A classifier including a housing to take in air flow from below into a radially outer region of an inside space; a flow deflection portion to deflect the air flow toward a center axis of the housing; and an annular rotational portion disposed rotatably in a radially inner region positioned on a radially inner side of the radially outer region, of the inside space of the housing, and configured to classify particles which accompany the air flow. The annular rotational portion includes a plurality of rotational blades arranged at intervals around a rotational axis of the annular rotational portion. The plurality of rotational blades form an outer shape of the annular rotational portion forms an angle θ of not greater than 75° with a segment extended in a horizontal direction from the annular rotational portion outward in a radial direction, in a side view of the annular rotational portion.

A classifier including a housing to take in air flow from below into a radially outer region of an inside space; a flow deflection portion to deflect the air flow toward a center axis of the housing; and an annular rotational portion disposed rotatably in a radially inner region positioned on a radially inner side of the radially outer region, of the inside space of the housing, and configured to classify particles which accompany the air flow. The annular rotational portion includes a plurality of rotational blades arranged at intervals around a rotational axis of the annular rotational portion. The plurality of rotational blades form an outer shape of the annular rotational portion forms an angle θ of not greater than 75° with a segment extended in a horizontal direction from the annular rotational portion outward in a radial direction, in a side view of the annular rotational portion.

A method of upgrading a vertical spindle pulverizer includes the steps of removing a cover from a journal opening in a housing of the pulverizer to access a grinding zone of the pulverizer, removing a first journal assembly having a toroidal grinding roll from the pulverizer through the journal opening, removing a plurality of toroidal table segments from a grinding table of the pulverizer, installing a plurality of inclined bull ring segments on the grinding table, installing a second journal assembly having a conical grinding roll in the pulverizer, and replacing the cover over the journal opening. The inclined bull ring segments are configured to register with a grinding surface of the conical grinding roll.

A grinding device, in particular a vertical mill for grinding a grinding material, the grinding device including at least two grinding elements that are movable relative to one another, wherein the two grinding elements together form at least one grinding portion in which the grinding material is grindable by the two grinding elements; and at least one contact pressure device including at least one hydraulic cylinder including a cylinder operating chamber and at least one gas spring including a spring operating chamber, wherein the cylinder operating chamber and the spring operating chamber are flow connected with one another, wherein a contact force is impartible upon at least one of the grinding elements by the at least one contact pressure device and the grinding elements are pressable onto one another by the contact force.

A grinding device, in particular a vertical mill for grinding a grinding material, the grinding device including at least two grinding elements that are movable relative to one another, wherein the two grinding elements together form at least one grinding portion in which the grinding material is grindable by the two grinding elements; and at least one contact pressure device including at least one hydraulic cylinder including a cylinder operating chamber and at least one gas spring including a spring operating chamber, wherein the cylinder operating chamber and the spring operating chamber are flow connected with one another, wherein a contact force is impartible upon at least one of the grinding elements by the at least one contact pressure device and the grinding elements are pressable onto one another by the contact force.

A system for servicing a pulverizer includes a pulverizer having a housing, a journal assembly pivotally connected to the housing, a grinding mechanism operatively connected to the journal assembly, and an opening within the housing adjacent to the journal assembly and providing an access point to an interior of the housing, and a hoist apparatus mounted to the housing. The hoist apparatus includes a frame assembly received about the opening in the housing, a sheave assembly including a plurality of sheaves supported by the frame assembly, a motor operatively connected to one of the plurality of sheaves, and a cable received by the sheave assembly. The motor is operable to at least one of retract the cable through the sheave assembly to rotate a component out of the pulverizer through the opening and controllably let out the cable to rotate the component into the pulverizer through the opening.

A system for servicing a pulverizer includes a pulverizer having a housing, a journal assembly pivotally connected to the housing, a grinding mechanism operatively connected to the journal assembly, and an opening within the housing adjacent to the journal assembly and providing an access point to an interior of the housing, and a hoist apparatus mounted to the housing. The hoist apparatus includes a frame assembly received about the opening in the housing, a sheave assembly including a plurality of sheaves supported by the frame assembly, a motor operatively connected to one of the plurality of sheaves, and a cable received by the sheave assembly. The motor is operable to at least one of retract the cable through the sheave assembly to rotate a component out of the pulverizer through the opening and controllably let out the cable to rotate the component into the pulverizer through the opening.

A method for grinding feed material (1) in the form of particulate bulk material is disclosed. In the process, particle sizes of the feed material (1) are detected, and the feed material (1) is ground in a mill (3) on the basis of at least one manipulated variable. The at least one manipulated variable is modified when the proportion of small particle sizes in the detected particle sizes increases. A system for grinding feed material (1) in the form of particulate bulk material is also disclosed.

A method for grinding feed material (1) in the form of particulate bulk material is disclosed. In the process, particle sizes of the feed material (1) are detected, and the feed material (1) is ground in a mill (3) on the basis of at least one manipulated variable. The at least one manipulated variable is modified when the proportion of small particle sizes in the detected particle sizes increases. A system for grinding feed material (1) in the form of particulate bulk material is also disclosed.

A system for servicing a pulverizer includes a pulverizer having a housing, a journal assembly pivotally connected to the housing, a grinding mechanism operatively connected to the journal assembly, and an opening within the housing adjacent to the journal assembly and providing an access point to an interior of the housing, and a hoist apparatus mounted to the housing. The hoist apparatus includes a frame assembly received about the opening in the housing, a sheave assembly including a plurality of sheaves supported by the frame assembly, a motor operatively connected to one of the plurality of sheaves, and a cable received by the sheave assembly. The motor is operable to at least one of retract the cable through the sheave assembly to rotate a component out of the pulverizer through the opening and controllably let out the cable to rotate the component into the pulverizer through the opening.