WO1991004805A1

WO1991004805A1 - An asbestos-containing materials removal assembly and method

Info

Publication number: WO1991004805A1
Application number: PCT/US1990/005515
Authority: WO
Inventors: Dennis H. Green; Stephen C. Johnson
Original assignee: Envirestore Technologies, Inc.
Priority date: 1989-09-28
Filing date: 1990-09-27
Publication date: 1991-04-18
Also published as: AU6514590A

Abstract

An ACM removal assembly (10) is disclosed, including: a nozzle (16, 18, 20) for directing a pressurized fluid (15) against ACM (12) for dislodging the ACM (12); a fluid supply reservoir (25) connected to the nozzle (16, 18, 20); a housing (30) which supports the nozzle (16, 18, 20) and capturingly receives spent fluid (21) and dislodged ACM (13); and a material handling and separating system (170) which includes coarse separating apparatus (130, 146) for coarsely separating the spent fluid (21) from the dislodged ACM (13) and fluid return conduit (150, 152) for returning coarsely separated fluid to the fluid supply reservoir (25). Also disclosed is a method for removing ACM (12) from a building structure (14), including: sealingly circumscribing a small-area building region (180) having exposed ACM (12) with an ACM containment apparatus (30); removing ACM (12) from the circumscribed building region (180) with a fluid spray blast (15); combiningly capturing dislodged ACM (13) and spent fluid (21) from the spray blast (15) in the containment apparatus (30); coarsely separating a portion of the ACM (13) from the combined ACM (13) and spent fluid (21); and reusing the coarsely separated fluid to remove ACM (12) from the building.

Description

AN ASBESTOS-CONTAINING MATERIALS REMOVAL ASSEMBLY AND METHOD

Background of the Invention The present invention relates to a system for removing asbestos-containing materials (ACM) from buildings.

Since before the second World War through the early 1970*5, as much as 300 million tons of asbestos mineral had been used in building construction in the United States. By the early 1970's, medical evidence began to establish that asbestos exposure can cause severe and irreversible lung damage and various forms of cancer. By the early 1980's, public concern over the hazards associated with asbestos became manifest in legislation which (1) limited the use of asbestos in new construction; (2) specified procedures for asbestos removal in buildings; (3) required removal of asbestos- containing materials prior to building remodeling or demolition; (4) required management of asbestos in schools.

The U.S. Environmental Protection Agency has estimated that about 45,000 schools and 73,000 public and commercial buildings contain some form of asbestos- containing materials (ACM) . These ACMs are typically (1) surfacing materials sprayed or troweled onto ceilings and walls; (2) thermal insulation on pipes, ducts, boilers and tanks; (3) miscellaneous materials such as ceiling and floor tile and wallboards.

ACM removal is currently a heavily labor-intensive industry. Typically, surface ACM is removed by laborers using paint scrapers. The ACM is initially hand-wetted using sponges, low pressure water spray or the like, in order to reduce the amount of asbestos dust created during scraping. Thereafter, the ACM is scraped from its location in the building and allowed to fall to the building floor. Next, the dislodged ACM is shoveled up manually and placed in plastic bags. After the initial scraping of building surfaces with paint scrapers and the like, a final cleanup process is initiated to remove ACM from joints, crevices, beams, and other hard-to-reach areas in which large paint scrapers and the like are unsuitable. This cleanup process sometimes includes using pressurized water to blast the remaining ACM from its location on the building structure. Thereafter, all ACM, water, and other debris on the floor of the building is removed, typically by wet/dry vacuum units such as the type used in most shop and maintenance areas. As a final step, all surfaces of the building and enclosure are wiped down to remove any remaining ACM dust, etc.

Although regulations for asbestos removal vary from state to state, typically the area from which ACM is to be abated is required to be sealed off from the surrounding environment to prevent discharge of airborne asbestos fibers into the surrounding environment. During any period in which ACM removal is taking place, the sealed-off area within the building enclosure is required to remain at a negative air pressure with respect to the surrounding environment. The negative air pressure is typically provided by a "hepafiltered" vacuum source. "Hepafilter" refers to a filter which removes substantially all airborne particles having a particle diameter of greater than 0.3 microns. During asbestos removal, the air within the sealed enclosure is sampled on a regular basis to determine the density of airborne particles within predetermined ranges. Workers within the enclosure are required to wear approved protection gear having a hierarchy based upon the airborne particles within the building enclosure. In order to reduce costs associated with the more expensive protection gear, most contractors attempt to reduce airborne particle concentrations within the enclosed ACM removal area to a minimum, typically by providing a replenishing air flow which replaces the air within the enclosure on the order of four times per hour.

In order to prevent asbestos particles contained on the workers clothing and body from entering the atmosphere outside of the enclosed area, a triple air lock is typically provided at the entrance to the enclosed area. In the first area of the triple air lock positioned adjacent to the enclosed area, workers remove their protective gear and clothing, generally depositing it in sealed receptacles which are later removed from the area and cleaned or destroyed. After disrobing, a worker enters an intermediate area of the triple air lock which contains a shower. Each worker showers in this area and then progresses to the third area of the triple air lock in which clean clothes, etc. , are provided. The water from the intermediate air lock shower is filtered to a particle size permissible for discharge into the surrounding sewer system, or ground water environment, typically 5 microns. In some cases, water which has been vacuumed from the floor of the enclosed ACM removal area by wet-vacuum in the final stages of cleanup is dumped into the worker's shower for filtering by the shower filter system. However, in most cases, the wet-vacuum container contains enough large ACM particles to prevent use of the shower as .a filtering system, in which case all of the water and particles contained in the wet- vacuum are transferred to a barrel or other sealed receptacle for removal to an approved disposal site or for subsequent filtering. Due to the labor, dump fees, and inconvenience associated with removing large quantities of contaminated water to an asbestos disposal site, the use of water in ACM removal is minimized. Generally, blast spray water, when used at all, is applied at relatively high pressures, e.g. 5,000 psig or more, to decrease the total volume of water needed in any blast spray removal operations. The use of large amounts of water also damages underlying building structure such as floors and ceilings and has thus also been minimized to prevent unnecessary damage to the building.

Objects of the Invention

It is an object of the present invention to provide an ACM removal system which eliminates much of the hand labor associated with ACM removal.

It is another object of the present invention to provide an ACM removal system which is more cost- efficient than current ACM removal methods.

It is another object of the present invention to provide an ACM removal system which is relatively faster than current ACM removal methods.

It is another object of the present invention to provide an ACM removal system which enables the use of relatively lower blast water pressure than that currently used in the industry.

It is another object of the present invention to provide an ACM removal system which utilizes a relatively large volume of water flow for the removal and handling of ACM.

It is another object of the present invention to provide an ACM removal system which reduces the density of airborne particles created during ACM removal as compared to current methods.

It is another object of the present invention to provide an ACM removal system which eliminates the need- for a negative pressure environment in the building enclosure in which ACM removal is taking place.

It is another object of the present invention to provide an ACM removal system which provides a continuous process in which ACM is removed from a building in slurry form and in which blast water is coarsely removed from the ACM slurry and reused for further ACM removal and in which the blast water is more finely removed from the ACM slurry and discharged into the local municipal sewer at the completion of ACM removal whereby the necessity of disposing of large quantities of waste water at an approved ACM dump site is eliminated.

