GB2148736A

GB2148736A - Activated-carbon fluid filter

Info

Publication number: GB2148736A
Application number: GB08327596A
Authority: GB
Inventors: Dennis Albert George Marshall
Original assignee: Marshall D A G
Current assignee: Marshall D A G
Priority date: 1983-10-14
Filing date: 1983-10-14
Publication date: 1985-06-05
Also published as: GB2148736B; GB8327596D0

Abstract

The filter comprises an outer casing (10) and an inner casing (12) which has a body portion (18) joined to a neck portion (20) by a frusto-conical shoulder portion (22). Within the body portion (18) of the inner casing are a number of adjacent layers (24) of cellular material with activated-carbon particles in their cells. These layers of cellular material extend across the entire cross-section of the said body portion (18) of the inner casing (12) so that no fluid is able to pass upwards through the inner casing without being scrubbed by the activated-carbon particles in the cellular layers (24). The outer casing (10) co-operates with the neck portion (20) of the inner casing (12) to support further layers (28) of cellular material which likewise have activated- carbon particles in their cells. <IMAGE>

Description

SPECIFICATION Activated-carbon fluid filter This invention relates to activated-carbon fluid filters.

According to the invention, an activated-carbon fluid filter comprises spaced-apart inner and outer casings each having a through-passage for the flow of fluid (usually air) through the filter in separate streams, in which the inner casing has a body portion and a neck portion, which body portion supports within itself and over its entire crosssection a number of adjacent layers of cellular material with activated-carbon particles in their cells for the removal of noxious substances from fluid passing through the inner casing, while the outer casing co-operates with the neck portion of the inner casing to support other layers of cellular material likewise having activated-carbon particles in their cells, the said layers being arranged to bridge entirely the gap between the outer casing and the neck portion of the inner casing for the removal of noxious substances from fluid passing through the outer casing.

Preferably, the axes of the cells in adjacent layers of cellular material extend at different angles to the vertical and also in different directions when the layers are viewed from above or below. The effect of this is that the filter can be used in any desired orientation, as the activated-carbon particles in the cells will thus be able to prevent any fluid from passing through the filter without being subjected to the scrubbing action of the said particles.

Two examples of fluid filters in accordance with the invention are shown in the accompanying drawings, in which: Figure 1 is a vertical section through one of the filters; Figure 2 is a half-section through the other filter; and Figure 3 is an enlarged view of part of Figures 1 and 2.

The activated-carbon fluid filters shown in the drawings are designed to filter air or other gaseous fluid so as to remove noxious substances therefrom.

The filters can be used in a wide variety of applications and, in particular, are adapted to be positioned in a duct or container.

As will be seen from Figures 1 and 2, each filter comprises an outer casing 10 which, in this particular instance, is of circular cross-section. It is, however, to be understood that the outer casing could be of some other cross-section-for example, oval or even rectangular.

Within the outer casing 10 there is an inner casing 12 which is spaced away from the outer casing so that the outer casing has a through-passage 14 for the flow of fluid through the filter. The inner casing 12 likewise has a through-passage 16 for the flow of a separate stream of fluid through the filter. In other words, fluid passes.through the filter in two separate streams.

The inner casing 12 has a body portion 18 which is joined to a neck portion 20 by a frusto-conical shoulder portion 22. Within the body portion 18 of the inner casing there are a number of adjacent layers 24 of cellular material with activated-carbon particles in their cells for the removal of noxious substances from fluid passing through the inner casing. As will be seen, these layers of cellular material extend across the entire cross-section of the said body portion 18 of the inner casing 12 so that no fluid is able to pass upwards through the inner casing without being scrubbed by the activated-carbon particles in the cellular layers 24.

The ends of the cells in the cellular layers 24 are closed by appropriate screens which are bonded to the layers of cellular material by means of metal mesh supports having a coating of thermo-plastics material. A lower coarse screen 26 is also provided at the lowermost part of the inner casing 12.

