Mass finishing processes are most usually wet processes. The water used in the vibratory or tumbling process contains abraded media, compound and particulate from the work pieces themselves. Some processes will be set up as a closed drain process in which the water is circulated through the machine during the cycle. This method uses less water, but the water eventually will be flushed out of the system. The other method is an open drain, or flow through process in which fresh water and compound are metered into the mass finishing equipment while processing. Either of these systems will eventually require dealing with wastewater, referred to as effluent, at some point. In a closed drain system, this will happen at the end of the process or batch and in a flow through system the effluent will need to be dealt with continuously. Occasionally the effluent is transferred to a settling tank or lifting station until it can be processed.
The two basic classifications of equipment that deal with effluent, or wastewater, is via a Filtration System or a more sophisticated Centrifuge System.
Municipalities differ significantly as to what might be able to go directly to drain. In almost all cases effluent must be treated prior to going to drain. Abrasive Products recommends that you always check with your local municipality as to what can safely be disposed of via drain. Properly dealing with effluent is a critical consideration in determining what process works best for your application.