It is another object of the present invention to provide an ACM removal system which utilizes a mobile housing unit which encloses a blast spray and which serves as an initial collection area for ACM and waste blast spray.

It is another object of the present invention to provide an ACM removal system which utilizes a mobile housing unit which provides a localized enclosure in an specific region of a building in which ACM removal is taking place to prevent propagation of water overspray and ACM particles into the surrounding environment.

Summary of the Invention The present invention may include an ACM removal assembly comprising: nozzle means for directing a pressurized fluid against ACM which is supported on a building structure for dislodging the ACM; pressurized fluid supply means operably connected to said nozzle means for supplying fluid under pressure thereto; and housing means for supporting said nozzle means therein and for capturingly receiving spent fluid and dislodged ACM.

The present invention may also include a method for removing ACM from a building structure comprising: sealingly circumscribing a first building region having exposed ACM with an ACM containment apparatus; removing ACM from the circumscribed building region with a fluid spray blast; combiningly capturing dislodged ACM and spent fluid from the spray blast in the containment apparatus; separating a portion of the ACM from the combined ACM and spent fluid; and reusing the coarsely separated fluid to remove ACM from a second building region.

The present invention may also include an ACM removal assembly comprising: nozzle means for directing a pressurized fluid against ACM which is supported on a building structure for dislodging the ACM; pressurized fluid supply means operably connected to said nozzle means for supplying fluid under pressure thereto; housing means for supporting said nozzle means therein and for capturingly receiving spent fluid and dislodged ACM; and material handing and separating means operably connected to said housing means for receiving combined spent fluid and dislodged ACM from said housing means for separating said spent fluid from said dislodged ACM; said material handling and separating means comprising coarse separating means for coarsely separating said spent fluid from said dislodged ACM and fluid return means for returning coarsely separated fluid to said pressurized fluid supply means; said material handling and separating means comprising fine separating means for receiving coarsely separated fluid from said coarse separating means and for finely separating ACM therefrom.

Brief Description of the Drawings Illustrative and presently preferred embodiments of the invention are shown in the accompanying drawings in which:

Fig. 1 is a schematic illustration of an ACM removal system. Fig. 2 is an elevation view of a portion of an ACM removal system engaged with a building structure ceiling area from which ACM is to be removed.

Fig. 3 is a top plan view of a nozzle assembly and housing unit.

Fig. 4 is a cross sectional elevation view of a nozzle assembly and housing unit.

Fig. 5 is a perspective view of an alternative embodiment of a portion of an ACM removal system.

Fig. 6 is another embodiment of an ACM removal system.

Fig. 7 is a perspective view of a sump assembly.

Detailed Description of the Invention Fig. 1 schematically illustrates an ACM (asbestos- containing material) removal assembly 10 which is adapted to remove ACM 12 from supporting building structure 14. The ACM removal assembly in general comprises nozzle means 16, 18, 20, Figs. 3 and 4, for directing a spray of pressurized fluid 15 such as water against ACM 12 for dislodging it. The nozzle means 16, 18, 20 are operably connected to pressurized fluid supply means 25, Fig. 1, which supplies fluid under pressure thereto. The nozzle means 16, 18, 20 are supported within housing means 30 which is adapted for capturingly receiving spent fluid 21 and dislodged ACM 13, Fig. 4. Material handling and separating means 84, 124, 130, 146, 158, 162, etc., are operably connected to the housing means 30 for receiving combined spent fluid and dislodged ACM from the housing means 30 for separating the spent fluid 21 from the dislodged ACM 13. The material handling and separating means includes coarse separating means 130, 146, etc., for coarsely separating the spent fluid from the dislodged ACM, and fluid return means 150, 152, etc., for returning coarsely separated fluid to the pressurized fluid supply means 25. The material handling and separating means also comprises fine separating means 158, 162, etc., which is typically used only at the end of an ACM removal job. The fine separating means is adapted for receiving coarsely separated fluid from the coarse separating means 130, 146, etc., for finely separating ACM from the coarsely separated fluid to provide a finely filtered fluid which is sufficiently filtered to be discharged into the local sewage system or local earth/water environment. A negative air pressure may be provided within the housing means 30 and sealing devices, e.g. 46, 52, 62, may be provided in associated with the housing to prevent fluid overspray and contamination of the air within the building enclosure with ACM airborne particles. The housing assembly 30 may be mounted on a wheeled carriage 94 or the like to facilitate movement of the housing assembly 30 and associated spray nozzle 16, 18, 20 to selected areas within the building from which ACM is to be removed. Having thus described the ACM removal assembly 10 in general, various specific features of the assembly will now be described in further detail.

As illustrated in Figs. 3 and 4, a plurality of spray nozzles (e.g. three spray nozzles, 16, 18, 20, which may be conventional washjet cleaning nozzles such as that sold under model designation 6504-1/4 MEG by Spraying Systems Company of North Avenue, Wheaton, Illinois, 60188) are mounted on a spray nozzle conduit 22 which may be, e.g., a 3/4-inch circular pipe. Spray nozzle conduit 22 is capped at one end thereof and is connected at the other end thereof to a water line 24 which is connected to a water supply reservoir 25. Reservoir 25 may be, e.g., a 50-gallon supply reservoir. A water pump 26 is operably mounted in water line 24. The pump power rating, e.g. 15 h.p. , is matched to the water requirements of the spray nozzle. In a preferred embodiment, the nozzles are adapted to apply water at a pressure up to 5000 psi and preferably are operated in a range from 1000-2000 psi. The flow rate requirements of the nozzles are typically up to 10 gallons per minute each and are preferably operated in a range of 2-5 gallons per minute each. As illustrated in Fig. 1, a signal-actuated control valve 28 may be provided in the water line 24 for shutting off the supply of water from the water supply reservoir 25 in response to a control signal, as further described below. A branch line 29 connected to line 24 is adapted for use in removing water from reservoir 25 at the completion of an ACM removal job is also described below. Flow of water into line 29 may be controlled by operation of conventional control values 31 and 33 located in lines 29 and 24, respectively.

Housing 30, as best illustrated by Figs. 2-4, comprises an enlarged upper end portion 32 terminating in a square, upper opening 34, which may have an open area of, e.g., 1 square foot. The enlarged upper end portion may have an inverted, irregular pyramid-type shape. The spray nozzle conduit 22 is supported on two sidewalls of the enlarged upper end portion 32 through appropriately- sized bores therein. The spray nozzle conduit 22 may be positioned, e.g., 2-4 inches below the upper edge of opening 34. The centerline of each spray blast from nozzle 16, 18, 20 may be adjustable and may be inclined, e.g., 45° with respect to the upper periphery of opening 34. The housing 30 also comprises a restricted lower end portion 36 which is integrally formed with the upper end portion 32 and which terminates in a lower opening 38 which may be circular in shape and which may have an opening area of, e.g., 0.02 square feet. In one embodiment of the invention, dislodged ACM and spent fluid 13 is capturingly received in the housing upper end portion 32 and is discharged by gravity through the restricted lower end portion 36. In another embodiment of the invention, as illustrated in Fig. 4, conveying means such as an auger 40 are provided in the lower end portion 36 to facilitate removal of ACM and spent fluid from the housing 30. The auger 40 may be conventionally mounted within the housing and may be powered by a conventional auger motor 41, Fig. 2.

