Energy efficiency

Exploring the “steam-free” concept

1 July 2012



Is the steam-free/reduced steam laundry the way to ensure sustainability? Janet Taylor investigates


Managing natural resources to ensure a sustainable future has become a top priority for the laundry industry. This has led to an increased focus on systems to optimise energy. Reducing or eliminating the use of steam as a primary heat source for the laundry line, moving away from the central boiler house, has been seen as one route.

At Christeyns, Philip Poeth says that in 2003 the company, working with an engineering partner, produced a steam-free concept for washer-extractors and in 2008 the partnership extended the concept with a system for tunnel washers. ?

The Zero Steam system is based on the principle of "indirect heating". There is no direct contact between the main wash water and the generator flame to avoid a build-up of sediments in the hot water generator. A heat-exchanger is used to transfer heat from the hot water produced by the generator. The water, which can be up to 94C, flows inside the exchanger’s rotating discs in a pressurised circuit.

The main wash water is pumped from the tunnel to the heat-exchanger and flows around the discs. For optimal exchange the system creates turbulence in the liquids and the heating water and the wash water operate in a counterflow. The heated wash water then flows back to the tunnel washer under gravity.

To date the company has around 20 installations in?Europe. Poeth says that most interest comes from new-build laundries or those that are expanding.

He believes that interest in steam-free or reduced steam washing will grow. In addition gas heating is increasingly being used on ironers and dryers because this method widens the laundry’s options.

An advantage of steam-free washing is that it offers more opportunities to introduce other energy saving concepts. For example, Christeyns has combined the Zero Steam concept with solar energy systems in two installations.

Indeed the need to see steam-free systems as part of a whole energy saving strategy is a common theme.

Ecolab has developed the modular PERformance system, which allows laundries to become more resource efficient in stages. PERformance Ultimate eliminates steam completely and Michael Brueggemann says it has several advantages. It saves all the costs involved in installing and maintaining a boiler and in distributing the steam. With Ecolab’s Aquaheater at its heart the system can achieve up to 99.7% energy efficiency and savings of 10 – 30%

But, says Brueggemann, an Ultimate installation goes beyond replacing a central boiler system with individual gas-operated Aquaheaters. Benefits can be expanded with Ecolab’s PERformance 40, which allows efficient washing at low temperatures.

To achieve optimum savings the Aquaheater must be integrated with water and energy recovery systems that capture waste energy from one process and re-use it in another. In this set-up the Aquaheater will heat-up water for the wash at the beginning of the day. Once operations have reached the target temperature, individual heaters can be switched off and the machines run from waste energy.

Jensen’s CleanTech concept also stresses the importance of integrating different energy-saving approaches.

CleanTech offers various options for eliminating the boiler house including direct, self-contained gas-heated equipment and self-contained high-speed or low-pressure steam generators. The company says it has sold close to 40 installations where the laundry operates without a boiler house and it believes that the boiler house, steam boilers and steam piping “definitely belong to the past”.

Jensen says the way forward is through self-contained energy sources that only call-off energy when needed. ?This approach can be used with single machines but ideally it should be applied to all key machines. When this approach is applied throughout the laundry, Jensen claims it can achieve energy savings of up to 60% per year with the additional benefit of 25% increase in productivity.

Andreas Langer at Kannegiesser takes a slightly different approach. The emphasis here is on the management of resources. This is based on three factors: Optimised machine technology; comprehensive water and energy management systems and lastly a suitable heating system.

It is essential to have efficient processes, says Langer. The first focus should always be on achieving a target consumption in terms of kWh/kg. Once the processes are optimised and energy use reduced, then the laundry can consider the heating source.

Applying energy saving and heat recovery systems to reduce primary energy demand allows laundries to operate without a central steam boiler.

Kannegiesser can meet this with gas heated PowerTrans batch washers as well as gas-heated dryers, finishers and ironers. However, the company also believes in individual solutions which can include traditional steam laundries where processes and systems have been optimised to minimise consumption; laundries that still use a central steam boiler but also have gas-heated machines (mainly ironers, finishers and dryers); and laundries with gas-heating in the finishing area and decentralised high-speed steam generators for the washing machines.

Stressing that there is no single answer, Langer says that Kannegiesser equipped one laundry that runs with low-pressure waste steam from a neighbouring paper industry.

He adds that the decision lies between a central or decentralised system rather than between steam or gas heating and it is necessary to look at the benefits over at least 10 years.

Girbau’s product manager Jordi Martinez says that the company has developed self-contained thermal-oil ironers, high-efficiency gas-heated dryers and gas-heated ironers. It also provides full recovery systems – water- to-water, air-to-water, or air-to-air.

He says that steam-free operations are easier to achieve with new build laundries but the company can convert part of the laundry to steam-free operation, then change over gradually.

Asked about the future he says that the customer wants to operate with low energy consumption and low maintenance requirements.

Steam-free operation provides both.




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