System for removing asbestos from structures

A system and process for removing hazardous or toxic particulate materials from surfaces includes all components necessary for safe removal of the material in a van body that can be moved easily from one site to another. The system includes mechanism for sealing of selected areas, with tubing connecting the selected sealed areas to a separator chamber in the van body. Air pressure is lowered within the sealed enclosed area and airflow is maintained through the tube to the separator chamber. Fluidic carrier jets may also be directed within the tube toward the separator chamber. Particulate materials can be removed from the surface within the enclosure and deposited into the tube where it flows in an air and fluid carrier stream to the separator chamber. There, larger particulates are allowed to drop into a collection tank. Remaining particulate materials are filtered by a high efficiency particulate absolute filter until the air is safe to be discharged into the atmosphere. Airflow and pressure differential is produced by one or more of a series of valved fan units near a discharge end of the chamber. An auxiliary airflow tube and return air (make-up air) tube can also be connected between the chamber and enclosure.

FIELD OF THE INVENTION 
The present invention relates to safe removal of hazardous, toxic or 
nuisance particulate materials and other dispersible matter, organic or 
inorganic, or admixtures sorbed or adsorbed. 
BACKGROUND OF THE INVENTION 
Existing methods for removing hazardous or toxic materials involves very 
tedious and expensive procedures. For example, a room containing dangerous 
asbestos materials must be first sealed off. Workers wearing protective 
clothing then remove the materials within the sealed room, placing it 
within plastic bags. The bags are then moved to a disposal site. 
This process is very slow and not without hazards. Even double lining for 
the bag containers will not prevent accidental breakage at which time the 
materials included therein may be released to the atmosphere. Furthermore, 
the room must be opened then resealed as workers enter and leave the area. 
Careful cleaning procedures must also be followed after the asbestos has 
been removed. 
The need for removal of asbestos from structures is often foregone because 
the resources necessary to fund the appropriate conventional removal 
procedures are lacking. Many structures therefore remain with the asbestos 
problem or must be abandoned until sufficient funding and competent 
removal contractors can be obtained to correct difficulty. 
Similar predicaments are experienced with other dangerous or nuisance 
materials where safe, yet efficient, removal is desired. 
An urgent need therefore remains for removal equipment that will facilitate 
safe and complete removal of asbestos and other hazardous, toxic, or 
nuisance materials.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
In compliance with the constitutional purpose of the Patent Laws "to 
promote the progress of science and useful arts" (Article 1, Section 8), 
applicant submits the following disclosure of the invention. 
For purposes of this disclosure, the term "materials" and "particulates" as 
used herein should be understood to mean any dispersible hazardous, toxic, 
or nuisance matter which can be organic or inorganic, or admixtures sorbed 
or adsorbed upon each other. By way of example only, the present 
description will deal primarily with removal of asbestos materials from 
surfaces, usually within structures. With the above definition, however, 
it should be well understood that the present process and system may be 
useful in the safe removal of many other forms of "particulates" or 
"materials." An exemplary list may include, but is not limited to: urea 
formaldehyde, insulation materials, dioxins, coal dust, arsenic, 
silicates, grain dust, wood dust, PCB's (polychlorinated biphenol), etc. 
Given the above understanding, the process and system exemplified herein 
may be provided for the removal of such materials as generally indicated 
graphically at 10 in FIG. 1 from an existing surface 11. Asbestos, as an 
example of such material 10, requiring removal is typically found in 
structures where pipes, ducting, or ceiling insulation, etc. has been 
accomplished using material including asbestos fibers. Removal of the 
loose particulate materials becomes necessary to avoid serious potential 
health hazards. The present system affords economical and relatively quick 
removal of the materials in a safe and effective manner. 
Material 10 removed from the surface 11 is delivered by an air collection 
system to a collection tank 12 within a portable wheel-supported van body 
13. The body 13 can be selectively moved by truck or other towing vehicle 
from one site to another and to appropriate authorized disposal sites 
where the sealed collector tank 12 can be emptied. 
