JPH0462970B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a pressure-feeding pneumatic transport device that can continuously transport a fixed amount of powder or granules at low speed and high concentration using a high-pressure air source of a compressor. Using a rotary feeder, which could only be used in high-speed, low-concentration systems using a low-pressure air source such as a blower, the rotor's rotating shaft was eccentrically supported in a cylindrical casing with an upper opening and a lower opening. The tip of the blade can come into contact with the inner peripheral surface of the casing near the upper and lower openings due to the pressure difference between the upper and lower passages, and by using the compressor as the air source, continuous quantitative supply and transportation can be realized. The present invention relates to a pressure-feeding pneumatic transportation device that can reduce friction between particles and pipe walls during the transportation of new materials, composite materials, etc. during the handling process.

BACKGROUND TECHNOLOGY In general, low-speed transportation in a pressure-feeding pneumatic transportation method for powder and granules means that the amount of transportation is small, and the mass flow rate of the conveying air decreases as the diameter of the transportation pipe decreases from approximately 2 to 12 kg/m ² . In contrast, high-speed transportation refers to a pneumatic transportation method that uses a Roots blower or turbo blower with a discharge air pressure of less than 1 Kg/cm ² as the air limit, which is 12 Kg/m2. Transport is performed at a mass flow rate exceeding ² ·s, and is a low-concentration transport method mainly suitable for medium-distance transport.

In the aforementioned low-speed transportation method, a compressor with a normal pressure of about 5 to 7 kg/ ^cm2 is commonly used as an air source.
As a storage supply source for powder and a delivery mechanism into a transportation pipeline, it is essential to install a cellar-type or fluxo-type blow tank that complies with regulations for pressure vessels.

An explanation will be given based on FIG. 7, which shows an example of a configuration in which a conventional low-speed transportation system employs a twin cellar type tank.The powder and granular materials to be transported, which are fed into the supply hopper installed at the top, are, for example, corn, etc. By opening and closing the valve, the material is charged into the cellar-type blow tank 20b under atmospheric pressure.

At this time, from the multiphase delivery pipe 21 connected below the other blow tank 20a, the powder and granules are delivered in a plug-like lump (hereinafter simply referred to as a plug) within the pipe, and the powder and granules are delivered from the end of the delivery pipe 22. It is slidably transferred within the transportation pipeline system 23 connected to the .

During this time, the primary air nozzle 22, together with the secondary air nozzle 24 and the back pressure nozzle 25, are connected to a compressed air pipe 26 that communicates with the high pressure air source, and each is connected to one
By mutually adjusting at least three or more nozzles such as the secondary, secondary, and back pressure nozzles, the plug is transported by a plug-like flow in which it slides inside the pipe.

However, it is unavoidable that the amount transported changes when batches are switched, and as the level of stored powder and granules changes within the same batch, the amount sent to the transportation pipeline changes, and the effect of fluctuations in the sending section increases. Furthermore, as a ripple effect, the plug is crushed within the transport pipe, and it is difficult to reform it after being crushed, and the accompanying fluctuation in the amount of transport cannot be prevented.

In order to solve the problems of such a batch switching system, a configuration has been proposed in which blow tanks are stacked in two stages in series in the vertical direction, and continuous delivery is achieved by switching between upper and lower dampers.

In this configuration, in addition to the fact that the length of the plugs and their intervals are not constant, the change in the delivery amount due to the extrusion supply is limited to adjusting the flow rate of the blowing compressed air, which has a mass that is less than 1/1000th of the delivery amount. quantification is not ensured, e.g., quantitative delivery by mechanical force.
Fluctuations in the delivery amount have not been resolved.

In addition, since sealed blow tanks are stacked in two layers (top and bottom) as pressure vessels, the cost of transporting objects to the hopper at the top of the tank due to the installation height is lower than that of the twin-hulled type. There is also the problem of significantly higher costs.

