Dual loop fuel filtration system with controller

A filtration system is provided. The system provides a first filtration loop that provides one or more passes through a first filter using a first pump and a second filtration loop that provides one or more passes through a second filter using a second pump. The combination of a first pump and a second pump, each with a filter and each running independently of engine speed, provides an effective means of cleaning fuel.

TECHNICAL FIELD

The present disclosure relates generally to a filtration system, and, more particularly, to a filtration system in which a first pump located in a first filtration loop and a second pump located in a second filtration loop may run independently of engine speed, thereby recirculating and filtering an amount of fuel much greater than the amount of fuel being consumed by the engine.

BACKGROUND

Modern engine fuel systems require high operating pressures to produce acceptable performance and emissions. The high pressures require small clearances between parts to minimize leakage and other factors that can adversely impact performance. Debris in fuel can be of such a size that it can damage the internal parts of the fuel system, reducing performance of the fuel system and engine.

Fuel filtration systems are known that remove debris from fuel using a recirculation filtration loop. For example, U.S. Patent Publication No. 2014/0224215 discloses a system for removing debris from fuel using a single recirculation fuel loop. The system includes a pump configured to receive a flow of fuel from a fuel tank, a first filter and a recirculation loop configured to recirculate at least a portion of the fuel through the first filter. At least one additional filter may be positioned downstream of the system. While effective for its intended purposes, improvements in fuel filtration systems continue to be sought.

The present disclosure presents a system for removing debris from fluids such as fuel. The system uses multiple recirculating loops to filter an amount of fuel many more times that being consumed by an engine. While a number of exemplary configurations are described herein, it should be appreciated that the examples are not a limitation on the scope of this disclosure or of the attached claims except to the extent expressly noted.

SUMMARY

According to an aspect of the disclosure, a filtration system for use with an engine configured to operate at a range of speeds comprises a first filtration loop and a second filtration loop. The first filtration loop comprises a first filter having a first filter inlet port and a first filter outlet port, a first motor and a first pump operatively coupled to the first motor. An outlet port of the first pump is fluidly coupled to the first filter inlet port via a first filter inlet conduit. An inlet port of the first pump is fluidly coupled to the first filter outlet port via a first filter outlet conduit and a first recirculation conduit. The second filtration loop comprises a second filter having a second filter inlet port and a second filter outlet port and a second pump. An inlet port of the second pump is fluidly coupled to the first filter outlet port via the first filter outlet conduit and an interloop conduit. An outlet port of the second pump is fluidly coupled to the second filter inlet port via a second filter inlet conduit. The inlet port of the second pump is fluidly coupled to the second filter outlet port via a second filter outlet conduit, a second recirculation conduit fluidly coupled to the second filter outlet conduit upstream of the engine and a portion of the interloop conduit. A first flow meter may be fluidly coupled to the interloop conduit for measuring flow through the interloop conduit. An optional second flow meter may be located downstream of the engine for measuring the flow of fuel exiting the engine. A controller may be operatively coupled to the first flow meter, the second flow meter and the first motor. The controller may be configured to operate the first motor, and thus the first pump and the second pump, whereby fuel is distributed between the first filtration loop and the second filtration loop.

According to another aspect of the disclosure, a filtration system for use with an engine configured to operate at a range of speeds comprises a first filtration loop and a second filtration loop, the first filtration loop comprising a first filter having a first filter inlet port and a first filter outlet port, a first motor, and a first pump operatively coupled to the first motor, an outlet port of the first pump being fluidly coupled to the first filter inlet port via a first filter inlet conduit, an inlet port of the first pump being fluidly coupled to the first filter outlet port via a first filter outlet conduit and a first recirculation conduit. The second filtration loop comprises a second filter having a second filter inlet port and a second pump. An inlet port of the second pump may be fluidly coupled to the first filter outlet port via the first filter outlet conduit and an interloop conduit. An outlet port of the second pump may be fluidly coupled to the second filter inlet port via a second filter inlet conduit. The inlet port of the second pump may be fluidly coupled to the outlet port of the second filter via the second filter outlet conduit, an alternative second recirculation conduit fluidly coupled to an engine fuel outlet and a portion of the interloop conduit. A first flow meter may be fluidly coupled to the interloop conduit for measuring flow through the interloop conduit and a second flow meter may be located downstream of the engine for measuring the flow of fuel exiting the engine. A controller may be operatively coupled to the first flow meter, the second flow meter and the first motor. The controller may be configured to operate the first motor, and thus the first pump and the second pump, whereby fuel is distributed between the first filtration loop and the second filtration loop.

