Patent EA-004915-B1 (EA)
Title: Improvements in and relating to the kilning of barley
Inventor: NALLEN PETER
IPC: F26B17/12
Filed: 2004-03-10
Abstract: 1. A continuous, kilning-process for germinated barley using a vertical kiln (1) having verbally spaced-apart air inlets and outlets (11) for the control of the temperature of the grain (25) therein, the arrangement of the inlets and outlets (11) being such as to allow the provision of heat treatment zones within the kiln, namely, an enlarged upper pre-heat treatment zone (5) forming a grain inlet and four descending heat treatment zones, namely, an initial heat treatment zone (6), an upper intermediate heat treatment zone (7), a lower intermediate heat treatment zone (8) and a lowermost final heat treatment zone (9)above a discharge outlet (19), the method comprising controlling the temperature of the air within the kiln (1) and the quantifies of air introduced and removed from the kiln (11), whereby a predetermined rate of discharge of the grain (25) at a desired moisture content is achieved, the method comprising: continuously adding the grain to the top of the kiln (1) over a larger area than that of the rest of the kiln (1) to ensure that most of the very moist grain (25) is close to the top of the kiln (1); delivering a main supply of pressurised hot air into the kiln (1) at the final treatment zone (9) in contraflow with the grain (25) to agitate and mix the grain (25) as it falls through the kiln (1); removing air from the kiln (1) for drying and controlling the air temperature as it travels up the kiln (1) and adding to or removing air from the kiln (1) such that the air in the pre-treatment zone is between 20 degree C and 45 degree C; reducing the moisture content of the grain (25) rapidly on introduction of the grain (25) into the kiln (1) to ensure that the grain (25), on discharge into the initial heat treatment zone (6), has a moisture content of between 33% and 37%; maintaining the air temperature in the initial heat treatment zone (6) at between 50 and 60 degree C and the grain moisture content at between 23% and 30% on discharge; maintaining the air temperature in the upper intermediate zone (7) at between 65 and 73 degree C to ensure a grain moisture content of between 10% and 14% on discharge; maintaining the air temperature in the lower intermediate zone (8) at between 68 and 75 degree C and the grain moisture content at between 5% and 8% on discharge; introducing air at between 75 degree C and 90 degree C into the final heat treatment zone- (9) to ensure a grain moisture content of between 4 and 5% on discharge; and continuously removing grain (25) from the kiln (1). 2. A kilning process as claimed in claim 1, in which the air temperature in the pre-treatment zone (5) is of the order of 25 degree C and the discharge moisture content of the grain is of the order of 35%. 3. A kilning process as claimed in claim 1 or 2, in which the air temperature and discharge moisture content is of the order of 55 degree C and 27%; 68 degree C and 12%; 70 degree C and 6%; and 81 degree C and 4.5%; for the initial, upper intermediate, lower intermediate and final intermediate zones (5. 6, 7, 8 and 9) respectively. 4. A kilning process as claimed in any preceding claim, in which the air temperatures are so controlled as to ensure that the kilning process takes not less than 20 hours and not more than 24 hours. 5. A kilning process as claimed in any preceding claim, in which on start-up and with the kiln (1) empty, the steps are carried out of: green malt is delivered into the kiln (1); air is delivered into the final zone (9) and the grain (25) treated as if in the pre-treatment zone (5); when the grain in the final heat treatment zone (9) would be ready for transfer normally to the initial heat treatment zone (6), the batch in the final heat treatment zone (9) is heated as if it were in the initial heat treatment zone (6) and the batch in the lower intermediate zone (8) is treated as if it were in the pre-treatment zone (5); and the process is repeated progressively up the kiln (1) until the grain in the final heat treatment zone (9) is ready for discharge when the process is carried out as in any preceding claim.