JP2008012471A - Prevention of scattering of scatterable dust of asbestos, or fixing liquid thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely and economically suppress or prevent scattering of dust (asbestos dust) caused by weathering of sprayed material of asbestos or demolition. <P>SOLUTION: An appropriate amount of fixing liquid formed by homogeneously blending a surfactant and a thickener to a solution of polysaccharide like gum arabic, is sprayed to the sprayed material of asbestos to moisturize/fix dust of weathered sprayed material, to suppress or prevent scattering of dust caused by demolition. Even if the fixing liquid is dried, scattering of dust caused by demolition of the treating object can be suppressed or prevented, by re-moisturizing with water and recovering viscosity of the fixing liquid. Inclusion of water into the thickener swells the volume thereof to facilitate exfoliation of the treating object. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention includes insulation, fire resistance or anti-condensation including asbestos, etc., weathering of spraying materials for heat insulation and sound absorption, etc., construction materials including asbestos, etc., and dismantling of incinerators, replacement / removal of microbial filtration filters (HEPA filters), etc. The present invention relates to a dust scattering preventive or fixing (fixing) liquid for the purpose of fixing or preventing dust and dust (asbestos powder, ash containing dioxin, dust containing microorganisms such as viruses) and the like, and sterilization.

Dust (asbestos powder) generated during the weathering or demolition work of spray materials containing asbestos, etc., has been seen as a problem in the near future, as it spreads in the wind and spreads widely into the space, adversely affecting the health of a wide range of nearby residents. ing.
Therefore, there is an urgent need for the removal of existing weathered spray materials such as asbestos or the dismantling / removal of building materials containing weathered asbestos. In order to prevent dust from being scattered, the construction object should be covered with a curtain in advance to shut it off from the outside, or the existing spraying material may be sprayed with water containing a surfactant and thoroughly wetted. In general, after the removal of the spraying material and the like is suppressed, the liquid containing the organic polymer resin agent is applied to the surface to fix the remaining dust.

However, it is difficult to sufficiently achieve the purpose of preventing dust scattering simply by using a curtain to block the construction object from the outside world, and this is only an auxiliary means.
The method of suppressing the generation of dust by spraying water is simply an operation that suppresses the generation of dust by infiltrating water into the material to be treated to prevent the generation of dust during construction. Need water. Therefore, it is necessary to prepare wastewater treatment facilities before construction, and the resulting sludge will be regenerated after drying. There are problems such as becoming.

In addition, when a liquid containing an organic polymer resin agent or the like is applied, the concentration of the volatile solvent in the closed space at the time of construction and treatment of the toxic gas is required due to evaporation of the volatile solvent contained in the resin. What will come. Furthermore, since the adhesion between the material to be treated and a member such as a concrete surface or the surface of a steel frame improves when dried, there is a problem that it becomes difficult to dispose of the material during disassembly.
That is, when time passes, dust tends to be generated during peeling and dismantling.

“Exposure Prevention Manual for Asbestos Dust” in the Demolition of Buildings Construction and Industrial Accident Prevention Association Planning and Development Division August 9, 2005 First edition issued

  The problem to be solved is that the defects inherent in the above-mentioned conventional method are removed, and dust (asbestos powder) generated from the spraying material etc. is widely scattered in the space with weathering or dismantling by simple and economical means. The purpose of the present invention is to provide a moistening / fixing solution that effectively fixes or suppresses the above, thereby sanitizing the treatment / disassembly environment of the spray material containing asbestos and promoting the treatment work.

  The present invention provides a wet / fixing solution for scattering dust such as asbestos, in which a surfactant and a thickener are uniformly mixed in an aqueous polysaccharide solution such as gum arabic and gum, and this is treated with a spraying material or the like. It is characterized by fixing the dust by spraying and spontaneously penetrating objects.

(A) By mixing an appropriate amount of a surfactant, the present liquid can easily permeate into an object to be treated, thereby exerting a wetting effect and producing a bactericidal effect.
(B) After wetting the object, dust (asbestos powder) is fixed by viscosity such as gum arabic and rubber to suppress scattering, and fixed after drying.
(C) Although the thickener synergizes with the fixation by improving the viscosity in a wet state, it is poor in adhesiveness, so that it is easily peeled off by re-wetting after drying.

