HYDRAULIC MINING SHOVEL WITH SCR UNIT

The present disclosure relates to a hydraulic mining shovel. The shovel may comprise a main frame, a power module and a counterweight module. The shovel may further comprise a first exhaust aftertreatment module and a second exhaust aftertreatment module, each being mounted onto the counterweight module and each including a reductant tank and pump unit and a selective catalytic reduction unit. 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 a central longitudinal axis of the main frame.

TECHNICAL FIELD

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.

BACKGROUND

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.

SUMMARY OF THE DISCLOSURE

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.

DETAILED DESCRIPTION

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 shovel100as shown inFIG. 1.

In the shown embodiment ofFIG. 1, hydraulic mining shovel100comprises a superstructure (upper carriage)102, an undercarriage104, and an attachment106with an implement108. A slewing gear device (swing gear device)110is mounted to superstructure102and undercarriage104to enable a relative rotary movement to occur between superstructure102and undercarriage104.

Superstructure102includes a plurality of modules mounted to one another and/or to a main frame112extending longitudinally in a bottom region of superstructure102(inFIG. 1a front end of main frame112is visible only).

The modules include a power module114, a counterweight module116with a counterweight117, an operator cab module118, a first exhaust aftertreatment module120, and a second exhaust aftertreatment module and an oil cooler module (seeFIGS. 2 and 3as both are not visible in the side view ofFIG. 1). Said modules are described in more detail herein under reference toFIGS. 2 to 5.

In a bottom region of power module114, a movable service unit115is provided. Said service unit115may selectively move in direction to ground surface122for providing access to refill inlets and/or control panels for an operator on ground level. During operation, service unit115may be retracted into an accommodation chamber in power module114, for example by means of a hydraulic actuator. In some embodiments, the retraction-and-extension-mechanism for service unit115may be configured to pivot service unit115out of its accommodation chamber.

Further, undercarriage104includes a propulsion device for propelling hydraulic mining shovel100on a work surface122. For example, the propulsion device may include track chains124and drive motors for driving track chains124.

Attachment106includes work implement108such as a face shovel, which is movably mounted to a front end of a stick126that is in turn movably mounted to a boom128. A plurality of hydraulic actuators130allow moving work implement108, stick126and boom128as desired during mining operation.

Turning toFIG. 2for describing an exemplary layout concept of superstructure modules and their components. It is noted that inFIGS. 2 and 3, modules and components are indicated in a schematic manner only. Furthermore, components accommodated inside a respective module are indicated by dashed lines, whereas solid lines indicate a visibility of the component in a top view onto superstructure102assuming that possibly existing covers are demounted.

As noted above and as can be seen inFIG. 2, superstructure102includes main frame112, power module114, counterweight module116, operator cab module118, first and second aftertreatment modules120,121, and oil cooler module132.

Further, main frame112extends along a central longitudinal axis A and supports modules114,116,118and132. In this context it should be noted that main frame112is shown in part only as it is partly overlapped, in particular, by power module114and counterweight module116. Besides mounting structures for attachment106(seeFIG. 1) not shown in detail, main frame112further supports swing drives134and a rotary distributor136for rotating slewing gear device110(seeFIG. 1).

Inside power module114, first and second internal combustion engines138and140are accommodated such that their longitudinal axes (crankshaft axes) B1, B2extend parallel to central longitudinal axis A of main frame112. Additionally, for providing hydraulic power to various components of hydraulic mining shovel100, first and second pump transfer gearboxes142and144are operationally connected to respective outputs of first and second internal combustion engines138and140via respective couplings146,148. For example, engines138and140are configured as diesel engines. Further, as depicted inFIG. 2, a space-saving arrangement may include that first and second internal combustion engines138,140are configured and arranged mirror-symmetrically on opposing sides of power module114with respect to central longitudinal axis A. In other embodiments, for example, first and second internal combustion engines138,140may be configured and arranged merely substantially mirror-symmetrically on opposing sides of power module114with respect to central longitudinal axis A.

Intake air is provided to internal combustion engines138,140by first and second air intake units147and149which are mounted on a top deck150of power module114. Said air intake units147,149are fluidly connected to engines138,140via suitable piping not shown in detail. Additionally, air intake units147and149may be equipped with air filters for cleaning ambient air before supplying the same to engines138,140.

