Abstract:
A system includes an intake, an exhaust, and an adjustable directing member. The intake is for taking in air, the exhaust is for exhausting air, and the adjustable directing member is positioned for directing exhaust air toward the intake. Another aspect is a system that includes a source of polluted air and an air cleaning system. The air cleaning system includes an intake, an exhaust, and a directing member. The intake is for taking in polluted air and the exhaust is for exhausting air. The directing member is for directing air from the exhaust toward the intake to provide an air screen for keeping the polluted air in the vicinity of the intake.

Description:
FIELD 
     This patent application generally relates to a recirculating, self-contained ventilation system. More particularly it relates to recirculating ventilation system for commercial electric counter-top cooking and heating appliances. 
     BACKGROUND 
     Fixed building ventilation systems for installation over groupings of cooking equipment pieces have required ventilation ductwork extending to the exterior of the building, often with the ductwork extending through multiple floors. In addition these systems have required make up or return air ducted back to the vented areas. Such systems required considerable expense and have been complex to install and maintain in buildings. 
     In some cases small electric cooking equipment has been positioned away from the kitchen spaces and has not been vented. In these cases additional risk of fire is created or that moisture, heat, smoke, odor or grease laden air will pollute the air and create an unhealthy or uncomfortable condition for workers or patrons. A complicating condition when localized venting equipment has been used in such situations has been that breezes or air conditioning causes air movements that can interfere with capture of polluted air generated by the cooking appliance, and allow the smoke, particulates, heat, and grease laden polluted air to be released into the room. 
     A better way to vent an individual piece of cooking equipment has become desirable, and this solution is provided by the following description. 
     SUMMARY 
     One aspect of the present patent application is a system that includes an intake, an exhaust, and an adjustable directing member. The intake is for taking in air, the exhaust is for exhausting air, and the adjustable directing member is positioned for directing exhaust air toward the intake. 
     Another aspect is a system that includes a source of polluted air and an air cleaning system. The air cleaning system includes an intake, an exhaust, and a directing member. The intake is for taking in polluted air and the exhaust is for exhausting air. The directing member is for directing air from the exhaust toward the intake to provide an air screen for keeping the polluted air in the vicinity of the intake. 
     Another aspect is a system that includes an appliance and a free standing recirculating ventilation system. The appliance produces polluted air. The free standing recirculating ventilation system takes in the polluted air, filters the polluted air, and exhausts air that has pollution removed. 
     Another aspect is a system that includes a plurality of capture hoods and a hood supporting unit. Each of the plurality of capture hoods has a hood portion and a connection portion. The connection portion is for connection to the hood supporting unit. The hood supporting unit is capable of connecting to just one of the plurality of capture hoods at a time. The hood portions of the plurality of capture hoods have different shapes. The connection portions of the plurality of capture hoods are identical so any one of the plurality of capture hoods can connect to the hood supporting unit. 
     Another aspect is a system that includes a recirculating ventilation system having an air curtain. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing will be apparent from the following detailed description, as illustrated in the accompanying drawings, in which: 
         FIG. 1  is a perspective view showing a recirculating ventilation system for venting an appliance located on a base and under a hood in which the base has exhaust air louvers and the hood has an air intake, and in which the exhaust air louvers are positioned to direct exhaust air towards the air intake of the hood; 
         FIG. 2  is a perspective view of a recirculating ventilation system mounted on a cart; 
         FIG. 3  is a side x-ray view of the recirculating ventilation system of  FIG. 1 ; 
         FIG. 4   a  is a side cross sectional view of the recirculating ventilation system of  FIG. 1  showing air louvers directing exhaust air towards the air intake of the hood and showing the fan and filters for cleaning the air; 
         FIG. 4   b  is a side cross sectional view of a recirculating ventilation system with a different hood showing air louvers directing exhaust air towards the air intake of the hood and showing the fan and filters for cleaning the air; 
         FIG. 4   c  is a side cross sectional view of a recirculating ventilation system similar to those of  FIGS. 4   a ,  4   b  and showing an ultraviolet light positioned in the exhaust duct; 
         FIG. 5  is a perspective view showing air flow directed from air louvers on three sides towards the air intake of the hood; 
