Air Filtration for Mobile Mining Machines

Abstract

The mobile mining machine includes a base, a main housing supported on the base, and an air filter unit configured to provide filtered air to the main housing. The air filter unit includes a dirty air inlet, a filtered air outlet, and a filter chamber, the filter chamber being fluidly disposed between the dirty air inlet and the filtered air outlet, the filter chamber accommodating a filter element. The dirty air inlet is located vertically below the filter chamber.

Description

[0001] This application is a divisional application of the Chinese invention patent application filed on May 2, 2018, with application number 201810409506.6 and titled “AIR FILTRATION FOR MOBILE MINING MACHINES”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to U.S. Provisional Application No. 62 / 500,460, filed May 2, 2017, the entire contents of which are incorporated herein by reference. Technical Field

[0004] The present application relates to an air filter assembly. Specifically, the present application relates to an air filter assembly for a mobile mining machine, such as a mining shovel, an electrically-driven blast hole drill, a mobile mining crusher, a dragline, etc. Summary of the invention

[0005] One aspect of the present application provides a mobile mining machine, which includes a base, a main housing supported on the base, and an air filter unit for providing filtered air to the main housing. The air filter unit includes a dirty air inlet, a filtered air outlet, and a filter chamber, wherein the filter chamber is fluidly arranged between the dirty air inlet and the filtered air outlet, and a filter element is accommodated in the filter chamber. The dirty air inlet is located vertically below the filter chamber.

[0006] Another aspect of the present application provides a method of operating an air filtration unit of a mobile mining machine. The method includes drawing air into the air filtration unit through a dirty air inlet, capturing contaminants in the air on a filter element, exhausting the filtered air through a filtered air outlet, and exhausting at least a portion of the contaminants captured on the filter element through the dirty air inlet.

[0007] Another aspect of the present application provides a method of regulating air temperature within a housing of a mobile mining machine. The method includes supplying filtered ambient air into a first compartment of the housing through a first air filter unit, supplying filtered ambient air into a second compartment of the housing through a second air filter unit, the second compartment being at least partially isolated from the first compartment, and varying power supplied to a blower of the second air filter unit independently of the first air filter unit to maintain a target temperature within the second compartment.

[0008] Other aspects of the application will become apparent by consideration of the detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a perspective view of a mobile mining machine according to one embodiment of the present application.

[0010] Figure 2 yes Figure 1 A top view of a mobile mining machine, with the main housing and other components of the mobile mining machine removed for clarity.

[0011] Figure 3 yes Figure 1 A partial perspective view of a mobile mining machine with various components removed for clarity.

[0012] Figure 4 yes Figure 1 A partial perspective view of a mobile mining machine showing an air filtration assembly with various components removed for clarity.

[0013] Figure 5 yes Figure 4 Side view of an air filter assembly.

[0014] Figure 6 yes Figure 4 Top view of an air filter assembly.

[0015] Figure 7 yes Figure 1 A top perspective view of the counterweight box of a mobile mining machine.

[0016] Figure 8 yes Figure 7 Top view of the weight box.

[0017] Fig. 9 yes Figure 7 Bottom perspective view of the weight box.

[0018] Fig.10 yes Figure 7 Bottom view of the weight box.

[0019] Fig.11 is a perspective view of a mobile mining machine according to another embodiment of the present application.

[0020] Fig.12 yes Fig.11 Partial side view of a mobile mining machine.

[0021] Fig.13 yes Fig.11 A partial perspective view of an air filtration assembly for a mobile mining machine.

[0022] Fig.14 A schematic diagram of a conventional mobile mining machine air filtration system.

[0023] Fig.15 yes Fig.14 A perspective view of a conventional air filtration system.

[0024] Fig.16 yes Fig.14 A perspective view of a dirt removal assembly of a conventional air filtration system. DETAILED DESCRIPTION

[0025] Before explaining any embodiments of the present application in detail, it will be understood that the application of the present application should not be limited to the structural details and component arrangements disclosed in the following description or the following drawings. The present application may include other embodiments, or be practiced or implemented in various ways.