(D) Even after the liquid has dried, the viscosity of the liquid can be restored and the generation of dust can be suppressed by replenishing the water again. In other words, dust is fixed to the object to which the fixing liquid has been applied at one end, thereby suppressing (preventing) dust scattering. Moreover, even after drying, by replenishing the water, the liquid (solidified part) can easily recover its viscosity and suppress dust scattering. And it becomes easy to peel by the effect of a thickener or the like.
(E) By using this liquid, it is possible to wet and fix the object with a single spray.
(F) Furthermore, since this liquid is simply a solution, there is no risk of generation of harmful gases during construction.

(G) That is, a fixative solution in which a surfactant and a thickener are homogeneously blended in an aqueous solution of polysaccharides such as gum arabic and rubber is sprayed onto a spraying material such as weathered asbestos to allow natural penetration. A substance that can become dust existing in the spraying material is fixed due to adhesiveness, and the effect of preventing dust from scattering to the outside during weathering or dismantling treatment is obtained.

  Even if the spraying material is dried after spraying this liquid, the viscosity of the fixative is easily restored by replenishing the water. Generation can be suppressed. Further, since the thickener contains moisture, the volume expands and the adhesiveness is inferior, so that the treated spraying material is easily peeled off from the substrate. Since the treated spraying material has lubricity in the fixing solution, it is easy to peel off cleanly and does not generate dust after peeling.

  Dismantling of incinerators with ash containing dioxins, and replacement of high-accuracy sanitizing filters (HEPA filters) to prevent microbial contamination in biohazard facilities, etc. Filters for microorganisms such as viruses and bacteria scattered by dismantling work It is possible to carry out the fixation and the sterilization treatment at the same time, and by adding an appropriate amount of a surfactant, it is possible to fix even dust that repels water, such as oil dust.

  The cost spent for fixing or dismantling and removing weathered asbestos is, according to experience, a large percentage of the dust-spreading prevention work in the preparation process. Ease is greatly influenced by whether the work can be proceeded economically and accurately. It is believed that the above characteristics of this liquid are suitable for carrying out the work of fixing or dismantling weathered asbestos in a healthy and economical manner.

  Each component composing the present liquid is not necessarily limited to the names (trade names) exemplified in the examples as long as it is an agent distributed in the industry as an adhesive, a surfactant and a thickener. In addition, the composition ratio shall be a range in which the performance of the properties expected for each agent is not impaired.

Formulation (weight ratio)
Arabic rubber powder 5% (adhesive)
Polyethylene glycol (PG4000) 1% (surfactant)
Carboxymethylcellulose (CMC) 1% (Thickener)
93% water
Fixing solution adjustment

Dissolve homogeneously in hot water at 60-80 ° C.
Spraying method

Spray low pressure mist with plunger pump. The spray nozzle of the sprayer is separated from the surface to be processed by about 30 cm, and the spraying area is adjusted so as to have a diameter of about 30 cm to 50 cm, and sprayed uniformly and uniformly on the processing target surface at an angle of 45 ° to 90 °. At this time, the spray pressure is adjusted so that the spray material does not scatter. Make sure that there is no surface tension of the fixative on the spray surface.
Application amount: 20% to 30% of the thickness / volume of the non-treated material.
(In the case of a thickness of 1 to 3 cm) An amount sufficient for sufficient wetting at 5 times or less of the actual volume Example: 1 liter / m ²
However, the spraying material does not peel or collapse due to the weight of moisture.
Confirmation of effect

During the work, dust was measured and the following results were obtained.
(1) Dust concentration measurement value Dust concentration before work 0.03 mg / m ³
Dust concentration during work 0.016mg / m ³
Dust concentration after work 0.018mg / m ³
(2) Asbestos analysis

Before work Yes (50% contained)
Air concentration during work 0.06f / m ³
No air concentration after operation No change in fire resistance after treatment

Construction sites for fire and heat resistant spray materials including asbestos, etc. have no spare time for public buildings, factories and other private houses located in or around the city. Many of these building materials have undergone a period of weathering of asbestos after aging, and after the health damage to asbestos, etc. has been found, they should be removed or disassembled as soon as possible. Is often desirable.
However, most of them are located in the city, and during construction, asbestos dust may be scattered on the adjacent surrounding area and affect the health of nearby residents. It is believed that the characteristics of this liquid are widely exhibited during the fixing or dismantling of building materials including weathered asbestos.

Claims (1)

An anti-scattering or fixing solution for asbestos and other dusts, which is a mixture of a surfactant and a thickener in an aqueous solution of polysaccharides such as gum arabic and gum.