A new look at piston pumps for food processes

A good pump needs to meet the requirements of the product, as well as normal food handling hygiene requirements, such as clean-inplace (CIP).

Not all are capable of maintaining product quality at a reasonable cost, plus ensuring the required pressure in the system. These challenges inspired the production of the BP Series of piston pumps from HRS Heat Exchangers.

The HRS BP Series is a purpose designed reciprocating positive displacement pump, with an expanding cavity on the suction side and a decreasing cavity on the discharge side. Material flows into the pump as the cavity on the suction side expands and is forced out of the discharge side as the cavity collapses.

This series features a hygienic design that incorporates a separator fitted between the piston and the hydraulic chamber to ensure that there is no contact between the product chamber and the hydraulic oil. Once the pump is in operation, no part that comes into contact with oil comes into contact with the product.

The standard BP Series has an adjustable flow rate between a minimum of 200 litres/hour and a maximum of 12,000 litres/hour, and features a high-pressure drop of up to 30bar. It is suitable for a wide range of high viscosity, shear sensitive and large particle-containing fluids. Clap valves allow pumping of whole fruits or vegetables, and an alternative piston pump with a pneumatic cylinder can be supplied for low-pressure applications of less than five bar.

Multiple lines, one pump

Following the success of the standard BP Series in a range of applications, HRS Heat Exchangers have developed two variants. The first was the BPM Series, a mobile version of the standard BP Series pump. This is mounted on a mobile skid unit for easy movement, allowing it to be used across multiple production lines and locations, something that is increasingly popular with food manufacturers producing short runs of specialist products.

For companies, there is the benefit of a series pump across multiple production lines without the need to invest in a dedicated pump for each line

For companies, there is the benefit of a series pump across multiple production lines without the need to invest in a dedicated pump for each line, resulting in considerable capital savings. When dealing with highly viscous materials, particularly at low temperatures such as hummus at 5°C, the product’s thickness can make it hard to prime the pump when starting production following cleaning.

The new BPH Series is designed to overcome this. It uses a gravity-fed hopper, together with a screw conveyor, to initially push product into the body of the pump. Once the cavity on the suction side has been filled, the pump is primed and will then operate as normal with a constant stream of product.

Matt Hale is international sales manager, HRS Heat Exchangers