Labour shortages and competition pressures in the food sector will prompt a greater reliance on technological efficiency to drive productivity. Pumps can play a key role, reports Brian Attwood.
It’s the UK’s largest manufacturing industry, yet food and drink may also be the sector most under pressure during the next decade.
With much of its market in Europe now under threat of contraction after this country withdraws from the EU and a sizeable minority of its workforce, the battle is on to ensure productivity and process efficiency can ensure competiveness is maintained and built upon.
Technology is getting smarter and that includes pump technology. Yet, where the latter is concerned, the factors to account for in the food environment are common to most other sectors and include: temperature, pressure, volume, flow, abrasiveness and flow character.
But there are other considerations that become magnified in this sphere. The presence of solids and their handling, the need for accurate dosing of ingredients, plus, of course, hygiene.
Which pumps one opts for depends to some degree on the stage of the production process and the task. For Seepex business development and marketing manager Lesley Eaton [pictured left], though, progressive cavity pumps are well suited to tackling a myriad food processing roles.
“There remain challenges associated with pumping foodstuffs; not least the ability to handle solids as well as liquids, and maintenance of product integrity,” she says.
Eaton cites 10 examples that illustrate the usefulness of PC pumps in particular:
Maintaining product integrity PC pumps move product through a series of cavities, preventing slip from the discharge back through the pump which would in turn create shear. As there is no squashing action either, soft solids can be handled with little or no damage.
Lifting products High suction lifts of up to nine metres can be achieved, making PC pumps ideal for lifting products from IBC, barrels or mixing tanks. The ability to pump against almost a full vacuum enables the efficient use of degassing equipment and enhances the quality of the final product.
Batch and continuous dosing The cavities have a given chamber volume which enables batch dosing applications where specific amounts of product are needed. Low pulsation enables smooth, continuous action, with accurate addition of ingredients or chemicals into a liquid flow possible without the need for complex controls or calibration.
Solids While PC pumps maintain solids integrity and process efficiency, says Eaton: “the development of sophisticated auger mechanisms in some PC pumps means that they have the ability to handle and even mix solids – liquid can be added to solids in the feed auger, or solids can be added to a paste, with the action of the auger mixing the two before feeding them into the pump.”
Variable flow rates PC pumps manage flow rates from 100ml/hr to 500m³/hr and handle temperatures ranging from 20°C to 220°C. “As the flow volume is constant for each cycle of operation, and is proportional to the rotational speed, calibration is simple and unaffected by the viscosity.” Pump speed alone needs to be altered to vary the flow volume.
There remain challenges associated with pumping foodstuffs; not least the ability to handle solids as well as liquids, and maintenance of product integrity
Lesley Eaton, business development and marketing manager, Seepex
Viscosity Development of auger mechanisms – fabricated as part of the integral coupling rod between the drive and rotor, using the rotation produced by the drive – to constantly feed viscous media into the pumping elements has supplemented PC pumps’ suction qualities. Media with dry solids content up to 45% and viscosity in excess of 1,000,000 cps can be successfully transferred.
Hygiene Ingredient dosing, product transfer, accurate metering of product directly into production processes, and filling of finished products can be achieved using PC pumps with cleaning-in-place (CIP) as standard, which comply with the strict hygiene standards demanded by today’s food processors.
Operating pressures Transferring products via pipework and coping with valve configuration, downstream equipment –such as heat exchangers – creates operating pressure challenges. PC pumps are able to generate pressures up to 48 bar as standard, due to the interference fit between the rotor and stator and the absence of slip between the pumping elements.
Installation and operation PC pumps boast forward and backward pumping action in the same pump, so one pump may do the job of two alternative designs. As check valves, pulsation dampeners and calibration pots are not needed, system costs are reduced.
Waste disposal By-products and solid and liquid waste from food and beverage production can be removed in hygienic, enclosed systems using PC pumps, while Seepex’s patented design of rotating knives on the auger coupling rod, with static knives on the pump body, provides a refinement.
While acknowledging the effectiveness of PC pumps for low velocity and shear, AxFlow emphasises the niche applications of a variety of other types.
Rotary pumps – both lobe and piston – perform well with thick mixes while preventing unwanted separation and all-important pulse-free pumping.
For more delicate tasks where precise timing and volume counts, reciprocating positive displacement pumps offer effective in-line proportioning and dosing of liquids, says the company: “The factors affecting the choice of a metering or dosing pump as opposed to other types of pump are normally associated with precision over a range of flows and the fact that the capacity is not influenced by pressure fluctuations within the process.”
Meanwhile sensitive solids and flavour dosing that needs to be added to a process and ensure accuracy and repetition favours the use of peristaltic hose pumps. Squeezing the hose between rollers at specific intervals creates a positive displacement action, ensuring no opportunity for contamination.
Also providing positive displacement, air-operated double diaphragm pumps boast an absence of close fitted or rotary parts which are vital for allowing solids to progress without damage or difficult products to be employed without disrupting the overall fluid.
As ever, the golden rule is to take a holistic view when purchasing or choosing. Cheap buys do not hold their value if the pump is not fit for purpose and consequently may cost more when maintenance and installation are factored in.
Short life cycle represents a bad investment and a poorlyfunctioning pump has the potential to create a food safety issue too.
Hopping glad
Breakthrough US technology gives traditional craft beer an edge…
A traditional craft brewer has turned to a revolutionary technique based on a recirculation pump with a chopping impeller to get more from its hops.
Black Sheep brewery, set up by Paul Theakston of the Theakston brewing dynasty, has made use of US-based Torqueflow- Sydex’s Hoptimiser brand’s Rolec DH – a dry-hopping system newly launched in the UK.
“Preferences were changing, with growing demand for hop-forward ales and craft beers,” says head brewer Phil Douglas.
“Malted barley and hops are traditionally raw materials added to beer to balance sweetness and bitterness. Beer that is more balanced toward the hop side is considered hop-forward.
“As a result, many brews now require more and more hops to enhance this characteristic.
“The big advantage of the Rolec DH is that it breaks up the hops, thus introducing greater hop character to the beer,” says Douglas.
“Also, thanks to increased surface area and greater contact with the entire beer volume, we can use less hops to achieve the same hop character. The manufacturer says we can use as little as 40% of a traditional dry hop load. While we are not at that level yet, we are certainly using less hops, which of course has a financial benefit. As a result, I estimate we are on course for ROI within 24 months.”
While we are not at that level yet, we are certainly using less hops, which of course has a financial benefit
Phil Douglas, head brewer, Black Sheep brewery
The US-manufactured Rolec DH allows dry hopping to be performed in a pressurised, closed environment that is purged of air using CO². The integral SBI pump features blending teeth to increase the surface area of the hops. The unit will chop a typical hop pellet up to four times before it is induced (using differential pressure created by the shear pump) into the beer stream with no adverse effect on suspended yeast, head retention or any other aspect of the beer.
The pellets are reduced to the right size so they can settle during the dry hop holding period.
Simultaneous to hop induction, the Rolec DH recirculates the fermenter, says Douglas. “Since we were effectively already doing this using a rousing system, we were able to use our existing pipework, meaning our new dry hopper fitted easily into place.”
David Lee, UK managing director at Torqueflow- Sydex, says the 4 kW motor-driven system offers a pellet capacity of 20 kg and a recirculation rate of 3.4 hectolitres per minute.
The portable unit comes equipped with pump, VFD, input cord and CO² regulator. All components are sanitary with no additional CIP pump required.
