JP2001171824A - Belt conveyor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a belt conveyor device increasing removal rate (recovery rate) of residual adhesion granules after carrying out the granules. SOLUTION: This belt conveyor device is provided with an endless conveyer belt 16 wound around a table pulley 12 and a head pulley 14 and used for conveying the granules. An air nozzle 38 for an air blow device 36 is arranged in the rear side of a conveying materials discharge position of the head pulley 14. An air jetting face jetting air at 30-120 deg. relative to a face in the conveyance direction of the conveyer belt can be formed therein.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt conveyor device in which an endless transport belt is wound between a tail pulley and a head pulley, and is used for transporting powdery and granular materials. In particular, the present invention relates to an invention of a belt conveyor device suitable for removing powder and particles attached to a conveyor belt.

Here, a description will be given mainly by taking as an example the transport of foundry sand as the transport of powder and granules. Examples of the powder and granular material transport to which the present invention can be applied include inorganic powder and granular materials such as iron / steel / non-ferrous metal raw material, cement raw material, ready-mixed concrete, lime raw material, fertilizer raw material, quarry raw material, ceramic raw material, coke raw material, feed, processing Organic powder and granular materials such as foods and papermaking raw materials can be transported.

[0003]

2. Description of the Related Art As one means of transporting powder or granular material such as foundry sand,
There is a belt conveyor device.

As shown in FIG. 1, the belt conveyor device has a basic configuration in which an endless transport belt 16 is wound between a tail pulley 12 and a head pulley 14.

Here, the forward path (transport path) of the transport belt 16
A required number of carrier rollers 18 are provided at the lower surface position, and a required number of return rollers 20 are provided at the lower surface position of the return path. In addition, the snap pulley 2
2. A tension roller (also used as a head pulley), a bend pulley, and the like are appropriately disposed. As shown in FIG. 2, the carrier roller 18 has a belt conveying surface with a trough cross section and prevents the belt from bending. The return roller 20 has an effect of preventing the belt from bending in addition to the belt conveyance. In the illustrated example, the head pulley 14 also serves as a driving pulley, but a driving pulley may be separately provided.

In FIG. 1, reference numeral 24 denotes a loading hopper (input hopper), and reference numeral 26 denotes a discharge chute (discharge chute) provided with a dust collection duct 26a. In FIG. 2, 28 is a roller base, and 30 and 32 are brackets for a carrier roller and a return roller, respectively.

The transport belt 16 uses a core formed of canvas impregnated with rubber glue and further protected by rubber having heat resistance, abrasion resistance and the like. Here, the canvas used is made of polyamide fiber or polyester fiber having high strength and low elongation.

When the molding sand is conveyed by the above-mentioned belt conveyor device, the molding sand adheres and remains on the conveyance belt after the discharge of the granular material. The reason is as follows.

[0009] Foundry sand has high activity due to residual heat, and also contains moisture, and is liable to aggregate and adhere to the belt conveying surface.

[0010] Also, fine powder of 270 mesh under (Tyler standard sieve) (53 μm or less) called a bread causes friction between the molding sand and the belt surface due to vibrations during transportation, and generates static electricity. Let it.

Furthermore, when a conveyor belt made of rubber or the like is used for a long time, cracks (including cracks) and the like due to rubber deterioration occur on the belt conveyor surface, and molding sand penetrates to increase the residual adhesion amount.

That is, the roughness of the belt surface caused by the drop impact and abrasion of the molding sand, the pulling of the conveyor belt around the pulley and the trough bending promotes the crack generation and growth due to the rubber deterioration. Continued use may cause further damage to the conveyor belt.

[0013]

For this reason, the remaining deposits of molding sand are usually scraped and removed by arranging a scraper 34 made of a rubber plate as shown in FIG. 1, but the removability is low.

In view of the above, it is an object of the present invention to provide a belt conveyor device capable of increasing the removal rate (recovery rate) of residual adhered powder particles after carrying out the powder particles.

[0015]

The belt conveyor device of the present invention solves the above-mentioned problems by the following constitution.

An endless transport belt is wound between the tail pulley and the head pulley, and in a belt conveyor device used for transporting the granular material, an air nozzle of an air blow device is provided at a position in a transport direction of a transported material discharge position of the head pulley. 30 to the conveying direction surface of the conveying belt
This is a configuration in which an air jet surface that is jetted at 120 ° can be formed.

