JP2599771B2 - Oxygen concentrator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for obtaining oxygen-enriched gas having an increased oxygen concentration from air. In particular, the present invention provides an improved oxygen concentrator that can generate an alarm when filter means for removing dust and the like from intake air in such an apparatus is severely clogged.

[Prior art] Conventionally, oxygen therapy that provides oxygen from an oxygen cylinder to a patient with respiratory disease has been performed. Recently, oxygen therapy using oxygen-enriched gas obtained by concentrating oxygen in the air has been performed. As treatments develop, the treatment is becoming increasingly popular.

As a means for obtaining oxygen-enriched gas from the air, for example, a membrane oxygen concentrator using an oxygen selective permeable membrane,
There is an adsorption-type oxygen concentrator using an adsorbent having different adsorption capacities between oxygen and nitrogen.

In this adsorption-type oxygen concentrator, a compressor or a vacuum pump is used to introduce compressed air into an adsorption bed filled with an adsorbent or to depressurize the inside of the adsorption bed in order to desorb adsorbed components. . In a membrane oxygen concentrator, a vacuum pump is used to maintain a low pressure in a region of a permeated gas in a membrane module using an oxygen selective permeable membrane and to take out an oxygen-enriched gas from the region.

These pump means in such a device involve heat radiation during operation, and a fan means for generating an air flow around the pump means is usually used to remove the heat, and the intake of the air flow has dust or the like. Is provided.

A part of the air after passing through the filter means is introduced into the adsorption bed in the case of the adsorption type oxygen concentrator, and is supplied to the membrane side space of the membrane module in the case of the membrane type oxygen concentrator. .

In such a conventional oxygen concentrator, when the device is used for a long period of time, the filter is periodically replaced with a new one to prevent the filter from being clogged.

However, depending on the operating environment of the device, the filter may become clogged abnormally quickly, and if the operation of the device is continued further in this state, the cooling of the pump means will be insufficient and cause a failure, or the membrane module will be damaged. In some cases, the supply of air to the membrane surface side may be insufficient and predetermined concentration may not be performed. Therefore, it was necessary to perform an excessive maintenance inspection such as replacing the filter earlier than necessary.

[Problems to be Solved by the Invention] The present invention is to solve the problems of the conventional oxygen concentrator. That is, it is an object of the present invention to provide an oxygen concentrator capable of replacing a filter at an appropriate time according to a clogged state of a filter means for removing dust and the like from intake air.

[Means for Solving the Problem] The present inventors have conducted intensive research to solve such problems, and have found a means for detecting a clogged state of a filter means, and a means for detecting a clogged state of a certain level or more in conjunction therewith. It has been found that it is effective to provide a means for generating an alarm in the event that this happens, and the present invention has been reached.

In particular, as a simple means for detecting the clogged state of the filter, it has been found that the temperature detection means on the upstream and downstream sides of the cooling air flow flowing around the pump means is very effective, and the present invention has been made. It has been reached.

It has also been found that the problem can be effectively solved by using a fine differential pressure gauge for detecting the difference between the respective static pressures on the upstream side and the downstream side of the filter means.

That is, the present invention provides oxygen concentrating means for obtaining oxygen-enriched gas from air, pump means connected to the oxygen concentrating means by conduit means, and a fan for generating an air flow for cooling the pump means. The means is housed in outer shell means, wherein the outer shell means has an air inlet, an air outlet, and oxygen-concentrated gas deriving means, and the air inlet has a filter means. Provided is an oxygen concentrating device, comprising: clogging detecting means for detecting a clogging state; and alarm generating means for generating an alarm in a predetermined clogging state in conjunction with the detecting means. Things.

According to the apparatus of the present invention, the outer shell means forming the box contains the oxygen concentrating means, the pump means and the fan means. Further, if necessary, conduit means and other things are housed together.

Further, the apparatus of the present invention is provided with an outlet of an air inlet and a means for extracting oxygen-enriched gas in its outer shell means, and further includes a filter means for removing dust and the like of the intake air. is there.

As an adsorption type oxygen concentrator as a preferred embodiment of such an oxygen concentrator, for example, a pressure fluctuation adsorption type (hereinafter sometimes abbreviated as PSA type) is used, which selectively adsorbs oxygen or nitrogen. After pressurized air is supplied to the adsorbent bed filled with the adsorbent to selectively adsorb specific components, the pressure of the adsorbent bed is reduced and desorption is performed to remove the gas having an increased oxygen concentration. Device to obtain. Such an oxygen concentrator comprises an adsorbent bed, a compressor driven by an electric conductor, a fan means for generating an air flow for cooling the compressor driven by the electric conductor, and connecting the adsorbent bed and the compressor. The main components are conduit means for allowing compressed air to flow into the adsorption bed and automatic valve means provided therein for controlling pressure fluctuations in adsorption and desorption. Here, the number of adsorption beds may be one or two or more, but in the case of a small-sized oxygen concentrator for medical use, the number is preferably three or less, and particularly preferably one or two. A compressor is usually used as the compressed air supply means, but may be a blower type in some cases. As the fan means, it is preferable to use another fan means in addition to the fan usually attached to the compression means itself, since the cooling of the compression means and the like can be surely performed.

