It is a requirement for metalworking industries to employ mist collectors when using machining tools in order to make sure that the air around the work area is clean. It is also to decrease any negative effect that the emissions could have on the fluids used in metalworking. There is a standard that must be observed especially in the quality of the indoor air thus it is important to use mist collectors. It also aids in decreasing the costs incurred during maintenance and housekeeping as well as improving the quality of the components manufactured. The process of mist collection has a lot of benefits to the metalworking industry but their challenge lies in choosing the right kind of mist collection machine because there are a wide array of choices.
Mist can be simply defined as a droplet in liquid form with a diameter of 20 microns or smaller. Though there are many applications wherein mist collection is employed, this will focus mainly on the ones that are utilizing lubricants and coolants that are oil-based as well as water-soluble. The lubricants and coolants are known to be used in various applications in the metalworking industry such as parts washing, metal cutting, grinding and metal forming, among many others. One excellent example is a water-soluble substance that is used in operations such as milling and turning which in turn releases mist droplets that have diameters ranging from two to twenty microns. The same scenario but this time with the use of an oil-based substance will emit mist droplets that have diameters ranging from 0.5 to 10 microns.
Smoke is much smaller in diameter with only a range of 0.07 to 1 micron. It can be in the form of solid or liquid and is a byproduct of combustion or condensation processes involving supersaturated vapor that were not finished. The smoke is also referred to as oily smoke or mist that is thermally produced. Most common applications that produces smoke includes heat treating, cold heading, machining that uses straight oil on the hard metal and large generators that make use of lube oil reservoirs.
The main function of mist collectors is to make sure there will be no smoke as well as mist left on the air that has undergone filtration. This is done by transforming the smaller droplets into larger sizes before the coolant that was collected is drained. There are three properties that affect how a mist collector operates:
- Flow rate. The collector’s flow rate is essential because it is the one indicating the amount of air that can be filtered. The rate of the airflow must be constant to make sure that the efficiency of capturing droplet is maintained at a desirable condition.
- Efficiency. This characteristic is vital because it indicated how clean the surrounding atmosphere once the air is released from the collector and out into the indoor air.
- Pressure drop. This is an important component of the equation used in energy cost. The higher the number of the pressure drops could indicate that a higher energy is also needed to create the necessary airflow that will pass to the collector system.