AU2020100156A4 - Containment Unit - Google Patents

Abstract

Disclosed herein is a containment unit for managing inhalable waste products, the containment unit having an enclosure and a filtration unit external to the enclosure connected thereto via a duct, the filtration unit having means for directing the air from the enclosure via a duct from an input at one side of a housing to an output at the opposite side of the housing and having a pair of filters therebetween before expelling the filtered air external to the enclosure via the output, wherein the pair of filters includes a secondary filter for removing fine inhalable waste products and a primary filter precedes the secondary filter and removes larger inhalable waste products for preventing clogging of the secondary filter. In a preferred embodiment, the secondary filter is a HEPA filter and the primary filter is a pre-filter. 2%0 22/Z3 u1 2 Fig. 1

Description

CONTAINMENT UNIT

FIELD OF THE INVENTION [0001] This invention relates to a containment unit for managing inhalable waste products commonly produced by the construction industry.

BACKGROUND [0002] Construction sites produce large amounts of waste products in the form of dust and other airborne contaminants such as silica, MDF, stone, wood or concrete particles. The contaminants, being airborne, can spread throughout the worksite and beyond. These contaminants may be harmful to the people inhaling them, and these may be construction workers or other personnel near or on the construction site, such as residents living nearby or office workers.

[0003] In recent history there has been an epidemic of chronic and long term illness that have been attributed to inhaled waste products as a result of the construction industry. In particular, the inhalation of silica dust can cause silicosis, which is a debilitating and sometimes fatal lung disease. Previous to that asbestosis was a disease from the inhalation of asbestos and this is still a current problem when renovating old buildings.

[0004] In Australia, the number of workers potentially affected by inhaled wasted products such as silica dust is estimated to be about 2.3 million. This silica dust is produced by blasting, grinding, cutting, polishing, drilling or breaking materials, such as granite, sandstone, slate, metallic ores or concrete. For example, grinding and polishing granite kitchen countertops or cutting concrete may produce silica dust. The silica dust can be very fine, and cause inflammation and scarring when inhaled into the lungs. Also the silica exposure is suspected to increase the risk of tuberculosis, bronchitis, pulmonary disease and other health problems like renal failure and autoimmune diseases. As chronic silicosis develops slowly, it may take years for signs and symptoms to appear. Furthermore as treatments are unable to reverse the disease, prevention of the disease is key.

[0005] Wet sprays and wet cutting methods have been employed to reduce dust exposure during the process of construction. Increasing ventilation and use of suitable masks for workers called ‘respirators’ can also be used to prevent inhalation of waste construction products. Monitoring air quality and/or monitoring workers for early identification of disease. However

2020100156 30 Jan 2020 these methods do not effectively remove all the waste products from the site so workers can be affected by the dust at the end of the day and other personnel may also be affected such as nearby personnel or residents who are not subject to these prevention measures. Other methods include the constructions of temporary walls to contain the dust which consist of taped plastic sheets onto telescopic poles however adequate sealing of the temporary walls is not achievable due to inevitable holes in the plastic or gaps around pipes etc. Inadequate ventilation within the temporary walls often choke the workers within or discourage them from using it.

[0006] The applicant, through their experience on worksites for 50 years and in-depth research, has observed that no adequate system or service has been introduced in Australia to manage inhalable waste products adequately on sites.

[0007] Examples of the invention seek to solve or at least ameliorate one or more disadvantages of prior methods to prevent workers from inhaling airborne waste products from construction sites and risk of damage to lung health.

[0008] The above references to and descriptions of prior proposals or products are not intended to be, and are not to be construed as, statements or admissions of common general knowledge in the art. In particular, the above prior art discussion does not relate to what is commonly or well known by the person skilled in the art, but assists in the understanding of the inventive step of the present invention of which the identification of pertinent prior art proposals is but one part.

SUMMARY OF THE INVENTION [0009] According to the present invention there is provided a containment unit for managing inhalable waste products, the containment unit having an enclosure and a filtration unit external to the enclosure connected thereto via a duct, the filtration unit having means for directing the air from the enclosure via a duct from an input at one side of a housing to an output at the opposite side of the housing and having a pair of filters therebetween before expelling the filtered air external to the enclosure via the output, wherein the pair of filters includes a secondary filter for removing fine inhalable waste products and a primary filter precedes the secondary filter and removes larger inhalable waste products for preventing clogging of the secondary filter. In a preferred embodiment, the secondary filter is a HEPA filter and the primary filter is a pre-filter.

