A flow profile

The food and drink industry doesn't buy pumps. It buys answers to process problems. Why do you need to know how to specify a progressing cavity pump, a multi-lobed centrifugal pump, or a piston pump, when your process equipment supplier will install the right pump for the job?

The answer is because pump technology is changing and not knowing what pumps do could mean you chucking money down the drain, literally. Many processors still manually handle animal food waste, throwing fish-heads and chicken pieces into tote bins to be taken away by fork lift drivers to a skip for disposal. A progressing cavity pump, on the other hand, will not only pump whole chicken carcasses away from the production line but, when fitted with a grinder, will reduce the bulk of the waste going for disposal by as much as 70%.

A centrifugal pump specified in the time-honoured way according to frame size could actually be working at less than 20% of its peak efficiency in a process. Over a lifetime of 20 years, that could mean tens of thousands of tonnes of carbon dioxide chucked into the atmosphere and a total electricity bill 10 times the original capital cost of the pump. The answer is a centrifugal pump in which the impeller is designed and manufactured as a one-off, specifically to match your needs. One pump company believes it has found the way to do this without it costing a fortune.

Progressing cavity pumps use a helix rotor to create a continuous cavity that carries the pumped product intact through the pump. They are ideal for viscous and shear-sensitive products such as yogurt, cream, sauces and pastes, or products containing solid lumps such as strawberries.

When Mono Novo pumps launched a range of progressing cavity pumps it surveyed the food and drink industry to gauge where it should be pitching its new products. "Basically, it was to find out what people at various levels in food processing and manufacturing knew about pumps," says Mark Viner, UK sales manager. And the answer was 'not much'.

Less than half were aware of progressing cavity pumps and the information Mono got back has changed how it sells pumps. "It became apparent that what we couldn't do was simply sell a progressing cavity pump. That was not hitting the mark. People aren't buying pumps, they are buying solutions. They are buying answers to process issues. Customers are not really hearing you when you say: 'Would you like to buy a pump?'"

The answer for Mono was to produce a series of case studies based on previous installations. Take cider maker Bulmers. It had been having a problem emptying tankers carrying viscous apple juice concentrate. The previous pump would take four hours and then not completely empty it. So Mono installed one of its Helios pumps, which now unloads tankers completely in less than two hours.

"But what Bulmers didn't do was buy our Helios pump. They bought a solution to a problem," says Viner. "We now promote that case study to similar businesses so that we're not actually selling them pumps; we are selling a vat-emptying piece of equipment." The problem, says Viner, is that customers, potential or existing, buy turn-key process equipment to do a job. "There may be pumps in it, but they are not very apparent to the customer," he says.

"Our biggest competitor is often a wheelbarrow or a bucket. We put a pump in a bun-making factory. The place had got busier and the dough vats had got bigger until the two operators couldn't lift the vat up to empty it into the hopper of the machine that produced the buns. So we put in a pipe and pumped the dough." It has totally changed the process, says Viner, doing away with wheeling vats of dough between the dough maker and the bun-making line.

One reason for the food industry's lack of knowledge about pumps, suggests Viner, is that many companies have outsourced their engineering skills and rely on third parties to provide their engineering back-up. "The supposed benefit is a reduced price to the customer. But it detaches us from the end-customer and the net result is a disadvantage to the end-customer because we don't get the opportunity to offer process improvements."

Seepex pumps also manufactures progressing cavity pumps. Lesley Eaton, business development manager, food and beverage, agrees with Viner that a pump is not just a pump, but the answer to a problem. But you might not know that because you don't know what a pump can do, she says.

There are three ways firms choose a pump, she suggests. They look at what they did last time and if it worked they'll do that again. Or they will see what they have in the stores and try that. Or they will look for something else, and that can depend on who they spoke to.

But the only people who really have all knowledge are the people who make the pumps, she says. Her advice is: talk to the pump firm. Don't assume you can't do it. And if you have got a tote bin, think about installing a progressing cavity pump instead.

Chris Newberry is md of Pump Engineering. He too is concerned at the food industry's lack of appreciation of what pumps can do.

For example, Pump Engineering supplies a range of piston pumps for very high viscosity products such as peanut butter and tomato purée. But these pumps can also provide a solution to cutting the costs of cold storage.

Newberry explains: "If food is kept in a cold store and the company has to warm it before it can handle it, then there are huge energy costs involved. But if you have a pump that can handle high viscosity products in their cold state, then that saves processing costs and warm-up time."

Buying a pump may well mean buying a solution to a problem. However, sometimes that solution is not necessarily the most efficient. The performance of centrifugal pumps, for example, used widely in the brewing and drinks industries, is dictated by frame size in effect the dimensions of the electric motor that drives the pump. And since motors are manufactured according to a standard range of frame sizes, you have to select a size closest to the duty you want.

This means that a pump chosen according to the nearest suitable frame size could actually be working at less than 20% of its peak efficiency. It is estimated that about 50% of centrifugal pumps operate between 10% and 40% of their maximum efficiency.

To solve this problem, centrifugal pump manufacturer Amarinth has been granted £160,000 by the Carbon Trust to develop high efficiency pumps using a new process for the design and manufacture of impellers. The idea is that instead of choosing a pump from a range of frame sizes the heart of the pump, its impeller, will be designed to meet a customer's pumping duty requirements and so will operate at maximum efficiency. The first of these bespoke pumps should be available in a year's time.

The project aims to reduce impeller design lead-time by 25% and to slash the costs of making the foundry pattern needed to cast it. Amarinth is hoping to get this down to a tenth of current pattern-making costs. It is also aiming to cut total lead time from order to delivery to less than a week. The resulting impellers will reduce energy consumption by between 10% and 25% and it is estimated that the project could reduce annual carbon dioxide emissions in Amaranth's target market by 17,000t by 2020 and by 110,000t by 2050.

But producing one-off bespoke impellers is not generally commercially viable and so Amarinth will be use the latest computer-aided design techniques, combined with 'rapid prototyping', to cut the costs of making foundry patterns and to reduce lead times.

Steve Buckley, sales and marketing manager, says: "We felt there was a market where, rather than selecting a pump from a range of frame sizes, we would actually design a pump specifically for the duty needed. If you select your pump duty from a series of pump frames, it is only by good luck if you actually get a pump that will be working close to its best efficiency. Depending on the pump design, that might already be as low as 50%. And in some cases, pumps might be selected with efficiencies of less than 20%."

This tends to be true for smaller pump sizes, typically the sort of pump you would find in a food factory or brewery, says Buckley. And the capital cost of a pump is probably less than 8% of the actual electricity cost operating over a 20-year period. And that's for an efficient one, he says. "What we are expecting is to be able to improve performance by 1015%." FM