An important aspect of the present system is an enclosure means shown 
generally in FIG. 1 and in more detail in FIG. 4. The enclosure means 15 
is securable to the surface 11 for effectively enclosing an area about the 
particulate 10 to be removed. The form of the enclosure means 15 shown in 
FIGS. 1 and 4 may vary according to need. For example, the enclosure means 
may take the form of the room or structure shown in FIGS. 1 and 4. 
Alternatively, it may simply be an appropriate sealing arrangement (not 
shown) where the materials are to be removed from a surface area in or 
outside of a structure. 
The enclosure means 15 exemplified in FIGS. 1 and 4 is defined by five 
flexible sides that may be foldable. One open side 17 is preferably open 
and securable to the structure. The top side, as shown in FIGS. 1 and 4, 
is provided with a rim 18 for substantially sealing the enclosure about 
the confined area. The open end 17 could also be situated along one of the 
remaining sides depending upon the location of the material being removed. 
A bottom 19 of the enclosure may be provided with an appropriate grate or 
flooring to support workers therein. The side walls 15 are preferably 
formed of a flexible material that may be transparent or translucent and 
supported on an expandable frame 20. The entire enclosure can be supported 
on a standard scaffold or lift mechanism 22. 
The enclosure shown may be effectively used to substantially seal an area 
for removal of materials from overhead areas, floors or walls, such as, 
but not limited to, piping, air conditioning ducts, ceiling tiles and 
boiler lines. 
Provision may be made for receiving a fluid such as water from an outside 
supply 21 through one of the flexible walls of the enclosure means when 
desired. For example, the outside fluid source may be used to supply water 
within the enclosure to wet asbestos materials. The water may be mixed with 
a saturant and sprayed onto the material before removal. The wetted 
asbestos may then be removed from the structure within the perimeter of 
the enclosure. 
Danger of particulates escaping the enclosure is minimized by maintaining a 
negative pressure within the enclosure means. That is to say, the air 
pressure within the enclosure will be maintained lower than the ambient 
pressure surrounding the enclosure. Any air seepage will therefore be in 
an inward direction into the enclosure. Air will not be allowed to seep 
out into the surrounding area. Any unsettled, airborne particulates will 
therefore remain within the enclosed area. This pressure differential is 
maintained by apparatus that will be described in greater detail below. 
The enclosure means may be provided with several fittings for connection to 
tubes leading to the portable wheel-supported van 13. A fitting 23, for 
example, is provided for mounting a return air duct that supplies fresh 
air or recycled air in a closed circuit with the present system to the 
enclosure means. A fitting 24 is also provided for an auxiliary air tube 
used for drawing air and particulates to the van. Another provision may be 
made in the form of a funnel 25 formed along the floor or enclosure bottom 
19. The funnel is upwardly open to receive materials removed from the 
structure within the perimeter of the enclosure means 15. 
For solid materials, the funnel 25 may lead to a grinder means 27 that is 
shown in FIGS. 4 and 5. The grinder means 27 may be attached to the funnel 
25 for receiving materials and for grinding them into small, easily moved 
particulates. 
The grinder means may include a hollow tubular structure with a rubber 
splashback door 28 at an upward end thereof. This upward end is attachable 
and sealable to the funnel 25 for receiving the removed materials. The 
rubber splashback door will allow relatively free passage of the material 
as it is dropped into the grinder but will prevent the particulates from 
being thrown back upwardly by the grinding mechanisms below. 
The removed particulates may be ground or comminuted between a bladed rotor 
29 and rigid stators 30 mounted within the tubular support. A drive motor 
31 is supplied outside the grinder tube for driving the rotor 29. It has 
been found that a 1.5 hp. motor rotating the grinder at approximately 
3,600 rpm will function adequately to comminute any received materials to 
particle sizes easily transported in the closed system to the waiting van. 
The rotors operate with a hammer-mill effect to comminute the material and 
discharge the resulting particles downwardly to a hollow tube 34 extending 
from an intake end 35 to a discharge end 36 connected to the van 13. The 
rotors will also produce an auxiliary airflow due to the rotating blades 
into the tube 34, assisting the airflow produced via the air collection 
system described below. 