[0026] refer to Figure 1 , a mobile mining machine (an electrically driven mining shovel 10 in the illustrated embodiment) includes a base 14, a boom 18, a first member or handle 22, and a bucket 26. The boom 18 is connected to the base 14, the handle 22 is connected to the boom 18, and the bucket 26 is connected to the handle 22. In the illustrated embodiment, the base 14 is supported on a crawler track 34. In addition, the base 14 can be rotatable relative to the crawler track 34. The mining shovel 10 further includes a main housing 38 connected and supported on the base 14. The main housing 38 includes a top 40. The base 14 defines a deck 42 on which the main housing 38 is located. The deck 42 shown includes a walkway 46 that allows an operator to move around the deck 42, a platform 43 ( Figure 2 ) and counterweight box 44.

[0027] Continue to refer Figure 1 In the illustrated embodiment, the boom 18, handle 22, and bucket 26 are connected to the base 14 at a first end 50 of the base 14. An operator station 54 (e.g., an operator cab) is located proximate the first end 50 of the base 14. The counterweight tank 44 is defined at a second end 62 opposite the first end 50. In certain embodiments, the counterweight tank 44 may be loaded with a suitable counterweight material to offset the weight of the material collected in the bucket 26.

[0028] The mining shovel 10 further includes an air filter assembly 66 located at the back of the main housing 38, near the counterweight box 44. The air filter assembly 66 is shown connected to the platform 42 without being supported by the top 40 of the main housing 38. The main housing 38 houses the motor, drive, electronics, gearbox and other components that require filtered air cooling. The air filter assembly 66 is configured to provide filtered air to the main housing 38, which can be used to cool these components.

[0029] refer to Figure 2, the main housing 38 at least partially encloses, for example, the air compressor 70, the first hoist motor 74, the second hoist motor 78, the electric drive 82, the collector 86, two swing transmissions 91, and the lubricant tank 98. In addition to providing filtered air for cooling purposes, the air filter 66 can also be used to maintain a positive pressure within the main housing 38. In particular, a pressurized air blower (not shown) can be used to blow air to the hoist motors 74, 78, the electric drive 82, etc., which may draw air from the main housing 38. If a positive air pressure is not maintained in the main housing 38, a vacuum may be formed, thereby drawing dust and debris into the main housing 38. By providing a source of pressurized filtered air, the air filter assembly 66 advantageously prevents the formation of a vacuum in the main housing 38.

[0030] Reference Figure 1-3 , the illustrated air filter assembly 66 includes two air filter units 106 that are connected to the deck 42 and located on the counterweight box 44. The air filter units 106 are disposed on opposite lateral sides of an electrical room 100 that may contain one or more transformers or other electrical components of the mining shovel 10. In alternative embodiments, the air filter assembly 66 may include one, two, or more than two air filter units 106.

[0031] As in Figure 4 As best shown in FIG. 4 , each air filter unit 106 includes a dirty air inlet 110 and a filtered air outlet 114. The dirty air inlet 110 is connected to the deck 42 and is in fluid communication with a passage or opening 118 that extends vertically through the counterweight box 44 of the deck 42. In the illustrated embodiment, the opening 118 extends vertically through the counterweight box 44. Therefore, each air filter unit 106 is configured to draw air from below the deck 42. The deck 42 inhibits rain or water from entering the dirty air inlet 110, advantageously eliminating the need to set a separate top above the dirty air inlet 110. The filtered air outlet 114 is connected to the rear wall 130 of the main housing 38. In some embodiments, the main housing 38 extends to a degree that at least partially surrounds the air filter unit 106. In other embodiments, the air filter unit 106 is located on a platform 43 within the main housing 38, separated from the counterweight box 44. In such an embodiment, the dirty air intake is in fluid communication with the external environment through an opening formed in the platform 43 .

[0032] refer to Figure 7-10 , the opening 118 in the deck 42 includes a first cross-section 122 ( Figure 7 and 8 ) and a second cross section 126 at the bottom side of the deck 42 ( Fig. 9 and10 ), the second cross-section 126 is larger than the first cross-section 122. The first cross-section 122 is closer to the dirty air inlet 110 of the corresponding air filter unit 106 than the second cross-section 126. In this way, the dirt-laden air drawn in through the opening 118 is accelerated as the dirty air moves toward the dirty air inlet 110 of the air filter unit 106. Because the bottom of the opening 118 has a larger cross-sectional area 126, the dirty air may be drawn into the opening at a relatively low velocity, which may prevent large debris particles from being entrained in the airflow.