The outer casing 10 co-operates with the neck portion 20 of the inner casing 12 to support further layers 28 of cellular material which likewise have activated-carbon particles in their cells, the layers 28 being arranged to bridge entirely the gap between the outer casing 10 and the neck portion 20 of the inner casing 12 for the removal of noxious substances from fluid passing upwards through the passage 14 of the outer casing. This arrangement ensures that no fluid can pass upwards through the passage 14 of the outer casing 10 without being scrubbed by the activated-carbon particles in the cellular layers 28. As with the cellular layers 24, the ends of the cells in the cellular layers 28 are closed by screens which are bonded to the cellular layers by thermo-plastics coatings on metal mesh supports.There is also a coarse screen 30 arranged immediately below the lowermost cellular layer 28.

In the case of the filter shown in Figure 1, the upper and lower ends of the outer casing 10 have synthetic plastics end rings or caps 32 and 34 provided with flexible leaf seals 36. This allows the casing 10 to be inserted into a duct or container of circular cross-section and to be sealed therein by means of the flexible leaf seals 36.

In the case of the filter shown in Figure 2, the end rings 32 and 34 in Figure 1 are replaced by ring seals 38 and 40 made of neoprene or some other rubbery material. The Figure 2 form of filter is therefore suitable in those instances where the outer casing 10 does not need to lie within a duct or other container.

In order to allow the two filters shown in Figures 1 and 2 to be used in any desired orientation, the axes of the cells of adjacent cellular layers 24 and 28 lie at different angles to the vertical and also extend in different directions when the cellular layers are viewed from above or below. To make this more clear, Figure 3 illustrates the way in which the six cellular layers 24 or the six cellular layers 28 in both Figures 1 and 2 have their cells extending at different inclinations with respect to the vertical. In addition, the axes of the cells extend in different directions when the cellular layers are viewed from above or below. By way of example, the axes of the cells in two adjacent layers of cellular material can make an angle of 1500 with respect to each other, while the directions in which the cells of those two layers extend when viewed from above or below can be at an angle of 450 to each other. It thus follows that, whatever the orientation of the filter, the activated-carbon particles in the cells of the cellular layers 24 and 28 will be able to ensure that no fluid passes through the filter without being scrubbed by either particles in the cellular layers 24 or else particles in the cellular layers 28.

Claims

1. An activated-carbon fluid filter comprising spaced-apart inner and outer casings each having a through-passage for the flow of fluid (usually air) through the filter in separate streams, in which the inner casing has a body portion and a neck portion, which body portion supports within itself and over its entire cross-section a number of adjacent layers of cellular material with activated-carbon particles in their cells for the removal of noxious substances from fluid passing through the inner casing, while the outer casing cooperates with the neck portion of the inner casing to support other layers of cellular material likewise having activated-carbon particles in their cells, the said layers being arranged to bridge entirely the gap between the outer casing and the neck portion of the inner casing for the removal of noxious substances from fluid passing through the outer casing.

2. A fluid filter according to claim 1, in which the axes of the cells in adjacent layers of cellular material extend in different directions when the layers are viewed from above or below so as to allow the filter to be used in any desired orientation.

3. A fluid filter according to claim 1 or claim 2, in which the ends of the cells in the cellular layers are closed by screens which are bonded to the cellular layers bythermoplastics coatings on metal mesh supports.

4. A fluid filter according to any one of claims 1-3, in which the ends of the outer casing have end rings or caps provided with flexible leaf seals to allow the outer casing to be inserted into a duct or container and to be sealed therein by the flexible leaf seals.

5. A fluid filter according to any preceding claim, in which each assembly of cellular layers comprises six such layers.

6. A fluid filter according to any preceding claim, in which the axes of the cells in two adjacent layers of cellular material are at an angle of 450 with respect to each other when the cellular layers are viewed from above or below.

7. A fluid filter substantially as described herein with reference to Figures 1 and 3 or Figures 2 and 3 of the accompanying drawings.