Title:
Kitchen ventilation degreasing system
Kind Code:
A1


Abstract:
The present invention is a permanently installed automatic kitchen ventilation degreasing system. The system includes a cascading cleaning mechanism and drainage mechanism. A water feed tube carries water and cleaning agents to a conduit secured and centered within the ventilation ducts. The water and cleaning agents are sprayed in a cascading manner along the inner surface of the duct by spray nozzles located on nozzle blocks spaced at intervals along the conduit. The flow of solvent or rinse water through the nozzles is controlled by solenoid valves which are controlled by a programmable controller. The liquid run off is collected by a deflector and drained.



Inventors:
Marshall, John (Fallston, MD, US)
Way, Joe (Abingdon, MD, US)
Lipford, Keith (Severna Park, MD, US)
Lipford, Brian (Bel Air, MD, US)
Application Number:
11/029994
Publication Date:
08/18/2005
Filing Date:
01/05/2005
Assignee:
MARSHALL JOHN
WAY JOE
LIPFORD KEITH
LIPFORD BRIAN
Primary Class:
Other Classes:
126/299R
International Classes:
F24C15/20; (IPC1-7): F24C15/20
View Patent Images:
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Primary Examiner:
SUERETH, SARAH ELIZABETH
Attorney, Agent or Firm:
OBER/KALER c/o Royal W. Craig (Baltimore, MD, US)
Claims:
1. A ventilation degreasing system for cleaning the interior surfaces of a kitchen ventilation duct, comprising: a duct conduit in fluid communication with a water source, and a cleaning solution source, said duct conduit comprising a plurality of conduit segments attached to a corresponding plurality of nozzle blocks, each nozzle block having a plurality of nozzles, the duct conduit extending substantially the length of said ventilation duct; a programmable controller connected to a plurality of solenoid valves for controlling distribution of cleaning solvent or water into said duct conduit and to said nozzles; a drainage assembly for or capturing liquid run-off in said kitchen ventilation duct during operation of said degreasing system; and a plurality of support arms for supporting said duct conduit centrally in the kitchen ventilation duct.

2. The ventilation degreasing system according to claim 1, wherein each of said duct centering support arms comprises distal rollers at each end, and a spring mechanism for imparting lateral spring between said rollers.

3. The ventilation degreasing system according to claim 1, wherein said cleaning solution source comprises a venturi inlet connected to a cleaning solution reservoir and to said water source for inducting cleaning solution into said duct conduit.

4. The ventilation degreasing system according to claim 1, wherein said drainage assembly comprises a deflector formed from a metal sheet with an upper portion that hooks over an existing removable filter in said kitchen ventilation hood to thereby anchoring the deflector inside the kitchen ventilation system.

5. The ventilation degreasing system according to claim 1, wherein said drainage assembly comprises a catch basin beneath the kitchen ventilation system with a drain pipe connected thereto for drainage into a removal vessel.

6. A ventilation degreasing system for cleaning the interior surfaces of a kitchen ventilation duct, comprising: a multi-stage duct conduit in fluid communication with a water source, and a cleaning solution source, said multi-stage duct conduit comprising at least an upper stage duct conduit with a plurality of nozzle blocks and associated nozzles supported inside said kitchen ventilation duct along an upper extent thereof, and a lower stage duct conduit with a plurality of nozzle blocks and associated nozzles supported inside said kitchen ventilation duct along a lower extent thereof; the multi-stage duct conduit collectively extending substantially the length of said kitchen ventilation duct; a programmable controller connected to a plurality of solenoid valves for selectively controlling distribution of cleaning solvent or water into one of said upper or lower stages of said multi-stage duct conduit and out from the nozzles thereof.

7. The ventilation degreasing system according to claim 6, wherein each of said duct centering support arms comprises distal rollers at each end, and a spring mechanism for imparting lateral spring between said rollers.

8. The ventilation degreasing system according to claim 6, wherein said cleaning solution source comprises a venturi inlet connected to a cleaning solution reservoir and to said water source for inducting cleaning solution into said duct conduit.

9. The ventilation degreasing system according to claim 1, wherein said drainage assembly comprises a deflector formed from a metal sheet with an upper portion that hooks over an existing removable filter in said kitchen ventilation hood to thereby anchoring the deflector inside the kitchen ventilation system.

10. The ventilation degreasing system according to claim 6, wherein said drainage assembly comprises a catch basin beneath the kitchen ventilation system with a drain pipe connected thereto for drainage into a removal vessel.

