GB1348894A - Chemical toilet system - Google Patents

Abstract

1348894 Chemical closets BRITISH RAILWAYS BOARD 13 Jan 1972 [20 Jan 1971] 2793/71 Heading E1C A chemical toilet system, particularly for a railway carriage, comprises a toilet pan, a cistern for supplying flushing water to the toilet pan, a waste outlet arrangement extending from the toilet pan to a discharge outlet, the arrangement including a water trap followed by a slurrying device, and means for dispensing a treatment chemical into the waste outlet arrangement at a position downstream of the water trap and upstream of the slurrying device. In one embodiment, Fig. 2, waste from two water-flushed toilet pans (4, 5, Fig. 3, not shown) passes first to a holding tank 8 which is dosed with a predetermined quantity of treatment chemical, each time one of the pans is flushed, by solenoid valves 17a, 17b associated with a storage tank 13, for treatment chemical, and a measuring chamber 14. When the holding tank is full, a level-sensing switch (not shown) switches on a macerator 10 which feeds the sewage in the form of a slurry to a storage tank 9 of larger capacity than the tank 8. The treated sewage is discharged from the tank 9 on to the track via a discharge pipe (11, Fig. 3, not shown) which is open during travel between stations but is closed off by a valve, either manually or automatically by a speed sensing control, when the train is standing in a station. A dumping valve 12, operable by an attendant or automatically, is provided on the tank 8 for emergency use where the tank 8 has become overfull due to a blockage in the system or malfunctioning. In a second embodiment, Fig. 6, the holding tank 22, which may be used with or without a storage tank 9, has a chemical dispensing valve 26 mounted directly on it, in addition to a macerator 24, driven by a motor 25, and a sliding weir outlet 29 operated by a handle 30 for dumping.