JPS5841252B2 - Crosslink breaking device for powder and granular materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and an apparatus for destroying the crosslinking phenomenon that occurs when powder and granular materials are discharged from a storage tank, thereby making the discharge from the storage tank smooth.

Conventionally, methods for easily discharging powder and granules from a storage tank include vibrating the storage tank wall and flowing low-pressure compressed air through porous cloth or plates to fluidize the powder and facilitate discharge. However, in the event that crosslinking occurs inside the storage tank and it becomes impossible to drain it, there is no definitive way to remove it, such as manually poking it out from the bottom with a stick, or hitting the storage tank wall from the outside. Currently, methods such as having a person enter the tank from the top and break the bridge are used.

Therefore, introduction of low-pressure compressed air into the storage tank has been considered as one of the means to prevent the crosslinking phenomenon.

However, compressed air may fill the storage tank and flow back into the falling particles, or air mixed with powder may leak from the storage tank, or the purpose of breaking bridges may not be fully achieved, or there may be serious problems in practical use. It contained problems.

As a result of various studies, the inventor of the present invention found that the amount of air injected does not matter in order to break the bridge.

I learned that if the injected air has high energy, crosslinking can occur in a short period of time and just by injecting a small amount of air.

It is necessary that the air injection be for a short time, within one second, and that the air flow velocity be approximately the speed of sound at the position of the injection port.

As in the injection of the present invention, a high-energy injection with a wind velocity of the speed of sound is performed in a short period of less than one second, that is, a jet stream injection is performed.

If necessary, the above-described short-time injection may be repeated after a period of time.

In this way, the amount of air blown may be 0.4 m''/min for a tank capacity of 100 m''.

In the conventional method, the tank is continuously 2m/40m°.
It takes about a minute.

According to the present invention, there is no backflow of airflow, no powder leakage, etc.

The present invention makes use of a jet stream to destroy bridges.

According to the present invention, a jet airflow close to the speed of sound is sprayed once or several times intermittently in a short period of less than 1 second. The resulting air hammer effect allows the purpose of crosslink destruction to be achieved reliably and easily.

Further, in order to achieve the present invention, the injection airflow by a rapid exhaust device using a diaphragm is an important component.

The use of a diaphragm valve makes it possible to inject a high-energy airflow in a short period of time.

It has been found that the objectives of the present invention cannot be achieved with just a conventional compressor without a diaphragm valve.

In the accompanying drawings, FIGS. 1 and 2 show the apparatus according to the present invention installed in a storage tank undergoing general crosslinking, but the apparatus shown in FIGS. 3 and 4 may also be used for crosslinking. It shows a similar crosslinking breaking effect.

In these figures, 1 is a storage tank for storing powder and granular material 2;
4 shows the crosslinks generated in the powder and granules, and 4 shows the crosslink breaking device according to the present invention.

Now, the bridge breaking device according to the present invention will be explained with reference to FIGS. 5 and 6.

The bridge breaking device 4 shown in cross section in FIG. It consists of an air launch tube 8 connected to a storage tank (1 in FIGS. 1 to 4) for bodies, etc.

The air storage tank 5 is provided with an air supply 9, from which compressed air is introduced by means of a valve 10 via an air line 11 from a suitable compressed air source (not shown).

The air pressure in the tank 5 is detected by a pressure gauge 12, and when the set pressure is reached, the valve 10 is closed.

FIG. 6 shows an enlarged view of the interior of the operation chamber 7.

The operation chamber 7 consists of a cylindrical tube 13 provided with flanges at both ends, and an end plate 14 and a hemispherical end member 15 that are airtightly attached to both ends of the cylindrical tube 13 by the flanges.
is connected to the neck 6 at its body and communicates with the tank 5.

Inside the operation chamber 7, an air launch tube 8 is airtightly supported by the end plate 14, and one end thereof (the left end in FIGS. 5 and 6) protrudes by a length outside the operation chamber 7 and is open. The other end (the right end in FIGS. 5 and 6) is connected to an opening provided on the wall near the powder discharge port of the storage tank 1 (see FIGS. 1 to 4). extends deep into the control room 7 and is open.

On the other hand, in proximity to the other end of the air launch tube 8, a diaphragm 16 is supported at a flange portion where the cylindrical tube 13 constituting the operation chamber 7 and the end member 15 are attached.

A spring 17 is disposed between the diaphragm 16 and the end member 15 on the opposite side of the air firing tube 8, and in a normal state, it pushes the diaphragm 16 to the left in the figure and connects it to the other end of the air firing tube 8. Pressed in an airtight manner.

A suitable number of pinholes 18 having a diameter of approximately 2 mm are formed in the diaphragm 16, and the spaces on both sides of the diaphragm 16 inside the operation chamber 7 are communicated through these pinholes.

The operation chamber 7 is provided with an air outlet 19.
There is a valve 20 for venting through 9.

Next, the operation of the destruction device of the present invention will be explained.

First, prior to operation, insert and connect the tip of the air ejection tube 8 of the device 4 into an opening provided at an appropriate location near the powder discharge port of the storage tank 1 where cross-linking has occurred (Figs. 1 to 4). reference).

