JP2000264440A - Pneumatic transporting method and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower the pressure loss of a transporting pipe line to improve the transporting efficiency by a jet pump, to prevent the consolidation in a hopper and to assist the supply of a solid matter to the jet pump by providing the transporting pipe line with a bypass line and recharging the transportation air to the hopper from the transporting pipe line through the bypass line. SOLUTION: A molten resin 5 is cooled by a cooling part 6, ground by a grinder 7, and charged into a hopper 1. Then the resin as the ground solid matter is pneumatically transported by a jet pump 2 through a transporting pipe line 3. At this time, the ground resin is sometimes consolidated by the self weight and is not completely sucked only by the suction force of the jet pump 2. To cope therewith, the transporting air from the jet pump 2 is recharged to a bottom of the hopper 1 from the transporting pipe line 3 via a bypass line 4 whereby the jetting amount of the jet pump 2 is increased, while reducing the pressure loss of the transporting pipe line 3 to improve the transporting efficiency of the solid matter, and to prevent the consolidation of the resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for pneumatically transporting powder.

[0002]

2. Description of the Related Art A pump of a type in which a surrounding fluid is swept by ejecting a fluid is well known as a jet pump. Spout pumps are generally simple in construction and have no mechanical moving parts, so they have few failures and are used for transporting fluids containing solids. However, in this method, since the ejected fluid and the fluid containing solid matter to be transported all flow through the same transport pipeline, the pressure loss of the transport pipeline is larger than that of a general pneumatic transport system. . And when you try to transport more solids,
It is necessary to increase the fluid to be ejected, and the pressure loss further increases. As a result, the increase amount of the fluid containing the solid matter to be transported gradually decreases with respect to the increase amount of the fluid to be ejected, and the transport efficiency is reduced.

[0003] As a method of preventing the reduction of the transportation efficiency,
A method has been adopted in which a hole is made in the middle of the transport pipeline to release a part of the fluid to reduce the pressure loss. A specific method is disclosed in, for example, JP-A-6-263250. ing. However, even with these methods,
If fine powder is contained in the solid matter to be transported, it will be partially contained in the escaped fluid, and discharging it out of the system may lower the yield in some cases.

On the other hand, in a pneumatic transport system called a blow pot system, compressed air is supplied to a blow pot in which a hopper is closed to assist supply to a pneumatic transport means. Further, in order to prevent the solid matter in the hopper from being condensed and becoming difficult to be fluidized, air is supplied from a lower solid matter filling portion of the hopper to float the solid matter, thereby improving the flow state. Thus, when the above methods are combined, on the other hand, air is discharged out of the system,
On the other hand, you have to take the air into the system,
From the viewpoint of energy saving, there is a problem that it is very wasteful.

[0005]

According to the present invention, in order to solve the above-mentioned problems, a pneumatic transportation method is provided, wherein a bypass is provided in a transportation pipeline and transportation air is re-input from the transportation pipeline to a hopper. And a device therefor, and by further devising a re-feeding position to the hopper, the fluidity of the solid material is increased and the transport amount is increased.

[0006]

Embodiments of the present invention will be described below with reference to examples. (Embodiment 1) FIG. 1 shows an embodiment of the present invention. The present embodiment is an apparatus for transporting solid matter using a jet pump 2. The molten resin 5 is cooled by a cooling belt 6, then crushed by a crusher 7, put into a hopper 1, and then crushed. The resin is transported by air. The crushed resin is compacted by its own weight, and often cannot be completely sucked only by the suction force from the rear end of the jet pump 2. In order to eliminate the compaction, a pipe is conventionally provided at a lower portion of the hopper 1. The resin was floated by sending air to facilitate suction from the jet pump.

In the present embodiment, the transport air from the jet pump is recharged from the transport pipe 3 to the bottom of the hopper 1 through the bypass 4. Since the jet flow rate can be increased, the transport amount of solids can be increased, and the resin can be prevented from being compacted. Although the hopper 1 used in the present embodiment has an upper part in an open state, the hopper 1 may be in a closed state as in the blow pot method. The bypass 4 may be provided with a control means such as a valve for controlling the air flow rate.

As the jet pump 2 used in the present invention, for example, a jet pump of a peripheral nozzle type as shown in FIG. 3 can be used. The shape of the outer peripheral nozzle 33 is not particularly limited, and may be, for example, an annular shape. This nozzle 3
3, compressed air 34 by a compressor or the like.
Is supplied. Since the outer peripheral nozzle 33 faces the horizontal conduit 32 which is the transport direction, the rear end side of the nozzle 33 is
Negative pressure occurs. Therefore, the solid substance 37 is sucked from the rear end of the outer peripheral nozzle type jet pump 31 and flows through the transport pipeline. The jet pump 2 may be of a type that jets air from the center instead of the outer periphery.

The position of the bypass 4 of the present invention is not particularly limited. However, in consideration of the stability of the fluid, it is preferable that the bypass 4 is installed at a point past an acceleration region generally called by the jet pump 2. On the other hand, in order to more sufficiently reduce and decrease the pressure loss, a point as close as possible to the jet pump 2 is preferable, and an optimal position is appropriately determined according to each transport condition.
Further, for the purpose of sufficiently floating the solid matter, the outlet of the bypass air may be branched in the hopper, or a plurality of inlets of the bypass 4 may be provided.

(Embodiment 2) FIG. 2 shows another embodiment of the present invention. In the present embodiment, an example of a blow pot method will be described. That is, the hopper is separated into a hopper (1) 19 for receiving and temporarily storing the crushed resin and a pressurizable hopper (2) 11 partitioned by a double damper 18, and the bypass 14 is connected to the hopper (2). 11 to the upper space. By doing so, the inside of the hopper (2) 11 is pressurized, and the resin in the hopper (2) is
Since it is pushed out to the second side and assists the suction of the jet pump 12, the effect of increasing the transport amount of solids can be expected as in the first embodiment. The position of the bypass 14, the presence or absence of a valve and the like, and the jet pump are the same as those in the first embodiment.

[0011]

As described above, according to the present invention, the pressure loss in the transportation pipeline is reduced, and particularly, the transportation efficiency by the jet pump is increased, and at the same time, the compaction in the hopper is prevented.
The supply of solids to the jet pump can be assisted.
Furthermore, the effect is also very useful in the chemical industry because it contributes to energy saving by effective use of pneumatic power.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing one embodiment of the present invention.

FIG. 3 is a diagram showing an outer peripheral nozzle type jet pump as an example of a jet pump used in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hopper 2 12 Jet pump 3 13 Transport line 4 14 Bypass 5 15 Resin 6 16 Cooling belt 7 17 Crusher 11 Hopper (2) 18 Double damper 19 Hopper (1) 31 Outer nozzle type jet pump 32 Horizontal pipe 33 Outer circumference Nozzle 34 Compressed air 37 Solid

Claims (6)

[Claims] 1. A pneumatic transport method comprising providing a bypass in a transport pipeline and re-feeding transport air into a hopper. 2. The pneumatic transportation method according to claim 1, wherein the transportation air is recharged from an upper space portion of the hopper. 3. The pneumatic transportation method according to claim 1, wherein the transportation air is recharged from a lower powder filling portion of the hopper. 4. A pneumatic transport apparatus comprising a hopper, a jet pump, a transport pipe, a bypass connecting the transport pipe and the hopper, and transporting solids while re-feeding transport air into the hopper. 5. The pneumatic transport device according to claim 4, wherein the transport air is re-input from the upper space of the hopper. 6. The pneumatic transportation device according to claim 4, wherein the transportation air is re-charged from a lower solid material filling portion of the hopper.