11. A ventilation degreasing system for cleaning the interior surfaces of a kitchen ventilation system inclusive of ventilation duct and hood, comprising: a duct conduit in fluid communication with a water source and cleaning solution source, said duct conduit comprising a plurality of nozzle blocks and associated nozzles supported inside said kitchen ventilation duct and extending substantially the full length of said kitchen ventilation duct; a hood conduit in fluid communication with said water source and cleaning solution source, said hood conduit comprising a plurality of nozzle blocks and associated nozzles supported inside said kitchen ventilation hood and extending substantially the full length of said kitchen ventilation hood; a programmable controller connected to a plurality of solenoid valves for selectively controlling distribution of cleaning solvent or water into one of said duct conduit and hood conduit and out from the nozzles thereof.

12. The ventilation degreasing system according to claim 11, further comprising a duct support framework for supporting said duct conduit centrally and vertically in said duct, and a hood support framework for supporting said hood conduit centrally and horizontally in said hood.

13. The ventilation degreasing system according to claim 12, wherein said duct support framework includes a plurality of support arms for supporting said duct conduit centrally in the kitchen ventilation duct.

14. The ventilation degreasing system according to claim 13, wherein each of said plurality of support arms comprises distal rollers at each end, and a spring mechanism for imparting lateral spring between said rollers.

15. The ventilation degreasing system according to claim 11, wherein said cleaning solution source comprises a venturi inlet connected to a cleaning solution reservoir and to said water source for inducting cleaning solution into said duct conduit.

16. The ventilation degreasing system according to claim 11, further comprising a drainage assembly for draining runoff cleaning solution and water into a disposal vessel.

17. The ventilation degreasing system according to claim 16, wherein said drainage assembly comprises a deflector formed from a metal sheet with an upper portion that hooks over an existing removable filter in said kitchen ventilation hood to thereby anchoring the deflector inside the kitchen ventilation system.

18. The ventilation degreasing system according to claim 17, wherein said drainage assembly comprises a catch basin beneath the kitchen ventilation system with a drain pipe connected thereto for drainage into a removal vessel.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application derives priority from Provisional Patent Application No. 60/534,325 filed Jan. 5, 2004.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the field of spray applicators for cleansing the interior surfaces of enclosed spaces and, more particularly, to a fully automated spray degreasing system for cleansing elongated enclosed spaces such as in kitchen ventilation systems and the like.

2. General Background

Kitchen ventilation ducts are typically required by code to remove smoke, air borne grease, and by-products of cooking from commercial kitchen areas and particularly from the area directly over the stove-tops. However, air-borne grease as it cools commonly accumulates on the inside walls of the ventilation ducts, thereby creating a grease-fire hazard. Periodic degreasing of the kitchen ventilation ducts on a regular basis is recommended and, for commercial kitchens, often mandated by state and federal regulations.

Traditionally, degreasing kitchen ventilation ducts is accomplished by snaking high pressured hot water jetting nozzles into a duct and hand directing the cleaning. This method requires multiple individuals to accomplish the task and is typically done after normal working hours thereby requiring extra staff to remain after normal closing hours. The process is cumbersome, messy and typically exposes workers to hazardous chemicals. In addition, visibility within the duct is minimal and verification of adequate surface cleaning is difficult. Fluid run off is typically collected into sheets beneath the flue, directed in to buckets and drained or manually cleaned-up from the floor.

There have been past efforts to develop automatic cleaning devices to clean ventilation ducts is disclosed in the prior art and typically involves the use of conduit permanently installed inside the ventilation duct for carrying water or cleaning fluid. The conduit is centrally-secured by multiple struts, and water or cleaning fluid is discharged under pressure towards the duct walls either directly through a plurality of holes in the conduit or through some other mechanism (i.e. sprinkler heads).

For example, U.S. Pat. No. 4,031,910 to Lawson on Jun. 28, 1977 discloses an “Articulated Spray Applicator Particularly Suited for Use in Cleaning Flues and the Like.” The conduit of the spray applicator is segmented, with the segments angularly joined such that the conduit follows an angularly configured flue. Furthermore, each conduit segment is joined together, plus mounted to the flue wall, such that simultaneous unidirectional rotation may be imparted upon each segment independently in response to the jetting action of the fluid as it is expelled. The conduit is secured to the flue using conventional support spiders. The specific structure of the support spiders and the method of securing them to the flue formed no part of the invention. As a practical matter a drip pan is placed beneath the flue to collect run off.

U.S. Pat. No. 5,860,412 to Way et al., also included among the present inventors, discloses a “Kitchen Duct Degreasing System.” This system uses a pump to both super-heat water and to deliver it under pressure through conduit installed inside the ventilation duct and out a plurality of nozzles. The nozzles are opened and closed individually by an electronic programmable timer. Multiple nozzles are placed at periodic intervals along the conduit such that when activated the entire surface perimeter of the inside of the duct is cleaned. To ensure adequate pressure the nozzles are not operated simultaneously, but rather on a rolling or cascading schedule, top to bottom. A water-tight deflector located at the bottom of the duct captures run off so that it may be directed to a suitable receptacle after degreasing. A programmable controller operates the nozzles. The conduit is fixed attached to the duct walls by any suitable means (i.e. support members under tension against duct walls, welds, bolts, epoxy adhesive, etc.) and the nozzles are fixedly attached to the conduit.

