Specifying and Ordering Belt Cleaners
Information Needed: Belt Width, Conveyor Frame (structure) Width, Head Pulley Diameter, For Precleaners -What is the Belt’s Material Path, Material Conveyed (dry,wet,sticky,etc), Type of Belt Splice: Mechanical – Skived or Unskived, Vulcanized, Temperature or Other Extreme Environmental Factors, Does the Belt Reverse
Why are belt cleaners needed?
Saves Money / Increases belt wear life. / Extends life of rollers, pulleys, and splices. / High cost of accidents. / Reduces Maintenance Costs / Minimizes manual cleanup. / Protects against belt miss-tracking. / Reduces conveyor component replacement costs. / Reducing carry-back from 3% to 1% means a 67% reduction in maintenance costs. / Keeps Conveyors Running Efficiently and Consistently / Reduces unscheduled downtime. / Increases production up-time. / Improves Safety / Reduces housekeeping problems. / 42% of conveyor-related accidents happen while maintenance tasks are being done.
Types of belt cleaners
Pre-cleaners: Mounted on the head pulley. / Mounted below the material flow. / Blade is always narrower than the belt width. / Ideally, the blade covers just the belt’s material path. / Removes the big stuff. Typically cleans off up to 80% of the initial carry-back.
Secondary Cleaners: Located just past where the belt leaves the head pulley and anywhere down the belt-line. / Special secondaries may allow for mounting under the head pulley. / Blade width is always the belt width or wider. / Removes sticky fines – the final cleaning job. / Cleaning efficiency can be 90% +. / May require a hold-down roller for maximum performance.
Specialty Cleaners: Pre-cleaners or Secondaries designed especially for specific or extreme applications.
Definition of Terms
Carry-back-Material that sticks to the belt after it leaves the transfer point and continues falling off along the conveyor’s return side. / Material Path – The section of the belt where most of the material is conveyed. / Typically the center 2/3 of the belt. / Hold-Down Roller – A stabilizing roller located on top of the return side of the belt to prevent belt flap or to provide a consistent flat surface for the blades on lighter-tensioned belt.
Types of cleaner blades
Urethane Blades: Not all urethane’s are the same. Urethane blades are specially formulated for abrasion resistance and long wear. / Easy on the belt. / Work well with mechanical splices. / Economical. / Specialty formulations for high heat or water removal. / Less advanced urethane formulations result in blades that experience quicker wear and provide less efficient cleaning.
Tungsten Carbide: Excellent for superior cleaning efficiency and long wear. The quality and application of carbides can vary. / Superior cleaning. / Long Wear. / C-Tips/blades for mechanical splices and V-Tips/blades for vulcanized belts.
The “Material Path” Option (for Pre-cleaners): For optimal cleaning and reduced blade re-tension, the cleaner blade width should be sized to fit the material path of the belt. The material path is typically the center 2/3 of the belt width. Choosing a blade only slightly wider than the material path can decrease differential blade wear which reduces blade re-tension maintenance, as well as reducing the frequency of blade replacement.
Blade Angle (Secondary cleaners)
1. Aggressive – excellent clean-ability, high risk for belt damage.
2. 90° to belt – good cleaning efficiency; must have good blade relief for splices.
3. Wiping – a little less cleaning power; safer on belts in poor condition or with poor mechanical splices.
Belt cleaning systems
Many applications will require more than one belt cleaner to do a satisfactory cleaning job. A typical system includes a pre-cleaner (to knock off the initial flow of carry-back), one or more secondary cleaners (to take off the sticky fines) and many times, a final specialty cleaner (to remove the water).
Keys to Good Belt Cleaning
- Proper cleaner selection for the application.
- Correct installation.
- Regular service maintenance.