JP2015102473A - Hydrogen sulfide removal filter for gas analysis - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrogen sulfide removal filter for gas analysis capable of determining a lifetime surely even when a shading container is used.SOLUTION: A hydrogen sulfide removal filter for gas analysis is constituted as follows. A granular material 7 containing a silver salt is stored in a cylindrical container 1 in which at least a shell part 2 has shading property, and a gas inflow port 3 is formed on one end and a gas outflow port 4 is formed on the other end, and an agent discoloring by being reacted with hydrogen sulfide is impregnated into a particle push plate 6 arranged at least on the gas outflow port 4.

Description

  The present invention relates to a filter for removing hydrogen sulfide from a test gas flowing into a gas detector.

For example, in the field of petrochemistry and oil drilling, dangerous gases such as hydrogen sulfide (H2S), sulfur dioxide (SO2), acetylene (CH4), carbon monoxide (CO) are present in high concentrations. It is necessary to constantly monitor the concentration of.
Among these gases, when measuring sulfur dioxide and carbon monoxide, a constant potential is usually applied between the working electrode that forms the interface with the electrolyte and the counter electrode immersed in the electrolyte, A constant potential electrolysis type electrochemical sensor using the fact that the electrolysis current varies depending on the gas concentration is used.

When a constant potential electrolysis type electrochemical sensor is used in such a situation where hydrogen sulfide is present at a high concentration, the influence of interference due to hydrogen sulfide is large and the target gas cannot be measured accurately.

For this reason, as seen in Patent Document 1, a filter is used in which a granular material in which a silver salt such as silver sulfate is supported on a granular carrier such as alumina is housed in a container whose inside is visible.
According to this, hydrogen sulfide contained in the test gas reacts and is captured sequentially from the silver sulfate particles on the inlet side, and the measurement target gas passes through the silver sulfate particles and flows into the detector from the gas outlet port. To do.
In this way, when hydrogen sulfide is reacted and absorbed up to the silver sulfate particles near the gas outlet, the lifetime of the filter is exhausted.

  Since the silver sulfate particles are blackened when hydrogen sulfide is reacted and absorbed, the size (length) of the blackened region is seen from the outside of the container to determine the filter replacement time. However, since silver salts are blackened by external light, there is a problem that an error occurs in determining the life. In order to avoid this, if it is housed in a light-shielding container, a new problem arises that the blackened area cannot be seen.

JP 2003-232770 A

  The present invention has been made in view of such problems, and an object thereof is to provide a hydrogen sulfide removal filter for gas analysis that can accurately determine the life even when a light-shielding container is used. That is.

  In order to achieve such a problem, the present invention provides a granular container containing silver salt in a cylindrical container in which at least a body portion has a light shielding property, a gas inlet is formed at one end, and a gas outlet is formed at the other end. In addition to containing the body, at least a gas-permeable particle pushing plate disposed at the gas outlet is impregnated with an agent that changes color by reacting with hydrogen sulfide.

  The lifetime can be reliably determined by observing the color of the particle push plate on the outlet side.

It is sectional drawing which shows one Example of this invention.

  The cylindrical container 1 has at least a body portion 2 having a light shielding property, a gas inlet 3 formed at one end, and a gas outlet 4 formed at the other end. It is configured as a filter by containing particles 7 made of silver salt, for example, silver sulfate (Ag 2 SO 4), or particles 7 made of silver salt itself by arranging particle stop plates 5 and 6 having air permeability.

  At least the particle stop plate 6 disposed on the gas outlet side is impregnated with an agent that reacts with hydrogen sulfide and changes color, for example, silver salt. That is, the air-permeable plate-like body composed of a water-absorbing material, such as cellulose, is loaded with an agent by a method of absorbing and drying a material that changes color by reacting with hydrogen sulfide, such as an aqueous silver salt solution. .

  In this embodiment, when the gas inlet 3 and the gas outlet 4 of the filter are connected to the sampling flow path and the gas to be measured is sent to the sensor, the hydrogen sulfide contained in the gas is the silver sulfate of the grains 7 on the inlet side. The gas to be measured passes through the particles 7 and flows into the sensor from the gas outlet 4.

  Even when external light is irradiated in the process of using the filter, silver sulfate is not blackened by the photoreaction because the container constituting the filter has a light shielding property.

  When hydrogen sulfide is absorbed to the particles near the gas outlet 4 in this way, the hydrogen sulfide finally comes into contact with the particle stop plate 6 on the outlet side. As a result, the particle stop plate 6 on the outlet side is blackened, so that it can be determined that the filter has reached the end of its life by viewing from the outlet side.

In the above-described embodiment, silver salt is supported only on the particle stop plate 6 on the gas outlet side. However, silver salt is supported not only on the gas outlet side but also on the particle stop plate 5 on the gas inlet side. In this case, the gas outlet and the gas inlet can be connected to the flow path without the need to strictly distinguish them.
Further, in the above-described embodiments, the barrel portion is provided with a light shielding property to substantially prevent blackening of the silver salt due to light. However, even if the whole cylindrical container is provided with the light shielding property, the gas inlet port 3. The color of the particle stop plate can be determined by visual observation from the through hole of the gas outlet 4.

DESCRIPTION OF SYMBOLS 1 Cylindrical container 2 Trunk part 3 Gas inflow port 4 Gas outflow port 5, 6 Grain stop plate 7 Granule which carries silver sulfate

Claims (1)

At least the barrel portion has a light shielding property, and a granular container containing silver salt is contained in a cylindrical container having a gas inlet at one end and a gas outlet at the other end, and at least at the gas outlet. A hydrogen sulfide removal filter for gas analysis, in which a particle pusher plate is impregnated with an agent that changes color by reacting with hydrogen sulfide.

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