JPS5952130B2 - Flaky sulfur dust generation prevention method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing the generation of flaky sulfur dust, which can be particularly effectively applied when flaky sulfur is conveyed to the bed of a truck by a belt conveyor.

Conventionally, when flaky sulfur was shipped onto a truck using a truck shipping belt conveyor, there was a drop of about 1 meter from the exit of the conveyor casing to the truck bed, so the sulfur could fall onto the truck bed while falling. The impact generated an extremely large amount of dust, which was scattered in all directions, creating a situation where people could not approach the work site without wearing dust-proof goggles and masks, posing a serious occupational health problem.

As a method for preventing the generation of such dust, there is a suction method using a blower, which has been researched in steel works, etc., and this blower suction method is also used to prevent the generation of flaky sulfur dust as described above. It is being

The blower suction method is a method in which the generated dust is sucked in with a blower, separated and collected using a bag filter, etc., and is mainly used on belt conveyors and packet elevators to prevent the generation of flaky sulfur dust. It is used as a countermeasure against dust in sealed structures such as shipping ports, etc. Even if a hood is installed especially in areas open to the atmosphere such as shipping ports, there is a limit to the dust suction ability of the blower, and it is difficult to effectively remove dust. It is no exaggeration to say that there is currently no solution to preventing dust at the shipping port, as it cannot be expected to prevent it from occurring.

Furthermore, the conventional blower suction method naturally requires the installation of a suction duct, blower, bag filter, etc., which results in extremely high installation costs and requires dust collection work.
The problem is that the driving operation becomes extremely complicated.

In addition to the above-mentioned prevention of dust generation, when working with powder, it is also required to prevent dust explosions and fires within the casing.

For this purpose, nitrogen (N2) gas is blown into the conveyor casing to reduce oxygen (02%) to the limit of dust explosion (9%).
It was necessary to manage it so that it was below 7%.

More specifically, there is a risk of dust explosion in the production, storage, and shipping facilities of flaky sulfur, and to prevent this, inert gas is blown into the equipment, and the explosion limit is 0.2% (9.3% when N2 gas is used). %, or 12% when using CO2 gas
) Below is the management schedule.

However, the conventional blower suction method has the drawback that the inert gas is also sucked by the blower, resulting in an enormous amount of inert gas being required and an extremely high operating cost.

Furthermore, as a technology to prevent dust generation, water is sprayed onto the conveyed materials, and in order to sufficiently moisten the conveyed materials and prevent the generation of dust, a large number of small hole nozzles are installed on the discharge side of the conveyor system to spray pressurized water in the form of water droplets. A method of atomizing the material has also been proposed, but although this dust generation prevention method can prevent the generation of dust, the conveyed material itself contains a large amount of moisture, which makes it difficult to use the material in the future. It was extremely difficult to handle, and if it was to be constructed, it was necessary to install an additional drying process to dry the material.

Accordingly, the main object of the present invention is to provide a novel method for preventing the generation of flaky sulfur dust, which overcomes the drawbacks of conventional methods and devices for preventing dust generation.

An object of the present invention is to provide a method for preventing the generation of flaky sulfur dust, which can prevent the generation of dust while preventing dust explosions.

The object of the invention is to avoid substantially changing the moisture content of the applied material, thus making the subsequent handling of the material difficult and without requiring any subsequent extra steps such as drying steps. It is an object of the present invention to provide a method for preventing the generation of unnecessary flaky sulfur dust.

An object of the present invention is to provide a method for preventing the generation of flaky sulfur dust, which can prevent the generation of dust while preventing dust explosions by using an extremely small amount of inert gas for preventing dust explosions.

Another object of the present invention is to provide a method for preventing the generation of flaky sulfur dust, which is easy to operate and inexpensive to install.

The above aspects are completely achieved by the present invention, which is constructed by bringing heated steam into contact with dust generated in facilities for producing, storing and shipping flake sulfur to such an extent that the moisture content of the material does not change. Ru.

According to the present invention, sulfur and steam are brought into contact, and blowing the steam into a predetermined equipment increases the humidity within the equipment and lowers the humidity within the equipment, thereby suppressing the generation of dust itself. It also acts to eliminate the possibility of dust explosions.

In addition, the humidifying effect of steam inside the equipment also has an anti-static effect, contributing to improved safety.

Furthermore, the humidification effect of the heated steam inside the equipment does not increase the moisture content of the product, that is, the flaky sulfur.

Next, the method for preventing the generation of flaky sulfur dust according to the present invention will be explained with reference to drawings showing an apparatus for implementing the method.

With reference to FIGS. 1 and 2, it will be appreciated that the present invention is embodied in a shipping facility for shipping sulfur flakes onto the bed of a truck using a belt conveyor. .

