JPH0678927B2 - Flowmeter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a flow meter having a specific structure. More specifically, the present invention provides an improved flow meter that is easy to manufacture and easy to operate when adjusting the flow rate, and is stable and easy to operate, especially for medical use and other respiratory improvement or reinforcement. The present invention provides a flow meter suitable for a device capable of supplying an oxygen-enriched gas.

<Prior Art> Oxygen therapy for supplying oxygen from an oxygen cylinder has been conventionally performed for patients with respiratory diseases, and recently oxygen-enriched air obtained by concentrating oxygen in the air was used. With the development of oxygen therapy, its treatment methods have become increasingly popular. With these oxygen therapies,
When supplying a gas such as oxygen or oxygen-enriched air to the nasal cavity of a patient, it is necessary to adjust the flow rate to a predetermined value.

In addition to such medical applications, there are many demands for controlling the flow rate of gas such as air, nitrogen, etc., such as supply of industrial gas raw materials and aeration for fermentation, wastewater treatment, etc., and controlling the flow rate of liquids. There are many requests.

Generally, the flowmeter is selected by taking advantage of its characteristics such as differential pressure type, hot wire type, ultrasonic type, area type, vortex type, etc., depending on its primary pressure, flow rate range, and fluid conditions. There is an automatic flow controller that is controlled in an orthodox way.

As another method, there is a manual method that moves the control valve by hand while measuring the flow rate. For the flow rate measurement, the one using the above-mentioned measuring instrument or the one using the rotor meter for the simpler one is used It is usually implemented using the control valve of.

Since the former automatic flow rate control device is inevitably expensive in price, the latter is cheaper, and when it is used for a product for personal consumption, the former is not applicable from an economical point of view. For that reason, the latter manual method is often adopted, but it can be said that the rotor meter is rather unsuitable for general consumers because the setting of the rotor meter is troublesome and the flow rate reading is difficult.

In other words, the main demand for this from general consumers is
There are two points: it is easy to see the flow rate display, it is a digital type, and the flow rate can be set with one touch.

<Object of the Invention> An object of the present invention is to provide an improved flow meter that meets the demands of general consumers and the like and is suitable for an oxygen-enriched gas supply device. Further, the object of the present invention is to
It is an object to provide a flow meter that is easy to manufacture, has good reproducibility, and can easily set and read the flow rate even during use.

<Structure of the Invention> As a result of earnest research to achieve such an object, the present inventors have found that a thin plate-like object provided with a through hole by a method that is easy to manufacture by mass production such as etching and has a high processing accuracy. The inventors have found that it is very effective to set the flow rate by using the method and arrived at the present invention.

That is, the present invention provides a plate-like member having a thickness of 0.01 to 1 mm having a fluid inlet, a fluid outlet, and a plurality of independent through holes each having a different flow resistance when the fluid passes, and the fluid The flow path throttle adjusting means is provided on the inlet side, and the plate-shaped member is attached to a support having a hole penetrating at least a portion corresponding to the through-hole, and the plate-shaped member together with the support. By rotating the fluid, the fluid inlet and the fluid outlet are communicated with each other through the through hole, the fluid is circulated through the through hole, and the flow rate of the fluid corresponding to the through hole is displayed. The present invention provides a flowmeter characterized by adjusting and displaying a flow rate.

In addition, a means for generating an oxygen-enriched gas having an oxygen concentration higher than that of air, a supply means for using the oxygen-enriched gas for use, and a flow meter for adjusting the flow rate of the oxygen-enriched gas are provided. In the above oxygen-enriched gas supply device, the flow meter includes a thin plate member having an inflow port for the oxygen-enriched gas, an outflow port for the gas, and a plurality of independent through-holes. An oxygen-enriched gas supply device, characterized in that the flow rate of the gas is adjusted by circulating the gas; and a means for generating an oxygen-enriched gas having an oxygen concentration higher than that of air; An oxygen-enriched gas supply device comprising a supply means for supplying a enriched gas for use, and a flow meter for adjusting the flow rate of the oxygen-enriched gas, wherein the flow meter comprises an inlet for the oxygen-enriched gas, The gas outlet, a portion having a plurality of independent through holes And the gas flow rate span adjusting means provided in the gas inlet or conduit means connected thereto, and the gas flow rate is adjusted by causing the gas to flow through the through hole. The characteristic oxygen-enriched gas supply device is given as a reference.

The present invention will be described in more detail below with reference to the drawings.

