Integrated mechanical vapor recompression apparatus and process for the

Abstract

Disclosed are a method and apparatus for selectively generating different amounts of electric power and high pressure steam power according to the user's needs, using a fluid-cooled engine and a dual-function screw machine that may be operated as either a compressor or an expander. Fluid from a cooling jacket fluid is separated into vapor and liquid portions and, to increase the amount of high pressure steam delivered by the apparatus, low pressure steam from a separator is compressed by the screw machine and liquid from the separator is heated to a high temperature and high pressure. When additional electric power is desired, the low pressure steam from the separator is diverted from the screw machine. High pressure steam, manufactured by compressing and heating the liquid of the separator, is expanded in the screw machine, which adds its power to the main drive shaft, thereby adding to the available electric power. Various combinations of amounts of electric power and steam power are possible by controlling the amounts of material presented to the screw machine as either a compressor or an expander. The apparatus also includes a recirculation system used when the screw machine is employed as a compressor during periods of off-design point engine load and which facilitates driving the screw machine without drawing down the pressure of the apparatus.