[0033] Reference Figure 4-6 , for the sake of clarity, a portion of one of the air filter units 106 is hidden. Each air filter unit 106 further includes a filter chamber 134 and a plurality of filter elements 138 positioned and contained in the filter chamber 134, and the filter chamber 134 is configured between the dirty air inlet 110 and the filtered air outlet 114. In the illustrated embodiment, the filter element 138 is a cartridge-type cylindrical air filter with a breathable filter medium. In other embodiments, other types of filter elements 138 can be used. The filter element 138 is configured to allow dirty air to enter the filter element 138 along the radial direction of each filter element 138. Dirt is captured by the filter medium and retained on the outer circumferential surface of each filter element 138. After passing through the filter element 138, the filtered air enters the filtered air chamber 146, which is fluidly connected to the filtered air outlet 114. In other words, the filtered air chamber 146 is fluidly arranged between the filtered air outlet 114 and the filter chamber 134.

[0034] refer to Figure 5, the dirty air inlet 110 is located vertically below the filter chamber 134. Therefore, the filter chamber 134 is located vertically above the dirty air inlet 110. In this way, the air filter unit 106 is an upflow type filter unit. In other words, dirty air enters the bottom 106 of each unit and flows upward (i.e., upflow, in the vertical direction 158) to the filter chamber 134. In addition, the dirty air inlet 110 is located vertically below the filtered air outlet 114. In this description, "vertically above" and "vertically below" and other similar directional terms refer to the direction of the air filter unit 106 when it is installed on the mining shovel 10, with the above and below referring to the direction of the earth's gravity. The dirty air intake 110 and the filter chamber 134 are preferably arranged vertically (i.e., a vertical plane intersects at least a portion of the dirty air intake 110 and at least a portion of the filter chamber 134), but the dirty air intake 110 and the filter chamber 134 may be arranged in other ways to allow dirt to fall from the filter chamber 134 under the influence of gravity and be discharged through the dirty air intake 110. For example, the dirty air intake 110 can be offset from the filter chamber 134 in a horizontal direction while still being vertically located below the filter chamber 134. In such an embodiment, for example, the dirty air intake 110 and the filter chamber 134 can be connected by an inclined transition duct.

[0035] Each air filtration unit 106 further includes a fan assembly 150 operable to generate an air flow from the dirty air inlet 110 to the filtered air outlet 114. Specifically, the fan assembly 150 is operable to draw dirty air through the opening 118 in the deck 42, into the dirty air inlet 110, through the filter element 138, and out of the filtered air outlet 114. In the illustrated embodiment, the fan assembly 150 includes a centrifugal blower 151 driven by a motor 152. The fan assembly 150 is supported above the filtered air chamber 146 by a bracket 153, which is directly connected to the deck 42. The bracket 153 supports the weight of the fan assembly 150 to minimize stress on the remainder of the air filtration unit 106. The first air passage or duct 154 is between the filtered air chamber 146 and the air inlet of the centrifugal blower 151, and the second air passage or duct 155 is between the air outlet of the centrifugal blower 151 and the filtered air outlet 114 ( Figure 5 ). One or both of the ducts 154, 155 may be flexible to facilitate alignment during assembly. Flexible ducts 154, 155 may also advantageously reduce vibration transmission between the main housing 38 and the air filter unit 106 and between the fan assembly 150 and the filtered air chamber 146. In some embodiments, either or both of the fan assemblies 150 may be mounted directly to the main housing 38 (e.g., the rear wall 130). In these embodiments, the duct 154 may extend to connect the air inlet of the centrifugal blower 151 to the filtered air chamber 146.

