Patent Application
20160198926
The subject matter of the present disclosure relates generally to dishwasher appliances, and more particularly to fluid circulation systems with improved filtration in dishwasher appliances.
Dishwasher appliances generally include a tub that defines a wash compartment. Rack assemblies can be mounted within the wash chamber of the tub for receipt of articles for washing. Spray assemblies within the wash chamber can apply or direct wash fluid towards articles disposed within the rack assemblies in order to clean such articles. Multiple spray assemblies can be provided including e.g., a lower spray arm assembly mounted to the tub at a bottom of the wash chamber, a mid-level spray arm assembly mounted to one of the rack assemblies, and/or an upper spray assembly mounted to the tub at a top of the wash chamber. Other configurations may be used as well.
Dishwasher appliances further typically include a fluid circulation system which is in fluid communication with the spray assemblies for circulating fluid to the spray assemblies. The fluid circulation system generally receives fluid from the wash chamber, filters soil from the fluid, and flows the filtered fluid to the spray assemblies. Additionally, unfiltered fluid can be flowed to a drain as required.
Currently known fluid circulation systems utilize a large, flat, coarse filter and a cylindrical fine filter to filter soil. Each of these filters typically has constant filter hole, or perforation, sizes which are vulnerable to clogging during operation of the dishwasher appliance. Further, the constant filter hole sizes cannot respond to differences in soil conditions during operation.
Accordingly, improved fluid circulation systems for dishwasher appliances are desired. In particular, fluid circulation systems which provide improved fluid filtering would be advantageous.
Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
In accordance with one embodiment, a fluid circulation system for a dishwasher appliance is provided. The dishwasher appliance includes a tub that defines a wash chamber. The fluid circulation system includes a sump for receiving fluid from the wash chamber, the sump comprising a chamber having a sidewall and a base wall. The fluid circulation system further includes a pump, the pump including an impeller disposed within the chamber. The fluid circulation system further includes a filter disposed within the chamber and surrounding the impeller, the filter including a sidewall, the sidewall defining a plurality of perforations extending therethrough. A volume within the filter is greater than a volume between the sidewall of the chamber and the sidewall of the filter for a given height from the base wall.
In accordance with another embodiment, a fluid circulation system for a dishwasher appliance is provided. The dishwasher appliance includes a tub that defines a wash chamber. The fluid circulation system includes a sump for receiving fluid from the wash chamber, the sump comprising a chamber having a sidewall and a base wall. The fluid circulation system further includes a pump, the pump including an impeller disposed within the chamber. The fluid circulation system further includes a filter disposed within the chamber and surrounding the impeller, the filter including a sidewall, the sidewall defining a plurality of perforations extending therethrough. Volumes of the plurality of perforations increase along a height from the base wall.
These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
A full and enabling disclosure of the present invention including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:
Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
As used herein, the term “article” may refer to, but need not be limited to, dishes, pots, pans, silverware, and other cooking utensils and items that can be cleaned in a dishwashing appliance. The term “wash cycle” is intended to refer to one or more periods of time during the cleaning process where a dishwashing appliance operates while containing articles to be washed and uses a detergent and water, preferably with agitation, to e.g., remove soil particles including food and other undesirable elements from the articles. The term “rinse cycle” is intended to refer to one or more periods of time during the cleaning process in which the dishwashing appliance operates to remove residual soil, detergents, and other undesirable elements that were retained by the articles after completion of the wash cycle. The term “drying cycle” is intended to refer to one or more periods of time in which the dishwashing appliance is operated to dry the articles by removing fluids from the wash chamber. The term “fluid” refers to a liquid used for washing and/or rinsing the articles and is typically made up of water that may include additives such as e.g., detergent or other treatments.
Upper and lower guide rails 124, 126 are mounted on tub side walls 128 and accommodate roller-equipped rack assemblies 130 and 132. Each of the rack assemblies 130, 132 is fabricated into lattice structures including a plurality of elongated members 134 (for clarity of illustration, not all elongated members making up assemblies 130 and 132 are shown in
The dishwasher appliance 100 further includes a lower spray-arm assembly 144 that is rotatably mounted within a lower region 146 of the wash chamber 106 and above a bottom wall 142 of the tub 104 so as to rotate in relatively close proximity to rack assembly 132. A mid-level spray-arm assembly 148 is located in an upper region of the wash chamber 106 and may be located in close proximity to upper rack 130. Additionally, an upper spray assembly 150 may be located above the upper rack 130.
Each spray arm-assembly 144 may include a spray arm and a conduit in fluid communication with the spray arm, for providing a fluid flow to the spray arm. For example, mid-level spray-arm assembly 148 may include a spray arm 160 and a conduit 162. Lower spray-arm assembly 144 may include a spray arm 164 and a conduit 166. Additionally, upper spray assembly 150 may include a spray head 170 and a conduit 172 in fluid communication with the spray head 170.