Next, a known configuration example of the high-speed transportation method, which is the most common transportation direction, will be explained based on FIG. 8.
Powder to be transported is put into the hopper 27 under atmospheric pressure, and by the rotation of the low-pressure rotary feeder 28, it is dropped and discharged from the discharge opening at the lower end into the mixing acceleration chamber 29 below, and is discharged from the transport pipe. A configuration is known in which the system 23 continuously transports a fixed amount to a separation cyclone and a storage silo.

The air source in this case is usually 0.3 to 1.0
Kg/cm ² turbo blowers or roots blowers are used.

These conventional low pressure rotary feeders 28
The reverse differential pressure between the atmospheric pressure side on the input side and the discharge side is greatly influenced by the difference in the properties of the powder or granular material to be transported, but it is possible to input and supply with a limit of 0.5 to 1.5Kg/ ^cm2 . It is also said that a fixed amount of supply can be secured.

Therefore, in general, even if it is a low-speed, high-concentration transportation method using a compressor as an air source or a high-speed, low-concentration transportation method, in a long-distance, high-pressure transportation method where the pressure loss exceeds 1.5 Kg/ ^cm2 , it is difficult to push high-pressure air. In order to transport the material to be transported into the transportation pipeline system, a blow tank is an essential component as in the conventional example, and its quantitative supply function has conventionally been limited to low-pressure air sources. It was thought that it would be impossible to put into practical use a low-speed, high-concentration transport system incorporating the rotary feeder mechanism.

The rotary feeder has a simple structure in which the rotor rotates within the casing, and it can easily isolate the upper and lower passages outside the casing with the required pressure difference, allowing a fixed amount of powder to fall while maintaining airtightness. It is widely used for supplying or mixing powder and granules into transportation systems because it can be supplied in a fixed quantity as desired by adjusting the rotational speed of the rotor.

Problems to be Solved by the Invention In general, rotary leaf feeders cut off the pressure in the transportation system and use gravity to drop the powder and granules, so the smaller the gap between the rotor and the casing, the better. In order to solve processing and manufacturing problems such as assembly, or operational problems where rotational resistance becomes excessive due to entanglement of powder or granules or thermal expansion of the rotor, making operation difficult.
It is necessary to create an appropriate gap between the casing and rotor.

By the way, the gap between the casing and the rotor increases as the pressure difference between the top and bottom of the casing increases, so the amount of pressure gas leaking increases.As the apparent specific gravity of the transported object decreases, the backflow of the leaked gas causes the transported object to leak. The amount of drop may decrease or become uneven, making it difficult to supply a constant quantity.

Therefore, the limit of the pressure difference between the upper and lower passages outside the casing that can be used with the rotary leaf feeder is usually
For example, in the case of granules with an apparent specific gravity of about 0.5T/ ^m3 , it is 6000~
The practical limit was 7000 mmH ₂ O, and about 3000 to 4000 mmH ₂ O for powder, which was thought to be invincible for long-distance high-pressure transportation systems.

However, recently, when transporting powder and granular materials such as ultrafine or surface-activated composite materials by air, it has become desirable to achieve higher transport pressures in order to improve the efficiency of pneumatic transport. Ta.

This invention prevents deterioration of properties such as crushing, abrasion, and quality deterioration during pneumatic transportation of various powder materials such as ultra-finely divided or surface-activated composite materials, and reduces equipment costs and operating costs. The purpose of this project is to provide an inexpensive, low-speed, high-density pneumatic transportation method.

Further, the present invention provides a high-pressure pneumatic transport device that can continuously supply a fixed amount and perform stable pneumatic transport when carrying out short-distance, low-speed, high-concentration transport and long-distance, high-speed, low-concentration transport using a compressor as an air source. The purpose is to

Means for Solving the Problems The inventors conducted various studies on improving the rotary leaf feeder itself with the aim of realizing a transportation method using higher pressure air in pneumatic transport of powder and granular materials using the rotary leaf feeder. As a result, by eccentrically supporting the rotating shaft of the rotor in the casing, the rotor is pushed according to the pressure difference between the feeding system and the transport system. For example, when the transport system is under high pressure, the rotor is moved upward. It was discovered that by moving to the opening side and being able to rotate with close to zero clearance with the casing, leaks due to pressure differences were prevented, making it possible to transport powder and granular materials using air at a higher pressure than before. .

