The right pump for waste cooking oil
Supplying an ATEX-approved pump for a high-pressure, high-temperature application can be quite an ask. Yet, in many ways, for an oil refinery in the South West of England, their need was a typically specific one for the industry, especially as the challenge was to process waste cooking oil, as Borger UK’s Managing Director, David Brown, explains.
The global need to effectively utilise waste cooking oil (WCO) in petrochemical and high-quality gasoline production has never been so great, but finding a long-lasting pump that could cope with high pressures and handle fluids with high viscosity was proving difficult for this particular refinery. That was until they consulted the local tank-cleaning company, who are regular visitors to the site. For their tankers, the industrial cleaning firm had been using pumps made by Borger for many years – and with no reported problems, had no hesitation in recommending them.
Robust solution
With its proven range of ONIXline pumps that benefit from a large-volume sealing area, Borger UK’s Managing Director, David Brown, was confident that his company could provide a robust solution for the demanding application.
“We enjoy a challenge,” said David, “but at 14.5 bar, a temperature of 70°C and more than 50% solid content with a Viscosity of 14 centipoise, we knew we had to create something special. There’s also getting the balance right between high internal fluid temperatures and ATEX surface temperature limits on the outside.”
Initially, the refinery wanted to take the customised pump on a rental basis, but Borger worked closely with its customer to provide a purchase option that (subject to a successful trial) would offer much better value for money.
David added: “Finding that sweet spot between a pump that can handle high temperatures but also handle highly viscous products has taken a distinct turn for the better in the world of pump evolution.
“Seal-less magnetic (Mag) drive pumps are suitable for high temperatures and prevent any leakage of fluid, which is clearly important when dealing with chemicals and corrosive liquids. They have a pretty simple design and are generally quite reliable. However, this isn’t the case at all when trying to deal with viscous fluids. Magnetic drive pumps are also far more expensive than mechanical seal pumps. Whilst Magnetic pumps can do a great job in certain applications, I don’t buy the argument that they’re somehow automatically better on maintenance because as soon as a slightly difficult, non-clean liquid comes along, the user is entering a whole world of pain, with an excessive need for maintenance and repairs”.
David continued: “You also won’t have to look too far to find a manufacturer of twin screw pumps, often described as ‘durable and low on maintenance’. This is true for durability and for handling highly viscous products, but it is a totally different story if it is a liquid that contains some solid particles. Less of a story and more of a nightmare, with arduous and very expensive maintenance bills on top of a hefty purchase price.”
With the Borger pump having more than proved itself during a lengthy trial at the refinery, the intake of waste cooking oil was increased almost six-fold, requiring a much larger custom-built Borger ONIXline pump (30 kW) with specially machined stainless-steel rotors to operate 24/7 at 40m³/h (compared to 7m³/h for the first unit).
David added: “The new pump at the refinery has proved just as popular as the first because it gets on with the job and is easy to manage. As the need continues to address the pollution caused by waste cooking oil and, more importantly, treat it for reuse, refineries can see that there are now the right type of pumps available to process it efficiently and effectively, with just a small footprint. Refineries can choose leaner, more cost-effective pumps with superior rotors that promote maximum energy efficiency through gentle, almost pulsation-free pumping – with the added benefit of no wearing parts. There’s also maintenance-in-place (MIP) designed in, so routine servicing is much, much easier, with simple tools and very little downtime compared to other pumps. The installation at this refinery in the South West proves at last that the happy medium for high temperatures and highly viscous products is now possible – with much lower capital and ongoing maintenance costs.”
