Method for cooling a heating apparatus

A method of cooling a heating apparatus comprising a heating chamber, the method comprising:

• accumulating condensate in the heating chamber;
• monitoring a pressure in the heating chamber;
• controlling the pressure in the heating chamber by venting the heating chamber in a first phase to thereby controllably permit vaporisation of the condensate that cools the heating chamber;
• and
• activating a pressure reducer in response to reaching a threshold pressure, to reduce the pressure in the heating chamber below the threshold pressure in a second phase, in order to further control the vaporisation of the condensate;
• wherein the pressure is controlled to maintain a rate of cooling of the heating chamber within a predetermined range,
• wherein the heating chamber is vented through a vent valve, and wherein the pressure reducer is a thermocompressor which is activated by opening a motive valve connecting a vapour supply to a motive inlet of the thermocompressor, and wherein the heating chamber is connected to a vapour inlet of the thermocompressor via the vent valve.

A method of heating and cooling a heating apparatus comprising a heating chamber, the method comprising:

• accumulating condensate in the heating chamber;
• monitoring a pressure in the heating chamber;
• controlling the pressure in the heating chamber by venting the heating chamber to thereby controllably permit vaporisation of the condensate that cools the heating chamber;
• and
• draining condensate from the heating chamber via a condensate line;
• wherein the pressure is controlled to maintain a rate of cooling of the heating chamber within a predetermined range;
• wherein accumulating the condensate comprises receiving vapour from a vapour supply, condensing the vapour in a heat exchanger and supplying the condensate to the heating chamber;
• and
• wherein the vapour supply is the same vapour supply as is used in a previous heating operation to heat the heating apparatus.