JPS6236221A - Device for conveying powder and grain body by gas stream - Google Patents

Abstract

PURPOSE:To reduced energy consumption and lessen the wear of pipe line by providing a means of feeding a gas under pressure on the outside of an annular narrow gap and a means of feeding a powder and grin body from the outside of a gas intake pipe. CONSTITUTION:A gas intake pipe 2 is connected to the right end of a cylindrical pipe 1 via an annular narrow gap 3, and the wall surface 31 on the cylindrical pipe side of the annular narrow gap 3 is curvedly smoothly varied being shifted to the inner wall 11 of the cylindrical pipe 1. The wall surface 32 on the gas intake pipe side of the narrow gap is acutely varied at or before a position in which the wall surface 31 on the cylindrical pipe side of the narrow gap starts to vary, being shifted to the inner wall 21 of the gas intake pipe 2. When the wall surface 32 on the gas intake pipe side of the narrow gap varies acutely, the gas intake pipe 2 takes the form of an outwardly opening cone body while. When the wall surface 32 on the gas intake pipe side of the narrow gap varies at a right angle, the gas intake pipe 2 takes the form of a cylindrical shape.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel device for transporting granular materials by means of a gas stream.

A method of transporting powder and granular materials through pipes using high-speed air flow,
That is, the pneumatic transportation method is already known.

In this method, compressed air is blown into the pipe through a thin nozzle to forcefully transport the powder and granules, but the air inside the pipe becomes a turbulent flow, and the powder and granules repeatedly collide with the inner wall of the pipe in a turbulent state. Since the powder is transported, there is a drawback that not only is there a large energy loss, but also that the inner wall of the pipe is rapidly worn if the powder or granular material has high hardness. Furthermore, since a large amount of compressed air is used, energy consumption is also large.

Problems to be Solved by the Invention It is an object of the present invention to provide an apparatus capable of eliminating the drawbacks of the conventional pneumatic transportation method and transporting powder and granular materials with low energy consumption and less wear on pipes. do.

Structure of the Invention Means for Solving the Problems In the apparatus of the present invention, a gas suction pipe is connected to one end of a circular tube through an annular slit, and the wall surface on the circular tube side of the annular slit is curved. The gas suction pipe side wall of the slit changes at a right angle or an acute angle at or before the point where the circular pipe side wall starts to curve. means for supplying pressurized gas to the outside of the annular slit, the means being configured to transition to the wall surface of the gas suction pipe;

and a means for supplying powder and granules from outside the gas suction pipe,
The other end of the circular tube is characterized in that it has a structure connected to a conduit.

To explain this with reference to Fig. 1, the gas suction v2 is connected to the right end of the circular tube l via an annular slit 3, and the wall surface 31 on the circular tube side of the annular slit is curved and smooth. The wall surface 32 on the gas suction pipe side of the slit changes at an acute angle (or right angle ) is formed so that it changes and transfers to the inner wall 21 of the gas suction pipe 2.

When the wall surface 32 on the gas suction pipe side of the slit changes at an acute angle, the gas suction pipe 2 becomes a cone shape that opens outward as shown in FIG. In this case, the gas suction pipe 2 becomes circular.

FIGS. 2 and 3 show enlarged views of the slit portion when the wall surface 32 of the slit on the gas suction pipe side changes at right angles.

, Fig. 2 shows that the wall surface 32 of the slit on the gas suction pipe side changes at a right angle to the inner wall 21 of the gas suction pipe at the position (A) where the wall surface 31 of the slit on the circular pipe side begins to change in a curved line. Figure 3 shows a case in which the wall surface 32 of the gas suction pipe side of the slit is located at a point ( B) shows a case in which it is formed so as to change at a right angle and transition to the inner wall 21 of the gas suction pipe.

Further, it is not a necessary condition that the annular slit 3 be perpendicular to the inner wall 11 of the five-round tube 1, but may be inclined toward the circular tube 1 as shown in FIG.

As is clear from these figures, in either case, the pipe diameters differ before and after the annular slit, and the diameter of the gas suction pipe 2 is larger than the diameter of the circular pipe 1.

It is preferable to have a structure in which the width of the annular slit at the connection between the circular pipe and the gas suction pipe can be adjusted arbitrarily.The width of the slit is adjusted according to the amount of gas passing through to achieve the optimum passage. This is to provide speed and increase the transport efficiency of powder and granular materials.

As a concrete structure, as shown in Fig. 1, if the outer cylinder 4 directly connected to the circular pipe l and the gas suction pipe 2 are connected by a threaded structure 5, an annular shape can be formed depending on the screwing degree of the gas suction pipe. The width of the slit 3 can be adjusted as desired.

Any suitable means can be used to supply pressurized gas to the outside of this annular slit (the outer wall side of the circular pipe 1 and the gas suction pipe 2), but as shown in FIG. A gas chamber 6 is provided (using the gap between the inner wall of the outer tube 4 directly connected to the circular tube 1 and the outer wall of the circular tube 1), and this gas chamber 6 communicates with the outside of the narrow gap 3 through a communication port 61. If this is done, when gas is introduced into this gas chamber from the outside through the pressurized gas supply pipe 7, the gas will be supplied to the outside of the slit through the communication port 61.

Further, a means (indicated by a thick arrow 8) for supplying powder from outside the gas suction pipe 2 is provided. Any known means such as a screw conveyor, belt conveyor, hopper, etc. can be used as a means for supplying this powder or granular material.

The other end of the circular tube l is connected to a conduit 9.

Although any gas can be used in this device, air is usually used. In that case, the outside of the gas intake pipe 2 may be open to the atmosphere.

