Dairy Innovation

Eccentric pumps offer ice cream solution

dairy tech 6 2016
Belgian ice cream maker Ysco has switched to seal-less Mouvex SLS Series Eccentric Disc Pumps for pumping ice cream from its preparation vessels through 220m of piping to its ice cream freezers.

Supplied by The Netherlands-based pump distributor, Spin Pompen, the Mouvex pumps overcome the challenges of the traditional centrifugal pumps that Ysco previously used.

“Ten to 15 years ago, the majority of ice cream mixes were low viscosity,” said Spin Pompen manager Bellux Peter Van de Sompel. “Over the years, what we’ve noticed is that the flowability of ice cream mixes has changed. There are more ice cream variants and more inclusions such as nuts, flavours, chunks of fruit or candy or other ingredients added for taste etc, which make today’s ice cream mixes more viscous.”

While in the past a centrifugal pump was ideal for pumping ice cream with continuous pressure that fluctuates only within a very narrow range, the changing make-up of modern ice creams and their increased viscosity made the centrifugal pumps’ task far more complicated.

“With higher viscosity you need a volumetric pump with a very stable flow that can be regulated in a very linear way. You need a pump with an equal flow, plus a 1:1 ratio of flow to speed,” said Peter, who explained that if during the transfer to the freezer the flow pulsates, the time the ice cream mix spends along the wall of the pipe is not under control, and this impairs the quality of the end product.

“The classic centrifugal pump solution does not work properly with mixes in excess of 500cP — and often as high as 2,500cP,” said Ysco engineering assistant Krist Levrouw. “Under these circumstances, centrifugal pumps are unable to generate the pressure required to transfer the mix and feed the freezer properly. As a result, you can’t empty the vessels completely and you have too much waste.”

Now, the installation of the Mouvex SLS Series Eccentric Disc Pumps, with their low shear rate, very low pulsation, low slip, self-priming and dry-run capabilities, allows for smooth and effective transfer of Ysco’s ice cream products. Not only this, the pumps show very limited variation in flow rate under the varying conditions of pressure and viscosity; and they allow a high degree of product recovery thanks to the strong vacuum and compression effect generated by the tight contact between the disc and the cylinder.