PULVERIZER WITH OUTPUT FLOW CONTROL AND METHODS FOR CONTROLLING OUTPUT FLOW IN A PULVERIZER

A pulverizer comprising: a housing having top and bottom ends, an inlet located towards the top end for receiving input material to pulverize and an outlet located towards the bottom end for discharging pulverized material from the housing, the housing including a housing sidewall defining an interior chamber and having a central housing axis: a rotatable shaft extending along the central housing axis: a plurality of rotor hub assemblies mounted to the shaft, each rotor hub assembly including a rotor hub and a plurality of rotor arms extending outwardly from the rotor for forming an airflow revolving about the central housing axis within the interior chamber, wherein at least one of the housing and of one or more of the rotor hub assemblies is selectively reconfigurable between a plurality of configurations to adjust at least one parameter of an output flow of the pulverized material at the outlet.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application claims the benefit of Canadian Patent Application No. 3,141,842, filed Dec. 10, 2021, and of Canadian Patent Application No. 3,177,678, filed Sep. 9, 2022, the disclosures of which are incorporated by reference herein in their entirety.

TECHNICAL FIELD

The technical field generally relates to pulverizers and/or vertical mills, and more specifically to pulverizers with one or more features for controlling one or more parameters of an output flow of size-reduced material discharged from the pulverizer. The technical field further pertains to methods for controlling an output flow in a pulverizer.

BACKGROUND

Pulverizing apparatuses, or “pulverizers”, have been used for pulverizing, separating, aerating and/or homogenizing solid materials such as waste material. Pulverizers are sometimes used in certain industrial transformation operations to reduce the particle size of an input material such as ore or the like.

Pulverizers typically include a housing, a rotatable shaft disposed vertically in the housing and one or more rotor assemblies mounted on the rotatable shaft. Material is introduced in the housing through an inlet of the housing, is pulverized by the rotation of the shaft and rotor assemblies, and the pulverized material is discharged through an outlet of the housing. The pulverized material is usually expelled through the outlet by an output flow created by the rotation of the shaft and rotor assemblies.

For various reasons, it may be desirable or necessary to control at least one parameter of the output flow of size-reduced material (e.g. a flowrate or a shape of the output flow) as the size-reduced material is discharged from the pulverizer through an output of the pulverizer. For example, it has been observed that certain configurations of pulverizers create one or more “dead zones” in the output flow in which sized-reduced material is not properly displaced and accumulates on inner surfaces of the housing rather than being properly discharged from the outlet. In some circumstances, it may further be desirable to adjust the flowrate of the output flow based on a type of material being pulverized, or the configuration and/or specifications of a further pulverized material processing stage positioned downstream from the pulverizer, or on any other relevant parameter.

SUMMARY

According to one aspect, there is provided a pulverizer comprising: a housing having top and bottom ends, the housing further having an inlet located towards the top end for receiving input material to pulverize and an outlet located towards the bottom end for discharging pulverized material from the housing, the housing including a housing sidewall extending between the top and bottom ends and defining an interior chamber, the housing having a central housing axis; a rotatable shaft extending between the top end and the bottom end of the housing along the central housing axis; a plurality of rotor hub assemblies mounted to the shaft, each rotor hub assembly including a rotor hub and a plurality of rotor arms extending outwardly from the rotor hub towards the housing sidewall for forming an airflow revolving about the central housing axis within the interior chamber when the rotatable shaft is rotated, wherein at least one of the housing and one or more of the rotor hub assemblies is selectively reconfigurable between a plurality of configurations to adjust at least one parameter of an output flow of the pulverized material at the outlet.

In at least one embodiment, the at least one parameter includes at least one of a flowrate of the output flow and a shape of the output flow.

In at least one embodiment, the plurality of rotor assemblies includes a lower rotor assembly located proximal to the outlet, the lower rotor assembly being reconfigurable between the plurality of configurations.

In at least one embodiment, the rotor arms of the lower rotor assembly are selectively movable between a first position defining a first outer diameter of the lower rotor assembly and a second position defining a second outer diameter of the lower rotor assembly different from the first outer diameter.

In at least one embodiment, each arm includes a rotor connection element and the rotor hub of the lower hub assembly includes a plurality of arm connection elements, the rotor connection element being selectively engageable with one of the arm connection elements for attaching the arm to the rotor hub at a position corresponding to the one of the arm connecting element.

In at least one embodiment, each arm connection element includes a first plurality of fastener-receiving openings and the rotor connection element includes a second plurality of fastener-receiving openings alignable with the first plurality of fastener-receiving openings for receiving arm attachment fasteners therethrough.

In at least one embodiment, the first plurality of fastener-receiving openings includes a plurality of opening sets spaced from each other in a tangential direction and offset from each other in a radial direction.

In at least one embodiment, each opening set includes a plurality of openings aligned in a radial direction on the rotor hub.

In at least one embodiment, each opening set includes two openings.

In at least one embodiment, the rotor hub of the lower rotor assembly has a circular outer edge.

In at least one embodiment, the rotor hub of the lower rotor assembly has a non-circular outer edge.

In at least one embodiment, the rotor hub of the lower rotor assembly is sized and shaped such that the outer edge of the rotor hub is spaced from a tip of the arm by a predetermined distance, the predetermined distance being the same regardless of which opening set is engaged by the arm.

In at least one embodiment, each arm includes an arm body and a wear pad connectable to the arm body.

In at least one embodiment, the arm further includes a plurality of pad connectors disposed along the arm body at a distal end thereof for engaging the wear pad.

In at least one embodiment, each wear pad connector includes a plurality of pad fastener holes and each arm includes a plurality of corresponding arm fastener holes alignable with the pad fastener holes for receiving pad attaching fasteners therethrough.

In at least one embodiment, the wear pad is sized and shaped so as to extend outwardly along the arm up to the arm outer end.

In at least one embodiment, the wear pad is sized and shaped so as to extend outwardly along the arm beyond the arm outer end.

In at least one embodiment, the arm fastener holes include a plurality of fastener hole sets, each fastener hole set corresponding to a position of the wear pad along the arm.

In at least one embodiment, the arm is substantially spaced upwardly from a housing floor and wherein the wear pad is sized and shaped to extend downwardly from the arm and substantially to the housing floor.

In at least one embodiment, each wear pad is asymmetrical.

In at least one embodiment, each wear pad extends along a central pad axis and has upper and lower pad edges extending substantially parallel to the central pad axis, the upper pad edge being spaced from the central pad axis from a first distance and the lower pad edge being spaced from the central pad axis from a second distance greater than the first distance.

In at least one embodiment, each wear pad extends along a central pad axis and has upper and lower pad edges that are substantially linear, at least one of the upper and lower edges being angled relative to the central pad axis.

