JP3151843U - Gas introduction device - Google Patents

Abstract

To provide a gas introduction device having a function capable of inspecting a syringe for gas leakage under substantially the same conditions as in normal operation. A syringe 1 having a bag-like cover 7 made of a soft film that hermetically covers a rear end opening 14 of an outer cylinder 13 and a portion of an inner cylinder 11 protruding therefrom is used. The bag-like cover 7 is provided with a gas inlet / outlet. By expanding the time and observing that the bag-like cover 7 is deflated when a predetermined amount of gas introduced into the bag-like cover 7 leaks through the sliding surfaces of the inner cylinder 11 and the outer cylinder 13. , Know the degree of leakage. [Selection] Figure 1

Description

  The present invention relates to a gas introduction device for introducing a sample gas or the like into a gas analyzer such as an odor identification device.

  A method of introducing a sample gas or the like through a syringe connected to a gas analyzer by piping has been conventionally known (for example, see Patent Document 1). FIG. 3 is a flow chart showing a schematic configuration example of a conventional gas introduction device based on the same principle as this method.

  In the figure, reference numeral 1 denotes a syringe, which has a suction / discharge port 12 at a front end of a hollow cylindrical outer cylinder 13, and an inner cylinder 11 is inserted from a rear end opening 14 and slides on an inner wall surface of the outer cylinder 13. . The inner cylinder 11 is driven by an actuator (not shown) and reciprocates to suck and discharge gas from the suction / discharge port 12. The inlet / outlet port 12 communicates with the gas analyzer 2 through a valve 31, the sample bag 6 through a valve 33, the nitrogen gas cylinder 5 through a valve 34, and the exhaust pump 4 through a valve 32. Communicate.

An example of a procedure for introducing the sample gas from the sample bag 6 into the gas analyzer 2 using the gas introducing device 10 having the above-described configuration will be described below.
(1) With the valves 32 and 34 opened and all the other valves closed, the inner cylinder 11 while releasing nitrogen gas from the nitrogen gas cylinder 5 through the valve 34, valve 32, and exhaust pump 4 in this order to the atmosphere. Is reciprocated several times to clean the inside of the path and the syringe 1 with nitrogen gas.
(2) A required amount of sample gas is drawn from the sample bag 6 into the syringe 1 with the valve 33 opened and all other valves closed.
(3) When diluting the sample gas, in the same state as the above (1), a necessary amount of nitrogen gas is further sucked into the syringe 1 that sucked the sample gas while releasing the nitrogen gas to the atmosphere.
If not diluted, proceed directly to the next (4).
(4) With the valve 31 open and all other valves closed, the inner cylinder 11 is pushed in and the gas in the syringe 1 is discharged toward the gas analyzer 2.

  In order to maintain cleanliness, a medical syringe is proposed in which the rear end opening 14 of the outer cylinder 13 and the portion of the inner cylinder 11 protruding from the outer cylinder 13 are airtightly covered with a bag-like cover made of a soft film. There is an example (see Patent Document 2).

Japanese Patent Laid-Open No. 2005-3387 JP-A-9-313606

When the syringe in the gas introduction device is repeatedly used, gas leakage occurs due to wear, and the amount of gas introduced into the gas analyzer and the dilution rate cannot be accurately measured.
In order to check the leakage of the syringe, the conventional method is to remove the syringe from the gas introduction device and submerge it in water, pressurize it and check with bubbles generated from the syringe, or fill the syringe with helium and inspect with a helium leak detector. However, there are many problems such as the fact that the test results do not match the actual conditions or the preparation of a helium bomb is necessary because the conditions such as pressure are different from those when the syringe is operated in the gas introduction device.

  The present invention has been made in view of such circumstances, and introduces a gas that has a function of being able to inspect a syringe for gas leakage under the same conditions as those given to a syringe during normal operation at a low cost and in a simple manner. An object is to provide an apparatus.

  In order to solve the above problems, the present invention provides a gas introduction device using a syringe having a bag-like cover made of a soft film that hermetically covers both the rear end opening of the outer cylinder and the portion of the inner cylinder protruding therefrom. Configure. By this configuration, the degree of leakage can be increased by observing that the bag-shaped cover is deflated when a predetermined amount of gas previously introduced into the bag-shaped cover leaks through the sliding surface of the inner cylinder, thereby increasing the degree of leakage. It is possible to know, and it is possible to easily determine whether or not the degree of deterioration of the syringe is within an allowable limit.

