JP2013029473A - Suction-type gas detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suction-type gas detector that hardly causes clogging of a filter member and is maintained easily.SOLUTION: A suction-type gas detector comprises: a gas introduction port 3 for introducing gas G; a gas discharge port for discharging the gas G; a gas passage P for communicating the gas introduction port 3 with the gas discharge port; gas suction means for sucking the gas into the gas passage P through the gas introduction port 3; a gas detection element for detecting the gas G sucked into the gas passage P; and a filter member 14 that is provided on an upper stream side of the gas passage than the gas suction means and the gas detection element. A trap member T for decreasing a flow rate of the gas G is provided in the gas passage P between the gas introduction port 3 and the filter member 14.

Description

  The present invention provides a gas introduction port for introducing gas, a gas discharge port for discharging gas, a gas flow path communicating the gas introduction port and the gas discharge port, and the gas flow through the gas introduction port. A gas suction means for sucking gas into the passage, a gas detection element for detecting the gas sucked into the gas flow path, and an upstream side of the gas flow path from the gas suction means and the gas detection element. The present invention relates to a suction type gas detector including a filter member.

  As a conventional suction type gas detector, for example, the one shown in Patent Document 1 is known. Here, a filter member is provided in the gas flow path between the gas introduction port and the gas detection element because water droplets, dust, or the like adheres to the gas detection element, which is likely to cause a failure or other malfunction. . While the filter member allows the gas to be detected to pass through, the filter member removes water droplets and dust contained in the introduced gas and prevents the gas from being attached to the gas detection element.

Japanese Patent Laid-Open No. 2002-52306 (FIG. 1)

  In the conventional suction type gas detector, if dust having a slightly larger particle size is present in the introduced gas, the filter member is likely to be clogged, resulting in poor gas flow and Sensitivity may decrease. In order to prevent this, the operator needs to clean and replace the filter member frequently to some extent, which sometimes complicates troublesome maintenance work.

  An object of the present invention is to provide a suction type gas detector that is less likely to clog a filter member and is easy to maintain.

  The first characteristic configuration relating to the suction type gas detector of the present invention includes a gas introduction port through which gas is introduced, a gas discharge port through which gas is discharged, and a gas that communicates the gas introduction port and the gas discharge port. A flow path, a gas suction means for sucking gas into the gas flow path via the gas inlet, a gas detection element for detecting the gas sucked into the gas flow path, the gas suction means and the gas detection A suction-type gas detector comprising a filter member provided upstream of the element on the upstream side of the gas flow path, wherein the gas flow rate is reduced in the gas flow path between the gas inlet and the filter member. The trap member to be used is provided.

[Action and effect]
According to this configuration, when the gas flow velocity is decelerated by the trap member, dust having a slightly larger particle size contained in the gas is easily captured by the trap member.
Therefore, clogging of the filter member is less likely to occur, and the frequency of cleaning and replacement work of the filter member is reduced, so that maintenance is facilitated.

  The second characteristic configuration is that the trap member includes a collision portion that causes a gas to collide, and a circulation hole through which the gas can flow around the collision portion.

[Action and effect]
According to this configuration, when the gas collides with the collision portion of the trap member, the flow velocity can be reliably reduced, and thereby the trapping effect of dust and the like by the trap member is enhanced.

  In the third characteristic configuration, the trap member includes a convex portion that rises toward the gas introduction port, and a concave portion that is formed between the convex portion and the inner peripheral surface of the gas flow path. The top plate constitutes the collision portion, and the flow hole is formed in the side wall of the convex portion.

[Action and effect]
According to this configuration, in addition to the gas flow colliding with the top plate of the convex portion of the trap member, the flow velocity is reliably reduced, and the decelerated dust and the like can be reliably captured by the concave portion of the trap member. .

It is the front view (a) and perspective view (b) of the suction type gas detector of the present invention. It is a longitudinal cross-sectional view in the arrow line II-II of FIG. It is a disassembled perspective view of a nozzle part. It is a perspective view of an attachment member of another form. FIG. 5 is a cross-sectional view taken along line VV in FIG. 2. It is a schematic block diagram of the suction type gas detector of this invention. It is the front view (a) and sectional drawing (b) of a gas exhaust port. It is the front view (a) and longitudinal cross-sectional view (b) of the gas discharge port after mounting | wearing a protrusion member. It is the front view (a) and longitudinal cross-sectional view (b) of the gas exhaust port after mounting | wearing with an adapter member.

