The hot water used in the factory production process is drained as wastewater, which contains a large amount of heat energy. Countries are now beginning to study technologies to recycle hot wastewater in factories or into residential areas. Imperial Brewing Company of Japan has reduced the fuel consumption of boilers by 70% by recovering hot waste water from washing wine bottles and recycling it in the bottle washing process. The bottle washing process is to first use a conveyor belt to send the empty bottles into the bottle washing machine. Pre-wash with 40°C warm water, then formally rinse with 60°C hot water, and finally pass in 110°C steam for sterilization. Since the hot water used to rinse the outside of the wine bottle cannot be recovered, 1 ton of water needs to be replenished every hour. In the past, 12 tons of new well water were needed per hour, but now the water consumption is only 1/12 of the past.
Sakamoto Industrial Co., Ltd., which produces automobile mufflers and fuel pumps, has designed an energy-saving and resource-saving "hot wash high-pressure injection device." This device uses high pressure to spray 70°C hot water onto the pressed fuel tank, washes away the pressed oil, and then recovers the hot water for reuse. In the past, a milky detergent was used to flush the press oil, which was difficult to reuse. However, after using hot water to flush the press oil, the hot waste water can be recycled. This alone saves the company 3 million yen in energy costs a year.