Hi,
Each machine has it's individual operation cheq. curve.It is depended on the inlet condotion, outletcondition of steam.It means temp,& pressure, Purity of steam, Vacuum in condenser ,if condensing turbine. For the back pressure turbine efficiency depend upon the backpressure, inlet...
For the Mechanical terms Back pressure turbine is that produce Electrical powerand some steam which is extracted form the turbine isused for the process purpose. In some process like paperIndustries,Petrochemical Ind. Soda ash Ind.they have required steam for the process purpose& they have...