Precise control greatly improves performance

11 December 2015



As laundries look to make themselves more competitive in the marketplace, they demand refinements that make the drying process even more efficient. Tony Vince examines current developments


Manufacturers are responding to their customers' concerns about reducing energy wastage and increasing efficiency. Visitors to this year's Clean Show in Atlanta were able to see for themselves the latest generation of energy-efficient tumble dryers.

Christophe Sisternas of Alliance Laundry Systems says that within Europe, there is a major drive to designing systems and solutions that use the least amount of energy but without sacrificing performance or quality. Managing the use of electricity and gas is the main contributing factor to the overall cost efficiency of the solution.
The physical cost of installation is also an issue, says Sisternas. Electrically-heated dryers can be expensive because of the time involved in installing the necessary circuitry and power breakers. Installing the central boiler, piping and ducting for steam-based systems can also be expensive.
"Gas dryers are currently the easiest to install and deliver the greatest energy savings," he says.
Alliance heat-pump dryers show how dryer technology is evolving. The latest Primus dryers, for example, require considerably less power to operate effectively (less than 4 kW, compared to 15 - 25kW for conventional dryers of the same capacity). They also consume 60% less energy, says Sisternas. The
heat-pump drying cycle is reasonably short. Depending on the model, it varies from 36minutes for the 9kg dryer to 58minutes for the 16kg dryer.
Modern drying systems are built to last, so unless a machine completely breaks down it is not often replaced. However, technology is being developed that enables the dryers to use less energy and deliver greater productivity and this is driving replacements.
Dryers now benefit from significant ergonomic improvements - working weight, tilting functions and sliding doors, for example - as well as features that deliver faster results, such as moisture control systems and a reversing drum that accelerates the drying process but avoids the damage caused by overdrying.
Auto lint filter cleaning and lower BTU units are also examples of how current technology can become quickly superseded by fresh thinking and innovation, says Sisternas. Washers that spin at a higher G-force also help to further improve productivity and reduce energy costs due to the lower residual moisture level in the linen that needs to be dried in the tumbler.
Alliance has made a significant investment in new management systems with dashboards to record and display drying cycles and key data such as the drying time, temperature and load. "This level of control is now being demanded by the best-performing laundries. It is why we have developed bespoke software, such as UniLinc and TotalVue for our Unimac OPL brand, that puts the laundry owner in total control," explains Sisternas.
Girbau of Spain has always emphasised that its focus is on solutions that help customers. According to Carles Solé, Girbau's product manager for its commercial division, reducing energy consumption and maintaining high standards of quality remain the two biggest drivers of demand for dryers.
The wider range of both articles and materials being processed today means that more customers are opting to replace equipment earlier, rather than continue to operate outdated, energy-wasting models.
Other factors have to be considered.There are more customers looking to wetcleaning, and this has increased sales of Girbau's ED series during 2015. The ED dryers provide total control over individual elements of the program, including speed, drum rotation and heating, to ensure maximum efficiency. The Transflow technology combines radial and axial airflow for maximum efficiency and drying throughout the drum, reducing cycle times and lowering energy consumption.
The ED dryers feature a highly reliable and accurate built-in humidity control system that automatically senses when clothes are dry and activates the cooldown process to maximise energy efficiency and protect the textiles by avoiding overdrying. It also allows gains in operational efficiency, which can be in the region of 25%, or considerably more when compared with older dryers. There are 10 pre-set programs to handle the most commonly laundered fabrics and new programs are also easy to set up. They can also be used for drying delicate wetcleaned fabrics.
The Jensen Group says that its latest JTD dryers can increase the laundry's flexibility in meeting the end-users' requirements. For example, loads might include delicate linen as well as contaminated pieces that could be infectious and therefore need to be processed separately. Nursing homes might want to clean personal garments separately from rental linen and in a different process. Designed for small to medium-volume loads, the dryers are best combined with the Jensen washer-extractors and areavailable in the same capacities. The JTD dryers are available in gas, steam or electric versions and can process volumes of 20kg (45lbs), 40kg (90lbs), 60kg (130lbs) or 110kg (250lbs). The fully insulated dryer features a reversing drum. More heat is transferred to the drying process by the specially designed large transfer and steam coils. The cooldown-process makes sure that energy is not wasted.
To further optimise the drying process, especially for linen categories that are processed with inconsistent batch sizes or moisture retention, InfraCare control is available for all dryers. This adjusts drying parameters based on the surface temperature of the linen and avoids overdrying. The Jensen dryer controls also offer a maintenance program so that cleaning and inspection services are carried out to keep the dryer in the best working condition.
Kannegiesser in Germany says that while the energy issue is not completely new, it has become more and more important. Although energy costs have gone down, dryers are intensive energy consumers and all customers have that in mind when they consider purchasing new dryers. Kannegiesser has launched the second generation of its PowerDry dryer range: the PowerDry D.II transfer dryer. This is available in gas and steam-heated versions, with a nominal loading capacity of 40, 60, 85, 120, 175 and 220kg. The PowerDry.II series also features Kannegiesser's Eco Air Circulation Heat Recovery as standard.