In at least one embodiment, the upper and lower edges are substantially parallel to each other.

In at least one embodiment, the wear pad is substantially parallelogram-shaped.

In at least one embodiment, the housing includes a discharge portion located at the bottom end thereof, the discharge portion including a discharge portion sidewall defining a discharge chamber portion of the interior chamber, the discharge chamber including a circular chamber portion extending substantially concentrically around the shaft and a discharge conduit extending substantially tangentially to the circular portion to discharge pulverized material from the circular portion, the discharge chamber being configured so as to provide a predetermined shape of the output flow.

In at least one embodiment, the discharge portion sidewall includes a penannular wall portion defining the circular chamber portion and a conduit portion defining the discharge conduit.

In at least one embodiment, the penannular wall portion and the conduit portion meeting at an apex extending towards the shaft, the apex being configured to provide the predetermined shape of the output flow.

In at least one embodiment, the apex is convex and curves inwardly into the interior of the discharge chamber.

In at least one embodiment, the apex includes an apex plate that is removable from the discharge portion sidewall.

In at least one embodiment, the pulverizer further comprises at least one additional apex plate sized and shaped differently from the apex plate, the at least one additional apex plate being interchangeable with the apex plate to provide another predetermined shape to the output flow.

In at least one embodiment, the pulverizer further comprises an apex extension plate connected to a sidewall of the discharge conduit and extending beyond the penannular wall portion and into the discharge chamber to form an apex of the discharge portion within the discharge chamber.

In at least one embodiment, the apex extension plate has a first plate end portion spaced from a straight portion of the discharge portion sidewall to form the discharge conduit and a second plate end portion opposite the first end portion extending beyond the penannular wall portion, the second plate end portion including an inner plate edge.

In at least one embodiment, the inner plate edge is substantially entirely straight.

In at least one embodiment, the inner plate edge includes a vertical segment and a lower angled segment extending forwardly and downwardly from the vertical segment.

In at least one embodiment, the apex extension plate is selectively movable towards and away from the rotatable shaft.

In at least one embodiment, the apex extension plate includes a plurality of plate fastening openings for receiving plate connecting fasteners, the plurality of plate fastening openings including a plurality of plate fastening opening sets, each plate fastening opening set allowing the apex extension plate to extend into the discharge chamber by a predetermined distance.

In at least one embodiment, each fastening opening set includes two fastener openings aligned substantially vertically with each other.

In at least one embodiment, the plurality of plate fastening openings sets includes at least three plate fastening openings sets.

In at least one embodiment, the plurality of plate fastening openings sets includes three plate fastening openings sets.

In at least one embodiment, the second plate end portion is substantially planar.

In at least one embodiment, the second plate end portion is substantially curved.

In at least one embodiment, the first plate end portion is substantially planar and extend in a first plate portion plane, the second plate end curving away from the first plate portion plane.

In at least one embodiment, the second plate end portion is substantially curved away from the discharge conduit.

In at least one embodiment, the second plate end portion is substantially curved towards the discharge conduit.

In at least one embodiment, the housing further includes a flow deviation plate extending away from the discharge portion sidewall and between the rotor hub assemblies and the apex to direct the output flow away from the apex.

According to another aspect, there is also provided a method for adjusting an output flow in a pulverizer, the pulverizer including a rotatable shaft with a plurality of rotor hub assemblies mounted to the shaft, each rotor hub assembly including a rotor hub and a plurality of rotor arms extending outwardly from the rotor hub, the plurality of rotor hub assemblies including a lower rotor assembly located proximal the outlet, the method comprising: adjusting an outer diameter of the lower rotor assembly.

In at least one embodiment, adjusting the outer diameter of the lower rotor assembly comprises moving the rotor arms of the lower rotor assembly relative to the rotor hub of the lower rotor assembly from a first radial position to a second radial position.

In at least one embodiment, moving the rotor arms of the lower rotor assembly comprises: disengaging connectors of the rotor arms from a first set of connectors of the rotor hub; connecting the connectors of the rotor arms to a second set of connectors of the rotor hub.

In at least one embodiment, adjusting the outer diameter of the lower rotor assembly comprises: removing a first wear pad having a first length from each rotor arm of the lower rotor assembly; and securing a second wear pad to each rotor arm of the lower rotor assembly, the second wear pad having a second length different from the first length.

In at least one embodiment, adjusting the outer diameter of the lower rotor assembly comprises: disconnecting a wear pad from a first wear pad connector on each rotor arm of the lower rotor assembly; and connecting the wear pad to a second wear pad connector located at a different position along the corresponding rotor arm of the lower rotor assembly.

According to yet another aspect, there is also provided a method for adjusting an output flow in a pulverizer, the pulverizer including a housing, a rotatable shaft received in the housing and a plurality of rotor hub assemblies mounted to the rotatable shaft, the housing including a discharge portion comprising a penannular wall portion and a conduit portion meeting at an apex extending towards the shaft, the apex includes a first apex plate removably connected to at least one of the penannular wall portion and the conduit portion, the first apex plate being shaped to provide a first output flow shape to the output flow, the method comprising: removing the first apex plate; connecting a second apex plate to at least one of the penannular wall portion and the conduit portion, the second apex plate being shaped to provide a second output flow shape different from the first output flow shape to the output flow.

According to yet another aspect, there is also provided a pulverizer comprising: a housing having an inlet for receiving input material to pulverize and an outlet for discharging pulverized material from the housing; a rotor assembly disposed within the housing for pulverizing the input material and for creating an output flow to expel the pulverized material through the outlet; wherein at least one of the housing and the rotor assembly is reconfigurable to adjust at least one parameter of the output flow at the outlet.

According to yet another aspect, there is also provided a rotor assembly for a pulverizer, the rotor assembly comprising: a rotor hub; and a plurality of rotor arms extending outwardly from the rotor hub, the rotor arms being selectively movable between a first position defining a first outer diameter of the rotor assembly and a second position defining a second outer diameter of the rotor assembly different from the first outer diameter.

In at least one embodiment, each arm includes a rotor connection element and the rotor hub of the lower hub assembly includes a plurality of arm connection elements, the rotor connection element being selectively engageable with one of the arm connection elements for attaching the arm to the rotor hub at a position corresponding to the one of the arm connecting element.

In at least one embodiment, each arm connection element includes a first plurality of fastener-receiving openings and the rotor connection element includes a second plurality of fastener-receiving openings alignable with the first plurality of fastener-receiving openings for receiving arm attachment fasteners therethrough.

In at least one embodiment, the first plurality of fastener-receiving openings includes a plurality of opening sets spaced from each other in a tangential direction and offset from each other in a radial direction.

In at least one embodiment, each opening set includes a plurality of openings aligned in a radial direction on the rotor hub.

In at least one embodiment, each opening set includes two openings.

