RU2176059C2 - Multizone continuous-belt drier for drying of loose and poorly loose materials - Google Patents

Abstract

FIELD: agricultural machine building, particularly, machines for drying of loose granular materials, more specifically, cereal crops and poorly loose materials such as flaxseed thrashed heaps. SUBSTANCE: drying is carried out by formation of periodically operating zones of heating, resting and cooling on sections of drying agent transversely directed to periodically moved material in direction of transportation by means of installation above working branch of conveyer 9 of alternating pressure and suction boxes 21, 22, 12 and 7, 19 whose bottom bases have inclined plates 3, 8 ensuring reverse motion of drying agent through drying chamber. Installed under working branch of conveyer 9 alternately are suction and pressure boxes provided with perforated bottoms. 13. Said boxes ensure motion of drying agent in vertical direction. EFFECT: higher reliability of drying cereal crops and poorly loose agricultural materials.

Description

 The invention relates to agricultural machinery, specifically to machines for drying bulk granular materials, in particular grains of cereal crops and low-flowing materials, such as flaxseed.

 A tunnel dryer for drying bulk materials is known, comprising rack-mounted racks with mesh bases in belts arranged in a tunnel for placing the material to be dried, forming horizontal channels connected to vertical distributing and collecting manifolds for supplying and discharging a drying agent, and heat and ventilation equipment. However, it is characterized by inefficient use of the heat of the drying agent, since the absence of a recirculation loop does not allow to reduce the energy intensity of the drying process [1].

 A known dryer with an intermediate loading of loose-flowing material, including a drying chamber, loading and distribution conveyors, a gas supply duct with a gas distribution grill, on the surface of which there is a conveyor having slats with vertical teeth and rods periodically inserted into the drying chamber. The conveyor removes the bottom layer of dried material from the dryer. However, the drying agent is blown once through a layer of the dried material, which does not provide high efficiency and cost-effectiveness of drying [2].

 Known dryer with intermediate heating and recirculation of the drying agent. The dryer contains discharge and suction ducts, nozzles with throttles, a drying chamber, inside which two trolleys with racks are installed, on which the dried material is placed. The direction of passage of the drying agent through the drying chamber is set by the blank surface of the shelves and the distribution peaks. However, this design due to the presence of leaks between the suction, discharge nozzles and racks of the trolley, and also because of the inability to precisely match the drying zones of the first and second trolleys in height, leads to the formation of stagnant zones and uneven drying of the material, which does not provide high efficiency and drying economics [3, p. 67].

 Closest to the claimed technical essence and the achieved result is a multi-zone dryer for drying fibrous materials. A multi-zone dryer contains a drying chamber with a conveyor, loading and unloading devices, pressure boxes with movable air guide screens. A casing is installed above the working branch of the conveyor, the ceiling part of which is made in the form of a profiled lattice [4]. The multi-zone dryer is characterized in that it provides uniform drying of the layer of flax trusts across the width of the conveyor. However, in installations with the supply of the drying agent only from the top of the material layer or from the lower boundary of the entire layer to be dried, the difference in humidity of the lower and upper layers can reach from 3 to 29% with an initial moisture content of flax seeds 28 .... 30%.

 The present invention is aimed at improving the reliability and intensification of the drying process of bulk and low-flowing agricultural materials.

 The problem is solved in that over the working branch of the conveyor, discharge and suction boxes are installed alternately, the lower bases of which are equipped with inclined plates that provide periodic reverse movement of the drying agent through the drying chamber, and under the working branch of the conveyor, suction and discharge boxes are equipped with a perforated bottom, which carry out the movement of the drying agent in the vertical direction. This achieves the creation of periodically working zones of heating, "curing" and cooling in areas of the transversely directed drying agent to the periodically moved material in the direction of transportation.

 The proposed design of a conveyor multi-zone dryer due to the distinguishing features provides a solution to the problem of increasing the efficiency and profitability of drying.

 In FIG. 1 schematically shows the proposed conveyor multi-zone dryer - a longitudinal section; in FIG. 2 - same, plan view.