The transportation distance by the bag H of the present invention varies depending on the size and specific gravity of the powder or granular material, but generally it is easily about 330-100 mm. If it is necessary to transport the powder over a longer distance, the powder is supplied from the outlet of the first pipe line to the inlet of the gas suction pipe of the second apparatus of the present invention, and then the same process is carried out sequentially. It is possible to transport the required distance. That is, the device of the present invention can be used as a booster in a gas transport pipeline for powder and granular materials.

As a specific structure, as shown in FIG.
After slightly enlarging the end of 1, it is connected to a second conduit 92 via an annular slot 3 of similar construction to that shown in FIG.

In this case, the pipe line 91 of section 1 corresponds to the gas suction pipe.

When air is fed at high speed from the outside to the inside of the slit 3, the air at the exit of the slit draws a streamline inclined toward the circular pipe due to aerodynamic action (known as the Coanda effect), resulting in As a result, a negative pressure region is generated on the gas suction pipe side of the streamline. External air flows into the negative pressure region from the outside (open end) of the gas suction pipe, and the interlocking vector of the airflow from the slit and the motion vector of the airflow from outside the gas suction pipe are combined and flow toward the pipe side. Form a traveling air stream.

The amount of air traveling through the conduit is amplified several times more than the amount of air sent into the slit because of the addition of the amount of air sucked in from the outside of the gas suction tube.

When powder and granules are supplied from the outside of the gas suction pipe, the powder and granules are sucked into the airflow and transported through the pipe toward the outlet.゛The pressure of the air sent into the slit is usually 2 to 10 kg/cm2.
G level is sufficient.

The device of the present invention can also be applied to reduce the wear of the bend pipe portion of the air transport pipe for powder and granular materials. That is, lol
As shown in Fig. S6, at the outlet of the bend pipe 94 connected to the first straight pipe line 93, a second straight pipe line is connected through an annular slot 3 having a structure similar to that shown in Fig. 1. Connect to 95. In this case, the bend pipe corresponds to the gas suction pipe.

As mentioned above, the diameters of the pipes are different before and after the annular slit, so in order to make the diameters of the first and second pipes the same, the first straight pipe must be bent. It is best to slightly enlarge the diameter before connecting to the bend pipe.

In a normal bent structure, the powder and granules transported through the straight pipe 93 violently collide with the opposite wall of the bent pipe with straight energy, causing wear on the pipe wall in that part, but in the structure shown in Fig. 6, When this is done, a negative pressure area is created on the bend pipe side of the slit for the reasons already explained, so the powder and granules that were about to collide with the wall of the bend pipe are attracted to the negative pressure area and either avoid the collision or Even in the event of a collision, the collision energy is weakened, reducing wear on the walls of the bend pipe.

The most severely worn part of a bent pipe is the position where particles transported through the previous pipe line collide when they go straight, that is, the pipe wall around the approximately 45 degree transformation bend, so in the case of a bent pipe of 45 degrees or more. As shown in FIG. 7, the wear of the bend pipe can be most effectively suppressed by installing the device of the present invention between the 45-degree bend in the middle of the bend pipe and the outlet.

Example 1 The structure shown in Figure 1 has a circular tube section length of 30 cm.

At the other end of the circular pipe part of the device, the inner diameter is 5 c, m, the length of the gas suction pipe part is 30 cm, the outer inner diameter is 10 cm, and the width of the gap is 1 mm.
A transparent plastic tube with an inner diameter of 5 cm and a length of 30 m was connected, and 5 kg/cm2c of air was supplied from the pressurized gas supply pipe to supply rice grains to the inlet of the gas suction pipe, and the rice grains were transported to the outlet of the pipe. Ta. In addition, when we observed the rice grains by shining a strobe light in the middle of the pipe, it was observed that the rice grains were rotating while moving toward the outlet.

□Furthermore, despite repeated long-term experiments with different types of transport particles, there were no noticeable scratches on the inner wall of the plastic tube, and compared to the conventional pneumatic transport method, wear was reduced. There weren't many.

This may be due to centrifugal force acting as a result of air swirling, forming a compressed air layer along the inner wall of the tube, which prevents or alleviates the collision of the powder and granules with the inner wall of the tube. Presumed.

Effects of the Invention Powder and granular materials can be transported with low energy consumption and little wear on pipes.

[Brief explanation of drawings]

FIG. 1 is a sectional view for explaining the device of the present invention, FIG.
3 and 4 are partially enlarged cross-sectional views showing the structure near the slits, FIG. 5 is an explanatory diagram when the device of the present invention is used as a booster in a gas transport pipeline for powder and granules, and FIG.
7 and 7 are explanatory diagrams of the use of the device of the present invention to reduce wear on the bend portion of a pipe line.

Claims (1)

[Scope of Claims] 1. A gas suction pipe is connected to one end of the circular tube through an annular slit, and the wall surface of the annular slit on the circular tube side changes smoothly into a curve to form an inner wall of the circular tube. The wall surface on the gas suction pipe side of the slit changes at a right or acute angle at or before the position where the wall surface on the circular pipe side begins to change into a curve, and transitions to the wall surface of the gas suction pipe. and a means for supplying pressurized gas to the outside of the annular slit, and a means for supplying powder from the outside of the gas suction pipe, and the other end of the circular pipe is connected to the pipe line. 1. A device for transporting powder and granular materials by means of a gas flow, characterized by having a structure in which: 2. Transporting powder and granular material by the gas flow according to claim 1, characterized in that the width of the annular slit at the connecting portion between the circular pipe and the gas suction pipe can be arbitrarily adjusted. device to do. 3. An apparatus for transporting powder or granular material by means of a gas flow according to claim 1, which is provided at the outlet or in the middle of a bend pipe.