According to another aspect of the disclosure, a machine comprises an engine configured to operate at a range of speeds, a fuel tank and a filtration system comprising a first filtration loop and a second filtration loop. The first filtration loop may comprise a first filter having a first filter inlet port and a first filter outlet port, a first motor and a first pump operatively coupled to the first motor. An outlet port of the first pump may be fluidly coupled to the first filter inlet port via a first filter inlet conduit. An inlet port of the first pump may be fluidly coupled to the first filter outlet port via a first filter outlet conduit and a first recirculation conduit. The second filtration loop may comprise a second filter having a second filter inlet port and a second pump. An inlet port of the second pump may be fluidly coupled to the first filter outlet port via the first filter outlet conduit and an interloop conduit. An outlet port of the second pump may be fluidly coupled to the second filter inlet port via a second filter inlet conduit. The inlet port of the second pump may be fluidly coupled to the second filter outlet port via a second filter outlet conduit, a second recirculation conduit fluidly coupled to the second filter outlet conduit upstream of the engine and a portion of the interloop conduit. A first flow meter may be fluidly coupled to the interloop conduit for measuring flow through the interloop conduit. A second flow meter may be located downstream of the engine for measuring the flow of fuel exiting the engine. A controller may be operatively coupled to the first flow meter, the second flow meter and the first motor. The controller may be configured to operate the first motor, and thus the first pump and the second pump, whereby fuel is distributed between the first filtration loop and the second filtration loop.

Other aspects and features of the disclosed systems and methods will be appreciated from reading the attached detailed description in conjunction with the included drawing figures. Moreover, selected aspects and features of one example embodiment may be combined with various selected aspects and features of other example embodiments.

It is to be noted that the appended drawings illustrate only typical embodiments and are therefore not to be considered limiting with respect to the scope of the disclosure or claims. Rather, the concepts of the present disclosure may apply within other equally effective embodiments. Moreover, the drawings are not necessarily to scale, emphasis generally being placed upon illustrating the principles of certain embodiments.

DETAILED DESCRIPTION

An exemplary embodiment of a machine10according to the present disclosure is shown inFIG. 1. The machine10may be a mining truck, as shown, or may be any off-highway or on-highway vehicle using a fuel-powered engine, as described herein. The machine10generally includes a machine frame12for supporting, among other systems and components, a filtration system which will be discussed in greater detail in connection withFIGS. 2 and 3.

The machine10may also include a plurality of ground-engaging elements14, in this case wheels. As should be appreciated by one of ordinary skill in the art, an engine may provide propulsion power for the ground-engaging elements14and may power a variety of other machine systems, including various mechanical, electrical, and hydraulic systems and/or components. The machine10may also include an operator control station16including a variety of operator controls and displays useful for operating the machine10and/or a dump body18which may be pivotal relative to the machine frame12.

First Embodiment

FIG. 2illustrates an exemplary configuration of a filtration system120that may be used with the machine10ofFIG. 1or any suitable machine, including but not limited to mining trucks, earth moving equipment, on and off highway trucks, construction machines, stationary engines and marine vessels. The direction of fuel flow is indicated by arrowheads in the figures.

In the configuration depicted inFIG. 2, fuel is pumped across at least two separate filters. Fuel passing through a first filter144may be split into a first stream that is recirculated back through the first filter144via a first filtration loop140and into a second stream that passes through a second filter174. Fuel passing through the second filter174may be split into a fuel stream that is recirculated back through the second filter174via a second filtration loop170and into a fuel stream that may enter the engine122. The amount of fuel passing through each of the first and second filters144,174may be a function of the design flow rates of the first and second pumps142,172, with the first pump142having a higher design flow rate than the second pump172. As a result, a volume of fuel entering the first filtration loop140will likely flow through the first filter144multiple times before advancing to the second filtration loop170. And a volume of fuel entering the second filtration loop170will likely flow through the second filter174multiple times before advancing to the engine122, thereby improving the quality of the fuel with each successive pass through the first filter144and the second filter174.

The first filtration loop140may include a first pump142, a first filter144and a first motor112. An inlet port146to the first pump142may be fluidly coupled to the fuel tank124via a first conduit148. An outlet port150from the first pump142may be fluidly coupled to an inlet port152of the first filter144via a first filter inlet conduit154. An outlet port160of the first filter144may be fluidly coupled to a first node158by a first filter outlet conduit156.

The first node158may be fluidly coupled to the first pump inlet port146via a first recirculation conduit162, the fuel tank124and the first conduit148. Thus, the first filter inlet conduit154, the first filter outlet conduit156, the first recirculation conduit162, the fuel tank124and the first conduit148may form a first filtration loop140about the first pump142, which includes the first filter144.

