ABEL EM & CM – PVC production

The application

Our customer is europe’s largest fully integrated polyvinyl chloride (PVC) production plant in Germany. The plant produces the plastic material po­lyvinyl chloride (PVC) using ethylene and salt as raw ma­terials with intermediate products ethylene dichloride and vinyl chloride.

In 2002, ABEL supplied its first electromechanical dia­phragm pump for pumping polyvinyl chloride dispersions to the customer. Today, a total of nine electromechani­cal diaphragm pumps as well as two piston diaphragm pumps are operating in the PVC production plant.

The ABEL solution

Between 2008 & 2010, two quadruple type EM 125 elec­tromechanical diaphragm stainless steel pumps in ATEX design have been used in the production plant in parallel installation. The pumps transport flammable PVC disper­sion with vinyl chloride content of 5 to 10% from chemi­cal reactors into buffer containers. Originally, the reactor pressure of ca. 6 to 8 bar was used to transport the PVC dispersions into the buffer container. Due to the use of the electromechanical diaphragm pumps whose original pumping pressure is 0.5 bar, the time for emptying the reactor has been clearly reduced. This makes it possible to fill the reactor faster.

The pumps are equipped with ABEL intelligent diaphragm (Membrane) Pulsation Dampeners (iMPD). Our special construction has proven to be useful where minimal resi­dual pulsation needs to be achieved when pumping pres­sures fluctuate. Conventional diaphragm pulsation dam­peners are pre-charged for a certain pumping pressure and offer optimal dampening only in a relatively narrow range around this pumping pressure. The ABEL iMPD automatically adjusts the charge to the pumping pressu­re, so that dampening occurs in a much wider pressure range with consistently reliable results.

In a different area of the plant, an ABEL piston diaphragm pump of the CM series has been in continuous operation for loading a dryer plant since 2011. This pump is also made from stainless steel and is ATEX compatible. The pump transports hot PVC dispersions of temperatures up to 70°C and with a content of solid matter of 40 to 55 % to a spray dryer. Operating pressures between 8 and 20 bar are necessary due to various quality requirements. Therefore, the pump is equipped with two conventional diaphragm pulsation dampeners with different pre-char­ge settings.