2020100156 30 Jan 2020 [0010] The air can be directed generally upwardly through the enclosure and through an input of the duct at an upper portion of the enclosure before being directed into the filtration unit. Preferably, the air enters the enclosure at a bottom portion or beneath walls of the enclosure.

[0011] The enclosure may comprise a collapsible framework onto which flexible fabric in the form of wall panels and a ceiling panel is attachable and sealable together to form a room for performing construction tasks which produce inhalable waste products. Preferably, bottom edges of the wall panels are supported above a worksite ground surface thereby forming a gap through which air can be drawn and is directed upwardly towards the ceiling. The framework can have extendable legs for supporting the wall panels.

[0012] At least part of the input side of the filtration unit can be removable for allowing replacement and/or maintenance of the primary filter. Preferably, the primary filter is a filter having a thickness greater than 50mm. More preferably, the primary filter is a pleated filter. The secondary filter can be a HEPA filter or other filter for filtering ultra-fine particles.

[0013] In a preferred embodiment, the filtration unit includes a sensor to monitor the filtering ability of the filtration unit. Preferably, the containment unit also includes a motor to power the means for directing air from the enclosure. Preferably, the means for directing air from the enclosure is an centrifugal fan.

[0014] The ceiling panel may be substantially flat when the enclosure is in an erected configuration.

[0015] The containment unit can include a filter at the input of the duct for filtering dust particles. Preferably, the containment unit can include a ventilation member having an intake port being open to the enclosure and an output connected to the input of the duct and wherein the filter is housed therebetween for filtering the air drawn from the enclosure into the duct.

[0016] The side edges of each wall panel can be attachable to another such wall panel, and where the top edge of each wall panel is attachable to the ceiling panel. Preferably, the panels are attachable by hook and loop fasteners (known commonly as Velcro fasteners) or zip fasteners.

[0017] In a particularly preferred embodiment, the airflow through the containment unit is at least 2000 CFM and wherein the cross-section area through which the air is drawn is at least 900 mm .

2020100156 30 Jan 2020

BRIEF DESCRIPTION OF THE DRAWINGS [0018] The present invention will now be described, by way of non-limiting example, with reference to the accompanying drawings in which:

[0019] Fig. 1 is a cross-section view of a containment unit for managing inhalable waste products according to a first preferred embodiment of the invention;

[0020] Fig. 2 is a perspective view of the containment unit according to another preferred embodiment of the invention in-situ;

[0021] Fig. 3 is a close-up internal view of the containment unit of Fig. 2;

[0022] Fig. 4 is a cross-section view of a filtration unit; and [0023] Fig. 5 is a perspective view of the containment unit.

DETAILED DESCRIPTION OF THE INVENTION [0024] Preferred features of the present invention will now be described with particular reference to the accompanying drawings. However, it is to be understood that the features illustrated in and described with reference to the drawings are not to be construed as limiting on the scope of the invention.

[0025] Referring now to Figs. 1 to 5, there is shown a containment unit 2 for managing airborne particles produced by construction work according to preferred embodiments of the present invention. The containment unit 2 comprises an enclosure 4 which allows sufficient space for at least one user 6 to perform a task such as blasting, grinding, cutting, polishing, drilling or breaking materials such as granite, sandstone, slate, metallic ores or concrete, which produces harmful airborne inhalable waste products such as dust into the air. The containment unit 2 also comprises a filtration unit 8 for removing the waste products from the air which intakes air from the enclosure 4 and directs it into the filtration unit 8 for removal of the inhalable waste products and then emits the filtered air external to the enclosure 4. A duct 10 connects the enclosure 4 and the filtration unit 8 such that contaminated air is drawn from the enclosure 4 into the filtration unit 8 to filter the air before it is expelled into the external environment.

[0026] The containment unit 2 therefore advantageously isolates the harmful inhalable waste products produced from the external environment so that they do not harm the workers external to

2020100156 30 Jan 2020 the enclosure, and furthermore removes the waste products safely so that they reduce the airborne contamination on the worksite. This reduces the risk that the inhalable waste products can have on a worker’s health and safety during the construction work.

[0027] The enclosure 4, as shown in Figs. 1 and 2, has a ceiling panel 12 and four wall panels 14 which are attachable to a frame structure 16, and further the wall panels 14 attach to the four sides of the ceiling panel 12 by fasteners such as hook and loop fasteners. Preferably, four wall panels 14 forms the sides of the enclosure 4 such that it forms a usable cubic work area 15. The wall panels 14 are attachable at the side edges by fasteners such as a zipper, preferably a heavy duty zipper to form corners of the enclosure 4. Having zip fasteners along the side edges of each wall panel 14 allows the wall panels to be interchangeable to form different sized enclosures 4 to suit differing work place conditions. The wall panels 14 and ceiling panel 12 are preferably made of a fire-resistant fabric material, such as a PVC-coated polyester fabric material.

