OVERFLOW DETECTION SYSTEM FOR A GREASE TRAP

An overflow detection system for a grease trap or other receptacle is provided. The overflow detection system includes an overflow sensor. The overflow sensor can include a switch and a processor. The switch can include a float configured to float in a fluid in the receptacle, a surface that is separate from the float, and a resilient member coupled between the float and the surface. The switch can generate a signal in response to the float being within a predefined distance of (e.g., contacting) the surface. The processor can receive the signal from the switch and, in response, transmit a notification to a user device that is remote from the receptacle. The notification can indicate a high fluid level in the receptacle.

TECHNICAL FIELD

The present disclosure relates generally to overflow detection. More specifically, but not by way of limitation, this disclosure relates to an overflow detection system for a grease trap or other receptacle.

BACKGROUND

Grease traps are used in many restaurants and other stores to collect FOG (Fats, Oil, and Grease) from all the drains used within the store. Grease traps must be regularly cleaned to prevent them from overflowing. Because stores typically have passive grease traps which require manual cleaning (e.g., pumping) to remove the FOG that was trapped, there is no automatic removal or cleaning of the FOG. Therefore, a grease trap can overflow for any number of logistical or capacity/throughput driven reasons. Such overflows may be within or just outside of a store, and may occur above or below ground. If a grease trap overflows, normally the FOG is the first thing to overflow, because it floats to the top of the fluid mixture within the trap. Such FOG overflows are not only dangerous but can also damage equipment.

SUMMARY

On example of the present disclosure includes an overflow sensor comprising a switch. The switch can include a float configured to float in a fluid in a receptacle, a surface that is separate from the float, and a resilient member coupled between the float and the surface. The resilient member can be configured to normally hold the switch in an open position by spacing the float at a first distance from the surface. The switch can be configured to generate a signal in response to the float being within a second distance of the surface. The resilient member can be configured to allow the float to come within the second distance of the surface when the fluid in the receptacle exceeds a predefined fluid level. And the resilient member can be configured to prevent the float from coming within the second distance of the surface when the fluid in the receptacle does not exceed the predefined fluid level. The overflow sensor can also include a processor coupled to the switch. The overflow sensor can further include a memory including instructions that are executable by the processor for causing the processor to: receive the signal from the switch; and in response to receiving the signal, transmit a notification to a user device that is remote from the overflow sensor.

Another example of the present disclosure includes a receptacle comprising a fluid and an overflow sensor. The overflow sensor can include a switch. The switch can include a float configured to float in the fluid in the receptacle. The switch can also include a surface that is separate from the float. The switch can further include a resilient member coupled between the float and the surface. The switch can be configured to generate a signal in response to the float being within a predefined distance of the surface. The overflow sensor can also include a processor coupled to the switch. The overflow sensor can further include a memory including instructions that are executable by the processor for causing the processor to: receive the signal from the switch; and in response to receiving the signal, transmit a notification to a user device that is remote from the receptacle.

Yet another example of the present disclosure can include a method. The method can include detecting, by an overflow sensor positioned in a fluid in a receptacle, that a surface of the overflow sensor is within a predefined distance of a float of the overflow sensor. A resilient member can be coupled between the float and the surface of the overflow sensor. The method can include, based on detecting that the surface of the overflow sensor is within the predefined distance of the float, transmitting, by a processor of the overflow sensor, a notification to a user device that is remote from the receptacle.

DETAILED DESCRIPTION

Certain aspects and features of the present disclosure relate to an overflow sensor usable to detect a high fluid level in a receptacle such as a grease trap. A high fluid level can be a fluid level that is above a predefined threshold, such as 90% of the height of the receptacle. Upon detecting a high fluid level, the overflow sensor can wirelessly transmit a warning notification to a user about the high fluid level. This can allow the user to clean out the receptacle (e.g., to pump out fluid) to prevent overflow of the fluid.