In addition, as a membrane-type oxygen concentrator according to another preferred embodiment, for example, a large number of membrane elements are stacked with an external spacer interposed between membrane elements to provide a flow path through which air can flow on the membrane surface. Air is taken in from the outside of the arranged membrane module and the membrane element in the membrane module, and the air is supplied to the outside space of the membrane element to allow the air to pass through the membrane surface, and the used air having a reduced oxygen concentration is discharged out of the apparatus. Fan means, vacuum means for maintaining the inside space of the membrane element under reduced pressure, allowing oxygen-enriched air to permeate the membrane, and removing the oxygen-enriched air from the inside of the element, and collecting oxygen-enriched air from within each element. One having a conduit means for flowing to the means for discharging oxygen-enriched air in the outer shell of the apparatus.

As an example of a particularly preferred embodiment of the filter clogging detecting means which is a feature of the apparatus of the present invention, an upstream temperature and a downstream temperature of an air flow for cooling a pump means such as a compressor or a vacuum pump. means for detecting a means for comparing the temperature T ₂ of the temperature T ₁ of the downstream side of the detected upstream thereof.

Specific examples of such a temperature detecting means include a thermocouple type in which a temperature-sensitive portion is positioned in each of the upstream and downstream air flows, and a platinum resistor type. Specific examples of the comparison means also T ₁ and T _2, and a method of forming a bridge circuit for temperature difference measurement can be given with two thermocouples method or resistance thermometer See difference electromotive force by comparing the .

In yet another example embodiment of filter clogging detecting means, the downstream side of the air flow of the atmospheric pressure P ₁ and the filter static pressure
Means for detecting the differential pressure of P ₂ (P ₁ −P ₂ ) can be mentioned. As a specific example of such a differential pressure detecting means, there is a diaphragm type differential pressure gauge.

Further, as a specific example of the alarm generating means interlocked with the filter clogging detecting means which is a feature of the apparatus of the present invention, when the clogging detecting means is the above-described temperature detecting means, the temperature difference (T ₂ −T ₁ ) Raises an alarm if the value is equal to or more than a predetermined value, and the clogging detection means uses a differential pressure (P ₁ -P ₂ )
If the differential pressure (P ₁ −P ₂ ) is equal to or more than a predetermined value, an alarm is issued. Preferred values of the predetermined values for the temperature difference (T ₂ −T ₁ ) and the pressure difference (P ₁ −P ₂ ) depend on the flow rate of the air flow required for cooling the pump means and the degree of opening of the filter means. Differently, it can be set appropriately. For example, when the temperature detecting means is used, the temperature difference (T ₂ −T ₁ ) when no foreign matter is attached to the filter is set as a reference value, and the temperature difference when foreign matter is attached to the filter and clogging occurs ( T ₂ −T ₁ ) is more than about 5 ° C.
In some cases, an alarm is issued if the temperature is about 3 ° C. or more.

As a specific example of the alarm generating means itself,
Examples include a warning lamp type and a sound generation type such as a buzzer for warning.

The filter means in the apparatus of the present invention is not particularly limited, and examples thereof include a porous body having an interconnected void such as a sponge-like one or a fiber aggregate. Also, a plurality of filter means may be used in a stacked state or in series, and an electrostatic filter or a filter having an adsorbing ability may be used for some of the filters. As the shape of the filter means, usually, a flat shape is used, but it is more preferable to make the shape of a waveform or the like in order to increase the effective area.

INDUSTRIAL APPLICABILITY The oxygen concentrator of the present invention is advantageously used for applications requiring oxygen-concentrated gas, and in particular, optimizes the filter replacement time as a medical oxygen concentrator used in homes with various dust generation situations. It is useful as an improved device.

[Effect of the Invention] The oxygen concentrating device of the present invention has an excellent effect that it is possible to easily determine an appropriate replacement time of a filter means for removing dust and the like in the air taken into the device. Therefore, there is an advantage that the filter replacement time does not need to be advanced earlier than necessary, and the occurrence of trouble due to the clogging can be reliably prevented even in an environment where clogging of the filter is abnormally fast.

Claims (4)

(57) [Claims] 1. An oxygen concentrating means for obtaining an oxygen-enriched gas from air, a pump means connected to the oxygen concentrating means by a conduit means, and a fan for generating an air flow for cooling the pump means. The means is housed in outer shell means, wherein the outer shell means has an air inlet, an air outlet, and oxygen-concentrated gas deriving means, and the air inlet has a filter means. Temperature detecting means for detecting an upstream temperature and a downstream temperature of an air flow passing around the pump means in order to detect a clogging state; an upstream temperature T1 and a downstream temperature detected by the temperature detecting means; Means for comparing the side temperature T2, and
An oxygen concentrator comprising an alarm generating means for generating an alarm when T2 is higher than T1 by a predetermined value or more. 2. The oxygen concentrator according to claim 1, wherein an alarm is issued when the difference between T1 and T2 is 3 ° C. or more. 3. The oxygen concentrating means is one or more adsorbent beds packed with an adsorbent capable of selectively adsorbing nitrogen or oxygen, and the pump means compresses air into the adsorbent beds. 2. The oxygen concentrator according to claim 1, wherein the oxygen concentrator has a function of introducing under pressure and / or a function of extracting gas adsorbed on the adsorption bed under reduced pressure. 4. A vacuum pump, wherein said oxygen concentrating means comprises an oxygen selective permeable membrane, and said pump means reduces the pressure on one side of said oxygen selective permeable membrane to extract the permeated oxygen concentrated gas. The oxygen concentrator according to claim 1, which is a means.