An original equipment manufacturer specialising in road sweepings, gully waste and interceptor waste recycling have been using Pinch Valves from AKO UK within their oily sand/sludge equipment.
Sand washing is ineffective once the particles are below 50 micron. At this point the material becomes an oily sludge. The recovery of oil and cleaning of solids within the sludge now requires a chemical and heat treatment.
The OEM have been cleaning oil contaminated sand for many years. Their treatment plants deliver 120t+ per hour of oil contaminated sand. The technology has been greatly improved over the years, but the core principles remain the same:
The Pinch Valve follows a sand cleaner holding material back at a static head of 10m, and releases clean, ambient sand from the base of an up-flow classifier which floats off oil and fines. The valve is installed vertically, in the normally closed position under an up-flow classifier. The operating pressure is 2.5bar.
The up-flow classifier is an effective device in solving the problems of gravitational methods of enrichment of quartz sands.
VF model, air operated, aluminium body, aluminium flanges PN10/16 with mild steel bushing contact parts, natural rubber sleeve.
The OEM have been using suitable Pinch Valves for washed sand in this application for three years. The Engineering Director from the company told us:
“It is the best valve for continuous removal of sand in this application, and seems very good so far.”
The Engineer has many years of experience with chemicals and so he has used plenty of knife gate valves – actuated (spring return) and manual (lever), plus ball valves and butterfly valves. He explained to us at AKO UK that the technology of the Pinch Valve is like no other, performing as a highly recommended valve solution for sludge applications.
The Pinch Valve on this particular sand washing machinery has recently been replaced, but prior to that it was not changed in two years.
There is future potential for more Pinch Valves for washed sand to be used by this company as they might manufacture and sell units to other companies. The current operating company is a sister company.
