JPH0433942Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Field of Industrial Application) The present invention relates to a small-sized oxygen generator that supplies oxygen by adsorbing nitrogen in the air to zeolite. (Conventional technology) The amount of oxygen used in medical oxygen inhalation ranges from a few centimeters to a dozen centimeters per minute, and in most cases oxygen from high-pressure oxygen cylinders is used at reduced pressure. need to be prepared. In addition, recently, oxygen generators have been commercially available that use zeolite as an adsorbent to adsorb nitrogen in the air to obtain oxygen. By the way, when separating oxygen from the air using the pressure swing adsorption method, oxygen is collected by adsorbing nitrogen onto an adsorbent under pressure, and the adsorbed nitrogen is desorbed and exhausted under reduced pressure. ,
The adsorbent is regenerated in preparation for the next pressurized adsorption. At this time, if the desorption and elimination of nitrogen is incomplete, some of the nitrogen remaining in the adsorption column containing the adsorbent will mix with the product oxygen in the next pressurized adsorption step, causing the product to become oxygenated. Decrease concentration. Generally, 70
% or more, it is necessary to eliminate residual nitrogen in the adsorption tower as much as possible.To do this, a part of the product oxygen is flowed back into the adsorption tower using an oxygen backflow method, or an adsorption tower It is necessary to forcefully evacuate the inside using a vacuum evacuation method. (Problems to be Solved by the Invention) The conventional vacuum evacuation method requires a vacuum pump and an accompanying control mechanism such as an automatic valve, and there are also problems such as noise generated by the vacuum pump. The oxygen backflow system requires a gas holder that accommodates the separated oxygen product and a complicated valve mechanism between the holder and the adsorption tower. The above circumstances have prevented the reduction in noise, size, weight, and cost of oxygen generators using the pressure swing adsorption method. (Means for Solving the Problems) The present invention has been made in view of the above circumstances, and its configuration is as follows. In an oxygen generator using an adsorption tower filled with zeolite having nitrogen adsorption properties, one end side of the first adsorption tower and the second adsorption tower is connected to an air supply pipe equipped with an air supply valve that opens and closes alternately. The first adsorption tower and the second adsorption tower
At the other end of the adsorption tower, a check relief valve for oxygen collection and a check relief valve for oxygen backflow that operate at a set pressure slightly lower than the set pressure of the valve are provided, respectively.
This is an oxygen generator in which both adsorption towers are connected to each other through a communication gas holder connected to an oxygen gas supply pipe. (Function) The oil-free compressor is operated to supply air from the air supply pipe to the first adsorption tower or the second adsorption tower via the air supply valve that opens and closes alternately. At this time, among the exhaust valves that are alternately opened and closed, the exhaust valve of the adsorption tower to which air is not supplied is opened. By doing this, if air is being supplied to the first adsorption tower, for example, the pressure inside the first adsorption tower will rise, and the pressure inside the adsorption tower will rise at the set pressure of the oxygen collection check relief valve. The zeolite adsorbs nitrogen, and the separated oxygen gas is sent into a communicating gas holder. In addition, in the second adsorption tower to which air is not supplied, the check relief valve for oxygen backflow opens at a set pressure slightly lower than the set pressure of the collection check relief valve, and some of the oxygen causing the gas to flow back into the adsorption tower;
Residual nitrogen in the adsorption tower is replaced by oxygen gas and discharged to the exhaust pipe via the exhaust valve to perform the regeneration process. During this time, the oxygen gas in the communication gas holder is taken out from the oxygen gas supply pipe and used. Then, the first adsorption tower and the second adsorption tower alternately repeat the nitrogen adsorption step and the regeneration step to separate and utilize the oxygen gas. (Example) An example of the oxygen generator according to the present invention will be described based on the drawings. In the figure, 1 is the first adsorption tower and 2 is the second adsorption tower.
It is an adsorption tower. Both columns 1 and 2 are filled with zeolite having nitrogen adsorption properties. Reference numeral 3 designates a communicating gas holder that communicates with both adsorption towers 1 and 2, respectively, and stores oxygen gas as a product. 4 is an oil-free compressor, and an air supply pipe L 1 is connected to gas supply and exhaust pipes 1a and 2a provided at one end of both adsorption towers 1 and 2 via first and second air supply valves 1b and _2b , respectively. It is connected at. Further, both gas supply and exhaust pipes 1a and 2a are connected to an exhaust pipe _L2 through first and second exhaust valves 1c and 2c, respectively. And each valve 1b, 1
c, 2b, and 2c are mutually controlled by a timer or the like in each step as shown in the table.

