DESC:FIELD OF INVENTION

The present invention relates to an arrangement for providing a safe working environment to the person working within a confined space. In particular, the present invention relates to an arrangement for providing a safe and quick exit to the person working inside a confined space in case of emergency situations. More particularly, the present invention relates to an arrangement for safely cleaning water tanks of air supply units (ASUs) of spray painting booth in automotive paint shops

BACKGROUND OF THE INVENTION

In any paint shop, the Air Supply Unit (ASU) supplies conditioned air to the different spray painting booths. This conditioned air to be supplied to the spray booths should conform to various parameters such as temperature between 24 to 260C and relative humidity (RH) between 65 to 75%.

Thus, in order to maintain the relative humidity in ambient air, the Air Supply Units (ASUs) include water spray chambers consisting of water tank for washing out air with the help of water raiser pipes provided with nozzles and actuated by the pumping system.

On washing out this ambient air in the chamber, the muck (e.g. dust, dirt present in the ambient air) is collected at the bottom of the tank, which needs to be cleaned on every weekly off to avoid the contamination of the air quality supplied to the spray booths with such impurities.

While performing such cleaning activities of the water tank provided for the water spray chamber, a dedicated cleaning associate is required to be sent inside the water spray chamber through a small marine door of dimension 3 feet x 2 feet. Since only one small sized door is available here, in case of any emergency situation, this cleaning associate can escape from the confined space of this water spray chamber only with difficulty.

Therefore, this water spray chamber falls under the definition of the “Confined space” requiring compliance with all legal regulations associated therewith. This requires additional expenditure and formalities of such legal compliance.

PRIOR ART

“Prevention through Design: Eliminating Confined Spaces and Minimizing Hazards” provides top design principles developed by the American Industrial Hygiene Association (AIHA) and approved by AIHA Board of Directors in May 2014. It indicates the main design principles to be considered while encountering confined spaces. It involves preventing the creation of confined spaces or eliminating the existing confined spaces.

US 5765544 A discloses a humidifier for use with counter- or down-flow furnaces such as those traditionally found in mobile homes. The humidifier includes a louvered tip-out access door, behind which a drawer containing a water panel is housed. The drawer is detachably snap-fitted to the inside of the access door. Water is directed onto the water panel by a water dispersion bar, which is snap-fitted into the top of the drawer above the water panel. As air is drawn through the humidifier installed over the return air louvers of a counter-flow furnace, tiny water droplets in the water panel are picked up by the moving air stream and carried into the home. The tip-out feature of the access door and the snap-fit connections allow for simple, easy repair and cleaning, even by an untrained person, thus avoiding the need for a skilled technician when only routine maintenance is necessary.

US 20110239670 A1 discloses a method for managing access to a confined space cooled by direct injection of a cryogenic fluid, which comprises at least one closure system for closing the confined space to prevent access to the confined space and which can be opened/closed to a variable and controllable degree, and including a data acquisition and processing device. The device controls the open or closed state of the closure system; sets and controls the degree to which the closure system is opened/closed; ensures that a time delay (TP) is respected every time the closure system is closed, after this time delay, injecting cryogenic fluid into the space resumes; and implements the cycle for opening the closure system at the request of a user. The device determines the time elapsed (TE) in the closed position since the last closure cycle of the closure system and compares TE to TP. If TE=TP the device immediately authorizes the opening of the closure system. If TE>TP the device authorizes the opening of the closure system after a predefined waiting time.

DISADVANTAGES WITH THE PRIOR ART

The main problem associated with conventional cleaning of the water tank of water spray chambers in paint shops, e.g. in automotive paint shops is the safe and quick exit from the confined spaces in case of any emergency situations.

Normally, this water spray chamber includes a water tank (for example, of an area of 8 m X 1.25 m X 0.6 m), which has only one opening for entry into and exit therefrom. Therefore, it falls under the definition of “Confined space” and requires complying with all legal regulations associated therewith. Accordingly, additional manpower should be provided as a trained First Aid personnel as well as a full-time contract supervisor for observing the entire cleaning activity.

Since only one small window is available, it is a confined space, which could be unsafe in case of emergency situations and therefore attracts legal provisions applicable to such confined spaces.

