Improving mechanical sepn. of solids in communal waste water treatment - by treating water with flocculating agent in an agitated pressure vessel and conveying by pressurised gas supply to filter press separator

摘要

Liq. is treated with a flocculating agent before being mechanically sepd.. The treatment process is carried out shortly before the sepn. stage and takes place in one or more pressure vessels from which the liq. is conveyed by a compressed gas supply to the sepn. equipment. A finely-divided air supply is applied to the pressure vessels during the addn. of the flocculating material. The gas pressure is increased during sepn. equipment, and the remaining pressure in each vessel which has been emptied is used to start the proces in the following vessel. A pump may be used to fill and to build up the initial pressure in the pressure vessel and the filter press before the compressed gas supply is applied to raise the pressure to its required final value. USE/ADVANTAGE - This invention is used for optimal sepn. of solid particles from liqs. such as is required in the chemical industries for the recovery of prod. particles, or in the purifcn. of waste waters. The mechanical sepn. of finely divided, colloidal and widely dispersed solids by means of filter presses, centrifuges, rotary drum filters, or vacuum drum filters, after treatment with a flocculating agent, is improved by increasing the percentage of the solid particles which is retained in the filter cake.