FIG. 1 shows a preferred embodiment of the gas flow meter of the present invention.
An example is shown in a sectional view. That is, the flow meter in the figure is
A rotatable switching main shaft 2 is mounted in a main body housing 1, and a cylindrical chamber structure 3 is provided on the switching main shaft, and a cylindrical circumferential portion (that is, a support for a thin plate member 4). 5 has a plurality of relatively large holes 6. Further, a thin stainless steel (SUS) plate (that is, a thin plate member) 4 having a large number of independent through holes 7 having different hole diameters provided by etching or the like on the inner surface of the circumferential portion 5 is fitted. There is. In the SUS plate, each through hole is located at a position corresponding to each hole 6 in the circumferential portion 5, and at least the SUS plate is kept so as to maintain airtightness around the hole 6 in the circumferential portion.
It is desirable that the plate 4 be attached to the surface of the circumferential portion 5 in close contact or adhesion. As a method of fixing the SUS plate 4, a ring of polytetrafluoroethylene or the like may be inserted inside. Further, it is desirable to provide packing members 8 and 9 so as to maintain airtightness between the main body housing 1 and the switching main shaft 2. In such a gas flow meter, the gas is introduced from the gas inlet 10, passes through the selected through hole 7 of the SUS plate 4 and the corresponding hole 6 in the circumferential portion, and flows out from the gas outlet 11. As a result, the gas adjusted to the flow rate of the gas corresponding to the hole diameter of the through hole 7 flows out to the outflow port 11. If the switching spindle 2 is rotated to select another through hole 7 and the flow rate corresponding to each through hole 7 is digitally displayed on the disk member 15, the switching spindle can be changed to a predetermined position with one touch. The flow rate displayed on the digital display can be adjusted to enable extremely simple operation. The digital display is LED
There are types such as an attached display board and a rotary encoder that is attached to the shaft to recognize the angle rotated by a pulse and display it digitally.

Further, by installing the variable throttle means 12 at the gas inlet, the flow rate range can be variably adjusted and the flow rate to the through hole 7 can be adjusted. With the through hole 7 on the SUS plate and the throttle means 12 for adjusting the primary pressure, it is possible to manufacture and realize a flow meter of any range with high accuracy and high reproducibility. The throttling means 12 in the figure is for adjusting the flow rate resistance of the fluid flowing in from the inflow port 10 by screwing in and out its position in the axial direction of the hole.

Further, by using such a primary pressure adjusting diaphragm means, it is possible to adjust a flow meter using a plurality of through holes provided in a member that is not necessarily a thin plate member.

Therefore, it is possible to provide a switchable flow meter with much more freedom by processing through holes on the SUS plate and attaching various types of through holes in advance.Since it can be provided easily and inexpensively, its merits are measurable. Absent. Note that FIG. 1 shows 1
It is needless to say that the gas flowmeter of the present invention includes other examples, which are merely examples of embodiments.

Also, FIG. 2 has a plurality of independent through holes 7 which can be incorporated into the gas flow meter illustrated in FIG.
Although the plate member 4 having a small thickness of mm is shown, the flow meter of the present invention may have other shapes.

The material of the plate-shaped member in the present invention is not particularly limited, and can be selected in consideration of mechanical strength, corrosion resistance and the like according to the purpose of use. In the case of a flow meter for an oxygen-enriched gas supply device described later, stainless steel, which is hard to be oxidized and has appropriate mechanical strength, is most preferable, but other metals such as copper and plastics may be used. it can.

The thickness of the thin plate member of the present invention, 10 ~ 1000μ
Furthermore, 10 to 300 μm, and particularly 20 to 150 μm are particularly desirable because the mechanical strength is maintained appropriately and processing such as etching can be easily performed with good reproducibility.

Further, the shape of the plate-like member is not particularly limited, but a disk-like shape, a belt-like shape or the like is preferable, and the second shape is particularly preferable.
The belt shape shown in the drawing is practically desirable because it can secure an area for providing a large number of through holes and can make the whole compact. Regarding the size of the plurality of through holes, the flow resistance or the pressure loss when the gas passes may be the same or different, but in practice, the different flow resistance ranges can cover a wider flow range. Also, the use of large holes is preferable because it is easy to prevent clogging. The shape of the through hole may be any shape, but it is preferable that the circumference has a rounded shape. Particularly, if the shape is close to a substantially perfect circle, the fluid flow state is more likely to be stable and reproducibility during manufacturing is improved. Good.

Any method may be used to create such through holes, but in the case of a thin plate member, etching processing, etching processing by photochemical reaction, etc. are preferable.

It is desirable that the thin plate member be attached to a support member provided with a hole larger than the through hole at a corresponding position so as to rotate together with the support member.
In that case, the thin plate member may be attached to the upstream side of the flow of the fluid, and the airtightness between the thin plate member and the main body housing may be maintained by a packing member or the like on the support surface on the opposite side of the plate member. It is effective in preventing clogging of the penetration part.

Further, as a mechanism for switching the switching main shaft, for example, it is effective that a part of the switching main shaft has a polygonal cross-sectional shape and a notching steel ball 16 is combined to make the switching angle constant and securely fixed at a predetermined position. Is. The switching main shaft may be rotated manually or may be electrically rotated by attaching a drive motor to the shaft.