The systems described in the prior art references above, address the problems related to hand directed duct cleaning methods. However, these systems are expensive, difficult to install, difficult to operate (they are not all fully automatic), and are not entirely safe because they do not suggest a solution to prevent the escape of caustic run off, or of aerosolized cleaning solution.

Therefore, a need still exists for an effective and cost efficient approach to the problem of grease accumulation upon the interior surfaces of kitchen ventilation systems.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method and device for automatically degreasing the interior surfaces of kitchen ventilation systems.

It is another object of the present invention to provide a method and device for safely and economically degreasing the interior surfaces of kitchen ventilation systems without need for any hand held and directed equipment.

Another object of the present invention is to provide a device for effectively degreasing the interior surfaces of kitchen ventilation systems that can be permanently installed on-site, either as original equipment with installation of the ducting or retrofit into pre-existing systems.

Another object of the present invention is to provide a device for effectively degreasing the interior surfaces of kitchen ventilation systems that, depending on the length and height of the ventilation system, may be connected directly to a pre-existing water source and operate from existing pressure, thereby avoiding the need for installing an expensive water pressurization system.

Another object of the present invention is to provide a kitchen ventilation system degreasing device further having a venturi type injector connected to the water feed for injecting cleaning agent concentrates into the water stream, as needed, for more efficient degreasing of the interior surfaces of the kitchen ventilation system.

It is a further object of the present invention to provide a kitchen ventilation system degreasing device that employs the existing ventilation grease drainage assembly in a modified configuration to eliminate spray and leakage.

It is a further object of the present invention to provide secondary grease-fire suppression in addition to its cleaning capability.

It is also an object of the present invention to provide a modular design for easily and efficiently installing, centering and securing the conduit of the present invention inside the ventilation systems.

The foregoing and other objects of are accomplished by providing a kitchen ventilation system degreasing system that includes (1) a duct conduit extending the length of a kitchen ventilation duct from the intake to the exhaust, (2) a fixed top support arm mounted to the ventilation system at a point beneath the exhaust fan for suspending the conduit, (3) a hood conduit extending the full length of the existing kitchen hood; (4) one or more supports for attaching the kitchen hood conduit inside the hood; (5) a water feed pipe connected to the intake end of the conduits, (6) a venturi type injector connected to the water feed for injecting cleaning agent concentrates into the water stream, as needed; (7) a plurality of electric solenoid valves that enable distribution of water with or without cleaning agent; (8) a plurality of nozzles connected to nozzle blocks that are spaced at intervals along the conduit for spraying the water/cleaning agent; (9) a programmable controller connected to the solenoid valves; (10) duct centering support arms for securing the conduit within the kitchen ventilation system, and (11) a splash-proof run-off drainage mechanism that makes use of the existing ventilation grease-drain for draining cleaning solution and debris into a receptacle for safe code-compliant removal.

The fixed top support arm suspends the duct conduit beneath the exhaust fan, while the plurality of uniquely structured duct centering support arms each comprise a spring-bar with wheels at each end. The centering arms are attached to the conduit at predetermined intervals. The conduit is fixed through the duct centering support arms and is snaked into the kitchen ventilation system from the exhaust end of the ventilation system. As the conduit is snaked into the duct work, the wheels of the centering arms roll along the interior surfaces of the duct, and the lateral springiness of the centering arms accommodate bumps and unevenness, thereby centering and guiding the conduit. Once the conduit is in place it is fixed to the top support arm.

The hood conduit is positioned at the proper location to allow spray to impinge upon all surfaces of the existing kitchen hood behind the filters. The hood conduit is secured to the hood with support(s) attached to the hood.

The system is fully automatic, employing a plurality of electrically-controlled solenoid valves, solvent flow sensor, an optional effluent cleanliness sensor, and a programmable controller connected to each of the nozzle-valve blocks. The nozzle-blocks each employ multiple spray nozzles connected to the conduit which deliver water as well as a cleaning agent concentrate to the interior surface of the ventilation duct.

The present system is able to operate from standard water pressure and this suffices to drive the system due to (1) use of efficient spray nozzles and (2) a particular conduit/valve arrangement and cascading operation that maintains adequate pressure on all nozzles. By virtue of the foregoing the nozzles provide a spray that fully and accurately covers the targeted spray area.

A cascading operation can be accomplished by regulating the flow of water through stages of the conduit by the solenoid valves connected to the programmable controller, such that only a single stage of spray nozzles are operating at any given time. The combination of high efficiency nozzles plus cascaded operation allows the system to function without the need for an expensive water pressurization system. There are generally 2-to-4 nozzles in each nozzle block and 4 or more nozzle blocks per conduit stage. The flow of solvent or rinse water is controlled through each stage by one solenoid valve)

The liquid run-off from the degreasing process drains into the existing grease collection system, but this is modified to ensure that the system is splash-proof and drip-proof to improve safety and avoid kitchen contamination.