 A multi-zone conveyor dryer for drying bulk and low-flowing materials contains pressure channels 2.5 and 18 with pressure boxes 21, 22 and 12, suction boxes 7 and 19, a recirculation loop including a pipe 24 with a fan 23, a fan 17 connected by a pipe 16 to a cyclone (cyclone not shown). Boxes 21 and 22, mounted above the drying chamber 20, in the lower base are provided with guides (deflecting) of the drying agent 3 against the movement of the material, and the box 7 is equipped with plates 8 installed at an angle along the direction of the dried material. The bottom 13 of the drying chamber 20 has a perforation, the exit slots of which are oriented along the direction of movement of the material. Above the bottom 13, the upper branch of the chain-slat conveyor 9 passes, the teeth are fixed to the conveyor straps 10. The heat generator 26 is connected to the discharge channels 2 and 18 by means of a dividing pipe 25 with a valve 1, and a suction box is provided in the box 7 from the outlet side of the material from the drying chamber movable dividing wall 6. Loading and unloading devices are not shown.

 The multi-zone conveyor dryer works as follows: material, for example flaxseed or grain, is laid in layers on the perforated bottom 13 and the slats with teeth 10 of the conveyor 9 are moved along the drying chamber 20 at a given speed. After filling the drying chamber with material, the heat generator 26 and fans 23 and 17 are turned on. The drying agent through the discharge channel 2 and the duct 21 enters the layers of material, penetrating them from top to bottom, and the discharge channel 18 and the duct 12, the drying agent is fed into the layers of material from the bottom up. In the zone 4 of the drying chamber, the drying agent moves from top to bottom, the material in the upper layers is loosened by the directed flows of the drying agent by the plates 3 of the box 21. In this case, the drying agent intensively heats the upper layers of the dried material and penetrates the lower layers during operation of the fan 17. This ensures evaporation of moisture from the surface material and its gradual heating. The used drying agent in this zone, passing through the layers of material, is sent by the fan 17 through the pipeline 16 to the cyclone, and from the cyclone to the heat exchanger of the heat generator 26.

 In the zone 14 of the purge of material from the bottom up, the drying agent is fed through the discharge channel 18 and the duct 12 into the preheated and dried material. As a result, uniformity of drying of the material is ensured both in width and in layer height. Moreover, due to the presence of a recirculation circuit (which includes a fan 23, pipe 24, etc.), the dried material in zone 15 is additionally exposed to the flows of the drying agent, pumped from top to bottom. The drying agent, passing through the layers of material, in a section of this zone by a fan 17 is sent through a pipeline 16 to a cyclone.

 In the cooling zone 11, the layers of material are penetrated by the external air from the bottom up, the cooling intensity and the amount of atmospheric air drawn in by the fan 23 are set by a movable dividing partition 6, which is very useful for additional moisture removal up to 0.5 .... 1.0%.

 Due to the design features of a multi-zone conveyor dryer, the heat consumption for drying the material is significantly reduced, the moisture uniformity of the dried layers of the material is increased, and, most importantly, the maximum return of the driving forces of the drying process is ensured with minimal energy costs.

Sources of information
1. Copyright certificate of the USSR 540114, cl. F 26 B 15/14.

 2. Copyright certificate of the USSR 375457, cl. F 26 B 17/04.

 3. Lebedev P.D. Calculation and design of drying plants. - M.: Gosenergoizdat, 1963 .-- 320 p., Ill.

 4. Copyright certificate of the USSR 553421, cl. F 26 B 17/04.

Claims (2)

 1. Conveyor multi-zone dryer for drying bulk and low-flowing materials, containing a drying chamber with a conveyor, loading and unloading devices, pressure boxes, characterized in that over the working branch of the conveyor are installed alternately discharge and suction boxes, the lower bases of which are equipped with inclined plates, providing periodic reverse movement of the drying agent through the drying chamber, and under the working branch of the conveyor, suction and discharge boxes are alternately installed, bzhennye perforated bottom, through which the motion of the agent in the vertical direction of drying.  2. The conveyor multi-zone dryer according to claim 1, characterized in that on the outlet side of the material from the drying chamber, the suction box is equipped with a movable dividing wall.

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