Greencore adds peristaltic technology at Yorkshire site

Selby, UK – Food manufacturer Greencore Group Plc] has reduced downtime and repair costs on the water treatment plant at its Greencore Grocery site in Selby, North Yorkshire, following the installation of a high-pressure peristaltic hose pump.

Greencore Grocery manufactures a wide range of both branded and customer own-brand sauces, pickles, and soft drinks. The cleaning and change over process between different products, produces a small quantity of liquid waste (food effluent). This can lead to significant fluctuations in pH levels, from 4 up to 12 in some instances.

Until recently, pH levels at Selby were corrected using 32% caustic soda (sodium hydroxide – NaOH) through the facility’s water treatment plant, which is owned and operated by United Utilities, the UK’s largest listed water company. With Greencore responsible for consumable costs, a cost-down exercise was commenced to seek an alternative to NaOH.

“The Greencore Grocery facility at Selby is a high volume plant where there can be between 10 and 26 ‘washouts’ a day depending on order schedules,” says Peter Wadsworth, Craft Technician at United Utilities.

“In order to find a more cost effective method of correcting the pH in the processing machinery, we trialled a product called ‘Mag Mex 1060’, which is a magnesium hydroxide solution [Mg(OH)₂], to  Correct the pH levels.

Carrier water is used to dose the Mag Mex into the system at Greencore Grocery, but to do this effectively a suitable pump is required.

“We started off using fairly ‘cheap and cheerful’ dosing pumps, but this proved to be inefficient as we spent two days a week repairing them,” said Wadsworth. “Because magnesium hydroxide has low solubility in water it makes for a pretty abrasive fluid. We found the grit would attack the mechanical seals and drain plugs on the dosing pumps, thus requiring repair.”

One of United Utilities sister sites was using a peristaltic pump from Watson-Marlow, and this was subsequently recommended to the process engineering team at Selby. As a result, a Bredel SPX50 high pressure peristaltic hose pump (50mm diameter) was installed in September 2009, and ever since there have been no abrasion issues causing downtime or repair.

With peristaltic pump technology, nothing but the hose or tube touches the fluid, hence there is no chance of the abrasive fluid damaging pump components. The peristaltic design means there are no valves, seals or glands to repair or replace. Replacing a hose or tube takes only minutes and they are relatively low-cost items compared to spares for other pump types.

At Greencore’s Selby site, these features helped to lower maintenance, low cost solution, which is just as well for an operation that produces around 250 million jars per annum across circa 500 different product lines.

“Any downtime in an operation of this magnitude can be very costly,” said Wadsworth. “I’m sure the SPX50 paid for itself extremely quickly. In fact we are going to trial an identical pump on site for sludge transfer between tanks.

Over 600 people are employed at the 23-acre Selby plant, which has received considerable investment over the past 10 years. The site is said to house some of the most modern, hygienic and efficient production facilities in the UK and carries AIB accreditation, being placed in the ’superior’ category, achieving BRC Grade A.

.