Some Engineering Features of the Weymouth Station of The Edison Electric Illuminating Co. of Boston

The new power station of The Edison Electric Illuminating Company of Boston, now under construction on the Weymouth Fore River is expected to have an ultimate capacity of about 300,000 kw. The present construction covers the installation of two 32,000 kw. generating units with three 1974-h. p. boilers, operating at 375 lb. steam pressure and 700 deg. fahr. In addition, a single boiler to carry steam at pressures up to 1200 lb. is to be installed. This boiler will have about the same heating surface as the normal pressure boilers. The steam generated by it will pass through a pressure reducing turbine developing about 2000 kw., and will be exhausted at 375 lb. pressure. After being reheated to the original temperature of 700 deg. the steam will be piped to the main header and used in the large turbines. If satisfactory results are obtained from the higher-pressure boilerturbine units more of them will be installed. Three will be required to furnish sufficient steam to operate one of the 32,000-kw. units. The maximum steam temperature was fixed at 700 deg. in consideration of the properties of materials at the higher temperatures. While the theoretical gain from higher pressure increases up to the maximum for which any data are available, the full benefit of the thermodynamic possibilities are not at present obtainable in practise without reheating the steam at some point intermediate between the throttle and the condenser.