As an alternative, the grinder means 27 may provide a somewhat reduced 
scale from that shown in FIGS. 4 and 5 of the drawings to facilitate 
handheld use. Such an arrangement might be coupled with the larger grinder 
mechanisms shown, or could be used alone and directly connected to the 
hollow tube 34 by an appropriate flexible tube (not shown). Common vacuum 
heads can be used, branching into tube 34, depending on the nature of 
materials to be removed. Such branch lines may be used with or without the 
grinder means, and with or without the enclosure as exemplified above. When 
the heads are used alone, the "enclosure" then becomes incorporated in the 
individual vacuum heads. 
The intake end 35 of tube 34 may be selectively secured in a sealed 
relationship to the grinder means 27 by an appropriate cam lock coupler 
(not shown) that is commonly available for producing moisture and airtight 
seals between hollow tubes. 
The tube 34 is made up of several interconnected sections 37 having 
sealable fittings 38 at opposed ends. Similar conventional cam lock 
coupler scan be provided for securely sealing these sections together and 
to prevent seepage of air and entrained materials therefrom. 
It is intended that air and moist or dry particulates be drawn or moved in 
a flowing manner along the tube to the van. This is accomplished by air 
movement and may be assisted by jet means 40 along the tube 34. The jet 
means 40 is supplied with a fluidic carrier under a selected pressure 
(approximately 90-3,000 psi) from a pump 41 on the van. The fluid carrier 
is pumped to jet nozzles 42 (FIG. 7) that may be situated at each of the 
sealable fittings 38 along the length of the tube. A common fluid line 
will supply each of the jet nozzles 42. The fluid line may be supplied in 
lengths equal to the tube lengths and attached along the sections to be 
joined as the tube sections are joined togehter. Quick disconnect 
couplings can be provided to interconnect the various water delivery tube 
sections together along the full length of the tube. 
The jet nozzles 42 are shown in FIGS. 6 and 7. They are preferably angled 
in the direction of flow of air and particulates. The fluid discharged by 
the nozzles will contact the transported particles in the moving air 
within the tube. With asbestos, the preferred fluid is water, which serves 
to maintain the particulates in a somewhat wetted condition when required. 
The jets are oriented in the direction of flow to encourage flow of the 
particles along the tube to the van. The jets can further aid in avoiding 
plugging situations that might otherwise develop at the tube joints. 
Fluid may also be supplied from the pump 41 to opposed nozzles 45 situated 
at the top end of the grinder means 27. The fluid here is also utilized to 
further contact the materials received from within the enclosure. Asbestos, 
when dropped into the grinder, will preferably include approximately 15 to 
25% water by volume due to previous wetting. Water jets in the grinder may 
serve to further saturate the received materials and to provide a spray of 
water droplets that will contact and attach a good portion of any 
particulates dislodged by the grinding process. 
In addition to tube 34, two other tubes may be supplied interconnecting the 
van and the enclosure means 15. An auxiliary air tube 46 may be supplied. 
This tube 46 leads from the van to an end connected to the fitting 24 
described above. Tube 46 is used to maintain a low pressure environment 
within the enclosed area by supplementing air flow through the tube 34 or 
substituting for such flow should the tube 34 become clogged or otherwise 
incapable of drawing air from the enclosed area to the van. A make-up or 
return air tube 47 is also supplied between the van and enclosure area 15. 
Tube 47 is used to supply air to the enclosed area. 
The contents of the wheel supported van 13 are shown in somewhat schematic 
form by FIGS. 2 and 3. Basically, the interior of the van body may be 
described as a separator chamber 50 in which collected particulates are 
received and separated from the air stream flowing through the tube 34 and 
auxiliary tube 46 from the removal area. The air is cleaned of particulates 
and is recycled through the make-up air tube 47 or is simply discharged 
into the surrounding atmosphere. Appropriate submicronic air filtration 
(described below) is provided within the separator chamber to adequately 
fitler the received air and render it safe for free discharge to the 
atmosphere. 
