Heat recovery from warm waste water at dyeing process by absorption heat pump

Abstract

In Japan, technology for energy saving is the primary subject in many factories and buildings, and exhaust gas heat recovery and hot water recovery are practiced popularly. In textile dyeing processes, bottle washing processes and in public baths, a large quantity of warm water, 293–323 K, is discharged but almost all of such water is discarded because the temperature is low. In October, 1980, we completed a system to recover the heat of 1.39 × 10 9 J h −1 out of the waste water from dyeing process of 303–323 K discharged at the rate of 60 m 3 per hour using an absorption heat pump, and obtain the hot water at 353 K in the rate of 3.48 × 10 9 J h −1. The system was installed at a textile dyeing plant. The details of the system and the effect of energy saving during operation are reported below.