The present disclosure relates to a hydraulic mining shovel, and more particularly to a hydraulic mining shovel configuration including an exhaust aftertreatment module with a selective catalytic reduction unit.
In surface mining, hydraulic mining shovels (also referred to as large hydraulic excavators) may be used for digging and extracting material and minerals. For providing power to various components of the hydraulic mining shovel, the same may include one or more engines. For example, those engines may be electric motors or internal combustion engines such as diesel engines.
Due to an increasing environmental consciousness and emission regulations, recent developments of engine manufacturers aim to reduce the emissions of internal combustion engines, for example emission of nitrogen oxides that may be generated during combustion in the internal combustion engine. A technique for reducing those nitrogen oxides is the so-called selective catalytic reduction (SCR). Typically, SCR aftertreatment units receive a stream of exhaust gas from an outlet of the internal combustion engine and treat the exhaust gas with a reductant such as urea to reduce nitrogen oxides therein to diatomic nitrogen and water.
The present disclosure is directed, at least in part, to improving or overcoming one or more aspects of prior systems.
In one aspect of the present disclosure, a hydraulic mining shovel is disclosed. The hydraulic mining shovel may comprise a main frame extending along a central longitudinal axis, and a power module mounted onto the main frame and including a first internal combustion engine and a second internal combustion engine. The hydraulic mining shovel may further comprise a counterweight module mounted onto the main frame and including a counterweight for maintaining stability of the hydraulic mining shovel. Still further, the hydraulic mining shovel may comprise a first exhaust aftertreatment module and a second exhaust aftertreatment module. Each of the first exhaust aftertreatment module and the second exhaust aftertreatment module may be mounted onto the counterweight module and may include a reductant tank and pump unit and a selective catalytic reduction unit. The reductant tank and pump unit may be configured to store and supply a reductant, and the selective catalytic reduction unit may be fluidly connected to the respective reductant tank and pump unit for receiving the reductant. The first exhaust aftertreatment module may be fluidly connected to the first internal combustion engine. The second exhaust aftertreatment module may be fluidly connected to the second internal combustion engine. The first exhaust aftertreatment module and the second exhaust aftertreatment module may be configured and arranged substantially mirror-symmetrically at opposing sides of the counterweight module with respect to the central longitudinal axis.
In another aspect of the present disclosure, a carrier structure is disclosed. The carrier structure may be configured to support a reductant pump and tank unit, and a selective catalytic reduction unit. Further, the carrier structure may be configured to be releasably mounted on a hydraulic mining shovel, particularly onto a counterweight module of the hydraulic mining shovel.
Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.
The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate exemplary embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure. In the drawings:
The following is a detailed description of exemplary embodiments of the present disclosure. The exemplary embodiments described therein and illustrated in the drawings are intended to teach the principles of the present disclosure, enabling those of ordinary skill in the art to implement and use the present disclosure in many different environments and for many different applications. Therefore, the exemplary embodiments are not intended to be, and should not be considered as, a limiting description of the scope of patent protection. Rather, the scope of patent protection shall be defined by the appended claims.
The present disclosure is based in part on the realization that a hydraulic mining shovel poses specific and challenging requirements for an optimized integration of an SCR aftertreatment unit. Particularly, it was found that an SCR aftertreatment unit and its components sum up to a considerable size, because the large internal combustion engines of a hydraulic mining shovel generate large amounts of exhaust gas to be treated by the SCR aftertreatment unit. Accordingly, herein, a modular construction of the SCR aftertreatment units is suggested, which includes all required components, partly integrated into sub-units for integrating different functionalities. Additionally, an arrangement of the SCR aftertreatment units is suggested, which considers the specific requirements of a hydraulic mining shovel in terms of collision avoidance, operator and machine safety, space-saving arrangement, and homogeneous mass distribution as is described in greater detail later on.
