AU2011100764A4 - System and method for conversion of ball and race coal pulverizers to roll and race coal pulverizers - Google Patents

Abstract

The present invention relates generally to the field of coal pulverizers and, in particular, to a new and useful system and method for the conversion of ball and race coal pulverizers to roll and race coal pulverizers. In another embodiment, the system and method of the present invention permits the conversion of one type of coal pulverizer to another type of coal pulverizer through the conversion of only a portion of the old pulverizer and eliminates the need to replace the total unit, thereby permitting a substantial cost and time savings. -50 il2-130

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Innovation Patent Applicant(s): Babcock & Wilcox Power Generation Group, Inc. Invention Title: SYSTEM AND METHOD FOR CONVERSION OF BALL AND RACE COAL PULVERIZERS TO ROLL AND RACE COAL PULVERIZERS The following statement is a full description of this invention, including the best method for performing it known to me/us: /1 P87465.AU -2 SYSTEM AND METHOD FOR CONVERSION OF BALL AND RACE COAL PULVERIZERS TO ROLL AND RACE COAL PULVERIZERS FIELD AND BACKGROUND OF THE INVENTION 1. Field of the Invention (0001] The present invention relates generally to the field of coal pulverizers. 2. Description of the Related Art [0002] Coal pulverizers of various types are known in the art. To date, when a operator desires to change the type of coal pulverizer that is being utilized in, for example, a power generating plant, such operators have to "shut down" at least one coal pulverizer at a time, and maybe all the coal pulverizers, thus curtailing or idling the coal-fired steam producing device in question, and undertake an expensive and time consuming replacement operation. Such replacement operations generally require the complete pulverizer replacement including new foundation modifications, a new motor, a new gear box, a new yoke, various duct modifications, and a new pulverizer bottom housing, including primary air chamber and yoke air seal assembly. Given the costs and "down time" associated with such a replacement operation such replacement operations are hardly ever undertaken unless absolutely necessary. [0003] However, various types of older coal pulverizers are inefficient to operate and/or maintain. Thus, there is a need in the art for a system and method that would permit the conversion of one type of coal pulverizer to another type of coal pulverizer that is more efficient and/or maintenance-friendly. SUMMARY OF THE INVENTION [0004] Accordingly, one aspect of the present invention is drawn to a method for conversion of a ball and race coal pulverizer to a roll and race coal pulverizer, the method comprising the steps of: (i) removing the ball and race coal pulverizer components, while retaining at least the foundation of the ball and race coal pulverizer; (ii) placing the operating portion of a roll and race coal pulverizer on at least the foundation of the ball and race coal pulverizer; and (iii) mating the operating portion of a -3 roll and race coal pulverizer to at least the foundation of the ball and race coal pulverizer. [0005] This provides a new and useful system and method for the conversion of ball and race coal pulverizers to roll and race coal pulverizers. In another embodiment, the system and method of the present invention permits the conversion of one type of coal pulverizer to another type of coal pulverizer through the conversion of only a portion of the old pulverizer and eliminates the need to replace the total unit, thereby permitting a substantial cost and time savings [0005a] In one form, a lOE10 Coal Pulverizer is converted to a B&W Roll Wheel size 75 Coal Pulverizer. [0005b] In one form, the following portions of the ball and race coal pulverizer are retained in addition to the bottom housing of the ball and race coal pulverizer: (a) at least one reduction gear box; (b) at least one yoke; (c) at least one hot air duct (d) at least one support cone; (e) at least a portion of the PF mill housing;, and (d) at least one outlet turret. [0005c] In one form, the following portions of a roll and race coal pulverizer are mated to the retained portions of the ball and race coal pulverizer: (a) at least one grinding ring assembly, including at least one ring seat cover 20 and twelve rotating throat segments; (b) at least three roll wheel assemblies, at least six pivot pins, at least one pressure frame, at least fifteen springs and at least one spring frame; (c) at least one intermediate housing, including at least twelve outer wall segments, at least twelve ledge covers, at least one new adaptor flange and gussets; and (d) at least one top housing, including at least one classifier discharge assembly, at least one classifier cone assembly, and at least three roll wheel seal air assemblies. [0006] In yet another aspect of the present invention, there is provided a system and method for the conversion of a ball and race coal pulverizer to a roll and race coal pulverizer, the method comprising one or more steps as shown and described herein. [0007] The various features of novelty are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific benefits attained by its uses, -4 reference is made to the accompanying drawings and descriptive matter in which exemplary embodiments of the invention are illustrated. BRIEF DESCRIPTION OF THE DRAWINGS [0008] FIGURE 1 is a schematic representation of a Prior Art ball and race coal pulverizer (e.g., British 1 OE10); [0009] FIGURE 2 is a schematic representation of a Prior Art roll and race coal pulverizer (e.g., Babcock & Wilcox B&W Roll Wheel size 75); [0010] FIGURE 3 is a schematic representation of a converted coal pulverizer formed in accordance with the system and method, where the coal pulverizer of FIGURE 3 has a ball and race foundation mated to a roll and race operating portion; and [0011] FIGURE 4 is an exploded schematic view of the components that are utilized in conjunction with the system and method to convert a ball and race coal pulverizer to a roll and race coal pulverizer. DESCRIPTION OF THE INVENTION [0012] While the present disclosure will be described in terms of the conversion of a one specific model of ball and race coal pulverizer to one specific model of roll and race coal pulverizer, it is not limited to just this type of conversion. Rather, the system and method can be applied equally to the conversion of various models of ball and race coal pulverizer to various models of roll and race coal pulverizer. [0013] As illustrated in FIGURE 1, there is shown a schematic representation of a Prior Art British lOE10 pulverizer is shown. Such coal pulverizers are known in the art and thus a detailed description of the components and working thereof is omitted herein for the sake of brevity. Regarding FIGURE 1, reduction gear box 170, the yoke (not pictured), hot air duct 190, bottom housing 180, a portion of the PF mill housing 200, and outlet turret 210 of a 10E10 Coal Pulverizer are retained for the conversion system and method that is described herein. The remainder of the mill is then removed and/or disassembled and the above-mentioned components of the ball and race pulverizer are retained.

