In the development of hay drying systems for high-quality hay, Reindl Kältetechnik focused on system development and drew upon the help of specialists from other fields in order to acquire the required niche expertise. “We learned so much about grass and hay,” admits Wolfgang Reindl, refrigeration industrial engineer and managing director of Reindl Kältetechnik, “before getting a grip on the dehumidification process. There were also a few surprises concerning the raw materials, and they had to be taken into account during the processes.” Indeed, now the installations are working with maximum reliability, are user-friendly, extremely energy-efficient, and can be optimally adjusted to the size of the company. The dehumidifiers are available in a total of seven performance ranges. Centrepiece of the installation: optimal dehumidifying and reliable service In the dehumidifier, which in theory works like a big heat pump, the first heat exchanger removes the moisture by cooling the air, and collects the water on the ground. A pump then removes the water from the system. In the second heat exchanger, the dehumidifier heats the air again to increase its absorption capacity for water va- Hay drying machinery – advantages for farmers and cattle But why a hay drying machine? Hay is the foundation of cattle feed in the colder seasons. The more carefully the farmer can dry the hay, the better its quality will be. The quality also depends on the exact time of the harvest. If the hay harvest is not timed exactly, the yield of the dairy cattle can decrease from 15 l/day to 5 l/day. Machine hay drying provides a range of advantages: The harvesting process is less dependent on the weather, and therefore easier to plan. More of the nutrients remain preserved in the hay whereas additional feeding with concentrated feed significantly reduces them. This is a considerable cost advantage of machine-dried hay. The animals are also healthier, the vet bills lower and the milk production the same as for the winter feeding. The quality of the hay is clear to be seen: even after drying, it preserves a colour and smell that makes it seem freshly mown. This also attests to the hay’s nutritional value: The hay dried with the Reindl product reaches 7.2 NEL - an absolute peak value. Also on the technological front, there are definite advantages to be reaped from hay drying with the Reindl Kältetechnik dehumidifier: Structure of a hay drying system After mowing, once the grass has been lying for a short while in the fields, the farmers bring it into the barn. A distinction can then be made between the hay that remains directly in the dryer, which then serves as storage at the same time, and that which is subsequently relocated for contracted drying. In the hay dryer, the hay lies on an air-permeable intermediate floor, through which the dry, warmed air travels and then rises up throughout the hay. The air absorbs the moisture released by the gas. Via ventilation flaps, the now moist air reaches a further intermediate floor under the roof, which takes it to the dehumidifier. Due to the sophisticated airflow system, high drying rates and high process efficiency are achievable. The centrepiece of the entire system is the dehumidifier, the design of which has a definite effect on the function and efficiency of the system. Here, Reindl primarily calls on his invaluable knowledge of the processes which occur during drying, to guarantee a seamless and lastingly effective service. On many farms, only limited power is available. Using the VLT® frequency converter, Reindl is able to limit the inrush current efficiently despite full torque at power up. The overall control, which is optimally adjusted to the size of the operations, ensures higher energy efficiency, for example by controlling the ventilation flaps at the intermediate floors. Via ventilation flaps, installations can use or offset the various temperatures depending on the outside temperature and the amount of sunshine, in order to achieve the best possible process. Using the lost heat and process heating to warm the dry air increases the efficiency of the system further. 2 Danfoss VLT Drives · DKDD.PC.105.A1.02
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