Document KRVNep7gGxMMBjmvbDVxkpBxx

lii.2. available* In operation, duet-ladenair is drawn into the filter* the duet is retained and the dean air passed on | J > j through to the fan. This is your fan motor set; this is . your hose; this is your filter paper holder* We just set it on an ordinary engineer's tripod so that we can carry .' it around at the same time keep it up in the air, and the ! 1 filter paper holder section is here. It was a simple metal! affair. It had a screw cap on it and the filter paper was : held in position there tightly. Now, we're not sure about the efficiency of col lection of this device, although we know it's very high. Through experience, we have learned, for example, that we can run this thing all day In a coal mins, collection a i ! I j -- collect a deposition on the filter which would be on this side, heavy enough to completely fill up all the cleats, and yet when we take the filter paper off, the back of the . filter the color of the back of-the filter hasn't caanged at all, that is If any particles did pass through, there were yery few of them, so that the paper must be an effic ient collecting device. The device was employed for collecting the air Lborne dusts from coal face operations, from workings in roc and during the coal train haulage. Figure two illustrates j a typical section through a coal formation of two of ine SEVENTH SARANAC -0169