CONTACT US ABOUT US EMPLOYMENT

1.800.348.4RPM

RPM and Associates, Inc. Rapid City, SD

Products and Services -> Coal Pulverizers

Sub-links: Rolls | Journals | Tables | Wear Liners

Rolls

MPS 89 Coal Pulverizer Roll With Chrome Carbide OverlayRPM & Associates has 25+ years of experience rebuilding existing coal pulverizer rolls. We also manufacture new rolls from cast steel cores. All of our rolls are surfaced with a CP3 chrome carbide overlay to ensure the roll has a long production life and are machined to a unique profile that minimizes the possibility of spalling.

Click on one of the links below to proceed to your particular area of interest.

Rebuilt Rolls

(Return to top)

We rebuild existing coal pulverizer rolls at our facility in Rapid City, SD. Worn rolls are shipped to our shop, inspected, scanned with a CMM, preheated, and welded under strict parameters with our CP3 chrome carbide overlay. Roll bores are checked again following the overlay process, then, if necessary, finish-machined to provide a perfect fit. Each roll is assigned an RPM number with which wear and rebuild data is recorded for future reference.

Following is an overview of the process that we follow for a typical roll when it arrives and is rebuilt at our facility.

     
  • Inspections of Worn Pulverizer Rolls Received at RPM
    • Metal Template Fit To OD Profile
    • Visual Inspection of Wear Profile/Anomalies
    • CMM Inspection of ID Bore and OD Profile
    • Dye Penetrant Inspection of ID Bore
  • All Rolls Are Assigned an Identification Number
Typical Worn CE1043 Coal Pulverizer Roll
Typical Worn CE 1043 Roll
Template Inspection of CE1003 Coal Pulverizer Roll
Template Inspection of
CE1003 Roll
Template Inspection of CE1003 Coal Pulverizer Roll
Template Inspection of
CE1003 Roll
Template Inspection of CE1003 Coal Pulverizer Roll
Template Inspection of
CE1003 Roll
CMM Inspection of MPS89 Coal Pulverizer Roll
CMM Inspection of
MPS89 Roll
CMM and Die Penetrant Inspection of CE863 Coal Pulverizer Roll
CMM and Die Penetrant Inspection
of CE863 Roll
RPM Identification Number Placed On Each Rebuilt Coal Pulverizer Roll
RPM Identification Number
  • Pre-Repairs Performed Include Air Arcing of OD as Required
  • ID Bores Machined as Required
  • Rolls Are Preheated and Rebuilt Using Automatic Welding System
  • Rolls Are Allowed to Slow Cool
  • Metal Template, CMM and Die Penetrant Inspections Are Performed Again When Welding is Complete and Roll is Cool
  • All Data is Recorded on Job Sheets and May Be Used in RPM “Pulverizer Wear Parts Monitoring Program”
 Automatic Air Arcing Chrome Carbide Overlay on Coal Pulverizer Roll
Automatic Air Arcing
Machining ID Bore of a Coal Pulverizer Roll
Machining ID Bore
Pre-heating Coal Pulverizer Roll
 Pre-heating Roll
Rebuilt CE1003 Coal Pulverizer Roll With Hardfaced Heel
Rebuilt CE1003 Roll With Hardfaced Heel

Pulverizer Roll Profiles

(Return to top)

A number of different roll profiles are available. The table below describes the key features for each.

