Patent Application
20140284027
The present disclosure relates generally to a cleaning system and, more particularly, to a system for cleaning heat exchangers.
Most mobile machines are powered by an internal combustion engine, for example a diesel engine, a gasoline engine, or a gaseous-fuel powered engine. Each of these engines combust a mixture of fuel and air to generate a mechanical power output used to propel the machine. With the purpose to ensure optimum combustion of the fuel/air mixture and protect components of the engine from damaging extremes, temperatures of the engine and air drawn into the engine for combustion should be tightly controlled.
Typical internal combustion engines are cooled by way of one or more heat exchangers and an axial cooling fan disposed adjacent (e.g., in front of or behind) the heat exchangers. Coolants from the engine are circulated through the heat exchangers, while the axial cooling fan directs a flow of fresh air through the heat exchangers to absorb heat from the coolants. The coolants, having dissipated heat to the air, are then circulated back through the engine to cool the engine. The air, after having absorbed heat from the heat exchanger, is directed to the atmosphere.
Unfortunately, debris carried by the cooling air can build up in the heat exchangers, blocking flow paths through the heat exchangers. If left unchecked, an efficiency of the heat exchangers can reduce over time due to the blockage. Accordingly, the debris should be periodically removed from the heat exchangers to help ensure proper operation of the engine.
Conventionally, the debris is removed from the heat exchangers by way of a hand-held wand that discharges pressurized air through the heat exchangers in reverse direction. This reverse flow of high-pressure air forces the debris back out of the heat exchangers in the direction that it originally entered the heat exchangers, thereby clearing channels of the heat exchangers for more efficient cooling. This conventional method of cleaning heat exchangers can be labor intensive and only moderately successful in smaller applications where the service technician can reach all areas of the heat exchangers.
An attempt to improve heat exchanger cleaning is disclosed in JP Patent Publication 2005/147428 of Hiroyuki that published on Jun. 9, 2005 (the '428 publication). Specifically, the '428 publication describes a device for use in manually cleaning a heat exchanger. The device includes an arrangement of air nozzles coupled together in a row and suspended at one side of a heat exchanger by way of ropes connected to the row of nozzles at opposing ends. A supply of air from a compressor is directed to the nozzles as the ropes are manually pulled by a service technician from outside of an associated fan shroud. Pulling the ropes causes the nozzles to move upward in front of the heat exchanger, while releasing the ropes allows gravity to pull the nozzles down. In this manner, the air discharged from the nozzles washes areas of the heat exchanger that could not normally be reached by the technician.
Although the device of the '428 publication may enhance heat exchanger cleaning, it may still be problematic. In particular, the process may still be labor intensive and prone to operator error. In addition, the system may lack durability.
The disclosed cleaning system is directed to overcoming one or more of the problems set forth above and/or other problems of the prior art.
In one aspect, the present disclosure is directed to a cleaning system for use with a heat exchanger. The cleaning system may include a nozzle configured to discharge a flow of fluid, and an actuator operatively attachable to a side of the heat exchanger and configured to move the nozzle across a face of the heat exchanger. The cleaning system may also include a control panel mounted remotely from the actuator and connected to the actuator and to the nozzle. The control panel may be configured to receive operator input indicative of desired movement of the nozzle, and to selectively energize the actuator based on the operator input.
In another aspect, the present disclosure is directed to a method of cleaning a heat exchanger. The method may include directing fluid through a nozzle toward the heat exchanger. The method may also include receiving an input indicative of a desire to move the fluid nozzle, and selectively moving the nozzle across a face of the heat exchangers in response to the input during fluid discharge.
As shown in
Each of heat exchangers 26 may be configured to dissipate heat from the primary fluids passing through them to the flow of air generated by fan 28. These primary fluids may be water, glycol, a water/glycol mixture, air, a blended air mixture, or oil (e.g., engine oil hydraulic oil, transmission oil, brake oil, etc.). Each of heat exchangers 26 may a liquid-to-air type of exchanger or an air-to-air type of heat exchanger, as desired. In either of these embodiments, the flow of air generated by fan 28 may be drawn from air inlets 22 through channels of the respective heat exchangers 26, such that heat from the primary fluids within adjacent channels is transferred to the air. In this manner, the primary fluids passing through other components of machine 10 may be cooled to desired operating temperatures. While fan 28, in the disclosed exemplary embodiment, is situated to draw the flow of air through heat exchanger 26, it is contemplated that fan 28 could be alternatively situated to push the air through heat exchangers 26 and out inlets 22, if desired.
The heat exchangers 26 located in upper row 32 and second layer 36, because of their height above frame 12 and their recessed location between first layer 34 and fan 28, may be difficult for a service technician to clean properly. Accordingly, cooling arrangement 24 may be equipped with a cleaning system 38 that facilitates remote cleaning of these heat exchangers 26. Cleaning system 38 may include, among other things, one or more fluid nozzles 40 associated with each of the hard-to-reach heat exchangers 26, an actuator 42 connected to each nozzle 40, and a control panel 44 mounted remotely from each nozzle 40 and actuator 42. Control panel 44 may be connected to each nozzle 40 via a fluid supply line 46 and to each actuator 42 via a power supply line 48.