The present disclosure is further based in part on the realization that a modular configuration of the aftertreatment unit in coordination with further modules and components of the hydraulic mining shovel allows to provide a plurality of construction kits for hydraulic mining shovels having a plurality of standardized parts while providing different exhaust aftertreatment capabilities. Specifically, based on national and regional emission regulations and customer requirements, a hydraulic mining shovel may require an SCR unit or not. By configuring the exhaust aftertreatment unit as a module, the same may be included or not as desired without affecting the presence, configuration and arrangement of the remaining parts and components of the hydraulic mining shovel such as the internal combustion engine(s). Furthermore, a modular configuration of the hydraulic mining shovel with respect to the exhaust aftertreatment module may facilitate retrofitting the exhaust aftertreatment module without requiring modifications and rearrangement of other components of the hydraulic mining shovel. Particularly, connecting parts and points for mounting the aftertreatment module and connecting the same to the internal combustion engine may be already present in a required configuration for receiving the aftertreatment module.
Referring now to the drawings for describing an exemplary hydraulic mining shovel 100 as shown in
In the shown embodiment of
Superstructure 102 includes a plurality of modules mounted to one another and/or to a main frame 112 extending longitudinally in a bottom region of superstructure 102 (in
The modules include a power module 114, a counterweight module 116 with a counterweight 117, an operator cab module 118, a first exhaust aftertreatment module 120, and a second exhaust aftertreatment module and an oil cooler module (see
In a bottom region of power module 114, a movable service unit 115 is provided. Said service unit 115 may selectively move in direction to ground surface 122 for providing access to refill inlets and/or control panels for an operator on ground level. During operation, service unit 115 may be retracted into an accommodation chamber in power module 114, for example by means of a hydraulic actuator. In some embodiments, the retraction-and-extension-mechanism for service unit 115 may be configured to pivot service unit 115 out of its accommodation chamber.
Further, undercarriage 104 includes a propulsion device for propelling hydraulic mining shovel 100 on a work surface 122. For example, the propulsion device may include track chains 124 and drive motors for driving track chains 124.
Attachment 106 includes work implement 108 such as a face shovel, which is movably mounted to a front end of a stick 126 that is in turn movably mounted to a boom 128. A plurality of hydraulic actuators 130 allow moving work implement 108, stick 126 and boom 128 as desired during mining operation.
Turning to
As noted above and as can be seen in
Further, main frame 112 extends along a central longitudinal axis A and supports modules 114, 116, 118 and 132. In this context it should be noted that main frame 112 is shown in part only as it is partly overlapped, in particular, by power module 114 and counterweight module 116. Besides mounting structures for attachment 106 (see
Inside power module 114, first and second internal combustion engines 138 and 140 are accommodated such that their longitudinal axes (crankshaft axes) B1, B2 extend parallel to central longitudinal axis A of main frame 112. Additionally, for providing hydraulic power to various components of hydraulic mining shovel 100, first and second pump transfer gearboxes 142 and 144 are operationally connected to respective outputs of first and second internal combustion engines 138 and 140 via respective couplings 146, 148. For example, engines 138 and 140 are configured as diesel engines. Further, as depicted in
Intake air is provided to internal combustion engines 138, 140 by first and second air intake units 147 and 149 which are mounted on a top deck 150 of power module 114. Said air intake units 147, 149 are fluidly connected to engines 138, 140 via suitable piping not shown in detail. Additionally, air intake units 147 and 149 may be equipped with air filters for cleaning ambient air before supplying the same to engines 138, 140.
For maintaining stability of hydraulic mining shovel 100 during operation, counterweight module 116 includes counterweight 117 (see
On a top deck 164 of counterweight module 116, first and second exhaust aftertreatment modules 120 and 121 are mounted. Each exhaust aftertreatment module 120, 121 includes a respective reductant tank and pump unit 160, 162 and a respective selective catalytic reduction (SCR) unit 156, 158. Further, first and second exhaust aftertreatment modules 120, 121 are configured and arranged mirror-symmetrically at opposing sides of top deck 164 of counterweight module 116 with respect to central longitudinal axis A. Additionally, SCR units 156, 158 are mounted closer to central longitudinal axis A than reductant tank and pump units 160, 162. Alternatively, reductant tank and pump units 160, 162 may be mounted closer to central longitudinal axis A than SCR units 156, 158. Further, in the shown configuration of
In some embodiments, first and second exhaust aftertreatment modules 120, 121 may be configured and arranged merely substantially mirror-symmetrically at opposing sides of top deck 164 of counterweight module 116 with respect to central longitudinal axis A. For example, a substantially mirror-symmetrically arrangement may include installation tolerances, and/or merely relatively small deviations from a corresponding mirror-symmetrical arrangement, for instance, a single digit percentage deviation relative to a corresponding absolute mirror-symmetrical arrangement.
