TH71124A - Air-Driven Duct Dryer - Google Patents

Abstract

DC60 (01/04/48) This patented patent describes a novel method for drying paddy rice using a tubular air dehumidifier. Unlike conventional methods, this new design allows for rapid moisture reduction without damaging the rice grains. Air from a fan moves through a channel containing hot combustion gases, increasing its temperature. This hot air is then forced at high speed, convectively moving the paddy rice along the length of the air duct. After exiting the hot air duct, a cyclone separates the paddy rice from dust particles. This heat transfer results in a significant reduction in paddy rice moisture content in a short time. Air from the fan moves through the flow channel of hot gases generated by combustion, causing the air to heat up. The hot air is then forced to move at high speed, carrying the rice grains in the same direction along the length of the air duct. Once the rice grains exit the hot air duct, a cyclone separates them from the dust particles. This heat transfer significantly reduces the moisture content of the rice grains in a short period of time.

Claims (4)

The tube-assisted air dryer consists of a centrifugal fan that creates a steep air pressure, forcing the air along the length of the tube. It starts with a horizontal hot air tube (8) and draws heat from the combustion chamber (21), increasing the air's temperature as it passes through a vertical hot air tube (35) (upward direction). Paddy rice, conveyed from screw conveyors (44 and 47), flows and mixes with the air in the same direction, causing heat and mass transfer between the rice and hot air, thus reducing its moisture content. The rice and hot air then move through a vertical hot air tube (61) (downward direction) and enter a cyclone before being separated. This type of dryer was designed to reduce the moisture content of paddy rice and has specific characteristics. 1. Pipe arrangement: The dryer's pipes are arranged in vertical upward and downward directions, forcing the hot air and paddy grains to mix well in a short period of time. 2. Installing a cyclone at the outlet: Since the rice grains move with high-speed hot air, installing a cyclone at the outlet will reduce the speed of the rice grains before they exit. It also helps to separate out dust and other particles carried with the rice grains. 3. Installation of the paddy conveyor system: The conveying system is designed to be installed behind the heat generator. As the paddy is conveyed down the pipe, the high-temperature pressure force the paddy to flow rapidly upwards, simultaneously reducing its moisture content. 4. Burner and Combustion Chamber Installation: The gas burner is installed inside the combustion chamber, with the gas passages located outside. The combustion chamber is situated between the centrifugal fan and the lower hot air bend, slightly away from the fan.