  As an embodiment of the suction gas detector of the present invention, a portable suction gas detector will be described with reference to the drawings.

Embodiment
As shown in FIGS. 1A and 1B, the suction type gas detector according to the present embodiment includes a vertically long conical nozzle portion 1, a main body portion 20 including a gas detection element, a gas suction means, and the like. Is provided.

(Nozzle part)
As shown in FIGS. 2 and 3, the nozzle portion 1 includes an attachment member 2, a joint member 6, and a filter case 7.

  The attachment member 2 is made of a flexible material (rubber or the like), and includes an elongated cylindrical small-diameter portion 2a and a large-diameter portion 2b having an outer diameter larger than that of the small-diameter portion 2a. 2a and the large diameter part 2b are integrally molded. Moreover, the attachment member 2 has the through-hole P1 penetrated to a longitudinal direction over the small diameter part 2a and the large diameter part 2b.

  In the small-diameter portion 2a of the attachment member 2, an opening formed at the tip opposite to the large-diameter portion 2b is a gas introduction port 3 for introducing the gas G to be detected. In addition, a through portion 4 that communicates the through hole P1 of the small diameter portion 2a and the outside is provided on the side surface of the small diameter portion 2a of the attachment member 2 on the gas inlet 3 side.

  By providing this penetration part 4, even if an operator's hand accidentally touches and closes the gas introduction port 3, the external gas G is introduced into the gas flow path P through the penetration part 4. .

  In addition to the configuration of the penetrating portion 4 described above, a notched portion 5 that is notched from the gas inlet 3 to the side surface of the attachment member 2 may be provided as shown in FIG. Even with this configuration, even if the operator's hand or the like accidentally touches the gas inlet 3 to block it, the external gas G is introduced into the gas flow path P through the notch 5.

  As shown in FIGS. 2 and 3, the attachment member 2 is prevented from coming off by the nipple portion 6 a of the joint member 6, but can be removed by pulling with some force. Therefore, it can be appropriately replaced with an attachment member having a shape more suitable for the situation, for example, an attachment member having a longer shape, if necessary.

  The joint member 6 includes a nipple portion 6a having a tapered surface continuous in the longitudinal direction on the outer peripheral surface, and a large diameter portion 6b having an outer diameter larger than that of the nipple portion 6a. The nipple portion 6a and the large diameter portion 6b include It is molded integrally. The joint member 6 has a through hole P2 that penetrates in the longitudinal direction across the nipple portion 6a and the large diameter portion 6b.

  The filter case 7 includes an upper portion 8 of a hollow cylindrical member, a lower portion 9 of the same hollow cylindrical member, and a disk-shaped filter member 14 for removing water droplets and dust contained in the gas G. With.

  The upper part 8 and the lower part 9 of the filter case 7 are configured so as to be fitted and connected to each other. When the filter member 14 and the O-ring R1 are arranged in the lower portion 9 and one end of the upper portion 8 is fitted into the lower portion 9, the upper portion 8 An accommodation space 15 in which the filter member 14 can be accommodated is formed between the lower portion 9 and the filter member 14 is accommodated in the accommodation space 15.

  A trap member T that reduces the flow rate of the gas G is provided at an intermediate position inside the upper portion 8 of the filter case 7.

  As shown in FIGS. 2 and 5, the trap member T includes a convex portion 10 that rises toward the gas inlet 3, and a concave portion 11 that is formed between the convex portion 10 and the inner peripheral surface of the upper portion 8. Prepare. In this embodiment, the concave portion 11 extends from the inner peripheral surface of the upper portion 8 to the lower portion 9 side and is connected to an end portion different from the top plate 13 side of the convex portion 10, so that the cross-sectional shape is V-shaped. It has become a shape.

  A plurality of flow holes 12 through which the gas G can flow are formed in a portion extending from the top plate 13 to the side wall of the convex portion 10. The top plate 13 (collision part) of the convex part 10 is arranged on the axis of the through hole P3 of the upper part 8.