The overflow sensor can be powered by a battery so that it lacks any external cables, such as power lines. And the overflow sensor may communicate wirelessly using low-frequency signals (e.g., signals below 100 Hz), so that the overflow sensor can be used in situations that would otherwise attenuate the wireless transmissions too much, such as if the receptacle is made of metal or concrete, or if the receptacle is buried underground. The overflow sensor may also be able to freely float in the fluid, so that it is not affixed to any surfaces within or outside of the receptacle. These features can allow the overflow sensor to be easily installed and used in a wider variety of applications.

More specifically, in some examples, the overflow sensor can include a floating body, which is also referred to herein as a float. The floating body can be configured to float at the surface of the fluid. The overflow sensor can also include a switch coupled to the floating body. For example, the switch can be coupled to the top of the floating body. The switch can include a moveable surface separated from the floating body by a resilient member, such as a spring. As the fluid level in the receptacle rises, the overflow sensor can rise with the fluid, given that it is free floating in the fluid. Eventually the fluid level can rise to a high enough level that the switch abuts a vertical limit (e.g., a top, shoulder, or beam of the receptacle) and compresses, thereby triggering the overflow sensor to transmit a warning notification to the user.

In other examples, the overflow sensor can include a body affixed to an underside of the top of the receptacle. The overflow sensor can also include a switch coupled to the body. For example, the switch can be coupled to the bottom of the body. The switch can have a float separated from the body by a resilient member. As the fluid level in the receptacle rises, eventually the fluid level can rise to a high enough level that the fluid pushes the float upwards to compress the switch, thereby triggering the overflow sensor to transmit a warning notification to the user.

FIG.1shows a block diagram of an example of an overflow sensor100according to some aspects of the present disclosure. The overflow sensor100includes a switch120positioned on the top of a float104. The float104can be configured to float in a fluid, such as water or a mixture of fat, oil, and grease. For example, the float104can be made of a plastic or rubber material having a suitable density to float to the top of such a mixture.

The switch120can include a movable surface102coupled to the float104by one or more resilient members106. The movable surface102can have any suitable shape and be formed from any suitable material, such as plastic or metal. The one or more resilient members106can be configured to expand and contract along the vertical axis of the overflow sensor100, as represented by the double-sided dashed arrow inFIG.1, so that the movable surface102can move toward and away from the float104. Examples of such resilient members106can include a spring (e.g., a coil spring or a leaf spring) and/or an elastic rod. The resilient members106can be configured to normally hold the switch120in an open position. For example, the resilient members106can exert an expansion force along the vertical axis, which can be perpendicular to a longitudinal length the movable surface102, to maintain the movable surface102at a default distance122from the float104during normal operating conditions (e.g., when the grease trap is not overfilled).

To use the overflow sensor100, the overflow sensor100can be disposed inside of a receptacle such as a grease trap. The overflow sensor100may not be affixed to any portion of the receptacle, but rather may be left floating in the fluid in the receptacle (or sitting on the bottom of the receptacle if the receptacle is empty). While the overflow sensor100is floating in the fluid during normal operating conditions, at least some of the overflow sensor100can sit in the fluid and at least some of the overflow sensor100can sit above and outside the fluid. For example, the float104can sit in the fluid and the movable surface102of the switch120can sit above and outside the fluid. As the amount of fluid in the receptacle increases, the overflow sensor100will rise given that it floats at the surface of the fluid. When the amount of fluid rises to a high enough level, the movable surface102may contact an upper interior surface (e.g., the top) of the receptacle, which prevents further upward movement of the movable surface102. If more fluid subsequently enters the receptacle, the continued upward movement of the float104can cause the one or more resilient members106to compress between the movable surface102and the float104. For example, the resilient members106can compress along the vertical axis (e.g., Y-axis) between the movable surface102and a surface124of the float104. When the resilient members106compresses far enough, the switch120can close. The overflow sensor100can detect the closure of the switch120and responsively output a notification128to a user. The notification128can indicate that the receptacle has a high fluid level that is approaching overflow.