The lower and mid-level spray-arm assemblies 144, 148 and the upper spray assembly 150 are part of a fluid circulation system 152 for circulating fluid in the dishwasher appliance 100. The fluid circulation system 152 also includes various components for receiving fluid from the wash chamber 106, filtering the fluid, and flowing the fluid to the various spray assemblies such as the lower and mid-level spray-arm assemblies 144, 148 and the upper spray assembly 150. As discussed herein such components can be generally positioned within a machinery compartment 140 below the bottom wall 142 and in communication with the wash chamber 106.
The dishwasher appliance 100 is further equipped with a controller 137 to regulate operation of the dishwasher appliance 100. The controller may include one or more memory devices and one or more microprocessors, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with a cleaning cycle. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor.
The controller 137 may be positioned in a variety of locations throughout dishwasher appliance 100. In the illustrated embodiment, the controller 137 may be located within a control panel area 121 of door 120 as shown in
It should be appreciated that the invention is not limited to any particular style, model, or configuration of dishwasher. The exemplary embodiment depicted in
Referring now to
Sump 200 may include, for example, a chamber 202 which receives the fluid from the wash chamber 106. Sump 200 may additionally include a receptacle 204 which may, for example, receive the fluid from the wash chamber 106 and flow this fluid to the chamber 202. Receptacle 204 and chamber 202 may be integral portions of a single sump 200 component, or may be separate portions that are connected to form the sump 200. The receptacle 204 may thus be an upper receptacle positioned above the lower chamber 202 along the vertical direction V. Receptacle may have a generally conical or funnel shape which directs the fluid flow towards and into the chamber 202, or may have any other suitable shape.
As illustrated, chamber 202 may include a sidewall 206 and a base wall 208. The sidewall 206 may extend from the base wall 208. In some embodiments, the sidewall 206 may have a generally circular cross-sectional shape, as illustrated in
System 152 may further include a pump 210. Pump 210 may include an impeller 212 which is disposed within the chamber 202. Pump 210 may further include a motor 214 and a shaft 216 which connects the motor 214 and impeller 212. As illustrated, the shaft 216 may extend through the base wall 208, and the motor 214 may be external to the chamber 202. Alternatively, the motor 214 may be disposed within the chamber 202, and may for example be hermetically sealed to prevent damage thereto from fluids within the chamber 202. Impeller 212 may spin within the chamber 202 when activated by the motor 214 to influence the flow of fluid within the chamber 202. Pump 210 may further include a diffuser 218. Diffuser 218 may receive fluid influenced by the impeller 212. Fluid may thus flow through the diffuser 218 and exit the pump 210 through the diffuser 218.
System 152 may further include an outlet conduit 220. The outlet conduit 220 flows fluid from the sump 200, such as from the chamber 202 thereof, to the wash chamber 106. For example, outlet conduit 220 may be connected to and in fluid communication with the various spray assemblies, such as the lower and mid-level spray-arm assemblies 144, 148 and the upper spray assembly 150, such that fluid flowed into the outlet conduit 220 can flow to these spray assemblies. Valves (not shown) disposed within the outlet conduit 220 or other conduits in the system 152 may selectively direct the flow of fluid from the outlet conduit 220 as required. Outlet conduit 220 may further be connected to and in fluid communication with the diffuser 218. Accordingly, fluid drawn into the diffuser 218 from the impeller 212 may flow from the diffuser 218 into the outlet conduit 220 towards, for example, the spray assemblies, drain assembly, etc.
As illustrated in
As illustrated, a filter 250 in accordance with the present disclosure may include a sidewall 252. Filter 250 may further include a top wall 254, through which the outlet conduit 220 extends. Still further, filter 250 may include a base wall (not shown) that contacts the base wall 208 of the chamber 202, or the sidewall 252 may contact the base wall 208. The sidewall 252 may extend from the top wall 254 or between the top wall 254 and bottom wall. In some embodiments, the sidewall 252 may have a generally circular cross-sectional shape, as illustrated in
As further illustrated, the sidewall 252, as well as the top wall 254 and bottom wall, may define a plurality of perforations 256 extending therethrough. The perforations 256 may, as discussed herein, be sized and shaped to allow fluid flow therethrough, while preventing the flow of soil therethrough, thus filtering the fluid as it flows into the filter 250 through the walls thereof. Each perforation 256 may have any suitable shape, such as a generally circular cross-sectional shape, a generally rectangular cross-sectional shape, or other suitable polygonal cross-sectional shape. In the embodiments shown, the perforations are assumed to have circular cross-sectional shapes and thus be cylindrical.
In some exemplary embodiments, as shown, a volume within the filter 250 is greater than a volume between the sidewall 206 of the chamber 202 and the sidewall 252 of the filter 250 for a given height 260 from the base wall 208. In other words, at any given height 260 from the base wall 208 (through which the sidewall 206 and sidewall 252 extend), the volume within the filter 250 is greater than the volume without the filter 250 (between the filter sidewall 252 and chamber sidewall 206). Advantageously, such arrangement allows the filter 250 to respond to differences in soil conditions in order to reducing clogging thereof. For example,
In some embodiments, as illustrated in
In other embodiments, as illustrated in
In additional or alternative embodiments, the perforations 256 may advantageously be configured to facilitate improved filtration and reduced clogging. For example, and referring to
In some embodiments, as illustrated in
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
