JP2013079507A - Method for inhibiting scattering of demolition dust - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for inhibiting scattering of demolition dust, which can inhibit the scattering of the demolition dust without deteriorating demolition workability, and which enables the recovery of the dust wafting through the air without execution of a wash-out operation performed by adding a dust scattering inhibitor to sprinkled water and operations for the collection and suction of the dust.SOLUTION: The periphery of a demolition target building 6 is enclosed with a temporary enclosure 7 in such a manner that a void 8 exists; the height of the temporary enclosure 7 is set to exceed the height of the demolition target building 6 to some extent; an upper end is formed as an opening 9 for taking in a wind; an induced flow is drawn into the void from the opening 9; and dust produced due to the demolition of the building is retained in the void by the induced flow.

Description

  TECHNICAL FIELD The present invention relates to a method for suppressing dust scattering that occurs when a building is demolished in the construction field.

  When dismantling existing structures, the roof is usually dismantled, but dust is generated as shown in FIG.

Conventionally, the following techniques have been applied as means for suppressing dust generated during the dismantling of existing structures.
(1) Normal sprinkling with water spray guns A general dust generation suppression method suppresses dust scattering by moistening topsoil and dismantling members.
The following patent document is one of them, and as shown in FIG. 7, a water supply passage hole is formed in the swivel joint 2 disposed in the center of the slewing bearing of the crusher 1, and the water supply passage is made. A water spray nozzle 3 is arranged at the downstream end of the hole, and water from the water supply source is sprayed from the inside of the crusher 1 toward the periphery of the rocker beam for the crusher 1 through the water supply passage hole and the water spray nozzle 3. Moreover, the operation part of the stop valve 4 which operates the start and stop of watering was arrange | positioned inside the cab 5 of a construction machine.
Japanese Utility Model Publication No. 5-58758

  According to this patent document 1, the water discharged from the watering nozzle 3 can automatically follow the location where the crusher 1 performs crushing to perform reliable watering. Moreover, since the operation part of the stop valve 4 which operates the start and stop of watering is arrange | positioned in the driver's cab interior, it is very convenient because a driver | operator can be in the cab and can operate as needed. Therefore, it is possible to exert a sufficient effect for labor saving and dust generation prevention during crushing work.

(2) Mist watering By spraying water in a mist, the contact area with the dust is increased and the washing-off effect is improved.

(3) Dust-proof net The air speed by the net reduces the wind speed and reduces the amount of accumulated dust.
The following patent document discloses a plurality of nets that are supported by a structural part of a building and are arranged so as to protrude above the upper end of the building along the side of the building as a scattering prevention device using such a dustproof net. A holding part and a protective net that is held by the plurality of net holding parts at a position above the upper end of the building and covers the upper surface of the building, and the plurality of net holding parts are independent of each other. It is characterized by being vertically movable with respect to the building.
JP, 2011-17230, A According to this patent documents 2, during construction of a building, the scattered matter from the upper surface side can be prevented by a protection net, and the net holding part can move in the vertical direction. The height from the upper surface of the building to the upper protective net can be adjusted, and the height of the construction work space on the upper surface of the building can be adjusted appropriately. In addition, the height of the protective net in each area can be adjusted frequently according to the progress of construction in each area.

(4) Dispersion of dust coagulant Coagulates the surface of accumulated dust and earth and sand, and suppresses the rising of wind.
(5) Addition of dust scattering inhibitor to water spray By adding a surfactant or the like to the water spray, the compatibility between water and dust is improved and the washing-off performance is improved.
(6) Sealing of the dismantling work space Sealing the work space with temporary panels, etc. minimizes dust scattering outside the site.
(7) Dust collector By installing a dust collector or air intake duct near the dust generation point, collect the dust before it is scattered.