In the above structure, the air jetting surface may be formed on the winding and bending surface of the head pulley, and further, a scraper may be disposed on one or both of the front and rear sides of the conveying belt in the conveying direction of the air jetting surface. But
This is desirable because the removal rate of the attached powder particles increases.

The belt conveyor of the present invention is desirably applied to the transportation of foundry sand because the effect is remarkable.

The method for removing particles attached to a conveyor belt in a belt conveyor according to the present invention is a method for removing particles adhered to a conveyor belt after discharging particles in a belt conveyor used for conveying particles. And injecting air at an angle of 30 to 120 ° with respect to the surface of the conveyance belt in the conveyance direction.

[0020] In the above structure, the air injection is performed on the winding bent surface of the head pulley of the conveyor belt, and further, the adhesion reducing agent is applied to the conveyor belt, and / or Performing scraping and removing in a step before and / or after the air injection increases the efficiency of removing residual adhered particles, respectively.

The effect of applying the adhesion reducing agent by spraying becomes remarkable. Further, it is possible to spray the belt simultaneously with the air by using the spray pressure of the air spray.
The device can be simplified.

The effect of the method for removing powder particles attached to a conveyor belt in the belt conveyor apparatus of the present invention is remarkably effective when applied to casting sand transportation.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The description of the already described portions is denoted by the same reference numeral, and all or part of the description is omitted.

As described above, the belt conveyor has a basic structure in which an endless transport belt 16 is wound between a tail pulley 12 and a head pulley 14.

Here, a required number of carrier rollers 18 are provided at the lower position of the forward path (conveying path) of the conveying belt, and a required number of return rollers 20 are provided at the lower position of the returning path.

In the above-mentioned conventional configuration, the belt conveyor device of the present embodiment is provided with an air nozzle 38 forming an air blow device 36 at a position immediately after the discharge of the conveyed material of the head pulley 14, that is, behind the discharge chute 26. is there.
The air nozzle 38 is capable of forming an air jetting surface at which the air is jetted at 30 to 120 °, preferably 30 to 90 ° with respect to the conveying direction surface of the conveying belt 16. here,
If it is less than 30 °, the wind pressure (impact) applied to the belt surface in the transport direction is weakened, and it is difficult to obtain a sufficient effect of removing powder and granules (casting sand). On the other hand, when the angle exceeds 120 °, the wind direction becomes parallel to the belt conveyance direction, the wind pressure is weakened, and the granular material removal rate is reduced.

In the illustrated example, the air nozzle 38 is connected to an existing air pipe, but may be directly connected to a single blower.

In the illustrated example, the air jetting surface is formed on the winding and bending surface of the head pulley 14 from the viewpoint of the efficiency of removing the granular material. The belt reversing surface side such as the rear side may be used. That is, as shown by the two-dot chain line, the air nozzle 38
A may be arranged. Also, the scraper 34 is not inevitable.

The position of the air nozzle 38 may be either one of the front side and the rear side of the scraper 34, or one of the two.

In the air injection, a plurality of air outlets (air injection portions) 38a are formed at regular intervals, and with some intervals being changed as necessary. For example, an air nozzle 38 as shown in FIG.
(38A).

The interval between the outlets 38a is 5 to 100 mm,
Preferably, it is 10 to 50 mm. If it is less than 5 mm, the air blown out from the outlet 38a interferes with each other to reduce the effect of air injection, and the number of outlets increases, so that the air consumption becomes relatively large and energy loss occurs. If it is more than 100 mm, the air does not hit and there is a section of removal leakage.

The distance between the belt surface and the outlet 38a is 5 to 100 mm, preferably 10 to 50 mm. 5mm
In the following, there is a danger of contact with the running belt.
This is because the impact of air injection is attenuated when the thickness is greater than 00 mm.

The air injection amount per outlet is 2 to
100 L / min, preferably 5 to 50 L / min.
At less than 2L / min, the impact of removing sand is difficult to obtain,
Conversely, if it is 100 L / min or more, the air consumption increases and it is wasteful.

The hollow cross section of the air nozzle is a funnel-shaped (tapered tapered) nozzle 38 as shown in FIG. 3 (1) where wind pressure can be easily obtained, but a straight type as shown in FIG. 3 (2). The nozzle 38A may have any shape, such as an inverted tapered shape or a hollow bulged Tyco shape.

Further, in order to more efficiently remove the adhered particles, the adhesion reducing agent may be applied to the conveying surface of the conveyor belt simultaneously with the air jet or at a position after the adhered particles are removed. desirable. When the adhering powder (casting sand) is wet sand containing water (wet sand) or resin-coated sand, it has a strong adhesion to the belt conveyance surface, so it is difficult to remove it by air blow alone, reducing adhesion. Application of the agent is inevitable.