  Since the present invention is configured as described above, it is possible to perform a syringe leak test under substantially the same conditions as when the gas introducing device is operated, and the reliability of the test results is improved. Thereby, compared with the case where the syringe was replaced early in anticipation of safety in the past, the replacement frequency of the syringe can be reduced, so that the operating cost can be reduced.

It is a figure which shows one Example of this invention. It is a figure which shows the other Example of this invention. It is a figure which shows the conventional structure.

  The device according to the present invention is a gas introduction device configured using a syringe provided with a bag-like cover made of a soft film that hermetically covers a rear end opening of an outer cylinder and a portion of the inner cylinder protruding therefrom. Hereinafter, the best mode for the first embodiment will be described.

  FIG. 1 shows an embodiment of the present invention. In this figure, the same components as those in FIG. 3 are denoted by the same reference numerals as those in FIG. In addition, the procedure for introducing the sample gas into the gas analyzer 2 using the apparatus of this embodiment is the same as that of the conventional apparatus described above.

  The difference between the present embodiment and the conventional configuration shown in FIG. 3 is that a bag-like cover 7 is provided that airtightly covers the rear end opening 14 of the outer cylinder 13 of the syringe 1 and a part of the inner cylinder 11 protruding therefrom. That is. The bag-like cover 7 is made of a film such as polyvinyl, polyethylene, or polyvinylidene that has excellent airtightness and flexibility, and is attached to the outer cylinder 13 in an airtight manner by adhesion, fusion, or fastening. A gas inlet / outlet provided with a valve 35 is provided in a part of the bag-like cover 7, and gas can be introduced / discharged into the bag-like cover 7 through the gas inlet / outlet.

  Since the bag-like cover 7 is rich in flexibility, it can be easily deformed to change its internal volume. If the internal gas is sucked and exhausted, the bag is deflated, the inner volume is almost zero, and the bag material is attached to the outer surface of the syringe 1. Moreover, since it is flexible and lightweight, even when gas is introduced into the bag-like cover 7, the internal pressure is almost equal to the atmospheric pressure.

Next, the concept of the gas leak inspection of the syringe 1 in the above configuration will be described. In addition, the following numerical value is an illustration, Comprising: This invention is not limited to this.
Assuming that the maximum capacity of the syringe 1 is 100 mL and the set value of the suction flow rate when the sample gas is sucked and filled therein is 165 mL / min, the time required for the syringe 1 to suck up to the maximum capacity is 36 seconds. If the allowable amount of gas leaking into the syringe 1 through the sliding surface between the inner wall of the outer cylinder 13 and the inner cylinder 11 during this period, that is, the amount of gas leaking from the bag-like cover 7 is 0.1%, Although the amount is 0.1 mL, it is almost impossible to see even if this amount of gas decreases from the bag-like cover 7, so the leakage amount is enlarged and observed by the following method.

  This gas leakage is a result of the negative pressure in the syringe 1 during suction (determined by the suction flow rate and the flow path resistance of the suction path) acting for 36 seconds, so the same negative pressure is applied for 2 hours (200 times 36 seconds). If allowed to continue, the allowable limit of gas leakage is increased to 20 mL. If this amount of gas decreases from the bag-like cover 7, the bag is deflated and can be easily recognized. In order to apply the same negative pressure as when sucking with the syringe 1 for a long time, the exhaust pump 4 is operated at the same flow rate (165 mL / min) as the suction flow rate of the syringe 1 with the sample bag 6 in FIG. 1 removed. That's fine. Since the suction paths are almost the same, almost the same negative pressure is generated.

In this embodiment, the procedure for actually performing the leakage test of the syringe 1 will be described below.
(1) Disconnect the connection from the valve 33 to the sample bag 6 at the connection with the sample bag 6, reconnect it to the valve 35 as shown by the two-dot chain line, open the valves 32, 33 and 35, and close the other valves. Then, the exhaust pump 4 is operated to exhaust the inside of the bag-like cover 7. When the bag-like cover 7 is completely deflated, the exhaust pump 4 is stopped and the valve 32 is closed. (As another method, air inside the bag-like cover 7 may be sucked out from the valve 35 using another syringe (not shown).)
(2) The connection indicated by the two-dot chain line is disconnected at the connection portion with the valve 35, 20 mL of air is injected from the valve 35 into the bag-like cover 7 using another syringe (not shown), and the valve 35 is closed.

