), so it is necessary to have a high gas pressure or pressure difference at the outlet of the air compressor. Therefore, the adsorption cylinder 2, various valves, and piping must have a structure that can withstand high pressure, making the device expensive. In addition, even if the adsorption gas pressure difference was increased, the adsorption capacity did not improve much, and there was a limit to the concentration of oxygen or nitrogen gas that could be obtained.

(Problems to be solved by the invention) The purpose of the invention is to eliminate the drawbacks of the above-mentioned conventional equipment, to reduce the area where high-pressure gas exists in the equipment, and to improve the adsorption capacity of the adsorbent. An object of the present invention is to provide an oxygen or nitrogen generator having a mechanism capable of generating high concentration oxygen or nitrogen by utilizing not only a pressure difference but also an adsorption capacity due to a temperature difference.

(Means for Solving the Problems) The present invention provides an apparatus for generating oxygen or nitrogen using an adsorbent that selectively adsorbs oxygen or nitrogen. , relates to an oxygen or nitrogen generator characterized in that it is equipped with a heat exchanger that communicates with the high-temperature outlet of the vortex tube via a connecting pipe.

That is, the present invention provides an oxygen or nitrogen generator with a vortex tube that is inexpensive and easy to handle (no rotating parts) as a low temperature and high temperature generation mechanism.
It is characterized by being able to generate oxygen or nitrogen at a higher concentration than conventional devices.

The device of the present invention having such characteristics is useful for various oxygen or nitrogen generating devices, particularly small-scale oxygen generating devices for medical use and gas separation devices.

The device of the present invention will be explained below based on the drawings.

FIG. 1 shows a specific example of the device of the present invention. In the figure,
21 is an air compressor for compressing raw air; 22 is a dehumidifier for removing moisture from the raw air; 23 is a raw air inlet valve; 24 is a compressor for thermally separating high-pressure raw air; It is a vortex tube that generates low-pressure low-temperature air and high-temperature air. 25,
26 is a valve that controls the pressure, flow rate, and flow direction of low-temperature air; 27 is a valve that exhausts the gas adsorbed by the adsorbent; 28 and 29 are valves that control the pressure, flow rate, and flow direction of high-temperature air. The valve 30 is an adsorption column filled with an adsorbent that selectively adsorbs oxygen or nitrogen. Reference numeral 31 denotes a heating heat exchanger used when desorbing oxygen or nitrogen adsorbed by the adsorbent. Inside the heat exchanger 31, high-temperature air generated in the vortex tube 24 flows. 32 is
This is a valve for exhausting high temperature air after heating the adsorbent. 33 is a high temperature air exhaust line. 34 is a valve for controlling the flow of the generated highly concentrated oxygen or nitrogen, 35 is a buffer tank, and 36 is a supply line. valve 26,2
7 is a valve that is also used to exhaust the gas adsorbed on the adsorbent, and 37 is an off-gas line for discarding the exhaust gas. (Usually, the pressure is almost atmospheric.) 38 is an exhaust line for the adsorbed gas.

Next, FIG. 2 shows an outline of the vortex tube. In FIG. 2, a is a longitudinal cross-sectional view, and b is a cross-sectional view taken along the line B-B of a.

In the figure, a straight pipe 10 with a length approximately 10 times the inner diameter
an annular air chamber 12 connected to the air supply pipe 11;
and a plurality of connection holes 13 in which jet ports 14 are bored so as to communicate with the inner wall of the straight pipe 10 in a substantially tangential direction, and one end of the straight pipe 10 is provided with a plurality of connecting holes 13 bored in the center of the pipe. There is an orifice 15, and at the other end,
A valve 16 is provided which is open only at the outer circumference of the pipe cross section. In this vortex tube, first, compressed air is sent from the air supply pipe 11 to the air chamber 12, passes through the connecting hole 13, and is injected into the pipe from the jet port 14 along the inner wall of the straight pipe 10. The injected air becomes a high-speed swirling flow 17 in the pipe, is pressed against the pipe wall by centrifugal force, is adiabatically compressed, and is then taken out from the valve 16 as a flow 18 as indicated by the arrow. On the other hand, the air in the center of the straight pipe 10 expands adiabatically, becomes lower in temperature, and can be taken out from the orifice 15 as shown by the arrow 19.