Furthermore, when using this rotary leaf feeder in a pressure-feeding pneumatic transport device, the inventors investigated the optimal application conditions and found that a multi-phase feeder with a hopper and a blowing nozzle installed in the upper and lower openings of the rotary leaf feeder was developed. An inlet pipe is provided, and a compressor capable of producing compressed air of 1.0 Kg/cm ² or more is used as the compressed air source to communicate the rotor chamber filled with powder in the casing and the rotor chamber on the return side, which rotates in the opposite direction. However, they discovered that low-speed, high-density pneumatic transport could be realized by introducing return-side rotor chamber pressure into the rotor chamber filled with powder and granules, and completed this invention.

In other words, the present invention has a rotor built into a cylindrical casing having vertical openings vertically with a rotating shaft supported horizontally and eccentrically. The inlet of the rotary leaf feeder, which can come into contact with the inner circumferential surface of the casing around the inlet or outlet, is connected to a hopper that is exposed to low pressure or the atmosphere, or a chute tube is connected to the inlet, and as required for the outlet. It consists of a multiphase inlet pipe with a blow nozzle and a transport pipe connected to its tip, with a drop tube connected accordingly, and the return side rotor chamber pressure to the casing is transferred to the rotor filled with powder and granules. This is a pressure-feeding air transport device characterized by providing a communication path leading into the chamber and connecting a compressor capable of producing compressed air of 1.0 kg/cm ² or more to the blow nozzle.

Function This invention provides a system in which the lower part of the hopper, which is released to the atmosphere and into which the powder or granular material to be transported is charged, is connected to the inlet on the upper end surface of the above-mentioned special rotary leaf feeder compatible with high pressure, and communicated with the compressor. A multiphase feed pipe with a blow nozzle fitted and arranged at a required angle is connected, and its downstream end is connected to a transport pipeline system. Can be transported continuously by air.

In other words, one of the features of this invention is that the rotor is housed horizontally and eccentrically in the casing in order to increase the reverse differential pressure of the so-called rotary feeder. A joint that allows the rotor rotating shaft and the rotation transmission shaft supported by the casing to be eccentric, or as shown in Fig. 4,
A flexible joint 43 may be interposed between the rotor rotating shaft 41 and the rotating shaft 42 supported on the casing side, or the end of the plate-shaped rotating shaft may be loosely fitted into another rotating shaft having a groove in the diametrical direction. Various known means were selected, such as providing a mechanically engaging portion that allows the rotor to rotate freely between the rotor rotation shaft and the rotation transmission shaft supported on the casing, and the rotor rotation shaft is eccentric to the rotation transmission shaft supported on the casing. In addition to freely supporting the rotor, the rotor may be free and eccentric to the rotating shaft supported in the casing.For example, as shown in FIG. 3, a fitting hole larger than the outer diameter of the rotating shaft 42 A rotor 40 provided with a rotor 40 is loosely fitted onto a rotating shaft 42 whose center portion is plate-shaped, and rotation can be transmitted by engagement of a protrusion or ridge 40a provided on the inner circumferential surface of the rotor with the rotating shaft 42 having a predetermined shape. Or, furthermore, the rotor is incorporated eccentrically and a known configuration capable of transmitting rotation is appropriately selected, such as not supporting the rotating shaft at both ends but only supporting one side of the shaft as shown in FIG. be able to.

Further, the blades of the rotor can be appropriately selected from so-called parallel type, helical type, W-helical type, etc. depending on the type of powder or granular material, and the number of blades can be similarly selected as appropriate for the purpose of continuous quantitative determination.