  As shown in FIG. 3, after the nozzle portion 1 externally fits the large-diameter portion 6b of the joint member 6 to the upper portion 8 of the filter case 7 via the O-ring R2, the nipple portion 6a of the joint member 6 is fitted. The attachment member 2 can be assembled by being pushed into the opening of the large diameter portion 2b. At this time, the shaft center of the through hole P1 of the attachment member 2, the shaft center of the through hole P2 of the joint member 6, and the shaft center of the through hole P3 of the upper portion 8 and the through hole P4 of the lower portion 9 of the filter case 7 are Each is configured to match.

  As shown in FIGS. 1A, 1 </ b> B, and 2, the nozzle portion 1 has a main body portion on the opposite side of the lower portion 9 of the filter case 7 from the side on which the upper portion 8 is fitted. The main body portion 20 is mounted by being externally fitted to a mounting portion (not shown) protruding from the upper surface of the main body 20.

[Main body]
As shown in FIG. 6, the main body 20 includes a cylindrical housing 21 that forms part of the gas flow path P, a gas detection element 22 that detects a gas to be detected, and a diaphragm pump 23 (gas) that sucks the gas. Suction means), gas discharge port 24 through which gas is discharged, flow sensor 25 (blockage detection means) for detecting the flow rate of gas G flowing through the gas flow path P, and diaphragm pump 23 when the flow sensor 25 detects a blockage state. A control unit 26 that stops the suction operation and a release switch 27 (return unit) that restarts the diaphragm pump 23 stopped by the control unit 26 are configured.

  Examples of the gas G that can be detected by the suction gas detector of the present invention include flammable gases such as methane, toxic gases such as carbon monoxide and hydrogen sulfide, and odors.

  Moreover, as the gas detection element 22 applicable to the suction type gas detector of the present invention, it can be appropriately selected according to the type of the gas G to be detected, but for example, on the surface of a metal oxide semiconductor Measures the electrical conductivity change due to gas adsorption as a change in resistance value seen from both ends of the platinum wire coil, and detects the gas by detecting the gas. A constant potential electrolytic detection element for detecting gas, a gas thermal conductivity detection element for detecting gas by measuring a temperature change of a heating element (platinum wire coil) due to a difference in thermal conductivity of the gas, and a catalyst surface And a catalytic combustion type detecting element for detecting a gas by measuring a temperature rise of a platinum wire coil due to gas catalytic combustion.

  One end of the housing 21 is connected to a mounting portion (not shown) of the main body 20, and the other end is connected to the gas discharge port 24. Thereby, the gas introduction port 3 of the nozzle part 1 and the gas discharge port 24 of the main-body part 20 are connected, and the gas flow path P through which the gas G flows is formed. That is, the gas flow path P is formed from the upstream side of the through hole P1 (see FIG. 2) of the attachment member 2 of the nozzle portion 1, the through hole P2 of the joint member 6 (see FIG. 2), and the upper portion 8 of the filter case 7. The through hole P3 (see FIG. 2), the through hole P4 (see FIG. 2) of the lower portion 9, and the housing 21 of the main body 20 are formed to communicate with each other.

  In the housing 21, a gas detection element 22, a flow sensor 25, and a diaphragm pump 23 are arranged in this order from the upstream side of the gas flow path P.

  As shown in FIGS. 1 (a) and 1 (b), the gas discharge port 24 opens on the lateral side surface of the main body 20. As shown in FIGS. 7A and 7B, a circular wall portion 28 is erected on the lateral side surface of the main body portion 20 so as to surround the gas discharge port 24. The wall portion 28 is provided with a communication portion 29 that allows the gas discharge port 24 to communicate with the outside.

  Also, as shown in FIGS. 8A and 8B, a projecting member 30 having a cross-shaped cross section is provided detachably with respect to the gas discharge port 24. As shown in FIG. 8A, the gas discharge port 24 is divided into four by the protruding member 30, and gas is discharged from these four gaps. Further, as shown in FIG. 8B, the protruding member 30 is fitted into the gas discharge port 24 while being locked to the periphery of the gas discharge port 24 in a state of protruding outward from the gas discharge port 24. .

  9A and 9B, an adapter member 31 that is a hollow cylindrical member can be attached to the gas discharge port 24 instead of the protruding member 30. The adapter member 31 is formed by adhering a rubber member that is in close contact with the inner peripheral surface of the gas discharge port 24 and a polycarbonate member that protrudes from the gas discharge port 24. The adapter member 31 is attached to the adapter member 31. Further, by connecting a hose or the like, the exhausted gas G can be guided to another measuring device and further analysis can be performed.