A valved tube may extend within the separator chamber, from a sealed 
bulkhead 54 over the collection tank 12. The valved tube is elongated and 
may include three longitudinally spaced discharge spouts that may be 
selectively openable to direct airflow and collected particles into the 
collection tank 12 below. 
A rotatable internal tube 57 may be provided within the valved tube 53. The 
internal tube 57 includes three angularly spaced holes 58. These holes are 
equiangularly spaced at approximately 30.degree. from one another. The 
tube 57 may be connected to a crank 59 extending from the outward tube 53. 
An operator 60 such as a cylinder or motor arrangement may be mounted 
between the crank 59 and van walls. The operator can be selectively 
actuated to rotate the internal tube 57, bringing any selected one of the 
holes 58 into alignment with an associated discharge spout 56. Appropriate 
sensors may be positioned within the tank to detect the level of material 
collecting below each of the tubes. As the collected material reaches a 
prescribed level, the appropriate sensor 62 may be activated. A signal may 
then be sent to the operator which will automatically rotate the internal 
tube to align another of the remaining two holes with its associated 
discharge spout. The discharging material and air will therefore be 
directed through the new opening until the collected material level builds 
to the height of the associated sensor. 
The accumulating material will activate the sensor upon reaching a selected 
height at which time the operator will again be activated to rotate the 
internal pipe for a third time. This will bring the remaining hole into 
position, thereby changing the discharge location for the air and 
entrained asbestos particles. Material build-up will then continue below 
the last discharge opening until the final sensor is activated. The sesor 
may be connected to an appropriate warning device that will indicate the 
tank 12 is full and requires emptying. 
The collection tank 12 is formed within the separator chamber 50 between 
the sealed bulkhead 54 and an upright partition wall 67. An upper edge of 
the wall may be spaced below the ceiling or top of the separator chamber 
to provide a space through which air may flow. The wall 67, along with the 
bulkhead 54 and side walls of the van, form the upwardly open collection 
tank 12 which can be lined with a flexible removable liner 68. The tank 
facilitates removal of collected materials in bulk slurry form through a 
sealable valve such as a gate valve 70. 
Collected particulates will settle by gravity into the collection tank 12. 
The received air will move on through the separator chamber to be cleaned 
and discharged into the atmosphere or returned in a cleaned condition to 
the enclosure means 15 or removal site. The air received from the tubes 34 
and 46 may be moved through a pre-filter arrangement 73 that will collect 
large particulates. It may then be encountered by a series of laminar flow 
baffles 74 which serve to spread the air stream over the entire face 
surface of downstream filter assemblies. 
The airflow may be received from the laminar flow baffles by a filter 
assembly 78. The assembly 78 has the function of removing any remaining 
unsettled particulates and has the further function of drying the air for 
discharge when required. 
The assembly 78 may include a progression of filter elements for this 
purpose. For example, a first wet pre-filter element 81 may use water to 
wash particulates and water droplets containing particulates into a 
receiving tray below. The air may pass through this filter to a secondary, 
dry filter 82. Filter 82 serves to remove more particulates. A second wet 
filter 83 may also be employed adjacent the dry filter 82 to perform a 
further filtering function, along with a second dry filter 84. 
The above filtering arrangement may be repeated as many times as necessary 
to clean the air of large fibers and water droplets before it enters a 
stabilizing air space 85 situated between the last dry filter 84 and a 
final submicronic filter 86. The filters comprising this wall are 
preferably made up of a high efficiency particulate absolute filter 
material capable of filtering approximately 14,000 cubic feet of air per 
minute and removing particulate matter of 0.03 microns and larger. Air 
exiting the high efficiency filter will be sufficiently free of 
particulates to meet or exceed any known safety regulation. 