Moreover, the mandatory Confined work permit should be filled every week along with signature of the concerned authorities on site after checking the compliance with all legal requirements to avoid any probable unsafe conditions for the manpower engaged in such cleaning activity.

OBJECTS OF THE INVENTION

Some of the objects of the present invention - satisfied by at least one embodiment of the present invention - are as follows:
An object of the present invention is to provide an arrangement for facilitating a safe and quick exit to the person working inside a confined space, in case of emergency situations.

Another object of the present invention is to provide an additional exit from the humidity chamber of the air supply unit of spray booth in a paint shop.

Still another object of the present invention is to eliminate confined space within humidity chamber of the air supply unit of spray booth in paint shop.

Yet another object of the present invention is to provide an arrangement, which obviates compliance of legal provisions applicable to confined spaces.

A further object of the present invention is to provide an arrangement, which does not affect the air Flow and prevents water leakages from the humidity chamber of the air supply unit of spray booth in a paint shop.

These and other objects and advantages of the present invention will become more apparent from the following description, when read with the accompanying figures of drawing, which are however not intended to limit the scope of the present invention in any way.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided an arrangement for safely cleaning the water tank of air supply unit (ASU) of spray painting booth in an automotive paint shop, the arrangement comprising a plurality of subsections including burner section, pre-filter section, eliminator plate gallery having eliminator plate bank, humidifier section, fan room, sound damper section, post-filter section, and delivery zone; characterized in that a separate leak-proof door is configured with a profile similar to the eliminator plates of the eliminator plate bank, the door adapted to be opened to perform the cleaning activity of the water tank and to be closed after completion of the cleaning activity for eliminating any disturbance in air flow over the door.
Typically, the door is provided in the humidifier subsection and facing the pre-filter section.

Typically, the door opens inside the pre-filter section for an automatic closure thereof during the cleaning activity due to the air-flow entering the burner section through a door provided therein and subsequently hitting the door on entering the pre-filter section.

Typically, the separate leak-proof door comprises a plurality of hinges on one side length thereof, at least a pair of locking arrangement with respective wing nuts, and a door handle fitted therebetween for opening and closing thereof.

Typically, the separate leak-proof door is fitted on the existing eliminator plate bank by modifying only the LNG supply pipe, filter section area, platform on the water tank with railing and eliminator plate fitment thereof.

Typically, the burner section maintains the required temperature, preferably at 24-260C by heating ambient air, more preferably by using LNG gas entering through the door provided therein.

Typically, the pre-filter section comprises coarse media bag filters for arresting the dirt and dust particles present in air supplied to the air supply unit (ASU).

Typically, the eliminator plate gallery is configured of eliminator plates arranged in a 3-pass system, the gallery forming a respective wall on either side of the humidifier section for eliminating water droplets in air flowing therethrough.

Typically, the separate leak-proof door is made of 50 mm steel box section, preferably of 790 mm x 1870 mm.

Typically, the water tank of air supply unit (ASU) of spray painting booth comprises an air-entry door and the separate leak-proof door to avoid creation of any confined space therein due to easy access and exit from the water tank for the personnel performing the cleaning activity, and thereby does not require any legal compliance.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will be briefly described with reference to the accompanying drawings.

Figure 1a shows a line diagram of the top view of a conventional Air Supply Unit (ASU) 100 in an automotive paint shop.

Figure 1b shows a schematic diagram of the humidifier chamber section.

Figure 1c shows a schematic diagram of conventional eliminator plate bank.

Figure 2a shows an actual existing eliminator plate bank inside the humidity chamber of the air supply unit of spray booth in a paint shop.

Figure 2b shows a schematic diagram of the eliminator plate section configured in accordance with the present invention, provided with a separate door therein.

Figure 2c shows single door provided in the eliminator plate bank of Fig. 2b.

Figure 2d shows a door frame for fixing a separate door of Fig. 2c in the eliminator plate bank.

Figure 2e shows a schematic diagram of the humidifier chamber section equipped with an additional separate door configured in accordance with the present invention.

Figure 3 shows a graphical representation of the number of permits per year granted for cleaning of the confined spaces in ASUs.