BRIEF DESCRIPTION OF THE FIGURES

The following figures are illustrative of the preferred embodiment of the present invention:

FIG. 1 is an isometric view of the outer surfaces of a conventional kitchen ventilation system.

FIG. 2 is an illustration of the primary components of the cleaning mechanism of the kitchen ventilation system degreasing device of the present invention, as well as the support features, with an exploded cross section of the nozzle-valve blocks including the spray nozzles.

FIG. 3 is a perspective illustration of the duct nozzle block of FIG. 2.

FIG. 4 is an exploded cross section of an exemplary venturi injector.

FIG. 5 is a front perspective illustration of the hood nozzle block of FIG. 2.

FIG. 6 is a perspective view of the hood nozzle block, hood conduit, and supports of FIG. 2.

FIG. 7 is a side view of the hood nozzle block, hood conduit, and supports of FIG. 2 and 6.

FIG. 8 is an isometric drawing illustrating one embodiment of a top support arm.

FIGS. 9 and 10 are drawings of isometric and top views, respectively, of the preferred embodiment of the duct centering support arm with the integral spring action centering mechanism.

FIG. 11 is a detailed view of the preferred wheel configuration on each end of the duct centering support arm of FIG. 9.

FIGS. 12 and 13 are side and end views, respectively, of the duct centering support arm of FIG. 9.

FIG. 14 illustrates another possible embodiment of the duct centering support arm 30.

FIG. 15 is a front view of the draining mechanism 50 of the present invention including deflector 51.

FIG. 16 is a side view of the deflector 51 and catch basin 60.

FIG. 17 is a side view of the deflector 51 with exemplary dimensions.

FIG. 18 is an isometric view of the deflector 51 showing the contours.

FIGS. 19 and 20 are an isometric view and end view, respectively, of the catch basin 60.

FIG. 21 is an isometric view of the drainage basin.

FIG. 22 is a perspective view of an exemplary filter modification in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention is described in the context of a conventional kitchen ventilation system with an exhaust end 5 and an air intake end 6 (FIG. 1), an electronically controlled exhaust fan 1 at exhaust end 5, a rectangular vertical duct 2, and a kitchen hood 3 with removable flue filters 4 at air intake end 6. In operation, the exhaust fan 1 pulls kitchen air (including smoke and airborne grease) into the hood 3 through flue filters 4, into the duct 2 and out exhaust fan 1. One skilled in the art should appreciate that the present invention can be easily adapted for use with any similar ventilation system, including systems using cylindrical or non-vertical ducting, without departing from the scope and spirit of the present invention.

The kitchen ventilation degreasing system according to the present invention includes two main components, a cleaning mechanism 10 (described below with reference to FIGS. 2-14) with support features, and a drainage mechanism 50 (see FIGS. 15-22).

FIG. 2 is a system illustration of the primary components of the cleaning mechanism 10 of the kitchen ventilation degreasing system of the present invention, as well as the support features.

Cleaning Mechanism

Referring to FIG. 2, the cleaning mechanism 10 comprises a water feed tube 11 connected through a sequence of solenoid-controlled valves V1-V7 (all housed in a valve housing 13) to multi-stage duct conduit 12 which runs the length of the ventilation duct 2 for degreasing same (FIG. 1). In addition, hood conduit 14 runs the length of the existing ventilation hood 3 for degreasing it (FIG. 1). Further, a venturi injector 18 is connected inline to the water feed 11 for injecting cleaning agents into the water flow, as necessary, to achieve the degreasing.

The illustrated embodiment includes a two-stage duct conduit 12, including upper and lower stages 12a &12b, and each stage of duct conduit 12 comprises a plurality of segments screw-coupled in series to a number of nozzle blocks 16 each having a plurality of spray nozzles 17. Preferably, each nozzle block 16 will have 4 spray nozzles 17. FIG. 3 is a perspective illustration of the nozzle block 16 of FIG. 2, inclusive of spray nozzles 17.

The illustrated embodiment also includes a hood conduit 14 in fluid communication with a number of swiveling hood nozzle blocks 26 each having a plurality of spray nozzles 27. Preferably, each swiveling hood nozzle block 26 will have two spray nozzles 27. FIG. 5 is a front perspective illustration of the hood nozzle block of FIG. 2, FIG. 6 is a perspective view in the overall context of the hood 3, and FIG. 7 is a side view. The spray nozzles 27 preferably swivel about two-axes to allow adjustment upon installation for uniform spray application inside the hood 3. This is accomplished by rotatable couplings as shown by arrows. The swiveling hood nozzle blocks 26 are supported within the hood 3 by several hood conduit supports 33 (described below in more detail).