         FIG. 6   a  is an exploded front view of the recirculating ventilation system of  FIG. 1  showing the base, the platform pan, the air louvers, the riser, the filter frame and filters, the motor, the fan, and the hood; 
         FIG. 6   b  is an assembled perspective x-ray view of the recirculating ventilation system of  FIG. 6   a;    
         FIG. 6   c  is an assembled perspective view of the recirculating ventilation system of  FIG. 6   a  with the removable access panel open and one filter removed; 
         FIG. 7  is a perspective view showing the recirculating ventilation system of  FIG. 2  with the vent capture hood removed from the connection collar; 
         FIGS. 8   a - 8   c  are perspective view showing a recirculating ventilation system with different vent capture hoods mounted to the same hood supporting unit that includes a connection collar, a riser and a base; 
         FIG. 9  is a perspective view showing a recirculating ventilation system with a vent capture hood that has adjustable louvers over the air intake; 
         FIG. 10  is a perspective view showing an elongated recirculating ventilation system; 
         FIG. 11  is a perspective view showing a recirculating ventilation system with a base having a platform pan that has an array of exhaust ports; 
         FIG. 12  is a perspective view showing a recirculating ventilation system with fireproof dampers; 
         FIG. 13  is a side cross sectional view showing a recirculating ventilation system with a fire suppressant system; 
         FIG. 14  is a side cross sectional view showing a recirculating ventilation system having filters with pressure switches and filter-in-place switches; and 
         FIG. 15  is a perspective view showing a multi-directional adjustable exhaust louver. 
     
    
    
     DETAILED DESCRIPTION 
     A recirculating, self-contained ventilation system for commercial electric counter-top cooking and heating appliances is disclosed. The system provides what is known as a “ductless hood” because no duct extends for venting to the exterior of the building housing the equipment. The system includes internal air ducts and an air handling system suitable for installation in remote areas away from locations with external venting. The air handling system provides for filtering or treatment of grease laden air, smoke, heat, moisture and odor that may be released by an appliance, such as a panini grill. The system includes an air screen that keeps polluted air in the recirculating ventilation system, or any other equpment that produces polluted air. 
     As used in this application, a recirculating ventilation system is one that has an intake and an exhaust, and air from the exhaust is directed toward the intake. 
     Appliance  20  sits on base  22  of structure  24 , as shown in  FIG. 1 . Base  22  rests on a counter top (not shown) or on cart  25  so it can be moved from place to place, as shown in  FIG. 2 . Base  22  includes as its top surface platform pan  26 , which is formed of easily cleanable and non-combustible metal, such as stainless steel, aluminum, or powder coated steel. Platform pan  26  is positioned to directly contact appliance  20  when appliance  20  sits on base  22 , as shown in  FIG. 1 . Platform pan  26  has a larger area than the footprint of cooking appliance  20  and provides a fire resistant surface for any hot items that may contact its surface. Appliance  20  can be a cooking appliance, such as a grill, a panini grill, an oven, a fryer, a warmer, a toaster, a crepe maker, a broiler, or a steamer. Appliance  20  can also be a food warming or hot food holding appliance. Appliance  20  can also be lab equipment, repair shop equipment, industrial process equipment, or an industrial process station. 
     In addition to platform pan  26 , base  22  also has side walls  30 , front wall  32 , rear wall,  34 , and sub-floor surface  36  that together provide duct  38 , as shown in  FIG. 3  and  FIGS. 4   a - 4   c . Duct  38  extends to provide air flow across base  22  from fan  40  toward exhaust  42  adjacent front wall  32  through which a portion of air from fan  40  exhausts. Sub-floor surface  36  may have access panel  38  which may have a perforated portion and side walls  30  can include venting slots  44  to exhaust another portion of this air, as shown in  FIGS. 1 and 3 . 
     Exhaust  42  of platform pan  26  is fitted with multi-directional adjustable exhaust louvers  50  from which cleansed air is released. Additional exhaust louvers  52 ,  54  may also be installed on side walls  30  of base structure  22 , as shown in  FIG. 5 . Exhaust louvers  50 ,  52 ,  54  are adjustable to directionally project air curtain  56  in front of and around cooking appliance  20  toward intake  60  of hood  70 . The directional flow of air curtain  56  in front of and around cooking appliance  20  toward intake  60  traps emissions from and polluted air around cooking appliance  20  and helps direct that polluted air toward intake  60  and within the recirculating ventilation system. Air curtain  56  enhances air and particulate capture by hood intake  60  and restricts loss of polluted air into the room as a result of breezes or air conditioning that might otherwise affect the recirculating and treatment operation. 