As illustrated in Figs. 3 and 4, a vacuum monitoring gauge 42 is provided in the housing for monitoring the pressure therein. The vacuum monitoring gauge 42 may be operably connected with water line shutoff valve 28 for terminating the supply of water to spray nozzle 22 in the event that the pressure within the housing 30 rises above a predetermined negative air pressure value, e.g. above - 0.5 psig.

A conventional blowoff valve 44 provided with a hepafilter, which may be set at, e.g., 1.0 psig, is provided as a safety device for relieving positive pressure within housing 30 in the event of system malfunction.

A bristle brush-type seal 46 is provided about the periphery of opening 34 by a plurality of closely-spaced brush bristles which may each have a length of, e.g., 1.0 inches. The bristle seal is adapted to allow inflow of air therethrough while restricting nozzle overspray and restricting discharge of ACM particles into the surrounding atmosphere.

A pressure ring 52 which circumscribes the upper housing opening 34 may be fixedly mounted on the housing 30, as illustrated in Figs. 3 and 4. Pressure ring 52 may have an annular opening 54 at an upper end. Pressurized air is sent to pressure ring 52 through at least one inlet opening 55 which may be provided in a lower portion thereof. The inlet opening is placed in fluid communication with a pressurized air source such as air compressor 58 through a pressure hose 56. Compressor 58 may be located inside or outside of the building enclosure 11. A conventional shutoff valve 60 may be provided in the pressure hose 56 for terminating air flow from the air source 58. The pressurized air source may provided air at a pressure of, e.g., 2.0 psig to pressure ring 52 at a flow rate of, e.g., 50 cfm. As best illustrated by Figs. 2-4, a vacuum ring 62 may be mounted on the pressure ring 52 in circumscribing relationship therewith. The vacuum ring 62 comprises an annular opening 64 in an upper end portion thereof. Vacuum ring 62 is placed under negative pressure, e.g. - 0.9 psig, by a vacuum source 68 which communicates with the vacuum ring 62 through vacuum hose 66 and vacuum ring inlet opening 65. A vacuum shutoff valve 72 may be provided in association with the vacuum source 68 to terminate air flow thereto. The vacuum source 68 may be a conventional vacuum pump provided with hepafilters for filtering the air discharged therefrom down to a particle size of less than 0.3 microns in diameter. The airflow rate through vacuum ring 62 may be, e.g., 50 cfm. Alternatively, vacuum ring 62 may be placed under vacuum by the vacuum pump associated with the wet/dry vacuum assembly 84 described below.

Second end third annular bristle seals 53, 63 similar in construction and use to annular bristle seal 46 may be provided in association with annular pressure ring 52 and annular vacuum ring 62, respectively, as shown partially in Fig. 3. As best illustrated by Fig. 2, the lower opening 38 of housing 30 communicates with a wet/dry hepavacuum assembly 84 through a flexible conduit 82 which is connected to housing 30 and to the vacuum pump 86 by appropriate adapters. In one embodiment of the invention, the flexible conduit comprises a diameter of approximately 2.0 inches and the wet/dry vacuum assembly comprises a tank 88 having a capacity of 30 gallons. The wet/dry vacuum assembly may have a vacuum pump 86 capable of providing a negative pressure of approximately -3.6 psig within housing 30. The wet/dry vacuum assembly 84 may be a conventional wet/dry vacuum assembly such as are used at most construction sites and maintenance shops, e.g. that manufactured under the product designation 2HP Wet/Dry Hepavac by Control Resource Systems, Inc., 670 Mariner Drive, Michigan City, Indiana, 46360. The wet/dry vacuum assembly is adapted to collect an unprocessed slurry of water and ACM in tank 88 thereof. A second flexible conduit 92 is connected to tank 88 at an opening in the bottom thereof and is connected at an opposite end to material handling and separating means as described in further detail below.

In one preferred embodiment of the invention, the wet/dry vacuum assembly 84 is mounted on a wheeled carriage assembly 94 and the housing 30 is mounted on a pivot assembly 96 which is, in turn, supported on the wet/dry vacuum assembly and wheeled carriage assembly. The pivot assembly 96 may comprise a first pivot arm 98 mounted on top of tank 88 and having a counterweight 102 supported at one end thereof and a second pivot assembly 104 mounted at the other end thereof. A second pivot arm 106 is mounted on the second pivot assembly at one end thereof and a third pivot arm assembly 108 is mounted at the other end of the second pivot arm 106. A biasing spring 110 is mounted in circumscribing relationship about the third pivot arm assembly 108 between the second pivot arm 106 and a collar assembly 112. The collar assembly 112, in turn, supports the housing 30 thereon. Biasing spring 110 is adapted to urge the collar assembly 112 and housing 30 upwardly so as to urge bristle seal 46 against a building region from which ACM is to be removed.

As illustrated by Fig. 1, flexible conduit 92 places wet/dry vacuum tank 88 in fluid communication with a slurry holding tank 124. A pump 122, which may be located inside or outside of enclosure 11, having a capacity at least as great, and preferably about twice as great, as the capacity of blast water supply pump 26 is adapted to pump slurry from tank 88 to slurry holding tank 124. Slurry holding tank 124 may have a capacity of 200 gallons.

A pump 126 operably mounted in a slurry line 128 is adapted to pump slurry from slurry holding tank 124 to a first separator device 130 such as a conventional dewatering separator, which may be a Lakos AXL series AXL-0100-B dewatering separator manufactured by Lakos Separators USA (a division of Claude Laval Corp.), 1911 North Helm Avenue, P.O. Box 6119, Fresno, California, 93703-0119. Such a separator device 130 typically removes ACM particles having a diameter of greater than 74 microns. The separator device 130 discharges separated ACM particles 134 to an ACM collection tank 136 and discharges initially separated slurry through slurry line 144. The discharged ACM particles 134 may be further dewatered to remove fluid bulk therefrom as by a dewatering screen 132 which may be a conventional dewatering screen such as that sold under model designation Hydroscreen model HS-18 by Hycor Corp., 29850 North Hwy. 41, Lake Bluff, Illinois, 60044. Fluid from the dewatering screen may be discharged through fluid line 138 back into slurry holding tank 124. As further illustrated by Fig. 1, slurry line 128 may be connected to a feedback line 140 controlled by a control valve 142. A control valve 143 may also be provided in line 128 at the inlet to separator 130. Valves 142 and 143 may be selectively operated to control the flow rate of slurry to separator device 130.