-5 [0014] As discussed above, FIGURE 2 is a schematic representation of a roll and race B&W Roll Wheel size 75 coal pulverizer. FIGURE 3 is a schematic representation of a converted coal pulverizer formed in accordance with the system and method of the present invention, where the coal pulverizer of FIGURE 3 has a ball and race bottom housing 180 mated to a roll and race operating portion. [0015] As can be seen from FIGURE 4, FIGURE 4 is an exploded schematic view of the components that are utilized in conjunction with the system and method to convert a ball and race coal pulverizer to a roll and race coal pulverizer. As illustrated in FIGURE 4, the system and method of the present disclosure entail removal of various components of a ball and race coal pulverizer with the retention of reduction gear box 170, the yoke (not pictured), hot air duct 190, support cone 180, a portion of the PF mill housing 200, and outlet turret 210 of a 1OE10 Coal Pulverizer. Next, the remainder of the ball and race coal pulverizer is converted to a roll and race coal pulverizer in accordance with the exemplary method described below. [0016] The removed components of the 10E10 ball and race pulverizer are replaced with components of a B&W Roll Wheel size 75 roll and race pulverizer. Grinding ring assembly 10, including ring seat cover 20 and twelve rotating throat segments 30 are attached to the yoke (not pictured). Three roll wheel assemblies 70, six pivot pins 80, pressure frame 90, fifteen springs 100 and spring frame 120 are stacked on grinding ring seat assembly 10. Intermediate housing 60, including twelve outer wall segments 40, twelve ledge covers 50, new adaptor flange 250 and gussets 260 is attached to the existing PF mill housing 200. Top housing 160, including classifier discharge assembly 150, classifier cone assembly 150, and three roll wheel seal air assemblies 140 are attached to intermediate housing 60. The existing outlet turret 210 is attached to top housing 160. Three loading rod and seal assemblies 110 are attached to intermediate housing 60 and spring frame 120. Three new loading rod tensioning assemblies 270 are attached to the loading rods 110 and the adaptor flange 250. [0017] Given the above, in one embodiment, the present disclosure provides a system and method for the conversion of a ball and race coal pulverizer to a roll and race coal pulverizer thereby providing the high capacity, smooth operation, long life, and -6 lower maintenance of a roll and race coal pulverizer while realizing the cost savings associated with the use of the existing bottom housing, primary air chamber, primary air duct, and drive system of the ball and race pulverizer. [0018] While specific embodiments of the present disclosure have been shown and described in detail to illustrate the application and principles of the invention, it will be understood that it is not intended that the present invention be limited thereto and that the invention may be embodied otherwise without departing from such principles. In some embodiments of the invention, certain features of the invention may sometimes be used to advantage without a corresponding use of the other features. Accordingly, all such changes and embodiments properly fall within the scope of the following claims. [0019] It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country. (0020] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Claims (5)

1. A method for conversion of a ball and race coal pulverizer to a roll and race coal pulverizer, the method comprising the steps of: (i) removing the ball and race coal pulverizer components, while retaining at least the bottom housing of the ball and race coal pulverizer; (ii) placing the operating portion of a roll and race coal pulverizer on at least the bottom housing of the ball and race coal pulverizer; and (iii) mating the operating portion of a roll and race coal pulverizer to at least the bottom housing of the ball and race coal pulverizer.

2. The method of claim 1, wherein a 10E10 Coal Pulverizer is converted to a B&W Roll Wheel size 75 Coal Pulverizer.

3. The method of claim 1, wherein the following portions of the ball and race coal pulverizer are retained in addition to the bottom housing of the ball and race coal pulverizer: (a) at least one reduction gear box; (b) at least one yoke; (c) at least one hot air duct (d) at least one support cone; (e) at least a portion of the PF mill housing;, and (d) at least one outlet turret.

4. The method of claim 3, wherein the following portions of a roll and race coal pulverizer are mated to the retained portions of the ball and race coal pulverizer: (a) at least one grinding ring assembly, including at least one ring seat cover 20 and twelve rotating throat segments; -8 (b) at least three roll wheel assemblies, at least six pivot pins, at least one pressure frame, at least fifteen springs and at least one spring frame; (c) at least one intermediate housing, including at least twelve outer wall segments, at least twelve ledge covers, at least one new adaptor flange and gussets; and (d) at least one top housing, including at least one classifier discharge assembly, at least one classifier cone assembly, and at least three roll wheel seal air assemblies.

5. A system and method for the conversion of a ball and race coal pulverizer to a roll and race coal pulverizer, the method comprising one or more steps as shown and described herein.