PLC Based Removal of Medium Sized Particles using Dump Valve
In the pulp processing, screening equipment is one of the essential operational system. Fiber is separated from the black liquor of the pulp within the washing segment comprises of foreign matter, coarser fibers and brick pieces of bark. Hence in the pulp screening equipment the unwanted and troublesome matters need to be removed for supplying first quality pulp. Typically, it requires several hours (1.5 hours) at 170 to 176 °C (338 to 349 °F) this makes the process even worse for exposure. In the junk trap process instead of controlling it manually a Programmable Logic Controller (PLC) can be used to automate these control valves and drain the medium sized particles. It should be done by opening and closing both the valves automatically for a certain period of time. When the pulp enters the junk trap the first valve will be opened and the second valve will be closed so that the medium sized particles settle at the second valve. After some calculated time the first valve gets closed and second valve gets opened so that those particles are sent to the rejection tank. After some time second valve will be closed again and the first valve will be opened so that it continues for the second cycle. This paper is proposed to control and monitor the valves automatically in the junk trap.
Keywords: Control valves, Flow sensor, PLC, Pulp, Screening, Temperature .