[0028] The wall panels 14 are configured so as to have openings for access into the enclosure, such as a door 18 or utility access opening 20 such as for allowing passage of cabling or ducting. The door 18 may have zip or hook and loop fasteners for closures and ease of use. The utility access openings 20 have flaps which are adapted to seal the openings 20 when not in use by use of fasteners such as hook and loop fasteners.

[0029] The frame structure 16 preferably has a foldable arrangement, for example trusses 17, which allows for rapid deployment and dismantling, and packs quickly into a portable configuration which allows for easy transportation and storage. Most preferably, the portable configuration of the enclosure 4 is 60 times less than its size when erected which allows manoeuvrability around crowded and/or tight worksites with minimal access. The frame structure 16 comprises a lightweight metal material such as high-grade aluminium tubing with internal webbing reinforcement which has the advantage of being lightweight, durable and strong enough to withstand construction site and trade conditions. The frame structure 16 advantageously allows the erection of the enclosure 4 without any internal support posts which could obstruct the work area 15.

[0030] The preferred sizes for these enclosures 4 are about 3m by 3m or 3m by 4.5m which allows one worker to work comfortably in this work area 15 however it can be understood that the arrangement of the enclosure 4 could be adapted to be of any size as required. The enclosure 4 can also include other safety features such as a log book pouch which records filter replacement history and inspection reports or safety signs on the wall panels 14.

2020100156 30 Jan 2020 [0031] The internal ceiling panel surface is preferably parallel to the floor and perpendicular to the wall panels 14. The containment unit 2 includes an air ventilation member under the ceiling panel 12 and above the work area 15 which is connected to the duct 10. The air ventilation member can be in the form of a ventilation box 22 as illustrated in Fig. 1 having a grill at an intake port 23 which is open downwardly towards the work area 15.

[0032] The air ventilation box 22 which is preferably directly centrally above the work area 15 to draw air and dust from the enclosure 4 into the duct 10, through the enclosure wall via the duct access opening 20 and into the filtration unit 8. The legs 21 of the frame structure 16 are extendable so as to raise the bottom edge of the wall panels 14 above the surface of the work area 15 so as to form a gap that allows the passageway of external air at the bottom outer edges of the enclosure such that a positive pressure to be formed and fresh air is drawn through the gap 24 at the bottom of the enclosure 4 to the ventilation box 22 at the upper portion of the enclosure 4.

[0033] Preferably, the bottom edges of the wall panels 14 are raised about 50mm above the ground surface however this can be varied as required to suit conditions. The gap 24 also prevents the wall panels 24 from collapsing inwardly from the positive air pressure. The applicant has found that the arrangement of the gap 24 under the wall panels 14 and the substantially centrally located air ventilation box 22 creates an even upwardly airflow about the work area 15 which is most effectively at drawing the airborne work products into the air ventilation box 22 and consequently the filtration unit 8. The applicant has also found that if the air ventilation box 22 is not centrally located then the air is directed from the closest gap 24 and creates an uneven flow of air.

[0034] The air ventilation box 22 also includes a filter for removing large particles of inhalable work products. Preferably the filter for removing large particles is a material filter 26 as illustrated in Fig. 1. The air ventilation box 22 is arranged to allow easy access to the material filter 26 for maintenance or replacement, for example the air ventilation box 22 has a slidable frame 28 which fits over the intake port 23 which can hold the material filter 26.

[0035] Advantageously, a flat ceiling substantially planar with the air intake port 23 prevents any dust from accumulating above the air intake port 23 and also by having less volume above the air intake port 23 it is also easier to create a positive airflow. In comparison, in a pitched roof common to many tent-like enclosures, dust rises and accumulates in above the air ventilation box 22 and the additional volume increases the difficulty of producing a positive air pressure and even air flow. Furthermore a flat ceiling allows the enclosure 4 to fit more easily into worksites having low ceiling heights.

2020100156 30 Jan 2020 [0036] The enclosure 4 can also include at least one illumination means in the ceiling for illuminating the work area. Preferably, the illumination means are bright LED lights 30 which are powered by the filtration unit 8 via power cables which can enter the enclosure 4 via utility access openings 20 as discussed in the above paragraphs.

[0037] The air intake port 23 which has a large surface area which allows the passageway of a large volume of air. Preferably the air ventilation box is connected to a duct is formed and which directs air from the air vent to the filtration unit which is located preferably external to the enclosure. The duct passes through the enclosure wall via an opening which has a flap which can seal about the opening when it is not in use. The duct is preferably of a flexible collapsible fireresistant material such aluminium laminate.

