Concn. of milk etc. by evapn. using mechanical vapour compression - with common drive shaft for separate compressors serving two evapn. stages

摘要

The installation is of the type which employs a reconcentration stage, comprising a single or multiple effect evaporator, in series with a final concn. stage, comprising a single or multiple effect evaporator. Both concn. stages are equipped with mechanical compression of exhaust vapour. Vapour from the final effect of the preconcentration stage is directed to a first mechanical compressor which supplies the first effect heater of the preconcentration stage. Vapour from the final effect of the final concn. stage is directed to a second mechanical compressor which supplies the first effect heater of the final concn. stage. The two compressor rotors are mounted on a common drive shaft. The second compressor which supplies the final concn. stage pref. has a higher compression ratio than the first compressor serving the preconcentration stage. Only a single drive motor is required for compressors serving both the preconcentration and final concn. stages.