[Table] Between both the adsorption towers 1 and 2 and the communicating gas holder 3, there are two oxygen collecting check relief valves 1d which are in the open position at constant pressure from both the adsorption towers 1 and 2 to the communicating gas holder 3.
2d and communicating gas holder 3 to both adsorption towers 1 and 2.
to the open position with constant pressure, and both check relief valves 1d,
Pressure slightly lower than the set pressure of 2d (0.2~0.5
Check relief valves 1e and 2e for backflow of oxygen are provided, which are set at a low pressure of Kg/cm ² G (low pressure side). L ₃ is an oxygen gas supply pipe connected to the communication gas holder 3 and supplies oxygen gas as a product to the outside, and 5 is a throttle valve. Next, the effect will be explained. If the oil-free compressor 4 is operated with the first air supply valve 1b opened, the first exhaust valve 1c closed, the second air supply valve 2b closed, and the second exhaust valve 2c opened, air will flow to the first adsorption column. The air pressure inside the first adsorption tower 1 rises and the zeolite inside the first adsorption tower 1 begins to adsorb nitrogen. When the zeolite in the first adsorption tower 1 adsorbs nitrogen and the pressure inside the tower 1 reaches the set pressure of the oxygen collection check relief valve 1d, the valve 1d assumes the open position and oxygen gas is communicated. Collected into holder 3.
The pressure inside the communication holder 3 is reduced to the oxygen collection check relief valve 1.
When the pressure reaches a pressure slightly lower than the set pressure of d and 2d, the oxygen in the communication gas holder 3 passes through the check relief valve 2e for oxygen backflow into the second adsorption tower 2, where the second exhaust valve 2c is opened. A portion of the gas is delivered and the second
The residual nitrogen in the adsorption tower 2 is replaced by oxygen gas and is discharged from the second exhaust valve 2c to the exhaust pipe _L2 ,
Zeolite is regenerated. Also, during this time, the oxygen gas in the communication gas holder 3 is transferred to the oxygen gas supply pipe L ₃
The air is then depressurized by the throttle valve 5 and supplied to the outside. When the zeolite in the first adsorption tower 1 has sufficiently adsorbed nitrogen, each valve 1b, 1c, 2b, 2c is switched by a timer or the like. That is, the first air supply valve 1b and the second exhaust valve 2c are closed, and the second air supply valve 2b and the first exhaust valve 1 are closed.
Let c be open. Thus, the air from the oil-free compressor 4 is sent to the second adsorption tower 2, and the zeolite in the second adsorption tower adsorbs nitrogen, while the air from the first adsorption tower 1
The nitrogen adsorbed inside is released from the first exhaust valve 1c. If the pressure inside the column 2 becomes higher than the set pressure of the oxygen collecting check relief valve 2d, the column 2
The oxygen gas inside is sent into the passing gas holder 3, and when the oxygen gas pressure inside the communication gas holder 3 reaches a predetermined pressure that is slightly lower than the set pressure of the oxygen collection check relief valves 1d and 2d, oxygen backflow occurs. The first exhaust valve 1c opens and a part of the oxygen gas in the communication gas holder 3 is released into the exhaust pipe.
Air is sent into the first adsorption tower 1 connected to L ₂ ,
The residual nitrogen in the first adsorption tower 1 is replaced by oxygen gas and is discharged from the first exhaust valve 1c to the exhaust pipe _L2 . As described above, adsorption and regeneration of nitrogen are alternately repeated in the first adsorption tower 1 and the second adsorption tower 2, and the oxygen gas separated during this is utilized. In addition, in the regeneration process of zeolite in the adsorption tower, at the stage of pressure drop due to the release of nitrogen gas in the adsorption tower, the temperature inside the adsorption tower during regeneration decreases, which prevents the desorption of nitrogen. The temperature of the oxygen gas that later enters the adsorption tower increases during the pressure adsorption process, and as this oxygen gas is fed into the adsorption tower, the temperature inside the adsorption tower increases. It is possible to prevent a temperature drop and facilitate the desorption of nitrogen. (Effects of the invention) As understood from the above explanation, the invention provides the following effects. (a) By communicating two adsorption towers with a communication gas holder, oxygen gas can be obtained continuously and stably by controlling two air supply valves and two exhaust valves,
The structure of the oxygen generator is simplified. (b) The heat generated in the pressurized adsorption step is used to suppress the temperature drop during reduced pressure regeneration, effectively promoting zeolite regeneration. (c) Oxygen gas removal during the adsorption process and oxygen gas supply during the regeneration process are automatically performed without external control using two check relief valves for oxygen collection and two check relief valves for oxygen backflow. It is done with purpose. (d) By connecting two adsorption towers with a communicating gas holder, the oxygen generator can be made smaller. (e) Since the direction of inflow of oxygen gas from the communication holder to the adsorption tower can be completely opposite to the direction of outflow from the adsorption tower, the air in the adsorption tower can be scavenged effectively.

[Brief explanation of drawings]

The figure is a schematic diagram showing an embodiment of the oxygen generating device according to the present invention. 1...first adsorption tower, 1b...first air supply valve,
1c...First exhaust valve, 1d, 2d...Check relief valve for oxygen collection, 1e, 2e...Check relief valve for oxygen backflow, 2...Second adsorption tower, 2b...Second air supply Valve, 2c...Second exhaust valve, 2...Communication holder, 4
...Oil-free compressor, 5... Throttle valve, L ₁ ... Air supply pipe, L ₂ ... Exhaust pipe, L ₃ ... Oxygen gas supply pipe.

Claims (1)

[Scope of utility model registration request] In an oxygen generator using an adsorption tower filled with zeolite having nitrogen adsorption properties, one end side of the first adsorption tower and the second adsorption tower are connected to each other by an air supply pipe equipped with an air supply valve that opens and closes alternately. The first adsorption tower and the second adsorption tower
On the other end side of the adsorption tower, a check relief valve for oxygen collection and a check relief valve for oxygen backflow that operate at a set pressure slightly lower than the set pressure of the valve are provided, respectively.
An oxygen generator characterized in that both adsorption towers are communicated with each other through a communication gas holder connected to an oxygen gas supply pipe.