Tunnel vision

20 April 2017

Tunnel washers have come a long way in recent years with manufacturers fine honing both the physical design and the technologies that make them a force to be reckoned with in the modern laundry. Kathy Bowry reports that the quest for even better performances continues

Recent developments in tunnel washers, or as they are also called, continuous batch washers, have opened up a new world of opportunities for operators allowing for more flexibility while at the same time coping with specialisms. The opportunities for utilities savings continue to improve and the major players in the market are committed to pushing the envelope even further with continuing R&D investment. We previously reported that developments in tunnel technology have opened up new opportunities for tunnel washer manufacturers. Is this still the case?

The answer to that is a resounding ‘yes’ from Dani Arcarons, tunnel washer supremo at Girbau,  who tells LCNi: “The challenges we are facing (the depletion of natural resources and climate change) results in constant pressure for improvement in efficiency and a reduction in the consumption of water and energy. Now we know that this struggle will never be over. The manufacturers that want to survive in the long term must be continuously moving. This struggle translates into a constant improvement, without revolutionary changes, but which is nevertheless of great importance. If we compare the current situation with three years ago, the change is very significant.”

Matthias Schäfer, laundry logistics manager at Kannegiesseur responds: “The individuality of customer demands rises constantly. With the Kannegiesser batch washer it is possible to treat every batch totally separately like in a washer extractor. This can only be achieved with washing and rinsing in standing bath operation. The amount of water, chemicals and even the temperature can be adjusted per batch and is reproducible at any time. There is no mixing of liquor between neighbouring batches during the whole operation. This gives you the flexibility you usually only have with washer extractors.

“The maximum usage of machine volume is a decisive factor for both output and wash quality. The Kannegiesser ActiveDrop principle stands for excellent wash mechanics and consequently for better wash quality.  As a result tunnel washers can replace washer extractors with lower consumption, less labour needed and even better wash mechanics.”

From an engineer’s perspective Yves Dabrowiecki of Milnor says: “Indeed, today a modern double drum modular Milnor CBW® can and does wash everything that needs to be washed , from  normal hotel  and hospital linen, to heavily soiled workwear, through dust mats, to extremely polluted and dirty cleaning rags.

Meanwhile Keith Ware, vice president, sales at Lavatec, comments: “With the ability to change water flows, drain and fill in modules, Lavatec has placed tunnels in food and beverage plants, uniform plants, and recently developed a tunnel for bar towel washing for a large customer. We have also had our tunnel tested as a dye machine, providing lower costs and higher throughput results than standard dye machines. Older tunnel designs were not capable of processing these varying types of products. This segment, along with reduced water usage, provides an expanded market.”

Over at Jensen, communications manager Gerda Jank explains: “There are various linen types which determine the tunnel washer configuration, such as healthcare linen and linen for nursing homes, hospitality, industrial uniforms, dust mats or cleaning mops. All these different types of linen require a special process.

“Uniforms or industrial workwear might require extra bath exchange facilities in the pre-wash or more wash beaters for more mechanical action. Dust mats with a lot of sand and particles need special recovery tanks to collect the residual dirt. Light and voluminous items like underpads from hospitals or nursing homes are often underloaded which has an impact on the machine capacity and therefore the size of the tunnel washer. This is also valid for polyester and blended fabric items.”

Food and beverage work

Some manufacturers suggest that industrial and food and beverage work can now be as successful in a tunnel system as in washer-extractors and it’s a claim with which Ware concurs. “Yes, this is possible due to standing bath systems which can drain and fill in the same module, thus allowing coloured linens to be washed without leaving multiple open products between colours.

“In order not to increase water consumption when draining specific colored linen modules, Lavatec has utilised multiple storage tanks to hold water based on colour or light and dark goods, which can be brought back into the tunnel when the appropriate goods are being washed. This prevents the water from going down the drain, which would increase overall water consumption.”

Arcarons believes the benefits of the batch washer (efficiency and large production) are interesting for many sectors. “Current tunnel washers are highly versatile and they can adapt to suit different processes and types of linen. Most of the time it is our clients who, in order to grow and diversify their production, ask for machines that can process different types of linen and that are easy to use.”

Schäfer cites the repertoire of Kannegiesseur’s technology in this instance saying: “With the washing principle, ActiveDrop, the highest wash performance and textile care are the focus of the washing process. The larger volume of the batch washer compared to washer extractors is optimally used to guarantee the perfect mechanical action for the batch. The ActiveDrop contains four steps: Lift → Throw → Compress → Flowthrough.” He explains that the large ribs lift the linen even higher than in conventional batch washers ensuring a dynamic throwing of the batch. Straight drum walls give the linen enough space to move freely and minimise tangling of the articles. The large drum diameter allows a high drop height so the linen can be optimally compressed. Moreover the frequent changes of direction enable a constant linen turnover for permanent flowthrough and therefore efficient wash action. The wash liquor penetrates deeply into the fiber without friction on the textile surface. This is what a washing principle has to focus on.”

