Peristaltic pumps from Watson-Marlow Bredel have been put to good use by Rowe's the Bakers who selected the technology to transfer egg white in glazing processes.
The pasty production line at Rowe’s has egg white being pumped into a glazing unit consisting of a container with two integral spinners.
The spinners create a mist that is allowed to fall and form a glaze on pasties passing below on a conveyor.
Rowe’s was using a conventional impeller pump for the task but faced repeated failures and downtime.
According to Phil Thomson of Rowe's, the impeller pump lacked a non-return valve, requiring the pump to be re-primed whenever the process stopped.
Moreover, he adds, since egg congeals, dedicated cleaning of both the pump and its connections is required increasing the downtime.
Thomson was aware of the capabilities of peristaltic technology since Rowe's already had chemical-dosing pumps from Watson-Marlow on site.
Watson-Marlow recommended a 520-series process pump after understanding Rowe’s specific requirements and also supplied a pump on loan for trial purposes.
A key advantage in peristaltic pumps is that the risk of the pump contaminating the fluid, or the fluid contaminating the pump is eliminated since the pumps have no valves, seals or glands, and the fluid only contacts the bore of the hose or tube.
Importantly for Rowe's, Watson-Marlow peristaltic pumps enable users to clean in-line at full velocity, without the intrusion of the bypass required by most other positive-displacement pumps.
The peristaltic pumps have a self-draining capacity, low-shear action and straight-through flow, and the tube is fully swept for superior hygienic performance.
After a two-week trial at the company's production facility in Falmouth, Rowe's acquired the Watson-Marlow 520 series pump.
Thomson comments that while impeller pumps are cheaper, they could easily burn out four units in a year on a single production line.
Once the downtime and labour costs are added, peristaltic technology makes far more economic sense, says Thomson.
Another benefit in peristaltic technology is that the pump has also reduced the amount of foam previously caused by air entrapment in the impeller pump.
Rowe’s hopes to achieve payback on their investment within 12 months and have in the meantime, ordered a second pump for another glazing unit.