For maintaining stability of hydraulic mining shovel100during operation, counterweight module116includes counterweight117(seeFIG. 1). Counterweight module116is mounted onto main frame112with a clearance to power module114for allowing relative movement between modules116and114such that counterweight module116is decoupled (isolated) against vibrations of power module114, in particular, of first and second internal combustion engines138,140. Additionally, first and second engine coolers152and154including fans for drawing ambient air from the environment are accommodated in counterweight module116for cooling engines138and140, respectively.

On a top deck164of counterweight module116, first and second exhaust aftertreatment modules120and121are mounted. Each exhaust aftertreatment module120,121includes a respective reductant tank and pump unit160,162and a respective selective catalytic reduction (SCR) unit156,158. Further, first and second exhaust aftertreatment modules120,121are configured and arranged mirror-symmetrically at opposing sides of top deck164of counterweight module116with respect to central longitudinal axis A. Additionally, SCR units156,158are mounted closer to central longitudinal axis A than reductant tank and pump units160,162. Alternatively, reductant tank and pump units160,162may be mounted closer to central longitudinal axis A than SCR units156,158. Further, in the shown configuration ofFIG. 2, SCR units156and158are oriented such that their longitudinal axes C1and C2, respectively, extend parallel to central longitudinal axis A of main frame112, whereas reductant tank and pump units160and162are oriented such that their longitudinal axes D1and D2extend perpendicular to central longitudinal axis A.

In some embodiments, first and second exhaust aftertreatment modules120,121may be configured and arranged merely substantially mirror-symmetrically at opposing sides of top deck164of counterweight module116with 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 modules120and121provides a couple of advantages. For example, first and second exhaust aftertreatment modules120and121are substantially isolated against vibrations of internal combustion engines138and140due to the installation onto counterweight module116. Further, first and second exhaust aftertreatment modules120and121are arranged to prevent occurrence of any collisions with material to be excavated and other vehicles. The reason is that modules120and121do not or at least not substantially project beyond counterweight module116in directions of central longitudinal axis A and perpendicular to central longitudinal axis A. Still further, as can be seen in conjunction withFIG. 1, modules120,121and railways (seeFIG. 1) on top decks150and164may function as barriers for increasing safety of operators walking on top decks150and164to prevent that operators may fall down to working surface122. Additionally, the mirror-symmetrical arrangement provides a homogeneous mass distribution acting onto counterweight module116, which further increases the stability of hydraulic mining shovel100and may also allow to reduce a mass of counterweight117(seeFIG. 1) as such a mass reduction may be compensated by exhaust aftertreatment modules120,121.

First reductant tank and pump units160,162may 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 units156or158. By configuring first reductant tank and pump units160,162as 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 shovel100.

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 engines138and140may 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(seeFIG. 1), which is/are fluidly connected to storage chambers of tank and pump units160and162. Said reductant refill inlet(s)166may be provided at movable service unit115. If a reductant refill is required, the operator may lower service unit115in direction to working surface122such that refilling reductant can be performed in a convenient manner from ground level. Additionally or alternatively, tank and pump units160and162may be provided with reductant refill inlets.

Reductant is supplied from first and second tank and pump units160and162to SCR units156and158, respectively, via fluid connections (not shown). Said SCR units156and158include exhaust passages being fluidly connected to exhaust outlets of internal combustion engines138and140, for example, with flexible piping, because of potential relative movements between power module114and counterweight module116. In operation, SCR units156and158inject reductant from tank and pump units160and162into respective exhaust gas streams provided by engines138and140, and passing the exhaust passages of SCR units156and158. The injected reductant together with a suitable catalyzer structure housed in SCR units156and158ensures 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 units156and158to the environment.

Furthermore, operator cab module118may provide an operator seat168and a control panel167for an operator to control hydraulic mining shovel100as desired. For example, control panel167may include joysticks, levers, buttons, and the like for propelling hydraulic mining shovel, and controlling operation of implement108, attachment106, and slewing gear device110. In some embodiments, operator cab module118may 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 module118, for example remote from hydraulic mining shovel100.

Oil cooler module132is provided on an opposite side of mainframe112with respect to operator cab module118. In oil cooler module132, at least one oil cooler170is accommodated.

Referring now toFIG. 3, which shows an arrangement of modules and components of superstructure102′ very similar to the one shown inFIG. 2except that first and second tank and pump units160′ and162′ are oriented in a different manner.