The method of applying the adhesion reducing agent is usually spray coating, but may be contact coating (including roller coating and dip coating).

FIG. 4 shows an example of the nozzle 38B which simultaneously performs the injection of the adhesion reducing agent with the air.

The nozzle 38B has a double pipe structure, has an air supply pipe 40 on the center side, and has an adhesion reducing agent filling section 44 formed by a jacket 42 on the outside. A plurality of protruding air ejection portions 38b are provided along a generatrix (meridian) of the air supply pipe 40. Then, the air ejection part 38
An adhesive reducing agent jetting part 42a is formed with a gap around the front end of b and the peripheral surface of the jacket 42. That is, the adhesion reducing agent can be ejected from the ejection portion 42a by the ejector action at the time of air ejection.

The adhesion reducing agent penetrates between the belt surface and the conveyed material (casting sand (granules)) to avoid direct contact between the conveyed belt surface and the conveyed material, and the belt surface is This makes it easier for the transported object to fall when it is turned over at a position. In addition, surface roughness caused by belt deterioration, horizontal wrinkles due to bending,
Adhesion-reducing agent enters cracks created by side guards or slip prevention devices to prevent falling items,
There is also an effect of preventing the attached powder particles from infiltrating into these transparent areas.

The form of the adhesion reducing agent may be in the form of a liquid or a powder, but preferably a powder is used. More preferably, a powdery adhesion reducing agent having lubricity and water repellency is used. This is because, in the case of a liquid, the drying of the dispersion medium or the stickiness of the dispersoid may impair the falling off of the powdery deposit.

Examples of the type of the adhesion reducing agent include inorganic lubricants such as talc, mica, titanium oxide, graphite, and boron nitride;
Organic lubricant such as high molecular weight polyethylene, metallic soap (calcium, magnesium, aluminum stearate, etc.), higher fatty acid bisamide, high melting point wax, silicon powder, etc .; In addition, it can be appropriately selected and used according to the characteristics of the adhered powder.

The coating amount of the conveying belt surface, the type of adhesion-reducing agent, the belt surface conditions, and varies depending on the kind of the transfer material, on a solids, usually, 0.01 to 10 g / m ^2, preferably 1 to 5 g / m ² .

In the above embodiment, the casting sand (conveyed material) S is dropped from the charging hopper 24 and the conveyed material (casting sand) S is discharged into the discharge chute 26 at the end of the conveying path of the conveying belt 16 (at the position of the head pulley 14). Although it is configured to drop, various configurations can be adopted without departing from the scope of the claims of the present invention. To remove powdery deposits containing water, in addition to air jetting, spray an adhesion-reducing agent, and use a drying device (dehumidified air for air jetting) before scraping and removing. It is possible to more effectively remove the adhered substance by adopting a configuration in which an attachment or the like is installed, and further by installing a vibration device.

Next, a case where the molding sand is transported using the belt conveyor device of the above embodiment will be described.

The foundry sand poured into the charging hopper 24 falls onto the transport surface of the transport belt 16. By operating the belt conveyor, the conveyor belt 16 conveys the foundry sand S to the position of the head pulley 14 and discharges the chute S.
Discharge into 6. Even after the foundry sand is discharged, since the foundry sand has heat and moisture, it adheres to the conveyor belt and remains as adhered powder. In this state, air is injected from the air nozzle 38 at an angle of 30 to 120 ° with respect to the plane in the air transport direction to form an air injection surface. Due to the air injection, the attached foundry sand falls into the discharge chute 26. At this time, it is desirable to simultaneously spray the adhesiveness reducing agent with the air spray using the nozzle 38B as shown in FIG.

It is presumed that the reason for this is that, by the air injection, the adhered foundry sand is easily separated from the conveying surface, and the air has an effect of invading and scraping out cracks generated on the belt surface.

When the molding sand adhesion amount is large, after air injection,
It is desirable to scrape off the adhering foundry sand which has become easily detached by the scraper 34, and then to perform the air injection again.

In the above, since the air ejection surface is formed on the winding and bending surface of the head pulley,
Cracks and the like on the conveyor belt are opened, and the removability of the attached molding sand by air injection is further increased.

In the above embodiment, the air injection is performed on the head pulley side. However, it does not matter that the foundry sand falls and accumulates between the head pulley and the tail pulley.
If the purpose is to reduce the amount of residual foundry sand adhering to the conveyor belt and to prevent the conveyor belt from deteriorating, etc., between the head pulley and the tail pulley (return surface of the conveyor belt)
It is possible to perform air injection at an arbitrary position in.

