RU203873U1 - DRYING CHAMBER FOR BULK MATERIALS - Google Patents

Abstract

The utility model relates to mechanical engineering, in particular to devices for drying (removing moisture) from loose and lumpy materials: sawdust, chips, grain, crushed grass, with an input moisture content of 50-70%, an output of 10-12%, and can be used for the production of fuel pellets, feed, fertilizers. The drying chamber for bulk materials contains a housing made with the possibility of being connected to a feed conveyor and a heat generator, having a channel for the supply of raw materials and an outlet channel, the lower part of the housing includes horizontally oriented semi-cylinders open from above, inside which there are independent shafts with blades installed along the entire length on the rods. Each half-cylinder of the drying chamber is made smooth over the entire surface of a solid sheet, the half-cylinders are installed in such a way that the inner edges have an interval between themselves, forming an opening, a divider is installed above the opening between the half-cylinders above the inner edges, made in the form of a horizontally oriented box made of a gull-shaped profile convex surfaces upwards and two flat sheets converging at an angle above them, forming a pointed cover, the divider is fixed to the transverse figured plates protruding with an acute triangle above the half-cylinders, perpendicular to their longitudinal axis. The technical result is an increase in productivity due to a decrease in the internal hydraulic resistance for the passage of heated air. 2 ill.

Description

The utility model relates to mechanical engineering, in particular to devices for drying (removing moisture) from loose and lumpy materials: sawdust, chips, grain, crushed grass, cake, beer stillage with an input moisture content of 50-70%, an output of 10-12%, and can be used for the production of fuel pellets, feed, fertilizers.

Known technical solution for the patent SU No. 1191704 A, F26B 11/14, 17/20 from 26.06.1984, published on 15.11.1985, according to which a rotary dryer (for drying dispersed materials) containing a chamber with a working and separation zones, rotors installed in the lower part of the working area, and a gas distribution box for introducing the coolant along the entire length of the chamber, at the opposite ends of which there are loading and unloading nozzles, characterized in that in order to increase productivity and reduce energy consumption, the working and separation zones are separated by a longitudinal partition, and the box is installed in the upper part of the working area and is connected to it by means of a grid with a variable free cross-section, decreasing towards the unloading branch pipe, and the working area is additionally divided into sections by transverse partitions.

However, the analysis of the known design revealed the following disadvantages. The purpose of the design is indicated "for drying dispersed materials with forced mixing in a suspended bed", from which it follows that the rotor requires high speed to toss up the material to be dried. As a result, precision in the manufacture of shafts with blades and their balancing is required, the complexity of machining in a lathe is the entire length of the shaft. In addition, when trying to dry raw sawdust, or chips in this design, the problem of clogging of the damper will inevitably arise. Having passed the narrow part near the damper, small wet particles will enter the expansion zone, where the speed decreases, while the wet particles of the material, settling on the walls, will build up and close the passage. Thus, it is impossible to reverse when drying sawdust, wood chips, grain, crushed grass, cake, since the raw particles lifted by the rotors will fall into the grate windows and clog it and the box in the working chamber, while separation is excluded.

The analogue has one rotor shaft in the longitudinal axis, which limits the performance of the dryer. In addition, the scheme for feeding the hot reagent from top to bottom is less effective than in the inventive dryer from the bottom to the top, when the hot drying reagent, heating the half-cylinders, enters the opening between the cylinders, and then into the cylinder cavity, following the laws of physics, heats the material falling on it more efficiently ... There are no known examples of the use of a rotary dryer of this design for drying sawdust, wood chips, grain, crushed grass, cake from the existing prior art.

The closest to the claimed one is the technical solution according to the patent RU No. 187934 U1, F26В 11/14, 17/20 dated 09/04/2018, published: 03/25/2019, according to which the drying chamber for bulk materials contains in the lower part of the housing horizontally oriented half-cylinders, open at the top, inside the half-cylinders there are independent shafts, on which blades are mounted on rods along the entire length, with each rod located perpendicular to the axis of the shaft, and the blade is made in the form of a rectangular plate with rotation around the axis of the rod in such a way that it forms a sharp angle with respect to the longitudinal axis of the shaft. Each shaft is equipped with its own shaft-mounted gearbox (which has its own rotational speed) with the possibility of rotation of the shafts closest to the raw material loading window at a higher speed than the subsequent ones. The upper part of the body is made in the form of a rectangular cover with a bevel (truncated part) and has an opening with an air-swirling volute. A cyclone is installed in the horizontal plane of the truncated part of the housing cover, which is connected hermetically to the volute and through a sluice gate hermetically connected to the internal cavity of the device. Each of the shafts has an exit from the end of the device through a seal in the housing, for fastening the gearboxes, the inner ends of the shafts are freely fixed in the supporting support, each in its own bearing. At the end of the body on one side there are holes (windows) for feeding material sequentially through the throat, sluice gate, channel into each section of the drying chamber. Each half-cylinder of the drying chamber has windows - nozzles, the purpose of which is to increase the efficiency of heat exchange, for which the heated air meets the material throughout the entire inner cavity, blowing through the numerous nozzle windows along the entire length of each half-cylinder. In addition, an air duct is organized between the half-cylinders for supplying hot air to the windows - nozzles and through them into the half-cylinders.However, in practice, the prototype design revealed a significant drawback: heated air does not pass quickly enough through narrow nozzle windows, which have high hydraulic resistance, which significantly reduces the volume and the speed of the air flow, as a result, the performance of the drying chamber is significantly reduced.