Alternatively, the first node158may be fluidly coupled to the first pump inlet port146via a portion of the first recirculation conduit162and an alternative first recirculation conduit164that bypasses the fuel tank124. Thus, the first filtration loop140may bypass the fuel tank124. The alternative fuel recirculation conduit164may be fluidly coupled to the first recirculation conduit162at a second node166between the first filter outlet port160and the fuel tank124. Thus, in this alternative configuration, the first filter inlet conduit154, the first filter outlet conduit156, a portion of the first recirculation conduit162between the first node158and the second node166and the alternative first recirculation conduit164may form the first filtration loop140about the first pump142.

The second filtration loop170may include a second pump172and a second filter174. An inlet port176to the second pump172may be fluidly coupled to the first node158via an interloop conduit178. An outlet port180from the second pump172is fluidly coupled to an inlet port182of the second filter174via a second filter inlet conduit184. A second filter outlet conduit190may be fluidly coupled to the second filter outlet port186and to a third node188located upstream of the engine122. A second recirculation conduit192is fluidly coupled to the third node188and to a fourth node194located in the interloop conduit178. The fourth node194may be located between the first node158and the second pump inlet port176. Thus, the second filter outlet port186is fluidly coupled to the second pump inlet port176via the second filter outlet conduit190, the second recirculation conduit192and a portion179of the interloop conduit178downstream of the fourth node194. Accordingly, the second filter inlet conduit184, the second filter outlet conduit190, the second recirculation conduit192and the portion179of the interloop conduit178between the fourth node194and the second pump inlet port176form the second filtration loop170about the second pump172, which includes the second filter174.

As noted above, the second filtration loop170fluidly connects the second filter outlet port186to an inlet port176of the second pump172, bypassing the engine122, and thus is configured to carry a portion of the fuel exiting the second filter174back to the second pump172and back through the second filter174. A first check valve200may be positioned in the second filtration loop170and, more particularly, in the second recirculation conduit192.

The engine122may be an internal combustion engine such as a diesel engine and may comprise injectors123. The engine122, the fuel tank124, the first filtration loop140and the second filtration loop170are fluidly coupled such that the first and second filtration loops140,170may be provided downstream of the fuel tank124and upstream of the engine122.

An excess of fuel may be sent to the engine122to provide injector cooling and assure that enough fuel is getting to the injectors123to provide the desired power. The injectors123supply fuel to the engine122to produce power, while excess fuel passes around the injectors123and may be used for cooling the injectors123and/or for cooling other components such as high pressure pumps.

The first pump142may be a relatively lower pressure, higher flow pump and may be an impeller pump or another type of pump, such as a roller pump, gear pump or gerotor pump. The first pump142is driven by (and operatively coupled to) the first motor112and may be fluidly connected to the fuel tank124in order to receive the fuel stored in the fuel tank124.

The second pump172may be a relatively higher pressure, lower flow pump and may be a gerotor pump or any suitable pump. The second pump172is configured to pressurize the fuel flowing towards the engine122. The second pump172may be powered by the same first motor112as the first pump142or a different (second) motor113. If powered by the same first motor112, the first pump142may be physically configured to produce a larger flow rate that the second pump172. Alternatively, the first motor112may include gearing such that the second pump172may operate at a different speed than the first pump142. Alternatively, the pumps themselves, or the mechanical connection between the pumps, may incorporate gearing configurations that allow the pumps to operate at different speeds. Both first and second motors112,113may run independently of engine speed and may have power demands that the controller110can measure and compare with pre-programmed values to determine conditions in the filtration system120, such as fuel filter loading and pump wear. If the measured versus expected values exceed certain ranges, then the controller110can make appropriate notifications to the machine operator.

The interloop conduit178extends from the first node158to the second pump inlet port176and fluidly connects the first filtration loop140downstream of the first filter144to the second pump172. The second pump172draws fuel through the interloop conduit178from the first filtration loop140. The amount of fuel drawn from the first filtration loop140equals whatever fuel the engine122requires, that is whatever the engine122is burning, plus whatever fuel is needed for auxiliary functions, such as injector cooling and emissions control.

A first flow meter196may be fluidly coupled to the interloop conduit178and may measure fuel flow through the interloop conduit178upstream of the fourth node194. The first flow meter196may be operably coupled to the controller110and may transmit a signal to the controller110regarding flow rate.