In some examples, the switch120can include a contact sensor that includes one or more contacts108a-b,110a-bon opposing surfaces. For example, the switch120can include one or more contacts108a-bon an underside of the movable surface102and one or more contacts110a-bon the surface124of the float104. The contacts108a-b,110a-bcan be made of any suitable conductive material, such as metal. When the contacts108a-bon the movable surface102touch the contacts110a-bon the float104(e.g., during a compression of the resilient members106), the contact sensor can detect the contact and output a corresponding signal. Based on this signal, the overflow sensor100can transmit the notification128to the user.

Additionally or alternatively, the switch120can include a proximity sensor126configured to detect when the movable surface102is within a predefined distance of the float104(e.g., a predefined proximity of the surface124of the float104). Examples of the proximity sensor126can include an inductive proximity sensor, a capacitive proximity sensor, or an acoustic proximity sensor. In response to detecting that the movable surface102is within a predefined proximity (e.g., a threshold distance) of the float104, the proximity sensor126can output a corresponding signal. Based on this signal, the overflow sensor100can transmit the notification128to the user.

In some examples, the overflow sensor100can use the proximity sensor126to detect when the movable surface102is multiple predefined distances from the float104. In response to detecting that the movable surface102is at each of the predefined distances from the float104, the overflow sensor100can output a corresponding notification128. This can provide for a finer degree of granularity in the notification process. For example, multiple notifications of increasing priority or importance can be output to the user as the fluid level increases over time.

To provide the notifications128to the user, the overflow sensor100can include various electronic components. For example, the overflow sensor100can include a processor110communicatively coupled to a memory112and a wireless interface116. These electronic components may be disposed in the float104(which can serve as a body of the overflow sensor100), the movable surface102, or any combination thereof. If the processor110detects that the switch120is closed, for example based on a signal from a contact sensor of the switch120, the processor110can transmit one or more notifications128via the wireless interface116to one or more user devices of one or more users. Additionally or alternatively, if the processor110detects that the movable surface102is less than a threshold distance from the float104, for example based on a signal from a proximity sensor126, the processor110can transmit one or more notifications128via the wireless interface116to the one or more user devices. Some or all of the electronic components can be powered by a battery118, such as a lithium ion battery. The battery118and the other electronic components can be enclosed in one or more waterproof compartments of the overflow sensor100for protection.

The processor110can include one processor or multiple processors. Examples of the processor110can include a Field-Programmable Gate Array (FPGA), an application-specific integrated circuit (ASIC), or a microprocessor. The processor110can execute instructions114stored in the memory112to perform operations, such as any of the operations described herein. The instructions114may include processor-specific instructions generated by a compiler or an interpreter from code written in any suitable computer-programming language, such as C, C++, C#, Java, or Python.

The memory112can include one memory device or multiple memory devices. The memory112can be volatile or non-volatile (it can retain stored information when powered off). Examples of the memory112can include electrically erasable and programmable read-only memory (EEPROM), flash memory, or cache memory. At least some of the memory112includes a non-transitory computer-readable medium from which the processor110can read instructions114. A computer-readable medium can include electronic, optical, magnetic, or other storage devices capable of providing the processor110with the instructions114or other program code. Examples of a computer-readable mediums include magnetic disks, memory chips, ROM, random-access memory (RAM), an ASIC, a configured processor, and optical storage.

The wireless interface116can be configured to facilitate a wireless network connection. Examples of the wireless interface116can include IEEE 802.11, Bluetooth, or radio interfaces for accessing cellular telephone networks (e.g., transceiver/antenna for accessing a CDMA, GSM, UMTS, or other mobile communications network).

In some examples, the overflow sensor100can also include other components to facilitate its operation. For example, the overflow sensor100can include one or more guides configured to minimize lateral movement of the movable surface102along the X-axis and/or to help promote its vertical movement along the Y-axis. The overflow sensor100may also include one or more guides extending outwardly from the float104in a lateral direction to help maintain the float104at a desired location in the receptacle, such as substantially in the center of the receptacle. This can prevent the overflow sensor100from floating off to one side of the receptacle during use. Additionally, the overflow sensor100can include a weight at the bottom (e.g., at the bottom center of the float104) to help orient or maintain the overflow sensor100in an upright position during use.

