The Problem

A hot die casting company sprays a special high temperature release oil into their molds to facilitate removal of the finished injection molded parts. This mold release oil has an odor and produces smoke, which is exhausted to a special water curtain air filter. Dust particles and airborne oil particles are removed by the water curtain which falls into a holding tank, where they coagulate and float on the water surface. The high temperature mold release oil has a high viscosity, and at room temperature it is very sticky. When the dirt particles and the oil mix, it forms a heavy sticky sludge layer on the water surface. Different oil sludge separation systems had been tried, but they were incapable of removing this type of sticky sludge, and the machines were clogged in a short time.

The Solution

The FRIESS Model W40 with oil collector tube was able to remove the dirt, fat and oil from the whole water surface of the tank. The floating oil collector tube’s movement results in turbulence on the water surface which causes the surface sludge to move away from the corners of the tank, where it is then easily captured by the oil collector tube. The removed dirt, oil, and fat sludge is very viscous and doesn’t flow. It was therefore necessary to mount the FRIESS Model W40 Oil Skimmer system on a bracket on the outside of the water tank, so that as the scrapers removed the sludge from the oil collector tube, the sludge could drop straight down into the open oil/sludge container. The design and construction of the FRIESS Oil Skimmer guarantees that the oil skimmer cannot be blocked or clogged by such sludge or debris mixed with oil. No maintenance is required during operation.

The Result

The curtain water which leaves the settling tank is nearly oil free, and it can be continually reused. The only wear item is the oil collector tube that will require replacement after 2 to 3 years of continuous operation. No maintenance is required for the oil skimmer.