RU2753785C1 - Method for distributing gas in a louver-type shaft grain dryer and apparatus for implementation thereof - Google Patents

Abstract

FIELD: drying.

SUBSTANCE: invention relates to drying equipment and can be used in agricultural and other grain dryers with a gravitational moving layer, e.g., louver, column, etc. A method and apparatus for distributing gas in a louver-type shaft grain dryer consisting of a heated air chamber, a moist air chamber, a drying and cooling vertical chamber from modules installed one above the other forming a shaft, several narrow shafts are located in each module, with louvers located thereon from top to bottom in several rows, separated from each other and from the walls of the module by supply and discharge channels. According to the invention, the gas supplied to the supply channels near each louver is divided into three flows, wherein one of the flows passes through the under-louver slits, the second one - through the "shark gills"-type louvers located on the vertical sides of the louvers, and the third one - through the "shark gills"-type louvers located on the bent side of the louvers, wherein all three gas flows pass through the louver column and enter the discharge channels through opposing under-louver slits, "shark gills"-type louvers located on the bent and vertical sides of the louvers, respectively, while ensuring a uniform flow of the gas passing through the entire volume of the louver column. "Shark gills"-type louvers are additionally applied on the vertical and bent sides of the louvers over the entire surface or partially, on the vertical side the louvers are bent in the direction of the air flow, on the inclined side the louvers are bent in the direction of the grain flow, the "shark gills"-type louvers can have a length along the entire shaft, or be made intermittent, or be arranged staggering.

EFFECT: inventions provide a possibility to increase the specific gas supply throughout the entire volume of the drying or cooling chamber, intensify the drying process and increase the productivity, increase the homogeneity of grain drying and the quality.

2 cl, 6 dwg

Description

The invention relates to drying equipment and can be used in agricultural and other grain dryers with a gravitational moving bed, for example, louvered, core, etc.

Known gas distribution devices in a mine grain dryer (Patents RU 2269079 C1 IPC F26B 17/12 published on January 27, 2006; RU 2457413 C1 IPC F26B 17/12 published on July 27, 2012; RU 2538185 C1 IPC F26B 17/12 published on 01/10/2015; RU 169113 U1 C1 IPC F26B 17/12, F26B 25/08). Each of the devices contains an inlet and outlet chambers, as well as gas inlet and outlet ducts and half-boxes located in the drying chamber, alternating in rows, where the gas inlet ducts are connected by the open end side to the inlet chamber, and the gas outlet - to the outlet chamber located on the opposite side of the drying or cooling chamber, while the entire area or part of the side walls of the boxes and half-boxes, as well as the vertical walls are perforated.

The known devices for distributing gas in a mine grain dryer have the following disadvantages. Low efficiency and high energy consumption due to the high resistance of the perforated ducts and the grain layer to the air flow passing through them. The presence of stagnant zones during grain drying in the flow, where the material to be dried overheats and forms fires. As a result, the fire hazard increases and a periodic shutdown in the operation of the dryer is required to carry out cleaning work. The complexity of the design and the impossibility of maintaining the side walls of boxes and half boxes from the side of the grain layer.

The closest in technical essence and the achieved effect is a mine modular louver grain dryer (Patent RU 97499 U1 IPC F26B 17/12 published 09/10/2010), including a drying and cooling chamber of modules consisting of several narrow mines, separated from each other and from the walls of the module with an inter-shaft space, while the shafts are formed by a pair of vertical guides with the possibility of creating narrow grain flows in the module, on the guides themselves are located from top to bottom in several rows of louvers, bent at a certain angle into the flow.

The disadvantage of the known dryer is the uneven supply and distribution of the drying agent over the volume of grain in the mine through the under-louvred slots, which is explained by the loss of pressure due to friction and local resistance when air moves along narrow rectangular inter-shaft channels.

Low efficiency and high energy consumption due to the high resistance of the grain layer in the columns to the air flow passing through them only through the sub-louvred slots. The uneven supply of the drying agent to the grain layer causes uneven grain drying and the quality of the finished product; the danger of overheating the grain and, as a consequence, the need to reduce the intensity of drying, which leads to a decrease in the productivity of the equipment.

So the movement of grain through the thickness of the grain column will be uneven. The center layer will move at a faster speed than the layers closer to the blinds. The thickness of the wall layer of grain will depend on the flowability of the grain, the angle of repose, moisture and other properties. Also, uneven movement can be caused by the agglomeration of particles and their adhesion to the walls. Since the flow of the drying agent enters only through the jalousie slots, passes mainly through the central section of the louvered column and is discharged through the opposite checkerboard slots, the near-wall grain layers will dry longer, thereby causing uneven drying and possible overheating of the layers.