Each nozzle 40 may embody any type of nozzle known in the art for discharging a high-pressure fluid toward an associated heat exchanger 26. In the embodiment of
Actuator 42 may be any type of actuator that functions to move one or more nozzles 40 across a face of an associated heat exchanger 26. In the disclosed embodiment, each actuator 42 is a linear actuator that moves a single nozzle 40 in a generally vertical direction aligned with gravity, between a top edge of upper row 32 of heat exchangers 26 and an opposing lower edge. It is contemplated that actuator 42 could alternatively move horizontally, if desired. However, such movement may add unnecessary stress to actuator 42 due to a cantilevered mass of nozzle 40 that would be created in such an arrangement. Exemplary types of linear actuators 42 include a screw type actuator having a lead screw 50 and a lead nut 52, one of which is rotated by a motor 54; a rack and pinion arrangement; a cam arrangement; or a cylinder arrangement. It is also contemplated that actuator 42 could alternatively be a rotary actuator, if desired, that rotates nozzle 40 around the face of the associated heat exchanger 26. In the disclosed embodiment, actuator 42 is electrically powered, although other forms of power are also possible (e.g., pneumatically powered, hydraulically powered, mechanically powered, etc.).
Control panel 44 may provide an interface for use by a service technician in controlling operations of cleaning system 38. Specifically, control panel 44 may include a control housing 55 recessed within (or otherwise mounted to) machine housing 18, and a plurality of interface devices located within housing 55. The interface devices may be accessed by the service technician from outside of enclosure 16, while the service technician is standing on frame 12. The interface devices may include, among other things, a fluid control valve 56 associated with each fluid supply line 46, a switch 58 associated with each power supply line 48, and a fluid supply port 60 in communication with fluid control valves 56. It is contemplated that control panel 44 may include additional interface and/or serviceable components, if desired, such as a fluid filter, a pressure regulator, and other similar devices known in the art.
Each fluid control valve 56 may be a manually operable valve having a lever movable between a first position and a second position. When the lever is in the first position (generally horizontal position shown in
Switch 58 may be, for example, a toggle switch that is movable between multiple positions to control the motion of actuator 42. For example, switch 58 may be movable from a neutral position (shown in
Fluid supply port 60 may allow an external (e.g., offboard) source of pressurized air (or other fluid) to be selectively used to supply nozzle 40. For example, a compressor or tank located onboard a service truck (not shown) may be selectively connected to fluid supply port 60 to supply nozzles 40 with the air required to clean heat exchangers 26. In the disclosed embodiment, fluid supply port 60 is a compression fitting, although other types of fittings may also be used, if desired. It is also contemplated that an onboard source of pressurized air (e.g., an engine-driven compressor or turbocharger) may be used to supply nozzles 40.
The disclosed cleaning system may be applicable to any type and configuration of heat exchangers known in the art. However, the disclosed cleaning system may be particularly applicable to cooling arrangements having heat exchangers that are difficult to access, for example elevated heat exchangers or heat exchangers buried between layers of other components. The disclosed cleaning system may allow for cleaning of these difficult-to-access heat exchangers from a remote location that is more accessible by a service technician. The disclosed cleaning system may be used while the associated engine (or engine system—e.g., power train, hydraulics, brakes, etc.) is turned off, as the disclosed cleaning system may be provided with cleaning fluid and power from an external and offboard source. Operation of cleaning system 38 will now be described in detail.
After a period of operation of machine 10, dust and debris may have accumulated within channels of heat exchangers 26. This dust and debris, if not removed, may block the flow of cooling air through the channels and thereby reduce an amount of heat that can be absorbed by the air. As a result, engine performance (or performance of the system connected to the heat exchangers 26) may decrease and, in some situations, damage may occur. Accordingly, the channels of heat exchangers 26 may be periodically cleaned of dust and debris. Cleaning may be accomplished by selectively reversing the flow of air through the channels of heat exchangers 26.
Cleaning system 38 may be used to generate the reverse flow of air through heat exchangers 26. In particular, when engine 14 of machine 10 is turned off, so as to stop the flow of air generated by fan 28, a service technician may board machine 10. The service technician may connect an offboard air supply (e.g., a compressor or tank) to fluid supply port 60 within control panel 44, and move one or both of the levers of control valves 56 to their flow passing positions. At about the same time, the service technician may move one or both of switches 58 up and down to energize actuators 42 and create corresponding motions of nozzles 40. The service technician may continue this operation until a prescribed amount of time has elapsed, until heat exchangers 26 are visibly clean, until a change in pressure and/or flow rate of air through heat exchangers 26 is observed, until debris is no longer being dislodged from heat exchangers 26, or until another condition has been met. The service technician may then return control valves 56 and switches 58 to their original positions and disconnect the source of pressurized air from fluid supply port 60. The debris dislodged from heat exchanger 26 may fall under the force of gravity down between first and second layers 34, 36 of heat exchangers 26. In some applications, frame 12 may have openings at this location, such that the dislodged debris may exit enclosure 16. In other applications, the service technician may be required to manually remove the fallen debris from frame 12.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed cleaning system without departing from the scope of the disclosure. Other embodiments of the cleaning system will be apparent to those skilled in the art from consideration of the specification and practice of the cleaning disclosed herein. For example, it is contemplated that cleaning system 38 could be an automated system, if desired, that is selectively and automatically activated when engine 14 is turned off. In this alternative embodiment, nozzles 40 may be supplied with pressurized air from an onboard tank. It is further contemplated that control panel 44 could alternatively be located elsewhere on machine 10, if desired, for example within an operator cabin. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.
