GB677906A - Improvements in or relating to apparatus for drying or dehydrating vegetable substances - Google Patents

Abstract

677,906. Drying apparatus. DOLBY, G. R. A. Nov. 3, 1950 [Aug. 8, 1949], No. 20561/49. Class 34(ii) Apparatus for drying vegetable crops comprises a rotary drying drum 10 the wall of which is exposed to the atmosphere having a plurality of ventilators 37 fitted along the wall so that they can be individually turned to face the air resistance to admit air into the drum or turned in the opposite direction to discharge moisture laden air from the drum. The drum 10 has annular guide tracks 15' which engage rollers 16<SP>1</SP> mounted on spindles 17' bearing in brackets 18' secured to a wheeled carriage 11. The drum is lagged and closed by an end plate apertured to receive a cylinder 27 in which is mounted a combustion chamber 20 leaving an annular space 21 for the passage of air, the output end 22 of the drum being open but partly covered at the top by a hood 23. Chamber 20 has its opening into the drum partly, obstructed by a circular baffle 24 supported by plates 25, 25<SP>1</SP>, the rear ends of cylinder 27 and tube 20 being closed by a plate 32 curved at its lower end to form with a reversed wall 33 of cylinder 27 a passage for forced draught produced by a fan 28 driven by power unit 31 mounted in a space 29 behind the plate 32 where is also mounted an oil burner 30. Material fed into a casing 40 enclosing the cylinder 27 is carried around the outside of cylinder 20 into and through the drum, the amount of outside air admitted to the drum and of moisture laden air withdrawn being regulated by turning one or more of the ventilators 37 in a suitable direction.