DETALED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

In the following, the eliminator plate section configured with a single separate door in accordance with the present invention will be described in more details with reference to the accompanying drawings without limiting the scope and ambit of the present invention in any way.

Figure 1a shows a line diagram of the top view of a conventional Air Supply Unit (ASU) 100 in an automotive paint shop. It includes a burner section 10 to maintain the required temperature at 24-260C by heating ambient air by using LNG gas. The ambient air enters into the burner section 10 through a small marine door provided by the OEM for entry of personnel inside the dehumidifier tank. A pre-filter section 20 consisting of coarse media bag filters for arresting the dirt and dust particles present in air supplied to the ASU 100, an eliminator plate gallery 30 configured in 3-pass system and made as a respective wall on either side of the humidifier section 40 for eliminating water droplets present in the air flowing therethrough. The humidifier section 40 containing water supply header with piping or raisers fitted with nozzles for spraying fine particles of water being pumped by the pumping system located outside ASU 100. A water tank is also provided at the bottom of this water supply header for collecting and recirculating water. This humidifier section 40 washes out air to settle dirt and dust particles (muck) at the bottom of the water tank and maintains 65-75% relative humidity of the air flowing into the spray booth. ASU 100 further includes a fan room 50 for accommodating fans driven by 132 kW motors to circulate air into the next section by a forced air-circulation, e.g. at a rate of 163800 m3/hr. ASU 100 also includes a sound damper section 60 for dampening the air noise by means of acoustic material embedded in the MS structure thereof and for equal distribution of air flowing into the next section. ASU 100 additionally includes post-filter section 70 consisting of fine media bag filters for arresting dirt and dust particles present in the air flowing out of the sound damper section 60. Finally, ASU 100 includes a delivery zone 80 for supplying air to spray booth in a laminar flow by maintaining the temperature and relative humidity thereof.

Figure 1b shows a schematic diagram of the encircled humidifier chamber section 40 marked as B in Fig. 1a. It includes eliminator plate bank 32, water supply headers 42 with piping or raisers 44 fitted with nozzles 46 for fine spraying of water pumped by the water supply pump 48 located outside the ASU 100. Air quantity to be dehumified enters the burner section 10 passing through the door 45. On weekly offs, when ASU 100 is not operating, the muck settled at the bottom of the tank needs to be removed, otherwise it will choke the orifices of the nozzles 46, affecting the required relative humidity of the air flowing therethrough to be subsequently supplied air to spray booth and the painting defects in the finished painted body shells increase substantially. This muck removal involves rigorous cleaning activity of the water tank normally conducted on weekly-offs by sending an associate inside the water spray chamber. The entry into the water spray chamber is through a single small marine window, which becomes a confined space, necessitating compliance with legal provisions mandatory therefor, to ensure the safety of this cleaning associate to carry out such cleaning work. The position D is the location of the area, where the improvements can be carried out in accordance with the present invention by providing a separate door.

Figure 1c shows a schematic diagram of the conventional eliminator plate bank 32 including six (6) subsections 1, 2, 3, 4, 5, 6 and having an overall dimension of 8 m x 6 m. It forms a wall each on either side of the raiser pipes to avoid any water particles to flow along with the air flowing into ASU 100.

Figure 2a shows an actual existing (conventional) eliminator plate bank 32 inside the humidity chamber section 40 of the air supply unit 100 of spray booth in a paint shop. These eliminator plates 32 form walls on either side of the humidity chamber and allows air coming from pre-filters to pass therethrough.

Figure 2b shows a schematic diagram of the eliminator plate section 130 configured in accordance with the present invention having six (6) subsections 11, 12, 13, 14, 15, 16; section 15 has a separate door 134 in portion 15a thereof.