The initially separated slurry discharged from separator 130 may be further refined as by a coarse filter device 146. Coarse filter device 146 may comprise a device which filters the slurry down to a maximum particle size which is acceptable for use in blast spray water, e.g. a size of approximately 300 microns in diameter and may comprise an automatic backflush-type strainer such as that sold under the product designation model type WJR filter manufactured by R.P. Adams Co., 225 East Park Drive, Buffalo, New York, 14240-0963. Such a filter device includes a backflush assembly 147 which enables backflush cleaning of filter 146 and discharge of the backflush material through backflush line 148 into slurry holding tank 124. Coarse filter device 146 discharges coarsely refined slurry through lines 150 and 152 to water supply reservoir 125 in one operating state of the ACM removal assembly 10 in which a control valve 156 in a connected branch line 154 is closed and a control valve 155 in line 152 is open. In a second operating state of the ACM removal assembly, control valve 156 in branch line 154 is opened and control valve 155 in branch line 152 is closed. In this second operating state, the coarsely separated slurry is directed through first fine filter unit 158, line 160, and second fine filter unit 162 to provide a finely separated slurry which is discharged through line 164 into local municipal sewer drain 166 or the local earth/water environment. Fine filter units 158 and 162 are adapted to filter out particles down to a size which are; suitable for discharge into the environment. Current regulations typically specify this particle size to be on the order of 5 microns. n one specific embodiment of the invention, filter 158 comprises a Stranrite UF-180 filter unit manufactured by Stranrite Company of 190 Wallace Street, New Haven, Connecticut, 06513. Unit 158 is equipped with a 100-micron filter screen. Unit 162 may be identical to unit 158 except that it is equipped with a 5-micron filter screen.

In one preferred embodiment of the invention, slurry pump 122, slurry holding tank 124, slurry pump 126, separator device 130, dewatering device 132, asbestos holding tank 136, coarse filter device 146, fine filter units 158, 162, reservoir 25, spray water pump 26, air compressor 58, and vacuum pump 68 are all positioned externally of a building enclosure 11 from which asbestos-containing material is to be removed. Each of these components may be mounted in a unitary transport device 170 such as, for example, a truck trailer or the like, which may be conveniently pulled alongside a building from which ACM is to be removed. In operation, carriage 94 which supports housing assembly 30 and wet/dry vacuum unit 84 is moved to a selected building region, e.g. 180, from which exposed ACM is to be removed. An operator appropriately adjusts the position and elevation of pivot assemblies 96, 104, 110, etc., so as to urge the upper housing opening into sealing relationship with the selected building region. This is typically accomplished by compressing the bristles in bristle seal ring 46 slightly, e.g. 20%, against the exposed ACM 12. Next, a fluid spray blast from nozzles 16, 18, 20 is directed against the circumscribed ACM as the housing assembly 30 is slowly moved across the ceiling, preferably in a straight-line path in a series of sweeps in much the same manner, for example, that one would mow a lawn. The spray blast is provided through actuation of pump 26 such as by actuation of an electric motor associated therewith (not shown) or appropriate valves (not shown) associated therewith. As ACM is dislodged by the spray blast, it falls into housing 30 which is positioned immediately therebelow and is channeled downwardly therethrough by gravity and/or associated conveying device 40. Spent fluid from nozzles 16, 18, 20 is also captured in housing 30 and flows downwardly therethrough.

Before or simultaneously with the discharge of spray through nozzles 16, 18, 20, wet/dry vacuum assembly 84 is actuated to draw dislodged ACM and spent fluid from nozzles 16, 18, 20 into tank 88. An ACM slurry 90 is thus collected in tank 88 which is preferably removed therefrom in periodic intervals through use of pump 122. Pump 122 may be actuated manually or may be actuated automatically as by float valves or the like (not shown) provided in tank 88. Slurry 90 is pumped to holding tank 124 which is preferably located outside of building enclosure 11. Pump motor 126, which may also be operated either manually or through appropriate float valves or the like within tank 124, pumps slurry from tank 124 to separator device 130. Separator device 130 initially separates relatively large ACM particles 134 from a slurry which is discharged therefrom through line 144. Particles 134 are further separated from fluid clinging thereto by a dewatering unit 132 which returns the fluid thus separated from the particles to tank 124. The inflow of slurry to separator 130 may be controlled through control of valves 142 and 143 to enable continuous operation of pump 126 rather than intermittent operation thereof. Operation of control valves 142, 143 may be performed manually or through the use of float gauges (not shown) associated with tank 124, etc. Asbestos particles 134 are collected in container 136 which may be periodically sealed and removed from below units 134 and 132 or discharge to another sealable container. The initially refined slurry discharged from separator device 130 is filtered in coarse filter device 146 which discharges a coarsely filtered slurry into line 150. Line 150 communicates with branch lines 152 and 154. During normal operation of the spray blast for removal of ACM, control valve 155 in line 152 is open and control valve 156 in line 154 is closed. Thus, the coarsely separated slurry from line 150 passes through line 152 and returns to fluid reservoir 25 and is thus reused by the system to removingly blast ACM 12 from supporting building structure 14, for example, at a second building location 182. At the completion of the ACM spray blasting removal operation, the flow of water to nozzles 16, 18, 20 is terminated by closing control valve 33, and control valve 31 is simultaneously opened to enable pumping of water from reservoir 25 directly into slurry holding tank 124. After fluid flow to nozzles 16, 18, 20 has been terminated, motor 122 continues to operate until all of the slurry 90 in wet/dry vacuum tank 88 has been pumped to slurry holding tank 124. Approximately simultaneously with the closure of valve 33, valve 155 is closed and valve 156 is opened, thus allowing all of the coarsely separated slurry in line 150 to be directed through filter units 158, 162. The finely separated slurry discharged from fine filter 162 is typically discharged into a municipal sewer system. The collected ACM particles in collection tank 136 are appropriately sealingly enclosed, for example, in plastic bags, sealed containers or the like, and removed to appropriate ACM disposal sites.

During operation of spray nozzles 16, 18, 22, air provided under pressure to pressure ring 52 is discharged through outlet 54 to provide an encompassing inward air flow through bristle ring 46 which acts to prevent discharge of overspray or ACM particles through bristle seal 46. At the same time, a vacuum is also applied to vacuum ring 62 which provides a flow of air from pressure ring opening 54 to vacuum ring opening 64 which tends to capture any overspray or particles which may have initially escaped through bristle seal 46. Thus, the inward air flow through bristle seal 46 which is provided by the vacuum developed by wet/dry vacuum assembly 84 is further enhanced by pressurized air flow from pressure ring 52, and any escaping particles from the bristle seal which are not redirected through the bristle seal back into housing 30 are carried by the air flow from pressure ring 52 into outer vacuum ring 62. Further pressure rings (not shown) and further vacuum rings (not shown) may also be provided in alternating concentric relationship with rings 52 and 62 to provide further annular air seals to further prevent overspray and particle discharge into the atmosphere surrounding housing 30.

Although a housing having a horizontally disposed top opening with square-shaped opening configuration has been described for removal of ACM from a ceiling region of a building, it will be appreciated that housing openings having various other configurations may be provided for engaging different ACM-covered surfaces of a building. For example, an arcuate, vertically disposed housing opening (not shown) could be provided for removing ACM from cylindrical pipes, wedge-shaped housing openings (not shown) could be provided for removing ACM from corner regions of walls and ceilings, etc. It will also be appreciated that multiple housing units might be employed and associated with a single or multiple collection vacuum sources, and such housing units might be mounted on various different types of portable assemblies which may be hand-carried assemblies as well as carriage-type assemblies, etc.

An alternative carriage assembly 200 for supporting the above described nozzle means, housing means 30, and wet/dry vacuum assembly and tank 84, 88 is shown in Fig. 5. The carriage assembly 200 includes a wheeled platform 202 having a plurality of vertical post members 204, 206, etc. fixedly mounted thereon. A plurality of lateral members 208, etc. and longitudinal members 210, etc. are fixedly attached to the vertical post members to form a generally parallelepiped shaped frame 211.

