. Electric railway journal . less of multi-plicity of franchises, owners and operating companies. March 12, 1910.] ELECTRIC RAILWAY JOURNAL. 459 A NEW HORIZONTAL IMPULSE TURBINE The accompanying illustrations show the details of theBergman turbine, as built by Dick, Kerr & Company, Lim-ited, London. This machine is of the impulse type andfrom five to fifteen pressure stages or chambers, with thesame number of wheels, are employed, according to the sizeof the turbine. In the first chamber the principle of velocitystages has been adopted. Here the steam is allowed to ex-pand from a working press
. Electric railway journal . less of multi-plicity of franchises, owners and operating companies. March 12, 1910.] ELECTRIC RAILWAY JOURNAL. 459 A NEW HORIZONTAL IMPULSE TURBINE The accompanying illustrations show the details of theBergman turbine, as built by Dick, Kerr & Company, Lim-ited, London. This machine is of the impulse type andfrom five to fifteen pressure stages or chambers, with thesame number of wheels, are employed, according to the sizeof the turbine. In the first chamber the principle of velocitystages has been adopted. Here the steam is allowed to ex-pand from a working pressure of 150 lb. to a pressure offrom 15 to 45 lb. The wheel moving in this chamber car-ries two series of blades separated by a set of stationaryreversing blades. This construction eliminates high pres-sures and temperatures from the rest of the turbine bodyand simplifies the problem of sealing the turbine from theatmosphere and between the stages. An ingenious laby-rinth device is employed as a seal in the first Rotor for Dick, Kerr Turbine The body of the turbine consists of a single cast iron cyl-inder, split horizontally in the center. At the admission endthe cylinder is closed by a cover in one piece, which in thecase of the smaller sizes of machines is made of cast iron,and in the larger machines of cast steel. No special coveris required on the exhaust end. The body is supportedfreely on one support, which surrounds the vacuum end of the section of which increases from the narrowest part tothe end. From 10 to 20 such nozzles are placed togetherand form a nozzle segment, and this latter forms the firstset of guide blades, which is set immediately behind thethrottle valve and regulates the admission to the velocitywheel. This segment is made of bronze, and is fastened toa casting of steel so as to be quite steam tight. The castinghas a flange for connection to the high pressure steam sup-ply, and there are two handles for operating two valves, bymeans of which a c
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Keywords: ., bookcentury1900, bookdecade1900, bookpublishernewyorkmcgrawhillp
