GB180699A - Arrangement in steam plants with steam accumulators and back pressure- or condensing steam motors - Google Patents

Abstract

180,699. Aktiebolaget Vaporackumulator. May 30, 1921, [Convention date]. Automatic gear.-In a steam plant in which exhaust steam or steam from an intermediate stage of a turbine &c. is used for other puposes, the flow of steam being regulated by an accumulator, a reducing valve is arranged between the accumulator and the low-pressure line in order to permit expansion in the turbine to below the accumulator pressure. A non-condensing turbine C, Fig. 3, driving a generator D, exhaust into a low pressure line G, supplying paper machines &c. H. If the pressure in the line drops, a valve J opens and supplies steam from an accumulator F. The latter is supplied from the boilers A and high-pressure line B through pipe lines L, N controlled by valves M, O. The valve M is controlled by the pressure in the line B and opens if the supply pressure rises, while the valve O is controlled by the pressure in the accumulator line K and opens if the accumulator is discharged. If high-pressure steam consumers P are connected to the line B, the turbine is further governed by valves Q, R and a speed regulator S. The valve R is governed by the pressure in the line G and opens if that pressure falls. Fall of pressure in the line B is, however, prevented by the valve Q which is governed by the pressure in the line B. The regulator S acts only at excessive speeds. In a modification the valve Q is placed between the line G and the point from which the governing steam for the valve R is taken. Fall of pressure in the line B closes the valve Q and the consequent rise in pressure of the governing steam of the valve R causes that valve to close. In another modification the valve R is dispensed with and the valve M is governed by the pressure in the line G. If that pressure falls, the valve M opens and admits steam to the accumulator F. The arrangement shown in Fig. 3 may be modified by the addition of a low-pressure condensing stage to the turbine, which is supplied from the line G under the control of a speed governor. In a modification, shown in Fig. 7, the low-pressure stage U of the turbine, exhausting into a condenser V, is supplied with steam under the control of a valve Z. If the pressure in the line G rises, the valve Z admits more steam to the stage U and the increased speed causes the governor S, operating at normal speeds, to throttle the supply to the stage T. If the pressure in the line G falls, the valve Z closes, thus admitting more of the exhaust from the stage T to the line G. The consequent reduced turbine speed causes the governor S to admit more steam to the stage T, thus further increasing the supply to the line G. Fall of pressure in the line B causes the valve Q to restrict the supply to the line G without reducing the turbine speed. Fig. 8 shows an arrangement with three turbine stages Y, T, U, in which an intermediate line B<1> supplies the turbine stages T, U, steam consumers P<1>, the accumulator line K, and low-pressure line G in a manner similar to arrangements described above. The line B<1> is supplied by the exhaust from the high-pressure stage Y and from the high-pressure line B under the control of valves M, O. Specifications 135,474, [Class 64 (ii), Heating systems &c.], 135,478, and 178,081 are referred to.