To eliminate this drawback, the following changes are proposed: nozzle windows in the surface of half-cylinders are excluded from the design of the prototype, as an element that is difficult to manufacture, creating significant hydraulic resistance, which reduces the volume and air flow rate by 30% (determined by calculations and practical measurements), respectively. the absence increases the heat exchange performance of the new design of the drying chamber with smooth surfaces of the semi-cylinders by 30%. To increase the heat exchange performance in the inventive design, a space for hot air is provided between the half-cylinders - that is, the half-cylinders do not come into contact with the inner side edges of each other as in the prototype, but are installed with an interval through which hot air freely passes upward. In this case, the inner edges of the semi-cylinders are higher than the outer ones. The heated air from the duct flows upward through the opening between the half-cylinders, above which the air flow divider is installed. The divider is made in the form of a horizontally oriented longitudinal part, for example, in the form of a box made of a gull-shaped profile with convex surfaces upward and two flat sheets converging at an angle above them, forming a sharp cover that serves to prevent dust accumulation during device operation.

The splitter is fixed to the transverse figured plates, protruding an acute triangle above the half-cylinders, perpendicular to their longitudinal axis. The flow of heated air from the duct rises up into the opening between the half-cylinders and is divided by the sharp edge of the gull-shaped profile of the divider, then it is directed to the left and right half-cylinder. By dividing the air flow, the diffuser directs the heated air into each half-cylinder, which doubles the flow area of the air flow compared to the nozzles. With an increase in the volume and speed of the heated air flow, the productivity increased by 30%.

Technical task: to increase the productivity of the drying chamber by reducing the internal hydraulic resistance.

To solve this problem, a drying chamber is proposed for drying bulk and lumpy materials with several shafts, for example, a four-shaft one. The structure includes a body, the lower part of which consists, for example, of two horizontally oriented steel half-cylinders, open at the top, having the shape of a straight circular cylinder, cut by an axial section horizontally and installed in parallel with an interval along the longitudinal edge. In the space formed between the diameters of the half-cylinders, the channel is supplied with heated clean air, which, rising up and being directed by the divider into both half-cylinders, blows the drying material (raw material).

The upper part of the body, common to the half-cylinders, is similar to the design of the prototype: predominantly rectangular, made of steel plates, truncated on one end side at an angle and covers the half-cylinders like a cover, moist air is collected in it, its height H is always greater than the radius of the half-cylinders R. In each of two steel half-cylinders along the longitudinal axis, two independent shafts are arranged in series one after the other, on which the blades are attached. The shaft is equipped with rods mounted perpendicular to the longitudinal axis of the shaft, on which blades are installed in the form of rectangular plates with rotation around the axis of the rod in such a way that the surface of the blade forms an acute angle with respect to the longitudinal axis of the shaft. In this type, the shaft with blades is a type of shaped screw, which mixes the material in a half-cylinder and simultaneously moves it from the inlet to the outlet. Each of the four shafts is driven by its own shaft-mounted gearbox, and has its own speed in pairs, the first two (closest to the raw material loading holes) rotate faster than the next two. In the upper part of the body there is an opening with an air-swirling volute. A cyclone is installed in the horizontal plane of the truncated part, which is connected hermetically to the volute and through a sluice gate, which is hermetically connected to the internal cavity of the device. Each of the four shafts has one exit from the end of the housing through a seal for mounting gearboxes, the inner ends of the shafts are freely fixed in an intermediate support, each in its own bearing. At the end of the body, on one side, there are openings into which material (raw material) for drying is fed through the neck, sluice gate, channel, into each section of the drying chamber. On the other hand, in the lower part of the half-cylinders, there are openings for unloading material through the airlock.