[Description of operation]
As shown in FIG. 2, the gas G sucked from the gas inlet 3 of the nozzle portion 1 by driving the diaphragm pump 23 passes through the through hole P1 of the attachment member 2 and the through hole P2 of the joint member 6, and then passes through the filter. Colliding with the top plate 13 of the convex portion 10 of the trap member T of the case 7, the flow velocity is once decelerated. Thereby, the gas G passes through the flow hole 12 of the convex portion 10 while the dust having a slightly larger particle size contained in the gas G is captured in the concave portion 11 of the trap member T.

  Next, the gas G reaches the filter member 14, and water droplets and fine dust contained in the gas G are removed.

  The gas G that has passed through the filter member 14 passes through the through hole P4 in the lower portion 9 of the filter case 7 and is introduced into the housing 21 of the main body 20.

  As shown in FIG. 6, the gas G introduced into the housing 21 is detected by the gas detection element 22, and the detection result is sent to the control unit 26 via the gas detection element drive circuit 32 connected to the gas detection element 22. Is output.

  The flow sensor 25 detects the closed state of the gas flow path P by detecting the flow rate of the gas G flowing through the gas flow path P. The flow rate detected by the flow sensor 25 is output as a signal to the control unit 26 via the flow sensor drive circuit 33 connected to the flow sensor 25.

  The gas G that has passed through the gas detection element 22 and the flow sensor 25 passes through the diaphragm pump 23 and is discharged from the gas discharge port 24.

  When the gas G is being sucked, for example, when water or the like enters the gas flow path P of the nozzle unit 1 to prevent the gas G from being sucked, the flow sensor 25 causes the gas G flowing through the gas flow path P to flow. It is detected that the flow rate is less than the predetermined gas flow rate, and is output to the control unit 26 via the flow sensor drive circuit 33.

  The control unit 26 to which this signal is input immediately stops the suction operation by the diaphragm pump 23 to prevent water or the like from entering the housing 21 of the main body unit 20.

  Next, the diaphragm pump 23 stopped by the control unit 26 is restarted by turning on the release switch 27 provided in the main body unit 20 with the obstruction such as water removed from the gas flow path P. Can be made.

  The suction type gas detector according to the present invention can be used to detect various gases such as flammable gas, toxic gas, and odor.

DESCRIPTION OF SYMBOLS 1 Nozzle part 2 Attachment member 2a Small diameter part 2b Large diameter part 3 Gas inlet 4 Penetration part 5 Notch part 6 Joint member 6a Nipple part 6b Large diameter part 7 Filter case 8 Upper part 9 Lower part 10 Convex part 11 Concave part 12 Flow hole 13 Top plate (collision part)
14 Filter member 15 Accommodating space 20 Main body 21 Housing 22 Gas detection element 23 Diaphragm pump (gas suction means)
24 Gas outlet 25 Flow sensor (blockage detection means)
26 Control Unit 27 Release Switch (Return Unit)
28 Wall part 29 Communication part 30 Projection member 31 Adapter member 32 Gas detection element drive circuit 33 Flow sensor drive circuit P Gas flow path P1-P4 Through-hole R1, R2 O-ring T Trap member

Claims (3)

A gas inlet through which gas is introduced; a gas outlet through which gas is discharged; a gas flow path communicating with the gas inlet and the gas outlet; and the gas flow path through the gas inlet. Gas suction means for sucking gas, gas detection element for detecting gas sucked into the gas flow path, and a filter member provided on the upstream side of the gas flow path with respect to the gas suction means and the gas detection element A suction gas detector comprising:
The suction type gas detector which provided the trap member which decelerates the flow velocity of gas in the gas flow path between the said gas inlet and the said filter member.   The suction-type gas detector according to claim 1, wherein the trap member includes a collision portion that causes a gas to collide, and a flow hole through which the gas can flow around the collision portion.   The trap member includes a convex portion that rises toward the gas inlet, and a concave portion that is formed between the convex portion and the inner peripheral surface of the gas flow path, and the top plate of the convex portion collides with the collision portion. The suction type gas detector according to claim 2, wherein the flow hole is formed in a side wall of the convex portion.

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