JPH0263590A - Method and device for asbestos dust recovering and solidifying treatment - Google Patents

Abstract

PURPOSE:To prevent splashing and diffusing of asbestos dust by agitating the asbestos dust together with water under a negative pressure in a tank, further, adding cement thereto, and kneading the above-mentioned asbestos dust to a slurry under a negative pressure. CONSTITUTION:An agitating and kneading means 7 is provided to the tank 3 for recovering the asbestos dust. A discharge pipe 5 connected to a vacuum pump as well as an asbestos dust recovering pipe 2, a water feed pipe and a cement supplying pipe 6 are connected to the tank 3; further, an openable and closable discharge port 11 is provided thereto. The asbestos dust mixed with the water in the tank 3 is placed in the negative pressure state by the discharge air of the discharge pipe 5 opened in the tank 3 connected to the vacuum pump and the air and moisture remaining in the hollow part of asbestos fibers are expelled in the process in which the asbestos dust is agitated by the kneading means 7. After the cement is supplied, the valves of the water feed pipe and the cement supplying pipe are closed to knead the asbestos dust by the kneading means 7, by which the slurry thereof is formed. The air bubbles and moisture do not exist in the block of the solidified asbestos dust and, therefore, there is no possibility of splashing and diffusing of the asbestos dust.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method and an apparatus for collecting asbestos debris crushed and exfoliated from buildings, solidifying it with concrete, and disposing of it.

Conventional technology and its challenges Asbestos, which has traditionally been widely used as a building material, is being removed because it contains carcinogenic substances. It prevents asbestos from entering the body, and asbestos fibers float and pollute the atmosphere.
To prevent deterioration of the living environment, conventionally, when removing asbestos by crushing and peeling, the work site was surrounded with vinyl sheets to prevent asbestos dust from scattering, and workers were required to wear dust masks, work gloves, and Wear work clothes, etc.
After work, these items are disposed of to prevent asbestos dust from spreading.

In addition, as for the collection and processing of crushed and exfoliated asbestos waste, it is collected in a vacuum car or container car at the work site, transported to the solidification work site, mixed with cement and water, mixed to form a slurry, and then processed. The asbestos waste was discharged into a container and solidified, and the solidified asbestos waste was transported to a designated dumping site for disposal.

In the above-mentioned conventional technology, it is possible to solidify asbestos waste into lumps, but since asbestos fibers have a straw-like hollow shape, air and moisture are trapped in the hollow part and solidified. When the solidified asbestos waste blocks are left at the dumping site, the air bubbles sealed in the hollow parts of the asbestos fibers gradually seep out onto the block surface along with moisture, corroding the block surface and causing the asbestos fibers to erode. is exposed on the block surface and becomes a so-called "fluffy" state, which eventually scatters from the block surface and pollutes the atmosphere. Simply turning asbestos debris into concrete cannot completely prevent the scattering and dispersion of asbestos debris. It was difficult to do so.

Means and Effects for Solving the Problems The present invention has the configurations set forth in claims 1 and 2 as essential requirements, and the essential point is that asbestos debris is treated with water under negative pressure in a tank. Then, cement is added and the asbestos debris is kneaded and turned into slurry under negative pressure.

In this way, by stirring the asbestos waste together with water under negative pressure in the tank, the air and moisture contained in the hollow portions of the asbestos fibers are expelled and crushed.

Thereafter, cement is added and the crushed asbestos debris is kneaded under negative pressure to form a slurry, which is then discharged from the tank and solidified, so that the fluffing phenomenon that occurs in the past does not occur.

EXAMPLE FIG. 1 is a flowchart of the steps of the method of the present invention,
Asbestos waste from the work site, which is obtained by crushing and peeling off asbestos coatings sprayed on the ceilings and walls of buildings, or asbestos boards used as building materials, is first collected in a sealed tank.

The tank is then supplied with water.

In addition, if you supply water in advance into a sealed tank with a water supply pipe and asbestos waste is collected by suction into the sealed tank with an asbestos waste suction collection pipe that opens toward the water surface, the asbestos waste in the sealed tank will be can prevent scattering.

Next, the asbestos debris mixed with water in the sealed tank is stirred by the kneading means described later in the sealed tank, which is placed in a negative pressure state by the exhaust operation of an exhaust pipe connected to a vacuum pump and opened into the sealed tank. During this process, not only the air bubbles remaining in the asbestos waste but also the air and moisture remaining in the hollow parts of the asbestos fibers are expelled.

After the deaeration process is completed, water and cement (powder) are placed in the sealed tank.
After supplying cement to maintain a constant ratio of asbestos and water, the valves of the water supply pipe and cement supply pipe are closed, and the inside of the sealed tank is placed under negative pressure by the exhaust action of the exhaust pipe, and asbestos debris and water are mixed using a kneading means. Mix with cement to form a slurry.