Unlike the prototype, the steel half-cylinders are smooth, without holes (nozzles) along the entire length, installed with an interval between the inner edges, and form an opening for hot air to pass into the upper part of the drying chamber. In this case, the inner edges are higher than the outer ones. Above the opening between the semi-cylinders, above the inner edges, a divider is installed, made in the form of a horizontally oriented box of a gull-shaped profile with convex surfaces upward and two flat sheets converging at an angle above them, forming a sharp cover, to prevent dust accumulation during device operation.

The splitter is fixed to the transverse figured plates, protruding an acute triangle above the half-cylinders, perpendicular to their longitudinal axis. When the drying chamber is operating, the heated air flow from the duct rises up and is divided by the sharp edge of the gull-shaped divider box, being directed to the left and right half-cylinders for blowing and drying raw materials, which doubles the flow area of the air flow in comparison with nozzles. The heated air is directed inside each half-cylinder with the help of a divider, its volume is larger than that of the prototype, and with an increase in the volume of the heated air flow, the drying chamber performance increased by 30%.

A cyclone with a fan creating a vacuum is installed on the top of the body, with the possibility of removing the wet drying reagent from the cavity of the dryer, settling fine dust and returning it back to the raw material flow through the sluice gate. The side surface of the body is equipped with a door for servicing the internal cavity, removing and installing shafts.

The technical result is an increase in productivity due to a decrease in the internal hydraulic resistance of passages for heated air.

The technical result is achieved due to the design of the drying chamber, containing a housing made with the possibility of being connected to a feed conveyor and a heat generator, having a channel for the supply of raw materials and an output channel, while the lower part of the housing includes horizontally oriented half-cylinders open from above, inside which there are independent shafts with mounted on the entire length on the rods with blades, characterized in that each half-cylinder of the drying chamber is made smooth over the entire surface of a solid sheet, the half-cylinders are installed in such a way that the inner edges have an interval between themselves, forming an opening, while the inner edges end above the outer ones, above the opening between half-cylinders above the inner edges installed a divider made in the form of a horizontally oriented box made of a gull-shaped profile with convex surfaces upward and two flat sheets converging at an angle above them, forming a pointed cover, the divider is fixed n to the transverse figured plates, protruding an acute triangle above the half-cylinders, perpendicular to their longitudinal axis.

Differences from the prototype

1. In the design of the prototype, air passes through the nozzle windows, which have high hydraulic resistance, which reduces the volume and speed of the air flow, as a result, low productivity. To increase the efficiency of heat exchange in the proposed model, the half-cylinders are installed with an interval for the passage of hot air from the duct through the opening, then the flow divider into the half-cylinder, which doubled the flow area in relation to the nozzles. With an increase in the volume and speed of passing air, the productivity increased by 30%.

2. Thus, nozzle windows are excluded from the design of the drying chamber of the prototype, as a difficult to manufacture element that creates significant hydraulic resistance, which reduces the volume of air flow by 30% (determined by calculations), respectively, the heat transfer performance in the new design improves by 30% ...

3. Hot air from the heat generator under pressure enters the air duct, which runs along the entire length of the drying chamber and creates excess pressure in it. In the design of the prototype, air under pressure was blown out of the air duct through small nozzle windows into the half-cylinders (this was necessary to prevent small sawdust from entering the inner cavity of the air duct, since the nozzle windows were located very low), while the volume and speed of air circulation was lost.

In the claimed design, the air outlet in the cavity of the semi-cylinders is high, for its passage along the entire length, the window is several times larger than the sum of the cross-sections of the nozzle windows. Having fewer obstacles in its path, the volume and speed of the flow of the warm air mass increases, the rate of heat exchange and drying performance increase, in the same volume of the drying chamber.

4. In the claimed technical solution, hot air passes through the opening between the semi-cylinders to the top of the chamber, then, with the help of a divider, it enters the semi-cylinders and heats them inside the housing, which contributes to the drying process of the material constantly in them, while saving heat, the semi-cylinders form on both sides air distribution duct, which increases productivity and reduces energy consumption.

The essence of the technical solution is illustrated by the images in FIG. 12.

FIG. 1 is a diagram of the operation of the drying chamber from the end in section.

FIG. 2 - isometric view of the drying chamber (lower part),

where 1 is the direction of movement of the heated air,

2 - air duct,

3 - gull-shaped profile of the divider,

4 - divider cover,

5 - figured plates protruding with an acute triangle above the half-cylinders, perpendicular to their longitudinal axis.

6 - divider, as a prefabricated part,

7 - half-cylinder,

8 - case,

9 - blades.

An example of implementation.