[0036] Continue to refer Figure 5 In the illustrated embodiment, each air filter unit 106 further includes a filter cleaning mechanism 141. The filter cleaning mechanism 141 includes an air manifold 142 that stores a large amount of pressurized air and can release a stream of pressurized air (e.g., by actuation of one or more solenoid valves) through each filter element 138. The direction of the stream of pressurized air is preferably opposite to the direction of the operating air flow through the filter element 138 to remove dirt captured by the filter element 138. The filter cleaning mechanism 141 can operate based on a timer to send pressurized air to the filter element 138 at set time intervals (e.g., 30 second intervals). Alternatively, the filter cleaning mechanism 141 can operate based on a measurement result (e.g., a pressure reading), in response to an operator command, or in response to a change in operating conditions (e.g., when the fan assembly 150 is turned off). In the illustrated embodiment, a filter replacement indicator 147 is provided on the air filter unit 106. The filter replacement indicator 147 provides a visual indication to the operator that one or more filter elements 138 require maintenance or replacement. In certain embodiments, filter change indicator 147 may be a pressure gauge configured to measure the pressure drop in filter element 138. In other embodiments, various other indicators may be used.

[0037] In operation, the fan assembly 150 is energized to generate airflow through the air filter unit 106. In particular, dirty air is drawn upward through the opening 118 of the deck 42 and is accelerated as it approaches the dirty air inlet 110 of the air filter unit 106. The dirty air then flows vertically (i.e., upward in the direction of arrow 158) toward the filter chamber 134, where the surface of the filter element collects dirt 138 as the air flows through the filter media. The filtered air enters the filtered air chamber 146, and the fan assembly 150 then discharges the filtered air through the filtered air outlet 114 and into the main housing 38.

[0038] The air filter unit 106 can be operated in a filter cleaning mode, in which the air manifold 142 provides a blast of pressurized air to the filter element 138 to remove any debris from the filter element 138. Smaller debris particles may remain suspended within the filter chamber 134 and remain in the airflow, causing the small particles of debris to be trapped on the filter element 138 again. However, larger debris particles will fall downward to pass back through the dirty air intake 110. In other words, the dirty air intake 110 can also be considered a dirt outlet because when the air filter unit 106 is operated in the filter cleaning mode, the filtered dirt is discharged through the dirty air intake 110. The blast of air from the manifold 142 causes large particles of debris to leave the filter chamber 134 by gravity. Any smaller particles that remain suspended in the filter chamber 134 will gather and increase in size until they are large enough to fall through the dirty air intake 110 and the opening 118 without being re-entrained in the airflow generated by the fan assembly 150. The air filter unit 106 may also continue to operate in the filter cleaning mode for a period of time after the fan assembly 150 is turned off. Thus, the manifold will continue to provide pressurized air, and removed dirt and debris may fall through the filter element 138 without being re-entrained by the airflow generated by the fan assembly 150. In some embodiments, when the shovel 10 is stopped, the air filter unit 106 may automatically continue to operate in the filter cleaning mode for a predetermined period of time.

[0039] refer to Figure 2 In some embodiments, the main housing 38 may include a wall or curtain 162 that separates the main housing 38 into two compartments 38A and 38B. The two compartments 38A and 38B may be independently controlled by operating at least one of the two air filter units 106 using a variable frequency drive. Thus, when the outside temperature is very cold, for example, the air filter unit 106 may be operated to limit the amount of cold air entering the main housing 38. Specifically, if a compartment 38A has a different temperature requirement than compartment 38B depending on the components contained therein, the air filter unit 106 corresponding to component 38A is controlled by the variable frequency drive, while the other air filter unit 106 corresponding to compartment 38B may operate normally. In other words, the power supplied to the blower 151 of the air filter unit 106 corresponding to component 38A may be changed to maintain the target temperature within component 38A, and the change in power may be independent of the power supplied to the blower 151 of the other air filter unit 106. Various components, such as electronic components, may have critical temperature ranges for proper operation, and operating the air filtration unit 106 with a variable frequency drive is one way to regulate the blower fan speed to create a temperature controlled main housing 38 or a temperature controlled compartment 38B of the main housing 38.