An optional second flow meter198located downstream of the engine fuel outlet199measures fuel flow exiting the engine122and may function to assure that a sufficient amount of fuel is passing through the engine122to provide good injector cooling and to provide for combustion and auxiliary functions (such as emission control). The second flow meter198may be operably coupled to the controller110and may transmit a signal to the controller110regarding flow rate.

The controller110may be operatively coupled, either directly or indirectly through another component, to the first flow meter196, the second flow meter198and to the first and second motor(s)112,113driving the first pump142and the second pump172. The first and second motor(s)112,113may be variable speed motors and the controller110may be configured to vary the speed of the first and second motor(s)112,113based on various factors, including the speed and fuel consumption of the engine122. The controller110may monitor the fuel consumption of the engine122and then adjust the first and second motor(s)112,113to properly distribute the fuel between the first filtration loop140and the second filtration loop170independently of engine speed.

The controller110may be any controller or processor suitable for effectively controlling the dual loop filtration system120. The controller110may include electronics, preprogrammed logic circuits, data processing circuits, memory, software, firmware, input/output processing circuits, combinations thereof, and any other controller components known in the art. The controller110may be modular or unitary and may be fastened to the machine10in any suitable manner or location. The controller110may receive power from a power source (not shown) via a power conduit or the like.

Auxiliary units may include an emissions module128and a heat exchanger134. The emissions module128may run only when necessary, but when it does, it requires fuel. Within one type of exemplary emissions module128, fuel is sprayed on an igniter and fuel is burned, generating heat that is sent down an exhaust pipe (not shown) to burn excess particulates in a diesel particulate filter located in the exhaust line. The heat exchanger134may be used to pre-heat the fuel entering the engine122while cooling the fuel that flows back to the fuel tank124via a return conduit136. The first filtration loop140and the second filtration loop170provide the fuel required by the emissions module128and the heat exchanger134.

FIG. 4illustrates a method300of fuel filtration using the dual loop filtration system120ofFIG. 2. The method300may comprise the following steps:

Step302: Fuel from the fuel tank124is drawn into the first pump142and then through the first filter144located on the pressure side of the first pump142. A portion of the fuel coming off the first filter144is recirculated through the first filter144, while the remaining portion flows into the second filtration loop170via the interloop conduit178. In the second filtration loop170the fuel flows through the second pump172and through the second filter174and then is split so that a portion flows back through the second filter174via a second recirculation conduit192and the remaining portion flows to the engine122.

Step304: The controller110adjusts the speed of the first motor112and, if present, the second motor113, to distribute the fuel between the first filtration loop140and the second filtration loop170.

Step306: Based on input from the controller110, at least a portion of the fuel exiting the first filter144is recirculated back to the first filter144via the first recirculation conduit162or the alternative first recirculation conduit164.

Step308: The fuel flowing out of the first filter144and not recirculated through first filter144is drawn into the second pump172via the interloop conduit178and then filtered through the second filter174.

Step310: Some fuel flowing through the second filter174may be recirculated back through the second filter174.

Step312: The fuel flowing out of the second filter174and not recirculated back though the second filter174flows to the engine122.

Step314: Some fuel flowing through the engine122may avoid combustion and exit the engine122. All or a portion of the fuel exiting the engine122may flow back to the fuel tank124via return conduit136.

The second pump172sends fuel to the engine122and auxiliary units, and the first filtration loop140recirculates whatever fuel the engine122and any auxiliary units (such as the emissions module128) do not consume.

Second Embodiment

FIG. 3illustrates an exemplary embodiment of an alternative filtration system220. As with the previous embodiment, fuel is pumped across a first pump142via a first filtration loop140. In this embodiment, fuel is pumped across a second pump172via an alternative second filtration loop270. Also like the previous embodiment, the first filtration loop140allows a flow of fuel from the first filter144to be recirculated back through the first filter144. However, in this embodiment, the second recirculation conduit192ofFIG. 2is eliminated and an alternative second recirculation conduit202added. The alternative second recirculation conduit202fluidly connects the fuel outlet199of the engine122to a fifth node204downstream of the engine fuel outlet199and then to the fourth node194located in the interloop conduit178upstream of the second pump172.

Still referring toFIG. 3, the alternative second filtration loop270may include a second pump172and a second filter174. An inlet port176to the second pump172may be fluidly coupled to the fourth node194node via a portion179of the interloop conduit178. The second pump outlet port180is fluidly coupled to the second filter inlet port182via the second filter inlet conduit184. The second filter outlet port186is fluidly coupled to the engine122via a second filter outlet conduit190. The engine fuel outlet199is fluidly coupled to the second pump inlet port176via the alternative second recirculation conduit202and the portion179of the interloop conduit178between the fourth node194and the second pump inlet port176. Accordingly, the second filter inlet conduit184, the second filter outlet conduit190, the alternative second recirculation conduit202and the portion179of the interloop conduit178between the fourth node194and the second pump inlet port176form the alternative second filtration loop270about the second pump172, which includes the second filter174.