Referring back to FIG. 2, the length of each segment of duct conduit 12 will be directly proportional (typically equal) to the smallest cross-sectional dimension of the duct 2. For example the length of each segment of duct conduit 12 on a 12″ by 12″ duct would be 12″ long, on a 12″ by 18″ duct it would also be 12″ long, but on an 18″ by 18″ duct it would be about 18″ long. In the preferred embodiment conduit segments 12 are made of standard (i.e. ⅜ inch NPT) brass piping. However, those skilled in the art will appreciate that the present invention can be easily adapted for use with other materials suitable for water distribution, including but not limited to copper and galvanized steel.

Flow of liquid (i.e. water or water containing cleaning agents) out of the nozzles 17 of the upper or lower stages of duct conduit 12, as well as the nozzles 27 of hood conduit 14, is controlled by a plurality of solenoid valves V1-V7, all of which are housed in a wall-mounted valve housing 13. In the preferred embodiment of the present invention each solenoid valve V1-V7 is a conventional electromechanical valve. All of the valves V1-V7 are electrically-connected to a conventional programmable logic controller 15 for automatic control thereby. The programmable logic controller 15 is housed in a separate enclosure (remote from valve housing 13) to protect the electronics and for code compliance.

The water feed tube 11 is connected to a conventional water source (i.e. existing tap plumbing) for most kitchen ventilation systems. In order for the spray nozzles 17, 27 to function properly the water pressure must be a minimum of 15 PSI at each nozzle. Those skilled in the art will recognize that this minimum required PSI may vary depending on the type of spray nozzle used. One skilled in the art will also understand that larger kitchen ventilation systems may require more pressure than can be mustered from the existing plumbing, in which case a supplemental water pressurization system is required (any of a wide variety of existing pumps with or without accumulator tanks will suffice). Once the water source is activated, water flows from the water feed tube 11 through the valves V1-V7 in valve housing 13 and into the two-stage duct conduit 12, as well as the hood conduit 14.

A concentrated cleaning agent or solvent 70 of a type designed to cut grease, is introduced into the system by insertion of a feed tube 71 into the cleaning solution, and opening a check valve 72 as shown.

In operation, the programmable controller 15 is programmed to apply the cleaning agent 70 throughout the ventilation degreasing system, wait a predetermined time for cleaning to occur, and then rinse. This cycle can be repeated as desired. Each cleaning agent then water application is preferably cascaded from top down, upper stage of duct conduit 12a first, and then lower stage(s) 12b to reduce pressure losses. Next, the cleaning agent/water applications are applied through hood conduit 14 to degrease the kitchen hood.

During the initial application of cleaning agent 70, the programmable controller 15 opens the normally-closed input valve V3, and opens the normally-closed diverter valve V5, thereby diverting water through venturi injector 18. The venture injector 18 inducts cleaning agent 70 into the water flowstream which continues into the two-stage duct conduit 12, and into conduit 14. The controller 15 selectively opens the normally-closed staging valves V1, V2 or V7 in order to divert water/cleaning agent into the desired upper stage 12a, and then lower stage 12b, and then hood conduit 14 per the cascaded operation. Spray is emitted from the upper most nozzles 17 first, and this valve configuration is maintained for a predetermined length of time in order to completely wet the interior surface area 19 of the duct 2 immediately surrounding the upper most nozzles 16. After the predetermined length of time has passed, the staging valve V1 closes and the next valve V2 opens to supply water and solvent to the next lower stage of nozzles and so on (for as many stages as necessary). This sequential cascading supply of water/cleaning agent to the successive stage of nozzles 16 in a top down manner ensures that the water and solvent in the duct conduit 12 maintains sufficient water pressure (i.e. min 15 PSI at each nozzle) so that the entire interior surface 19 of the duct 2 is wet down with cleaning solution.

After the cleaning agent is applied to duct 19, valve V7 is opened and cleaning agent is applied throughout conduit 14 to hood 3 for a predetermined length of time. The cleaning agent is here sprayed uniformly onto the hood 3 surfaces behind the filters 4 (typically four removable filters) through swiveling hood nozzle blocks 26 and nozzles 27. Depending on the length of the hood 3, this spraying operation may require staging as well. To maintain sufficient pressure at each nozzle 27, the number, spacing and location of the nozzle swivel blocks 26 can be varied depending on the dimensions of the hood 3 and the spray angle of the nozzles 27.

Depending on the type of cleaning agent used, the cleaning agent is allowed to set on the interior surface 19 of duct 2 and inside hood 3 for a predetermined length of (approximately ten minutes or so), and the process is repeated with only water (valve V5 closes and V6 is opened by controller 15). The programmable controller 15 then opens and closes valves V1, V2 and V7 in the same cascading manner, described above, to ensure complete rinsing of the cleaning agent from the interior surface 19 of the duct 2 as well as the interior surface of the hood 3. If desired, the degreasing process may be assisted by using hot tap water or by directing tap water through a water heater or super-heater (not shown) prior to entering water feed 11.