The shipping equipment includes a transport device 1 for transporting flaky sulfur M from production equipment and/or storage equipment (not shown) to a loading platform T of a truck, and a frame 5 that supports the transport device.
and.

The conveying device 1 is usually used in the industry 5,
It can be of a belt conveyor type that includes a conveyor belt 2 and a pulley 3.

A dust generation prevention technique 10 for carrying out the method according to the present invention is installed at the sulfur discharge end of the shipping equipment, that is, at the right end where the pulley 3 in FIGS. 5.

The dust generation prevention device 10 includes a casing 12 surrounding the discharge end of the conveying device 1, and a shipping port 14 for powder, for example, flaky sulfur M, is provided at the lower end.

Inside the casing 12, a first baffle plate 16 is provided tilting downward to receive the sulfur M that is conveyed by the conveyor belt 2, goes around the pulley 3 at the discharge end, and naturally falls downward. .

The sulfur θM that has fallen onto the first baffle plate 16 is
It slides down while being guided downward through a path defined by the baffle plate 16 and a guide plate 18, 20 provided opposite to the upper surface of the first baffle plate 16.

As shown in FIG. 3, the guide plates 18 and 20 have a width W2 at the lower end, that is, a width at the outlet end of the sulfur M, and a width at the upper end in order to limit the traveling width of the falling sulfur M. It is attached so that it is smaller than W1, that is, the size of the inlet end of sulfur M.

Rubber plates 22 and 24 are provided at the lower end of the first baffle plate 16 so that the lower end edges of the guide plates 18 and 20 and the inner 'θ side edges 26 and 28 are approximately aligned.

The other ends of the rubber plates 22 and 24, that is, the free lower ends, are
This also comes into contact with the upper surface of the second baffle plate 30, which is arranged to obstruct the path of the sulfur M that slopes downward inside the casing 12 and slides down the first baffle plate 16. There is.

Therefore, the lower edge of the first baffle plate 16, the guide plate 18.
A drop opening 21 (FIG. 3) for the sulfur M into the second baffle plate 30 is defined by the lower edge of the rubber plate 20, the inner edge of the rubber plate 22, 24, and the upper surface of the second baffle plate 30.

Rubber plates 22 and 2 provided at the tip of the first baffle plate 16
4, when sulfur fragments and powdered sulfur that have exceeded the guide plate 18.20 accumulate on the rubber plate 22.24 due to long-term use, the rubber plate bends due to the weight of the sulfur and the second
It is separated from the baffle plate 30 and serves to cause the sulfur on it to fall downward.

As shown in FIG. 2, the second baffle plate 30 has an upper end attached to the inner wall of the casing 12, extends diagonally downward, and comes into contact with the tip edge of the rubber plate 22, 24, Furthermore, it protrudes diagonally downward by a predetermined distance.

Therefore, the sulfur M that has slid down the first baffle plate 16 and fallen through the drop port 21 falls onto the upper surface of the second baffle plate 30, and then slides downward along the second baffle plate 30.

When the sulfur M on the second baffle plate 30 reaches the lower end of the second baffle plate 30, it then falls onto a third baffle plate 32 provided apart from the lower end of the second baffle plate.

The third baffle plate 32 is also provided in the casing 12 so as to be inclined downward, and guides the sulfur M that has fallen onto the third baffle plate 32 to the shipping port 14 of the casing 12.

Sulfur M released from the third baffle plate 32 to the shipping port 14 is released from the third baffle plate 3 before being released from the shipping port 14.
Exit plates 34 and 36 provided between 2 and the shipping port 14
Forced to fall upwards.

Outlet plates 34 and 36 are preferably rubber plates, and if sulfur is not on the outlet plates, as illustrated in FIG.
When sulfur is dropped onto the outlet plates 34 and 36, the rubber plates bend due to the weight of the sulfur, causing the sulfur to fall into the shipping port 14. Constructed as possible.

A partition plate 38 is provided between the tip of the first baffle plate 16 and the tip of the third baffle plate 32.

Therefore, a first baffle plate 16 is further provided inside the casing 12.
, a first chamber 40 surrounded by a second baffle plate 30 and a partition plate 38; a second baffle plate 30, a casing 12, a third
A second chamber 42 is defined, surrounded by the shield plate 32 and outlet plates 34 and 36.

A spray nozzle 44 is provided in the first chamber 40 and the second chamber 42.
, 46 and 48, 50 are provided, respectively.

At this time, the injection ports of the spray nozzles 44 and 46 are
The spray nozzle 48 is placed so as to face the baffle plate 30.
and 50 are arranged to face the third baffle plate 32.