As noted above, the alternative second recirculation conduit202fluidly connects the engine fuel outlet199to the fourth node194and thus to an inlet port176of the second pump172. A second check valve206may be positioned in the alternative second filtration loop270and, more specifically, in the alternative second recirculation conduit202.

As in the previous embodiment, the interloop conduit178fluidly connects the first filtration loop140downstream of the first filter144to the second pump172. The second pump172draws fuel through the interloop conduit178from the first filtration loop140.

As in the first embodiment, the first flow meter196measures fuel flow through the interloop conduit178, which is the only fluid link between the two filtration loops140,170. The first flow meter196may be operably connected to the controller110.

Also as in the first embodiment, a second flow meter198located at or near the engine fuel outlet199may function to assure that a sufficient amount of fuel is passing through the engine122to provide sufficient fuel for engine consumption, injector cooling, and also for auxiliary functions (such as emission control).

The controller110may be communicably coupled to the first flow meter196, the second flow meter198and to the first and second motor(s)112,113driving the first pump142and the second pump172. The controller110may monitor the fuel consumption of the engine122and then adjust the first and second motor(s)112,113to properly distribute the fuel between the first filtration loop140and the alternative second filtration loop270.

FIG. 5illustrates a method400of fuel filtration using the filtration system220ofFIG. 3. The method400may comprise the following steps:

Step402: Fuel from the fuel tank124is drawn into the first pump142and then through the first filter144located on the pressure side of the first pump142. A portion of the fuel exiting the first filter144may be recirculated through the first filter144while a remaining portion flows into the alternative second filtration loop270. In the alternative second filtration loop270the fuel flows through the second pump172and then through the second filter174.

Step404: The controller110adjusts the speed of the first motor112and, if present, the second motor113, to distribute the fuel between the first filtration loop140and the second filtration loop270.

Step406: Based on input from the controller110, at least a portion of the fuel exiting the first filter144is recirculated via the first recirculation conduit162or the alternative fuel recirculation conduit164to the first filter144.

Step408: The fuel flowing out of the first filter144and not recirculated through the first filter144is pulled or drawn into the second pump172and then filtered through a second filter174via the interloop conduit178.

Step410: Fuel flowing out of the second filter174flows to the engine122.

Step412: Some fuel flowing through the engine122may avoid combustion and exit the engine122. Some of this fuel may flow back through an alternative second recirculation conduit202and then through the second pump172and is filtered again through the second filter174.

Step414: A portion of the fuel exiting the engine122may flow back to the fuel tank124via a return conduit136.

Although the dual loop filtration system120,220has been described herein with respect to fuel, it should be understood that the system could be used to filter other fluids, such as hydraulic fluids, coolants and lubricating oils. Unless specified otherwise, the term ‘fluid” may be used to describe liquids, gases, slurries, suspensions and combinations thereof, or any other similar flowable substances.

INDUSTRIAL APPLICABILITY

In operation, the teachings of the present disclosure may find applicability in many industries including, but not limited to, mining trucks, earth moving equipment, on and off highway trucks, construction machines, stationary engines, marine vessels and the like. The filtration system of the disclosure functions as a highly efficient fuel debris removal system, and may be used with diesel engines or perhaps with gasoline engines. The system provides an internal recirculating loop that provides multiple fuel passes through a first filter and a second filtration loop that provides one or more passes through a second filter using a second pump. The combination of a first impeller pump and a second gerotor pump, each with a filter, provides an extremely effective means of cleaning fuel.

The filtration system takes a first filtration loop comprising a low pressure, high flow pump and a first filter adds a second filtration loop comprising a high pressure, low flow pump that provides the necessary high pressure for engine requirements and a second filter.

Previous fuel systems filter the fuel before it is sent to the engine using a fuel pump that runs off of the engine speed. In the present system, the second (gerotor) pump may run off of the first (impeller) pump and thus may run independently of engine speed.

While the present disclosure has shown and described details of exemplary embodiments, it will be understood by one skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the disclosure as defined by claims supported by the written description and drawings. Further, where these exemplary embodiments (and other related derivations) are described with reference to a certain number of elements it will be understood that other exemplary embodiments may be practiced utilizing either less than or more than the certain number of elements.