[0050]

Test Examples Hereinafter, test examples performed to confirm the effects of the present invention will be described.

<Test Example 1> Belt width / length 600 mm × 20 m Belt speed 70 m / min Conveyed product Foundry sand, fresh sand recovered sand Air nozzle shape Figure 3 (1) Air outlet arrangement 30 mm Air injection amount 40 L / min (Air The distance from the belt was 15 mm. The angle with respect to the belt surface was 80 °. With the above configuration, the belt conveyor was operated for 16 hours, and the degree of removal of powdery deposits was evaluated.

As a result, comparing the amount of sand dropped and deposited on the floor surface without falling into the chute from the surface of the belt portion, the amount of deposited molding sand was removed using only the scraper. In contrast to 6 kg, the amount of deposition was reduced to 2.3 kg when air jetting was also used. This indicates that the removal efficiency is better with air injection alone than with scrapers alone.

<Test Example 2> In order to compare the effect of air injection due to the difference in the shape of the air outlet, the hollow cross section of the air nozzle was made into a funnel shape (FIG. 3 (1)) and a straight type (FIG. 3 (1)). 2) The magnitude of the load applied to the belt portion surface was measured under the following conditions using the above-mentioned method.

Tip diameter 1.2 mmφ Distance from outlet 20 mm Air injection amount 33 L / min As a result, the load (air injection impact) applied to the area of a circle having a diameter of 10 mm is 127 mN (13.0 g) in the funnel type.
f), which was 109 mN (11.1 gf) in a straight type.

<Test Example 3> The effect of removing the adhered particles by the type of the adhesion reducing agent was indirectly evaluated.

Each of the adhesion reducing agents shown in Table 1 was applied (applied amount: 1 g / m ² ) to cut pieces (30 cm square) from a belt conveyor for conveying foundry sand to obtain test pieces. 10 g of foundry sand (fresh sand) was placed on each test piece so as to be uniform, and allowed to stand for 24 hours. Thereafter, the test piece was inverted, and the adhesion of the foundry sand was examined.

As the foundry sand (fresh sand), kneading sand,
The recovered sand after the dispersion was used.

From the results shown in Table 1, it can be seen that the powdery adhesion-reducing agent is surely superior in the removing effect to the liquid adhesion-reducing agent.

[0059]

[Table 1]

Example 4 Using a powdery adhesion-reducing agent, the effect of removing adhering particles due to differences in the humidity of molding sand was indirectly evaluated.

In the same manner as in Example 3, each test piece (30 cm square) was prepared by applying each of the adhesion reducing agents shown in Table 2 to the cut pieces from the belt conveyor (the same coating amount). A casting sand (dry sand: 10 g, wet sand: 10 g) was placed on each test piece, and a load was applied (9.8 × 10 ⁵ Pa (10 kg / cm ² ) × 10 seconds). As the foundry sand, dry recovered sand (fresh sand) and wet raw sand containing 3% water in the dried recovered sand were used.

The following can be seen from Table 2 showing the results.

The dry sand and wet sand have different effects of removing raw sand depending on the type of the adhesion reducing agent. (However, magnesium stearate is effective for all.) In dry sand, graphite and magnesium stearate are used. In wet sand, magnesium stearate, calcium stearate, and silicon powder are used. Was good. In other words, a lubricating and water-repellent metal soap (particularly an alkaline earth metal salt) adhesion-reducing agent is effective for wet sand.

[0064]

[Table 2]

<Example 5> Belt width 600 mm Belt speed 120 m / min Conveyed material Raw sand (dry green sand, wet green sand) Distance between nozzle and belt 20 mm Air outlet arrangement 30 mm Air nozzle shape Fig. 3 (1) Adhesion Adhesion reducing agent 50% graphite, 50% calcium stearate Adhesion reducing agent coating amount 1 g / min In the above configuration, the belt conveyor was operated for 8 hours.
The adhesiveness reducing agent was applied to the belt surface simultaneously with the air by using the air injection pressure. Then, the air injection amount from the nozzle was adjusted, and the degree of removal of powdery deposits was examined.

Table 3 shows the air injection amount (per air outlet) required to remove powdery deposits almost completely.

The results shown in Table 3 indicate the following.

