JPH085554B2 - Powder and granular material feeder - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powdery or granular material supply device, and more specifically, when powdery or granular material is transported by pressurized air, the powdery or granular material is installed in a transportation line thereof. The present invention relates to a device for efficiently and evenly supplying.

(Prior Art) When a powder or granular material is transported by pressure air, it is important to efficiently and evenly supply the powder or granular material to a transport pipe in which the pressure air is sent and is flowing. That is, the supply device must be capable of supplying the powdery particles to the transport pipe in a fixed amount and preventing the backflow of the powdery particles due to the leakage of the pressurized air at the supply section.

Conventionally, rotary feeders and blow tank feeders have been developed and used as a feeder having such measures. Among them, the rotary feeder prevents the backflow of the powder or granular material by quantitatively supplying the powder or granular material by a large number of pockets provided around the rotor and by making the pockets airtight. The blow tank feeder is equipped with a rotary feeder similar to the above on the discharge side of the pressure tank in which the powder and granules are stored.The rotary feeder supplies the powder and granules in a fixed amount and blows pressure air into the pressure tank to disperse the powder and granules. The body is pressurized and supplied to the transportation line, and the air-tightness of the rotary feeder and the pressurized supply of the granular material prevent the granular material from flowing backward.

(Problems to be solved by the invention) Even though the rotary feeder has airtightness, it is unavoidable that minute leaks of the pressure air are unavoidable. Along with this, there was a problem that the particles flow back and dust is scattered. Although the blow tank feeder has the advantage of being able to almost completely prevent the backflow of powder and granules, it is uneconomical because it requires a large pressure tank, and it is necessary to supply a material to the pressure tank each time. The internal pressure had to be released, and there was a problem that the driving operation was troublesome.

The present invention has been made to solve the problems of the conventional device as described above, and satisfies the constant amount supply and backflow prevention required for pneumatic transportation of powder and granules, and the structure therefor is simple. It is an object of the present invention to provide a supply device that is easy to operate.

(Means for Solving Problems) According to the present invention for solving the above problems, a transportation pipe whose end is closed is horizontally connected to a lower end of a storage tank to connect the inside of the storage tank and the inside of the transportation pipe. A screw feeder is installed in the transport pipe coaxially therewith, and a diffuser part is provided in the transport pipe in front of the tip of the screw feeder, and the shaft of the screw feeder is a hollow shaft. It is characterized in that it constitutes a supply path, and pressure air is jetted and supplied from this air supply path toward the diffuser part, and when this pressure air passes through the throttle part of the diffuser part, a negative pressure is generated around it. It is what

(Operation) When the screw feeder rotates, the powder or granular material in the storage tank is quantitatively supplied to the transport pipe. On the other hand, when pressurized air is ejected from the air supply path toward the diffuser, a negative pressure is generated in the surroundings, and the jet ejector action by this causes a suction force toward the diffuser to constantly act on the powder and granules. Granules do not flow back into the reservoir.

(Embodiment) FIG. 1 shows an embodiment of the present invention, in which a transport pipe 2 is connected to the lower end of a hopper (or tank) 1 in which powder particles are stored. A part of the peripheral wall of the transport pipe 2 is open and communicates with the inside of the hopper 1, and the end is closed by a closing plate 3. A screw feeder 4 is installed in the transport pipe 2 coaxially with the transport pipe 2, and the shaft of the screw feeder 4 comprises a hollow shaft 5, which is rotatably and airtightly supported by a closing plate 3. ing. The hollow shaft 5 is connected to a rotation driving member (not shown) to rotate outside the transportation pipe 2, and is connected to a pressure air supply source to form a pressure air supply path. A nozzle portion 6 is formed at the tip of the hollow shaft 5, and a diffuser portion 7 is formed in the transport pipe 2 in front of the nozzle portion 6.

In the above-mentioned supply device, when the screw feeder 4 rotates, the powdery particles in the hopper 1 are quantitatively supplied into the transport pipe 2 by its pushing action. The supply amount is appropriately set by changing the rotation speed of the screw feeder 4. On the other hand, pressurized air is jetted and supplied from the nozzle portion 6 of the hollow shaft 5 toward the diffuser portion 7, and when the jet flow thereof passes through the throttle portion of the diffuser portion 7, negative pressure is generated in the surroundings, which causes a jet ejector action. By the cooperation of the screw feeder 4 and the extrusion action of the screw feeder 4, the supply of the powder and granules is promoted. That is, since the suction force toward the diffuser portion 7 always acts on the powdery particles, the powdery particles do not flow back into the hopper 1. When the screw feeder 4 is rotated at high speed, its screw portion acts as a screw pump, so that even if some back pressure is applied to the pipeline of the transport pipe 2, the backflow of the compressed air into the hopper is caused. That is, the backflow of the granular material does not occur.

(Effects of the Invention) The present invention provides a transportation pipe whose end is closed at the lower end of the storage tank in the lateral direction so that the inside of the storage tank and the inside of the transportation pipe communicate with each other, and the inside of the transportation pipe is coaxial with the transportation pipe. A screw feeder is installed, a diffuser portion is provided in the transport pipe in front of the tip of the screw feeder, the shaft of the screw feeder is a hollow shaft, and the hollow shaft constitutes an air supply unit. Pressure air is jetted and supplied from the air supply path toward the diffuser portion, and when this pressure air passes through the throttle portion of the diffuser portion, the granular material in the storage tank is supplied to the transport pipe in a fixed amount around it,
Due to the jet ejector action due to the negative pressure generated around the constricted part of the diffuser part, the powdery particles are always attracted toward the diffuser part, and the powdery particles do not flow back into the storage tank. The structure is extremely simple and inexpensive, and the driving operation can be easily performed without any special technique.

[Brief description of drawings]

 FIG. 1 is a vertical sectional view showing an embodiment of the present invention. 1 ... Hopper, 2 ... Transport pipe, 4 ... Screw feeder, 5 ... Hollow shaft, 7 ... Diffuser section

Claims (1)

[Claims] 1. A transportation pipe whose end is closed at the lower end of the storage tank is provided laterally in series to communicate the inside of the storage tank with the inside of the transportation pipe, and a screw feeder is installed coaxially with the transportation pipe. The transport pipe is provided with a diffuser portion in front of the tip of the screw feeder, and the shaft of the screw feeder is a hollow shaft, and the hollow shaft constitutes an air supply passage, and the air supply passage is directed from the air supply passage toward the diffuser portion. A powdery or granular material supply device, characterized in that the compressed air is jetted and supplied, and when the compressed air passes through the throttle portion of the diffuser portion, a negative pressure is generated around the compressed air.