     Adjacent rear wall  34  of base  22  motor  72  is connected to tangential fan  40  to provide for flow of air into intake  60  and out of exhaust  42 , as shown in  FIGS. 4   a ,  4   b . Air is supplied from intake  60  through duct  74  in hood  70  that directs air through air treatment modules  75  that clean the air and provide cleaned air at tangential fan  40  for redirection into duct  38  in base  22  and to exhaust  42 . 
     Air treatment modules  75  include grease filter  76   a , particulate filter  76   b , and a deoderizing charcoal filter  76   c  for cleaning the polluted air and capturing contaminants. Grease filter  76   a  is an aluminum filter with change of direction flow to absorb heat and cool the air and to remove grease particulates. Removable grease collector  78  allows for collection and removal of accumulated grease. Other kinds of air treatment modules can also be included for the extraction or treatment of grease, particulates, steam, and for treatment of odor and heat in the air passing down through riser duct  82  towards fan  40 . For example, an electrostatic precipitator and a catalytic converter can be included. They can be installed as a part of grease filter  76   a , in addition to grease filter  76   a , or in the place of grease filter  76   a.    
     Grease filter  76   a  is available from Component Hardware Group, Lakewood, N.J. Particulate filter  76   b  and deoderizing charcoal filter  76   c  are available from Air Filters, Inc., Houston Tex. Combination filters that includes a grease filter and a catalytic converter are available from Applied Catalysts, Doraville, Ga. 
     Filter frame  90  houses each of the individual removable air treatment modules  75 , such as filters  76   a - 76   c , as shown in  FIGS. 4   a - 4   b  and  6   a - 6   c . Filter frame  90  includes directional ducting  74 ′ for providing air flow through each filer  76   a - 76   c.    
     Fan housing  80  encloses tangential fan  40  and effects the approximated 90 degree direction change in air flow at tangential fan  40 , as shown in  FIGS. 3 ,  4   a - 4   c  and  6 . Within fan housing  80  tangential fan  40  is wide enough to supply air across a majority of the width of base structure  22 , as shown in  FIG. 6   a ,  6   b.    
     Duct  38  has a first configuration and a second configuration, as shown in  FIGS. 6   a - 6   b . When duct  38  is in the first configuration it includes platform pan  26  and has its top enclosed by said platform pan  26 , as shown in  FIG. 6   b . When duct  38  is in the second configuration duct  38  has its top open. In one embodiment, platform pan  26  is removed from duct  38 , as shown in  FIG. 6   a . Enclosing and opening duct  38  with platform pan  26  allows duct  38  to go back and forth between the first configuration and the second configuration. When platform pan  26  encloses duct  38  platform pan  26  is positioned for supporting appliance  20  in structure  24 , as shown in  FIG. 1 . 
     Riser duct  82  extending from platform pan  26  toward air capture hood  70  houses motor  72 , fan  40 , fan housing  80 , and air treatment modules  75 . Riser duct  82  also includes filter frame  90 , which has filter slots  92 , as shown in  FIGS. 6   a - 6   c . Filter slots  92  support individual removable air treatment modules  75 , such as filters  76   a - 76   c . Removable access panel  94  allows access to removable air treatment modules  75  for servicing or replacement. 
     Connection collar  96  is connected between top end  98  of riser duct  82  and bottom end  100  of capture hood  70 , as shown in  FIG. 7 . Connection collar  96  may be connected to capture hood  70  and to riser duct  80  using a tool-less connector system, such as available from Tinnerman Fasteners, Brunswick, Ohio. 
     Capture hood  70  is modular and replaceable, and another one with a different size can be installed when a particular cooking appliance is replaced with one that has different characteristics, as shown in  FIGS. 8   a - 8   d . For example, intake  60   a  is located in a portion of hood  70   a  corresponding to the flow of polluted air from the front of a cooking appliance with a front opening door, such as a convection oven, as shown in  FIG. 8   a . Intake  60   b  is located in a portion of hood  70   b  corresponding to the flow of polluted air from an open topped cooking appliance, such as a flat grill or a panini grill, as shown in  FIG. 8   b . This leaves room for the operator to add or remove food items from the open topped cooking appliance. In yet another example, capture hood  70   c  is positioned lower with vertical intake slots  104  located to receive air from a cooking appliance that emits cooking air from a back wall of the appliance, such as a portion steamer, as shown in  FIG. 8   c . Connection collar  96  is positioned to receive any of capture hoods  70   a ,  70   b ,  70   c . The shape and size of capture hood  70  chosen is determined by the cooking appliance to be vented but all of them fit equally well on connection collar  96  and on riser duct  82 . 