The sludge-like asbestos debris is discharged into a predetermined processing container such as a plastic bag by closing the exhaust pipe and opening the discharge port provided in the sealed tank.

When all the muddy asbestos debris in the sealed tank has been discharged, the discharge ['' is blocked, the asbestos debris is collected again from the collection pipe, and the above-mentioned process is repeated. and discharge into a designated container.

The muddy asbestos waste discharged into a predetermined processing container is solidified within the processing container by the coagulation effect of cement, and is transported and dumped to a final processing site.

The sealed tank 3 can be a mobile tank mounted on a vehicle as shown in FIGS. 2 and 3, or a stationary tank (not shown), but there is no major difference in the structure of the sealed tank, so the mobile sealed tank 3 is used. FIG. 2 and FIG. 3 will be explained.

Inside the sealed tank 3 mounted on the moving vehicle V, there is a kneading drive li! which is horizontally suspended in the axial direction of the tank 3. l! There are ribbon screw-shaped kneading blades 8, 8' on +7 with a certain gap between them and the inner wall of the tank, and both shaft ends of the kneading drive shaft 7 pass through both end walls of the closed tank 3 in a sealed manner so that they can rotate freely. The kneading blades 8,8' are supported by the vehicle body via bearings, and the kneading blades 8,8' are provided symmetrically so that their twisting directions are opposite to each other. When the shaft 7 rotates in one direction, the objects to be treated are sent toward both ends, and when the shaft 7 rotates in the opposite direction, the objects to be processed are sent toward the center.

The asbestos waste collection pipe 2 opens at the upper part of the sealed tank 3, and as mentioned above, it not only collects asbestos waste into the sealed tank 3 by suction, but also performs a cement supply system that sucks out cement by operating a valve that is not cut properly. The pipe 6 is branched.

An exhaust pipe 5 connected to a vacuum pump (not shown) opens at the top of the closed tank 3 to create a negative pressure inside the closed tank 3.

Further, a discharge port 11 having a discharge chute and lid 10 that is opened and closed by operating a handle 9 is provided on the central side of the sealed tank 3, and the kneaded muddy asbestos debris is discharged into a processing container for solidification. Ru.

The crushed and exfoliated asbestos debris is collected into the sealed tank 3 through the asbestos collection pipe 2 when the inside of the sealed tank 3 is brought into a negative pressure state by the exhaust action of the exhaust pipe 5 connected to the vacuum pump.

At this time, a valve (not shown) of the cement supply pipe 6 is closed.

When a certain amount of asbestos waste is collected in the sealed tank 3, a certain amount of water is supplied into the tank 3 from a water supply pipe (the cement supply pipe 6 also serves as the cement supply pipe), and a valve (not shown) of the asbestos waste collection pipe 2 is closed. The kneading blades 8, 8' are driven to rotate, and asbestos debris is stirred in the closed tank 3 under negative pressure by continuing the exhaust action.

By this stirring action under negative pressure, not only air remaining between the collected asbestos debris but also air bubbles and moisture contained in the hollow portions of the asbestos fibers are removed.

Next, the valve of the cement supply pipe 6 is opened, and a predetermined amount of cement (powder) is sucked into the sealed tank 3 and added to the fluidized asbestos waste, and the valve is closed and the kneading blades ll1B, 8
' to knead. The weight ratio is 7 x 19 liters of asbestos waste and 0.7 liters of water.

Since the evacuation action in the closed tank 3 continues even during kneading, the inside of the closed tank 3 becomes a negative pressure state again, and the degassing action is continued.

As mentioned above, since air and water are not separated under negative pressure, asbestos debris that has been thoroughly mixed with cement and turned into mud,
By closing the valve of the exhaust pipe 5 and opening the discharge chute-cum-lid 10, the air is discharged to the outside of the sealed tank 3, and the kneading blades 8,
By the reverse rotation of 8', the muddy asbestos debris in the closed tank 3 is guided to the center as described above, and the entire amount of muddy asbestos debris is discharged from the discharge port II through the discharge shoe 10.

The discharged muddy asbestos debris is filled into a predetermined processing container (usually a plastic bag) and solidified by the coagulation action of cement.

After solidifying, remove the air from the container (bag) and seal it with a band to create a state similar to a vacuum pack. The asbestos waste packed in containers is then transported to a designated dumping site and reclaimed.

