EL type pulverizers
View Patent ↗Improvements in EL type pulverizers provide for longer wear life and reduced incidences of parts failures include: deep-dish contour grinding rings, tight tolerance ball tracks, heavy-duty top grinding ring flukes, larger diameter grinding balls, and an improved all-metal, integral snubber design for limiting the horizontal movement of the top grinding ring in order to increase the useful life of the pulverizer elements.
1. A top grinding ring for an EL type pulverizer comprising at least one integral snubber casted as part of the parent material of the top grinding ring and formed as a contour change on an outer edge of the top grinding ring, and a plurality of equally spaced apart flutes extending downwardly from the outer edge of the top grinding ring.
2. The top grinding ring according to claim 1 , wherein a integral snubber is oriented at an angle ∝ with respect to a radial line originating at a center of the grinding ring, angle ∝ having a value within a range of approximately 15 degrees to approximately 65 degrees.
3. The top grinding ring according to claim 2 , wherein angle ∝ has a value of approximately 28 degrees.
4. The top grinding ring according to claim 1 , further comprising a continuous arcuate grinding track formed on a bottom surface of the top grinding ring and adapted to receive a plurality of pulverizer balls each having an OD and circumference which roll against the arcuate grinding track.
5. The top grinding ring according to claim 4 , wherein the continuous arcuate grinding track has a diameter which is held to a circular tolerance within ±{fraction (1/16)} inches of its ultimate concentricity.
6. The top grinding ring according to claim 4 , wherein the continuous arcuate grinding track has an arcuate length that is at least 29% of the circumference of one of the plurality of pulverizer balls.
7. The top grinding ring according to claim 6 , wherein the continuous arcuate grinding track has an arcuate length which is held to a circular tolerance within ±{fraction (1/16)} inches of its ultimate curvature.
8. The top grinding ring according to claim 1 wherein the total circumferential length of all the equally spaced apart flutes exhibits an arcuate length of at least 50% of the total available circumference at the outer edge of the top grinding ring.
9. The top grinding ring according to claim 1 , comprising a plurality of integral snubbers, each of the integral snubbers being equally spaced around a circumference of the top grinding ring.
10. An EL type pulverizer, comprising: a housing, a top grinding ring having a continuous arcuate grinding track formed on a bottom surface of the top grinding ring and adapted to receive a plurality of pulverizer balls each having an OD and circumference, and at least one integral snubber casted as part of the parent material of the top grinding ring and formed on an outer edge of the top grinding ring, snubber attachment means attached to the housing for securing the integral snubber to the housing, and a plurality of equally spaced apart flutes extending downwardly from the outer edge of the top grinding ring.
11. The pulverizer according to claim 10 , wherein the snubber attachment means comprises a snubber bracket assembly including a snubber bracket secured to the pulverizer housing, a wear plate secured to the integral snubber, and a shim pack therebetween for adjusting a clearance between the snubber wear plate and the snubber bracket.
12. The pulverizer according to claim 11 , wherein the snubber attachment means is removably secured to the pulverizer housing and to a integral snubber to permit the snubber attachment means to be installed and dismantled from the pulverizer housing subsequent to top grinding ring installation and removal, the shim pack providing means to adjust or eliminate the clearance between the snubber wear plate and the snubber bracket.
13. The pulverizer according to claim 10 , comprising a bottom grinding ring having a continuous arcuate grinding track formed on a top surface of the bottom grinding ring and adapted to receive a plurality of pulverizer balls each having an OD and circumference which roll against the continuous arcuate grinding track, the bottom grinding ring having an arcuate length that is at least 23% of the total circumference of one of the plurality of pulverizer balls.
14. The pulverizer according to claim 13 , wherein the continuous arcuate grinding track formed on the top surface of the bottom grinding ring has a diameter which is held to a circular tolerance within {fraction (1/16)} inches of its ultimate concentricity.
15. The pulverizer according to claim 13 , wherein the continuous arcuate grinding track formed on a top surface of the bottom grinding ring has an arcuate length which is held to a circular tolerance within ±{fraction (1/16)} inches of its ultimate curvature.
16. The pulverizer according to claim 10 , wherein each of the plurality of pulverizer balls has a nominal OD of one of 12{fraction (1/14)} inches and 13⅝ inches when in a new condition and first installed in the pulverizer.
17. A top grinding ring for an EL type pulverizer comprising a plurality of equally spaced apart flutes extending downwardly from an outer edge of the top grinding ring, a continuous arcuate grinding track formed on a bottom surface of the top grinding ring and adapted to receive a plurality of pulverizer balls each having an OD and circumference which roll against the arcuate track, wherein the continuous arcuate grinding track has an arcuate length that is at least 29% of the circumference of one of the plurality of pulverizer balls.
18. The top grinding ring according to claim 17 , wherein the continuous arcuate grinding track has a diameter which is held to a circular tolerance within ±{fraction (1/16)} inches of its ultimate concentricity.
19. The top grinding ring according to claim 17 , wherein the continuous arcuate grinding track has an arcuate length which is held to a circular tolerance within ±{fraction (1/16)} inches of its ultimate curvature.
20. An EL type pulverizer comprising a top and a bottom grinding ring, a continuous arcuate grinding track formed on a top surface of the bottom grinding ring and adapted to receive a plurality of pulverizer balls each having an OD and circumference which roll against the arcuate grinding track, wherein the grinding track has an arcuate length that is at least 23% of the circumference of one of the plurality of pulverizer balls, and a plurality of spaced apart flutes extending downwardly from an outer edge of the top grinding ring.
21. The pulverizer according to claim 20 , wherein the continuous arcuate grinding track has a diameter which is held to a circular tolerance within ±{fraction (1/16)} inches of its ultimate concentricity.
22. The pulverizer according to claim 20 , wherein the continuous arcuate grinding track has an arcuate length which is held to a circular tolerance within ±{fraction (1/16)} inches of its ultimate curvature.