The technical problem of the invention is to increase the uniformity of grain drying and the quality of the finished product, increase the efficiency, reduce energy consumption and increase the specific gas supply to the working space of the louvered shaft grain dryer, which provides intensification of drying or cooling of grain and an increase in productivity.

The posed technical problem of the invention is achieved by the fact that in the method of gas distribution in a shaft louver grain dryer, consisting of a heated air chamber, a humid air chamber, a drying and cooling vertical chamber of modules installed one above the other to form a shaft, each module contains several narrow shafts with louvers located on them from top to bottom in several rows, separated from each other and from the walls of the module by inlet and outlet channels, it is new that the gas entering the inlet channels near each louver is divided into three streams, one of which passes through the under-louver slots , the second through jalousies of the "shark gill" type, located on the vertical sides of the jalousie and the third through jalousies of the "shark gill" type, located on the bent side of the jalousie, while all three gas flows pass through the louver column and enter the outlet channels through the opposite sub-jalousie slots , blinds such as "shark gills", located on the bent and vertical sides of the louvers, respectively, while ensuring a uniform flow of gas passing through the entire volume of the louver column.

For this purpose, in the gas distribution device on the vertical and bent sides of the louvers on the entire surface or partially, louvers of the "shark gills" type are additionally applied, and on the vertical side the louvers are bent towards the air flow, and on the inclined side the louvers are bent towards the grain flow, while blinds of the "shark gills" type can be of length throughout the entire shaft or are made intermittent, as well as staggered.

The technical result of the invention consists in improving the quality of the dried grain, the uniformity of its drying, increasing the efficiency and specific gas supply to the working space, intensifying the drying, as well as reducing the energy consumption for the drying process.

The proposed method and device for its implementation are shown in Fig. 1 is a cross-section of a module of a mine grain dryer with louvered columns with gas flows; in fig. 2 - side view of the louvered column (isp. 1); in fig. 3 - side view of the louvered column (isp. 2); in fig. 4 - side view of the louvered column (isp. 3); in fig. 5 is a top view of the louvered column; in fig. 6 is a cross-section AA of the louvered column.

A device that implements the method contains a heated air chamber, a moist air chamber and a drying and cooling chamber (not shown in the diagram). Louvered columns of the mine modular grain dryer are located in the module of the drying or cooling chamber of the mine grain dryer. The modules are installed one above the other and are sheathed with side walls 1 with thermal insulation.

In each module of the grain dryer there is an even number of louvered columns 2, installed in a staggered manner and separated from each other and from the walls of the module by supplying 3 and outlet 4 channels. The columns are fastened to each other by transverse beams. The dryer shaft is formed by louvered columns that create several narrow grain streams in the dryer. On both sides of the shaft between the louvered columns 2, plugs are installed in a staggered manner, which separate the heating chamber from the moist air chamber, preventing the drying agent from passing through the inter-shaft space and thereby ensuring the passage of the drying agent through the grain layer in the columns 2.

In the drying zone, channels 3 are used to supply gas (drying agent) from the heating chamber to the shaft, and channels 4 are used to remove the mixture of drying agent and moisture from the shaft into the humid air chamber. The channels 3 for supplying gas themselves alternate with channels 4 for removing the mixture of drying agent and moisture. In the cooling zone, cold atmospheric air enters the channels 3, passes through the shaft and enters the moist air chamber through channels 4.

Louver column 2 consists of two posts 5, on which louvers 6 are fixed from top to bottom in several rows. Louvers 6 are bent at some angle into the flow. On the vertical and bent sides of the blinds, blinds of the "shark gills" type 7 are additionally applied, and on the vertical side the blinds are bent towards the air flow, and on the inclined side the blinds are bent towards the grain flow. Blinds of the "shark gills" type can be located separately only on a vertical surface or on a bent one, and the application can be performed both over the entire surface, and partially, so that the equality of the average values of gas flow rates along the column is ensured. The application pattern for the "shark gills" -type blinds can be different, for example, along the entire length of the column (version 1), have an intermittent pattern of application (version 2), or are staggered (version 3). The application scheme will depend on the size of the louver column, the characteristics of the equipment used for the “shark gill” louvers, as well as the flow rate of the drying agent and the pressure or vacuum generated by it in the drying and cooling chamber. The application pattern of the blinds, the dimensions of the blinds and the area of their application should be selected based on the conditions for the uniform distribution of the drying agent in the layer of the material to be dried.