Furthermore, the spray nozzles can be of any size, shape, and number as desired; for example, the arrangement of the spray nozzles may be
As schematically illustrated in the figure, there are three upper spray nozzles 44 in the first chamber 40, and the remaining spray nozzles 46, 48, 5 in the lower stage of the first chamber 40 and the upper and lower spray nozzles 42 in the second chamber 42.
Five 0's may be provided.

Furthermore, to explain the above structure specifically, the first, second and third baffle plates 16, 30 and 32 and the partition plate 38 are preferably made of stainless steel plates (for example, 5US304
), and the angles of the parts where sulfur may get on, that is, baffle plates, partition plates, casings, and outlet plates, are all 45 degrees because the angle of repose of sulfur is considered to be 35 to 45 degrees. It is preferable to set it as above.

In particular in the example α=β=45° and γ=60°
was configured.

This angle is not critical and can vary depending on the type of material being handled.

Further, the size of the drop opening 21 was 400 x 150 mm, and the spray nozzles were arranged at a distance of 150 mm from the baffle plate and at a pitch of 110 mm.

A preferred spray nozzle is TYPEI/2 manufactured by Arakura Kogyo.
It was Ex 225, material 5US304, and wide-angle circular full-surface injection 172B.

This nozzle generates very low static electricity due to steam jetting (maximum 400V at source pressure 6kg/cm2G)
It is superior in terms of safety compared to a drilled hole (3 mm' hole, 60,000 V or more when the original pressure is 6 kg/cm2G), and wide-angle injection of steam is also possible.

The apparatus is also provided with means for returning sulfur not received by the first baffle plate 16 to the shipping port 14.

A rubber plate 52 is provided between the partition plate 38 and the casing 12, with one end fixed to the partition plate 38 and the other free end abutting against the inner wall of the casing 12.

The two sulfur M that are not received by the first baffle plate 16 are collected and accumulated on the rubber plate 52 by the partition plate 38 or the inner wall of the casing 12.

When the accumulated sulfur M reaches a predetermined amount, the rubber plate bends,
The contact state between the rubber plate 52 and the inner wall of the casing 12 is broken, a gap is created between them, and the accumulated sulfur M flows along the inner wall of the casing 12 through the gap. It slides down the passage formed by the baffle plates and onto the exit plates 34 and 36.

The sulfur discharged from the outlet plates 34 and 36 to the shipping port 14 falls onto the truck bed T located below the shipping port 14 and is received.

Further, an inert gas such as N2 gas is flowed into the casing 12 to prevent explosion of dust.

Next, the operation mode of the above device will be explained.

The flaky sulfur M transported by the transport device 1 goes around the discharge end pulley 3 and falls onto the first baffle plate 16.

The sulfur M slides down on the first baffle plate 16 and falls onto the second baffle plate 30 through the drop opening 21 with its width being restricted to 400 mm by the guide plate 20.

The sulfur M on the second baffle plate 30 slides down on the baffle plate and falls onto the third baffle plate 32.

The third baffle plate 32 guides the sulfur M to the outlet plates 34, 36, through which the sulfur M is discharged into the shipping port 14 and then falls onto the 1-rack loading platform T. .

When the sulfur M slides down as described above, steam is injected through the spray nozzles 44, 46 and 48° 50 provided in the first chamber 40 and the second chamber 42.

Therefore, most or all of the sulfur M that slides down is
The chamber 40 and the second chamber 42 are humidified by steam, and dust is completely prevented from flying up inside the room or even when it is released from the room to the outside.

In addition, the steam flows through the air inside the casing 12 and the casing 1.
Since it is lighter than the N2 gas that has flowed into the N2 gas, the first and second chambers are filled without remaining near the shipping port 14.
Therefore, even if a small amount of dust is generated in the room, the dust comes into contact with the steam, has no apparent weight, falls down and mixes with the sulfur powder, and does not remain suspended for a long time.

There is a concern that steam will escape from the upper fall port 21 and the lower outlet 14, but in reality, the sulfur M that moves continuously on both days substantially blocks the steam, and there is very little steam escaping.

Therefore, a large amount of steam escapes to the outside of the first and second rooms,
It will not come into contact with rotating parts or other parts and adversely affect these parts.

Furthermore, the amount of N2 gas that has flowed into the first and second chambers 40 and 42, where the generation of substantially the most dust is likely to occur within the casing 12, escapes to the outside is extremely reduced.
Therefore, the amount of N2 gas supplied can be significantly reduced.

The steam used in the present invention is preferably about 0.2k
g/cm□G in the range of about 3 kg/cm2G, more preferably about 0.3 kg/cm2G to about 1 kg/c
The pressure is in the range of m2G, and the temperature is approximately 30℃~
The temperature range is about 150°C.

Also, steam has a sulfur content of about 1 per 100 tons/hr.
It is preferred to inject at a rate of 00 kg/hr to about 150 kg/hr.