FIG. 4 is an exploded detailed cross section of the preferred venturi type cleaning agent injector 18 of the present invention. This type of injector is integrated into the water feed tube 11 as shown in FIG. 2. In operation, as water flows through the injector 18 it is constricted inwardly of the injector chamber 73 and changes into a high velocity stream. The increased stream velocity through the injector chamber causes a pressure differential, creating a vacuum that sucks the cleaning agent 70 into the water flow. An electrical or mechanical valve 72 may be installed to turn on or off addition of cleaning agents, as necessary.

Support Features

With reference to FIG. 2, the cleaning mechanism 10 includes three types of support components: (1) the top support arm 20, and (2) at least one duct centering support arm 30 (two are shown); and several hood conduit supports 33.

The top support arm 20 is secured to a supporting structure at the exhaust end 5 (See FIG. 1) adjacent to exhaust fan 1 such that when the duct conduit 12 is attached to top support arm 20. The duct conduit 12 hangs vertical and is centered within the walls of the duct 2. The top support arm 20 spans the existing duct 2 near its uppermost edge adjacent to the exhaust fan 1, and may be fixed to the duct 2 by any suitable attaching means (i.e. bolted, welded, etc.).

FIG. 8 illustrates one embodiment of top support arm 20. In this embodiment top support arm 20 includes a rectangular spacer block 21 with a center through bore 22 (alternatively, two spaced blocks). The diameter of the center through bore 22 is approximately equal to the outer diameter of duct conduit 12, such that the duct conduit 12 inserted into the through bore 22 sits securely. Once the duct conduit 12 is inserted into through bore 22, a collar 23 is secured to the duct conduit 12 immediately above the top support arm 20 to prevent the conduit from slipping downward. The top arm 20 further includes two symmetrical elongated rigid struts (or brackets) 24. These struts are secured to (i.e. by welding, bolting, etc.) the opposing vertical planes of rectangular block 21 (sandwiching them), such that the elongated struts 24 are oriented perpendicular to through bore 22. Both ends of each elongated strut 24 are angled (right angle) outward, so that the shape of top support arm 22 forms essentially an I-bar. The angled ends 25 form a surface for securing the top support arm 22 to the ducting 2 (i.e. by welding, bolting, etc.).

Referring back to FIG. 2, the duct centering support arms 30 are designed to ensure that duct conduit 12 remains centered and secure within duct 2, and yet allow for heat expansion and contraction. Depending on the length of the duct 2 and the number of duct conduit 12 segments used, a particular ventilation system may need more than one duct centering support arm 30. Optimally, a duct centering support arm 30 should be attached at its center point 35 to the conduit at every unsupported length of duct conduit 12 exceeding approximately 20 feet. Also, an additional duct centering support arm 30 should be installed whenever there is a change in the size or angle of duct 2. The length of the duct centering support arm 30 is approximately equal to the width of the interior dimension of the duct. If the duct is cylindrical in shape then the length of the duct centering support arms is approximately equal to the inner diameter of the cylinder. If the duct is rectangular in shape then the length of the centering support is approximately equal to two opposing corners. Each duct centering support arm 30 is further comprised of lateral springs that allow the length of the duct centering support arm 30 to increase or decrease as the duct 2 expands and contracts with varying temperature. In addition, each duct centering support arm 30 is equipped with an opposing wheel mechanism 40 at each end 33.

FIGS. 9-13 collectively illustrate a preferred embodiment of a duct centering support arm 30. Each duct centering support arm 30 is further comprised of spring arms 31 that allows the length of the duct centering support arm 30 to increase or decrease as the duct 2 expands and contracts with varying temperature. The duct centering support arm 30 of this embodiment is comprised of two essentially M-shaped symmetrical elongated rigid metal straps 36 each with two ends 33, a center point 35 and 2 distal points 37. The ends 33 and center points 35 run parallel and adjacent to each other for some length. The center points 35 are attached by any suitable means (i.e. welding, bolting, etc.). The spring arms 31 allow the duct centering support arms 30 to remain in constant contact with the interior surfaces 19 of the duct 2, thus keeping the duct conduit 12 centered.

FIGS. 9 and 10 are isometric and top views, respectively, of the preferred embodiment of the duct centering support arm 30 with the integral spring action centering mechanism, and FIG. 13 is an end view, respectively, of the duct centering support arm of FIG. 9.

In addition to the spring arms 31, each duct centering support arm 30 is equipped with an opposing wheel mechanism 40 at each end 33.

