GRAIN drying is a simple process, according to Agridry Rimik Pty Ltd director Tom Fusse, whose Toowoomba, Qld, based company has long experience in drying a range of seed crops. "Simple, but it affects the whole crop harvesting process," Mr Fusse said. "At the CBH receival limit of 12 per cent moisture for every 100 tonnes of grain, there's 12,000 litres of water present. We are asking the dryer to remove water, not dry the grain. "Grain drying puts you in control of your harvest. No dryer can mean no harvest." Points made by Mr Fusse included: pryers increase your harvesting capacity; pdryers cost less than headers (a dryer plus a small header require less capital expenditure than a large header); pdrying can give you a $30/t advantage in grading quality; pdryer operators harvest earlier and have more hours a day spent harvesting; pdrying equates to good crop harvesting management; pthe bigger the bulk storage bin, the bigger the expectation of pockets of varying moisture levels occurring in it; and pdryers are simple machines featuring a long life and low maintenance costs. "All we are trying to do is take the water out," Mr Fusse said. "There is no dry matter loss in the grain itself. You are not losing grain weight. "It is important to have a dryer which dries in a predictable way. Control systems are constantly improving. The difficulty in drying is you can't see what's going on or measure it. "All dryers have a flow management problem. You have to decide where your dryer fits into your total harvesting system." Mr Fusse said dryer fuel consumption was greater in cold weather. Drying barley at 20t/hr under average conditions could consume six litres of LPG, or four litres of distillate. High drying and storage temperatures were to be avoided at all costs if grain quality was to be maintained. Grain was "safe" stored at 5-10°C. "Most of our grain storage problems are caused by high temperature. Your aim should be to cool the grain," Mr Fusse said. "Many silos used in drying storage do not have a roof vent to allow the moisture to escape." CSIRO stored grain research officer James Darby, Canberra, said moulds were generic to all grains. "Barley grain viability and mould formation depend on temperature and moisture content and the grain's duration in the bin," Mr Darby said. "A problem is how to cope with designing a way of drying grain in the top layer of the bin. Another is how to hold grain at 16pc moisture for eight weeks and avoid moulding." Issues that had to be addressed included the safe storage time for barley at various moisture and temperature levels before drying was required, heating and spoiling losses, and mould. "Getting the messages across to those not here is important," he said. Mr Darby said there were many aeration system designs. Among the engineering issues were establishment costs, project timing, capacity, logistics, handling methods, site utilities, efficiency and user interface. Operation issues included loading, handling, ducts, safety, convenience, user friendliness, controls and hygiene. "My observation here is that local growers require a very big data source," Mr Darby said. "Weather conditions for drying may not be favourable if the outside air is wet. The key factor remains aeration." Mr Fusse said aeration of grain looked simple but it was complicated to manage well. "If you manage cooling, you're managing drying. If the air is wetter going out the top of the silo, drying is taking place," he said. "CSIRO monitoring using wet bulb principles on cooling and aeration has led to major advances in the past 20 years." Graingrowers Dick Kuiper, West River, and Neville Welke, Esperance, described the installation and operation of their on-farm dryers.