A plurality of conventional jacks 212, 214, etc. are mounted on pivot arms 216, 218, etc. which are pivotally mounted on the frame. The jacks/pivot arm assemblies may be used to temporarily secure the wheeled carriage at a fixed location in an associated building from which ACM is to be removed.

A longitudinally extending beam 222 is longitudinally adjustably mounted as by beam clamping units 224, 226 to an upper portion of frame 211. A rodless air/hydraulic cylinder unit 228, such as that manufactured by Festo Corporation of 395 Moreland Road, Hauppauge, New York, 11788, is translatably mounted on an elongate shaft 230 which is, in turn, fixedly mounted on longitudinally extending beam 222. The cylinder unit 228 is operatively connected to a compressed air/hydraulic fluid supply source (not shown) and is selectively positionable along the shaft 230 through conventional air/hydraulic controls (not shown) . The cylinder unit is fixedly attached to a longitudinal slider unit 232 which is slidably supported on beam 222. Thus the longitudinal position of the slider unit 232 may be controlled by selective actuation of cylinder unit 228.

A laterally extending beam 234 is laterally displaceably mounted on slider unit 232. A second rodless cylinder unit 236 is fixedly mounted on slider unit 232 and is translatably mounted on a laterally extending shaft 238 which is, in turn, fixedly mounted on laterally extending beam 234. Beam 234 is laterally displaceable with respect to slider unit 232 through selective actuation of cylinder unit 236.

Nozzle supporting housing 30 is supported at one end of laterally extending beam 234. Thus housing 234 may be selectively positioned within a rectangular area defined by the reach of beams 222 and 234 through actuation of cylinder units 228, 232. In addition beam 222 may be supported on members which are vertically displaceable with respect to fixed frame 211 such that housing 234 may be selectively raised and lowered to place it in engagement with the building ceiling or to remove it from such engagement.

An alternate embodiment of an ACM removal system is illustrated in Fig. 6.

A nozzle assembly 301 is provided for directing a pressurized fluid 302 such as water against ACM 303 which is supported on a building structure. This nozzle assembly 301 may be identical to the nozzle assembly described above with reference to Figs. 1-4.

A vacuum unit 304 such as a wet/dry hepavacuum unit capable of developing a 95 inch water column negative pressure air flow at approximately 200 CFM is provided for transporting dislodged ACM 303 and spent fluid 302 to a collection tank 310. Exhaust air 306 from the vacuum is filtered, as indicated at 308 and discharged to the atmosphere. The collection tank 310 receives the dislodged ACM and spent fluid forming to form an ACM slurry 312 therein. The collection tank may be a 55 gal. barrel. A collection tank pump 314, such as a 10 GPM clog resistant impeller type pump is provided for pumping the ACM slurry 312 from the collection tank to a first separation assembly 316.

The first separation assembly 316 removes ACM particles larger than a first predetermined particle size, e.g. 0.010 inches in diameter, from the ACM slurry. The first separation assembly may comprise wedge wire scalping screen 318 inclined at an angle, e.g. 45°, and may further comprise a dewatering unit such as a wringer roller 320 mounted at the bottom of screen 318 which compresses the oversize particles before depositing them in a first hopper 322.

After removal of the oversize particles by the first separation assembly 316 the remainder of the ACM slurry passes through a first sump reservoir 326. The first sump reservoir receives and settlingly collects ACM slurry from both the first separation assembly 316 and from a second separation assembly 334. A first weir 328 directs ACM slurry overflowing from the first sump reservoir into a second sump reservoir 340. A first sump pump 330 pumps ACM slurry from a lower portion of the first sump reservoir 326 to the second separation assembly 334. The first sump pump may be a 25 GPM pump.

The second separation assembly removes ACM particles larger than a second predetermined particle size, e.g. 50 microns in diameter, from the ACM slurry pumped thereto by the first sump pump 330. The second separation assembly may comprise a centrifuge type separator such as a Krebs Cyclone Model V2 manufactured by Krebs Engineers having a business address of 1205 Cryster Drive, Menlo Park, California, 94025.

The second sump reservoir receives and settlingly collects the ACM slurry overflowing the first sump reservoir 326 and also ACM slurry discharged from a third separation assembly 344.

A second sump pump which may be a 25 GPM pump^pumps ACM slurry from a lower portion of the second sump reservoir 340 to the third separation assembly.

The third separation assembly removes particles greater than a third predetermined particle size, e.g. 5 microns inches in diameter, from the ACM slurry pumped thereto by the second sump pump 342 and discharges the ACM slurry into the second sump reservoir 340. The third separation assembly may comprise a pair of bag strainers such as those manufactured as Strainrite model UF 1-180 by Strainrite having a business address of 190 Wallace Street, New Haven, Connecticut, 06513.

A second weir 350 directs ACM slurry overflowing the second sump reservoir into a third sump reservoir 352. The third sump reservoir receives and collects the ACM slurry overflowing the second sump reservoir and also make-up water from a make up water supply 354. A third sump pump pumps ACM slurry from a lower portion of the third sump reservoir 352 to the nozzle assembly supplying fluid under pressure to thereto.

A float valve 356 disposed in the third sump reservoir acts as a level control device for initiating a flow of make-up water thereto when the liquid level in the third sump reservoir falls below a predetermined level.

The discharge from the third separation assembly 344 may be sent through a two way valve 358 which directs the slurry flow therefrom to the third sump reservoir 352 during normal operation of the system. However at the end of operations the valve is switched such that the flow from third separation assembly 344 is directed to a drain. In one embodiment of the invention in which the filtration provided by assembly 344 is not sufficiently fine for drain discharge a separate final filtration unit 362, which may be of the same type as unit 344, is provided between valve 358 and the drain which filters out particles smaller than a fourth predetermined particle size, e.g. 3 microns in diameter.

A strainer unit 364 may be provided in the flow line between pump 356 and the nozzle assembly as a fail safe device for catching any particles of a size which might clog the nozzle assembly.

One preferred embodiment of a sump assembly 400 which may be used for practicing the invention will now be described with reference to Fig.7. The sump assembly 400 comprises four outer vertical sidewalls 402, 404, 406, 408 which are joined to one another and to a rectangular bottom wall 410 by welding or other conventional means to provide a parallelepiped shaped structure. A first vertical interior wall 412 is sealingly attached to sidewalls 402 and 406 and bottom wall 410. A second vertical interior wall 414 is sealingly attached to sidewall 404, first interior wall 412, and bottom wall 410. The interior walls thus divide the sump assembly 400 into first, second, and third separate reservoirs 326, 340, and 352.

First and second weir cut-outs 416, 418 are provided in portions of the interior walls dividing the first reservoir 326 from the second reservoir 340 and dividing the second reservoir from the third reservoir 352, respectively. The weir cut-outs are provided at the top of each interior wall progressively reduced in elevation, e.g. the second weir cutout 418 is 1 inch lower than the first weir cutout 416, such that the liquid in the three separate reservoirs remain in communication so long as the liquid level in the sump assembly is at or above the level of all the weir cut-outs.