In addition, a water tank truck is moved to the work site, and a certain amount of water is poured into the sealed tank 2 from the water tank truck in advance.
Dry asbestos waste and cement are dropped by suction and fall perpendicularly to the water surface in the sealed tank 3 through the asbestos suction recovery pipe 2 and cement supply pipe 6, and the scattering of the asbestos waste and cement is suppressed and they are absorbed into the water storage. It is good to supply.

Hereinafter, stirring and kneading are carried out in a tank under negative pressure as described above.

Next, a second embodiment will be described based on FIGS. 4 to 6.

This asbestos waste collection and processing equipment 2 consists of a closed tank 23 equipped with stirring and kneading means similar to the one described above for mixing asbestos and cement into a slurry, and a closed tank 23 that is connected to this closed tank 23 to collect asbestos waste from the work site. Asbestos waste collection pipe 2 for collecting
2. A water (cement) supply pipe 26 for supplying water (and cement) to the sealed tank 23, a vacuum pump 24 for deaerating the inside of the sealed tank 23, and an exhaust line connecting the sealed tank 23 and the vacuum pump 24. 25, dust collection means 31, 32, 33 disposed in the exhaust line 25, a re-collection line 27 for returning asbestos debris collected by the dust collection means into the closed tank 23, a re-collection line 27, etc. It has a plurality of valves 35, 36.3738. A valve 39 is installed in the asbestos waste collection pipe 22 and the water (cement) supply pipe 26.
．． 40 are provided respectively. 41 is a discharge port.

Note that the power source is a vehicle engine, which drives a vacuum pump, a hydraulic pump, etc., which will be described later.

A means for deaerating the inside of the closed tank 23 is a vacuum pump 24. The vacuum pump 24 is a water ring type rotary pump,
Air from the exhaust line 25 and water from the circulating water tank 28 are simultaneously discharged to degas the tank 23. The supplied water flows back through the vacuum pump 24 and the circulating water tank 28, as indicated by arrow A. Further, a check valve 29 is provided immediately upstream of the vacuum pump 24 to prevent backflow of discharged air.

The safety standard at asbestos treatment sites is that there are no more than two asbestos fibers in 1 cc of air, and in order to achieve this standard, three dust collection means 3132.33 are installed in the exhaust line 25. The first dust collection means is a water-based dust collection device 31,
The second dust collector is a cyclone type dust collector 32, and the third dust collector is a filter dust collector 1F33. In this way, the means with a large particle size that can be collected is placed on the upstream side, that is, the means with a small separation limit particle size is placed on the downstream side, thereby achieving efficient collection. Larger asbestos debris naturally stays in the tank 23, but is sucked into the vacuum pump 24 and removed from the closed tank 23.
Asbestos debris having relatively small particles that has passed through is collected by these dust collection means 31, 32, and 33, and is prevented from dispersing into the atmosphere. The asbestos debris collected by the first dust collector 31 and the cyclone dust collector 32 is returned into the closed tank 23. A large number of valves are used to recover collected asbestos debris into the closed tank 23, and this operation will be described later.

Note that the re-collection line 27 may be directly connected to the sealed tank 23.

The first dust collector 31 has a curved flow path 31b formed by a plurality of partition plates 31a, and guides a mixture of air and asbestos debris to water 31d stored in the bottom 31c. Asbestos debris is collected in the stored water 31d when the air-fuel mixture turns in the bent flow path 31b by utilizing the difference in specific gravity.

The stored water side of this dust collector 31 is connected to the tank 23 via a switching valve 35.

The cyclone type dust collector 32 is a well-known device, and is a dust collecting means with a separation limit particle size of about 2 to 5 microns in -C classification. A collection tank 32a is provided downstream of the cyclone 32 via a switching valve 36, and the collection tank 32a is connected to the re-collection line 27.

Re-collection line 2 connected to asbestos waste collection pipe 22 at the most downstream side
7 has a suction valve 37 at the most upstream side and a re-collection line switching valve 38 at the midstream side. The collection tank 32a is connected between the suction valve 37 and the re-collection line switching valve 38.

Furthermore, a filter type dust collector 33 is located downstream of the cyclone 32. This filter type dust collector 33 is
It consists of a first filter 33a, a second filter 33b, and a third filter 33c, and the one with the smaller particle size that can be collected is provided downstream. Here, the third filter 33c is 0
．． Use one that can collect particles up to about 3μ.

The device in the figure includes an asbestos waste suction process, a water supply process,
The operations are performed in the following order: vacuum degassing process in a closed tank, cement supply process, stirring and kneading process, closed tank pressure increase process, kneaded material discharge process, closed tank pressure reduction process, and collected asbestos debris recovery process.

In the asbestos dust suction process, the vacuum pump 24 is operated with the valve 35 37.3840 closed (valve 36.39 open)
is activated, and the crushed and peeled asbestos debris from the work site is collected from the asbestos debris suction and recovery pipe 22 into the sealed tank 23.