[0040] refer to Figure 11-13, a mining shovel 310 according to another embodiment is shown. The shovel 310 is similar to the shovel 10, and only the differences are described herein, wherein similar structures are labeled with the same reference numerals increased by "300" (e.g., 18 and 318 both represent booms, etc.). The mining shovel 310 includes a base 314, a boom 318, a first member or handle 322, and a bucket 326. In the illustrated embodiment, an air filter assembly 366 is connected to the top 340 of the main housing 338. In particular, the air filter assembly 366 includes two air filter units 406 positioned on an open-air bracket 407. In the illustrated embodiment, the air filter units 406 share a common fan assembly 450. As before, the air filter unit 406 is an upflow type filter unit, and dirty air flows vertically upward from the dirty air inlet 410 to the filter chamber 434. In the illustrated embodiment, each air filter unit 406 includes a skirt 411 surrounding the dirty air intake 410 , which helps prevent rain or water from entering the air filter unit 406 .

[0041] The top 340 includes an angled portion 341 that is located below the dirty air intake 410. Similar to the air filter unit 106, the air filter unit 406 can be operated in a filter cleaning mode, using a blast of pressurized air to expel collected dirt through the dirty air intake 410. The angled portion 341 of the top 340 diverts the removed dirt away from the scoop 310. In other embodiments, any dirt collected on the top 340 is washed away during a rainstorm (i.e., weather), or manually removed by an operator.

[0042] refer to Figure 14-16 , a conventional air filter assembly 210 for a mining shovel uses a conventional downflow air filter 214. In particular, the downflow air filter unit 214 includes a top portion defining an air intake hood 218, a dirty air inlet 222, a filter chamber 226, a filtered air chamber 230, and a filtered air outlet 234 ( Fig.14 ). The downflow air filter unit 214 delivers air from the air intake hood 218 in a downward direction toward the dirty air intake 22. Since the dirty air intake 222 faces upward, the air intake hood 218 is required to prevent rain or water from entering the dirty air intake 222. In addition, due to size limitations and airflow requirements, the downflow air filter unit 214 must be mounted on the top 238 of the mining shovel.

[0043] Continue to refer Figure 14-16 In the downflow type air filter unit 214, the dirt collected in the filter chamber 226 is removed by a separate dirt removal assembly 242. The dirt removal assembly 242 includes an auger 246, a drive motor (not shown but on the side 250) for driving the auger 246, and an air lock 254 ( Fig.16). The dirt removal assembly 242 adds additional cost and complexity, and the additional components increase maintenance and potential failure points. In contrast, the upflow air filtration unit 106, 406 described above does not require such a dirt removal assembly, because the collected dirt simply falls back through the dirty air intake 110, 410 under the influence of gravity.

[0044] Thus, the upflow air filter unit 106, 406 provides many advantages over the conventional air filter unit 214. For example, first, the upflow air filter unit 106, 406 does not require an additional cover to prevent water from entering. Second, as described above, the upflow air filter unit 106, 406 does not require a dirt removal assembly to transfer the collected dirt away from the filter chamber 134, 434. Instead, when the upflow air filter unit 106, 406 is operated in the filter cleaning mode, the collected dirt simply falls through the dirty air intake 110, 410 again.

[0045] Various features of the application are set forth in the following claims.

Claims

1. A method for operating an air filtration unit of a mobile mining machine, It is characterized in that The method comprises: drawing air into the air filtration unit through a dirty air intake; Captures dirt in the air onto the filter element; Exhaust filtered air through the filtered air outlet; supplying the filtered air into a main housing of the mobile mining machine; and exhausting at least a portion of the contaminants captured on the filter element through the dirty air intake; wherein the step of discharging at least a portion of the dirt captured on the filter element comprises shutting off the fan assembly of the air filter unit and displacing the dirt from the filter element with a blast of pressurized air, thereby causing the displaced dirt to fall from the filter element and pass through the dirty air intake under the influence of gravity, Wherein the step of drawing air into the air filter unit comprises drawing air through an opening in a deck of the mobile mining machine.

2. The method according to claim 1, It is characterized in that The filter element is positioned vertically above the dirty air intake port.

3. The method according to claim 1, It is characterized in that The air filter unit is located on top of the main housing.

4. The method according to claim 3, It is characterized in that The top portion includes an inclined portion that is positioned vertically below the dirty air inlet, wherein dirt collected by the filter element is discharged through the dirty air inlet onto the inclined portion under the influence of gravity.

5. The method according to claim 1, It is characterized in that The air filter unit is located on a counterweight box of the mobile mining machine.

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