The oxygen-enriched gas supply device of the present invention has, in addition to the oxygen-enriched gas generating means and the supply means for using the oxygen-enriched gas, a flow meter for adjusting the flow rate of the oxygen-enriched gas as described above. It is equipped with a flow meter. The oxygen-enriched gas generating means is a means for generating oxygen-enriched air having an oxygen concentration higher than that of air, or a gas mainly composed of oxygen. Specific examples thereof include an oxygen enricher for obtaining oxygen-enriched air from the air, such as an adsorption-type oxygen enricher or a membrane-type oxygen enricher.
1 such as means for obtaining oxygen gas from oxygen cylinders and liquid oxygen
Examples include those using seeds and those using combinations thereof. As described above, the oxygen-enriched gas referred to in the present invention means oxygen-enriched air, oxygen gas, or the like.

As a specific example of the adsorption-type oxygen enricher, which is one of the preferable embodiments of the present invention, one or two or more adsorbent beds filled with an adsorbent that selectively adsorbs nitrogen gas are used. A compressor means for introducing pressurized air into the bed, and an enrichment conduit means for extracting oxygen-enriched air from the adsorbent bed and flowing it to the outlet, one unit or Examples of the enricher include two adsorbent beds which are operated so as to repeat one cycle of pressurization-depressurization or alternately. The specific structure of a membrane-type oxygen enricher, which is another preferred embodiment of the oxygen enricher of the present invention, is illustrated below. That is, as the enricher, a fan means for taking in the atmosphere, a module composed of a large number of membrane cells configured so that the atmosphere permeates the surface of the gas-selective permeable membrane and oxygen-enriched air permeates the membrane. Vacuum pump means for keeping the pressure on the back side of the membrane in the cell lower than atmospheric pressure, and for taking out oxygen-enriched air from the module, and an enricher for circulating the taken-out oxygen-enriched air to the outlet of the enricher. One having an inner conduit means is included. Among these generating means, the adsorption type oxygen enricher is most suitable for the oxygen enriched gas supply device of the present invention.

The oxygen-enriched gas supply device of the present invention comprises such an oxygen-enriched gas generating means, a supply means for supplying the oxygen-enriched gas without using the enriched gas, and a flow meter of the enriched gas of the type described above. It is a thing. The supply means may be of any type, and specific examples thereof include a nasal cannula type and a mask type in which the tip of a thin tube is inserted into the nasal cavity. In some cases, it may be a conduit means such as a simple tube. Regarding the flow rate of the oxygen-enriched gas supplied from the supply means, when an oxygen-enricher is used as the generation means, the lower limit is preferably 0.1 / min, more preferably 0.5 / min, and especially 1 / min. , And the upper limit is 10
/ min, more preferably 8 / min, especially 6 / min.

In the oxygen-enriched gas supply device according to the present invention, when the gas generating means generates an enriched gas pressurized more than necessary, a depressurizing means is provided between the generating means and the flow meter. It is desirable to provide it. Particularly when a pressure fluctuation adsorption type oxygen enricher is used, the pressure on the inlet side of the flow meter is likely to fluctuate, so it is desirable to provide two decompression means in series on the upstream conduit means. . Further, it is preferable to provide a filter means on the upstream side of the conduit means connected to the gas inlet of the flow meter, particularly preferably on the upstream side thereof, in order to prevent clogging of the through hole in the flow meter. As such a filter means, a sterilization filter may be used, which also has a function of preventing the invasion of bacteria.

<Effects of the Invention> With the flowmeter of the present invention, a highly accurate flowmeter with a simple manufacturing method and sufficient reproducibility can be easily obtained, and when the flowmeter is used, the flow rate can be easily set by, for example, one-touch operation. There is an advantage that it can be performed and the display of the flow rate can be a digital type that is easy to visually confirm. Further, the flowmeter of the present invention has an advantage that clogging is less likely to occur and high reproducibility of the flow rate can be obtained because the thickness of the member of the through hole having the narrowed flow passage is thin.

Further, the oxygen-enriched gas supply device of the present invention, by incorporating the flow meter having the above advantages, it is possible to switch the flow rate by a simple operation of one-touch type, and the flow rate display can be made into a cheap digital format, Furthermore, there is an advantage that troubles caused by the flow meter can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an embodiment of the gas flowmeter of the present invention, and FIG. 2 shows a thin plate member having a large number of through holes used for the flowmeter. It is an example.

Claims (2)

[Claims] 1. A plate-shaped member having a thickness of 0.01 to 1 mm, having a fluid inlet, a fluid outlet, and a plurality of independent through holes each having different flow resistance when the fluid passes, and a plate-shaped member of the fluid. A flow path throttle adjusting means is provided on the inlet side, and the plate-shaped member is
The plate-shaped member is attached to a support having a hole penetrating at least a portion corresponding to the through hole, and the plate-shaped member is rotated together with the support so that the fluid inlet and the fluid flow through the through hole. A flowmeter, characterized in that the outlet is communicated to allow the fluid to flow through the through hole, and the flow rate of the fluid corresponding to the through hole is displayed to thereby adjust and display the flow rate of the fluid. 2. The flowmeter according to claim 1, wherein the through hole is provided by processing the plate member by etching.