Heavy duty, light on energy – and very smart, too19 October 2018
A new generation of smart heavy-duty tumble dryers that are light on energy use and easy to operate has recently come on stream from major manufacturers. Kathy Bowry reports
One of the banes of a launderer’s existence is the problem of over drying linen and to this effect two of the giants of the laundry equipment world, Jensen and Kannegeisser have made strides to combat the problem.
Jensen, which is taking a break from ExpoDetergo this year after fielding its own Performance Days event in Mallorca in May, in its promotional brochure humorously invites prospective buyers to ‘enjoy the dry season’. The comment references its Transfer WR 60-120 dryer range which, says the company, is the most energy efficient dryer in the world at 0.95kWh/l. It claims up to 15% energy savings over conventional models and up to 10% higher evaporation capacity. Thanks to shorter drying times, productivity is increased and energy efficiency is drastically improved, according to Jensen’s Gerda Jank.
She explains that newly developed frequency-controlled high-performance fans and optimised drum geometry improve the air flow and the heat distribution in the drum, resulting in outstanding energy balance and consistent, reproducible drying results. The frequency controller for the fans and the individual, process-based control of air quantities guarantee extremely low-wear operation of the fan motors. The new automatically controlled circulation flap continuously regulates the optimal ratio between fresh air and circulating air quantities depending on the degree of dryness of the goods and the individually adjusted program. In order to increase the benefits, a compact plate heat exchanger that can be fully integrated in the dryer housing is available. In addition, WR dryers are very well sealed, which prevents escaping air and facilitates low heat emission and a low noise level.
The large diameter of the drum enables an optimal fall curve and guarantees an outstanding air flow through the laundry so the finish quality is improved considerably by preventing wrinkling and tangling of large laundry items. The integral InfraCare control unit continuously measures the exact temperature of the laundry load by means of an infrared sensor. Meanwhile, Kannegeisser’s PowerDry and compact dryer DC, in both steam and gas versions, have been developed to guarantee consistent heat distribution over the whole drum depth. Radial air flow assures maximum air contact between drying air and linen. Kannegeisser claims lowest energy consumption on the machines withECO2 power system which measures inlet air, exhaust and textile temperature (InfraTouch)and the position of the air flap. Control of heat supply, air circulation rate, linen dropping curve (which is revolutions per minute adapted for free movement of linen). The result, says Matthias Schaefer at Kannegiesser, is 1.1 kWh energy consumption, shortest drying time and best textile care by avoiding over-drying. “ECO2power = eco/power. The two can work together giving low consumption and high performance,” he says.
When Lapauw took over Transferon, says Steven Renders, the company’s CEO, it opened a door to offering a vast range of heavy duty dryers: from 60 kg up to 200 kg capacity, steam and gas heated.
“The dryers can be integrated into a tunnel washer-installation but the beauty is that they can also be used as a stand-alone solution, which allows us to offer an industrial dryer to laundries that need a stand-alone solution for their heavy-duty work,” he says. “The dryers are designed with the lowest Total Cost of Ownership in mind: simple measures, like drum drive wheels that are mounted outside of the frame (and heat) and assure low maintenance costs or upward closing drum doors that prevent air entering the drum, assure maximum efficiency a.”
Lavatec’s contribution to efficient drying comprises industrial laundry dryers (10-270 kg). “We have for example, with our transfer-batch-dryers introduced a number of design and process improvements to bring the laundry several benefits including better finish quality and increased operating profit,” says a company spokersperson.
“In our gas-fired transfer-batch-dryers, air recirculation is a standard feature. It increases the efficiency as well as improving the finished result. By direct infra-red measurement of the linen surface temperature, in combination with sophisticated dryer control and our specially designed burner, we achieve the shortest possible drying times with very low energy consumption.”
Stahl’s T-series offers a wide range of commercial tumble dyers with a capacity of 8 - 90 kg for a wide variety of requirements. “In addition to the quality of the results, flexibility, cost-efficient operation and ease of use are key criteria for laundry operations,” says Uwe Stahl, managing director of the traditional family business in Sindelfingen, Germany. “We offer products that work quickly, reliably and, above all, cost-effectively, without sacrificing the result.”
The Stahl T-series is produced in different designs and sizes, and in electric, gas, thermal oil, steam, steam/ electric reversible as dual heating system and hot water options. “The type of fresh air intake is variable. In operation, the machines consume only as much energy as is needed for the current drying process. In addition, Stahl dryers with recirculating air recovery ensure only moist air is removed, while warm air is returned to the drying process. In total, 60 %of the exhaust air is recycled, which is reflected in savings in consumption and drying times. Another energy-saving factor is the integrated plate heat exchanger. The radial air flow ensures even heat distribution in the drum: Drying is faster and without overdrying.”
Turkish company Tolon manufactures a robust and industrial dryer range with capacities of 20 and 110 kg, with a, space-saving sliding door system.
“Thanks to this feature on Tolon’s TD range, in combination with our exhaust to the top, the space needed in a laundry to install the dryers has been reduced to a minimum and allows for adjacent placement. All our dryer models, available in electric, gas or steam heating, are standard equipped with a stainless steel reversing basket. The inverter drive offers the possibility to adjust the speed according to the dryness level, which makes them more efficient and reduces the total cycle time,” says a company spokesperson.
“Saving dryer time can also be achieved with our heat recirculation option, as part of the heated air is brought back into the drum for faster drying. The direct air flap on our steam models allows for fast cooldown and we can offer a high-pressure steam coil up to 12 bar for heavy-duty applications.”
According to Steven Renders, Lapauw CEO, cleanroom laundries used to buy off the shelf dryers and modify them but that is not their core business. “So, we sat together and shared our know-how and experience to create the Medistream, the first dedicated cleanroom dryer.”
The Medistream cleanroom dryer, like Lapauw’s Mediwave barrier washer which the dryer complements, has a GRP (Glass Reinforced Polymer) cover. “The monolithic shape and smooth surface, with no sharp angels, crevices or joints leaves no opportunity for dirt or soil to build up and it is easy to clean. On top of that, the coating contains Titanium Dioxide (TiO2) nanoparticles that have anti-bacterial properties.”
The Medistream not only has a fully enclosed drum to assure complete insulation but also has a cantilevered drum, instead of the conventional drive wheels under the drums, to prevent creation and emission of additional dust and lint.
“Of course, the Medistream has a HEPA-filter, but it is mounted behind the heating element, instead of in front of it. Together with the general particle filter, that is mounted in front of the heating element, the HEPA filter forms a double layer, assuring maximal filtering efficiency,” says Renders. A permanent connection for particle counter in the exhaust gives operators the opportunity to continuously measure the particle count of the contents.
With a drum volume of 1,410 litres, the Medistream complements the 60 kg - 100 kg barrier washers that are generally used in cleanrooms.