Specifically, in the embodiment shown inFIG. 3, first and second tank and pump units160′ and162′ are oriented such that their respective longitudinal axes D1′ and D2′ are parallel to longitudinal axes A, C1and C2. Again, said arrangement provides the same advantages as the one shown inFIG. 2, for example in terms of collision avoidance, operator safety, space-saving arrangement and configuration, and homogeneous mass distribution.

Referring now toFIGS. 4 and 5for describing exhaust aftertreatment modules120and121in more detail. Specifically, inFIGS. 4 and 5, second aftertreatment module121′ is depicted. However, features described in the following may apply to both exhaust aftertreatment modules120and121if applicable and desired.

As can be seen inFIG. 3, a carrier structure172may be provided to support and fasten both reductant pump and tank unit160′ and SCR unit158. By mounting both units160′ and158onto one carrier, namely carrier structure172, exhaust aftertreatment module121′ can be moved onto counterweight module116and installed thereon as a whole in one single step. For example, carrier structure172may include at least one mounting unit (not shown in further detail) for lifting the same with a crane or the like.

In some embodiments, a common carrier structure may be provided for both exhaust aftertreatment modules120and121. For example, the common carrier structure may be formed as an integral unit, or as two separate carrier structures172fastened to one another. By providing a common carrier structure, first and second exhaust aftertreatment modules may be lifted and/or installed on hydraulic mining shovel100as a whole in one single step.

For allowing a quick installation, retrofit and replacement if required, carrier structure172may further include fastening units for realeasably securing exhaust aftertreatment module121′ onto counterweight module116(seeFIGS. 1 to 3). For example, the fastening means may include bolts, screws or the like.

Furthermore, a drip pan174is disposed below reductant tank and pump unit162′ such that in the event of a leakage, the leaking highly-corrosive reductant can be collected in drip pan174instead of flowing into power module114and/or counterweight module116(seeFIGS. 1 to 3), which may damage components accommodated therein, for example internal combustion engines138,140and engine coolers152and154. For instance, drip pan174may be integrated into carrier structure172.

As the reductant storage chamber of reductant tank and pump unit162′ may store several hundred liters of reductant, a volume of drip pan174may be not sufficient to collect the entire leaking reductant. A drainage mechanism may be included which ensures that in case drip pan174is 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 walls176of drip pan174in a region which would allow reductant to overflow in a direction away from power module114.

Still further, a heat insulation wall178may be arranged between reductant tank and pump unit162′ and SCR unit158to reduce a heat transfer from SCR unit158to reductant tank and pump unit162′. Said heat insulation wall178allows to arrange reductant tank and pump unit162′ and SCR unit158close together although the reductant in the storage chamber of reductant tank and pump unit162′ is very sensitive to heat. For example, heat insulation wall178may include a heat insulating material.

Moreover, heat insulation wall178may be releasably mounted to carrier structure172such 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 module121′ against direct sunlight, debris and oil vapor etc., module121′ may further include a protection cover180covering reductant tank and pump unit162′ and SCR unit158. Protection cover180may include lifting mounts182for moving and installing the same. In some embodiments, protection cover180may cover reductant tank and pump unit162′ or SCR unit158only.

As one skilled in the art will appreciate, application of carrier structure172and its features is not limited to mirror-symmetrical arrangement and configurations of exhaust aftertreatment modules120,121as shown inFIGS. 2 and 3, but may be used in other arrangements and configurations including, for example, other installation positions of the carrier structure on the hydraulic mining shovel, and more or less exhaust aftertreatment modules and internal combustion engines.

INDUSTRIAL APPLICABILITY

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 modules120,121are substantially isolated against vibrations of internal combustion engines138,140due to their arrangement onto counterweight module116. Further, the relatively small overall dimensions of exhaust aftertreatment modules120,121in combination with the non-projecting (or at least not substantially projecting) arrangement onto counterweight module116helps to avoid any collisions with material walls and vehicles. Additionally, the modular construction allows retrofitting exhaust aftertreatment modules120,121, and eases and quickens installation of the same as all components of exhaust aftertreatment modules120,121can be assembled and connected with one another before actually installing modules120,121on hydraulic mining shovel100.

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 modules120and121specifically means that both modules include substantially equal-constructed reductant tank and pump units160,162and substantially equal-constructed SCR units156,158in 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.