FIGS. 11-12 illustrate the manner of attaching the ends 33 of the two straps 36 to incorporate wheel mechanism 40. The wheel mechanism 40 includes a horizontally attached clevis pin 41 on to which is secured a vertical wheel 42.

With combined reference to FIGS. 9-12, the ends 33 of straps 36 are aligned and each include a through bore. Inserted between the interior surfaces of the straps 36 are two interior flat washers 44 aligned with the through bores. Inserted and centered between the two interior flat washers 44 is a wheel 42. Also aligned with the through bores are two exterior flat washers 45 on each strap 36. A clevis pin 41 is inserted into through bore and secures the aligned features 33, 42, 44 and 45. The clevis pin 41 is then secured by cotter pin 46. In this particular embodiment (illustrated collectively in FIGS. 6-10), the duct centering support arm 30 may be attached to the duct conduit 12 by any suitable attaching means (i.e. a collared bracket).

Also, in this particular embodiment (illustrated in FIGS. 9-12), the preferred material and thickness for the duct centering support arm is 16 gauge galvanized steel with a 2″ width. Due to its strength and flexibility, as well as its suitability for use in conjunction with water, galvanized steel or other non-corrosive material is the preferred material used in making the duct centering support arms 36. The preferred material for the wheel mechanism 40 components is zinc plated steel. However, those skilled in the art will appreciate that there are many suitable materials. This unique configuration of two opposing symmetrical M-shaped straps 36, in combination with the strap dimensions and material, forms an integral spring mechanism 31.

In operation, if the duct 2 contracts, then pressure is exerted against end 33 which causes straps 36 to bend at distal points 37 to accommodate the contraction. As the duct 2 expands, pressure against ends 33 is decreased and the straps 36 flex at distal points 37. This continuously centers and supports duct conduit 12 within duct 2.

In operation the duct centering support arms 30 are secured to the duct conduit 12 prior to installing the duct conduit 12 into the duct 2. As the duct conduit 12 is lowered into the duct 2 from the exhaust end of the ventilation system, the wheels 42 of the attached duct centering support arms 30 roll along the interior surface 19 of duct 2. This ensures that the duct conduit 12 remains centered within the duct 2 as it is being installed.

An alternative embodiment of duct centering support arm 130 is illustrated in FIG. 14. A threaded cross fitting 137 connects the duct conduit 12 to the duct centering support arm 130. The duct conduit 12 is inserted through and secured vertically in the cross fitting 137. The duct centering support arm 130 is comprised of two hollow cylindrical beams 136. Each beam 136 has a threaded end 138 and a wheeled end 133 with a wheel mechanism 140. The threaded end 138 of each beam is threaded into the threaded cross fitting 137 such that the wheel 142 on the opposite end 133 aligns vertically. The beam 136 at the wheeled-end 133 is cut with two opposing channels 139 of some length to accommodate vertical wheel 142. A fixed pin 143, extending across the horizontal diameter of beam 136 at each end 133, acts as an axle for wheel 142. In order to accommodate a spring mechanism 131, hollow beam 136 may be further comprised of two telescoping hollow beams 136a (including the threaded end 138) and 136b (including in the wheeled end 133). A spring (not shown) within beam 136a, allows the beam to telescope out and in depending on the pressure exerted by the duct 2 against the ends 133.

Inside the hood 3, conduit supports 33 are required to secure hood conduit 14 to the hood 3. The hood conduit supports 33 are best shown in FIG. 5. A clamping device including clamping sections 150 and 151 is bolted around conduit 14 to secure the conduit 14 in correct position. Clamp section 151 connects to a rod 152 (which may be threaded or otherwise adjustable in length), which is in turn connected to a base plate 153. Baseplate 153 is secured to hood 3 by welding or by bolts.

Draining Mechanism

Referring to FIGS. 15-18, the draining mechanism 50 of the preferred embodiment of the present invention includes a deflector 51 and a catch basin 60 which empties through a drain pipe 52 to a removal vessel (not shown). Both the deflector 51 and catch basin 60 may be retrofit to the existing ventilation system at the intake end 6 (as depicted in FIG. 1).

FIG. 15 is a front view of the draining mechanism 50 of the present invention including deflector 51, and FIG. 16 is a side view of deflector 51 with a catch basin 60.

Deflector 51 is formed from an essentially rectangular sheet of metal with an upper portion 53 that hooks over the existing removable filter 58 at the intake end 6, thereby anchoring the deflector 51 inside the ventilation system. The deflector 51 is formed with a louvered central section that angles inward and away from the filters 58. The deflector 51 prevents cleaning agent, water and/or debris from escaping outward through the filters 58, and ensures that it drains downward into the existing ventilation system gutter 67.

In the preferred embodiment of the present invention the deflector 51 is made of a single piece of stainless steel bent, cut and/or molded to the desired shape. However, it will be obvious to one skilled in the art that the deflector 51 may be constructed with other appropriate materials and/or with multiple attached pieces. As seen in FIG. 15, a plurality of horizontal cuts may be made in the metal with the upper edge of the cuts pushed inward some distance, forming a plurality of horizontal louvers 57.

