The present invention relates to a method for improving the productivity of grinding plants, wherein, after the optimum wear geometry of the grinding units has been reached by conventional operation of the grinding plant, the optimum wear geometry is preserved by applying a thin wear protection layer to the surface of the grinding units.

The invention relates to a milling bowl, in particular for vertical mills, and to the production of such a milling bowl. Milling bowls of this type have hitherto typically been produced from a cast material as a single piece. Due to the increasing size of said milling bowls, said milling bowls can generally only be transported to the destinations by means of special transport. Therefore, the invention creates a milling bowl consisting of assemblies, wherein a double-walled center part formed from two housing shells is provided between a head flange and a base flange. Said center part forms a cavity, which is filled with a curable casting compound such that a rotationally rigid milling bowl is present after the casting compound has been cured.

A pulverizing device includes: a housing; a pulverization table configured to rotate inside the housing; and a throat, disposed inside the housing on a radially outer side of the pulverization table, for forming an upward air flow. The throat includes: an inner ring extending along an outer periphery of the pulverization table; an outer ring, disposed on a radially outer side of the inner ring so as to form an annular flow passage between the inner ring and the outer ring; and a plurality of throat vanes disposed between the inner ring and the outer ring. The following expressions are satisfied: 2.0≤L/d≤4.0; and 0.5≤H/d≤1.5, where H is a gap between the inner ring and the outer ring with respect to a radial direction, L is a length of the throat vanes, and ‘d’ is a distance between adjacent two of the throat vanes.

A vertical roller mill includes a housing, a chute that supplies materials to be grinded to a center portion of the housing, a grinder that is provided below the chute and grinds the materials to be grinded, an exhaust pipe that is provided above the grinder, a transport mechanism that forms an air flow for transporting, to the exhaust pipe, grinded materials grinded by the grinder, and a flow-constricting flow path provided between the grinder and the exhaust pipe and narrows a flow path area for the air flow, in which the flow-constricting flow path is formed between a first flow-constricting ring provided in the center portion of the housing and a second flow-constricting ring provided to protrude from the housing toward the center portion of the housing.

A system for adjusting a depth of a material bed in a pulverizer mill is provided. The system includes a rotatable bowl, an extension ring, and an extension mechanism. The rotatable bowl has a surface operative to support the material bed while the bowl rotates such that particles of the material bed are pulverized against the surface by one or more grinding rollers of the pulverizer mill. The extension ring is disposed about a circumference of the rotatable bowl extending away from the surface and defines a depth of the material bed. The extension mechanism adjusts at least one of the extension ring and the rotatable bowl while the rotatable bowl rotates. Adjusting at least one of the extension ring and the rotatable bowl via the extension mechanism moves the extension ring in relation to the surface so as to adjust the depth of the material bed.

A mill for crushing a bed of materials by compression includes: a horizontal-axis cylinder the interior wall having a runway track for a crushing roller placed inside the cylinder, a unit rotating the cylinder at a speed that spins the material outward, the crushing roller, a unit for pressing the crushing roller against the runway track of the cylinder, an inlet for supplying material for crushing at one end of the cylinder and an outlet for crushed material at the other end, a unit for controlling the movement of the material so it travels over only a fraction of the length of the cylinder in each revolution and passes between the cylinder and the roller several times before reaching the outlet. The runway track is followed by a downstream lip opposing material flow, downstream of the crushing roller in the direction in which the material travels.

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.

Provided is a roller mill that is provided with: a rotary table; a raw coal adding tube that supplies solid fuel to the rotary table; and a roller that rotates about a rotating shaft by being pressed against a grinding surface of the rotary table and grinds solid fuel along with rotation of the rotary table. In such a roller mill, a position where an outer peripheral surface of the roller and the grinding surface of the rotary table come into contact with each other and a circumferential velocity of the outer peripheral surface equals a circumferential velocity of the grinding surface is located further to an inner circumferential side of the rotary table than a position where the outer peripheral surface and the grinding surface come into contact with each other at a center position in a width direction of the roller.

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.

The invention relates to a pulveriser mill which includes a rotary grinding member and a port ring (10) which is arranged around a periphery of the rotary grinding member for rotation with the rotary grinding member about an axis. The port ring (10) includes a plurality of vanes (22) which are angularly spaced about the axis in a configuration which allows air to flow from below the port ring (10) to above the port ring (10). The vanes (22) are inclined with respect to the vertical and have an operatively upstream end and a downstream end and a non-planar, arcuately curved leading surface (24) which extends between the upstream end and the downstream end. The vanes (22) furthermore have a non-uniform radial width in the axial direction.