The device that implements the method works as follows.

Bulk material moves under the action of gravity from top to bottom and is mixed in the grain columns 2 under the action of louvers 6. The geometry of the grain layer in the louvered columns creates the necessary grain pressure, ensuring its passage without the formation of stagnant zones during the drying process.

The heated drying agent (gas) from the hot air chamber enters the mine space through the open supply channels 3 and abuts against the plugs from the side of the humid air chamber. Further, the gas near each louver is divided into three streams, one of which passes through the sub-louvre slots, the second through the “shark gill” louvers located on the vertical sides of the louvers and the third through the “shark gill” louvers located on the bent side of the louvers, while all three gas streams pass through the louvred column and enter the outlet channels. This distribution method will increase the specific gas supply while reducing the rate of its passage through the louvered slots, thereby preventing the carryover of light grain particles from the louvered column. An increase in the amount of gas passing through the grain layer will intensify the drying process. Gas flows passing through additionally applied “shark gills” louvers will move along a shorter streamline than gas flows passing only through the sub-louvre slots, which will reduce the resistivity of the grain column and thereby increase the efficiency of the dryer and reduce energy consumption. Also, the gas flows passing through the louvers of the "shark gills" type, made on the straight and bent sides of the louvers, intensify the drying of the wall layers of bulk material, thereby ensuring uniform drying throughout the thickness of the louvered column. Louvers of the "shark gill" type bent towards the grain flow on the bent sides of the louvers prevent grain from spilling out through the slots.

Application of blinds of the "shark gills" type partially on the vertical and bent sides of the blind allows to take into account the uneven distribution of potential difference (pressure difference) along the inlet 3 and outlet 4 channels between the boundaries of the gas inlet into and out of the bulk material layer. Due to this, the equalization of the average values of gas flow rates along the louvered columns is achieved.

The gas in a uniform flow passes through the grain layer located in the louvered columns 2 while heats it, gives off part of the thermal energy and takes some of the moisture and dust from the grain. After passing through the bulk material, the wet and dusty air flow (exhaust gas) through the opposite sub-louvre slots, the "shark gill" -type louvers located on the bent and vertical sides of the louvers, respectively, enters the outlet channels 4, from where it is directed into the humid air chamber.

The use of the offered louvered columns is possible in various mine grain dryers, regardless of the design of the dryer in the part of the hot and humid air chamber, the grain dryer discharge device, the loading hopper and the burner device. Louvered grain columns can be installed both in the drying and cooling chambers of the grain dryer, as well as in dryers using air recirculation.

Thus, in the proposed method and device, due to the redistribution of gas flows, a decrease in its velocity in the most dangerous zones for grain removal and an increase in the specific gas supply throughout the volume of the drying or cooling chamber, will lead to an intensification of the process and an increase in the productivity of equipment, an increase in efficiency and reducing energy consumption, as well as increasing the uniformity of grain drying and the quality of the finished product.

Claims (2)

1. A method of gas distribution in a shaft louver grain dryer, consisting of a heated air chamber, a moist air chamber, a drying and cooling vertical chamber of modules installed one above the other with the formation of a shaft, in each module there are several narrow shafts located on them from top to bottom in several rows of louvers, separated from each other and from the walls of the module by inlet and outlet channels, characterized in that the gas entering the inlet channels near each louver is divided into three streams, one of which passes through the sub-louvre slots, the second through louvers of the " shark gills ", located on the vertical sides of the blinds, and the third through the" shark gills "-type blinds, located on the bent side of the blinds, while all three gas flows pass through the louver column and enter the outlet channels through the opposite sub-louvre slits, blinds of the" shark "type gills ", located on the bent and vertical sides of the louvers, respectively, both while sintering a uniform flow of gas passing through the entire volume of the louvered column. 2. A gas distribution device in a louver-type mine grain dryer, located in a drying or cooling chamber of a modular grain dryer, consisting of several narrow shafts, separated from each other and from the module walls by an inter-shaft space, while the shafts are formed by a pair of vertical guides with the possibility of creating in the module narrow streams of grain, on the guides themselves are located from top to bottom in several rows of louvers, bent at a certain angle inward of the flow, characterized in that on the vertical and bent sides of the louvers on the entire surface or partially additionally there are louvers of the "shark gills" type, and on the vertical on the side the louvers are bent towards the air flow, and on the inclined side the louvers are bent towards the grain flow, while the blinds of the "shark gill" type can have a length throughout the entire shaft or are made intermittent, and also staggered.

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