Efficiency to the fore

The need to make more efficient use of energy and water has been influencing the tunnel washer market for several years, but can be expected to gain even more momentum over the next year.

Central laundries are becoming more and more cost conscious and this has implications for the choice of tunnel washer, says Kannegiesser. While saving water has been important for laundry customers in several countries, the company believes that over the last year customers investing in a tunnel washer line have put particular emphasis on energy savings.

Certainly at last year’s Texcare International in Frankfurt, LCNi noted that energy saving was a significant trend not only for the tunnel washer line but throughout the laundry.

Thus Jensen’s theme was its Clean Tech concept, which aimed to switch the various laundry equipment components from steam to direct gas heating. It claimed the concept would produce energy savings for the laundry of up to 60% and also lead to higher machine performance.

With regard to the tunnel washer, steam-free operation will be offered as an option on all the Universal, Universal SL and HighLine tunnels. The steam-free tunnel washers will be equipped with the gas operated Aquaheater. This heats the process water in the compartment, which previously needed steam injection. The system also includes an integrated modular tube-in-tube heat-exchanger to reduce energy use by around 30%.

Since Texcare the company has sold around 10 gas-heated tunnels for steam-free operations and it believes there is high interest in this market. In the longer term, it believes there will be even more demand for energy and water saving technologies, especially given rising energy prices and the present unstable economic situation in many countries.

Higher energy prices will also mean that there is a better return on investment.

The steam-free concept was also being promoted at Texcare by resource systems specialists Christeyns and Ecolab.

At the show Christeyns commented that while systems to reduce the use of steam had been available for some time, a system that allowed a tunnel washer to operate without steam was a real advance. The closed system uses fresh water that is heated by a gas burner and then goes into a heat-exchanger. Water is taken from the middle of the main wash to avoid soil deposits from dirty water.

Ecolab has developed a modular system for maximising both energy and water use. PerFormance Basis introduces energy and water saving washing. PerFormance Plus extends this system taking account of the whole process from boiler house to washing and finishing.

However, it is PerFormance Ultimate that takes the system into the steam-free area and will allow new laundries to be built without a boiler house. The company claims the steam-free option is up to 30% more efficient than that of the traditional laundry.

Kannegiesser’s Green Laundry display at Frankfurt centred on a series of energy-optimised machines including the PowerTrans Jet tunnel washer, which it describes as the most important development of recent years.

This was first introduced at its in-house show in 2007 as the Jet Centrifuge. It was based on the principle of taking the extraction unit into the body of the machine and rinsing linen in the extractor rather than in a separate compartment. This process involved extracting the main wash water before the load is rinsed, so that the load will absorb the fresh rinse water in a relatively short time. This means that less fresh water will be needed to dilute the water that remains in the linen after pre-extraction.

The Jet concept saves both energy and water and the machine has a more compact design as fewer compartments are needed.

At Texcare 2008 the company introduced a second Jet machine working on similar lines but with extraction carried out by a press.

Kannegiesser reports that the German Hohenstein Textile Institute has certified that both versions give excellent rinse results.

The company now says it has 25 installations for these machines.

The continued emphasis on cost savings is influencing the laundry sector structure as well as the machine design.

Girbau of Spain, which manufactures for a worldwide market, says it has noticed that more customers are now outsourcing their laundry service and that this opens up fresh opportunities for heavy-duty equipment manufacturers.

First, says Girbau, large customer groups are centralising their laundry services into a high-volume processing plant with tunnel washer and the appropriate finishing lines.

Second, it believes that small and medium industrial laundries are benefiting from a move to subcontracting and as a result are investing in tunnel washers to become more competitive.

It also notes that in all industrialised countries the move from washer-extractors to tunnel washers has quickened.

This has been due to a combination of fluctuating energy charges, lack of resources and high labour costs.

Where once the companies would consider a switch when volumes reached 6 – 8tons/day , Girbau says that now laundries will consider making the change when the workload reaches around 4tons/day.

These plants are relatively small and therefore need smaller machines of 7 – 10 modules but the main demand will still lie with larger industrial laundries requiring twelve or more compartments.

Pellerin Milnor, the New Orleans-based international manufacturer that has made tunnel washers one of its main lines, reports that currently it is seeing a lot of replacement sales. Laundries handling industrial applications and mat washing are looking for load sizes of 100 – 120kg. All customers are looking for low water and energy consumption.

The company’s novel concept of an “interrupted counterflow” opens up the possibility of unprecedented savings, while at the end of the tunnel line centrifugal extractors, 50 –115kg, loading and up to 1,000G and single stage presses, with the same capacity range and pressures up to 50bar, reduce moisture efficiently.

The company claims to have the “world’s largest tunnel washer” in the 92048, with a batch size of 250lb (115kg). This can handle any type of load from sheets and towels to heavily-soiled goods such as bar mops, floor mats, industrial uniforms, shop towels and kitchen linen. But Milnor is also now responding to demand from companies that have industrial workloads but limited floor space.

The 76028 CBW introduced at Texcare is a five-module machine that uses a counterflow system for powerful performance and introduces a standing bath washing system (patent pending) to reduce energy and water use. In each module, the process begins with a standing bath chemical injection.

The module achieves both the required water temperature and the chemistry needed for the linen type. As soon as the correct chemical balance is reached the machine’s counterflow system comes into action, diluting the load’s soiling.

Goods are then transferred to the next module but the soiled water is not transferred with the load, so there is no need for extra water to counteract the soiling and overall consumption is reduced.

The counterflow system is also designed to reduce wear and tear on the linen and prolong its life.

Productivity is always an important issue in any laundry. In Kannegiesser’s experience many laundries are organised around the 50kg batch.

When the tunnel line is completed by the company’s turbo extraction press, laundries can achieve a good production rate as this reaches full extraction pressure in 30seconds and the linen’s residual moisture after extraction is low. However, the company can also supply machines to handle 75kg or 100kg batches and these are preferred by larger laundries with high degrees of automation.

The company also reports that most of the tunnel washers that it sells are of the bottom transfer type. Kannegiesser can also meet the requirements of laundries that specialise in certain applications such as workwear or table linen.

These customers often choose the PowerTrans Rotaflex which has a rotating action that gives a higher degree of mechanical action while being gentle on the fabric.

Jensen sees three main trends in terms of customer requirements over the past couple of years.

The company believes there is still a trend to larger batch sizes, although it has also sold 25kg batch machines, mainly to cruise ship laundries, which have very limited space. It also believes that there is a greater emphasis now on hygiene.

In terms of technology therefore it picks out two recent developments as being particularly significant. The HighLine tunnel washer can be switched from a swivel action for lightly soiled loads to a rotating action for heavily-soiled loads such as industrial workwear, dustmats, mops and kitchen linen.

Another core feature of this tunnel washer is the Archimedean helix, which results in a robust drum with excellent rigidity and allows linen to be transfered be safely between compartments.

The transport scoop is designed so that the linen is not forced through a channel but falls freely into the next compartment.

The second development is the MediLine tunnel which was designed specifically for healthcare applications and complies with the EU Medical Device Directive.

Girbau is predicting three main trends for the tunnel washer.

The first is the ability to deal with different loads, including different colours and varying types of soiling and chemical treatments.

The second is that tunnel washer design is being advanced both by equipment manufacturers and by resource systems specialists, adapting products to make more efficient use of resources.

The third is greater control over the process to ensure good hygiene and disinfection. While temperature control will be key, other parameters such as alkalinity are also important.