FIG. 17 is a side view of the deflector 51 with exemplary dimensions, and FIG. 18 is a perspective view to show the contours. The deflector 51 is attached to the hood 3 at the air intake end 6 (See FIGS. 1 and 16) of the ventilation system behind the flue filters 58. In the preferred embodiment deflector 51 is attached to hood 3 such that it is oriented at an approximate 45 degree angle to the entrance of duct 2. Additionally, the deflector 51 is of such a size that when attached to hood 3 it is capable of catching all liquid-run off from the duct 2.

FIGS. 19 and 20 are a perspective view and end view, respectively, of the catch basin 60 which is attached (by welding or the like) beneath the existing gutter 67 of the ventilation system at the intake end 6 (as depicted in FIG. 16). The catch basin 60 is a simple rectangular receptacle with drainage aperture that empties through a drain pipe 52 attached thereto to a removal vessel (not shown). If necessary, the existing ventilation system gutter 67 must be perforated to empty into the catch basin 60.

In operation of the above-described draining mechanism 50, liquid run-off from the operation of the kitchen ventilation degreasing system 10 drips from the duct 2 onto the deflector 51. The slats 57 are angled to allow air flow into the duct 2 (for proper ventilation), but to prevent liquid from escaping out. Run-off continues down into the existing gutter 67 where it empties into catch basin 60 and outward through drain pipe 52. No spray or run-off is permitted to escape into the kitchen.

Referring back to FIG. 2, the controller 15 allows the cleaning system 10 to drain as well, closing valve V3 and opening valves V1, V2, V4 and V7 to a drainage conduit. The internal check valve to the cleaning solution is also closed to prevent backwash.

The above-described system also self-monitors its own effectiveness with a turbidity sensor 90 incorporated in the drainage mechanism 50 to monitor the amount of residue in the draining run-off. A turbidity sensor 90 may be incorporated as shown inline in the drainage tube or other appropriate drainage point, and is coupled to the microcontroller 15 to provide feedback of the relative amount of suspended solids in the run-off. A variety of commercially-available turbidity sensors are presently used in other contexts such as dishwasher and washing control, and suitable sensors are available from Honeywell. The turbidity sensor 90 is here used to determine whether the interior surfaces of the ventilation system are adequately clean by examining the cleanliness of the rinse water. If not, the system 100 simply repeats the above-described process until satisfactory.

An alternative drainage mechanism is shown in FIGS. 21 and 22. FIG. 21 is an isometric view of an alternate drainage basin 80 which may be more suitable for certain existing kitchen hoods 3. Some hoods 3 are equipped with a grease channel 67 for running off of the grease into an existing grease cup (not shown), which is typically suspended beneath the grease channel 67 by posts which are inserted down into keyholes in the grease cup. The drainage basin 80 is designed to replace the existing grease cup at the same location and is provided with similar hanger keyholes 81 for slidable insertion onto the existing posts. The drainage basin 80 is fabricated as a stainless steel enclosure that channels the grease and runoff down toward a discharge pipe 83. A grease baffle 82 is welded in advance of the discharge pipe 83 to prevent grease from the cooking operation (taking place below) from directly entering the discharge pipe 83. If the existing hood incorporates conventional filters 4, these existing filters 4 can be modified to prevent spray or runoff from the cleaning operation from affecting the cooking operation.

FIG. 22 is a perspective view of an exemplary filter modification in accordance with the present invention. Typically, four filters 4 are seated in frames in the hood 3, and a small void exists between adjacent filters. A stainless steel plate 90 is attached lengthwise along one side of each filter 4 to span this void. The plate 90 is located behind the filters 4 and will not affect seating in the frame, and yet it covers the void to prevent effluent from leaking between adjacent filters 4. Note also that existing filters 4 are equipped with a series of holes 91 for flow there through, and with the foregoing modification the diameter of these holes 91 should be increased to accommodate the increased flow. Thus, during the cleaning operation the effluent will flow across the inside face of the filters 4 into the grease channel 67 (FIG. 21), down the slope of the grease channel 67 and into the drainage basin 80, and out through the discharge pipe 83 where it can be directed into an existing grease trap or otherwise, as desired.

It should now be apparent that the foregoing device excels at automatically degreasing the interior surfaces of kitchen ventilation systems both safely and economically without need for any hand held and directed equipment. The device can be permanently installed on-site, either as original equipment with installation of the ducting or retrofit into pre-existing systems, and can be connected directly to a pre-existing water source to operate from existing pressure, thereby avoiding the need for installing an expensive water pressurization system.

Having now fully set forth the preferred embodiment and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that the invention may be practiced otherwise than as specifically set forth in the appended claims.