JP6408502B2 - Gas sampling container - Google Patents

Description

  The present invention relates to a gas sampling container, and more particularly to a gas sampling container for sampling by vaporizing a low-temperature liquefied gas.

  The quality inspection of low-temperature liquefied gas such as liquefied oxygen, liquefied nitrogen, liquefied argon, and liquefied natural gas is performed by analyzing a gas obtained by vaporizing the low-temperature liquefied gas. As means for vaporizing and sampling the low-temperature liquefied gas, a vaporizer that introduces and vaporizes the low-temperature liquefied gas to be sampled into the heat transfer tube, and a sampling cylinder that introduces and stores the gas vaporized by the vaporizer. A gasification sampling device for low-temperature liquefied gas provided is known (for example, see Patent Document 1).

Japanese Utility Model Publication No. 1-120647

  However, the sampling device described in Patent Document 1 has a problem in that the configuration of the vaporizer is complicated and sampling cannot be performed with high accuracy.

  Accordingly, an object of the present invention is to provide a gas sampling container that can efficiently sample a gas obtained by vaporizing a low-temperature liquefied gas with a simple configuration.

  In order to achieve the above object, the gas sampling container of the present invention is a gas sampling container having an inlet valve at one end of a cylindrical container and an outlet valve at the other end, and a sintered metal filter is provided downstream of the inlet valve. It is characterized by providing.

  Furthermore, in the gas sampling container of the present invention, the inlet valve is a dual three-way valve in which a purge valve and an introduction valve are integrated, and the sintered metal filter is provided integrally with the inlet valve. It is characterized by having.

  According to the gas sampling container of the present invention, when the low-temperature liquefied gas passes through the sintered metal filter, it becomes droplets that are subdivided into a size of several μm or less, and thus flows into the cylindrical container. It vaporizes quickly and is stored in a container. Therefore, the gas obtained by vaporizing the low-temperature liquefied gas can be sampled in the container with a very simple apparatus configuration without providing a vaporizer equipped with a heat transfer tube or a heating means. Further, since the gas after vaporization is stored in the container as it is, the impurities contained in the low-temperature liquefied gas can be reliably held in the container.

It is explanatory drawing which shows one example of the low temperature liquefied gas sampling apparatus which uses the gas sampling container of this invention.

  FIG. 1 shows an example of a low temperature liquefied gas sampling apparatus using the gas sampling container of the present invention. First, the gas sampling container 11 has an inlet valve 13 at one end of a cylindrical container 12 made of metal, for example, stainless steel, and an outlet valve 14 at the other end. A sintered metal filter 15 is provided. The inlet valve 13 is a dual three-way valve in which the purge valve 13a and the introduction valve 13b are integrated so that the path to the inlet valve 13 can be purged more reliably.

  The sintered metal filter 15 is formed by baking fine metal powder at a temperature around the melting point to form micropores with a size of about several μm or less, as is well known. It is widely used as a filter for separating fine solids from various fluids. The low temperature liquefied gas is supplied from the upstream side of the sintered metal filter 15 at a temperature at which the liquid state can be maintained, that is, the temperature below the boiling point, and the temperature at which the low temperature liquefied gas cannot maintain the liquid state, that is, the temperature above the boiling point. By discharging into the cylindrical container 12, the low-temperature liquefied gas that has been subdivided into a size of several μm or less by passing through the fine holes of the sintered metal filter 15 is supplied to the cylindrical container 12. It is possible to quickly vaporize the gas and store the vaporized gas in the cylindrical container 12.

  Thereby, various impurity components contained in the low-temperature liquefied gas to be analyzed, particularly impurities such as sulfur components and moisture, can be reliably taken into the cylindrical container 12.

  The low temperature liquefied gas sampling device 20 using the gas sampling vessel 11 is for extracting a part of the low temperature liquefied gas stored in the cold evaporator 21 and storing the vaporized gas in the cylindrical vessel 12. It is equipped with various pipes for pre-cooling and purging, various valves and various devices.

  That is, the upstream piping between the inlet valve 13 of the gas sampling container 11 and the cold evaporator 21 is provided with a cold evaporator outlet valve 22, a discharge valve 23, and an inlet side shut-off valve 24 in order from the upstream side. A pressure gauge 25, a safety valve 26, an outlet side shut-off valve 27, and a flow meter 28 are provided in the downstream pipe downstream of the outlet valve 14 of the gas sampling container 11 in order from the upstream side.

  Hereinafter, a procedure for vaporizing the low-temperature liquefied gas in the cold evaporator 21 by the low-temperature liquefied gas sampling device 20 and storing it in the cylindrical container 12 of the gas sampling container 11 will be described.

  First, with all the valves closed, the upstream side pipe is connected to the inlet valve 13 and the downstream side pipe is connected to the outlet valve 14. Next, in order to release the gas remaining in the cylindrical container 12, the outlet valve 14 and the outlet side shut-off valve 27 are opened in this order, and the gas in the cylindrical container 12 is released to atmospheric pressure. When the inside of the cylindrical container 12 reaches atmospheric pressure, the outlet valve 14 and the outlet side shut-off valve 27 are closed in this order.

