CN213408029U - Filter and gas sensor - Google Patents

Abstract

The present application relates to a filter for providing filtered gas to the gas sensor, wherein the filter is configured for being detachably mounted at the air sensor and for passing gas through the filter to a sensing portion of the gas sensor, wherein the filter comprises: an inlet portion that prevents impurities from entering the gas sensor when gas enters; a filter part including a filter material configured to filter impurity gas from the gas entering from the inlet part; and an outlet part configured to block the filter material and allow the gas to flow out of the filter part, wherein the inlet part and the outlet part are located at both ends of the filter part, respectively.

Description

Filter and gas sensor

Technical Field

The present application relates to a filter for filtered gas provided to a gas sensor. The application also relates to a gas sensor having such a filter.

Background

In many fields, it is necessary to monitor the concentration of a certain gas with a gas sensor for a long time. To improve the monitoring accuracy, a filter is usually disposed in the gas sensor to filter out impurities and other interfering gases, which are then supplied to the sensing component of the gas sensor.

Many gas sensors with filters are disclosed in the prior art, for example in the documents US5560810, US2017/0276634a 1. However, the prior art filters are often disposed within the gas sensor, which results in the need to replace the entire gas sensor after the filter fails (even if the sensing components of the gas sensor are still functioning properly). Furthermore, the reference document US2018/0085696a1 discloses a filter-replaceable gas sensor, wherein a filter element is mounted to the gas sensor through a filter housing.

SUMMERY OF THE UTILITY MODEL

Based on the above prior art, the present application aims to solve or at least alleviate the problems in the prior art, namely: so that the filter of the gas sensor can be replaced at a lower cost and more conveniently.

According to the present application, a filter for providing filtered gas to a gas sensor is proposed, wherein the filter is configured for being detachably mounted at the gas sensor and for passing gas through the filter to a sensing portion of the gas sensor, wherein the filter comprises:

an inlet portion that prevents impurities from entering the gas sensor when gas enters;

a filter part including a filter material configured to filter impurity gas from the gas entering from the inlet part; and

an outlet portion configured to obstruct the filter material and to allow the gas to flow out of the filter portion, wherein,

the inlet portion and the outlet portion are respectively located at both ends of the filter portion.

According to some embodiments of the present application, the filter portion has a housing.

According to some embodiments of the present application, wherein the filter portion is connected at both ends thereof to the inlet portion and the outlet portion, respectively.

According to some embodiments of the application, wherein at least one end of the filter house is configured with a broadside protruding laterally with respect to the body of the filter house.

According to some embodiments of the application, wherein a broad side of the filter house facing the inlet portion projects laterally outwards with respect to a main body of the filter house.

According to some embodiments of the application, wherein in the inlet portion, an adhesive is provided around a region where the inlet portion is connected with the broad side of the filter portion, and the inlet portion is adhered to the gas sensor housing with the adhesive when the filter is mounted at the gas sensor.

According to some embodiments of the present application, wherein the inlet portion and/or the outlet portion are configured membranally.

According to some embodiments of the present application, wherein the inlet portion and the outlet portion are made of a gas permeable material.

According to some embodiments of the application, wherein the inlet portion is comprised of a hydrophobic material for keeping the filter material dry.

The application also relates to a gas sensor comprising a sensing portion, wherein a filter according to any of the embodiments of the application is further comprised.

According to some embodiments of the application, wherein the filter is provided at a top of the gas sensor and/or a recess is provided at the gas sensor for receiving the filter in a form-fitting manner.

According to the filter disclosed herein, it is detachably mounted at the gas sensor and filters gas entering the sensing portion of the gas sensor. When the filter fails, the filter can be conveniently detached from the gas sensor without replacing the whole gas sensor. This saves the cost of replacing the filter of the gas sensor.

Drawings

The disclosure of the present application will become more readily understood with reference to the drawings. As is readily understood by those skilled in the art: these drawings are for illustrative purposes only and are not intended to constitute a limitation on the scope of the present application. Moreover, in the drawings, like numerals are used to indicate like parts, and in which:

FIG. 1 schematically illustrates components of a filter at an inverted filter angle;

FIG. 2 schematically illustrates the components of the filter at a normal resting angle; and

fig. 3 illustrates exemplary placement of a filter into a gas sensor.

Detailed Description

It is to be noted herein that the drawings and embodiments disclosed herein are exemplary and should not be construed as limiting the present application. The scope of the present application also includes other filter or sensor components that implement the same principles as the present application.

As can be seen with reference to fig. 1 or 2, the filter 1 disclosed herein can be detachably mounted at the gas sensor 2 in a situation of use. Here, the filter includes an inlet portion 10, a filter portion 20, and an outlet portion 30. The filter 1 is in normal use placed with the inlet portion 10 facing the outside environment, in which case the inlet portion 10 is able to prevent the ingress of impurities, such as dust, water, etc., when gas enters the filter or gas sensor. A filter portion 20 containing a filter material 21 therein is provided after the inlet portion 10 along the direction of the gas flow, wherein the filter material 21 in the filter portion 20 can filter out foreign gas that may interfere with the detection of the target gas by using a physical adsorption principle or by using other applicable filtering principles such as a chemical reaction. Next, an outlet portion 30 is provided at the outlet end of the filter portion 20, which faces the gas sensor when the filter is in normal use. The outlet section 30 here, on the one hand, blocks the filter material 21 from entering the gas sensor and, on the other hand, also allows the target gas to enter the gas sensor smoothly. In the context of the present application, the inlet portion 10 and the outlet portion 30 are respectively provided at both ends of the filter portion 20, for example by means of gluing. Of course, other ways of connecting the inlet section and/or the outlet section to the filter section are also conceivable here.