The shape of the inlet can be appropriately selected depending on the type of powder or granular material, such as a full-face opening or an inclination with respect to the rotor rotation axis.

Furthermore, the present invention is characterized by a configuration in which the return side rotor chamber pressure is introduced into the rotor chamber filled with powder. Specifically, this can be achieved by providing a conduit that communicates the rotor chamber filled with the powder inside the casing and the rotor chamber on the return side that rotates in the opposite direction.

Furthermore, in order to prevent the communication pipe from being clogged with powder or granules, a pipe through which compressed air from a compressor can be introduced may be provided.

In addition, in this invention, as shown in FIG.
Rotary feeder casing 3 as required
1, the chute tube 2 is connected to the inlet port 32, and the drop tube 4 is connected to the outlet port 33. Ida 3
This is to provide a stirring and mixing effect to assist in quantitative discharge from the water.

The preferred dimensional ratio of each cylinder provided as necessary is the inner diameter D ₁ of the chute cylinder 2, the cylinder height h ₁ , and the drop cylinder 4.
The inner diameter of the drop tube 4 is D ₂ , the height including the different diameter pipe 5 provided between the multiphase feed pipe 7 is h ₂ , the diameter of the upstream inlet end face of the multiphase feed pipe 7 is D ₃ , If the diameter of the outlet end face on the downstream side is D ₄ , the inner diameter D ₁ of the chute cylinder 2 is
The diameter is approximately equal to or does not exceed the opening cross-sectional area of the inlet 32 of the rotary feeder, and the height of h ₁ is preferably 0.5×D ₁ to 1.5×D ₁ .

Furthermore, regarding the drop tube 4, D ₂ is a diameter equivalent to the tube cross-sectional area that is approximately equal to or not less than the opening cross-sectional area of the inlet 32 of the rotary feeder;
The height of h ₂ is preferably 1×D ₂ to 3×D ₂ .

For the multiphase feed pipe 7, D ₃ ≦D ₂ , D ₃ ≧1.5×
D ₄ , and D ₄ is preferably equal to the pipe diameter of the transport pipe system 8 .

In order to achieve low-speed, high-density air transport, the compressed air injected from the blow nozzle must be 1.0 kg/1.0 kg by a compressor.
High pressure air of at least cm ² is required, preferably
1.5Kg/cm ² or more, more preferably 2.0Kg/cm ²
That's all.

Next, the pressure balance of each part of the device during steady operation is as follows: The pressure inside the hopper 1 is P ₀ , the rotor chamber inside the casing 31 of the rotary leaf feeder, the pressure on the side where the transported material is filled and rotated is P ₁ , The pressure on the reverse side is P ₂ , and the pressure on the upper inner side of the drop tube 4 is
P ₃ , and when the high pressure air source pressure of the blowing nozzle 6 is P ₄ , the continuous quantification under the above-mentioned reverse high differential pressure is balanced by P ₀ < P ₁ ≦ P ₂ ≦ P ₃ ≦ P ₄ . This can be said to be a necessary condition for regular pneumatic transportation in supply.

Embodiments Embodiment 1 An example of a pneumatic transportation device according to the present invention will be explained based on FIG. 1.

Materials to be transported are put into a storage container, for example, a hopper 1 whose lower end is conically constricted, and a chute tube 2 is connected to the lower end of the hopper 1, and a high-pressure rotary leaf feeder 3 according to the present invention is connected to the lower end of the hopper 1. It is connected to an inlet 32 on the upper end surface of the casing 31, and a drop tube 4 is connected to a drop tube 4 hanging down to an outlet 33 on the lower end surface.

Subsequently, the powder particles falling from above are formed into a solid-gas mixed phase flow or a plug flow by a blowing jet from a compressor (not shown), and are introduced and conveyed into the transport pipe system 8. A multiphase inlet pipe 7 is connected to the drop tube 4 via a pipe 5 of different diameter whose diameter is temporarily reduced.