In at least one embodiment, the rotor hub of the lower rotor assembly has a circular outer edge.

In at least one embodiment, the rotor hub of the lower rotor assembly has a non-circular outer edge.

In at least one embodiment, the rotor hub of the lower rotor assembly is sized and shaped such that the outer edge of the rotor hub is spaced from a tip of the arm by a predetermined distance, the predetermined distance being the same regardless of which opening set is engaged by the arm.

In at least one embodiment, each arm includes an arm body and a wear pad connectable to the arm body.

In at least one embodiment, the arm further includes a plurality of pad connectors disposed along the arm body at a distal end thereof for engaging the wear pad.

In at least one embodiment, each wear pad connector includes a plurality of pad fastener holes and each arm includes a plurality of corresponding arm fastener holes alignable with the pad fastener holes for receiving pad attaching fasteners therethrough.

In at least one embodiment, the wear pad is sized and shaped so as to extend outwardly along the arm up to the arm outer end.

In at least one embodiment, the wear pad is sized and shaped so as to extend outwardly along the arm beyond the arm outer end.

In at least one embodiment, the arm fastener holes include a plurality of fastener hole sets, each fastener hole set corresponding to a position of the wear pad along the arm.

In at least one embodiment, the arm is substantially spaced upwardly from a housing floor and wherein the wear pad is sized and shaped to extend downwardly from the arm and substantially to the housing floor.

In at least one embodiment, each wear pad is asymmetrical.

In at least one embodiment, each wear pad extends along a central pad axis and has upper and lower pad edges extending substantially parallel to the central pad axis, the upper pad edge being spaced from the central pad axis from a first distance and the lower pad edge being spaced from the central pad axis from a second distance greater than the first distance.

In at least one embodiment, each wear pad extends along a central pad axis and has upper and lower pad edges that are substantially linear, at least one of the upper and lower edges being angled relative to the central pad axis.

In at least one embodiment, the upper and lower edges are substantially parallel to each other.

In at least one embodiment, the wear pad is substantially parallelogram-shaped.

DETAILED DESCRIPTION

For the sake of simplicity and clarity, namely so as to not unduly burden the figures with several reference numbers, not all figures contain references to all the components and features, and references to some components and features may be found in only one figure, and components and features of the present disclosure which are illustrated in other figures can be easily inferred therefrom. The embodiments, geometrical configurations, materials mentioned and/or dimensions shown in the figures are optional, and are given for exemplification purposes only.

Moreover, it will be appreciated that positional descriptions such as “above”, “below”, “top”, “bottom”, “forward”, “rearward” “left”, “right” and the like should, unless otherwise indicated, be taken in the context of the figures and correspond to the position and orientation in the pulverizer and corresponding parts when being used. Positional descriptions should not be considered limiting.

Referring now toFIGS.1to4, there is shown a pulverizer10, in accordance with one embodiment. The pulverizer10is adapted to receive an input material and to pulverize or comminute the input material.

It will be understood that the terms “pulverize”, “pulverization”, “comminute” and “comminution” are used herein to refer to a reduction in size of the particles in the input material.

The input material could be completely solid or at least partially solid. Specifically, the input material could include waste, glass, compost, plastic film, rocks, ore, minerals, cement, ceramics, metal pieces or any other material which may be pulverizable.

In the illustrated embodiment, the pulverizer10includes a base12and a housing20mounted over the base12. Specifically, the housing20includes a bottom end22connected to the base12and a top end24opposite the bottom end22. The housing20is hollow and includes a housing sidewall26extending between the top and bottom ends24,22to define an interior chamber28in which the pulverization occurs, as well as a housing floor29, shown inFIG.4, located at the bottom end22. Specifically, the housing20includes an inlet30located at the top end24to receive the input material and an outlet32located at the bottom end22through which the pulverized material may be discharged once having been pulverized in the interior chamber28. In the illustrated embodiment, the outlet32allows pulverized material to be discharged in a substantially tangential direction to the housing sidewall26, as best shown inFIG.4. Still in the illustrated embodiment, the housing sidewall26extends all the way to the bottom end22of the housing20and the outlet32is defined in the housing sidewall26. Alternatively, the housing20could instead include a discharge piece that is distinct from the housing sidewall26and is secured to the housing sidewall26, and the outlet32could be defined in the discharge piece.

As shown inFIG.2, in the illustrated embodiment, the housing20is generally cylindrical and defines a central housing axis H which extends between the top and bottom ends24,22of the housing20and substantially perpendicular to the housing floor29. The housing20is adapted to be disposed such that the central housing axis H extends substantially vertically when the pulverizer10is in operation. In this configuration, the input material fed into the inlet30will ultimately tend to fall down towards the outlet32by gravity.

In the illustrated embodiment, the pulverizer10further comprises a rotor assembly102disposed within the interior chamber28and a rotary actuator104operatively coupled to the rotor assembly102for rotating the rotor assembly102in order to generate an airflow within the housing20. Specifically, the rotor assembly102includes a rotatable shaft106located in the interior chamber28and extending between the top and bottom ends24,22of the housing20, along the central housing axis H, and a plurality of pulverizing rotor assemblies108a,108b,108csecured to the rotatable shaft106so as to rotate about the central housing axis H when the rotatable shaft106is rotated. In the illustrated embodiment, the pulverizing rotor assemblies108a,108b,108cinclude a lower rotor assembly108clocated towards the bottom end22of the housing20, proximal the outlet32, and two upper rotor assemblies108a,108bspaced from each other and located above the lower rotor assembly108c.

Each pulverizing rotor assembly108a,108b,108cincludes a rotor hub120and a plurality of rotor arms122extending outwardly from the rotor hub120and towards the housing sidewall26. Each rotor arm122is elongated and extends between an inner arm end located towards the rotor hub120and an outer arm end or arm tip150extending away from the rotor hub120. The rotatable shaft106extends through the rotor hub120such that the rotor arms122are disposed in an arm rotation plane which extends orthogonally through the central housing axis H. In this configuration, when the rotatable shaft106is rotated, the rotor arms122therefore remain in the arm rotation plane and move along the arm rotation plane. Alternatively, instead of all being disposed in a rotation plane, the rotor arms122could instead be angled upwardly or downwardly relative to the rotatable shaft106. In yet another embodiment, the rotor arms122could instead be pivotably connected to the rotatable shaft106such that the rotor arms122could selectively be angled upwardly and downwardly as desired, either manually or automatically using one or more arm actuators.

