Patent GB-861356-A (GB)
Title: Improvements in or relating to drying of agricultural and other products
IPC: F26B23/00
Filed: 1958-08-19
Abstract: 861,356. Drying grass and the like. CAPPS, A. W. F., and KNOX, J. R. Aug. 19, 1959 [Aug. 19, 1958], No. 26646/58. Class 34(2) In a grass &c. drying process suction is applied to a first compartment containing the grass and the vapour (and any air present) so obtained is compressed and delivered to a second compartment adjacent the first and separated therefrom by a flexible or displaceable wall. The drying apparatus comprises a horizontal cylindrical container 70, Fig. 5, disposed over a hopper 48 and having ends 54, a lid 68, Fig. 6, a longitudinal baffled feed pipe 44 and an internally located pipe 32 about which are rotatably mounted channel-sectioned rings 20a, Fig. 7, to each of which are .firmly secured by strings 86 a "stiff" flexible diaphragm 92 and a "baggy" flexible diaphragm 94 forming between them a "second" compartment. "First" compartments are formed within the container 70 between adjacent diaphragms 90, 94, of adjacent rings 20a. Each "second" compartment communicates with the interior of the pipe 32 through apertures 52 and is connected by tubes 100, Fig. 8, to a stationary pipe 102 connected to a suction pump and disposed within the pipe 32. A duct 60 which in operation connects with the suction side of a compressor 36 is formed in the lid which is hinged at 138 and is operated by an attached counterweighted lever 66. The pipe 32 open to atmosphere at one end and having a flow controlling valve 122, is connected by piping 116 to the discharge of the compressor 36 whilst the grass feed pipe 44 communicating with the hopper 48 incorporates a slide valve 126 mechanically connected to the valve 122. In operation the compressor draws air from the " first " compartments via the duct 60 and, as the valve 122 is closed whilst the valve 126 is open and the pipe 32 is open to atmosphere, grass is sucked into the compartments until they are full. The valve 122 is then opened, the valve 26 is closed and the exit to atmosphere from pipe 32 is blocked such that the initial air from the grass is compressed in the compressor and passed to the "second" compartments through the pipes 116 and 32 and the apertures 52. The "baggy" diaphragms 94 are thus extended transmitting pressure and heat to the grass in the "first" compartments to vaporize the moisture therein. This moisture is withdrawn by the compressor, compressed to vaporization and passed to the "second" compartments where after condensation it is withdrawn through the pipe 102 by the associated pump. To discharge the dried grass the lid 68 is raised and the rings 20a with associated diaphragms 90, 94 are swung outwardly as shown in Fig. 6. In a modified apparatus the grass may be agitated within the container 70 by providing cam means to rock the rings 20a about the pipe 32 and using an extendible hinge 138 to allow the lid 68 to move to accommodate the rocking rings. In order to facilitate charging by preventing the lodgement of grass the baffled feed pipe 44 may have controlled air inlets such that during charging air is induced therein in tangential whirls.