Figure 2c shows a single separate door 134 provided in the eliminator plate bank 130 of Fig. 2b. This door 134 is provided to open inside the pre-filter section 120 for performing the cleaning activity, preferably on weekly-offs, of the humidity chamber of air supply units 100 of the spray booth in an automotive paint shop.
Figure 2d shows a separate door 134 of Fig. 2c provided to be fitted in the eliminator plate bank of Fig. 2b. It is fitted in a door frame 136 configured in accordance with the present invention and provided with eliminator plate fitment 138 duly aligned with the existing eliminator plates 32. The preferable size of this separate door 134 of steel box section of 50 mm is 790 x 1870 mm. It has hinges 135 on one side thereof for opening and closing the same. It also has two locking arrangements 1342 with wing nuts and a door handle 1344 fixed therebetween. So, the door 134 is opened for conducting the cleaning activity inside the humidity chamber of the air supply units 100 and closed after this cleaning activity is completed. The uniqueness of the present invention is supplying air flow to spray booth at a rate of about 163800 m3/hour.

Figure 2e shows a schematic diagram of the humidifier chamber section 140 having an air inlet door 145 and equipped with an additional separate door 134 configured in accordance with the present invention and opening inside the pre-filter section 120. It includes eliminator plate bank 132, water supply headers 142 with piping or raisers 144 fitted with nozzles 146 (not shown) for fine spraying of water pumped by the water supply pump 148 located outside the ASU 100. Air quantity to be dehumified enters through the door 145 into the burner section 10. A separate door frame 136 with the profile similar to eliminator plates 132 is fitted in these existing plates 132 by means of hinges 135, which can be opened for performing the cleaning activity of the tank and closed after this cleaning activity is over. This door 134 eliminates any disturbance of air flow, while flowing over this door 134 inside the humidifier chamber section 40.

Figure 3 shows a graphical representation of the number of permits per year granted for cleaning of confined spaces in ASUs. Accordingly, the number of permits granted per year has reduced from 140 nos. prior to the calendar year 2016 to 0 (zero) after the introduction of the eliminator plate section 130 configured in accordance with the present invention.
DESCRIPTION OF THE INVENTION

The eliminator plate section configured with a single separate door in accordance with the present invention requires modifications only in the LNG supply pipe, filter section area, platform on the tank with railing and fitment of the new separate leak-proof door, all of which cost only about INR 2.20 Lakh per ASU, i.e. a total cost for about 11 Lakh for all 5 ASUs. Accordingly, a separate door is fabricated within the available space in the adjacent section of the existing eliminator plates.

Therefore, it has the advantages of avoiding the restriction to air flow supplied to spray booths, avoiding water leakage from raisers from the eliminator plates and this door can be made outside and subsequently fitted to all ASUs one by one during the plant shutdown.

A separate door frame with the eliminator plates is fitted in the existing plates by means of hinges, which can be opened for performing the cleaning activity of the tank and closed after this cleaning activity is over.

TECHNICAL ADVANTAGES & ECONOMIC SIGNIFICANCE

The eliminator plate section configured with a single separate door in accordance with the present invention has the following technical advantages and economic significance:

• Eliminates “Confined Space” to avoid compliance with the legal restrictions connected therewith.

• No Permit Required, no trained First Aid provider or deep-cleaning supervisor required while performing the Cleaning Activity.

• Does not require any Oxygen level monitoring, safety life-line or canister cylinders for emergency situations.

• Eliminates any unsafe working conditions by providing a separate single door for easy access in addition to the Small Marine Window.
• Substantially reduced cost of human resources required for the cleaning activity, e.g. savings of about INR 78000 per year Saved.

• Boosts the safety and thus moral of the Cleaning staff.

• Deployable across all painting shops in manufacturing industries, e.g. automotive paint-shops.

• Deployable in all other industries using Air Supply Units for providing conditioned air, e.g. Pharma and Cotton processing industries.

• Does not disturb the laminar flow inside the spray booth, creating the overspray defects on paint process.

• No water leakages, no defects are observed during the spray painting process.

• Allows no Leakages from the door frame fitment, thus no rust is observed inside the Air Supply Unit and other parts thereof.

• Fitment and dismantling of the door is easy by providing M12 wing nuts.

• Uses Stainless Steel door (box section 50 mm x 1870 mm X 790 mm).

• Uses eliminator plates of adjacent sections on door frame instead of sheet, thus avoiding water leakages problems.

• Avoids painting quality concerns as the overspray is eliminated during the paint spraying process.

• Arrangement is easy to open and close.

• Overall eliminator plate section dimension of 8 m x 6 m.

• Separate door installed inside the eliminator Plates section is 1.87 m high and 0.790 m long.