Above described arrangement and configuration of exhaust aftertreatment modules 120 and 121 provides a couple of advantages. For example, first and second exhaust aftertreatment modules 120 and 121 are substantially isolated against vibrations of internal combustion engines 138 and 140 due to the installation onto counterweight module 116. Further, first and second exhaust aftertreatment modules 120 and 121 are arranged to prevent occurrence of any collisions with material to be excavated and other vehicles. The reason is that modules 120 and 121 do not or at least not substantially project beyond counterweight module 116 in directions of central longitudinal axis A and perpendicular to central longitudinal axis A. Still further, as can be seen in conjunction with
First reductant tank and pump units 160, 162 may be integrated units including a storage chamber for storing a reductant, and at least one pump for pumping the reductant from the storage chamber to the respective SCR units 156 or 158. By configuring first reductant tank and pump units 160, 162 as integrated units, a space-saving configuration of those components is provided, which eases and quickens installation as the integrated units can be fully assembled before installation on hydraulic mining shovel 100.
Each storage chamber may have a capacity of several hundred liters, for example more than 500 liters, because the to-be-treated exhaust gas amount generated by engines 138 and 140 may be relatively large. The storage capacity may be configured to provide enough reductant for at least one work shift, preferably at least one work day. For refilling reductant, an operator may connect a supply pipe to a reductant refill inlet(s) 166 (see
Reductant is supplied from first and second tank and pump units 160 and 162 to SCR units 156 and 158, respectively, via fluid connections (not shown). Said SCR units 156 and 158 include exhaust passages being fluidly connected to exhaust outlets of internal combustion engines 138 and 140, for example, with flexible piping, because of potential relative movements between power module 114 and counterweight module 116. In operation, SCR units 156 and 158 inject reductant from tank and pump units 160 and 162 into respective exhaust gas streams provided by engines 138 and 140, and passing the exhaust passages of SCR units 156 and 158. The injected reductant together with a suitable catalyzer structure housed in SCR units 156 and 158 ensures that a considerable amount of nitrogen oxides present in the exhaust gas streams is reduced to diatomic nitrogen and water. Then, the cleaned exhaust gas leaves SCR units 156 and 158 to the environment.
Furthermore, operator cab module 118 may provide an operator seat 168 and a control panel 167 for an operator to control hydraulic mining shovel 100 as desired. For example, control panel 167 may include joysticks, levers, buttons, and the like for propelling hydraulic mining shovel, and controlling operation of implement 108, attachment 106, and slewing gear device 110. In some embodiments, operator cab module 118 may further include interfaces, for example a display, for conveying information such as machine parameters and environmental conditions to an operator. Additionally or alternatively, a remote control and/or interface unit for the operator may be provided outside of operator cab module 118, for example remote from hydraulic mining shovel 100.
Oil cooler module 132 is provided on an opposite side of mainframe 112 with respect to operator cab module 118. In oil cooler module 132, at least one oil cooler 170 is accommodated.
Referring now to
Specifically, in the embodiment shown in
Referring now to
As can be seen in
In some embodiments, a common carrier structure may be provided for both exhaust aftertreatment modules 120 and 121. For example, the common carrier structure may be formed as an integral unit, or as two separate carrier structures 172 fastened to one another. By providing a common carrier structure, first and second exhaust aftertreatment modules may be lifted and/or installed on hydraulic mining shovel 100 as a whole in one single step.
