Abstract:
A blower for use in a kitchen ventilation system includes a set of blades driven by a motor for moving air containing cooking byproducts from a surrounding area and separating out cooking byproducts. A housing at least partially encompasses the set of blades and captures the separated cooking byproducts. A tray engages with the housing, which includes a reservoir for accumulating the captured cooking byproducts, wherein the tray is separable from the housing to allow discarding of the accumulated cooking byproducts.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/628,350, filed Oct. 28, 2012. 
    
    
     FIELD OF INVENTION 
     The present invention relates in general to kitchen ventilation systems and in particular to systems and methods for collecting and removing cooking byproducts in a kitchen ventilation system. 
     BACKGROUND OF INVENTION 
     Cooking creates undesirable by-products such as smoke, grease and odor that can pollute an inhabited airspace if they are not removed or reclaimed. Consequently, many devices have been invented for addressing the problem of airborne cooking contaminants. For example, ducted range hoods remove the contaminated air from the inhabited area, while ductless range hoods intake air from the cooking area, remove at least some of the contaminants, and then re-circulate the resulting exhaust air back into the inhabited space. 
     Grease is one particularly difficult problem to address in any type of ventilation system. Among other things, liquefied grease removed from the air can accumulate in hard-to-reach areas of the ventilation system, where it can become rancid, support the growth of fungus or bacteria, attract insects, or even present a fire hazard. The average American household typically must address over a gallon of cooking grease every year and commercial kitchens significantly more. 
     While cleaning the ventilation system of grease is mandatory for maintaining hygiene and safety, whether it is in a home or commercial kitchen, the structure and assembly of currently available ventilation systems often make removal of accumulated grease a time-consuming and painstaking task. For example, in some ventilation systems employing a blower to remove airborne grease through liquefaction, the blow unit must be accessed in the ventilation system and at least the blower housing removed and washed. While removing and washing the blow housing, the user must take care to avoid spilling grease along with particulate matter trapped within the grease. 
     SUMMARY OF INVENTION 
     According to one embodiment of the present inventive principles, a blower is disclosed for use in a kitchen ventilation system includes a set of blades driven by a motor for moving air containing cooking byproducts from a surrounding area and separating out cooking byproducts. A housing at least partially encompasses the set of blades and captures the separated cooking byproducts. A tray engages with the housing, which includes a reservoir for accumulating the captured cooking byproducts, wherein the tray is separable from the housing to allow discarding of the accumulated cooking byproducts. 
     The embodiments of the principles of the present invention advantageously allow collected grease and particulate matter to be easily and quickly removed from the blower of a kitchen ventilation system. A removable shield-assembly simply slides away from the bottom of blower housing and the accumulated cooking byproducts within the shield-tray reservoir discarded. For a more thorough cleaning of the blower unit, the blower housing can also be removed using simple latches. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a diagram of a representative cooking hood assembly, embodying the principles of the present invention, shown in a typical home cooking environment; 
         FIG. 2A  is a diagram showing a selected one of the blower units of  FIG. 1  according to the principles of the present invention; and 
         FIG. 2B  is a diagram showing the blower unit of  FIG. 2A  partially disassembled for cleaning according to the principles of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The principles of the present invention and their advantages are best understood by referring to the illustrated embodiment depicted in  FIGS. 1-2  of the drawings, in which like numbers designate like parts. 
       FIG. 1  is a diagram of an exemplary ducted hood system  100  embodying the principles of the present invention. Hood system  100  is shown disposed over a conventional home kitchen stove and grill unit  101 , which during normal cooking generates cooking byproducts including grease, odors, and smoke. While hood system  100  is shown a larger home kitchen environment, the present inventive principles are not limited thereto, and may be applied to other environments, such as commercial kitchens and smaller household kitchens. In addition to stoves, the cooking byproducts can be generated by other nearby cooking appliances, such as frying pans and similar electric apparatus. It should also be recognized that while exemplary hood system  100  is a ducted system, the principles of the present invention discussed below are equally applicable to ductless hood systems. 
     Exemplary hood system  100  includes a hood  102 , which is appropriately sized to capture cooking byproducts generated during the use of stove and grill  101 , including heat, steam, odors, and grease. The size and shape of hood  102  can vary widely, depending on the desired aesthetics, the size of the underlying appliances, the size of the kitchen, as so on. The surfaces of hood  102  exposed to stove and grill  101  are preferably metal, for example stainless steel, although the outer surfaces may be enclosed in wood, plastic, or a similar material providing the desired aesthetics. 
     Representative hood system  100  is a multiple-blower system, including two (2) pairs of back-to-back blower units  103 A and  103 B. The number of blower units  103  may vary depending on the particular application. For example, only a single blower  103  may be required to meet the ventilation requirements of a small household kitchen, while multiple blowers  103 , along with a larger hood  102 , may be required to cover multiple household cooking surfaces or commercial kitchen equipment. In each case, tradeoffs typically must be made, with hood systems with a higher airflow able to handle larger kitchen environments, at the expense of producing more noise. 
     Lights  104 A and  104 B are also included in exemplary hood system  100 , and may utilize fluorescent, incandescent, halogen or other types of standard light bulbs or tubes. Automatic dampers  105  prevent back-draft from the outside environment through the associated ducting (not shown). 