The multiphase feed pipe 7 is bent at a right angle, and its downstream end face is connected to the starting end inlet of the transport pipe system 8 with the pipe diameter reduced to the same diameter, and a blow nozzle 6 is inserted and arranged near the bending point. is constructed such that compressed air from the compressor can be injected as a jet toward the starting end inlet of the transport pipe system 8.

The objects to be transported which are charged and stored in the hopper 1 fall into the charging chute pipe 2 connected at the lower end and are filled.

The high-pressure type rotary feeder 3 has been put into practical use with a mechanism whose design concept is completely different from that of conventional low-pressure types. is formed in an elliptical cross section with the vertical axis vertical, and the rotating rotor 3
4 has its blade end surface cut into a perfect circle, and its diameter is slightly smaller than the minor axis of the elliptical cross section.

Further, the shaft hole 36 of the rotor 34 is connected to the drive shaft 35.
is formed in a floating bearing structure in which the rotor 34 is rotated by floating, and when the pressure on the outlet 33 side of the rotary leaf feeder 3 is larger than the pressure on the inlet 32 side. As shown, rotor 3
4 is lifted from below to above, and rotates while being in close contact with the upper circumferential inner surface of the portion near the lower end of the side surface of the inlet 32.

That is, at least two of the blade ends of the rotor 34 rotate so that they are always sliding in direct contact with the circumferential inner surface of the casing 31 with zero clearance, and the number of blades of the rotor 34 and the specifications of the rotary leaf feeder 3 are fixed. It is necessary to design and manufacture.

Furthermore, the casing 31 is provided with communication holes 37 and 38 for providing a conduit that communicates the rotor chamber filled with the powder inside the casing and the return side rotor chamber on the opposite rotation side. This is a configuration in which rotor chamber pressure is introduced into the rotor chamber filled with powder and granules.

In this case, it greatly contributes to reducing the amount of leakage under the reverse height differential pressure of the rotary leaf feeder 3, and the powder is By doubling the sealing effect, the amount of leakage from the contact area between the outer end surface of the blade and the inner surface of the casing, excluding the amount of displacement air due to the space volume between the blades of the rotor 34, is almost the same even under high differential pressure conditions. It has been demonstrated that the amount is negligible.

Next, a drop tube 4 is connected to the discharge port 33 of the rotary feeder 3, and high-pressure air is jetted from the lower blow nozzle 6 to the multiphase feed pipe 7, and the group of transported objects is shaped like a plug. When the plugs are transported, they move to the downstream side of the transport path system 8 while forming an air layer between the plugs.

At this time, the jet of compressed air collides with the plug surface, and a part of the repulsed jet energy flows back up to the upper part of the falling discharge pipe 4. The rise in pressure in the same area as the jet rises serves to lift the rotor 34 as described above, and also serves as a source of power to prevent leakage. This assists in the stirring effect and helps to stabilize the stable supply and discharge of powder and granular material from the discharge port 33 of the rotary feeder 3.

Embodiment 2 Another applied embodiment of the present invention will be described with reference to FIG.

Here, we will introduce the blast furnace of a steelworks (furnace pressure: 3 to 6 kg/
We will explain the case where it is put to practical use as a pneumatic transport device that feeds an equal amount of pulverized coal for fuel to one or several dozen combustion ports into a high-pressure combustion furnace such as 2 ^cm2 ).

The pulverized fuel coal of coking coal is transported from a crusher or a storage tank and put into a silo or hopper 9, and is fed in a fixed amount downward by a conventional low-pressure rotary feeder 10, which is connected via a flexible pipe 11. The fuel is discharged and dropped into a weighing storage tank 12 equipped with an appropriate weighing mechanism 13, and the total amount of combustion is carried out in a weighing operation.

Below the weighing storage tank 12, there are the above-mentioned distribution hopper 1a, chute tube 2, high-pressure type rotary feeder 3, drop tube 4, and multiphase feed pipe in a number corresponding to the combustion holes of the combustion furnace to be transported. 7 are arranged in a connected manner.