The filter part 20 can be configured, for example, as a shell or comprise a housing in which a filter material 21 is accommodated. In this case, a broadside protruding transversely to the housing may be provided at least one end of the housing for connection with the inlet 10 and/or outlet 30. Such a broadside can facilitate a sealed connection of the inlet portion 10 and/or the outlet portion 30 to the filter portion 20. That is, the inlet 10 and/or the outlet 30 are fixed to the filter part 20 by being connected to a wide side having a larger area than that of the end of the original housing.

In some embodiments of the present application, referring to fig. 1, of the two wide sides of the filter house 20, the wide side connected to the inlet part 10 or facing the inlet part 10 is protruded laterally outward with respect to the housing of the filter house 20. This laterally outwardly projecting broadside arrangement can prevent gas from passing through the gap between the filter and the gas sensor when the filter is mounted on the gas sensor, but only through the filter to the gas sensor.

Here, in the case where the inlet portion 10 is bonded to the filter portion 20 of the filter, an adhesive 11 is provided at the inlet portion 10 around a region thereof bonded to the filter portion 20, so that the inlet portion 10 can be bonded to the gas sensor by the adhesive when the filter is mounted thereto. This mounting can improve the sealing of the gas sensor to some extent. When the filter is removed, the inlet portion 10 is simply torn off from the gas sensor and the filter is then removed.

In some embodiments of the present application, the inlet 10 and/or the outlet 30 may be provided as an inlet membrane and/or an outlet membrane, which are applied to both ends of the housing-like filter part 20 to achieve the effect of gas circulation. It is contemplated that the inlet portion 10 is provided as a Polytetrafluoroethylene (PTFE) membrane. Of course other membrane materials having similar functions are also contemplated. The housing material of the filter house 20 can be selected from plastics, such as ABS, PP or PE plastics. And the filter material 21 in the filter part 20 can be selected from activated carbon or potassium permanganate. Of course, other types of materials may be selected depending on the environment of use and the requirements. In contrast, the outlet portion 30 of the filter should be made of a material that is easy to allow gas to flow smoothly, i.e., has low gas resistance, so that it is easier for gas to enter the sensing portion of the gas sensor through the outlet portion 30. On the other hand, the outlet portion 30 also prevents the filter material 21 in the filter portion 20 from entering the gas sensor. In this regard, it is contemplated herein to use a gas permeable material to form the outlet section 30, such as a porous material having a pore size of 5 microns. Furthermore, the material of the outlet portion 30 is hydrophobic to avoid moisture exposure of the gas sensor.

Furthermore, the present application relates to a gas sensor comprising a sensing portion and a filter as disclosed in any of the embodiments of the present application. In this case, it can be provided that the filter is arranged on top of the gas sensor during use. Furthermore, a recess can be provided in the gas sensor for the filter to be received in a form-fitting manner in the gas sensor.

Claims (10)

1. A filter for providing filtered gas to a gas sensor, the filter configured for being removably mounted at the gas sensor and for allowing gas to pass through the filter to a sensing portion of the gas sensor, wherein the filter comprises:

an inlet portion that prevents impurities from entering the gas sensor when gas enters;

a filter part including a filter material configured to filter impurity gas from the gas entering from the inlet part; and

an outlet portion configured to obstruct the filter material and to allow the gas to flow out of the filter portion, wherein,

the inlet portion and the outlet portion are respectively located at both ends of the filter portion.

2. The filter of claim 1, wherein the filter portion has a housing.

3. A filter as set forth in claim 2 wherein said filter portion is connected at both ends to said inlet portion and said outlet portion, respectively.

4. A filter as set forth in claim 3, characterized in that at least one end of the filter house is configured with a broadside projecting transversely with respect to the body of the filter house.

5. A filter as set forth in claim 3 wherein a broad side of said filter portion facing said inlet portion projects laterally outwardly relative to a main body of said filter portion.

6. A filter as set forth in claim 5 wherein an adhesive is provided in said inlet portion around the area where said inlet portion joins the broad side of said filter portion, said inlet portion being adhered to said gas sensor housing with the adhesive when said filter is mounted to said gas sensor.

7. A filter according to claim 1, wherein the inlet portion and/or the outlet portion is provided as an inlet membrane and/or an outlet membrane.

8. The filter of claim 1, wherein the inlet portion and the outlet portion are made of a gas permeable material.

9. A filter as set forth in claim 1 wherein said inlet portion is constructed of a hydrophobic material for keeping said filter material dry.

10. A gas sensor comprising a sensing portion, characterized by further comprising a filter according to any one of claims 1 to 9.

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