and widely available from the major oil companies as a by-product of renin he combustion equipment, comprising a series of burners in an insulated chamber, thermostatically controlled and with air and flame failure safety devices built in, is relatively cheap to install and maintain Natural gas has similar favourable combustion characteristics but may not be so readily available in rural areas, and a special run of mains from the nearest pipeline may involve considerable installation outlay. tonne,. A Through Conveyor Band Dryer with a raw material throughput of3 per hour would require a combustion unit for propane with a maximum rating of 15 million Btu's per hour. This would call for a seven burner chamber, five burners firing continuously with two on thermostatic control. Satisfactory flame conditions can be maintained with propane at a regulated pressure of 0.95atm and, whilst the fuel consumption will obviously vary in accordance with the evaporative duty demanded, this could be roughly taken at 140kg of LPG per hour, or 36cu m of natural gas The oil industry, in collaboration with the UK Factory Inspectorate and other experts, has laid down a Code of Practice in relation to the storage and commercial usage of liquid petroleum gas, and the processor intending to use this type of fuel should familiarise himself with the regulations, particularly as to storage tanks and pipelines. Where LPG storage tanks cannot be sited at least 15m away from the factory buildings, and 15m away from the nearest roadway, they will almost certainly have to be installed nderground, and such installation is relatively expensive compared with ground level tankage. Whilst Propane will vaporise naturally from an overground installation, such is not the case from an underground tank. Here the liquid propane has to pass through a steam heated vaporiser to convert it to a gas. Very low temperatures prevail in an underground tank, as vaporisation takes place; these are not relieved by a relatively high ambient air temperature as in the case of an overground installation, hence the necessity for assisting vaporisation by supplementary steam heat. Tank pressure will be 4.5 to 6. atm and this is reduced to 1. 36atm by regulators on the pipe main to the combustion plant, where the gas pressure may be further reduced to suit required combustion conditions and drying requirements Indirect The indirect system can be applied in several ways, and with some types of dryer there is no alternative method of heat transfer to the product The Through Conveyor Band Dryer can derive its hot air supply from a heat exchanger used in connection with an oil or coal-fired furnace. The heat exchanger comprises a set of cast iron or steel elements or plates, usualland widely available from the major oil companies as a by-product of The combustion equipment, comprising a series of burners in an insulated chamber, thermostatically controlled and with air and flame failure safety devices built in, is relatively cheap to install and maintain. Natural gas has similar favourable combustion characteristics but may not be so readily available in rural areas, and a special run of mains from the nearest pipeline may involve considerable installation outlay AThrough Conveyor Band Dryer with a raw material throughput of 3 tonnes per hour would require a combustion unit for propane with a maximum rating of 15 million Btu’s per hour. This would call for a seven burner chamber, five burners firing continuously with two on thermostatic control. Satisfactory flame conditions can be maintained with propane at a regulated pressure of 0.95atm and, whilst the fuel consumption will obviously vary in accordance with the evaporative duty demanded, this could be roughly taken at 140kg of LPG per hour, or 36cu m of natural gas. The oil industry, in collaboration with the UK Factory Inspectorate and other experts, has laid down a Code of Practice in relation to the storage and commercial usage of liquid petroleum gas, and the processor intending to use this type of fuel should familiarise himself with the regulations, particularly as to storage tanks and pipelines. Where LPG storage tanks cannot be sited at least 15m away from the factory buildings, and 15m away from the nearest roadway, they wiU almost certainly have to be installed underground, and such installation is relatively expensive compared with ground level tankage. Whilst propane will vaporise naturally from an overground installation, such is not the case from an underground tank. Here the liquid propane has to pass through a steam heated vaporiser to convert it to a gas. Very low temperatures prevail in an underground tank, as vaporisation takes place; these are not relieved by a datively high ambient air temperature as in the case of an overground installation, hence the necessity for assisting vaporisation by supplementary steam heat. Tank pressure will be 4.5 to 6.8atm and this is reduced to 1.36atm by regulators on the pipe main to the combustion plant, where the gas pxessure may be further reduced to suit required combustion conditions and drying requirements. refining. Indirect Systems The indirect system can be applied in several ways, and with some types of dryer there is no alternative method of heat transfer to the product. The Through Conveyor Band Dryer can derive its hot air supply from a heat exchanger used in connection with an oil or coal-fired furnace. The heat exchanger comprises a set of cast iron or steel elements or plates, usually 33