Patent Application
20070194159
The present disclosure relates generally to food waste disposers.
Food waste disposers are used to comminute food scraps into particles small enough to safely pass through household drain plumbing. A conventional disposer includes grinding mechanism that is driven by a motor. The grinding mechanism is situated in a housing that forms an inlet connected to a sink drain opening for receiving food waste and water. The grind mechanism typically includes a rotating shredder plate with lugs and a stationary grind ring attached to the inside of the housing.
In operation of the disposer, a user puts the food waste into the inlet, and activates the motor. The motor turns the rotating shredder plate and the lugs force the food waste against the grind ring where it is broken down into small pieces. In a typical kitchen application, the kitchen faucet is opened so that water runs into the disposer inlet to rinse and carry the food waste through the grind mechanism during the grinding operation. Once the particles are small enough to pass out of the grinding mechanism, they are flushed out into the household plumbing along with the water running into the grinding mechanism.
Insufficient water flow through the disposer during the grinding process can result in less than optimal performance. Waste particles can adhere to the surfaces of the grind mechanism components and to the interior of the grind section housing. Inadequate rinsing can cause food build up and odor to occur. This can result in odors and even reduced grind performance, and can also result in blockages of downstream plumbing. Further, excessive water flow through the disposer is wasteful.
The present application addresses shortcomings associated with the prior art.
A food waste disposer system includes a housing with a grinding mechanism situated in the housing for reducing food waste. A motor drives the grinding mechanism. An outlet receives the reduced food waste from the grinding mechanism to discharge the food waste from the disposer housing. A water flow detector is situated to sense water flow through the housing.
In exemplary embodiments, the water flow detector includes a processor that determines the water flow rate through the outlet. In accordance with further aspects of the disclosure, the water flow detector includes a sense capacitor, and the processor measures the capacitance of the sense capacitor to determine water flow. Various methods of calculating the capacitance, and thus the water flow rate, are disclosed herein. For example, the rate at which the sense capacitor charges and/or discharges is determined. A larger capacitance will result in correspondingly longer charge and discharge rates. In still further exemplary embodiments, the frequency of an oscillator connected to the sense capacitor is monitored to determine capacitance.
In certain implementations, the water flow detector is connected to the disposer's drain pipe, which receives water from the disposer outlet. Two conductive plates are situated opposite one another on the drain pipe to form the sense capacitor, wherein the capacitance varies in response to water flow through the drain pipe, and thus between the plates of the sense capacitor. To provide optimum operation of the disposer and conserve water, the disposer motor is controlled in response to the sensed water flow through the disposer. For example, the disposer's motor is not turned on until adequate water flow is sensed, and the motor is turned off if excessive water flow is detected.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.
Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
A water flow detector 200 senses water flow through the disposer 100. In the exemplary system 100 illustrated in
In general, a capacitor with water between the plates has more capacitance than a capacitor with air between the plates, assuming the distance between the plates remains constant. With greater water flow, more space between the capacitor's plates is filled with water rather than air. Measuring the capacitance gives an indication of the amount of water flowing through the drain pipe 128, and thus the disposer 100.
There are a variety of factors that can change the capacitance of the sense capacitor 214 in addition to the amount of water flow. If grease or minerals in the drain pipe 128 change the capacitance readings, the processor 220 can be programmed to recalibrate to compensate for such other factors. If electrical noise (such as from the motor 106) causes erroneous readings, determining the capacitance several times and then averaging the result may compensate. In exemplary embodiments, capacitance is measured and updated twice per second.
The processor 200 is further connected to the motor 106 or a motor controller in some embodiments, allowing control of the disposer motor 106 in response to the measured water flow. For example, the processor 220 signals the motor 106 to turn on only if the water flow exceeds a predetermined amount, such as 1.5 GPM. Further, to conserve water, the processor 220 can signal the motor to turn off if excessive water flow is determined, such as flow greater than 2.2 GPM. In still further embodiments, water flow must be detected for a predetermined time period (three seconds, for example) before the processor 220 signals the motor 106 to start. An override is provided in situations where a user wishes to operate the disposer 100 independent of the water flow measurements.
The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the claims below.
