At Meadow Foods' Holme on Spalding Moor plant in Yorkshire, the chocolate crumb production lines had for many years relied upon five rotary lobe pumps for transferring the mix of cocoa and condensed milk which makes up the crumb from process tanks to driers. The problem was that the pumps were constantly breaking down due to excess back pressure on the mechanical seals, and being obsolete the repairs and maintenance were becoming costly and irritating. Typically, pulling out the pumps and refurbishing them was taking around 14 hours, and spares had to be kept in reserve.
Chocolate crumb is a difficult product to pump as it is thick and highly viscous at its production temperature of 40⁰C and it becomes even more challenging when it cools as it tends to solidify. This in turns puts great back pressure on the pumps. Should there be any pump break downs remedial action has to be taken to avoid the crumb solidifying. Given the experience with Waukesha Universal 1 series pumps in other parts of the plant, AxFlow were asked for advice. After examining the application and nature of the pumped medium, a decision was taken to remove the old pumps and replace them with Waukesha 130U1's fitted with double O-ring greased packed seals.
"Our decision was to supply the pumps with motors, gear boxes and mountings suitable for hygienic applications," says AxFlow's Brendan Orange. "Meadow Foods have told us that the motors are saving energy and that the reliability of the pumps is excellent and none have needed to be touched since their installation some 18 months ago. In fact maintenance has been reduced substantially and now is largely confined to checking oil levels.