(Function) In the case of an oxygen generator, the adsorption cylinder 30 performs the adsorption process,
The case where the desorption process is subsequently performed will be described below. The adsorption column 30 alternately repeats the adsorption process and the desorption process, so that oxygen can be generated intermittently,
Furthermore, by increasing the capacity of the buffer tank 35, oxygen can be continuously supplied. In the adsorption step of the adsorption column 30, high-pressure feed air that has passed through the dehumidifier 22 enters the vortex tube 24 through the valve 23 and is separated into relatively low-pressure low-temperature gas and high-temperature gas. The low temperature gas enters the adsorption cylinder 30 through the valve 26, and as a result, most of the nitrogen gas and other gases except for oxygen are adsorbed.
Highly concentrated oxygen gas is obtained from the buffer tank 35 and flows into the buffer tank 35. The reason why highly concentrated oxygen gas is obtained is that the pressure difference between the pressure at the time of desorption of the adsorbent and the low temperature gas and the temperature difference between the temperature at the time of desorption of the adsorbent and the low temperature gas act synergistically. Here, valves 25 and 27 are closed. Further, the high temperature gas generated in the vortex tube 24 passes through the valve 29 and is discharged to the outside through the high temperature air exhaust line 33. Further, the valves 28 and 32 are also closed.

Next, in the desorption process of the adsorption tube 30, the high temperature gas generated in the vortex tube 24 is transferred to the heat exchanger 3.
The desorption effect of the adsorbent is promoted by the heating effect on the adsorbent caused by passing through the gas line 1 and the decrease in the internal pressure of the adsorbent 30 due to the opening of the valves 26 and 27, and the desorption gas is exhausted through the off-gas line 37. be done. At this time, the valve 25 is open and the low temperature gas is discharged to the outside through the exhaust line 38. In addition, the valves 28 and 32 of the high temperature gas line are opened.
Valve 29 is closed, and the high temperature gas that has heated the adsorbent is exhausted through exhaust line 33.

A nitrogen generator can be operated in a similar manner.

(Effects of the invention) Since the device of the present invention utilizes the pressure and temperature differences between the adsorbent and the adsorption/desorption gas, it is possible to increase the adsorption/desorption capacity of the adsorbent. Concentrations of oxygen or nitrogen can be obtained. In addition, since the adsorption/desorption ability based on the temperature difference between the adsorbent and the gas is utilized, the adsorption cylinder filled with the adsorbent can be kept at a low pressure, which makes the device inexpensive and improves safety. Furthermore, since the adsorption capacity is improved, the amount of adsorbent can be reduced, and therefore, the adsorption column, which accounts for a large volume of the entire device, can be made smaller, and the device can be made more compact.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a specific example of an oxygen or nitrogen generating device according to the present invention, and FIG. 2 is a schematic diagram of a vortex tube used in the device of the present invention. FIG. 3 is a schematic diagram of a conventional oxygen or nitrogen generator. Each symbol in the figure is as follows. 1: Air compressor, 2: Adsorption tube, 3, 4, 5: Valve, 6: Buffer tank, 7: Oxygen or nitrogen supply pipe, 8: Off gas piping, 10: Straight pipe, 11: Air supply pipe, 1
2: Air chamber, 13: Connection hole, 14: Spout, 1
5: Orifice, 16: Valve, 17: High-speed swirl flow,
18: Compressed air extraction flow direction, 19: Adiabatic expanded air extraction flow direction, 21: Air compressor, 22: Dehumidifier, 23: Valve, 24: Vortex tube, 25, 26, 27, 28, 29 :
Valve, 30: Adsorption tube, 31: Heat exchanger, 32: Valve,
33: High temperature air exhaust line, 34: Valve, 35: Buffer tank, 36: Supply line, 37: Off gas line, 38: Adsorbed gas exhaust line.

Claims (1)

[Scope of utility model registration request] In an apparatus that generates oxygen or nitrogen using an adsorbent that selectively adsorbs oxygen or nitrogen, an adsorption tube that is connected to a low-temperature outlet of a vortex tube is connected to a high-temperature outlet of the vortex tube through a connecting pipe. An oxygen or nitrogen generator characterized by incorporating a communicating heat exchanger.