"Most of our new dryers are equipped with the Eco-2-Power package, and once the machines are installed and running we get an excellent feedback and a lot of repeat sales," says Joachim Rauschmaier, director of sales at Kannegiesser. Customers that operate PowerDry.II dryers with the ECO2power technology have reported remarkably low energy consumption, increased output per dryer due to faster drying processes, and a high consistency of the processes and the results. No specific additional maintenance is necessary to operate the dryers with this equipment.
Electrolux Professional says that in Europe particularly, customers are more focussed on the lifecycle cost of the machine rather than the investment cost. The company offers customers replacement cost calculators to show the savings they can obtain by exchanging their old machines for new energy efficient dryers. Reducing the energy consumption is more important than ever. The challenge lies in offering customers low energy dryers that do not compromise in terms of performance/drying time or in the quality of the machine.
"The importance of energy costs is expected to grow in the future and will become even more relevant," says Electrolux. "This is exactly that what our Line 5000 generation offers to our customers - maximum energy efficiency."
The dryers in the Line 5000 series feature the user-friendly and intuitive Compass Pro interface. The dryers also benefit from Residual Moisture Control, which measures the exact moisture content throughout the process, so ensuring a shorter drying time.
Jürgen Schäfer, Miele Professional's international director product management laundry technology, says that energy savings are extremely important in the energy intensive drying process. "We have different dryer technologies in our portfolio, from standard electric, gas or steam-heated dryers through to heat-pump technology or our H2O dryers that use hot water as the energy source," he says.
"The idea is to find out which dryer technology is the best for the specific customer requirements - for example, is it more important for the customer to reduce energy consumption dramatically or to achieve shorter cycle times?"
Miele's dryers combine low energy consumption (60% compared with conventional dryers) with simple installation, as they do not require a vent duct.
The typical Miele customer tends to think long-term, says Schäfer. If the benefit of a new product shows a real advantage in terms of energy savings, there is still a good chance that customers will review their options to improve their business's bottom line. "One way is to invest in new products - and certain customers adopt this approach." Schäfer adds that Miele's management control system for both washers and dryers improves data acquisition for its customers. "We think that transparency is the key for a laundry to optimise their processes and save money and time in the end."
At the Höltje Hotel in Verden, northern Germany, the in-house laundry is able to save money with a H2O dryer from Miele Professional. The process air in the tumble dryer is heated using 80C hot water from the storage tanks connected to the hotel's co-generation plant. These tanks store heated cooling water that is used for the Miele dryer at no extra cost to the hotel.
The Spanish manufacturer Domus, an Onnera Group member, specialises in the commercial and coin-op sectors. At Clean 2015 Domus was introducing its air recycling system for its dryers, and a drawer style lint filter, both of which had already been introduced in Europe.
Domus plans to introduce its latest heat pump dryers before the end of this year.
Knowing that dryers are one of the most energy-consuming machines in today's laundries, Domus designed its Eco-Energy series of dryers to minimise drying time and make energy savings of up to 40%. Domus has added a 24kg capacity dryer to its existing range of machines, which offers nominal loading capacities of 12, 18, 29, 37, 50, 67 and 83kg and is available in electric, gas or steam-heated versions
The Domus Eco-Energy dryer has a stainless-steel drum and features a frequency inverter as standard. All models offer reverse tumbling to encourage the movement of the textiles inside the drum. Its Air Re-cycle recirculation system returns expelled hot air to the machine directly through the back of the drum. The mixed axial-radial airflow provided by the Domus Double Flow system increases drying efficiency by improving the airflow inside the drum.
Efficient Dry is a humidity sensor developed by Domus that offers precise control of the moisture in the linen and avoids overdrying. The drying cycle will automatically stop when it reaches the set level of residual moisture. The drying system automatically adapts the speed of the drum to the humidity level of the load.
ADC in the USA offers a full range of tumble dryers that range in capacity from 12kg (25lbs) to 210kg (460lbs), available in gas, electric and steam options. It also produces specialty dryers, such as drying cabinets for firefighting uniforms and ULPA/HEPA dryers (ultra low penetration air/high-efficiency particulate air) for use in clean rooms. ADC has been manufacturing a clean room ULPA/HEPA portfolio of dryers since the early 1990s. Market demand has led ADC to focus on its 55kg (120lb) and 77kg (170lb) models, available in steam or electric versions. Energy consumption is always a consideration when replacing dryers, but the overall performance of a unit is also a strong influence in the decision-making process, says Nick Koukourakis, ADC's senior international sales manager.
"At the end of the day, a laundry manager is looking for the product with the highest standards of quality," he adds. In the main, laundries replace equipment because its maintenance and repair costs are increasing and indicate that it has come to the end of its life cycle.
"That being said, if there is a change in the type of linens bring processed and the current equipment is no longer meeting requirements - such as chemical injection during drying or variable speed tumbling - then laundries seriously consider buying replacements."
Uwe Stahl at Stahl in Germany says that having highest possible extraction without damaging the linen is the first step in reducing the linen's moisture before it goes to the dryers. Using the three important principles of efficient drying - high temperature, faster air flow and large surface area, Stahl's T series ensures that laundries can achieve best evaporation rates.
The dryers have a powerful exhaust system, which is 100% programmable, so it can meet most drying applications, from shorter drying cycles for towels to gentle drying programs for sensitive textiles.

CELEBRATING PERFORMANCE: Girbau this year created a limited and exclusive 55th anniversary edition of its ED Series dryers in addition to its HS Series, RMG Series and RMS Series washing machines

DRYERS


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