An Accuweigh Conveyor Scale is a conveyor belt weighing system manufactured under the Accuweigh® brand. It is installed on a conveyor belt to continuously measure the weight and flow rate of bulk material like coal, limestone, clinker, ash, or ore while the conveyor is running. It is widely used in coal handling plants (CHP), thermal power plants, mines, and cement plants.
The scale works by measuring:
- Material load on the belt
- Conveyor belt speed
Then the controller calculates:
- Tons per hour (TPH)
- Total material conveyed
Basic working formula:
Where:
- = Flow rate
- = Belt load
- = Belt speed
Accuweigh Conveyor Scale Installation Guide
1. Select Proper Conveyor Location
Choose a straight and stable conveyor section.
Avoid installation near:
- Loading point
- Head pulley
- Tail pulley
- Belt tripper
- Conveyor take-up
- Vibrating equipment
Recommended:
- At least 5 idler spacing away from loading zone
- Conveyor structure should be rigid and vibration-free
2. Check Conveyor Condition
Before installation:
- Belt should run centrally
- Idlers must rotate freely
- No belt sway or mistracking
- No material buildup
- Equal idler spacing required
Poor conveyor condition causes weighing error.
3. Install Weigh Frame
Remove existing idler and fit the Accuweigh weigh frame.
Available types:
- Single idler
- Dual idler
- 3 idler
- 4 idler
- 6 idler weigh frame
Steps:
- Isolate conveyor power
- Remove conveyor idler
- Mount weigh frame on stringer
- Center and level properly
- Tighten all bolts
4. Align the Idlers
This is one of the most important steps.
Use string line method:
- Align 2–3 idlers before scale
- Align 2–3 idlers after scale
- All idlers should touch string equally
Improper alignment causes:
- Zero fluctuation
- Incorrect TPH reading
- Belt wandering
5. Install Load Cells
Load cells are mounted in the weigh frame.
Important points:
- Load cells must move freely vertically
- Avoid side pressure
- Do not overtighten bolts
- Protect cable from damage
Accuweigh uses counter-balanced design to measure only material load and reduce dead load effect.
6. Install Speed Sensor
The speed sensor measures belt speed.
Usually installed on:
- Tail pulley
- Return belt
- Speed wheel assembly
Guidelines:
- No slipping allowed
- Proper wheel contact required
- Install close to scale location if possible
7. Electrical Wiring
Connect:
- Load cells
- Speed sensor
- Junction box
- Integrator/controller
Precautions:
- Use shielded cable
- Proper grounding required
- Avoid routing near power cables
8. Calibration
After installation perform:
Zero Calibration
Done with empty running belt.
Span Calibration
Using:
- Test weights
- Calibration chain
- Material test
Material test gives best accuracy.
9. Final Checks
Verify:
- Stable zero reading
- Correct TPH display
- Smooth belt movement
- No rubbing or vibration
Totalizer working properly
Important Practical Tips for CHP
- Install in low vibration zone
- Keep conveyor idlers clean
- Avoid welding on scale frame
- Regularly check calibration
- Maintain proper belt tracking
- Use weigh quality idlers near scale