The conventional means (1) to (7) have the following problems.
(1) In normal sprinkling with water spray guns, it is possible to suppress the scattering of accumulated dust by moistening the topsoil and dismantling members, but when disassembling concrete and other members, the dust does not soak into the interior. Occurrence is inevitable, and there is a possibility that it will not reach the member during strong winds. The effect of washing off can hardly be expected because the contact surface with the dust is limited.
(2) Although mist-like water spray can improve the washing-off effect, it is more susceptible to wind than water spray guns, and the operator must always discharge water to the dismantling site like water spray guns.
(3) Dust-proof nets can reduce the amount of accumulated dust, but there is almost no effect of once generated dust staying on the premises. The effect is low.
(4) Although the dust coagulant spray prevents the dust from being scattered, it cannot suppress the generation of dust in the destruction work of concrete or the like.
(5) The addition of the dust scattering inhibitor to the water spray can improve the washing-off performance, but increases the cost of capital investment. Moreover, the effect becomes low at the time of a strong wind like other watering.
(6) Sealing of the dismantling work space can minimize dust scattering to the outside of the premises, but it increases the cost, restricts the size of heavy equipment to be used, and deteriorates the work environment due to sealing.
(7) In the case of dust collectors and intake ducts, unlike air supply, air is sucked from the entire intake surface, so there is no point in installing an intake port very close to the dust generation source, and there is a tendency for the equipment to become large. There are significant restrictions on the handling of equipment at the site of dismantling.

  The object of the present invention is to eliminate the inconveniences of the prior art, to prevent the dismantling dust from being scattered without impairing the dismantling workability, and to perform washing-off and dust collection suction by attaching a dust scattering inhibitor to the water spray. An object of the present invention is to provide a method for suppressing dismantling dust that can collect dust drifting in the air without damaging it.

  In order to achieve the above object, the present invention according to claim 1, the surroundings of the building to be demolished is surrounded by a temporary enclosure with a void, and the height of the temporary enclosure is set to a height that exceeds the building to be demolished to some extent. The gist is that the upper end is formed as a wind intake opening, the induced flow is drawn into the void from the opening, and the dust generated by the dismantling of the building is retained in the void by the induced flow.

  According to the first aspect of the present invention, the surroundings of the building are covered with a “void (gap)” provided between the building to be dismantled and the temporary enclosure, and the height of the temporary enclosure is set to exceed the building to some extent. Then, create a state where ventilation is possible in the void. At that time, the surrounding voids are connected through openings so that ventilation is possible.

  When the wind blows in the vicinity of the building height, there is a pressure difference that becomes positive pressure on the windward of the temporary enclosure pasted from the upper part of the building and negative pressure on the leeward side. As a result, there is an induced flow that draws the flow into the void on the leeward side of the building. Dust generated by the dismantling of the building is drawn into the void by the wake side attracted flow and stays on the site.

  When the wind blowing at the height of the building is strong, the induced flow into the void is strengthened, so that it resists scattering outside the site due to the turbulence of the wind, and is stable regardless of the wind speed. Can be expected.

  Basically, the shape of the conventional temporary enclosure may be devised, and this does not impair dismantling workability. In addition, dust floating in the air can be collected without washing off by attaching a dust scattering inhibitor to the water spray or collecting dust.

  The gist of the present invention described in claim 2 is that an overhanging portion is formed at the upper end of the temporary enclosure toward the inside of the opening.

  According to the present invention described in claim 2, it is possible to provide a “wind receiving” space of about 2 to 3 m between the overhanging portion and the roof height of the building to be demolished. An attraction can be triggered.

  As described above, the demolition dust scattering suppression method of the present invention can suppress the disassembly dust scattering without impairing the dismantling workability, and performs washing-off and dust collection suction by attaching the dust scattering inhibitor to the water spray. It is possible to collect dust floating in the air without doing anything.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal side view showing one embodiment of the demolition dust scattering suppression method of the present invention, FIG. 2 is a plan view of the same, FIG. 3 is a perspective view of the same, and 6 in FIG.

  The surroundings of the dismantling target building 6 are surrounded by a temporary enclosure 7. At that time, a void (gap) 8 of about 2 to 3 m is provided around the building between the temporary enclosure 7 and the dismantling target building 6. No special device is required for the member forming the temporary enclosure 7, and any panel or sheet can be used as long as the void 8 can be set.

