How water wastage was blown away on a production line in China
Purmo Group has a radiator plant in Yangzhou China which manufactures approximately 340,000 radiators per year, principally the H300, H600 and H900.
Every radiator that comes off the production line has been through a pre-treatment tank (PT) and ultrafiltration flushing (UF). Pre-treating and flushing radiators is an important part of the production process as it is essential that, prior to painting, the radiators must be completely clean and free from any oils or residues.
These two processes consume a lot of water, which becomes contaminated as it is used. Once the radiator has been pre-treated and flushed this ‘waste’ water is transferred into an electrophoresis tank (ET). This is a commonly-used technique to essentially separate different molecules in the contaminated water based on their size, and involves using further chemicals. The waste water must be treated carefully and safely before it is released back into the environment.
Reduce, Reuse, Recycle
The production team researched possible solutions to the problem and, inspired by a similar production line at the Rybnik plant in Poland, they hit upon the idea of simply blowing away the waste water.
Air blowers were installed above the tanks, and now as the radiators emerge from the water, the excess water is blown straight back into the tanks, where it can be re-used. Less water is used, the ET tank is uncontaminated and there is less dirty waste to treat and dispose of.
In a full year, over 100,000 kg of water is directed back into the PT tank, and over 60,000 kg into the UF tank. The cost of installation of the blowers was recouped within four months, due to the decrease in costs of treating the contaminated waste water.
Colin Wang, Environment & Safety Engineer at Yangzhou plant said: ‘The installation of the blowers has been a resounding success. The environmental benefits are huge, with a significant decrease in water usage, the amount of contaminated waste water we need to deal with, and also the reduction in the chemicals we need to use. And as the investment paid for itself within four months, it made sound business sense as well. It really is a win-win solution.’