If the adhesion reducing agent is injected, the molding sand can be almost completely removed with a lean air injection amount (usually 40 L / min or less). However, in the case of using only the air blow, when the fresh green sand or the wet raw sand is conveyed by the wet belt, the molding sand cannot be completely removed.

[0069]

[Table 3]

[0070]

Operation and effect of the present invention
A configuration in which powdery deposits on the belt surface of the belt conveyor are removed by air injection, compared with a scraper, the removal rate (recovery rate) of residual attached particulates after the transport of particulates
Can be increased.

Therefore, the loss of the conveyed material of the granular material is smaller, and a suitable working environment can be maintained. In addition, the burden of the removal operation is reduced, and labor (reduced man-hours) can be reduced. Further, the operation rate of the belt conveyor device does not decrease.

Further, at the time of air jetting, in addition to the air jetting, it is also possible to apply an adhesion reducing agent (particularly powdery) to the conveyor belt, because it is possible to apply powdery deposits on the belt surface of the belt conveyor. Can be more completely removed. The application position of the adhesion reducing agent is not particularly limited, but performing the operation simultaneously with the air injection leads to an increase in working efficiency.

Although it does not affect the inventiveness of the present invention, an alkaline solution or a cationic surfactant (metal soap is an anionic interface) is applied to the surface of the conveyor belt in order to prevent powder particles from adhering to the conveyor belt in the belt conveyor device. Activator) is disclosed in JP-A-10-2183.
No. 41 discloses this.

[Brief description of the drawings]

FIG. 1 is a model diagram of a belt conveyance device showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a perspective view and a cross-sectional view showing a form of an air nozzle used in the present invention.

FIG. 4 is a cross-sectional view showing one embodiment of an air nozzle used when the adhesion reducing agent is injected simultaneously with the air injection in the present invention.

[Explanation of symbols]

 12 Tail Pulley 14 Head Pulley 16 Conveyor Belt 34 Scraper 36 Air Injector 38, 38A, 38B Air Nozzle 40 Air Supply Pipe 42 Jacket 38a, 38b Air Injection Part 42a Reducing Agent Injection Part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takae Nagata 1-16-1, Hosoki-cho, Kasugai-shi, Aichi Prefecture Tetranai Co., Ltd. (72) Inventor Haruyuki Doi 1-Toyota-cho, Toyota-shi, Aichi Prefecture Toyota Motor Corporation (72) Inventor Masao Uie 45-3 Sunsaku, Nishitakayama-cho, Kasugai-shi, Aichi

Claims (12)

[Claims] An endless transport belt is wound between a tail pulley and a head pulley, and in a belt conveyor device used for transporting powdery and granular materials, an air nozzle of an air blow device is provided behind a transported material discharge position of the head pulley. A belt conveyor device, wherein an air jetting surface is formed such that an air jetting surface is jetted at 30 to 120 ° with respect to a conveying direction surface of the conveying belt. 2. The belt conveyor device according to claim 1, wherein the air ejection surface of the transport belt is formed as a winding surface of a tail pulley. 3. The belt conveyor device according to claim 1, wherein a scraper is disposed on one or both of a front side and a rear side of the conveying belt in the conveying direction of the air ejection surface. 4. The belt conveyor device according to claim 1, wherein the powdery or granular material is foundry sand. 5. A method for removing particles adhered to a conveyor belt after discharging particles in a belt conveyor device used for conveying the particles, the method comprising: A method for removing powder particles attached to a conveyor belt in a belt conveyor device, wherein air is injected at 30 to 120 degrees. 6. The method according to claim 5, wherein the air jetting is performed on a winding and bending surface of a head pulley of the conveyor belt. 7. The method according to claim 5, wherein an adhesion reducing agent is applied to the conveyor belt in addition to the air injection. . 8. The method according to claim 7, wherein the adhesion reducing agent is a powder. 9. The method according to claim 1, wherein the application of the adhesion reducing agent is performed by spraying, and the adhesion reducing agent is sprayed onto the belt surface simultaneously with air using the injection pressure of the air injection. A method for removing powder particles attached to a conveyor belt in the belt conveyor device according to claim 8. 10. The belt conveyor device according to claim 7, wherein, in addition to the air jetting and the application of the adhesion reducing agent, scraping and removing are performed in a step before and / or after the air jetting. A method for removing powder particles attached to the conveyor belt. 11. The powder material adhered to a conveyor belt in a belt conveyor device according to claim 5, wherein, in addition to said air injection, scraping and removing are performed in a step before and / or after the air injection. Removal method. 12. The method according to claim 5, wherein said powdery granules are foundry sands.