The German Cogeneration Act (KWKG) has been designed to promote the use of self-generated energy. In resin drying, this potential often remains unused, because high energy investment is necessary during plastic processing. With desiccant dryers, for example, drying air is generated by a desiccant which must subsequently be dehumidified again by means of heat. This heat is partly released to the environment, while the remaining part is used to heat up the drying air. During this, the topic of energy recovery or energy saving is excluded. On the contrary, the CARD compressed air dryer series from the FarragTech GmbH functions according to the principle of the tried and tested dual-circuit compressed air principle and can be additionally combined with a compressor as well as a heat exchanger. That way, energy can be efficiently saved and a reduction of operating costs can be achieved. On this year’s Fakuma trade fair in Friedrichshafen, the new CARD R system will be presented for the first time.
With desiccant dryers, complete energy recovery is often dispensed with, because the recovered heat is already partly used to heat up the drying air. That is why compressed air dryers working according to the dual-circuit principle are offering a large number of advantages: Compared to a simple dehumidification unit, using this new system from FarragTech, with a capacity of the drying hopper of just 40 litres, 1 kW energy can already be saved due to the lower compressed air consumption. The average saving potential is almost 70 percent, because the resin to be dried is preheated in the upper part of the hopper due to heated ambient air. The actual drying process takes place in parallel to the lower part so that only about 30 percent of the otherwise required compressed air is required in contrast to pure compressed air dryers at the same material throughput.
Efficient recovery of waste heat
The CARD R system from FarragTech is a further development of the CARD M/L series and is supplied with a stand-alone compressor, the heat of which can be reliably recovered. During the process, waste heat is recovered via oil or air heat exchangers with approximately 80 to 90° C. The heat exchangers themselves are directly integrated into the housing of the air compressor. By means of this energy, the air is preheated in the secondary circuit with the CARD M and L. That is why clearly less additional heat output is needed in order to heat the air to the required drying temperature. If drying takes place at 80° C, for example, which is the case with materials such as polyamide or ABS, then no additional heat output is required. Thereby, the following applies: The better the air compressor is utilised, the lower are the costs per Nm³/h of air. With low take off, more energy is thus required to generate compressed air than with higher utilisation.
Another advantage of the new CARD R is that the system is individually designed for each customer: Depending on the individual requirement, a suitable concept is made according to which the compressor size is calculated for the CARD R.
On the Fakuma 2017 in Friedrichshafen, the new system from FarragTech will be presented to interested visitors in Hall A3, Booth 3205. Employees of the company are ready for first conversations and concrete inquiries.
Further information is available on www.farragtech.com