Kitchen ventilation degreasing system
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.
The present application derives priority from Provisional Patent Application No. 60/534,325 filed Jan. 5, 2004.
BACKGROUND OF THE INVENTION1. 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 INVENTIONIt 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 FIGURESThe following figures are illustrative of the preferred embodiment of the present invention:
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 (
The kitchen ventilation degreasing system according to the present invention includes two main components, a cleaning mechanism 10 (described below with reference to
Referring to
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.
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.
Referring back to
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.
With reference to
The top support arm 20 is secured to a supporting structure at the exhaust end 5 (See
Referring back to
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.
With combined reference to
Also, in this particular embodiment (illustrated in
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
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
Referring to
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
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
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
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.
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.
Type: Application
Filed: Jan 5, 2005
Publication Date: Aug 18, 2005
Inventors: John Marshall (Fallston, MD), Joe Way (Abingdon, MD), Keith Lipford (Severna Park, MD), Brian Lipford (Bel Air, MD)
Application Number: 11/029,994