Turning now toFIG.2,FIG.2shows a block diagram of an example of an overflow sensor100in a grease trap202according to some aspects of the present disclosure, though in other examples the overflow sensor100may be used with other types of receptacles and fluids. The grease trap202can be a receptacle through which wastewater containing fats, oil, and grease flows before entering a main drainage system, such as a sewer waste system. The grease trap202can be designed to intercept most fats, oils, and greases before they enter the main drainage system. The grease trap202can have an inlet pipe210and an outlet pipe212through which the wastewater can flow.

The overflow sensor100can be positioned in the grease trap202. For example, as shown, the whole overflow sensor100can be disposed inside of the grease trap202, so that there are no parts extending outside of the grease trap202. Additionally, the whole overflow sensor100can float freely on the fluid204in the grease trap202, because the overflow sensor100is not attached to any of the walls of the grease trap202or to any other component. For example, the overflow sensor100can freely move in the X-, Y-, and/or Z-directions within the grease trap202, depending on the height and motion of the fluid204.

In the example shown inFIG.2, the fluid204in the grease trap202is at a fluid level206that is sufficiently distant from an upper surface208(e.g., the top) of the grease trap202to prevent activation of the switch120. In particular, the fluid level206is low enough to prevent the movable surface102from abutting against the upper surface208and compressing the resilient members. But as the amount of fluid204increases, the float104will rise with the fluid level206. Eventually, the fluid level206may rise to the point where the movable surface102abuts against the upper surface208of the grease trap202. At that point, if the fluid level206continues to rise, the float104will begin to approach the movable surface102and compress the resilient members. The float104can continue to approach the movable surface102until the switch120is activated. The switch120may be considered activated when it is closed, as shown inFIG.3, or when the proximity sensor detects that the movable surface102is within a predefined distance of the float104. Either way, in response to activation of the switch120, the overflow sensor100can transmit a notification to warn a user that the fluid level206is close to overflowing.

Upon receiving the notification, the user may clean the grease trap202. For example, the user may pump at least some of the fluid out of the grease trap202. This may involve opening the top (e.g., upper surface208) of the grease trap202to remove the excess fluid. As the fluid level206decreases, the height of the float104in the grease trap202may decrease correspondingly, allowing the resilient members to decompress and expand. The fluid level206may decrease to the point where the movable surface102no longer abuts against the upper surface208of the grease trap202and the switch120is opened. Eventually, the resilient members have fully expanded back to their default state. At this point, the overflow sensor100may be considered fully reset for repeat use.

Turning now toFIG.4,FIG.4shows a block diagram of another example of an overflow sensor400in a grease trap202according to some aspects of the present disclosure, though in other examples the overflow sensor400may be used with other types of receptacles and fluids. The overflow sensor400can include a float402and a body404. The float402can be configured to float in a fluid204(e.g., water, oil, and/or grease) in the grease trap202. For example, the float402can be made of plastic or rubber having a suitable density to float to the top of such a mixture. The body404can be affixed to an upper surface208of the grease trap202, such as the underside of a top of the grease trap202. The top may be removable to service the grease trap202. The body404can affixed to the interior of the upper surface208using any suitable attachment means, such as screws, bolts, nails, glue, tape, or a hook-and-loop fastener. The overflow sensor400can generally include similar electronic components (e.g., a processor, memory, wireless interface, and/or battery) to the overflow sensor100described above. Those electronic components may be disposed in the float402, the body404, or any combination thereof. And as shown, the entire overflow sensor400can be disposed inside of the grease trap202, such that there are no parts extending outside of the grease trap202.