First and second vertical partition 422, 424 are provided in first and second sump reservoirs 326, 340 dividing the first reservoir into first and second chambers 430, 432, and dividing the second reservoir into first and second chambers 434, 436. Each partition extends from the top of the sump assembly 400 to a position above the elevation of the bottom wall 410 such that chamber 430 is in fluid communication with chamber 432 and chamber 434 is in fluid communication with chamber 436 at the lower portions thereof.

A sloping bottom panel 442 is provided in sump reservoir 326 which extends from interior wall 414 to the intersection of side wall 402 and bottom wall 410. The panel 442 may slope downwardly at an angle of approximately 25° and may be spaced from the bottom of vertical panel 422 approximately 2 inches. Due to the slope of panel 442, particles settling thereon in chamber 432 tend to migrate into chamber 430. The second sump reservoir 340 is provided with a similar bottom panel 444 which slopes downwardly from wall 412 to the intersection of side wall 404 and bottom wall 410 thus causing particles settling thereon in chamber 436 to migrate into chamber 434.

The ACM slurry discharged from the first separation assembly 316 is fed into first reservoir first chamber 430 as shown at 452. The ACM slurry discharged from the second separation assembly 334 is fed into the first reservoir second chamber 432 as shown at 454. The ACM slurry discharged from the third separation assembly 344 is fed into second reservoir second chamber 436 as shown at 456. Fresh make-up water flow initiated by float valve 356, Fig. 6, is fed into the third reservoir 352 as shown at 458.

Discharge orifices 462, 464, 466 which communicate with pumps 330, 342, 354, respectively are provided in lower portions of chambers 430, 434, and reservoir 352, respectively.

In one preferred embodiment of the invention each of the sump reservoirs 326, 340, 352 has a capacity of approximately 40 gallons. The conduit from collection tank 310 to first separation assembly may be 10 ft. long and 1.25 in. in diameter; the conduit from the sump assembly 400 to the second separation assembly 334 may be 10 ft. long and 1.5 in. in diameter with a return conduit of the same dimensions; the conduit from the sump assembly 400 to the third separation assembly 344 may be 10 ft. long and 1.5 in. in diameter with a return conduit of the same dimensions; the conduit from the sump assembly pump 353 to the spray nozzle assembly 301 may be 10 ft. long and 0.5 in. in diameter.

In an alternative embodiment of the ACM removal system 300 shown in Fig.6 the nozzle assembly 301 is eliminated and the return liquid from sump reservoir 350 is provided directly to the collection tank 310 as indicated in phantom at 366. In this embodiment of the system ACM debris may be deposited in the collection tank 310 as by a conventional wet/dry vacuum unit or by other means such as by shoveling ACM debris from the floor of the associated building and manually depositing it in collection tank 310. Depending upon the size of the ACM material being deposited in tank 310 it may be desireable to provide an ACM shredding device 368 such as an auger screw or any other device capable of reducing the ACM to a maximum particle size, e.g. 0.5 in. in diameter, suitable for slurry transport. The shredding device may be incorporated in the collection tank 310 or may be separate therefrom.

As with the previously described embodiments of the invention it will be understood that in the embodiment of Fig. 7 that ACM particles collected in hoppers 322, 338, and also in collection bags (not shown) associated with separation assembly 344, may be collected in plastic trash bags or the like and taken to an approved dumping site for disposal.

A particular advantage of the ACM removal assembly shown in Fig. 6 which is provided by the sump assembly 400 is that the flow volumes of the various separation assemblies need not be precisely matched for proper operation. A further advantage is that the settling action which takes place in each of the sump reservoirs acts as a further separation means.

Although the invention has been specifically described with reference to ACM removal it will of course be appreciated that the invention may also be employed to remove building debris other than ACM.

Thus, while an illustrative and presently preferred embodiment of the invention has been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed and that the appended claims are intended to be construed to include such variations except insofar as limited by the prior art.

Claims

WHAT IS CLAIMED IS:

1. An ACM removal assembly comprising: a) nozzle means for directing a pressurized fluid against ACM which is supported on a building structure for dislodging the ACM; b) pressurized fluid supply means operably connected to said nozzle means for supplying fluid under pressure thereto; and c) housing means for supporting said nozzle means therein and for capturingly receiving spent fluid and dislodged ACM.

2. The invention of claim 1 further comprising material handing and separating means operably connected to said housing means for receiving combined spent fluid and dislodged ACM from said housing means for separating said spent fluid from said dislodged ACM.

3. The invention of claim 2 wherein at least a portion of said fluid supplied to said nozzle means by said pressurized fluid supply means is separated spent fluid received from said material handling and separating means.

4. The invention of claim 1 further comprising: flexible mechanical seal means for forming a seal at an interface between said housing and a building region from which ACM is to be removed for inhibiting discharge of waste fluid and dislodged ACM into the environment outside said housing means.

5. The invention of claim 4, said flexible mechanical seal means being displaceable across the surface of said interfacing building region without disrupting said seal between said housing means and the interfacing building region.

6. The invention of claim 5, said housing means comprising a first opening therein, said flexible mechanical seal means comprising flexible bristles mounted about the periphery of said first opening in said housing means.

7. The invention of claim 6 further comprising: first vacuum means operatively connected with said housing means for producing a below atmospheric air pressure therein whereby an inwardly directed airflow is provided about the periphery of said first opening means; said inwardly directed peripheral airflow passing through said bristles mounted about said first opening whereby fluid overspray from said nozzle means is directed inwardly by said inward peripheral airflow.

8. The invention of claim 7 further comprising: first annular air seal means for facilitating recapture of overspray from said nozzle means which penetrates said mechanical seal means comprising positive pressure air supply means positioned in circumscribing relationship about said housing means first opening.

9. The invention of claim 8 further comprising: second annular air seal means for facilitating recapture of overspray from said nozzle means penetrating said mechanical seal means and said first annular air seal means, said second annular air seal means comprising second vacuum means positioned in circumscribing relationship about said first annular air seal means.

10. The invention of claim 7 further comprising: first vacuum monitor means operatively associated with said housing means for monitoring the relative air pressure therein and for generating a control signal indicative thereof; and shutoff valve means operatively associated with said nozzle means and response to said monitor means control signal for terminating the flow of fluid to said nozzle means in response to the air pressure in said housing means reaching a predetermined value.

11. The invention of claim 10 further comprising blowoff valve means operatively associated with said housing means for releasing pressure within said housing means at a predetermined pressure value.

12. The invention of claim 2 further comprising conveying means mounted within said housing means for conveying combined ACM and waste fluid from said housing means to said material handling and separating means.

13. The invention of claim 5 further comprising housing support means for supporting said housing means, comprising: a) biasing means for axially urging said housing means toward the building region from which ACM is to be removed for maintaining a seal thereagainst; b) lateral displacement means for laterally displacing said housing means relative a building region from which ACM has been removed and toward a building region from which material is to be removed.

