GB850808A - Improvements in or relating to temperature controlling apparatus - Google Patents

Abstract

<PICT:0850808/III/1> An apparatus to control the temperature of equipment, e.g., an autoclave, a column reactor or vessel, a vat or the extrusion machine of Specification 815,485, comprises at least one heat exchange zone 2 which may surround or pass through said equipment containing vapour and its condensate, means 3, 4 to supply vapour automatically to said zone 2 and to maintain a constant pressure therein, means 6 operated by the pressure within said zone 2 or the temperature within said equipment to interrupt the supply of vapour, means 8 to condense the vapour supplied to said zone, means to return the condensate to the zone and means 7 to remove excess of condensate from the zone. Steam is supplied through a reducing valve 4 to a jacket 2 of, e.g., an autoclave 11 having a condenser 8 and an overflow pipe 6 with steam trap 7. In operation, steam at a constant pressure enters the jacket, bubbles through the condensate, is condensed by the condenser and the rise in level of the condensate causes overflow through the pipe 6 and trap 7 to maintain a flow of steam at a constant pressure and hence temperature. If heat is absorbed by the autoclave the condensate takes heat from the steam, causing the pressure to be reduced and thus more steam to be admitted to maintain constant the pressure and temperature. If the autoclave gives out heat the condensate vaporises, causing the pressure to rise and the reducing valve to supply less steam and thus maintain constant the temperature and pressure. The reducing valve may be replaced by a source of steam at constant pressure or a temperature-sensitive valve, controlling the input of steam, may be placed in the jacket. The excess condensate may be removed by an ejector, operated by the condenser, in place of the overflow and trap.