By connecting each device to a transportation pipeline system 8 that is independently piped for exclusive use, a fixed amount can be continuously fed to the combustion port nozzle 14 provided on the wall of the high-pressure combustion furnace 15, and a predetermined amount of pulverized coal can be delivered. Continuous combustion furnace 15
Even combustion occurs through internal injection.

In this case, the injection into the high-pressure combustion furnace 15 is preferably carried out at a high speed of 25 to 30 m/s or more from the viewpoint of preventing backfire, and since a predetermined amount is required as the carrier fluid and oxygen for combustion, conventionally Since it is often transported at low concentrations, and the pressure loss in the transport pipe system 8 is about 1 to 2 Kg/cm ² , the pressure loss of 3 to 7 Kg/cm ² , which is the furnace internal pressure plus this pipe pressure loss, is is needed.

In this invention, a rotary leaf feeder can be used as an air source using a compressor capable of supplying the high-pressure air, so with the above-described configuration, high-pressure air can be continuously supplied as a conveying energy source, and various powder and granular materials can be Steady and stable pneumatic transport can be established.

Effects of the Invention In this invention, since the rotor is provided eccentrically with respect to the housing, the rotor is pushed by a predetermined pressure difference between the inflow port side and the discharge port side in the pneumatic transportation device, and the rotor is moved toward the inflow port. The rotor blade rotates in a state in which it contacts or is on the verge of contact, that is, in a state in which the clearance at the tip of the rotor blade is close to zero, thereby preventing pressure leaks in that part.

Furthermore, the effectiveness of the material seal in the chute tube, the effect of stirring mixture to assist quantitative discharge in the falling tube, and the effect of forming appropriate plugs of a certain length and at regular intervals in the multiphase feed pipe, together with the With low-speed, high-concentration transportation using air as an air source,
Enables continuous quantitative supply transportation.

In addition, in the handling process of various new micronized materials and composite materials in recent years, particles are transferred at a low speed as much as possible to prevent particle breakage, deterioration, decrease in homogeneity, and contamination. There is a growing demand for a low-speed, high-concentration pneumatic transportation system that focuses on reducing the chance of frictional contact between walls, and this can more than meet this demand.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a compressed air device according to the present invention, and FIGS. 2a and 2b are longitudinal sectional views of the main parts of the same device. FIGS. 3a and 3b are a front view and a side view of the rotor portion of the rotary feeder according to the present invention. FIG. 4 is also a front explanatory view of the rotor section. FIGS. 5a and 5b are a longitudinal sectional front view and a side view of the rotary feeder according to the present invention. FIG. 6 is a schematic diagram of an embodiment in which the pneumatic transport device according to the present invention is applied to a high-pressure combustion furnace. FIGS. 7 and 8 are schematic illustrations of conventional transportation methods. 1... hopper, 2... chute tube, 3... rotary feeder, 4... falling tube, 5... different diameter tube,
6...Blow nozzle. 7... Multiphase feed pipe, 8...
Transport pipeline system, 31... casing, 32... inlet, 33... outlet, 34... rotor, 35...
... Drive shaft, 36 ... Shaft hole, 37, 38 ... Communication hole, 15 ... High pressure combustion furnace.

Claims (1)

[Claims] 1 A rotor is housed in a cylindrical casing with vertical openings, with a rotating shaft horizontally and eccentrically supported, and the tips of the rotor blades are connected to the inlet or A multiphase feed pipe with a low-pressure or atmosphere-released hopper connected to the inlet of a rotary feeder that can come into contact with the inner peripheral surface of the casing around the outlet, and a blow nozzle installed at the outlet, and its tip. A communication passage is provided in the casing to introduce the rotor chamber pressure on the return side to the rotor chamber filled with powder and granules.
A pressure-feeding air transport device characterized by being connected to a compressor capable of producing compressed air of 1.0Kg/cm ² or more.