Discharge grates for reduction mills

1. A discharge grate component for use in a reduction machine, the discharge grate component comprising:

intersecting members engaging each other to define a common interior working surface with discharge openings, and

at least one stop extending outward the common interior working surface and from one of the intersecting members such that a substantial portion of the at least one said stop extends upstream to limit straight line paths of material through at least some of the discharge openings.

2. A discharge grate component in accordance with claim 1 wherein the at least one said stop extends outward of the discharge openings in at least partially a curved configuration.

3. A discharge grate component in accordance with claim 1 wherein the intersecting members include at least one longitudinal grate element and a plurality of transverse grate elements to form the discharge openings through the grate component, and wherein the at least one stop defines at least one longitudinal support beam to resist bending and deflection of the overall discharge grate component.

4. A discharge grate component in accordance with claim 1 wherein the at least one said stop has an upstream surface with a concave curvature in a direction opposite a direction of material flow over an interior working surface.

5. A discharge grate component in accordance with claim 1 wherein the discharge grate component has at least one longitudinal support beam to resist bending and deflection of the overall discharge grate component.

6. A discharge grate component is accordance with claim 3 wherein the discharge openings define at least a portion of the at least one said stop.

7. A discharge grate component in accordance with claim 1 wherein the at least one said stop is generally continuously curved as it extends away from the discharge openings.

8. A discharge grate component for use in a reduction machine, the discharge grate component comprising:

intersecting members to define an interior surface and discharge openings, and

at least one stop extending outward of the discharge openings and at least partially curved in a direction opposite a direction of material flow over the interior surface to limit straight line paths of material through at least some of the discharge openings.

9. A discharge grate component in accordance with claim 8 wherein the intersecting members include at least one longitudinal grate element and a plurality of transverse grate elements to form the discharge openings through the grate component, and wherein the at least one stop defines at least one longitudinal support beam to resist bending and deflection of the overall discharge grate component.

10. A discharge grate component in accordance with claim 8 wherein the at least one stop is oriented so that there is generally no straight line of path through the discharge openings.

11. A discharge grate component in accordance with claim 8 wherein the at least one said stop has an upstream surface that has a concave curvature in a direction opposite a direction of material flow over the interior surface.

12. A discharge grate component in accordance with claim 8 wherein the discharge grate component has at least one longitudinal support beam to resist bending and deflection of the overall discharge grate component.

13. A discharge grate component is accordance with claim 9 wherein the discharge openings define at least a portion of the at least one said stop.

14. A discharge grate component in accordance with claim 8 wherein the at least one said stop is generally continuously curved as it extends away from the discharge openings.

15. A discharge grate component for use in a reduction machine, the discharge grate component comprising:

at least one longitudinal grate element,

a plurality of transverse grate elements intersecting the at least one said longitudinal grate element to define discharge openings through the grate component, the at least one said longitudinal grate element and the plurality of transverse grate elements having an interior working surface defining a wear surface across which material to be reduced traverses, and

at least one stop outward of the interior working surface such that there is generally no straight line of path through the discharge openings.

16. A discharge grate component in accordance with claim 15 wherein the at least one said stop extends outward of the discharge openings and has an upstream surface that is arcuate as the upstream surface extends away from the discharge openings such that the upstream surface curves in a direction opposite a direction of material flow over the interior working surface.

17. A discharge grate component in accordance with claim 15 wherein the discharge grate component has at least one longitudinal support beam to resist bending and deflection of the overall discharge grate component.

18. A discharge grate component is accordance with claim 15 wherein the discharge openings define at least a portion of the at least one said stop.

19. A discharge grate component in accordance with claim 15 wherein the at least one said stop is generally continuously curved as it extends away from the discharge openings.

20. A discharge grate component for use in a reduction machine, the discharge grate component comprising

at least one longitudinal grate element,

a plurality of transverse grate elements intersecting the at least one said longitudinal grate element to define discharge openings through the grate component, the at least one said longitudinal grate element and the plurality of transverse grate elements having an interior working surface defining a wear surface across which material to be reduced traverses, and

at least one stop extending outward of the discharge openings and having an upstream surface that is arcuate as the upstream surface extends away from the discharge openings such that the upstream surface curves in a direction opposite a direction of material flow over the interior working surface.

21. A discharge grate component in accordance with claim 20 wherein the discharge grate component has at least one longitudinal support beam to resist bending and deflection of the overall discharge grate component.

22. A discharge grate component in accordance with claim 20 wherein the discharge grate component has at least one longitudinal support beam to resist bending and deflection of the overall discharge grate component, and the at least one longitudinal support beam is secured to the at least one said longitudinal grate element.

23. A discharge grate component in accordance with claim 20 wherein the discharge grate component has at least one longitudinal support beam to resist bending and deflection of the overall discharge grate component, and the at least one said longitudinal support beam is secured to a portion of each of the plurality of transverse grate elements.