Some of the asbestos debris that has been sucked in enters the exhaust line 25 from the sealed tank 23, but the dust collection means 31, 32, and 33 provided in the exhaust line collect these asbestos debris and release the asbestos debris into the atmosphere. prevent the emission of

Next, a certain amount of water is supplied to the tank 23 from the supply pipe 26.

The suction valve 39 is closed, and a degassing process is performed in which water and asbestos debris are stirred as described in the first embodiment, and then the vacuum pump 24 is operated to reduce the pressure inside the closed tank 23.

Next, a cement supply step is performed in which a certain amount of cement (powder) is suctioned into the closed tank 23 from the supply pipe 26 under reduced pressure.

Next, a kneading process is performed in which asbestos debris and cement are turned into slurry under negative pressure by a stirring and kneading means (not shown).

Next, a step is performed in which the suction valve 39 is opened and the pressure inside the sealed tank 23 is increased to atmospheric pressure. After the inside of the sealed tank 23 is brought to atmospheric pressure, the discharge port 41 is opened by operating the hydraulic cylinder 41', and the muddy asbestos debris is discharged into a predetermined processing container such as a plastic bag.

When all the muddy asbestos debris in the closed tank 23 is discharged, the discharge port 41 is closed, the valve 39 is closed, the vacuum pump 24 is activated, and the inside of the recovery processing device 21 is evacuated. At this time,
Only the switching valve 36 is open, and the other valves are closed.

Next, a process of collecting asbestos debris collected by the dust collecting means is performed, after opening the switching valve 35 and letting the water 31d stored in the first dust collecting device 31 flow out into the re-collection line 27.
After closing the valve 35 and then closing the switching valve 36, the suction valve 37 and the re-collection line switching valve 38 are opened to collect asbestos debris in the collection tank 32a into the closed tank 23.

After completing the above step, the inside of the first dust collector 31
The asbestos waste collection process is repeated with the valves 35, 37, and 38 closed and the valves 36, 39 open.

The muddy asbestos waste discharged into a predetermined container is solidified within the processing container by the coagulation effect of cement, and is transported to a final processing site and disposed of.

Note that the re-collection step may be performed between the asbestos waste suction step and the cement supply step.

Effects of the Invention Unlike the conventional method in which asbestos waste is kneaded with cement and water under normal pressure to solidify it, the present invention expels the air and moisture contained in the hollow parts of asbestos fibers and adds cement and water. Since it solidifies, there are no air bubbles or moisture in the solidified asbestos waste block, and therefore, even if the block is left alone, the fluff of asbestos waste will not be formed on the block surface, and the asbestos waste will not scatter. There is no risk of spread.

Incidentally, all of the asbestos debris that has been sucked out is recovered and processed within the device by performing the re-collection operation, which is highly effective in preventing air pollution.

[Brief explanation of the drawing]

FIG. 1 is a flowchart of the present invention, FIG. 2 is a side view of an asbestos waste collection and processing device mounted on a moving vehicle according to the first embodiment,
3 is a plan view of FIG. 2, FIG. 4 is a schematic diagram of the second embodiment, FIG. 5 is a side view of a vehicle implementing the second embodiment, and FIG. 6 is a plan view thereof. 7...Kneading drive shaft (stirring and kneading means) 8.8'...Kneading blades (stirring and kneading means) 11, 41.
...Discharge port 2I...Asbestos waste collection and processing device 25...Exhaust line 27...Re-collection line 31...First dust collector 32...Cyclone type dust collector 32a...Capture Collection tank 33... Filter 2 a dust device 2.22... Asbestos waste collection pipe 323... Tank 24... Vacuum pump 5... Exhaust pipe 6.26... Cement supply pipe Figure 5 Figure 6

Claims (3)

[Claims] (1) Collect asbestos waste in a tank, stir the asbestos waste with water in the tank under negative pressure, further add cement and knead the asbestos waste under negative pressure to form a slurry, and process the slurry asbestos. A method for collecting and solidifying asbestos debris, characterized in that the debris is discharged from the tank into a container and solidified in the container. (2) A tank for collecting asbestos waste is provided with stirring and kneading means for the asbestos waste, and an exhaust pipe connected to a vacuum pump, an asbestos waste collection pipe, a water supply pipe, and a cement supply pipe are connected to the tank, and the tank can be further opened and closed. An asbestos waste collection and processing device characterized by having a discharge port. (3) The asbestos waste recovery and processing device according to claim 2, further comprising means for collecting asbestos waste flowing into the exhaust pipe from the tank and returning it to the tank.