Patent GB-498634-A (GB)
Title: Improvements in oil filters
IPC: B01D39/20
Filed: 1938-03-11
Abstract: An oil-filtering material consists of a nodulated mineral wool mixed with a casein binder.  In preparing the material, a typical mixture is as follows: 43,4 per cent by weight of mineral wool, 52,6 per cent of water, 1,03 per cent of ammonium hydroxide, 1,25 per cent of formaldehyde, 1,72 per cent of casein.  The ammonium hydroxide is for dissolving the casein and the amount used will depend on the size of the casein grain.  After mixing, the material is formed into the desired shape and dried, for example, in an oven.  The parent Specification is referred to.  According to the Specification as open to inspection under Sect. 91, solvents other than ammonium hydroxide may be used, e.g. a mixture of 20 per cent of commercial borax and 80 per cent casein has been found satisfactory.  A water soluble casein may be used, this casein being rendered insoluble by the reactions with the other ingredients.  The formaldehyde may be replaced by a number of other substances which increase the resistance of the casein to water solution, e.g. by salts of chromium, tannic acid, aldehydes other than formaldehyde.  In preparing the mixture, the casein is first dissolved in hot water to which ammonia has been added. formaldehyde is added and then the nodulated mineral wool. The mass is mixed in a rotating bowl for about four minutes and is then shaped.  The shaped units are placed on perforated metal trays about one-half inch apart and dried in a steam drier for about six hours at a temperature of from 300-325 DEG  F. Alternatively, the shaped units may be subjected to an initial temperature of 500 DEG  F., which is reduced to 375 DEG  F. for the latter part of the drying period. This subject-matter does not appear in the Specification as accepted.ALSO:An oil-filtering material consists of a nodulated mineral wood mixed with a casein binder.  In preparing the material, a typical mixture is as follows: 43,4 per cent by weight of mineral wool, 52,6 per cent of water, 1,03 per cent of ammonium hydroxide, 1,25 per cent of formaldehyde, 1,72 per cent of casein.  The ammonium hydroxide is for dissolving the casein and the amount used will depend on the size of the casein grain.  After mixing, the material is formed into the desired shape and dried, for example in an oven. According to the Specification as open to inspection under Sect. 91, solvents other than ammonium hydroxide may be used, e.g. a mixture of 20 per cent of commercial borax and 80 per cent casein has been found satisfactory.  A water-soluble casein may be used, this casein being rendered insoluble by the reactions with the other ingredients.  The formaldehyde may be replaced by a number of other substances which increase the resistance of the casein to water solution, e.g. by salts of chromium, tannic acid, aldehydes other than formaldehyde. In preparing the mixture, the casein is first dissolved in hot water to which ammonia has been added, formaldehyde is added and then the nodulated mineral wool.  The mass is mixed in a rotating bowl for about four minutes and is then shaped.  The shaped units are placed on perforated metal trays about one-half inch apart and dried in a steam drier for about six hours at a temperature of from 300-325 DEG F. Alternatively, the shaped units may be subjected to an initial temperature of 500 DEG  F. which is reduced to 375 DEG  F. for the latter part of the drying period.  This subject-matter does not appear in the Specification as accepted.