Airflow and pressure differential is produced within the separator chamber 
50 and through the various tubes to the enclosed area by operation of an 
air displacement means generally shown at 90 within a forward end of the 
ban body. The air displacement means 90 may be comprised of a single fan 
or a battery of four fans 91 powered by a single drive source. In 
practice, a 125 hp. internal combustion engine has been used connected by 
appropriate belting 93 to drive shafts of the four fans 91. Each fan is 
preferably controlled by an independently operable valve arrangememt 94 
(such as a standard Vortex valve). Appropriate controls can be provided to 
activate the valves according to selected pressure requirements and the 
nature of material being removed from the structure. 
A discharge 95 may feed return air from the van to the removal area by the 
return air tube 47. An appropriate connection can be made at discharge 95 
to releasably secure an end of the return air 47. Return or discharge air 
can be controlled by the appropriate control valves 94 or by an internal 
valve (not shown) within the air tube 47 to dictate the amuont of air 
returned to the removal site or the enclosure means 15. Only enough air 
should be returned to the enclosure means 15 through the tube 47 to 
partially make up for the air drawn into the tube 34 and auxiliary tube 
46. The remainder of the make-up air should come from the area immediately 
adjacent to the removal site or the enclosure means 15 to assure any 
potential air leaks will occur in an inward direction and will not allow 
escape of airborne particulates. 
The remaining discharge 96 simply opens to the atmosphere and will allow 
escape of the remaining discharge air that is not recycled back to the 
removal site through tube 47. 
Appropriate controls can be utilized for maintaining low pressure within 
the enclosure means 15 and separator chamber 50. Appropriate sensors 98, 
99, for example, may be situated within the chamber and enclosure 
respectively to constantly monitor the pressure in both areas. An abrupt 
change in pressure differential between the two areas will indicate a 
difficulty. 
For example, a sudden drop in pressure within the separator chamber may 
indicate a stoppage along the tube 34. Action can then be taken responsibe 
to the pressure differential to alleviate the problem. The fan control 
valves 94 may then be opened to enlist the help of additional air flow to 
further lower the pressure within the separator chamber, producing a 
suction that will normally pull any blockage through the tube 34 and into 
the collection tank. The added air flow 91 will also serve to maintain the 
low pressure area within the enclosure means 25 through the auxiliary air 
tube 46. Valving within the make-up or replacement air tube 47 can also be 
used in appropriate situations to decrease the amount of air returning to 
the enclosed area, thereby further assuring that the low pressure area 
will be maintained while the blockage is being removed. 
Various other forms of sensors and controls may be supplied that are well 
within the capabilities of control system designers. 
The present process may be best understood in conjunction with an 
explanation of the operation for the present system. Firstly, however, it 
should be understood that the entire system may be enclosed within the 
portable van. All the tubes and the enclosure structure 15 can be carried 
within a storage space 105 at the rear of the van, behind the bulkhead 54. 
Doors (not shown) can be sealed at this area and secured for transport of 
the entire system to a work site. 
In the example for asbestos removal, the van is first positioned at an area 
adjacent to the structure where the storage space 105 can be opened and the 
tubes and exclosure means can be removed and assembled. An area can then be 
enclosed about the site where asbestos is to be removed simply by 
positioning the enclosure means 15 such that the open end 17 is situated 
about the area against an appropriate surface. If another form of the 
enclosure means is to be utilized, the process remains similar. The 
enclosure may also become an actual room within the structure and the 
enclosure means 15 may simply be a sealing device for securing the tubes 
to a doorway or window. 
After the area has been properly enclosed, and the tubes 34 assembled and 
connected to the separator chamber, the fans can be driven to produce a 
pressure differential within the enclosed area. This pressure differential 
is created about the asbestos to be removed so that air pressure within the 
enclosed area is lower than that of the surrounding ambient pressure. Any 
seepage will be directed into rather than out of the enclosed area. Any 
flying particulates or fibers will therefore be maintained within the 
enclosed area and there will be no danger of fibers escaping the enclosure 
even though a small "leak" may exist. 
When the pressure differential has been established, action can be 
initiated for removal of the asbestos. This can be accomplished by a 
worker within the assembled enclosure 15. It is advisable first to wet the 
asbestos with water and a saturant material such as polyethylene glycol. 
