Patent GB-1217248-A (GB)
Title: Improvements in or relating to crop-drying systems
IPC: F26B19/00
Filed: 1968-02-27
Abstract: 1,217,248. Mowing; haymaking. TEXAS INDUSTRIES Inc. 27 Feb., 1968 [17 March, 1967], No. 9506/68. Heading A1F. [Also in Divisions B8 and F4] Crops are dried in a superstructure mounted on a vehicle wherein two fans having outlets disposed at the same horizontal level, blow air into the superstructure. In a crop drier which is towed by a tractor, or the like, in the direction A when in use the drying chamber 10 made from sheet metal is mounted on a frame made from side pieces 1 and cross pieces (2), which also support the wheel bearings, wheels (7) and the fuel tank 71. The crop is picked up from the ground by a tined drum 19, supported by a wheel 21, in which the tines 18 move between scrapers 20 which remove entrained crop and deposit it between rollers 23, 27 which crush the crop to facilitate the drying process. The rollers 23, 27 are maintained in contact by a pivoted arm (25) and spring 29. After passing through the rollers, the crop is deposited on the lower part of the elevator channel 30. In a modification (Fig. 16, not shown), the crop is crushed between meshed rollers (144) and passed to a trough (145) at the lower end of the channel (30). Alternatively the crop may be cut by a flail mower (148) which avoids the use of crushing rollers, the crop being passed straight to the elevator channel (30) (Fig. 17, not shown). The crop is elevated by a number of rigid toothed supports 33 mounted on crankshafts 31, 32 at each end. The crankshafts are rotated such that the teeth 34 engage the crop as the supports 33 move upwardly and disengage as they move downwardly. The crank pins on which the supports are mounted are spaced at 120 degree intervals around the shafts 31, 32 and are more closely spaced along the shaft at the bottom than at the top. Thus as the crop is moved up the channel 30 it is spread out over the floor 14 of the channel. The floor 14 has perforations (36) which may be closed, by slides 37, operated by handles from one side, having corresponding perforations (38) (Fig. 4, not shown), to allow pre-heating of the crop by air passing up from the drying chamber 11. At the top of the elevator channel 30 the crop falls on to the first of a series of five conveyers 82-86. The first four conveyers 83-86 are formed from two horizontal perforated plates 91, 94 joined at their ends by curved plates 93 and also joined by partitions 96 which are inclined to the horizontal to ensure that air passes upwards through the conveyers to dry the crop. Each plate has a longitudinal central groove through which moves an endless chain (98). Secured to the chain are U-shaped bars 90 which move the crop over the plates 91. The conveyers run successively in opposite directions and when the crop reaches the end of one conveyer it drops down on to the one below. The lowermost conveyer 82 is similar to the others but runs over the floor of the chamber 11 and delivers the dried crop through the exit shoot (113). The conveyers are preferably driven by a ratchet and pawl mechanism which may be automatically controlled by a flap (133) (Fig. 13, not shown) which measures the depth of the crop layer on the conveyer 83 and which adjusts the amplitude of oscillation of the pawl arm thereby altering the speed of the conveyers (Fig. 15, not shown). The crop is dried by air blown through the chamber 11 by three fans situated between the feed elevator and the conveyers. Two fans 57 supply unheated air and are situated on the outer edges of the chamber. The third fan (67) is situated between the other two and blows air over a burner (69) into a combustion chamber 72 whose outlet 73 is between the outlets 60 of the other two fans 57. The burner is lit by a spark generated by the H.T. coil of an internal combustion engine (101) provided on the superstructure to drive the moving parts of the dryer (Fig. 5, not shown). Mounted above the outlets 60, 73 is an archimedean screw 77 which has one half right hand threaded and one half left hand threaded to mix the air issuing from the outlets 60, 73. Alternatively the outlet (118) from the heated fan may be enlarged (Fig. 12, not shown) and may have deflecting plates (119) fitted therein to mix the heated air with that issuing from the unheated fans (57) which may also have deflector plates (114). In a modification (Figs. 13-14, not shown), three heated fans having finned combustion chambers (122) are mounted behind two unheated fans (57) which draw in air issuing from the combustion chambers and also air which has been heated by contact therewith. After being blown into the chamber 11 the air is distributed therethrough by deflector plates which may be straight 43 or curved (123), Fig. 13, and are adjustable from outside the chamber 11. A flap 48, also externally adjustable, is provided to direct all the air delivered by the fans to the lower half of the chamber. The air flows along and through the conveyers and dries the crop. The rear wall of the chamber is closed by adjustable flaps (99) and plates (97) which may form a complete wall (Fig. 3, not shown). Distributed throughout the chamber are temperature gauges 106 which may be thermocouples (Fig. 9, not shown) or manometers (Fig. 10, not shown). The dials 109 for these are mounted on the exterior of the chamber such that the operator may adjust the air heaters, slides 37, flaps 43, rear flaps (99) in order to ensure the correct operating temperatures at various points.