       FIGS. 2A and 2B  respectively show an assembled and partially disassembled blower unit  103  according to the principles of the present invention. Blower unit  103  includes a rear section  201  containing a motor, which drives a squirrel cage  202 . Squirrel cage  202  includes a set of blades  211  supported by a pair of rings  212 . Blades  211  are angled with respect to the axis of rotation of squirrel cage  202 . In the embodiment of  FIGS. 2A and 2B , the axis of rotation of squirrel cage  202  is generally disposed horizontally to the bottom of blower unit  103  after blower unit  103  is installed within hood system  100 . 
     In operation, squirrel cage  202  is maintained within a housing  203 , which includes an aperture  204  for receiving heated vapors and an exhaust aperture  205 , which exhausts vapors depleted of grease and particulates to the associated ducting. A latch  206  on each side of blower unit  103  allows housing  203  to be separated from rear section  201  and squirrel cage  202  to be accessed. Rear section  201  and housing  203  are preferably constructed of metal, for example, stainless steel sheeting. Together, the motor within rear section  201  and squirrel cage  202  implement two important functions: (1) ventilating the area around stove and grill  101  by evacuating air containing cooking byproducts; and (2) separating grease and particulate matter within the evacuated air through liquefaction. 
     The lower surface of housing  203  includes and aperture, shown by dashed lines in  FIG. 2B , which is covered during operation by a removable shield-tray assembly  207 . Shield-tray assembly  207  includes upward extending tabs  208  with horizontal slots for engaging corresponding posts  209  on each side of housing  203 . A reservoir (pan)  210  is provided on the upper surface of removable shield-tray assembly  207  and corresponds with the aperture in the lower surface of housing  203  for receiving liquefied grease and particulates separated from the incoming flow of vapors by squirrel cage  202 . Preferably, the sidewalls of reservoir  210  are dimensioned to correspond to the aperture though the lower surface of housing  203  to minimize leakage of the separated byproducts from blower unit  103 . 
     Removable shield-tray assembly  207  also prevents exposure to the spinning squirrel cage  202  and balances airflow into the blower unit. Removable shield-tray assembly  207  is also preferably constructed of metal, although other materials can also be used, such as plastics, which are resistant to heat, cooking byproducts, and cleaning products. In the embodiment of  FIGS. 2A and 2B , the axis of rotation of squirrel cage  202  is disposed generally parallel to the upper surface of reservoir  210  when shield-tray assembly  207  is fastened to housing  203 . 
     Specifically, the centrifugal action of spinning squirrel cage  202  separates grease from the heated vapors entering aperture  204  in blower housing  203  by liquefaction. The liquefied grease, and any other solid or liquid cooking byproducts separated from the incoming vapors, are cast to the parabolic internal walls (not shown) of housing  203  and then settle to reservoir  210  on removable shield-tray assembly  207 . Typically, a blower speed of approximately 1550 rpm maintains a suitable pressure to liquefy grease vapor from the received heated vapors. Centrifugal-action grease separation units, such as blower unit  103 , advantageously require less airflow than ventilation systems utilizing mesh or baffle filtration, and thus are very quiet during operation. A complete description of the operation and control of blower  103  is provided in co-assigned U.S. Pat. No. 6,142,142, incorporated herein by reference for all purposes. 
     As shown in  FIG. 2B , disposal of grease trapped within housing  203  of blower  103  only requires removing shield-tray assembly  207  and discarding the contents of receptacle  210 . In particular, power is first disconnected from blower unit  103  to prevent activation of the motor and squirrel cage  202 . Shield-tray assembly  207  is pulled away horizontally from housing  203  such that posts  209  on housing  203  disengage with the slots on tab  208  of shield-tray assembly  207 . Care is preferably taken to keep tray-assembly  207  level to prevent spillage of the contents of reservoir  210 . The accumulated grease and particulate matter within reservoir  210  is then appropriately discarded. Shield-tray assembly  207  may then be washed or cleaned with water and soap or detergent, either by and or with a dishwasher, and then reconnected to housing  203  via posts  209 . 
     Housing  203  may also be separated from rear section  201  by unlatching latches  206  and carefully pulling housing  203  past squirrel cage  202 . Housing  203  may then be washed or cleaned, for example with water and soap or detergent. As necessary, squirrel cage  202  may also be removed with a hex wrench and similarly cleaned. 
     The principles of the present invention are equally applicable for easily and efficiently removing and discarding grease and other cooking byproducts accumulated during the operation of other types of blower systems. For example, shield-tray assembly  207  can be advantageously used in connection with the low-profile blower-grease separator units disclosed in co-assigned U.S. Pat. No. 6,820,609, which is incorporated herein by reference for all purposes. In this case, the surface of reservoir  210  of shield-tray assembly  207  is disposed under and generally orthogonal to the axis of rotation of the squirrel cage. 
     In sum, the principles of the present invention are embodied in apparatus and methods that allow collected grease and particulate matter to be easily and quickly removed from the blower of a kitchen ventilation system. A removable shield-assembly simply slides away from the bottom of blower housing and the accumulated cooking byproducts within the shield-tray reservoir discarded. For a more thorough cleaning of the blower unit, the blower housing can also be removed using simple latches. 
     Although the invention has been described with reference to specific embodiments, these descriptions are not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed might be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. 
     It is therefore contemplated that the claims will cover any such modifications or embodiments that fall within the true scope of the invention.