[0038] The applicant has also found that a single cut of concrete can cause airborne particles which can take 15-20 minutes to settle. Thus the upwardly directed and even air flow advantageously assists in both lifting low-lying dust from or about the work area floor and also draws the rising and suspended dust effectively upward and into ventilation box 22, the duct 10 and the filtration unit 8 away from the user 7.

[0039] The filtration unit 8 has a housing 32 which is supported from the ground by rollers, such as swivel castors 34, and where the air flow is directed from an end of the duct 10 connected to an inlet 36 at one side of the housing 32 to an outlet 38 at the opposite side of the housing 32 where the filtered air is expelled. The swivel castors 34 can have a large diameter, for example 15 cm diameter, and formed of rubber material for ease of manoeuvrability and portability over uneven surfaces in a construction site.

[0040] Preferably, the housing inlet 36 is a spigot and the outlet 38 has a half-chevron grill for directing the air away from the ground to avoid kicking up dust. Between the inlet 36 and outlet 38 the filtration unit 8 has a first or secondary filter 42, a second or primary filter 40 and a centrifugal fan 44 for drawing the air from the enclosure 4, via the air ventilation box 22 and duct 10, and through the filters 40, 42. The filtration unit 8 also includes a motor 46 for powering the fan 44 and power points 48. The power points 48 can power any electrical items, such as the LED lights 30 or power tools used in the enclosure 4.

[0041] The filtration unit 8 is also configured to be used internal to the enclosure 4 if required in small workspaces. In this case, the spigot at the inlet 36 and grill at the outlet 38 of the filtration

2020100156 30 Jan 2020 unit 8 is exchanged and the inlet of the duct 10 is connected to the outlet 38 so that air is drawn from within the enclosure 4 before being filtered and expelled externally via the duct 10.

[0042] As illustrated in Fig. 4, the second filter 40 is a filter that can remove the ultra-fine dust particles or construction waste products, and thereby filter the air to be sufficiently clean for safe inhalation and therefore can be expelled from the filtration unit 8 at the outlet 38. Preferably, the second filter 40 is a HEPA filter or other high-grade filter which removes ultra-fine particles and dust. The first filter 42 is a pre-filter to the second filter 40 which is configured to remove the larger particles so as to prevent these larger particles from clogging the second filter 40. The portion 50 of the housing 32 adjacent the first filter 42 is configured to be removable so as to allow maintenance and/or replacement of the first filter 42. The first filter 42 is preferably a pleated prefilter which increases the surface area for more effective filtration. Even more preferably the first filter 42 has a thickness of at least 50mm to handle the required air flow and most preferably has a thickness of at least 100mm. Previously used pre-filters have a thickness of 10mm which is not sufficient to handle the required airflow.

[0043] The filtration unit 8 is arranged to hold the filters sealably such that substantially all the dust is forced to pass through the filters 40, 42 and therefore ensures that all harmful particles are removed from the air before being expelled into the external environment. Preferably, the filtration unit 8 has sealing material to hold the filters within the filtration unit such as silicon or rubbers seals.

[0044] The filtration unit 8 includes a sensor which monitors the air pressure and the sensor output can be viewed as a gauge 52 on the filtration unit to allow constant monitoring. In a preferred embodiment, the gauge is a magnahelic gauge 52. As the filters 40, 42 accumulate dust and other particles the pressure rises indicating that maintenance such as cleaning or replacement of filters may be required. It is proposed that weekly inspections of the filtration unit 8 and containment unit 2 in general is performed to ensure that the unit 2 operates effectively and efficiently with the prescribed air flow and filtration specifications.

[0045] To ensure that the airborne dust is removed from the enclosure the applicant has found that there must be sufficient positive pressure and air flow directed upwardly through the enclosure 4 and into the duct and filtration unit such that the air expelled from the filtration unit 8 is clean. Further the air flow must be sufficient to filter the air through the filters 40, 42, particularly if the second filter is a HEPA filter. To achieve this, the fan must be powerful enough to direct the air and therefore it is preferable that the fan is a powerful centrifugal impeller, commonly used for

2020100156 30 Jan 2020 commercial operations, which is driven by a 240V motor, and which is configured to operate all year round.

[0046] As the filtration unit 8 of the example as described above is of substantial weight and size, the applicant has found it is necessary to house it in a portable unit separable from the enclosure 4 as it is not possible to house the filtration unit 8 in the ceiling of the enclosure 4 which would also compromise the strength of the framework of the enclosure 4. In addition, having the filtration unit 8 external to the enclosure and at ground level allows for convenient and easy replacement and maintenance of the filters 40, 42 and filtration unit 8 in general.