(3) The valves 32 and 33 are opened, the other valves are closed, the exhaust pump 4 is operated, and air is sucked at a predetermined flow rate (for example, 165 mL / min). During this time, an actuator (not shown) is stopped and pressed so that the syringe 1 does not move.
(4) After 2 hours in this state, if air remains in the bag-like cover 7, the syringe 1 is OK. If the bag-like cover 7 is deflated within 2 hours, the syringe 1 is deteriorated and replaced. Is determined to be necessary.

If air remains in the bag-like cover 7 after the process (4) is completed, the degree of leakage can be quantitatively determined by the following method as necessary.
That is, following the process of (4) above, the remaining air inside the bag-like cover 7 is extracted from the valve 35 to another syringe (not shown), and the residual air amount read from this syringe scale is subtracted from the initially injected 20 mL to leak out. You can know the amount of air. Thereby, the deterioration degree of the syringe 1 can be estimated.

  FIG. 2 shows another embodiment of the present invention. In this figure, the same components as those in FIG. 1 or FIG. This embodiment differs from the first embodiment shown in FIG. 1 in that the bag-like cover 7 has no gas inlet / outlet (valve 35), and the end (flange 15) of the inner cylinder 11 of the syringe 1 is a bag-like cover. It is that it has penetrated 7 and went out of it.

  In the first embodiment, the bag-like cover 7 wraps all the protrusions from the rear end opening 14 of the inner cylinder 11 together with the rear end opening 14 of the outer cylinder 13, but the flange 15 is provided with an actuator (not shown) and a machine. Therefore, it is structurally convenient to go out of the bag-like cover 7 as shown in FIG. In this case, it goes without saying that the portion through which the flange 15 penetrates the bag material should be securely fixed by fusion, adhesion or the like in order not to impair the airtightness.

In this embodiment, the procedure for performing a leak test on the syringe 1 is described below.
(1) As shown in FIG. 2, with the inner cylinder 11 of the syringe 1 pulled out of the outer cylinder 13, the valve 32 is opened and the other valves are closed, the exhaust pump 4 is operated, and the bag-like cover 7 When the bag-like cover 7 is completely deflated, the exhaust pump 4 is stopped and the valve 32 is closed.
(2) Remove the sample bag 6 and inject 20 mL of air through the valve 33 using another syringe (not shown). The injected air enters the bag-like cover 7 through the valve 33, the suction / discharge port 12, and the outer cylinder 13, and then the inner cylinder 11 is inserted to an appropriate position in the outer cylinder 13.

(3) The valves 32 and 33 are opened, the other valves are closed, the exhaust pump 4 is operated, and air is sucked at a predetermined flow rate (for example, 165 mL / min). During this time, the actuator (not shown) is stopped and pressed so that the inner cylinder 11 does not move.
(4) After 2 hours in this state, if air remains in the bag-like cover 7, the syringe 1 is OK. If the bag-like cover 7 is deflated within 2 hours, the syringe 1 is deteriorated and replaced. Is determined to be necessary.

  As a modification, a fold-like accordion may be provided in advance on the bag-like cover 7 made of a soft film. Thereby, when the air in the bag-like cover 7 is reduced, the film is folded along the crease, so that an effect of preventing the film from being caught in the sliding portion is obtained.

  The present invention can be used for various gas analyses.

DESCRIPTION OF SYMBOLS 1 Syringe 2 Gas analyzer 4 Exhaust pump 5 Nitrogen gas cylinder 6 Sample bag 7 Bag-shaped cover 10 Gas introduction apparatus 11 Inner cylinder 12 Suction / discharge port 13 Outer cylinder 14 Rear end opening 15 Flange 31 Valve 32 Valve 33 Valve 34 Valve 35 Valve

Claims (2)

  An inner cylinder inserted from the rear end opening of the outer cylinder having a suction / discharge port at the front end includes a syringe that sucks and discharges gas from the suction / discharge port by reciprocating while sliding with the inner wall surface of the outer cylinder. In the gas introduction device for introducing the sample gas into the gas analyzer via the syringe, a bag-like cover is provided that covers both the rear end opening and the portion of the inner cylinder protruding from the rear end opening in an airtight manner. Characteristic gas introduction device.   The gas introduction device according to claim 1, further comprising a gas inlet / outlet for introducing gas into the bag-like cover or discharging gas from the bag-like cover.

Images