The structure contains a housing 8, the lower part of which includes two (for example) steel half-cylinders 7, fixed with an interval between the inner edges in a row parallel along the longitudinal edges with the rounded part downward. In the space of the air duct 2 formed between the diameters of the half-cylinders, heated clean air 1 is supplied, which passes upward, is divided by the divider 6 into two streams, each of which then enters its own half-cylinder 7 and blows the drying material (raw material). Above the opening between the semi-cylinders above the inner edges, a divider 6 is installed, made in the form of a horizontally oriented box made of a gull-shaped profile 3 with convex surfaces upward and two flat sheets 4 converging at an angle above them, forming a pointed cover 4. The divider 6 is fixed to the transverse figured plates 5 , a protruding acute triangle above the semi-cylinders 7, perpendicular to their longitudinal axis.

The upper part of the body 8 is common for all semi-cylinders, predominantly rectangular, made of plates (steel sheets), truncated at one end side at an angle and covers the semi-cylinders 7 like a cover. It collects humid air, its height H is always greater than the radius of the half-cylinders R. In each of the two steel half-cylinders 7 along the axis of symmetry, two independent shafts are sequentially located along one after the other, on which the blades 9 are attached to the rods. The blades 9 are arranged with a turn around its axis, coinciding with the axis of the rod in such a way that they form an acute angle (for example, 7-15 °) with respect to the longitudinal axis of the shaft and represent with the shaft a kind of shaped screw of large diameter, with the help of which the material is agitated and moves from the loading hole to the hole unloading, along the half-cylinders 7. Each of the shafts is driven by its mounted gearbox, and in pairs has its own frequency of rotation, the two shafts closest to the loading of the raw material rotate faster than the next two. In the upper part of the body 8 there is an opening with an air-swirling volute. A cyclone is installed in the horizontal plane of the truncated part, which is connected hermetically to the volute and through a sluice gate, which is hermetically connected to the internal cavity of the device. Each of the four shafts has one exit from the end of the device, through a seal in the housing, for attaching gearboxes, the inner ends of the shafts are freely fixed in an intermediate, supporting support, each in its own bearing. At the end of the body, on one side, there are openings into which through the neck, sluice gate, channel, material for drying is fed into each section of the drying chamber. On the other hand, in the lower part of the half-cylinders 7, there are openings for discharging material through the sluice gates.

The device works as follows.

The wet raw material enters through the inlet funnel, the sluice gate, the raw material inlet channel, into the half-cylinders 7, then by the blades 9, is mixed, dried and moves to the unloading hole, goes out through the sluice gate, then it is pneumatically transported to the storage hopper (not shown). The blades 9 lift the raw material up, at the top point the raw material falls down, is actively blown with hot air, gives off moisture, dries. From the moment it enters the cavity of the semi-cylinder 7, the raw material falls under the air flow of hot air 1.

The source of hot air is, for example, a double-circuit heat generator operating on gas, wood chips, sawdust, fuel oil with a temperature of up to 150 °. Hot air is supplied to channel 2 of the dryer by means of air ducts. To move air in the drying chamber itself, a cyclone fan creates a vacuum, since it is hermetically connected through the snail to the inner sealed cavity of the drying chamber, and a vacuum occurs in it. The stream of heated air 1, rising upward, falls on the splitter 6 and is divided into two streams by a gull-shaped profile 3, each of which, falling into its own half-cylinder on the falling raw material, intensively dries it.

Hot air from the heat generator under pressure enters the air duct 2, which runs along the entire length of the drying chamber and creates excess pressure in it. In the claimed design, in contrast to the prototype, the air outlet in the cavity of the semi-cylinders 7 is located high, for its passage along the entire length, the window is several times larger in cross-section than the sum of the cross-sections of the nozzle windows. With fewer obstacles in its path, the volume and flow rate of the warm air mass increases, the rate of heat exchange and drying performance in the same volume of the drying chamber increase. Productivity is increased, without additional increase in the cost of the structure, only due to the changes introduced. In addition, the technological process of the nozzle windows is laborious, and the claimed design is simpler and more efficient.

Claims (1)

Drying chamber for bulk materials, containing a housing made with the possibility of being connected to a feed conveyor and a heat generator, having a channel for the supply of raw materials and an outlet channel, while the lower part of the housing includes horizontally oriented half-cylinders open from above, inside which there are independent shafts with installed along the entire length on rods with blades, characterized in that each half-cylinder of the drying chamber is made smooth over the entire surface of a solid sheet, the half-cylinders are installed in such a way that the inner edges have an interval between themselves, forming an opening, while the inner edges end above the outer ones, above the opening between the half-cylinders above the inner ones of the edges, a divider is installed, made in the form of a horizontally oriented box made of a gull-shaped profile with convex surfaces upward and two flat sheets converging at an angle above them, forming a pointed cover, the divider is fixed to the transverse figured plates am, protruding an acute triangle above the half-cylinders, perpendicular to their longitudinal axis.

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