  In addition, the upper end of the temporary enclosure 7 was formed as a wind intake opening 9 so that the height of the temporary enclosure 7 exceeded the dismantling target building 6 to some extent, for example, about 3 meters from the building height.

  At the upper end of the temporary enclosure 7, a laterally extending ridge-like protruding portion 10 of about 1 m is formed facing the inside of the opening 9, and about 2-3 m between the protruding portion 10 and the rooftop height of the building 6 to be demolished. A “wind” space will be provided.

  In addition, in order to ensure ventilation, the voids (gap) 8 on each side surface of the dismantling target building 6 are not divided.

  In this manner, the void (gap) 8 between the dismantling target building 6 and the temporary enclosure 7 is in a state in which ventilation is possible, and the wind blows near the building height, so that the temporary enclosure 7 pasted from the upper part of the building There is a pressure difference that is positive on the windward side and negative pressure on the leeward side. As a result, an induced flow that draws the flow into the void 8 on the leeward side of the building is generated.

  This induced flow descends as a circulating flow around the building 6 to be demolished by the void 8, but the dust generated by the demolition of the building is drawn into the void 8 by the attraction of the leeward side and stays in the site. .

  When the wind blows at the height of the building, the induced flow into the void 8 is strengthened, so that it resists scattering outside the site due to the turbulence of the wind and is stable regardless of the wind speed. "Effect" can be expected.

  The temporary enclosure 7 may be devised in the conventional shape, and disassembly workability is not impaired by providing the temporary enclosure 7.

  Basically, a strong circulation flow that causes dust to accumulate in the temporary enclosure 7 causes the dust to settle, so that air can be removed without washing off and dust collection suction by attaching a dust scattering inhibitor to the water spray. Dust floating inside can be collected.

  As another embodiment, as shown in FIG. 4, the water 11 may be sprayed in the middle or lower portion of the temporary enclosure 7, and can be effectively removed by spraying the water 11.

  This is because the dust circulation route is long in the void, so that the dust is well mixed, and the washing-off performance is higher than that of normal watering.

  In addition, as shown in FIG. 4, dust can be effectively recovered even if a dust collector 12 is placed under the temporary enclosure 7.

FIG. 5 shows the examination of the effect of dust scattering suppression voids by CFD (computational fluid dynamics) analysis. The results shown in Table 1 below were obtained.

  As can be seen from Table 1 above, the application of the dust scattering suppression voids resulted in 48 to 74% of dust accumulating in the premises under general wind speed conditions.

  In this way, the dust is carried by the wind to the downstream of the building along with the dismantling work, and is attracted into the “void”. As a result, the amount of scattering to the outside of the site is suppressed at a certain rate (in some cases 70% or more) compared to the normal temporary enclosure.

It is a vertical side view which shows one Embodiment of the dismantling dust scattering suppression method of this invention. It is a top view which shows one Embodiment of the dismantling dust scattering suppression method of this invention. It is a perspective view which shows one Embodiment of the dismantling dust scattering suppression method of this invention. It is a perspective view which shows other embodiment of the demolition dust scattering suppression method of this invention. It is explanatory drawing which shows the effect examination result of the dismantling dust scattering suppression method of this invention. It is explanatory drawing of demolition dust generation | occurrence | production. It is explanatory drawing which shows one of the prior art examples.

DESCRIPTION OF SYMBOLS 1 ... Crusher 2 ... Swivel joint 3 ... Sprinkling nozzle 4 ... Stop valve 5 ... Driver's cab 6 ... Demolition object building 7 ... Temporary enclosure 8 ... Void (gap)
9 ... Opening 10 ... Overhang 11 ... Water 12 ... Dust collector

Claims (2)

  Surround the building to be demolished with a temporary enclosure with a void, and set the height of the temporary enclosure to a height that exceeds the building to be demolished to a certain extent, and form the upper end as a wind intake opening, from the opening into the void A demolition dust scattering suppression method characterized in that wind is drawn as an induced flow, and dust generated by dismantling the building is retained in the void by the induced flow.   The dismantling dust scattering suppression method according to claim 1, wherein an overhanging portion is formed at the upper end of the temporary enclosure toward the inside of the opening.