JPS5929793B2 - Dust removal equipment in grain dryers - Google Patents

Description

[Detailed description of the invention] The present invention relates to a dust removal device in a grain dryer.

Generally, in a grain dryer, raw grain containing a large amount of straw and dust is dried with a large amount of hot air, so the dust removal device is relatively large and its exhaust pipe is also long.

Therefore, in the present invention, an axial flow fan that combines a fixed-blade wheel with a unique blade shape and a rotary-blade wheel corresponding thereto is installed in the wind exhaust pipe to blow the dust into a relatively short and small-shaped fan. The aim is to provide an overall compact device that can reliably remove dust through highly efficient centrifugation using a tube. A cylindrical wind pipe containing a built-in axial fan consisting of a rotary impeller and a fixed impeller is connected and fixed in the opening, and an annular swirl chamber is provided with an orifice tubular air outlet at the end of the extension of the wind pipe. In a device in which a small wind pipe provided on the peripheral wall of the vortex chamber is connected to a cyclone collector, the fixed blade wheel of the axial flow fan is disposed in the rear stage of the rotary blade wheel, and the fixed blade wheel is connected to the cyclone collector. The present invention resides in a device in which the arrangement shape of the wheel blades is deflected in the rotational direction of the rotary impeller.

Hereinafter, the present invention will be explained with reference to embodiment figures.
In FIG. 2, the reference numeral 1 in the figure is a grain dryer, the upper part of which is formed into a grain tank 2 and the lower part is formed into a ventilation drying chamber 3. A cylindrical wind pipe 9 with a built-in axial fan 8 consisting of a rotary impeller 6 and a fixed impeller 7
An annular vortex chamber 12 equipped with an orifice tubular air outlet 11 is fitted and fixed to the extended end portion 10 of the wind pipe 9, and a small air flow chamber 12 provided on the circumferential wall surface of the vortex chamber 12 in the centrifugal direction is fixed. The pipe 13 is connected to a cyclone collector 14, which together forms the dust removal device of the dryer as a whole.

When grain is dried in the ventilation drying chamber 3 of the dryer 10 for this purpose, since the raw grain contains a large amount of straw and dust, the exhaust air becomes a dust-laden wind containing a large amount of the dust, and the axial flow Due to the rotation of the fan 8, the dust-containing air flows inside the machine in the direction of the arrow and is absorbed into the cylindrical wind pipe 9, and this airflow moves in a spiral rotational motion within the wind pipe extension, and the annular swirl chamber 12 at the end. will reach.

During this time, the dust is subjected to centrifugal force due to the swirling of the airflow, so it drifts toward the cylindrical peripheral wall, forms a dust-containing gas layer, flows into the deep groove-shaped swirl chamber 12 at the end, and further flows into the small wind pipe 1. The dust is separated by the cyclone collector 14 via the air filter 3, clean air is discharged outside the machine from the discharge port 15 at the top, and the dust is collected in the dust box 16 at the bottom.

On the other hand, the air flowing laterally through the center of the wind pipe 9 becomes purified gas and is discharged outside the machine from the orifice tubular air outlet 11 at the end.

Next, in the present invention, in order to increase the speed of the swirling airflow in the wind pipe 9 and to enhance the centrifugal separation effect of dust contained in the airflow, the fixed blade wheel 7 is replaced with a rotary blade in the axial flow fan 8. A rotary boss 18 is pivotally attached to a rotatable shaft 17 which is arranged after the wheel 6 and protrudes from the center of the fixed blade wheel 7.
A plurality of fan-circular blades 20 are planted on the circumferential surface at appropriate angles and at appropriate intervals with respect to this axis,
In addition, in a fixed-wing vehicle, a plurality of fan-shaped blades 19 are used,
The blades 19 are arranged so as to be deflected in the rotational direction of the rotary impeller 60 so as to induce a spiral airflow, and are planted on the circumferential surface of the fixed boss 210 at appropriate intervals. Moreover, each upper edge is connected and fixed to the inner circumferential wall of the wind pipe 9, respectively.

Therefore, in the present axial fan 8, the incoming air flow is in the direction of the solid arrow (A-a-b-c-B) shown in FIG. 3.