For allowing a quick installation, retrofit and replacement if required, carrier structure 172 may further include fastening units for realeasably securing exhaust aftertreatment module 121′ onto counterweight module 116 (see
Furthermore, a drip pan 174 is disposed below reductant tank and pump unit 162′ such that in the event of a leakage, the leaking highly-corrosive reductant can be collected in drip pan 174 instead of flowing into power module 114 and/or counterweight module 116 (see
As the reductant storage chamber of reductant tank and pump unit 162′ may store several hundred liters of reductant, a volume of drip pan 174 may be not sufficient to collect the entire leaking reductant. A drainage mechanism may be included which ensures that in case drip pan 174 is almost entirely filled, the reductant is drained from the drip pan in a desired manner to ensure that the leaking reductant does not come into contact with any endangered component. For example, a drainage mechanism may include relatively low-height side walls 176 of drip pan 174 in a region which would allow reductant to overflow in a direction away from power module 114.
Still further, a heat insulation wall 178 may be arranged between reductant tank and pump unit 162′ and SCR unit 158 to reduce a heat transfer from SCR unit 158 to reductant tank and pump unit 162′. Said heat insulation wall 178 allows to arrange reductant tank and pump unit 162′ and SCR unit 158 close together although the reductant in the storage chamber of reductant tank and pump unit 162′ is very sensitive to heat. For example, heat insulation wall 178 may include a heat insulating material.
Moreover, heat insulation wall 178 may be releasably mounted to carrier structure 172 such that the same can be removed in case of very low temperatures, for example during winter, to allow a certain heat transfer which (slightly) warms the reductant, because the same may be also very sensitive to cold.
For protecting exhaust aftertreatment module 121′ against direct sunlight, debris and oil vapor etc., module 121′ may further include a protection cover 180 covering reductant tank and pump unit 162′ and SCR unit 158. Protection cover 180 may include lifting mounts 182 for moving and installing the same. In some embodiments, protection cover 180 may cover reductant tank and pump unit 162′ or SCR unit 158 only.
As one skilled in the art will appreciate, application of carrier structure 172 and its features is not limited to mirror-symmetrical arrangement and configurations of exhaust aftertreatment modules 120, 121 as shown in
The hydraulic mining shovel configuration disclosed herein is particularly applicable in hydraulic mining shovels requiring an exhaust aftertreatment device including an SCR unit.
By configuring the exhaust aftertreatment unit as a module in an arrangement and configuration as exemplary disclosed herein, various advantages may be achieved. For example, exhaust aftertreatment modules 120, 121 are substantially isolated against vibrations of internal combustion engines 138, 140 due to their arrangement onto counterweight module 116. Further, the relatively small overall dimensions of exhaust aftertreatment modules 120, 121 in combination with the non-projecting (or at least not substantially projecting) arrangement onto counterweight module 116 helps to avoid any collisions with material walls and vehicles. Additionally, the modular construction allows retrofitting exhaust aftertreatment modules 120, 121, and eases and quickens installation of the same as all components of exhaust aftertreatment modules 120, 121 can be assembled and connected with one another before actually installing modules 120, 121 on hydraulic mining shovel 100.
As used herein, mirror-symmetrical arrangement and configuration is meant to be understood in a generic manner. Specifically, the term refers to a situation in which the parts and units, which are essentially necessary for operation of the respective component or module, are mirrored. Hence, it is intended that features having no key functionality with respect to the desired function of the module do not necessarily have to be mirrored. For example, a substantially mirror-symmetric arrangement and configuration with respect to exhaust aftertreatment modules 120 and 121 specifically means that both modules include substantially equal-constructed reductant tank and pump units 160, 162 and substantially equal-constructed SCR units 156, 158 in a substantially mirrored arrangement with respect to a reference axis.
Although the preferred embodiments of this invention have been described herein, improvements and modifications may be incorporated without departing from the scope of the following claims.
Number | Date | Country | Kind |
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15166177.4 | May 2015 | EP | regional |