That is, about 0.2 kg/cm"G to about 3 kg/cm
Heated steam with a pressure of 2G and a temperature of about 30°C to about 150°C is used, and the heated steam is applied at a rate of about 100 kg/hr to 100 tons/hr of flaky sulfur.
By injecting at a rate of about 150 kg/hr, it was possible to effectively prevent the generation of dust without increasing the water content of the flaky sulfur.

On the other hand, when the heating steam temperature is about 130°C or lower, the moisture content of flake sulfur increases to 0.1 wt%,
Further, when heated steam at a temperature of about 150° C. or higher was used, the quality of the flaky sulfur product deteriorated and the effect of preventing dust generation was not sufficiently achieved.

In addition, when using heated steam at a pressure of 0.1 kg/cm2G and a temperature of 140°C, and injecting the heated steam at a rate of about 150 kg/hr or more to 100 tons/hr of flaky sulfur, the water content of sulfur is 0. .1 wt%, and no favorable results were obtained.

Furthermore, heating steam under the same conditions is applied at approximately 100 kg/hr.
When sprayed at the following ratios, the effect of preventing dust generation was not sufficient, and the generation of dust to the extent that it caused trouble during work was observed.

Referring to FIG. 4, another apparatus embodying the invention is shown.

The dust generation prevention device 10' has the same basic structure as the dust generation prevention device 10 shown in FIG. The only difference is that plates 60 and 62 are used.

The partition rubber plates 60 and 62 have mounting angles 64 and 66.
One end is attached to the casing 12 by the casing 12, and the other free ends are arranged to abut each other if the sulfur M is not transported 2 by the transport device 1.

When the sulfur M is conveyed, the tips of the partition rubber plates 60 and 62 are bent by the weight of the sulfur M, the tips of the drawing boards are separated, and the sulfur falls into the second baffle plate 30 through the gap.

The operation mode thereafter is the same as that of the second implementation device.

It will be understood that the second implementation device has two types of rubber partition plates at the inlet and outlet of the sulfur M, and therefore has an excellent effect of confining the steam inside the room.

The results of various tests conducted using each of the above-mentioned implementation apparatuses were as follows.

(1) Dust generation prevention effect Very good.

If you do not spray steam, it will be easier if you do not wear dustproof glasses.

Although it was impossible to get close to the steam, the generation of dust stopped within a few seconds after starting to spray steam.

(2) Moisture content of sulfur The moisture content of sulfur was 0.025 wt % regardless of whether steam was injected or not.

This value is acceptable for use as a product.

(3) Effect of static electricity caused by steam When measuring the static electricity of sulfur falling from the shipping port, it is over 60KV when no steam is injected.

When the value was shown and steam was injected, it became 40KV, indicating that the electrostatic potential of sulfur had decreased.

The method for preventing dust generation according to the present invention configured as described above completely prevents the generation of dust without substantially changing the moisture content of the material to be conveyed.

In addition, injecting heated steam tends to lower the 02% inside the casing, and the increase in relative humidity makes it easier for static electricity to leak, both of which work to prevent dust explosions. This has an extremely excellent effect.

Furthermore, the apparatus for carrying out the method according to the present invention has the advantage that it has a simple structure, low manufacturing costs, and low operating costs.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic front view of a first embodiment of a dust generation prevention device embodying the present invention. FIG. 2 is a longitudinal sectional view of the dust generation prevention device of FIG. 1. FIG. 3 is a schematic side view of the dust prevention device taken along line III--III in FIG. 1; FIG. 4 is a schematic vertical sectional view of a second embodiment of a dust generation prevention device embodying the present invention. 1: Conveyor device, 2: Conveyor belt, 3: Pulley, 10
: Dust generation prevention device, 12: Casing, 14: Shipping port, 16: First baffle plate, 18°20: Guide plate, 22,2
4: rubber plate, 30: second baffle plate, 32: third baffle plate, 34.36: exit plate, 38: partition plate, 40: first chamber,
42: Second chamber, 44, 46, 48, 50 varnish spray nozzle, 60. 62: Partition rubber plate.

Claims (1)

[Claims] 1. The pressure of the flaky sulfur being conveyed is approximately 0.2 kg.
/cm=G to about 3 kg/cm” About 100 kg of heated steam in the range of G and at a temperature of about 30°C to about 150°C is applied to 100 tons/hr of flaky sulfur.
A method for preventing the generation of flaky sulfur dust, characterized in that the generation of dust is prevented by injecting at a rate of 150 kg/hr to about 150 kg/hr. 2. The method of claim 1, wherein the pressure of the heated steam is in the range of about 0.3 kg/cm 2 G to about 1 kg/cm □ G.