RU2134952C1 - Apparatus for drying bulk granular materials - Google Patents

Abstract

FIELD: agriculture. SUBSTANCE: apparatus has housing with charging and discharge device, drying chamber, suction branch pipe, air supplying chamber and airduct connected to air supplying chamber. Heating members mounted in drying chamber have set of U-shaped plates made in the form of troughs which are divided by ribs into sections connected to power source and defining gas distributing grid. Material to be treated is fed from feeder into drying chamber and while moving across heating chamber it is subjected to contact-convective heating, with penetrating air heat flux being convectively supplied. Heat flux intensively absorbs moisture from material under treatment and material is further fed to discharge device. EFFECT: simplified construction, enhanced reliability in operation, intensified drying process. 2 dwg

Description

 The invention relates to a technique for drying bulk granular materials using electrical energy and can be used in the field of agriculture for drying grain.

 A device for heat treatment of dispersed materials, containing a device for loading and unloading material, a vibrating gas distribution grid connected by a hermetically flexible insert with a gas supply chamber, in which there are suction valves and air heater [1].

 The disadvantage of this device is its high energy consumption, since part of the heat flux obtained from the air heater is lost on heating the walls of the gas supply chamber. The device is complex in design, since a vibro-exciter is needed to create vibrations of the vibrating gas distribution grill. In addition, this device does not exclude the possibility of dispersed material entering through the openings of the gas distribution grill into the suction valves of the gas supply chamber, which can jam the latter and cause them to fail, which reduces operational reliability.

 In the case of an embodiment of the device with a gas distribution grid in the form of separate connected heating elements of a triangular shape, convective and conductive heat treatment is provided, but heating elements of this shape form only channels for the heat carrier to pass under the layer of the processed material and do not create a directed air heat flow to the material to be dried, which would have a transporting effect and at the same time ensure its active mixing, and this reduces the intensity vnost heat treatment.

 The closest in technical essence and the achieved result to the proposed technical solution is the installation for drying granular materials in a fluidized bed, containing a housing, a gas distribution section grate, between the sections of which are installed heating elements made in the form of vertical longitudinal ribs and connected, as well as sections of the gas distribution grate to the current source [2].

 However, in this installation, heating elements made in the form of vertical longitudinal ribs, when immersed in a grain layer, do not provide a convective supply to the processed material of an air heat flow that has a conveying effect, since they are not washed by the coolant, but only conductive heating is carried out, which reduces drying intensity.

 In the case of an embodiment of a device in the form of a rectangular tray used in multi-tray dryers with a vibro-boiling layer, active mixing of the processed material will be achieved mainly due to vibration exposure, but the operation of heating elements under vibration leads to the destruction of current-carrying contact joints, which reduces operational reliability.

 In addition, in installations with a vibro-boiling layer, active mixing of the processed material occurs only in the layer bordering on the vibrating surface, and in more distant layers, under the action of vibrations, the material is densified and stagnant zones are formed, which reduces the drying intensity.

 The invention is aimed at improving the operational reliability and intensification of the drying process by creating a supply of penetrating conveying air heat flow from the heating elements to the processed material.

 The task is achieved in that the heating elements are made in the form of sets of U-shaped plates having the shape of gutters, separated by insulating ribs into sections connected to a current source, and form a gas distribution grid, while the plates of the heating elements are installed in a row with overlapping, horizontal displacement and a longitudinal slotted gap relative to each other and connected in series by electrical connection.

 In FIG. 1 shows a installation for drying bulk granular materials, a longitudinal section; in FIG. 2 is a section AA in FIG. 1.

 The installation comprises a housing 1, including a loading 2 and an unloading 3 device, a drying chamber 4, an exhaust pipe 5, an air supply chamber 6, to which a fan duct 7 (not shown) is connected. In the drying chamber 4, heating elements 8 are installed, made in the form of sets of U-shaped plates 9 having the shape of grooves, longitudinally separated by insulating ribs 10 into sections, and forming a gas distribution grid.

 The plates 9 are installed in a row with overlapping, horizontal displacement and a longitudinal slot gap relative to each other and are connected at the ends at the edges, while the connections of some edges are made through conductive inserts 11, and others through insulating inserts 12. Conducting 11 and insulating 12 inserts are installed in a series with alternating between themselves and form a serial electrical connection between the plates 9, the end of which have conclusions 13 and 14 in the junction boxes 15 and 16.

 The front wall 17 of the drying chamber 4 and the rear wall 18 of the air supply chamber 6, made of heat-resistant dielectric material, isolate heating elements 8 from the housing 1, connected to the current source by flexible wires 19 in the outer 15 and inner 16 junction boxes. The side walls of the drying chamber 4 are isolated from the heating elements 8 through insulating spacers installed between them 20. The insulating ribs 10, fixed at the ends in the front wall 17 of the drying chamber 4 and the rear wall 18 of the air supply chamber 6, isolate the heating elements 8 and support them from deflection.

 For portioned unloading of the installation, the unloading device 3 has a valve 21 with a load of 22, and to prevent the material being processed into the air duct 7, shutters 23 are installed on the front wall 17 of the drying chamber 4.

 Installation works as follows.

 Wet material through the loading device 2 enters the drying chamber 4, while the heating elements 8 are connected using flexible wires 19 to a current source and through the duct 7 and the air supply chamber 6 serves transporting air. Air passing under pressure through the plates 9 and washing them is heated and fluidizes the dried material with a uniform heat flow, providing its directed movement from the loading device 2 to the unloading device 3. The fluidized material moving along the heating elements 8 is subjected to contact-conductive heating with simultaneous convective supply of a penetrating air heat flow, while the dried material intensively gives moisture to the latter.

 The spent coolant exits through the pipe 5 and partially with the dried material through the unloading device 3.

 Most preferred is the embodiment of the installation with the heating elements 8 tilted in the direction of the dried material to the discharge device 3. This improves the flow conditions of the fluidized material and eliminates the possibility of grain entering through the gaps between the heating plates 9 into the air supply chamber 6.

 The proposed installation differs from the known one in that the heating elements in it create contact-conductive heating of the processed material with the simultaneous convective supply of a piercing conveying air heat flow, which ensures the movement of the dried material from the loading device to the unloading device. Thus, the invention improves the operational reliability of the installation and intensifies the drying process.

Sources of information
1. Copyright certificate of the USSR 613182, cl. F 26 V 17/10, 06/25/78
2. Copyright certificate of the USSR 779769, cl. F 26 B 17/26, 3/34, 11/15/80.

Claims (1)

 Installation for drying bulk granular materials, comprising a housing, a gas distribution grill located inside the housing, heating elements connected to a current source, devices for loading and unloading the processed material, supply and output of a drying agent, characterized in that the gas distribution grill is made in the form of U-shaped sets plates interconnected by lateral faces by means of ribs made of dielectric material, with plates sequentially installed along the axis k rpusa partially overlap each other and form the slit clearance with respect to each other, are connected in an electrical circuit.

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