Much like the overflow sensor100ofFIG.1, the body404can be coupled to the float402by one or more resilient members106to form a switch120. The switch120can include a contact sensor with one or more contacts108a-b,110a-b, as described above. Additionally or alternatively, the switch120can include a proximity sensor, as described above. The resilient members106can be configured to normally hold the switch120in an open position. For example, the resilient members106can exert an expansion force along the vertical axis (e.g., Y-axis), which can be perpendicular to a horizontal axis (e.g., X-axis) of the float402, to maintain the float402at a default distance from the body404during normal operating conditions.

In some examples, the overflow sensor400can also include other components to facilitate its operation. For example, the overflow sensor400can include one or more guides configured to minimize lateral movement of the float402along the X-axis and/or to help promote its vertical movement along the Y-axis.

In the example shown inFIG.4, the grease trap202has a fluid level206that is sufficiently distant from the upper surface208to activate the switch120. In particular, the fluid level206is low enough to prevent the float402from compressing the resilient members106and closing the switch120. But as the fluid level206increases, the fluid204may contact the float402. At that point, if the fluid level206continues to rise, it may push the float402upwards towards the body404(e.g., the surface406of the body404) until the switch120is activated. The switch120may be considered activated when it is closed, as shown inFIG.5, or when the proximity sensor detects that the float402is within a predefined distance of the body404. Either way, in response to activation of the switch120, the overflow sensor400can transmit a notification to warn a user that the fluid level206is close to overflowing.

Upon receiving the notification, the user may clean the grease trap202. For example, the user may pump at least some of the fluid out of the grease trap202. This may involve opening the top (e.g., upper surface208) of the grease trap202to remove the excess fluid. As the fluid level206decreases, the height of the float402in the grease trap202may decrease correspondingly, allowing the resilient members to decompress and expand. The fluid level206may decrease to the point where the float402no longer abuts against the body404of the grease trap202and the switch120is opened. Eventually, the fluid level206may decrease to the point where the resilient members have fully expanded back to their default state. At this point, the overflow sensor400may be considered fully reset for repeat use.

Turning now toFIG.6,FIG.6shows a block diagram of an example of an overflow detection system600according to some aspects of the present disclosure. The overflow detection system600can include an overflow sensor602(e.g., overflow sensor100or overflow sensor400) in communication with a user device606via one or more networks604, such as a local area network or the Internet. Examples of the user device606can include a laptop computer, a desktop computer, a mobile phone such as a smartphone, a tablet, a wearable device such as a smart watch, or an e-reader. The overflow sensor602can detect a high fluid level in a grease trap202or other receptacle. The overflow sensor602may detect the high fluid level based on a signal from a switch120or based on a signal from a proximity sensor, as discussed above. In response to detecting the high fluid level, the overflow sensor602can transmit a notification612to the user device606. The notification612can be wirelessly transmitted to the user device606via the one or more networks604. The user device606can receive the notification612and responsively output an audio, visual, haptic, and/or other alert610to a user614. This can notify the user614of the high fluid level, for example so that the user614can perform a corrective action like cleaning out the receptacle.

Turning now toFIG.7,FIG.7shows a flowchart of an example of a process implemented by an overflow detection system according to some aspects of the present disclosure. The operations ofFIG.7are described below with reference to the components ofFIGS.1-6above.

In block702, an overflow sensor602in a receptacle such as a grease trap202detects that a surface of the overflow sensor602is within a predefined distance of (e.g., contacting) a float of the overflow sensor602. A resilient member106can be disposed between the surface and the float (e.g., the resilient member106can couple the surface to the float). For instance, in the example shown inFIGS.1-3, the overflow sensor602can detect that the movable surface102is within a predefined distance of the float104. In the example shown inFIGS.4-5, the overflow sensor602can detect that the surface406(of the body404of the overflow sensor602) is within a predefined distance of the float402.

In block704, based on detecting that the surface of the overflow sensor602is within the predefined distance of the float, the overflow sensor602transmits a notification612to a user device606that is remote from the receptacle, the notification612being configured to indicate a high fluid level in the receptacle.