14. The invention of claim 2, said material handling and separating means comprising: a) first ACM removal means for removing ACM particles larger than a predetermined first particle size from said combined ACM and spent fluid and for discharging a coarsely refined ACM slurry; b) valve means in fluid communication with said first ACM removal means for directing said coarsely refined ACM slurry to said pressurized fluid supply means during a first operating state thereof and for directing said coarsely refined ACM slurry to a second ACM removal means during a second operating state thereof; c) second ACM removal means for receiving said coarsely refined ACM slurry and for removing ACM particles larger than a second predetermined particle size from said coarsely refined ACM slurry and for discharging a finely refined ACM slurry therefrom; and d) drain means for receiving said finely refined ACM slurry and for discharging said finely refined ACM slurry into the local sewer system.

15. A method for removing ACM from a building structure comprising: a) sealingly circumscribing a building region having exposed ACM with an ACM containment apparatus; b) removing ACM from the circumscribed building region with a fluid spray blast; c) combiningly capturing dislodged ACM and spent fluid from the spray blast in the containment apparatus; d) separating a portion of the ACM from the combined ACM and spent fluid; and e) reusing the coarsely separated fluid to remove ACM from the building.

16. The invention of claim 15 including the further steps of: a) fine-filtering the coarsely separated fluid; b) discharging the finely filtered fluid into the local sewage system; and c) transporting the separated ACM to a solid waste disposal facility.

17. An ACM removal assembly comprising: a) nozzle means for directing a pressurized fluid against ACM which is supported on a building structure for dislodging the ACM; b) pressurized fluid supply means operably connected to said nozzle means for supplying fluid under pressure thereto; c) housing means for supporting said nozzle means therein and for capturingly receiving spent fluid and dislodged ACM; and d) material handing and separating means operably connected to said housing means for receiving combined spent fluid and dislodged ACM from said housing means for separating said spent fluid from said dislodged ACM; said material handling and separating means comprising coarse separating means for coarsely separating said spent fluid from said dislodged ACM and fluid return means for returning coarsely separated fluid to said pressurized fluid supply means.

18. The invention of claim 17, said material handling and separating means comprising fine separating means for receiving coarsely separated fluid from said coarse separating means and for finely separating ACM therefrom.

19. An ACM removal system comprising: nozzle means for directing a pressurized fluid against ACM which is supported on a building structure for dislodging the ACM; vacuum means for transporting dislodged ACM and spent fluid to a first collection tank means; collection tank means for receiving said dislodged ACM and spent fluid whereby an ACM slurry is formed and collected therein; collection tank pump means for pumping said ACM slurry from said collection tank means to a first separation means; first separation means for removing ACM particles larger than a first predetermined particle size from said ACM slurry; first sump reservoir means for receiving and settlingly collecting ACM slurry from said first separation means and ACM slurry from a second separation means therein; first weir means for directing ACM slurry overflowing said first sump reservoir means into a second sump reservoir means; first sump pump means for pumping ACM slurry from said first sump reservoir means to said second separation means; second separation means for removing ACM particles larger than a second predetermined particle size from said ACM slurry pumped thereto by said first sump pump means; second sump reservoir means for receiving and settlingly collecting said ACM slurry overflowing said first sump reservoir means and ACM slurry discharged from a third separation means therein; second sump pump means for pumping ACM slurry from said second sump reservoir means to said third separation means; third separation means for removing particles greater than a third predetermined particle size from said ACM slurry pumped thereto by said second sump pump means and for discharging said ACM slurry into said second sump reservoir means; second weir means for directing ACM slurry overflowing said second sump reservoir means into a third sump reservoir means; third sump reservoir means for receiving and collecting said ACM slurry overflowing said second sump reservoir means and make-up water from a make up water supply therein; third sump pump means for pumping ACM slurry from said third sump reservoir means to said nozzle means for supplying fluid under pressure to said nozzle means; valve means operatively associated with said third sump reservoir means for providing a flow of said make-up water thereto when the liquid level in said third sump reservoir means falls below a predetermined level.

20. The invention of claim 19 wherein said second weir means is positioned at a lower elevation than said first weir means.

21. The invention of claim 20 wherein said first sump reservoir means comprises first and second chambers separated at upper portions thereof by a common partition and being in fluid communication at lower portions thereof.

22. The invention of claim 21 said first sump reservoir further comprising a bottom wall sloping upwardly from said first chamber to said second chamber thereof whereby particles settling on said bottom wall are gravity fed into said first chamber.

23. The invention of claim 22 said first weir being provided in said first sump pump reservoir second chamber.

24. The invention of claim 23 said first sump pump means receiving ACM slurry through a discharge port in said first sump pump reservoir first chamber.

25. The invention of claim 24 said ACM slurry discharged from said first separation means being fed into said first sump pump reservoir first chamber.

26. The invention of claim 25 said ACM slurry discharged from said second separation means being fed into said first sump pump reservoir second chamber.

27. The invention of claim 20 wherein said second sump reservoir means comprises first and second chambers separated at upper portions thereof by a common partition and being in fluid communication at lower portions thereof.

28. The invention of claim 27 said second sump reservoir further comprising a bottom wall sloping upwardly from said first chamber to said second chamber thereof whereby particles settling on said bottom wall are gravity fed into said first chamber.

29. The invention of claim 28 said second weir being provided in said second sump pump reservoir second chamber.

30. The invention of claim 29 said second sump pump means receiving ACM slurry through a discharge port in said second sump reservoir first chamber.

31. The invention of claim 30 said ACM slurry overflowing from said first sump reservoir means being fed into said second sump pump reservoir first chamber.

32. The invention of claim 31 said ACM slurry discharged from said third separation means being fed into said first sump pump reservoir second chamber.

33. The invention of claim 19 said vacuum means comprising housing means for supporting said nozzle means thereon and for initially capturingly receiving said spent fluid and dislodged ACM therein.

34. The invention of claim 19 said vacuum means comprising filter means for filtering air discharged from said collection tank means.

35. The invention of claim 19 wherein said first separation means comprises inclined screen means for separating ACM particles larger than the screen mesh thereof and for rollingly discharging particles collected on top said inclined screen means into a first hopper.

36. The invention of claim 35 further comprising dewatering means operatively associated with said inclined screen means for removing water from said ACM particles removed by said screen means and for discharging said removed water into said first sump reservoir means.

37. The invention of claim 19 wherein said second separation means comprises centrifuge means for centrifically removing ACM particles from said ACM slurry.

38. The invention of claim 19 wherein said third separation means comprises filter means for filteringly removing ACM particles from said ACM slurry.

39. The invention of claim 19 further comprising two way valve means for directing ACM slurry from said third separation means to said second sump reservoir means during a normal operating state and to a drain means during an end of operation operating state.

40. The invention of claim 39 further comprising a final filter means disposed between said two way valve and said drain means for finally filtering the ACM slurry being sent to the drain for removing particles larger than a forth predetermined particle size.

41. The invention of claim 33 further comprising means for displaceably supporting said housing comprising: first translation means attached tp«said housing means for linearly translating said housing means along a first translation axis;

.second translation means attached to said first translation means for translating said first translation means along a second translation axis extending transversely of said first translation axis; wheeled carriage means for supporting said second translation means thereon; jack means displaceably mounted on said carriage means for stably securing said wheeled carriage means to an associated support structure.