The housing20further includes a discharge portion160, located at its bottom end22, in which is defined the outlet32. The discharge portion160has a discharge portion sidewall162which defines a discharge chamber portion164corresponding to a bottom portion of the housing's interior chamber28. The discharge chamber portion164includes a circular chamber portion166defined around the shaft106and a discharge conduit168which extends substantially tangentially to the circular chamber portion166and at the end of which the outlet32is defined. In the illustrated embodiment, the lower rotor assembly108cis disposed in the discharge chamber portion164, and the rotation of the shaft106causes the lower rotor assembly108cto rotate which creates an output flow extending generally circularly around the shaft106and out of the discharge portion160through the discharge conduit168.

For various reasons, it may be desirable to control the output flow of size-reduced material discharged from the pulverizer10. For example, it may be desirable to adjust a flowrate of the output flow according to a configuration of the vessel, receptacle, conduit or transportation device (such as a conveyor or the like) in or on which the size-reduced material is to be discharged, or according to a type of input material being pulverized or to any characteristic of the input material being pulverized. In some circumstances, it has also been observed that the output flow towards the bottom end of the housing and/or in the discharge conduit may adopt a shape which causes size-reduced material to stick to the sidewall of the housing and to accumulate thereon instead of being discharged from the housing. It may therefore be desirable or necessary to modify at least one parameter of flowrate and/or shape of the output flow.

Rotor Outer Diameter Adjustment

Turning toFIG.5, there is shown the lower rotor assembly108cfor the pulverizer10, in accordance with one embodiment.

In this embodiment, the lower rotor assembly108cis configured such that an outer diameter of the lower rotor assembly108ccan be increased in order to increase the flowrate of the output flow or decreased in order to decrease the flowrate of the output flow.

Specifically, the outer diameter of the lower rotor assembly108ccorresponds to a diameter of a circle extending through the arm tips150of the rotor arms122of the lower rotor assembly108c. In this embodiment, to adjust the outer diameter of the lower rotor assembly108c, the arms122may be reconfigured such that the arm tips150may be moved towards or away from the shaft106to thereby respectively decrease or increase the rotor outer diameter. In the illustrated embodiment, this may be accomplished by moving the entire rotor arms122closer to or further away from the shaft106. More specifically, the rotor hub120of the lower rotor assembly108cincludes a plurality of hub connectors200and each arm122of the lower rotor assembly108cincludes an arm connector202(best shown inFIG.7) which is selectively engageable with one of the hub connectors200to position the rotor arm122at a radial position corresponding to a radial position of the hub connector200on the rotor hub120.

In the illustrated embodiment, each rotor arm122includes an arm body210and each arm connector202includes a plurality of fastener-receiving openings220defined in the arm body210. Each hub connector200further includes a corresponding plurality of fastener-receiving openings222which are positioned so as to be alignable with the fastener-receiving openings220of the rotor arms122. The rotor arms122can then be secured to the rotor hub120using fasteners extending through aligned openings of the rotor arms122and the rotor hub120. When connected to the rotor hub120, each rotor arm122overlaps the rotor hub120and includes an outer arm portion226that extends outwardly beyond an outer edge121of the rotor hub120and an inner arm portion228which extends along the rotor hub120and inwardly of the outer edge121of the rotor hub120, towards the shaft106.

In the illustrated embodiment, the rotor hub120of the lower rotor assembly108cincludes an upper hub plate230and a lower hub plate232, and the rotor arms122are substantially sandwiched between the upper and lower hub plates230,232. In this embodiment, the fastener-receiving openings222of the rotor hub120include fastener-openings which face each other such that the rotor arms122may be sandwiched between the upper and lower hub plates230,232, with the fastener-receiving openings220of the rotor arms122aligned with the fastener-receiving openings in both the hub plates230,232. In this position, arm securing fasteners can be inserted through the upper hub plate230, through the rotor arm122and through the lower hub plate232to secure the rotor arm122to the rotor hub120. Alternatively, the rotor hub120may be configured differently. For example, the rotor hub120may not include two hub plates, but could instead includes a single hub body to which the rotor arms122could be attached. Various other hub configurations may also be considered.

As shown inFIG.5, the fastener-receiving openings222defined in the rotor hub120include a plurality of opening sets240a,240b,240c, each opening set including a number of openings corresponding to the number of fastener-receiving openings220in each rotor arm122. Each opening set corresponds to a certain position of the rotor arms122relative to the shaft106and to a certain outer diameter of the lower rotor assembly108c. During operation of the pulverizer10, each rotor arm122is connected to the rotor hub120via one of the opening sets240a,240b,240cwhich provides the lower rotor assembly108cwith a desired outer diameter. Specifically, all the rotor arms122are connected to a same one of the opening sets240a,240b,240cin their corresponding plurality of fastener-receiving openings. For example, the rotor arms122may all be connected to rotor hub120via the first opening set240aof their corresponding plurality of fastener-receiving openings.

To adjust the rotor outer diameter and therefore the flowrate of the outflow, the rotor arms120may be disengaged from the opening set240a,240bor240cthrough which they are connected to the rotor hub102and re-connected to the rotor hub120via a different opening set240a,240bor240cwhich provides the lower rotor assembly108cwith the desired outer diameter creating a desired flowrate of the outflow when the lower rotor assembly108cis rotated. For example, the rotor arms122connected to the first opening set240acould be disconnected from the first opening set240aand be connected to the second or third opening sets240bor240c, which are closer to the shaft106and therefore will reduce the outer diameter of the lower rotor assembly108c, thereby also reducing the flowrate of the output flow.

In the illustrated embodiment, removing the rotor arms122may include removing the fastening pins and removing the upper hub plate230to free the rotor arms122from the rotor hub120. In other embodiments, the lower rotor assembly108ccould instead include an arm repositioning mechanism which could allow the rotor arms122to be repositioned to adjust the outer diameter of the lower rotor assembly108cwithout having to completely remove the fastening pins and/or the upper or lower hub plate. For example, the fastening pins could engage guide slots defined in the hub plates230,232and the rotor arms122could be slidable between the different radial positions corresponding to the opening sets240a,240b,240c. Alternatively, the arm and hub connectors200,202could include other types of connectors instead of fastener-receiving openings and fastening pins.

In the illustrated embodiment, the fastener-receiving openings220of the rotor arms122include two fastener-receiving openings which are spaced apart from each other substantially in a radial direction of the rotor hub120to receive two fastening pins. Similarly, each opening set of the rotor hub120also includes two corresponding fastener-receiving openings spaced apart from each other substantially in the radial direction. The fastening pins thereby create two fixation points of the arms to the rotor hub120to prevent the rotor arm122from pivoting or rotating relative to the rotor hub120. In some embodiments, one of the two fastening pins could be configured as a mechanical fuse and be breakable when the arm is subjected to a force in a substantially tangential direction which is above a certain threshold. This would allow the rotor arm122to pivot about the remaining, unbroken fastening pin to prevent damage to the rotor arm122itself or to the interior of the housing. Alternatively, the two fastening pins may not include a breakable pin.