  Next, an impurity such as an air component is removed from the upstream side pipe, and a preliminary purge operation for cooling the upstream side pipe is performed. At this time, it is confirmed by an appropriate pressure gauge (not shown) that the outlet pressure of the cold evaporator 21 is 0.01 to 20 MPaG. If the outlet pressure exceeds 1 MPaG, an appropriate regulator (see FIG. (Not shown) to reduce the pressure to 1 MPaG or less.

  For purging in the pipe, the cold evaporator outlet valve 22, the discharge valve 23, the inlet side shut-off valve 24 and the purge valve 13a are opened, and the purge valve 13a and the inlet side shut-off valve 24 are closed after elapse of a predetermined time, for example, 1 minute. Until the piping is sufficiently cooled, the vaporized gas is released from the discharge valve 23, and the low-temperature liquefied gas is gradually released continuously.

  After completion of the preliminary purge operation, a purge operation for discharging impurities from the cylindrical container 12 is performed. First, a batch purge operation for repeating the pressure increase and the pressure decrease in the cylindrical container 12 is performed. In this batch purge operation, first, the inlet side shutoff valve 24, the introduction valve 13b, and the outlet valve 14 are opened in this order, and the discharge valve 23 is closed. Thereby, the gas which low temperature liquefied gas vaporized with the sintered metal filter 15 is introduce | transduced in the cylindrical container 12 through the upstream piping from the cold evaporator 21, and the pressure in the cylindrical container 12 rises gradually. When the indicated pressure of the pressure gauge 25 rises to a predetermined pressure, the inlet side shutoff valve 24 is closed and the outlet side shutoff valve 27 is opened, and the gas in the cylindrical container 12 is discharged from the downstream pipe. When the pressure in the cylindrical container 12 drops to a predetermined pressure, the outlet side shutoff valve 27 is closed and the inlet side shutoff valve 24 is opened.

  A flow purge operation in which gas is circulated in the cylindrical container 12 after a batch purge operation in which the inlet-side cutoff valve 24 and the outlet-side cutoff valve 27 are alternately opened to increase and decrease the pressure in the cylindrical container 12 is repeated a predetermined number of times. I do. In the flow purge operation, after confirming that the inlet side shutoff valve 24, the introduction valve 13b, and the outlet valve 14 are open, the outlet side shutoff valve 27 is opened. Thereby, the low-temperature liquefied gas from the cold evaporator 21 is vaporized by the sintered metal filter 15, and the vaporized gas passes through the cylindrical container 12 while being discharged from the downstream pipe. At this time, it adjusts suitably so that the gas flow rate measured with the flowmeter 28 may become a predetermined flow rate.

  When the total gas amount of the batch purge operation and the flow purge operation reaches a predetermined amount, for example, about 100 to 200 times the internal volume of the cylindrical container 12, the outlet side shut-off valve 27 is closed. Thus, a filling operation for filling the cylindrical container 12 with the gas vaporized from the low-temperature liquefied gas is performed. Then, if it is confirmed that the indicated pressure of the pressure gauge 25 is stable at a predetermined pressure, for example, 0.01 to 0.9 MPaG, and does not reach the ejection pressure of the safety valve 26, for example, 0.98 MPaG, The outlet valve 14 and the introduction valve 13b are closed in this order.

  As described above, the filling operation is performed after the preliminary purge operation, the batch purge operation, and the flow purge operation, so that the gas impurities staying in the upstream pipe and the cylindrical container 12 and the adhering impurities can be easily and reliably obtained. The low temperature liquefied gas stored in the cold evaporator 21 is extracted and only the gas vaporized by the sintered metal filter 15 is stored in the cylindrical container 12 of the gas sampling container 11. Can do. Then, the impurities in the low-temperature liquefied gas can be analyzed with high accuracy by transporting the gas sampling container 11 from which the upstream side pipe and the downstream side pipe have been removed to the analysis place and analyzing the impurities contained in the vaporized gas. it can.

  The sintered metal filter can be provided integrally with the inlet valve or can be provided at the gas inlet of the cylindrical container. Further, by providing a sintered metal filter in the inlet valve portion, a normal gas sampling container can be modified to a low-temperature liquefied gas sampling container.

DESCRIPTION OF SYMBOLS 11 ... Gas sampling container, 12 ... Cylindrical container, 13 ... Inlet valve, 13a ... Purge valve, 13b ... Inlet valve, 14 ... Outlet valve, 15 ... Sintered metal filter, 20 ... Low-temperature liquefied gas sampling device, 21 ... Cold Evaporator, 22 ... Cold evaporator outlet valve, 23 ... Release valve, 24 ... Inlet side shut-off valve, 25 ... Pressure gauge, 26 ... Safety valve, 27 ... Outlet side shut-off valve, 28 ... Flow meter

Claims (3)

  A gas sampling container having an inlet valve at one end of a cylindrical container and an outlet valve at the other end, wherein a sintered metal filter is provided downstream of the inlet valve.   The gas sampling container according to claim 1, wherein the inlet valve is a dual three-way valve in which a purge valve and an introduction valve are integrated.   The gas sampling container according to claim 1 or 2, wherein the sintered metal filter is provided integrally with the inlet valve.

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