JPH0341773Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a filter element used for removing dust and mist from sample gas in automobile exhaust gas measuring devices and the like.

[Conventional technology]

As a filter for removing dust and mist from a sample gas in an automobile exhaust gas measuring device, for example, a filter in which a primary filter 11 and a secondary filter 12 shown in FIG. 3 are provided independently of each other is known.

The filter element 13 used in the primary filter 11 is, as shown in FIG. 4A,
A pipe-shaped element 14 made of fibers made of a material such as ceramic and having an appropriate thickness is sandwiched between an inner wire mesh 15 and an outer wire mesh 16 from the inside and outside, and a plurality of elements are sandwiched between the inner wire mesh 15 and the outer wire mesh 16. The folds 17 are formed so that the inner and outer surface areas of the element 14 are increased. And inner wire mesh 15
The positions of the folds 17 of the outer wire mesh 16 are made to substantially coincide with each other, so that the thickness of the element 14 is substantially the same throughout. A ring-shaped cap 18 is attached to the end of the element 14 and is made of metal such as stainless steel. The caps 18 are attached to both ends of the element 14, although one of them is not shown.

As shown in FIG. 4B, the element 19 used in the secondary filter 12 is configured in the shape of a bottomed pipe made of glass fiber or filter paper, and the element 19 has a higher density than the element 14. be.

In the above configuration, the sample gas first passes through the filter element 13 of the primary filter 11;
Next, it passes through element 19 of secondary filter 12.

[Problem that the invention attempts to solve]

Since it is necessary to use two conventional elements with different densities as described above, a large amount of gas accumulates in the filters 11 and 12, and when used in a measuring device, the response speed becomes slow. There's a problem. When replacing the elements, it is necessary to replace the two elements 14 and 19 separately, which increases the effort and effort.
There are also problems with poor maintainability. Further, the filter element 13 used in the primary filter 11 is entirely covered with wire meshes 15 and 16 from the inner and outer peripheral surfaces.
Because they are pressurized to almost the same state, their density increases, and the filtration action is performed only on the surface, which tends to clog and reduces the efficiency of removing dust etc., resulting in a shortened usable period. There is.

This invention solves the above-mentioned problems, and when used in a gas measuring device, it has a fast response speed, reduces the effort required for replacement, improves maintainability, and eliminates dust, etc. The purpose of the present invention is to obtain a gas filter element with high removal efficiency.

[Means for solving problems]

The filter element of the present invention has an inner element made of glass fiber or filter paper formed into a pipe shape with a circular cross section, and an outer element made of ceramic fiber arranged around the entire outer periphery of the inner element. The external element is covered with a net provided with a net, and the thickness of the external element is thicker at the peaks of the net and thinner at the valleys.

[Effect]

The filter element of the present invention allows a sample gas to pass from the outer element side to the inner element side, and removes dust, mist, etc. from the sample gas with the inner and outer elements.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings.

In FIGS. 1 and 2, reference numeral 1 denotes a pipe-shaped internal element with one end closed, and is made of a dense material such as glass fiber or filter paper. Reference numeral 2 denotes an external element that covers the entire outer circumference of the internal element 1, and is made of ceramic fiber made into a cotton-like structure, and has a higher density than the internal element 1. A pipe-shaped net 3 covers the entire outer periphery of the external element 2, and is made of metal or synthetic resin such as fluorine resin, and is bent inward and outward in the circumferential direction to form a plurality of pleats 4. Therefore, the outer element 2 has a larger surface area and also has a different thickness such that it is thicker at the peaks of the net 3 and thinner at the valleys. Here, the thickness at the peaks and valleys of the external element 2 refers to the thickness of the internal element 1 in FIG. The points that intersect with the outer circumference are A′,
B′, the length of line AA′ is the external element 2
The length of line BB' is the thickness of the outer element 2 at the troughs.

The ends of the outer element 2 and the net 3 are then bonded with adhesive 5 on the closed side of the inner element 1.
is closed.

In the above configuration, the sample gas and the like are passed from the outer element 2 side to the inner element 1 side, and the outer element 2 and the inner element 1 remove dust and mist contained in the sample gas and the like.

[Effect of idea]

The present invention is constructed as described above, and the filter element of the present invention has an external element overlaid on the internal element, making it possible to complete gas filtration with only this element, reducing the amount of gas accumulation by half. However, if used in a measuring device, its response speed can be increased. Moreover, since only one element needs to be replaced, the maintainability can be improved. The inner element has a circular cross-section, and the outer element is covered with a net with multiple pleats, making the thickness of the outer element different. Therefore, gas can easily pass through the outer element. Dust and other substances become clogged from the thinner parts to the thicker parts, and the thicker parts of the external element are less compressed by the net, and the dust and mist are captured both on the surface and inside, so the dust and mist caused by the external element is reduced. Improved mist removal effect,
Moreover, the usable period can be extended.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention,
FIG. 1 is a perspective view, and FIG. 2 is a sectional view. FIG. 3 is a configuration diagram of a conventional example, and FIGS. 4A and 4B are perspective views of the conventional example. 1...Internal element, 2...External element, 3...Net, 4...Fold.

Claims (1)

[Scope of utility model registration request] An outer element made of ceramic fiber is arranged around the entire outer periphery of an inner element made of glass fiber or filter paper and formed into a pipe shape with a circular cross section, and the outer surface of this outer element is covered with a net having a plurality of pleats. , a gas filter element characterized in that the thickness of the external element is thicker at the peaks of the net and thinner at the valleys.