It will be understood that the term “fastening pin” used hereinabove may refer to any type of elongated fastener that a skilled person would consider suitable, which could be externally threaded or be devoid of any threads, could have a circular, square, triangular cross-section or any other suitable cross-section shape, could have a constant diameter along its length or may have a varying diameter, and/or have any other suitable features.

In the illustrated embodiment, the fastener-receiving openings of the rotor hub120include first, second and third opening sets240a,240b,240cwhich are spaced from each other in a tangential direction and offset relative to each other in a radial direction. Specifically, the opening sets240a,240b,240care positioned such that the opening sets240a,240b,240care positioned progressively closer to the shaft106when moving in a counterclockwise direction around the rotor hub120. Alternatively, the opening sets240a,240b,240ccould be positioned such that the opening sets240a,240b,240care progressively closer to the shaft106when moving in a clockwise direction around the rotor hub120instead, or even be positioned on the hub according to an entirely different configuration.

It will be understood that if the opening sets240a,240b,240cwere all aligned along a single radius of the rotor hub120, creating the openings may necessitate the removal of a relatively large amount of material from the rotor hub120along this radius which may undesirably weaken the rotor hub120along this radius. The present configuration in which the opening sets240a,240b,240care spaced from each other in the tangential direction substantially eliminates this drawback. Nevertheless, in another embodiment, more than one opening set or all opening sets could be aligned with each other along a radius of the rotor hub120.

In the illustrated embodiment, each arm122further includes a wear pad300, best shown inFIG.3, connectable to the arm body210. Specifically, the wear pad300is sized and shaped to cover at least a portion of the arm body210to protect the arm body210from impact of materials fed into the pulverizer10during rotation of the rotor arms122. The wear pad300is therefore positioned on the arm body210so as to face forwardly during rotation of the rotor arm122. More specifically, similarly to a helicopter rotor blade which has a leading edge and a trailing edge, the arm body210has a leading side212and a trailing side214, and the wear pad300is positioned on the leading side212. In other embodiments, the lower rotor's rotation direction could be reversible and each rotor arm122could include wear pads on both sides of the arm body210.

In one embodiment, the wear pad300is sized and shaped to completely cover the outer arm portion226of the rotor arm122. Specifically, the wear pad300extends towards the center of the rotor hub120at least up to the outer edge121of the rotor hub120such that it extends substantially along the entire length of the outer arm portion226.

In the embodiment illustrated inFIG.5, the outer edge121of the rotor hub120is substantially circular. It will be understood that since the opening sets240a,240b,240care positioned progressively closer to the shaft106, when the rotor arms122are moved from one of the opening sets240a,240b,240cto another one of the opening sets240a,240b,240c, the length of the outer arm portion226(i.e. the distance between the arm tip150and the outer edge121of the rotor hub120), is modified accordingly. For example, moving the rotor arms122from attachment via the first opening set240ato attachment via the second opening set240bwill reduce the length of the outer arm portion226. In this embodiment, to allow the outer arm portion226on the leading side212to remain substantially entirely covered when the rotor arm122is moved from the first radial position to the second radial position—or to avoid interference between the wear pad300and the rotor hub120if the outer arm portion226is shorter in the second radial position, the wear pad300could be removed and replaced with another wear pad having a different length corresponding to the length of the outer arm portion226in the second radial position. In this embodiment, the lower rotor assembly108ccould therefore be provided with a plurality of wear pads, each wear pad having a length corresponding to a length of the outer arm portion226of the arms122when the arms122are in a corresponding radial position. Alternatively, the wear pad300may not cover the entire length of the outer arm portion226.

In another embodiment, instead of the arms122including a single set of fastener-receiving openings and the rotor hub120including multiple sets of fastener-receiving openings, the rotor hub120could instead include a single set of fastener-receiving openings for each arm122and each arm122could include multiple set of fastener-receiving openings with each fastener-receiving opening corresponding to a certain radial position of the arm122relative to the rotor hub120. In yet another embodiment, both the arms122and the rotor hub120could include multiple sets of fastener-receiving openings.

FIG.6shows another embodiment of a lower rotor assembly108c′ comprising a rotor hub120′ having an outer edge121′ and a plurality of the rotor arms122connected to the rotor hub120′ such that an outer arm portion226′ of the rotor arms122extend outwardly beyond the outer edge121′ of the rotor hub120′. In this embodiment, the outer edge121′ of the rotor hub120′ is not circular. Instead, the rotor hub120′ is sized and shaped to allow the distance between the arm tips150and the outer edge121′ of the rotor hub120′ to remain constant when the rotor arm122is moved from one radial position to another radial position. In other words, the length of the outer arm portion226′ is the same at every radial position of the arms122. This configuration eliminates the need to provide multiple wear pads having different lengths to allow the outer arm portion226′ to remain substantially entirely covered when the arms122are moved from one position to another position.

Referring now toFIGS.5and8, each wear pad300is substantially elongated and extends between an inner pad end302and an outer pad end304. In the illustrated embodiment, each wear pad300further includes an arm connector306for connecting the wear pad300to a corresponding pad connector307of the rotor arm122. More specifically, the arm connector306includes a pair of fastener-receiving openings308and the pad connector307includes a pair of corresponding pair of fastener-receiving openings310which are spaced from each other similarly to the fastener-receiving openings308of the wear pad300to allow the wear pad300to be connected to the rotor arm122using a pair of fasteners.

In one embodiment, the wear pad300further extends up to an outer end211of the arm body210. In other words, the wear pad does not extend beyond the outer end211of the arm body210. In this embodiment, the wear pad300therefore has a length, corresponding to a distance between the inner and outer pad ends302,304, which is substantially equal to the length of the outer arm portion226.

In some embodiments, the wear pad300could instead extend beyond the outer end211of the arm body210to further increase a surface area of the rotor arm122on the leading side212. In this embodiment, the arm tip150would therefore correspond to the outer pad end304instead of the outer end211of the arm body210.

In one embodiment, the pulverizer10may be provided with a plurality of interchangeable wear pads with different lengths. For example, the plurality of interchangeable wear pads could include a first wear pad300having a first pad length P1, as shown inFIG.8and a second wear pad300′ having a second pad length P2greater than the first pad length P1, as shown inFIG.9. In this embodiment, the first pad length P1could be substantially equal to the length of the outer arm portion226such that the first wear pad300does not extend beyond the outer end211of the arm body210and the second pad length P2could be greater than the length of the outer arm portion226such that the second wear pad300′ extends beyond the outer end211of the arm body210. Alternatively, both the first and second pad lengths P1, P2could be greater than the length of the outer arm portion226such that both the first and second wear pads300,300′ would extend beyond the outer end211of the arm body210.

