The invention relates to a mechanical powder grinder comprising a casing supporting a first rotating grinding member and a second grinding member fixed relative to the casing, each of said first and second members being made of an electrically conductive material. According to the invention, the grinder includes an electrical control circuit providing at least one primary electrical connection between the first and second grinding members, and comprising at least one device for measuring an electrical parameter of said circuit. The grinder further comprises a processing device configured to detect an additional connection between the two grinding members, in particular due to the presence of a foreign body between said members, on the basis of the measured value of said parameter.

A hammer mill grinder includes a feed conveyor, a press wheel and a rotary hammer mill that is enclosed within a mill box. The mill box presents an intake opening for receiving feed material and a discharge opening for discharging reduced material. The press wheel is located adjacent to the mill box intake opening and is mounted at least indirectly to the mill box for vertical movement. The rotary hammer mill presents hammers that rotate, in cyclic succession, past the intake opening, the press wheel, an inside wall and a screen that is offset from the rotary hammer. The inside wall includes a contaminant bypass door that is able to open to allow a contaminant object to bypass the hammer mill prior to the screen and thereby exit the mill box around the screen to prevent damage to the hammer mill grinder.

A hammer mill grinder includes a feed conveyor, a press wheel and a rotary hammer mill that is enclosed within a mill box. The mill box presents an intake opening for receiving feed material and a discharge opening for discharging reduced material. The press wheel is located adjacent to the mill box intake opening and is mounted at least indirectly to the mill box for vertical movement. The rotary hammer mill presents hammers that rotate, in cyclic succession, past the intake opening, the press wheel, an inside wall and a screen that is offset from the rotary hammer. The inside wall includes a contaminant bypass door that is able to open to allow a contaminant object to bypass the hammer mill prior to the screen and thereby exit the mill box around the screen to prevent damage to the hammer mill grinder.

A comminution device can include a crushing body extraction mechanism. The crushing body extraction mechanism can be configured to permit one or more crushing bodies (e.g. rollers of a roller press, etc.) to be continuously moved linearly away from a frame to expose the crushing bodies from the frame. In some embodiments, the extraction mechanism may be configured to utilize one or more rack and pinion mechanisms. The pinion for each such mechanism may be powered by one or more rotary motors or other type of rotary drive mechanism. In other embodiments, the extraction mechanism can include one or more rack and ratchet mechanisms. Each rack and ratchet mechanism may include a hydraulic cylinder or other linear actuator that is extendable and retractable for actuating motion of a ratchet along a rack having columns of differently angled steps to facilitate extension and retraction of one or more crushing bodies.

A comminution device can include a crushing body extraction mechanism. The crushing body extraction mechanism can be configured to permit one or more crushing bodies (e.g. rollers of a roller press, etc.) to be continuously moved linearly away from a frame to expose the crushing bodies from the frame. In some embodiments, the extraction mechanism may be configured to utilize one or more rack and pinion mechanisms. The pinion for each such mechanism may be powered by one or more rotary motors or other type of rotary drive mechanism. In other embodiments, the extraction mechanism can include one or more rack and ratchet mechanisms. Each rack and ratchet mechanism may include a hydraulic cylinder or other linear actuator that is extendable and retractable for actuating motion of a ratchet along a rack having columns of differently angled steps to facilitate extension and retraction of one or more crushing bodies.

A pulverizer has arms connected to a vertically oriented rotating shaft at hubs. The arms are angled relative to radians extending from the shaft to be canted or offset. Pads can be oversized relative to the arms while being one of coplanar with the arms or recessed while possibly also having their radially inward face(s) angled to assist in resisting catching material thereon. A mechanical fuse connection can assist in connecting arms to the hub to prevent dangerous situations as well.

A pulverizer has arms connected to a vertically oriented rotating shaft at hubs. The arms are angled relative to radians extending from the shaft to be canted or offset. Pads can be oversized relative to the arms while being one of coplanar with the arms or recessed while possibly also having their radially inward face(s) angled to assist in resisting catching material thereon. A mechanical fuse connection can assist in connecting arms to the hub to prevent dangerous situations as well.

The invention relates to a device (10; 50) for mechanically comminuting materials, including a vertically extending comminuting chamber (14) having an upwardly extending supply side (15) and a downwardly extending discharge side. The comminuting chamber is enclosed by an in circular cylindrical and/or conical downwardly expanded comminuting chamber wall (12), and in which at least one rotor (16, 18) rotating about a vertical rotor axis (R) is arranged, which is provided with striking tools (38) that extend radially into the comminuting chamber, at least during operation. The rotors(16, 18) are held in a stationary manner with respect to a support base (20) of the device, and the comminuting chamber wall is supported on the support base. According to the invention, the comminuting chamber wall is held in place by way of a lifting device in the direction of the rotor axis (R) in a height adjustable manner relative to the support base (20). The lifting device (36) has a working position, in which the lower edge of the comminuting chamber wall (12) is arranged close to the support base (20) or to a part connected thereto, and a maintenance position, in which the lower edge (32) of the comminuting chamber wall (12) is vertically raised above at least one of the striking tools (22, 24). The invention allows easy maintenance and an uncomplicated exchange of the striking tools of the comminuting device.

The invention relates to a device (10; 50) for mechanically comminuting materials, including a vertically extending comminuting chamber (14) having an upwardly extending supply side (15) and a downwardly extending discharge side. The comminuting chamber is enclosed by an in circular cylindrical and/or conical downwardly expanded comminuting chamber wall (12), and in which at least one rotor (16, 18) rotating about a vertical rotor axis (R) is arranged, which is provided with striking tools (38) that extend radially into the comminuting chamber, at least during operation. The rotors(16, 18) are held in a stationary manner with respect to a support base (20) of the device, and the comminuting chamber wall is supported on the support base. According to the invention, the comminuting chamber wall is held in place by way of a lifting device in the direction of the rotor axis (R) in a height adjustable manner relative to the support base (20). The lifting device (36) has a working position, in which the lower edge of the comminuting chamber wall (12) is arranged close to the support base (20) or to a part connected thereto, and a maintenance position, in which the lower edge (32) of the comminuting chamber wall (12) is vertically raised above at least one of the striking tools (22, 24). The invention allows easy maintenance and an uncomplicated exchange of the striking tools of the comminuting device.

A comminution device can include a crushing body extraction mechanism. The crushing body extraction mechanism can be configured to permit one or more crushing bodies (e.g. rollers of a roller press, etc.) to be continuously moved linearly away from a frame to expose the crushing bodies from the frame. In some embodiments, the extraction mechanism may be configured to utilize one or more rack and pinion mechanisms. The pinion for each such mechanism may be powered by one or more rotary motors or other type of rotary drive mechanism. In other embodiments, the extraction mechanism can include one or more rack and ratchet mechanisms. Each rack and ratchet mechanism may include a hydraulic cylinder or other linear actuator that is extendable and retractable for actuating motion of a ratchet along a rack having columns of differently angled steps to facilitate extension and retraction of one or more crushing bodies.