AQ4/3/4/2

Longitudinal section arrangement drawing of steam turbine. Note from Mr Curtis identifies it as ‘a backpressure set ordered for Sketchly dye Works, Hinckley in October 1932. the design steam conditions were inlet 200 psig 538 oF, exhaust 50 psig (back pressure). the output was 400 kW + 25% overload. The set was designed to run at 8000 rpm and the gearing drove the alternator at 1500 rpm. this set has a solid rotor and labyrinth glands at all points. It also appears to be fitted with the McLeod patent moisture excluding baffle. It is of non-condensing (back pressure) set. Thus there are only the 2 oil pumps to be driven from the free end of the shaft. These important detail differences in design taken with the very different style of the two drawings pint up the almost complete separation there was reported to be at that time in Allen design as between Naval and commercial work. The drawing number and date have been deliberately masked when making this print, presumably so that it could be shown to another potential customer as a typical design. The emergency valve and the main control valve rely on oil pressure for operation and are of a generally similar layout to designs used later. However the relay valve is mounted on the side of the operating cylinder and is connected to the governor by rods and levers. In addition there are 3 hand operated nozzle control valves and a fourth, similar hand operated bypass valve. The governing system appears to represent an interesting hybrid intermediate design between the old style lever governor with throttle valve control and the later ‘leverless’ all-oil-relay operated system. The system of separate hand operated nozzle valves downstream of the main throttle valve operated by the governor was never very satisfactory as it relied on the operator opening and closing such valves as the load passed from one band to another. The later systems obviated these problems.’

1932

From: 1932 To: 1932

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drawings, steam turbine, Hinckley, BEDFORD