It will be understood that since in this embodiment, the arm tips150, which define the outer diameter of the lower rotor assembly108c, correspond to the outer pad end304of the wear pad300, replacing the wear pad300on each rotor arm122with a longer wear pad will increase the outer diameter of the lower rotor assembly108c. In this embodiment, instead of moving the rotor arms122to a different radial position to modify the outer diameter of the lower rotor assembly108c, the wear pad300on each rotor arm122could simply be replaced with another wear pad, such as the second wear pad300′ illustrated inFIG.9, which has a different length. In some embodiments, the outer diameter of the lower rotor assembly108ccould be adjusted by a combination of both moving the rotor arm122to a different radial position and by replacing the wear pad with another wear pad having a different length.

Turning toFIG.7, there is shown a rotor arm122′, in accordance with another embodiment. In this embodiment, the rotor arm122′ includes an arm body210′ having an outer end211′ and a plurality of pad connectors307′, each pad connector307′ corresponding to a different position of the wear pad300along the arm122′. Specifically, in the illustrated embodiment, the plurality of pad connectors307′ comprises first, second and third pad connectors307a,307b,307c. The pad connectors307′ are substantially aligned with each other along a longitudinal arm axis A1of the arm122and each pad connector including a pair of fastener-receiving openings. Alternatively, the arm body210′ could include more or less than three pad connectors.

In this embodiment, instead of replacing the wear pad300with another wear pad having a different length, the wear pad300could simply be connected to the arm body210′ using another one of the pad connectors307′. For example, by moving the wear pad300from the first pad connector307ato the second pad connector307blocated further towards the outer end211′ of the arm body210′, the outer pad end304moves further away from the hub120, thereby increasing the outer diameter of the lower rotor assembly108c. Conversely, by moving the wear pad300from the second pad connector307bto the first pad connector307awould move the outer pad end304towards the hub120and thereby reduce the outer diameter of the lower rotor assembly108c.

In another embodiment, instead of the arm122comprising multiple pad connectors307′, the arm122could include a single pad connector by the wear pad300could include multiple arm connectors306spaced from each other along a longitudinal pad axis PA of the wear pad300and which could be selectively connected to the pad connector to secure the wear pad300to the arm122at a desired radial position. In yet another embodiment, the outer diameter of the lower rotor assembly108ccould be adjusted both by replacing the wear pad300by another wear pad having a different length and by connecting the other wear pad at a different position along the arm body210′.

In other embodiments, the arms122could be configured differently such that moving the arm tips150towards and away from the shaft106does not involve moving the entire arms122. For example, in one embodiment, the arms122could be telescopic such that the arm tips150can be moved relative to an inner end of the arm.

In yet another embodiment, instead of only the lower rotor assembly108cbeing adjustable, one or more of the other rotor assemblies108a,108bcould also be configured according to one or more of the above-described configurations to allow its diameter to be adjusted.

Wear Pad Geometry

It will be understood that the wear pads300, being placed on the leading side212of the arm body210, may contribute to the generation of the output flow, and could further have a geometry selected to provide an output flow having one or more desired characteristics.

For example, in the embodiment illustrated inFIGS.8and9, the wear pads300are further configured so as to contribute to the generation of airflow within the pulverizer10. More specifically, the wear pad300may extend at least partially upwardly beyond a top side216of the arm body210and/or downwardly beyond a bottom side218of the arm body210to increase the surface area of the rotor arm122on the leading side212. In the embodiment illustrated inFIG.8, the wear pad300includes an inner pad portion320located towards the inner pad end302which has a height corresponding substantially to a height of the arm body210, and an outer pad portion322located towards the outer pad end304which has a height greater than the height of the inner pad portion320, and therefore greater than the height of the arm body210. More specifically, in the illustrated embodiment, the outer pad portion322extends both upwardly beyond the top side216and downwardly beyond the bottom side218of the arm body210. Alternatively, the outer pad portion322could instead only upwardly beyond the top side216or only downwardly beyond the bottom side218.

In one embodiment, the wear pad300may be sized and shaped to extend only along the outer arm portion226of the arm body210, which extends outwardly beyond the outer edge121of the rotor hub120. In this embodiment, the inner pad end302is generally aligned with the outer edge121of the rotor hub120.

Alternatively, the wear pad300may be sized and shaped to extend along the outer arm portion226and partially on the inner arm portion228of the arm body210. For example, the wear pad300may be sized and shaped such that the outer pad portion322extends along the outer arm portion226and the inner pad portion320extends along a portion of the inner arm portion228.

Turning toFIG.10, there is shown a wear pad400, in accordance with another embodiment. In this embodiment, the wear pad400is generally elongated and extends along a central pad axis PA. The wear pad400includes inner and outer pad ends402,404and upper and lower edges406,408extending between the inner and outer pad ends402,404.

In the embodiment illustrated inFIG.10, the upper edge406includes a first upper edge segment410located towards the inner pad end302and a second upper edge segment412located towards the outer pad end404. The first and second edge segments410,412are substantially parallel to each other and to the central pad axis PA but are spaced from the central pad axis PA by different distances. Specifically, the first upper edge segment410is spaced from the central pad axis PA by a first upper segment distance and the second edge segment412is spaced from the central pad axis PA by a second upper segment distance greater than the first upper segment distance. The first and second upper edge segments410,412are further connected to each other by a third upper edge segment414which extends substantially perpendicularly to the first and second upper edge segments410,412. In the illustrated embodiment, the first upper edge segment410further has a first upper segment length UL1and the second upper edge segment412has a second upper segment length UL2which is greater than the first upper segment length UL1.

Still in this embodiment, the lower edge408includes a first lower edge segment416located towards the inner pad end302and a second lower edge segment418located towards the outer pad end304. The first and lower edge segments416,418extend substantially parallel to each other and to the central pad axis PA. Similarly to the first and second upper edge segments410,412, the first and second lower edge segments416,418are not aligned with each other but are instead spaced from the central pad axis PA by different distances. Specifically, the first lower edge segment416is spaced from the central pad axis PA by a first lower segment distance and the second lower edge segment418is spaced from the central pad axis PA by a second lower segment distance which is greater than the first distance. In the illustrated embodiment, the wear pad400is asymmetrical about the central pad axis PA. Specifically, while the first lower segment distance is substantially similar to the first upper segment distance, the second lower segment distance is substantially greater than the second upper edge distance. The first and second lower edge segments416,418are further connected together by a third lower edge segment420which extends substantially perpendicularly to the first and second lower edge segments416,418.

In one embodiment, the lower rotor assembly108cis positioned towards the bottom end22of the housing20, but at least slightly vertically higher than the housing floor29such that the rotor arms122of the lower rotor assembly108care spaced upwardly from the housing floor29. In this embodiment, the wear pad400may be shaped such that the second lower segment distance is substantially equal to the distance between the central pad axis PA and the housing floor29to close the gap between the wear pad400and the housing floor29. In this embodiment, the second lower edge segment418can therefore be slightly spaced from the housing floor29but almost contact the housing floor29.