Enough water is applied to the asbestos to saturate the material to a 
water content of between 15 and 25%. This reduces the amount of flyable 
particulates that will be freed when the asbestos is removed from the 
adjacent structure. 
The next step after wetting the asbestos is to remove it from the 
structure. This can be done using standard and/or power tools since the 
area is secured by the enclosure means 15. The removed asbestos is then 
placed through the funnel where it is drawn through the tube 34 in an air 
stream to the collection tank 12 within the van. The same air movement 
that is used to produce the pressure differential is also used to move the 
wetted asbestos material along the tube and into the separator chamber 50. 
The asbestos particles arriving at the separator chamber 50 are allowed to 
drop into the storage tank 12 from the incoming air. The air is then 
filtered within the chamber 50 to remove asbestos particles and the 
cleaned air is subsequently exhausted. Exhausted air may be returned to 
the atomsphere or a portion of the air can be returned to the enclosed 
area by the return air tube 47. 
The above process may be augmented by grinding the asbestos received 
through the enclosure just as it enters the tube. The ground or comminuted 
asbestos particles will move freely along the length of the tube when 
ground into fine particulates. 
Flow along the tube may be encouraged by injecting water under relatively 
high pressure (approximately 90 psi or higher) at stations along the 
length of the tube. This is accomplished by the water jet means 40 as 
described above. The jets serve to increase the flow of asbestos particles 
along the tube to the separator chamber and to wet the flying asbestos 
particles as they move along. This facilitates movement through the tube 
and encourages separation by gravity as the air and entrained droplets 
with attached particulates enter the chamber over the collection tank 12. 
The heavy water droplets and solid asbestos particulates will drop into 
the collecting tank 12. 
The process may also be enhanced by producing an auxiliary airflow from the 
enclosed area to the separator chamber 50. The auxiliary tube 46 can be 
used to draw air from the enclosed area to the storage tank, supplementing 
the air movement through the tube 34. 
The process continues by filtering air within the separator chamber to 
clear the air by removing flyable asbestos particles. This step may be 
accomplished by passing the air received within the chamber through the 
filter assemblies described above. 
Asbestos can be continually removed within the enclosed area until all 
traces are drawn through the tube 34 and received within the sealed 
separator chamber 50. 
The entire area can be washed down with water before the system is shut 
down to facilitate movement of the enclosure to another area. Relocation 
of the enclosure within the same structure can be accomplished simply by 
moving the support 22 and subsequently reattaching the enclosure means to 
the structure about a new source of asbestos to be removed. The above 
process is then repeated until all the harmful material has been removed 
from the structure. 
When all asbestos has been removed the enclosure means can simply be 
appropriately folded and the tubes disconnected and gathered into the 
truck where it can be stored and transported to the next site. 
The present process will leave the structure clean and free of harmful 
asbestos particles while the operation remains safe to the workers 
accomplishing the asbestos removal. It is stimated the cost and completion 
time will be significantly reduced using the present system and process in 
comparison to the existing systems in current use. 
Asbestos materials is used as an example but the system and process can be 
used on any number of hazardous, toxic or nuisance materials by adjusting 
the airflow rate and filter media. For example, for use in removing PCB's 
(polychlorinated biphenol), activated charcoal filters may be used along 
with the submicronic high efficiency particulate absolute filter. Also, in 
PCB removal, the jet means would be utilized to deliver a fluid other than 
water to assist motion of the material along the tube, and a removable 
stainless steel collector tank would preferably be used in place of the 
flexible liner 68. 
In compliance with the statute, the invention has been described in 
language more or less specific as the structural features. It is to be 
undertood, however, that the invention is not limited to the specific 
features shown, since the means and construction herein disclosed comprise 
a preferred form of putting the invention into effect. The invention is, 
therefore, claimed in any of its forms or modifications within the proper 
scope of the appended claims, appropriately interpreted in accordance with 
the doctrine of equivalents.