42. An ACM removal system comprising: collection tank means for receiving and mixing dislodged ACM and a transport liquid whereby an ACM slurry is formed and collected therein; collection tank pump means for pumping said ACM slurry from said collection tank means to a first separation means; first separation means for removing ACM particles larger than a first predetermined particle size from said ACM slurry; first sump reservoir means for receiving and settlingly collecting ACM slurry from said first separation means and ACM slurry from a second separation means therein; first weir means for directing ACM slurry overflowing said first sump reservoir means into a second sump reservoir means; first sump pump means for pumping ACM slurry from said first sump reservoir means to said second separation means; second separation means for removing ACM particles larger than a second predetermined particle size from said ACM slurry pumped thereto by said first sump pump means; second sump reservoir means for receiving and settlingly collecting said ACM slurry overflowing said first sump reservoir means and ACM slurry discharged from a third separation means therein; second sump pump means for pumping ACM slurry from said second sump reservoir means to said third separation means; third separation means for removing particles greater than a third predetermined particle size from said ACM slurry pumped thereto by said second sump pump means and for discharging said ACM slurry into said second sump reservoir means; second weir means for directing ACM slurry overflowing said second sump reservoir means into a third sump reservoir means; third sump reservoir means for receiving and collecting said ACM slurry overflowing said second sump reservoir means and make-up water from a make up water supply therein; third sump pump means for pumping ACM slurry from said third sump reservoir means to said collection tank means for supplying transport liquid thereto; valve means operatively associated with said third sump reservoir means for providing a flow of said make-up water thereto when the liquid level in said third sump reservoir means falls below a predetermined level.

43. An ACM removal system comprising: a) collection tank means for mixingly receiving a flow of transport liquid and dislodged ACM therein for forming an ACM slurry; b) collection tank pump means for pumping said ACM slurry to a separation assembly; c) said separation assembly comprising: i) sump means having a progressively weir linked series of separate sump compartments which overflowingly communicate through a weir structure for collecting progressively more refined ACM slurry in each of said separate chambers in said progressive series; ii) a plurality of separation loop means associated with different ones of said separate sump compartments, each separation loop means comprising:

A) separation means for separating ACM particles larger than a predetermined size from ACM slurry received thereby;

B) loop pump means for pumping ACM through a closed loop comprising said separation means and said associated sump compartment; iii) liquid supply pump means for pumping liquid from said sump chamber having the most refined ACM slurry therein to said collection tank means; and iv) make up liquid supply means for supplying make up liquid to said sump means.

44. A building debris removal system comprising: a) collection tank means for mixingly receiving a flow of transport liquid and dislodged building debris therein for forming an building debris slurry; b) collection tank pump means for pumping said building debris slurry to a separation assembly; c) said separation assembly comprising: i) sump means having a progressively weir linked series of separate sump compartments which overflowingly communicate through a weir structure for collecting progressively more refined building debris slurry in each of said separate chambers in said progressive series; ii) a plurality of separation loop means associated with different ones of said separate sump compartments, each separation loop means comprising:

A) separation means for separating building debris particles larger than a predetermined size from building debris slurry received thereby;

B) loop pump means for pumping building debris through a closed loop comprising said separation means and said associated sump compartment; iii) liquid supply pump means for pumping liquid from said sump chamber having the most refined building debris slurry therein to said collection tank means; and iv) make up liquid supply means for supplying make up liquid to said sump means.

45. A building debris removal system comprising: collection tank means for receiving and mixing dislodged building debris and a transport liquid whereby an building debris slurry is formed and collected therein; collection tank pump means for pumping said building debris slurry from said collection tank means to a first separation means; first separation means for removing building debris particles larger than a first predetermined particle size from said building debris slurry; first sump reservoir means for receiving and settlingly collecting building debris slurry from said first separation means and building debris slurry from a second separation means therein; first weir means for directing building debris slurry overflowing said first sump reservoir means into a second sump reservoir means; first sump pump means for pumping building debris slurry from said first sump reservoir means to said second separation means; second separation means for removing building debris particles larger than a second predetermined particle size from said building debris slurry pumped thereto by said first sump pump means; second sump reservoir means for receiving and settlingly collecting said building debris slurry overflowing said first sump reservoir means and building debris slurry discharged from a third separation means therein; second sump pump means for pumping building debris slurry from said second sump reservoir means to said third separation means; third separation means for removing particles greater than a third predetermined particle size from said building debris slurry pumped thereto by said second sump pump means and for discharging said building debris slurry into said second sump reservoir means; second weir means for directing building debris slurry overflowing said second sump reservoir means into a third sump reservoir means; third sump reservoir means for receiving and collecting said building debris slurry overflowing said second sump reservoir means and make-up water from a make up water supply therein; third sump pump means for pumping building debris slurry from said third sump reservoir means to said collection tank means for supplying transport liquid thereto; valve means operatively associated with said third sump reservoir means for providing a flow of said make-up water thereto when the liquid level in said third sump reservoir means falls below a predetermined level.

46. A building debris removal system comprising: . nozzle means for directing a pressurized fluid against building debris which is supported on a building structure for dislodging the building debris; vacuum means for transporting dislodged building debris and spent fluid to a first collection tank means; collection tank means for receiving said dislodged building debris and spent fluid whereby a building debris slurry is formed and collected therein; collection tank pump means for pumping said building debris slurry from said collection tank means to a first separation means; first separation means for removing building debris particles larger than a first predetermined particle size from said building debris slurry; first sump reservoir means for receiving and settlingly collecting building debris slurry from said first separation means and building debris slurry from a second separation means therein; first weir means for directing building debris slurry overflowing said first sump reservoir means into a second sump reservoir means; first sump pump means for pumping building debris slurry from said first sump reservoir means to said second separation means; second separation means for removing building debris particles larger than a second predetermined particle size from said building debris slurry pumped thereto by said first sump pump means; second sump reservoir means for receiving and settlingly collecting said building debris slurry overflowing said first sump reservoir means and building debris slurry discharged from a third separation means therein; second sump pump means for pumping building debris slurry from said second sump reservoir means to said third separation means; third separation means for removing particles greater than a third predetermined particle size from said building debris slurry pumped thereto by said second sump pump means and for discharging said building debris slurry into said second sump reservoir means; second weir means for directing building debris slurry overflowing said second sump reservoir means into a third sump reservoir means; third sump reservoir means for receiving and collecting said building debris slurry overflowing said second sump reservoir means and make-up water from a make up water supply therein; third sump pump means for pumping building debris slurry from said third sump reservoir means to said nozzle means for supplying fluid under pressure to said nozzle means; valve means operatively associated with said third sump reservoir means for providing a flow of said make-up water thereto when the liquid level in said third sump reservoir means falls below a predetermined level.

47. A method of removing building debris from a work site comprising: a) mixing transport liquid and dislodged building debris in a collection tank to form a building debris slurry; b) pumping said building debris slurry to a first compartment of a sump having a progressively weir linked series of separate sump compartments which overflowingly communicate through a weir structure; c) pumping said building debris slurry from a first compartment of said sump through a first separation device, removing particles greater than a first particle size from said slurry at said first separation device, and returning the remainder of said slurry to said first compartment of said sump; d) pumping said building debris slurry from a second compartment of said sump through a second separation device, removing particles greater than a second particle size from said slurry at said second separation device, and returning the remainder of said slurry to said second compartment of said sump; e) pumping said building debris slurry from a last compartment in said series of compartments of said sump to said collection tank.