In the embodiment illustrated inFIG.10, the first lower edge segment416further has a first lower segment length LL1and the second lower edge segment418has a second lower segment length LL2. In this case, the first lower segment length LL1is greater than the second lower segment length LL2. Moreover, the second upper segment length UL2is substantially greater than the second lower segment length LL2.

Referring now toFIG.11, there is shown a wear pad400′, in accordance with another embodiment. In this embodiment, the wear pad400′ is generally elongated and extends along a central pad axis PA. The wear pad400′ includes inner and outer pad ends402′,404′ and upper and lower edges406′,408′ extending between the inner and outer pad ends402′,404′. The upper edge406′ includes first and second upper edge segments410′,412′ and the lower edge408′ includes first and second lower edge segments416′,418′. The first upper edge segment410′ is spaced from the central pad axis PA by a first upper segment distance and the second upper edge segment412′ is spaced from the central pad axis PA by a second upper segment distance which is greater than the first upper segment distance. The first and second upper edge segments410′,412′ are further connected together by a third upper edge segment414′ extending substantially perpendicularly to the first and second upper edge segments410′,412′.

The first lower edge segment416′ is further spaced from the central pad axis PA by a first lower segment distance and the second lower edge segment418′ is spaced from the central pad axis PA by a second lower segment distance which is substantially greater than the first lower segment distance. Specifically, the second lower segment distance is substantially greater than the second upper segment distance such that the wear pad400′ is asymmetrical about the central pad axis PA. In the illustrated embodiment, the second lower segment distance of the wear pad400′ is further substantially greater than the second lower segment distance of the wear pad400illustrated inFIG.10. The first and second lower edge segments416′,418′ are further connected together by a third lower edge segment420′ extending substantially perpendicularly to the first and second lower edge segments416′,418′.

Similarly to the wear pad400illustrated inFIG.10, the first upper edge segment410′ has a first upper segment length UL1′, the second upper edge segment412′ has a second upper segment length UL2′, the first lower edge segment416′ has a first lower segment length LL1′ and the second lower edge segment418′ has a second lower segment length LL2′. In the embodiment illustrated inFIG.11, the first upper segment length UL1′ and the first lower segment length LL1′ are substantially equal to each other, and the second upper segment length UL2′ and the second lower segment length LL2′ are substantially equal to each other. The third upper edge segment414′ and the third upper edge segment420′ are therefore substantially aligned with each other. The second upper segment length UL2′ and the second lower segment length LL2′ are further substantially greater than the first upper segment length UL1′ and the first lower segment length LL1′.

It will be understood that the above configurations of the wear pads400,400′ are provided merely as an example and that various other configurations may be considered.

Referring now toFIGS.12and13, there is shown a wear pad450, in accordance with another embodiment. In this embodiment, the wear pad450is generally elongated and extends along a central pad axis PA. The wear pad450includes inner and outer pad ends452,454and upper and lower edges456,458extending between the inner and outer pad ends452,454. In this embodiment, the upper and lower edges456,458each include a single continuous and straight segment extending between the inner and outer pad ends452,454. In this embodiment, the wear pad450includes an arm connector460cooperable with a corresponding pad connector of the rotor arm122to secure the wear pad450to the arm122. Specifically, the arm connector460includes a pair of fastener-receiving openings462which are spaced from each other and are both disposed on the central pad axis PA.

Still in this embodiment, the upper and lower edges456,458extend substantially parallel to each other. However, the upper and lower edges456,458do not extend parallel to the central pad axis PA but are instead angled relative to the central pad axis PA, such that the wear pad450is substantially parallelogram-shaped.

In one embodiment, the upper edge456extends away from the central pad axis PA as it extends from the inner pad end452to the outer pad end454, and the lower edge458extends towards the central pad axis PA as it extends from the inner pad end452to the outer pad end454. Alternatively, the upper edge456could instead extend towards the central pad axis PA and the lower edge458could extend away from the central pad axis PA as they extend from the inner pad end452to the outer pad end454.

As shown inFIG.12, in the illustrated embodiment, the wear pad450is substantially flat and includes front and rear planar faces470,472that extend substantially parallel to each other. Alternatively, the front and rear planar faces470,472could instead be angled relative to each other, or the front and rear planar faces470,472could instead not be planar and could instead have any other suitable configuration.

In one embodiment, the wear pad450is further reversible, either to extend its life or to change one or more parameters of the output flow. In other words, the wear pad450could be secured to the corresponding rotor arm122in a first orientation, unsecured from the corresponding rotor arm122and secured again to the corresponding rotor arm122in a second orientation different from the first orientation. For example, the wear pad450could be reversed about the central pad axis PA such that the lower edge458extend above the upper edge456, or reversed about an axis R perpendicular to the central pad axis PA such that the inner and outer pad ends452,454are interchanged. The wear pad450could also be fully reversed by flipping it both about the central pad axis PA and the axis R.

Discharge Portion Configuration

The output flow could also be controlled by configuring the discharge portion160of the housing20in an appropriate configuration. In some embodiments, the discharge portion160or at least part of the discharge portion160could further be reconfigurable in one of multiple configurations, each configuration providing the output flow with one or more desired characteristics.

Referring back toFIG.4, the discharge portion sidewall162includes a penannular wall portion170defining the circular chamber portion166and a conduit portion172defining the discharge conduit168. Specifically, the penannular wall portion170includes a first penannular wall end174, a second penannular wall end176and a curved wall178extending therebetween. The conduit portion172includes outer and inner planar walls180,182extending parallel to each other. The outer planar wall180extends from the first penannular wall end174and the inner planar wall182extending from the second penannular wall end176. While the outer planar wall180meets the curved wall178and forms a substantially smooth transition therewith, the inner planar wall182may meet the curved wall178at a substantially sharp angle forming an apex184of the discharge portion sidewall162, located adjacent the discharge conduit168.

It has been observed that a so-called “dead zone” in the output flow may be created on or around the apex184, which causes pulverized material to remain stuck on the apex184and/or on the curved wall178near the apex184instead of being properly discharged through the discharge conduit168. By modifying the configuration of the apex184, this dead zone may be reduced or even eliminated to thereby minimize the amount of pulverized material accumulating on the interior of the discharge portion sidewall162, on the walls172,180and/or on the floor32.

