PIVOTAL DOOR FOR ADJUSTING THE POSITION OF AND GAINING ACCESS TO A GRINDING ROLLER OF A PULVERIZER MILL

1 . A split door assembly for a grinding mill, the split door assembly comprising:

an upper door assembly comprising an upper door exterior surface, the upper door exterior surface being configured to support a journal actuator assembly and the upper door assembly being configured to pivot with a journal having a grinding roller mounted thereon;

a lower door positioned below the upper door assembly; and

a hinge assembly pivotally connected to the upper door assembly and the lower door,

wherein the upper door assembly and the lower door are pivotable together between a closed position and an open position,

wherein when in the closed position, the upper door assembly abuts the lower door, and

wherein when in the open position, the upper door assembly is pivoted away from the grinding mill, the lower door is pivoted away from the grinding mill and the lower door is pivoted relative to the upper door assembly.

2 . The split door assembly of claim 1 , wherein the hinge assembly comprises:

a linkage arm extending from a first pivotal connector to a mounting portion that is secured to the lower door; and

an upper door bracket secured to the upper door assembly and having a second pivotal connector extending outwardly therefrom,

wherein the first pivotal connector is configured to pivot with the second pivotal connector at a pivot axis.

3 . The split door assembly of claim 2 , further comprising a pin extending through the first pivotal connector and the second pivotal connector such that the first pivotal connector is pivotally connected to the second pivotal connector at the pivot axis.

4 . The split door assembly of claim 2 , further comprising:

a shoulder extending from the first pivotal connector; and

a locking plate secured to at least one of the first pivotal connector and the second pivotal connector,

a lateral edge of the locking plate abuts the shoulder, and the locking plate selectively controls a position of the linkage arm relative to the second pivotal connector.

5 . The split door assembly of claim 4 , wherein when the locking plate is removed, the lower door and the bracket are configured to pivot out until a combined center of gravity of the lower door and the bracket is vertically aligned with the pivot axis.

6 . The split door assembly of claim 4 , wherein when the locking plate is removed, a portion of the first pivotal connector is configured to engage the upper door bracket to limit pivoting of the lower door so that the lower door is prevented from engaging a trunnion cylinder secured to the exterior surface of the upper door assembly.

7 . The split door assembly of claim 1 , further comprising:

a journal head pivotally connected to a portion of the grinding mill, the journal head comprising a shaft receiving hub aligned along a longitudinal axis thereof, and a trunnion shaft secured in the hub and projecting outwardly therefrom and into an eccentric trunnion bushing housing, wherein the trunnion bushing housing has a flange extending radially outward from an outboard end thereof, the flange is adjustably secured to the portion of the grinding mill, a trunnion bushing is positioned in the trunnion bushing housing and the shaft is rotatably positioned in the trunnion bushing; and

a lever arm extending between a flange mounting end and a door mounting end thereof, wherein a tab extends upwardly from the lever arm between the flange mounting end and the door mounting end, the flange mounting end is secured to the flange, the door mounting end is secured to the upper door assembly, the lever arm is configured to open and close the upper door assembly and the lower door while the journal head and the grinding roller are secured to the upper door assembly.

8 . The split door assembly of claim 7 , further comprising:

an actuator extending from an upper end to a lower end thereof, the upper end being pivotally connected to a mill wall located at a position above the upper door assembly and the lower end being pivotally connected to the tab; and

the actuator being configured to move the lever arm to open and close the upper door assembly and the lower door.

9 . The split door assembly of claim 7 , further comprising a plurality of first fasteners configured to secure the flange to the portion of the grinding mill, and wherein when the plurality of first fasteners are removed, the trunnion bushing housing is rotatable with respect to the portion of the grinding mill to change a position of the longitudinal axis of the journal head and the grinding roller.

10 . The split door assembly of claim 7 , further comprising a plurality of second fasteners configured to secure the lever arm to the flange, and wherein when the plurality of second fasteners are removed, the lever arm is in rotational sliding engagement with the flange to enable the upper door assembly to pivot towards or away from the mill.

11 . The split door assembly of claim 1 , wherein when the upper door assembly is in a maximum open position, the journal is substantially vertical.

12 . A mill door opening mechanism for a grinding mill, the door opening mechanism comprising:

a door assembly configured to pivot with a journal having a grinding roller in communication therewith,

the door assembly configured to be split into an upper door assembly and a lower door, the upper door assembly pivotal with the journal with the grinding roller mounted thereon;

the journal is fixed to a journal head which is pivotally connected to a portion of the grinding mill,

the journal head comprising a shaft receiving hub aligned along a longitudinal axis thereof,

a trunnion shaft is mounted in the hub and projects outwardly therefrom and into an eccentric trunnion bushing housing, wherein the trunnion bushing housing has a flange extending radially outward from an outboard end thereof, the flange is adjustably secured to the portion of the grinding mill,

a lever arm fixed to the flange; and

an actuator connected between the lever arm and a mill wall of the grinding mill, the actuator is configured to pivot the upper door assembly and the lower door together about the longitudinal axis and between a closed position and an open position.

13 . A grinding roller adjustment mechanism for a grinding mill, the grinding roller adjustment mechanism comprising:

an upper door assembly pivotally arranged to the grinding mill, a journal having a grinding roller mounted thereon, the journal is fixed to a journal head pivotally connected to a portion of the grinding mill,

the journal head comprising a shaft receiving hub aligned along a longitudinal axis thereof, and a trunnion shaft mounted in the hub and projecting outwardly therefrom and into an eccentric trunnion bushing housing, wherein the trunnion bushing housing has a flange extending radially outward from an outboard end thereof, the flange is adjustably secured to the portion of the grinding mill,

a lever arm fixed to the flange; and

an actuator connected between the lever arm and a mill wall of the grinding mill, the actuator is configured to rotate the trunnion bushing housing to thereby change the position of the longitudinal axis while the upper door assembly is closed, to control the location of the grinding roller relative to a grinding ring disposed in the grinding mill.