In other words, the dust-laden wind entering from the direction of the solid hollow arrow A is
It enters in the direction of arrow a at a circumferential speed of 0 due to 60 rotations of the rotary impeller, and is influenced by the circumferential speed p at the trailing edge of the blade 20 surface, and is deflected and flows out in the direction of arrow b.

This airflow enters the fixed blade 19 from the direction of arrow C, and at the trailing edge of the blade 19, it is influenced by the warp of the surface of the blade 19 and is
The water is deflected in the direction of the arrow and flows out. At this time, the cross-sectional area between the blades is reduced at the trailing edge, so the flow speed increases and flows out.

Therefore, the airflow becomes a high-velocity spiral airflow R in the wind pipe 9 in the subsequent process, and the dust contained in the airflow is therefore subjected to a strong centrifugal force, forming a dust-containing gas layer near the peripheral wall of the wind pipe 9. form,
A purifying gas layer can be formed at the center of the wind pipe 9.

Next, the blades 22 shown as virtual images in the figure have the arrangement shape of stationary blades of a known axial flow fan, and the blades 22 are shaped so as to deflect the airflow deflected by the rotor blades in the axial direction C. Therefore, it is impossible to expect a centrifugal separation effect on dust using the axial flow fluorine.

Conventionally, the principle was that the dust generated inside the grain dryer was collected in a suitable place by the exhaust air, but in reality the equipment was not thoroughly rationalized, and the dust was actually released outdoors. This is the reality.

To accommodate this in a cyclone or other suitable dust collector, the equipment would be bulky due to the large air volume, so due to limited construction costs, it is usually left to be discharged outdoors.

The present invention utilizes the flow of a large amount of air containing dust discharged from a dryer through the stroke of the wind pipe, induces a strong swirling airflow with a unique axial fan, and transforms the wind pipe into a type of cyclone collector. The centrifugal force of the dust is applied to a part of the wind pipe, and the dust with a large specific gravity is rotated inscribed in the inner circumference of the wind pipe, and only the dust-free air flowing through the center of the wind pipe is released from the central air outlet of the orifice pipe. Since the concentrated dust-containing air flows into a small cyclone collector and the dust is discharged from the hopper, according to the device of the present invention, the pressure loss of the airflow is small, thereby increasing the separation efficiency and discharging a large amount of air. The dust contained in the air can be collected and removed, and the air can be vented outdoors as clean air that is not inconvenient for practical purposes. Furthermore, the cylindrical wind pipe can be made relatively short and small, making the entire device smaller and reducing manufacturing costs. It is also inexpensive and has remarkable practical effects, such as promoting the prevention of environmental pollution.

[Brief explanation of drawings]

Figure 1 is a side view showing the main parts of the device of the present invention in cross section;
The figure is a perspective view of the vortex chamber at the end of the wind pipe, and FIG. 3 is an enlarged explanatory view showing the arrangement shape of each impeller. 1... Grain dryer, 2... Grain tank, 3
... Ventilation drying room, 4 ... Machine wall, 5 ...
...Exhaust opening, 6...Rotor wheel, T...
...Fixed-blade vehicle, 8...Axial fan, 9...
... Cylindrical wind pipe, 10 ... Extension terminal part, 1
1... Air intake port, 12... Vortex chamber,
13...Small wind pipe, 14...Cyclone collector, 15...Discharge port, 16...
・Dust box, 17...shaft, 18...rotating boss, 19...fixing spring, 20...
Rotating blade, 21...Fixed boss, 22...
・Blade, direction of airflow...a + b g
Cz circumferential speed...Ot 9% Direction of airflow...
...A, B, C, rotation direction of the impeller...Q1
Swirling airflow...R0

Claims (1)

[Claims] 1. A cylindrical wind pipe containing a built-in axial fan consisting of a rotary blade wheel and a fixed blade wheel is connected and fixed to the ventilation opening provided in the machine wall of the ventilation drying room, and at the end of the extension of the wind pipe, In a device in which an annular swirl chamber with an orifice tubular air outlet is fitted and fixed, and a small wind pipe provided on the peripheral wall of the swirl chamber is connected to a cyclone collector, the fixed impeller of the axial flow fan is connected to the rotary impeller. What is claimed is: 1. A dust removal device for a grain dryer, characterized in that the device is disposed in a downstream process of a grain dryer, and the fixed blade wheel blades are arranged in an array shape that is deflected in the rotational direction of the rotary blade wheel.