24. A discharge grate component in accordance with claim 22 wherein the at least one said longitudinal support beam defines at least a portion of the at least one said stop.

25. A discharge grate component in accordance with claim 20 wherein the at least one said stop is an integral part of the at least one said longitudinal grate element.

26. A discharge grate component in accordance with claim 22 wherein the at least one said stop is an integral part of the at least one said longitudinal grate element and the at least one said longitudinal support beam.

27. A discharge grate component in accordance with claim 22 wherein the at least one said longitudinal support beam extends forward of a leading edge of the interior working surface of the discharge grate component.

28. A discharge grate component is accordance with claim 20 wherein the discharge openings define at least a portion of the at least one said stop.

29. A discharge grate component in accordance with claim 20 wherein the at least one said stop is generally continuously curved as it extends away from the discharge openings.

30. A discharge grate component in accordance with claim 20 wherein the discharge openings have a width in the direction of the material flow over the grate, and the at least one said stop has a depth that it extends outward of the discharge openings, wherein the width of the discharge openings to the depth of the at least one said stop has a ratio of less than 0.95.

31. A discharge grate component in accordance with claim 30 wherein the width to depth ratio is less than or equal to 0.6.

32. A material reducing machine, the material reducing machine comprising,

a reducing chamber;

a material inlet system for feeding material into the reducing chamber;

a rotary head having a drive shaft and hammers to reduce the material fed into the reducing chamber; and

a grate structure, the grate structure comprising

at least one discharge grate component, the discharge grate component comprising intersecting members engaging each other to define a common interior working surface with discharge openings, and

at least one stop outward of the common interior working surface and the discharge openings along one of the intersecting members such that a substantial portion of the at least one said stop extends upstream from the one intersecting member to limit the length of material through at least some of the discharge openings.

33. A material reducing machine, the material reducing machine comprising,

a reducing chamber;

a material inlet system for feeding material into the reducing chamber;

a rotary head having a drive shaft and hammers to reduce the material fed into the reducing chamber; and

a grate structure, the grate structure comprising

at least one discharge grate component, the discharge grate component comprising intersecting members to define discharge openings, and at least one support beam to resist bending and deflection of the overall discharge grate component, wherein the at least one support beam extends outward of the discharge openings and is at least partially curved over at least some of the discharge openings to limit the length of material therethrough.

34. A material reducing machine, the material reducing machine comprising,

a reducing chamber;

a material inlet system for feeding material into the reducing chamber;

a rotary head having a drive shaft and hammers to reduce the material fed into the reducing chamber; and

a grate structure, the grate structure comprising at least one discharge grate component, the discharge grate component comprising at least one longitudinal grate element, a plurality of transverse grate elements intersecting the at least one said longitudinal grate element to define discharge openings through the grate component, the at least one said longitudinal grate element and the plurality of transverse grate elements having an interior working surface defining a wear surface across which material to be reduced traverses, and at least one stop outward of the wear surface such that there is generally no straight line of path through the discharge openings.

35. A material reducing machine, the material reducing machine comprising,

a reducing chamber;

a material inlet system for feeding material into the reducing chamber;

a rotary head having a drive shaft and hammers to reduce the material fed into the reducing chamber; and

a grate structure, the grate structure comprising at least one discharge grate component, the discharge grate component comprising at least one longitudinal grate element, a plurality of transverse grate elements intersecting the at least one said longitudinal grate element to define discharge openings through the grate component, the at least one said longitudinal grate element and the plurality of transverse grate elements having an interior working surface defining a wear surface across which material to be reduced traverses, and at least one stop extending outward of the discharge openings and having an upstream surface that is arcuate as the upstream surface extends away from the discharge openings such that the upstream surface curves in a direction opposite a direction of material flow over the interior working surface.

36. A material reducing machine, the material reducing machine comprising,

a reducing chamber;

a material inlet system for feeding material into the reducing chamber;

a rotary head having a drive shaft and hammers to reduce the material fed into the reducing chamber, the rotary head having a rotational axis about which it rotates; and

a grate structure, the grate structure comprising a plurality of discharge grate components, each said discharge grate component comprising at least one longitudinal grate element, a plurality of transverse grate elements intersecting the at least one said longitudinal grate element to define discharge openings through the grate component, the at least one said longitudinal grate element and the plurality of transverse grate elements having an interior working surface defining a wear surface across which material to be reduced traverses, and at least one stop extending outward of the discharge openings and having an upstream surface that is arcuate as the upstream surface extends away from the discharge openings such that the upstream surface curves in a direction opposite a direction of material flow over the interior working surface

wherein the plurality of discharge grate components are installed in the grate structure in a position between approximately 30 degrees and 180 degrees relative to the rotational axis of the rotary head.