At this time, the inside of the air launch tube 8 is maintained at atmospheric pressure or the powder pressure in the storage tank, and the back pressure of the one-way diaphragm 16 is maintained at the same pressure as the compressed air pressure in the tank 5 via the pinhole 18. ing.

Since the air force inside the tank 5 is higher than the atmospheric pressure or the powder pressure (0.1 to 0.2 kg/cmt if the powder is wheat flour), the diaphragm 16 is strongly pressed against the other end of the air launch tube 8, that is, the right end surface in the figure. As a result of being held down, air tank 5
There is no air leakage, and the initially set air pressure can be maintained indefinitely.

In order to shoot compressed air into the storage tank 1, the pressure in the space on the right side of the diaphragm 16 is suddenly reduced to atmospheric pressure by opening the valve 20. The compressed air in the air tank 5 passes through the gap between the diaphragm 16 and the air launch tube 8, and is ejected through the air launch tube 8 at nearly the speed of sound.

This air flow condition is shown in FIG.

FIG. 7 shows the pressure distribution at a position 1 m away from the device when the device is operated in the atmosphere.

From this figure, it can be seen that a shock wave with very strong directionality is emitted from the air launch tube 8.

This device is capable of ejecting compressed air in a short period of time, and therefore can directly hit the powder bridge with a high-energy compressed air mass.

Furthermore, the firing pressure can be changed depending on the degree of crosslinking.

Because it has an air reservoir, it has features such as being movable and being able to be used in locations far away from the air source without the need for piping or other trouble.

Furthermore, in the present invention, the compressed air is passed through the diaphragm.

Therefore, not only is the structure simple, but it can be easily replaced in the event of a failure or periodically, which is extremely convenient in terms of maintenance and operation of the device.

Next, examples will be shown in which the crosslink breaking device according to the present invention was used.

Example 1 37 tons of powder (flour with poor fluidity) was put into a square concrete storage tank with a capacity of 50 tons and left for one month.

After confirming that it is not being discharged by normal discharge means and that crosslinking has occurred in the storage tank, the device is installed in the state shown in Figures 1 and 2 using a diaphragm valve with an air tank pressure of 5 kg/aft and a capacity of 8M. The injection device used in Figure 5 was operated three times for 50 seconds, resulting in very rapid discharge.

Example 2 3 tons of flour was put into a round iron plate storage tank with a capacity of 5 tons, and 1
After storing for a week, confirm that cross-linking has occurred, and blow a jet stream of 340 m/min onto the cross-linked area using compressed air with a pressure of 2 kg/self and a capacity of 851 stored in an air storage tank, and operate it 4 times for 30 seconds. However, the flour was quickly discharged.

Next, we will discuss how to use this device effectively.

In general, the particle size of the stored powder and granules varies from small powders such as wheat flour to large grains, but in most cases there is only one type of powder and granules, and when storing many types of powder and granules in the same storage tank, few.

Whether or not crosslinking occurs in the storage tank is determined by the properties of the powder, such as particle size and wetness, the smoothness of the inner wall of the storage tank, the slope of the wall near the outlet, and the storage height.

In addition, if the number of storage tanks is large enough to contain groups of several tens of water, as shown in Figure 8, this device should be installed on the ground, the piping should be routed to minimize bends, and a diaphragm valve installed in the middle of the piping should be used. Set the device operating tank by opening and closing.

Furthermore, if remote control or the like is required, the valves 10 and 20
By replacing it with electromagnetic pulp, etc., electrical on/off
It is possible to enable operation only by turning it off.

If the powder storage tank is located far from the air source and it is difficult to install piping to connect it, fill the air tank with compressed air and then move the entire device close to the storage tank. I can do it.

[Brief explanation of the drawing]

1 to 4 are diagrams showing the bridge-breaking device according to the present invention applied to various types of bridges, FIG. 5 is a schematic cross-sectional view of the bridge-breaking device according to the present invention, and FIG. 6 is a diagram showing the structure shown in FIG. 4. 7 is a diagram showing the pressure distribution of the jet air of the bridge breaking device according to the present invention, and FIG. 8 is a schematic diagram showing another application example of the present invention. 1...Powder storage tank, 2...Powder and granule, 3
...Crosslinking, 4...Bridge breaking device, 5.
... Compressed air storage tank, 6 ... Neck, 7 ... Control room, 8 ... Air launch tube,
9... Air inlet, 10, 20... Valve,
11...Air piping, 12...Pressure gauge,
13... Cylindrical tube, 14... End plate, 15
... Hemispherical end member, 16 ... Diaphragm, 17 ... Spring, 18 ... Pinhole, 19 ... Air outlet, 20...
valve.

Claims (1)

[Claims] 1. A tank having a compressed fluid inlet, an operation chamber communicating with the tank and having a fluid outlet, and a fluid jet airtightly supported within the operation chamber, with one end open outside the operation chamber and the other end open inside the operation chamber. a diaphragm having a pinhole is fixed to the wall of the operation chamber adjacent to the other end of the fluid injection tube in the operation chamber, and the diaphragm is disposed between the diaphragm and the wall of the operation chamber. A bridge breaking device characterized in that a spring is provided for tightly contacting the other end of the fluid injection pipe, and an on-off valve is provided at the fluid discharge port of the operation chamber.