New autoclave uses compact process valves to meet cost and performance targets

29 April, 2015

The ESTS exclusive design employs ceramic heating elements cast into a solid aluminium heater matrix. The unit attains operational temperature in a matter of seconds and converts water into steam on an on-demand basis, rather than maintaining a pressure vessel reservoir. An average usage cycle consumes just 10kWh which ESTS estimates will provide a 50 per cent reduction in energy costs.

In order to guarantee savings in the total cost of ownership, the valves that control the fluid and steam in and out of the heater have been adapted to cope with the high temperatures. There are two actuated ball valves being used – one to control water flow into the header tank and another to drain the flash steam generator of any residual fluid; this has an extension piece to keep the heat transfer to a minimum to protect the actuator which inherently has a lower temperature protection rating than an angle seat valve.

The lack of a conventionally heated pressure vessel boiler in the machine is a crucial aspect in the reduced maintenance cost calculations, as they are subject to comprehensive legal service and inspection procedures. The physical cost of these checks amounts to over £1000 on a bi-annual basis, plus the cost of two days of operational downtime. Experience also shows that immersed elements either in chamber or when fitted to conventional electrically heated steam boilers are prone to failure with typical costs associated with replacement at well over £1000.

www.burkert.co.uk