     In one embodiment, adjustable air intake  60   d  on capture hood  70   d  permits adjusting the surface area of the air intake, as shown in  FIG. 9 . Adjustable air intake  60   d  can be used to control the velocity of air entering and provides additional control for balancing air flow. 
     Single, elongated structure  24 ′ is used for supporting and venting several cooking appliances, as shown in  FIG. 10 , and can include several tangential fans  40 . 
     Platform pan  26 ′ can have array  120  of exhaust ports  122 , as shown in  FIG. 11 . Each exhaust port  122  is defined by an edge of platform pan  26 ′. Rails  124  are used to support the cooking appliance and to provide a vertical air flow around the appliance, stripping heat from its exterior. In this case full coverage hood  60   a  would be used, and an air screen is provided by columns of air flowing straight up. 
     Fireproof dampers  126   a ,  126   b  mounted on hinges  128   a ,  128   b  can be provided in riser  82  and base  22  respectively, as shown in  FIG. 12 . Heat sensitive releases  130   a ,  130   b  automatically cause fireproof dampers  126   a ,  126   b  to close when a preset temperature is reached, interrupting the flow of air. Closing fireproof dampers  126   a ,  126   b  restricts flow of air needed for burning. Closing fireproof dampers  126   a ,  126   b  also contains a fire within the ducts where it can be extinguished with a fire suppressant. 
     Fire suppression system  140 , including fire suppression tank  142  with fire suppressant  144 , pipe  146 , and chemical spray heads  148  can be provided, as shown in  FIG. 13 . Fusible links  150  can be provided to initiate activation of fire suppression system  140 . A fire will heat at least one of fusible links  150  enough to cause it to melt and open the circuit. Power to outlet  152  for the cooking appliance is automatically disconnected when any one of fusible links  150  opens. Fire suppression system  140  is also activated when any one of fusible links  150  opens. A fire suppressant system of this type is available from Ansul Corporation. 
     Pressure switches  156  and filter-in-place switches  158  may be included to prevent operation when one of filters  76   a - 76   c  is clogged or is not in place, as shown in  FIG. 14 . 
     Filter-in-place switches  158  have a compression rocker switch. When the filter is in place the rocker is depressed closing the circuit, allowing the motor and fan to operate. When the filter is not in place the rocker is not depressed, the circuit is open and the motor and fan do not operate. Filter-in-place switches are available from Arcolectric Wes Garde, part number E3101AAAAB. 
     Pressure switches  156  have an air tube downstream from each filter. Air entering the tube depresses a micro switch closing the circuit, again allowing the motor and fan to operate. If the filter is too clogged to allow enough air to pass to enter the tube and close the switch completing the circuit, the motor and fan do not operate. Pressure switches are available from Micro Pneumatic Logic Inc., part number MPL-533-T-0.1. 
     Curved metal ducting  164  and ultraviolet light  166  can be provided in base  22 , as shown in  FIG. 4   c , to react with pollutants getting through the filters, eliminating odors. 
     Capture hood  70  includes curved portion  170  that automatically directs rising polluted air toward air intake  60 , where it is drawn in, as shown in  FIG. 4   a.    
     Multi-directional adjustable exhaust louver  50  includes curved portion  180  that automatically directs air flowing in base  22  upward and out of exhaust  42 , as shown in  FIG. 15 . Louver  50  includes handle  182  that allows an operator to easily rotate louver  50 . Multi-directional adjustable exhaust louver  50  also includes independently adjustable wing  184  that rotates around an axis perpendicular to the axis of rotation of louver  50 . Thus, an operator can direct air around two perpendicular axes. 
     While several embodiments, together with modifications thereof, have been described in detail herein and illustrated in the accompanying drawings, it will be evident that various further modifications are possible without departing from the scope of the invention as defined in the appended claims. Nothing in the above specification is intended to limit the invention more narrowly than the appended claims. The examples given are intended only to be illustrative rather than exclusive.