Milnor’s Dabrowieck chips in saying food and beverage work is best served with a small tunnel system explaining that Milnor has been selling three and five module tunnel washer systems since 1991,” basically since the introduction of our centrifugal extractor”.

“The trend for smaller and medium sized laundries to replace washer extractors with small CBW batch washer systems has increased for Milnor during the past few years, especially since the Milnor PulseFlow machine has been introduced. The most popular machine is a five compartment 50 kg model generally equipped with a centrifugal extractor, because it is compact and customers can use existing dryers instead of immediately automating the system. This keeps the initial investment to an affordable level.”

Jank of Jensen also agrees that tunnel washers lend themselves to F&B work – and a whole lot more besides. “The linen volume to be processed determines the machine size. This leads to a certain batch size and number of compartments, and with a very high linen volume, two or more tunnel washers are the right choice. For small batch sizes, a Senking Universal tunnel washer P 36 processes 36 kg/80 lbs per hour, the largest volumes of 120 kg/260 lbs are handled with the Senking Universal MaxiLine.

 “Uniforms or industrial workwear might require extra bath exchange facilities in the pre-wash or more wash beaters for more mechanical action. Dust mats with a lot of sand and particles need special recovery tanks to collect the residual dirt. Light and voluminous items like underpads from hospitals or nursing homes are often underloaded which has an impact on the machine capacity and therefore the size of the tunnel washer. This is also valid for polyester and blended fabric items.”

Strong sector demand

Girbau chalks up 2016 as the year of the consolidation of traditional market recovery and a strong growth in the emerging markets. “Major trends favour industrial laundries, for instance we see tourism as an instrument for development in emerging markets. Batch washer facilities always have the benefit of low labour costs and great efficiency in water and energy use,”says Arcarons.

According to Milnor’s Dabrowiecki, growth is more visible in the USA and Asian markets. He noticed a slow down on the European market in 2015 and 2016. “Hopefully 2017 will be better”, he adds hopefully. Meanwhile, Ware comments on behalf of Lavatec: “Healthcare remains strong as consolidation of smaller laundries occur or hospitals outsource linens to commercial providers. Hospitality is strong in some markets where hotel growth has been picking up, such as in Orlando, Las Vegas and New York. Many hotel operators are also eliminating in-house laundries to free up space or reduce capital expense as their current laundries are in need of replacement.”

Conserving resources   

Arcorans comments: “Saving on water and energy is very important, not only due to the world’s physical challenges but also because of laundry operating costs. Savings and efficiency are the main concern of our customers. The costs of resources that have been kept low since 2008, now start rising. However the prices for clean linen have not increased. So, at Girbau we are focused in supplying highly efficient machines and installations with very low operational costs.”

Jank forecasts that energy and water savings will become more and more important as resources are limited and will become more expensive. “This will also affect the profitability of the laundry. To keep the water consumption low in spite of frequent color changes in the process, additional recovery tanks for a separated reclaim of white or colored water in large dedicated buffer tanks is an advantage.”

Dabrowiecki deliberates: “For the tunnel itself the focus is still on water and energy savings. With fresh water consumption of 2.5 – 3 l/kg a limit has been reached. Further reduction while possible requires technical involvement to an extent that the savings at this moment cannot justify the investment. Energy savings are achieved through various means, low temperature washing, steam-less applications, better insulation of the heated zones. Looking at a complete tunnel washing system there are considerable savings using high pressure water extraction devices and dryers with advanced drying technology. The Energy Saver Seal that Milnor has used for many years in its dryers is a good example to reduce waste of energy. Modern burner technology for gas-heated dryers, modulating burners, heat recirculation and drying end point determination and insulation  have all made dryers much more efficient than they ever were.”

Ware asks the question: “Are laundries perhaps more interested in capacity over reducing consumption?” His answer when it comes to the USA market: “There was high interest in water consumption in the western US as the multi-year drought continued to impact California and other states. With the recent high precipitation levels they experienced in December and January, it may reduce the interest in lowering water consumption, or the push by states for mandated reductions. Most laundries look to be environmentally conscious, but this is driven by cost savings and improved quality. Without mandated limits on water, sewer or carbon emissions, laundries look to be green as long as it improves the amount of green going into their wallets.”

Tunnel washers

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