Documenting the filtration process for various slurries.
Industrial / Sponsored Film; Promotional; Science and Technology
To establish the importance of separation solids from liquids, the film begins with an everyday situation of a man drinking in a pub. It highlights a variety of everyday products, including scotch, sugar bottles of cider coming off a bottling line, a nurse giving medicine and agricultural machinery at work. The commentary emphasises that all of these need separation or filtration. There are brief shots of filtration processes and then of a river, to emphasise how important it is that effluence is clean.
The film shows the work of Davey, Paxman & Co. Ltd. This begins in the laboratory and the pilot plant where samples of slurry are tested. There are shots of the process. There is a brief shot of Kings College, Cambridge University and then interior shots of a laboratory of the Chemical Engineering Department. There is a brief external shot of the Department of Scientific and Industrial Research. The film uses a case history, that of a marble mason, to explain its work further. There is a shot of marble sludge that has caused a disposal problem as it has blocked drains, causing problems for the mason and his local authority. To begin with the company propose a settling pit and there is a shot of this. However, this proves uneconomical.
The next stage is to try filtering. Samples are tested in the laboratories and pilot plant at Colchester. There are scenes from the design office and a still of the drawing they produce. The sequence finishes with shots of the machinery in action.The next sequence shows some of the range of filters the company produces. The commentary emphasises that there are different filters for different solid contents. There are scenes from the manufacture of paper and the processing of coal. The spray wash gear is used in the food and pulp industries.
Where chemicals are involved, filters are made from stainless steel, aluminium or lined with rubber. PVC is used where chemicals cannot come into contact with metal. Scenes from a cider manufacturer show he continuous pressure filter in use. Shots of a new housing estate precede a sequence showing how filters are speeding up the treatment of sewage and there are shots of men at work on a sewage farm. Firstly the dry bed method is shown and this is contrasted with the new filters. The film ends with a montage of shots of its subjects.
Davey, Paxman & Co. Ltd.
University of Cambridge; Department of Scientific and Industrial Research Water Pollution Research Laboratory