Much of the recent development in the tunnel washer sector has been centred on improving wash efficiency, and reducing costs.

The re-use of water has been a frequent theme, reducing the amount of fresh water needed, Kannegiesser in Germany says that a specific aim has been to make more efficient use of the wash water.

When linen transfers from compartment to compartment and into the extraction unit, around half of the liquor is still adsorbed in the batch. On average this amounts to 2litres per kg linen and it will include not only the water itself, but also some heat and the residue wash chemical. The aim should be to remove this liquor prior to the rinse and then re-use it in following wash cycles.

This has been achieved in the latest development of its PowerTrans system – the PowerTrans Jet.

The PowerTrans batch washers with their choice of bottom transfer, oscillation action or top transfer, rotating action variants, large drum diameters, and straight panels have already achieved wash and rinse systems comparable to that of a washer-extractor, according to Andreas Langer, a member of the wetwork equipment sales team.

However, washer-extractors extract most of the adsorbed wash liquor by pre-spinning before the rinse cycle begins. This has not possible in a tunnel washer until the development of the PowerTrans Jet system. This integrates the extractor into the body of the machine and allows the pre-extraction of the free water and adsorbed main wash liquor.

Langer says that the advantages of the Jet system are:

• optimised rinse results due to pre-extraction up to 800G;

• that the pre-spin leaves only the remaining adsorbed liquor to be rinsed out;

• the compressed textiles adsorb the rinse water in a short time, acting like a squeezed sponge;

• shorter rinse time – the process of pre-spinning, rinsing and final extraction is carried out within a total cycle time of no more than 5minutes;

• the rinse process can be repeated exactly – without any compromises;

• maximum possible re-use of the hot main wash liquor and the chemicals it contains.

Langer explains that the main wash liquor is extracted with up to 800G. “The compressed textiles will adsorb the fresh water of the following rinse process in an extremely short time. In most cases, 3litres of fresh water per kg loading is sufficient to dilute the remaining adsorbed liquor – the dilution factors are considerably better than with common rinse processes.”

During the rinse process, the spinner reverses like a washer- extractor. Speed, time and reversing intervals are freely programmable depending on the classification of the textiles. Final extraction is also freely programmable, up to 800G.

Langer says: “The main wash water collected in tank 1 is still enriched with active washing chemicals and can be used for further washing processes – giving energy savings without the need for a heat-exchanger.

“Rinse water collected in tank 2 is significantly colder and can ideally be used for pre-wash processes – even in the case of washing linen with protein stains,” he adds.

Designs for different needs

The need to control operating costs is cited as one of the most important concerns for the laundry industry by Jensen’s Kathrin Scheffel.

The Universal and Universal SL have established the principle of re-using water. The Universal re-used water from the press or centrifuge and the rinse water as flush water for the first compartments in the pre-wash zone, and the SL took this further with a closed system that pumped the water directly through a self-cleaning pipe to the programmed destination. This closed system avoided the need for re-use tanks that needed to be cleaned, and led to improved hygiene.

The company now has six different types including, in addition to these two machines, the EasyLine, MediLine, CompactLine and the HighLine, which, with its choice of oscillating or rotating action available in one machine, allows the action to be matched to the load.

Scheffel notes that her company designs machines to suit the market trends in various countries.

In Australia, an acute drinking water shortage has led the government to require companies to make water savings. Tunnel washers are equipped with re-use systems and operated with consumption below 5litres/kg. The eight-compartment CompactLine has proved popular.

The USA market is focussing more on tunnels as water and energy savings are becoming more important especially in dry states such as California and Nevada. Even workwear is being processed more and more in tunnel washers to achieve lower water and chemical consumption, increased production and labour savings. There is also greater interest in larger compartments from 50kg upwards.

Northern Europe is seeing a move to more stringent hygiene standards that spreads beyond the hospital sector.

In Germany, laundries demand the highest productivity combined with low consumption of water, energy and chemicals. However, many laundries also process a huge product mix with different colours or fabric types. More and more machines have been designed with complete bath separation, including in the rinse zone.

Flexibility required

At Girbau, the need for laundries to reduce costs and increase profitability is seen as just as important as cutting water and energy consumption.

It is this need for flexibility that is a key feature behind the development of the TBS50 batch washer system, which was designed to meet the dual goals of efficiency combined with maximum profitability and minimum environmental impact.

It has an inner and outer drum module to allow the system to be easily adapted to suit different washing requirements. Water and energy consumption are already low, but Girbau continues to research ways to further reduce these levels.

The company has installed a batch washer laboratory in its heavy-duty production centre.

The TBS50 has a wide range of program options to make it adaptable to different requirements, and the company attributes the machine’s success to this feature combined with its mechanical options.

The batch washer settings can be customised to meet specific process requirements. The system’s water inlet and outlets, chemical products and steam can be set in each of the operational modules.

A recent installation in Germany provides an example of how this works. The customer treated a wide variety of linen, which required completely different washing processes. The system as installed allows pre-wash (variable), wash (variable), rinse (variable) and strong rinse (variable). Other examples of how this eight-module batch washer can be set are shown on p25. The operator can choose between the various possible configurations, and while only three solutions are shown in this example, the system allows for more.

Girbau says less water is consumed as the rinse cycle re-uses water.

This reduction in water consumption also leads to a reduced use of chemical products.

Increased thermal insulation results in lower energy use and also means that less water needs to be heated as the water used in the wash cycle has already been partially heated during the previous phase.

Handling large volumes

According to Rick Kelly, vice president of marketing and sales administration at Pellerin Milnor in the USA, many businesses with on-premises laundries are outsourcing their goods in an effort to streamline their efficiency.

“This means that large laundries are getting even larger to respond to increased demand,” says Kelly.

This growing production at larger commercial laundries has prompted Pellerin Milnor to add larger-capacity machines to its range of automated CBW tunnel washers.

The company now offers the 92048 CBW washer with a rated batch size of 115kg (lb), and claims this is the world’s largest capacity tunnel washer.

Described as ideal for laundries with high production requirements and limited floor space, the 92048 CBW washer can be designed for a variety of washroom applications.

It processes any type of linen including sheets and towels and can also cope with heavily-soiled goods such as bar mops, floor mats, industrial uniforms, shop towels and kitchen linen.

The washer has a top-transfer design – a perforated scoop lifts each batch out of the water and transfers it to the next chamber. This allows almost all of the “free water” (the water not trapped in the goods) to flow back into the original module so that it is not carried forward with the load.

The washer also features solid, fixed partitions that keeps all baths completely separate.

There are no seals beneath the water line to wear and leak and no perforations in the partitions, so that bath integrity is maintained at all times.


Eight-module Girbau TBS50 set-up

Eight-module Girbau TBS50 set-up
Eight-module Girbau TBS50 set-up
Eight-module Girbau TBS50 set-up