• Providing a separate second door into the humidity chamber does not affect the technical properties of the air supplied to the spray booths eliminates the compliance issues related to the “Confined spaces”.

• No need of for a new door fitment, so no disturbance in the layout of the Air Supply Units.

• Uses the available area and door is made door without disturbing the function of the humidifier section.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

The description provided herein is purely by way of example and illustration. The various features and advantageous details are explained with reference to this non-limiting embodiment in the above description in accordance with the present invention. The descriptions of well-known components and manufacturing and processing techniques are consciously omitted in this specification, so as not to unnecessarily obscure the specification.

It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, the skilled person will recognize that the embodiments herein can be practiced with modification within the spirit and scope of embodiments described herein.

Therefore, the skilled person can easily make innumerable changes, variations, modifications, alterations and/or integrations in terms of materials and method used to configure, manufacture and assemble various constituents, components, subassemblies, assemblies and in terms of the size, shapes, orientations and interrelationships without departing from the scope and spirit of the present invention.
The numerical values given of various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the disclosure unless there is a statement in the specification to the contrary.

Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising”, shall be understood to implies including a described element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps.

The use of the expression “a”, “at least” or “at least one” shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention. ,CLAIMS:We claim:

1. An arrangement for safely cleaning the water tank of air supply unit (ASU) of spray painting booth in an automotive paint shop, the arrangement comprising a plurality of subsections including burner section (110), pre-filter section (120), eliminator plate gallery (130) having eliminator plate bank (132), humidifier section (140), fan room (150), sound damper section (160), post-filter section (170), and delivery zone (180); characterized in that a separate leak-proof door (134) is configured with a profile similar to said eliminator plates of said eliminator plate bank (132), said door (134) adapted to be opened to perform the cleaning activity of the water tank and to be closed after completion of said cleaning activity for eliminating any disturbance in air flow over said door (134).

2. Arrangement as claimed in claim 1, wherein said door is provided in the humidifier subsection (140) and facing said pre-filter section (120).

3. Arrangement as claimed in claim 1, wherein said door opens inside said pre-filter section (120) for an automatic closure thereof during said cleaning activity due to the air-flow entering said burner section (110) through a door (145) provided therein and subsequently hitting said door on entering said pre-filter section (120).

4. Arrangement as claimed in claim 1, wherein said separate leak-proof door (134) comprises a plurality of hinges (135) on one side length thereof, at least a pair of locking arrangement (1342) with respective wing nuts, and a door handle (1344) fitted therebetween for opening and closing thereof.

5. Arrangement as claimed in anyone of the claims 1 to 4, wherein said separate leak-proof door (134) is fitted on the existing eliminator plate bank by modifying only the LNG supply pipe, filter section area, platform on the water tank with railing and eliminator plate fitment thereof.

6. Arrangement as claimed in anyone of the claims 1 to 5, wherein said burner section (110) maintains the required temperature, preferably at 24-260C by heating ambient air, more preferably by using LNG gas entering through said door (145) provided therein.

7. Arrangement as claimed in anyone of the claims 1 to 6, wherein said pre-filter section (120) comprises coarse media bag filters for arresting the dirt and dust particles present in air supplied to said air supply unit (ASU).

8. Arrangement as claimed in anyone of the claims 1 to 7, wherein said eliminator plate gallery (130) is configured of eliminator plates (132) arranged in a 3-pass system, said gallery (130) forming a respective wall on either side of said humidifier section (140) for eliminating water droplets present in the air flowing therethrough.

9. Arrangement as claimed in anyone of the claims 1 to 8, wherein said separate leak-proof door (134) is made of 50 mm steel box section, preferably of 790 mm x 1870 mm.

10. Arrangement as claimed in anyone of the claims 1 to 9, wherein said water tank of air supply unit (ASU) of spray painting booth comprises an air-entry door (145) and said separate leak-proof door (134) to avoid creation of any confined space therein due to easy access and exit from said water tank for the personnel performing said cleaning activity, and thereby does not require any legal compliance.

Digitally Signed.

Dated: this day of 09th August 2017. SANJAY KESHARWANI
APPLICANT’S PATENT AGENT