Achieving Efficient Baking

Conscious of the need to cut energy costs and reducing carbon footprint, more bakers are seeking advantages of efficiency-saving systems and ovens. David Abbott reports.

Equipment manufacturers are keen to help bakers get the very best from their ovens, which will become ncreasingly important to bakers in the coming year with the current economic conditions squeezing budgets and the cost of raw materials rising.

Therefore it makes sense to start finding ways of maximising energy use. Last month MIWE (Michael Wenz GmbH) launched a new oven energy reduction system. Although existing ovens are fairly efficient, MIWE points out that a lot of energy is still lost through the chimney.

The new MIWE system tackles oven flue gas and steam separately, directing them through separate heat exchangers, then discharging through a single chimney. This cunning piece of engineering allows the energy contained in the steam, which is greater than that in the flue gas, to be utilised, resulting in considerable savings.

In the new MIWE eco:nova system, the flue gas is fed through a neutralisation unit which extracts poisonous
sulphur dioxide.

This itself is a major environmental benefit, and is something that green-conscious bakeries, through marketing materials and advertising campaigns may want to promote.

The correct draught in the MIWE eco:nova is provided by an electronically frequency-regulated fan that creates the necessary consistent vacuum in the exhaust system and a new patent-applied for draught adaptation on the oven, which can be individually set for each oven accurately to 0.01 mbar.

MIWE’s proud claim is that consistent baking results are now possible; completely independently from climatic influences and factors such as flue diameters and the amount of piping.

The MIWE eco:nova has been designed for use with many types of baking ovens and different burner capacities, but is best suited for bakers with more than four ovens and a gross burner capacity of at least 320 kW. There are almost no upwards boundaries and the eco:nova can be constructed in modular steps of 160 kW (burner capacity), providing considerable flexibility.

But can the benefits be quantified?

Yes, they can claim MIWE, who says the new system will allow around 25 per cent of the energy used in baking to be recovered in the form of hot water. The benefits are obvious but there is also scope for utilising this for washing units, and the heating and hot water supply needed in bakeries: and that’s a benefit which firms will be able to quantify pretty easily.

However in most cases the typical savings in a single day can be about 600 kilowatt hours. This depends on how much energy is consumed during baking and the savings will also vary from product to product.

For example, the savings from crusty rolls are far greater than those for croissants. But based on the results of trials which MIWE has carried out in German bakeries, the payback on the required investment is reckoned to be just a few years dependent on energy costs.

In the UK and Ireland the system is going to be supplied by European Process Plant (EPP). EPP director Stewart Morris is confident that the system will be a canny investment for all bakeries.

“Energy costs continue to soar and MIWE have responded to this by designing a highly effective heat recovery system specifically designed to operate at its optimum in the conditions found in bakeries.”
MIWE are well known in the bakery engineering community, but they are not the only player in the market and another name to conjure with is France-based Mecatherm.

Mecatherm produce an excellent range of ovens and they too are in the efficiency game. It’s essential for any oven and the precision with which heat can be applied is also a plus as far as energy efficiency goes with the FTM.

But the latest Mecatherm three-deck tunnel oven FTM has reduced steam consumption and uses indirect heating through gas or fuel burners for low energy consumption.

Capway Systems contribution to efficiency gain is the development of flexible lines which enable a fast changeover and increased loads so that the same amount of energy can be used to bake more bread.
These are all big players of course, but it does sometimes pay dividends to look at some of the slightly smaller companies who are perhaps less well known, but match the quality of the main players. In fact, competitive pressures can even mean that they are good places to find a good deal.

UK-based Spooner Industries are specialists in heat transfer and forced convection. They make equipment for several industries which allows for some fruitful cross-overs of knowledge and experience, but bakery is a mainstay of their business.

The company has been in existence for around 75 years and today, with a staff of 100, makes mainly conveyor tunnel ovens, steel flat conveyorised ovens, stone bake ovens, solid band biscuit ovens and they also do a cereal oven. Spooner ovens are mainly gas heated.

“With energy costs rising we’re looking to making them as efficient as possible”, says sales and marketing director Steve Newell, who points out that Spooner, given their specialist skills, put a lot of effort into heat recovery.

Spooner ensure that their ovens take the exhaust heat and re-use it again, reducing the amount of hot air which is simply expelled through the chimney.

Ovens are a bit of a black art, or at least, they used to be. Newell says that Spooner produce ovens which use both convective and radiant heat, enabling a range of different products to be baked, but control is one of the key qualities required for any oven and it’s also a vital area for efficiency gain.
To this end, Spooner fit inverters onto the motors for the oven fans, giving much better control and thus saving energy.

The other key part of control though is the PLC, and here Spooner has developed various energy saving modes.

In fact, Newell is a bit wary of revealing all the details about the PLC, so if you want to find out just how good they are, you’ll have to make a commercial enquiry.

But Spooner are clearly proud of what they are doing and as Newell points out, they are setting about developing their products by linking up their own knowledge base to that of several leading universities in the UK.

Newell believes a good oven must provide an even bake across the width and Newell adds that Spooner make a very wide oven, which does exactly that. Also bakers will be looking for low running costs, very high levels of reliability and high levels of throughput. These are all qualities which Spooner is keen to ensure are part and parcel of its ovens.

And even with impressive returns on investment, new plant equipment is an expensive outlay these days, so a lot of bakeries might very well be interested in exploring how their existing equipment can be improved. So it’s interesting to learn that Spooner also re-fit ovens, with the particular aim of increasing efficiency.

Newell explains that the company’s expertise in heat transfer makes them ideally equipped to carry out energy audits and re-fit bakeries existing ovens to improve the performance.

That involves improving controls and heat exchange, which Newell says is ‘right up our street’.
And in the current climate, you’d have thought that this would be an area of business which could expand considerably over the next few years.

Currently Newell says business is booming and despite negative media reports, Spooner are finding the market very buoyant: “Like the rest of the world we’re waiting to find out what impact the current financial crisis is going to have, but at the minute we have a very strong order book – probably at record levels – and we’re hopeful it’s going to carry on like that.”

Spooner is a specialist after all says Newell and that means that they have the knowledge and experience to devise exclusive and specific solutions for the companies they work with.

“We don’t particularly have a standard product,” says Spooners Newell.

And a fundamental part for Spooner is forming partnerships with customers. “We want to work with customers and make sure it’s perfect for them,” says the sales and marketing manager.

If bakers are seeking efficiency gains, now seems to be a good time for bakeries to be looking for a good deal.