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 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 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.

In a method and a corresponding device for controlling a rotational speed of a drive driving a shaft, the rotational speed is controlled by a control device which is supplied with a control deviation calculated based on a desired value and an actual value for the rotational speed. The actual value for the rotational speed of the shaft is measured on the shaft with a first sensor and at least one additional sensor and the actual value is calculated from a weighted average of the individual measured values for the rotational speed obtained from the first and the at least one additional sensor.

A crushing mill with a single roller inside a driven cylindrical shell inner surface, both with horizontal and parallel but offset axes is disclosed. In some embodiments, the roller has protrusions such that as the roller and shell rotate rock or other material may be crushed between the shell and the roller, respectively. In some embodiments, the shell and the roller each have surface protrusions such that rock or other materials may be crushed between the shell and the roller as they rotate. In some embodiments the shell and the roller operate at differential speeds with respect to each other to induce shear forces on the material to be crushed.

A crushing mill with a single roller inside a driven cylindrical shell inner surface, both with horizontal and parallel but offset axes is disclosed. In some embodiments, the roller has protrusions such that as the roller and shell rotate rock or other material may be crushed between the shell and the roller, respectively. In some embodiments, the shell and the roller each have surface protrusions such that rock or other materials may be crushed between the shell and the roller as they rotate. In some embodiments the shell and the roller operate at differential speeds with respect to each other to induce shear forces on the material to be crushed.

There is provided an apparatus and method for comminuting a material. The apparatus may comprise a chamber and an inner surface with a plurality of protrusions, and a hammer positioned within said chamber comprising an outer surface having a plurality of second protrusions configured to engage with the first protrusions. The outer and inner surfaces may be separated by a gap distance which defines a comminution zone. The anvil may be rotated to cause a material to be comminuted as the material passes through the comminution zone.

There is provided an apparatus and method for comminuting a material. The apparatus may comprise a chamber and an inner surface with a plurality of protrusions, and a hammer positioned within said chamber comprising an outer surface having a plurality of second protrusions configured to engage with the first protrusions. The outer and inner surfaces may be separated by a gap distance which defines a comminution zone. The anvil may be rotated to cause a material to be comminuted as the material passes through the comminution zone.

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 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.