 
Original Style Coal Pulverizer Roll Profile One Piece Coal Pulverizer Roll Profile One Piece Reduced Weight Profile Coal Pulverizer Roll Cast Steel Core Profile

ORIGINAL STYLE

  • Very durable
  • Low wear resistance
  • Does not crack
  • NiHard sometimes spalls off cast iron
  • Cannot repair bore
  • OD is rebuild/welder friendly

ONE PIECE 

  • Typically a high chrome material
  • Sometimes cracks even when new
  • Wear is a little bit better than NiHard
  • Not very rebuild/welder friendly

ONE PIECE 
REDUCED WEIGHT

  • Same properties as One Piece
  • Higher chance for breakage
  • Not very rebuild/welder friendly at all

CAST STEEL CORE
HARDFACED OD

  • One-time forever purchase
  • Chromium Carbide hardface overlay has 2-3 times wear life over any other options
  • Will not break or crack
  • Bore can be repaired
  • Be careful to get enough overlay on new rolls

New RPM Cast Steel Core Rolls

(Return to top)

RPM & Associates manufactures new coal pulverizer rolls from cast steel cores. The cores are machined to fit the profile of the roll being replaced and a hardfaced surface is added to improve wear-life.

Cast steel cores have many advantages.

  • Cast Steel Parts Will Not Crack or Break
  • Cast Steel Alloys Resist Heat Better Than Cast Iron Parts
  • Cast Steel is Weldable – ID, OD, Anywhere!
  • Cast Steel Cores are “Forever Purchases” as They are Always Repairable

Typical cast steel cores are shown below along with photos showing transformations of a cast steel core into a CE1043 and Foster Wheeler MB 23.5 rolls.

OEM Core vs. RPM Coal Pulverizer Roll Core MPS89 with Steel Core
MPS89 with Steel Core
New CE1043 Cast Steel Coal Pulverizer Roll Core
New CE1103 Cast Steel Rolls
Hub Rebuild
Hub Rebuild

Cast Steel Profiles

Cast steel core rolls have a standard profile and an optional profile.

Place your mouse over the profile to see an expanded view.

Cast Steel Core Profile
Optional Steel Core Profile
Cast Steel Core Profile
Standard Steel Core Profile
RPM Services
 

Available Alloy Options

The following alloys are available for hardfacing rolls.

  • Standard High Chrome Carbide with Molybdenum Such as Stoody 100HC
  • Micro-Alloyed High Chrome Carbides Such as RPM-CP3 Which has ~30% Increased Wear Life Over Standard High Chrome Carbide Alloys
  • Continuous Wear Band of Tungsten Carbide Chips Embedded in High Chrome Carbide

Continuous Tungsten Carbide Chip Wear Band

RPM & Associates can apply a tungsten carbide chip wear band over the high-wear areas of rolls to extend the performance life. Place your mouse over the smaller image on the left to show the larger image on the right.

Place your mouse over the smaller image on the left to show the larger image on the right.

Continuous Tungsten Carbide Chip Wear Band
  Continuous Tungsten Carbide Chip Wear Band  

   

   
RPM & Associates can apply a tungsten carbide chip wear band over the high-wear areas of rolls to extend the performance life.

Place your mouse over the smaller image on the left to show the larger image on the right.

Roll Photo Gallery

A gallery of miscellaneous photos relating to rolls is shown below. Place your mouse over the smaller image on the left to show the larger image on the right.

Place your mouse over the smaller image on the left to show the larger image on the right.

Cast Steel with Tungsten Carbide Wear Band
  Cast Steel with Tungsten Carbide Wear Band  
HP863
  HP863  
MPS 89
  MPS 89  
Spalling Example
  Spalling Example  
Badly Worn CE1003
  Badly Worn CE1003  
Modified Profile Reduces Spalling Potentia
  Modified Profile Reduces Spalling Potentia  

  "Ribs" added to standard profile  
A gallery of miscellaneous photos relating to rolls is shown below.

Place your mouse over the smaller image on the left to show the larger image on the right.

About RPM & Associates

About RPM and Associates

RPM laser cladding can make your worn shaft better-than-new with a variety of laser-deposited alloys that eliminate spalling.

Rapid City, the Black Hills, and South Dakota ... Our Home

About Rapid City and the Black Hills

Many bald eagles live in the Black Hills region, but are rarely seen. The female Eagle is 25% larger than the male, and can weigh over 17lbs with an 8-foot wingspan.