Referring now toFIGS.14and15, there is shown a discharge portion160′, in accordance with one embodiment. In this embodiment, the discharge portion160′ includes the outer and inner planar walls180,182defining the discharge conduit168and the curved wall178defining the circular chamber portion166. The inner planar wall182meets the curved wall178to form an apex184′. In this embodiment, the apex184′ is curved, and more specifically convexly curved, instead of forming a substantially sharp angle. It has been observed that providing a convexly curved apex reduces the amount of pulverized material that accumulates on the interior of the discharge portion sidewall162.

In the illustrated embodiment, the apex184′ is formed by a curved apex plate186which extends between the curved wall178and the inner planar wall182and which creates a smooth, substantially continuous transition between curved wall178and the inner planar wall182. Alternatively, the apex184′ could be formed using any other suitable configuration.

FIG.16shows a discharge portion160″, in accordance with another embodiment. In this embodiment, the discharge portion160″ includes an apex184″ formed by an apex plate186″ which is removable from the discharge portion sidewall162. In one embodiment, the pulverizer10could be provided with one or more additional apex plates which are sized and shaped differently from the apex plate186″ (e.g. convexly curved at different radiuses, planar but slanted at different angles, etc.) and which could be interchanged with the apex plate186″ to provide other characteristics to the output flow.

Turning toFIGS.17and18, there is shown a discharge portion500, in accordance with another embodiment. In this embodiment, the discharge portion500includes the outer and inner planar walls180,182defining the discharge conduit168and the curved wall178defining the circular chamber portion166. In this embodiment, the discharge portion500further includes an apex extension plate502which extends substantially parallel to the inner planar wall182and which is secured to the inner planar wall182. The apex extension plate502has a first plate end portion504which extends along the inner planar wall182and a second plate end portion506, located opposite the first plate end portion504, which extends beyond the curved wall178. In the embodiment illustrated inFIGS.17and18, the apex extension plate502is substantially rectangular and includes an inner plate edge508, an outer plate edge510and top and bottom plate edges512,514extending between the inner and outer plate edges508,510. In this embodiment, the inner plate edge508is substantially linear and extends substantially parallel to the outer plate edge510, while the top and bottom plate edges512,514extend substantially parallel to each other and substantially perpendicular to the inner and outer plate edges508,510.

When the apex extension plate502is secured to the inner planar wall182, the inner plate edge508is located towards the lower rotor assembly108cand extends substantially vertically and substantially perpendicular to the housing floor29, while the bottom plate edge514extends along the housing floor29. In this configuration, the inner plate edge508defines an apex516of the discharge portion500.

The apex extension plate502further includes a plurality of plate connectors516for connecting the apex extension plate502to the inner planar wall182. Specifically, in the illustrated embodiment, each plate connector516includes a pair of plate connection openings518for receiving fasteners. The connection openings518can be placed in alignment with corresponding connection openings on the inner planar wall182and the fasteners can be inserted into the connections opening518of the apex extension plate502and of the inner planar wall182to thereby secure the apex extension plate502to the inner planar wall182.

In the illustrated embodiment, the connectors516are spaced from each other in a longitudinal direction relative to the apex extension plate502. Each connector corresponds to a position of the apex extension plate502relative to the inner planar wall182. This allows the distance between the inner plate edge508and the lower rotor assembly18cto be adjusted by connecting the apex extension plate502via a corresponding one of the plate connectors516. Alternatively, the apex extension plate502may not include multiple connectors516and/or may not be movable.

FIG.19shows an apex extension plate550in accordance with another embodiment. In this embodiment, the apex extension plate550includes an inner plate edge552which is not fully straight, but instead includes a central vertical segment554, an upper angled segment556extending upwardly and forwardly from the central straight portion554and a lower angled segment558extending downwardly and forwardly from the central straight portion554.

FIG.20shows an apex extension plate550′, in accordance with yet another embodiment. In this embodiment, the apex extension plate550includes an inner plate edge552′ which has an upper vertical segment554′ and a lower angled segment558′.

Both the plates550and550′ are configured such that when secured to the inner planar wall182, the rotors arms122and wear pads300are horizontally aligned with a respective one of the central vertical segment554and the upper vertical segment554′ and the lower angled segment558,558′ extends below the rotors arms122and wear pads300.

Referring now toFIGS.21and22, the apex extension plate may not be fully planar. More specifically,FIG.21shows an apex extension plate600which is substantially curved away from the discharge conduit168whileFIG.22shows an apex extension plate650which is substantially curved towards the discharge conduit168. Specifically, the first plate end portion504of the plates600,650is still planar, while the second plate end portion506of the plates600,650, which extends beyond the curved wall178, is curved. These configurations may further contribute to reduce the accumulation of pulverized material on the interior of the discharge portion sidewall162.

Additional features and elements could also be provided within the housing20to allow the shape of the output flow to be adjusted. The additional features and elements could be provided alone or in combination with any of the features related to the lower rotor assembly, to the configuration of the wear pads and/or to the configuration of the discharge portion160as described above.

Referring toFIG.23, in one embodiment, the housing20further includes a flow guiding member700disposed in the discharge portion160to provide a desired shape of the output flow. Specifically, the flow guiding member700includes a flow deviation plate702which is secured to the penannular wall portion170. In the illustrated embodiment, the flow deviation plate702is substantially curved and extends between a first deviation plate end704and a second deviation plate end706. The first deviation plate end704is connected to the penannular wall portion170and the flow deviation plate702extends along the penannular wall portion170towards the apex184while deviating increasingly towards the center of the circular chamber portion166. The second deviation plate end706is located further towards the discharge conduit168, beyond the apex184, such that the flow deviation plate702extends between the apex184and the lower rotor assembly108cto direct the output flow away from the apex184.

In another embodiment, the flow deviation plate702could be substantially longer and the first deviation plate end704could be positioned further away from the discharge conduit168to allow the flow deviation plate702to guide the output flow along a longer deviation path away from the apex184.

In other embodiments, the housing20could include multiple flow deviation plates substantially similar to the flow deviation plate702, which could be disposed at predetermined locations inside the discharge portion160to further guide the output flow along a desired path inside the discharge portion160. In yet another embodiment, the flow deviation plate702may not be curved but could instead be planar or have any other suitable shape, size or configuration. In yet another embodiment, the flow guiding member700may not include a plate and could instead be configured according to any other suitable configuration.

It will be understood that the pulverizer could include any combination of two or more of the features described above to control one or more parameters of the output flow, such as the shape and the flowrate of the output flow.

By allowing the control of the output flow and/or the adjustment of one or more parameters of the output flow, the above features reduce the amount of pulverized material which remains stuck to the interior of the discharge portion160, the walls172,180and/or the floor32of the housing20. This reduces the costs and labor associated with the maintenance of the pulverizer and ensures that the pulverizer10operates optimally.

These features further increase the amount of pulverized material that is expelled through the outlet and can be further treated and/or repurposed, thereby increasing the overall yield of the pulverizer by reducing or eliminating waste.