[0047] To have sufficient air flow, for example 2000 CFM, thereby optimising the airborne dust filtration, the applicant has found that air resistance reduction is also important and this is preferably achieved by having a large cross-sectional area, for example, about 900mm², through which the air is directed from the enclosure 4 to the output of the filtration unit 8. In the illustrated example of Figs. 1 to 5, the duct 10 has a diameter of 300 mm, the intake port of the ventilation box 22 has an area of 600 mm x 900 mm, the inlet 36 has a diameter of 300 mm, the first and second filters 40, 42 have area of about 600 mm x 600 mm respectively. This is a mere example and it would be understood by a person skilled in the art that the cross-section areas of the duct 10, filtration unit 8 and ventilation box 22 can be varied as required.

[0048] Through-out the specification and claims the word “comprise” and its derivatives is intended to have an inclusive rather than exclusive meaning unless the context requires otherwise.

[0049] Orientational terms used in the specification and claims such as vertical, horizontal, top, bottom, upper and lower are to be interpreted as relational and are based on the premise that the component, item, article, apparatus, device or instrument will usually be considered in a particular orientation, typically with the assembly uppermost.

[0050] It will be appreciated by those skilled in the art that many modifications and variations may be made to the methods of the invention described herein without departing from the spirit and scope of the invention.

Claims (19)

1. THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

   1. A containment unit for managing inhalable waste products, the containment unit having an enclosure and a filtration unit external to the enclosure connected thereto via a duct, the filtration unit having means for directing the air from the enclosure via a duct from an input at one side of a housing to an output at the opposite side of the housing and having a pair of filters therebetween before expelling the filtered air external to the enclosure via the output, wherein the pair of filters includes a secondary filter for removing fine inhalable waste products and a primary filter precedes the first and removes larger inhalable waste products for preventing clogging of the secondary filter.
2. 2. A containment unit according to claim 1, wherein the air is directed generally upwardly through the enclosure and through an input of the duct at an upper portion of the enclosure before being directed into the filtration unit.
3. 3. A containment unit according to claim 2, wherein the air enters the enclosure at a bottom portion or beneath walls of the enclosure.
4. 4. A containment unit according to any one of the preceding claims, wherein the enclosure comprises a collapsible framework onto which flexible fabric in the form of wall panels and a ceiling panel is attachable and sealable together to form a room for performing construction tasks which produce inhalable waste products.
5. 5. A containment unit according to claim 4, wherein bottom edges of the wall panels are supported above a worksite ground surface thereby forming a gap through which air is drawable and directed upwardly towards the ceiling.
6. 6. A containment unit according to claim 5, wherein the framework has extendable legs for supporting the wall panels.
7. 7. A containment unit according to any one of the preceding claims, wherein at least part of the input side of the filtration unit is removable for allowing replacement and/or maintenance of the primary filter.
8. 8. A containment unit according to claim 7, wherein the primary filter is a filter having a thickness greater than 50mm.

   2020100156 30 Jan 2020
9. 9. A containment unit according to claim 7 or claim 8, wherein the primary filter is a pleated filter.
10. 10. A containment unit according to any one of claims 7 to 9, wherein the secondary filter is a HEPA filter or equivalent.
11. 11. A containment unit according to any one of the preceding claims, wherein the filtration unit includes a sensor to monitor the filtering ability of the filtration unit.
12. 12. A containment unit according to any one of the preceding claims, including a motor to power the means for directing air from the enclosure.
13. 13. A containment unit according to any one of the preceding claims, wherein the means for directing air from the enclosure is an centrifugal fan.
14. 14. A containment unit according to claim 4, wherein the ceiling panel is substantially flat when the enclosure is in an erected configuration.
15. 15. A containment unit according to claim 2, including a further filter at the input of the duct for filtering dust particles.
16. 16. A containment unit according to claim 15, having a ventilation member having an intake port being open to the enclosure and an output connected to the input of the duct and wherein the further filter is housed therebetween for filtering the air drawn from the enclosure into the duct.
17. 17. A containment unit according to claim 5 or claim 6, wherein the side edges of each wall panel is attachable to another such wall panel, and the top edge of each wall panel is attachable to the ceiling panel.
18. 18. A containment unit according to claim 17, wherein the panels are attachable by hook and loop fasteners or zip fasteners.
19. 19. A containment unit according to any one of the preceding claims, wherein the airflow through the containment unit being at least 2000 CFM and wherein the cross-section area through which the air is drawn is at least 900 mm².