0.5
Accuracy Class
0 – 2,000 t/h
Capacity
500 – 1,400 mm
Belt Width
0.3 – 2 m/s
Belt Speed
DEFINITION & OVERVIEW
What is a Belt Weigher & Weigh Feeder?
A belt weigher measures the mass flow rate of material on a moving conveyor continuously, in real time, rather than relying on periodic manual sampling or downstream tonnage reconciliation. A weigh feeder goes a step further: it doesn't just measure flow; it controls it, trimming belt speed against a set flow rate so that instantaneous throughput actually tracks the target.
John Finlay's belt weigher uses a dual load cell symmetric frame design, where horizontal belt force self-cancels across the two cells, a mechanical detail that matters because horizontal force is a common source of weighing error on asymmetric single-cell designs, particularly as belts age and tension varies.
A self-tensioning and anti-drift device holds belt tension constant through the weighing zone, which is what lets the system hold accuracy class 0.5 over time rather than only when freshly calibrated.
How It Works
Dual load cells read belt force continuously; weigh electronics combine that with belt speed to compute mass flow, trimming speed to hold a set point where feeder control is used.
Self-Tensioning Design
An anti-drift device holds belt tension constant through the weigh zone, protecting accuracy as the belt ages.
Role in Plant Reporting
Totalized, shift, and production data are available directly at the indicator and via 4–20 mA / RS485 output to SCADA.
Parameter | Value |
|---|---|
Accuracy Class | 0.5 |
Capacity | 0 – 2,000 t/h |
Belt Width | 500 – 1,400 mm (non-standard widths available) |
Belt Speed | 0.3 – 2 m/s |
Incline Range | 0 – 20° |
Load Cell Configuration | Dual load cell, symmetric frame |
Drive | Shaft-mounted VFD (no low-speed motor heating) |
Weigh Electronics | 85–265 V AC, RS485, 4–20 mA, large LCD |
KEY FEATURES
Key Features & Performance Highlights
The mechanical design choices behind this belt weigher specifically hold accuracy over years of continuous duty, not just at commissioning.
Dual Load Cell Symmetric Frame
Horizontal belt force self-cancels across the two symmetrically placed load cells, a design that resists the horizontal-force error common on single-cell or asymmetric weighing frames.
Self-Tensioning and Anti-Drift Device
Holds belt tension constant through the weigh zone, automatically protecting accuracy class 0.5 performance as the belt stretches and ages in service.
Shaft-Mounted VFD Drive
Where used in weigh feeder mode, the shaft-mounted VFD drive avoids the low-speed motor heating that affects some alternative drive arrangements running continuously at reduced speed.
WORKING PRINCIPLE
How the Belt Weigher & Weigh Feeder Works
The control sequence for weigh feeder mode shows how weighing and speed control combine into flow control.
Belt Weigher Starts
The belt weigher starts as part of the plant start sequence, with dual load cells and speed sensing active immediately.
Weight and Speed Reading
Weigh electronics continuously read instantaneous belt load and belt speed.
Flow Calculation
Mass flow rate is calculated from load and speed together, not load alone; this is what makes it a flow measurement rather than a simple weight reading.
Speed Trim Against Set Point
In weigh feeder mode, belt speed is trimmed against the set flow rate so instantaneous flow tracks the target continuously.
Data Output
Totalized output, shift output, and production data are available at the indicator, with 4–20 mA and RS485 signals feeding plant SCADA.
TECHNICAL SPECIFICATIONS
Belt Weigher & Weigh Feeder | Full Specification
Specifications sourced directly from John Finlay’s instrumentation documentation.
Parameter | Value |
|---|---|
Accuracy Class | 0.5 |
Capacity | 0 – 2,000 t/h |
Belt Width | 500 – 1,400 mm (non-standard widths available) |
Belt Speed | 0.3 – 2 m/s |
Incline Range | 0 – 20° |
Load Cell Configuration | Dual load cell, symmetric frame (horizontal force self-cancelling) |
Tensioning | Self-tensioning and anti-drift device |
Drive | Shaft-mounted VFD (no low-speed motor heating) |
Weigh Electronics | 85–265 V AC, RS485, 4–20 mA, large LCD display |
COMPARISON
Continuous Belt Weighing vs. Periodic Estimation
With Belt Weigher & Weigh Feeder
Periodic / Estimated Tonnage Tracking
Applications of the Belt Weigher & Weigh Feeder
Continuous belt weighing is used anywhere a coal washery needs real-time throughput data or flow control on a conveyed stream.
Plant Production Reporting
Continuous, totalized tonnage data replaces manual or downstream-reconciled estimates for shift and production reporting.
Feed Rate Control
In weigh feeder mode, the belt speed is automatically trimmed to maintain a set flow rate into downstream processing.
Blending and Proportioning
Accurate, continuous flow measurement supports blending applications where multiple streams need to be proportioned by mass.
SCADA-Integrated Throughput Monitoring
4–20 mA and RS485 outputs feed plant automation directly, without a separate manual data entry step.
Custody Transfer and Dispatch Verification
Continuous, accurate weighing supports verifying dispatch tonnage independently of downstream weighbridge figures.
Retrofitting Existing Conveyors
Available across a 500–1,400 mm belt width range, with non-standard widths available for existing conveyor retrofits.
About John Finlay
Belt Weighing Instrumentation Supplier in India
Why John Finlay?
0.5
Accuracy Class
This is held in place by the self-tensioning, anti-drift frame design.
130+
Coal Washery Projects
Completed EPC projects worldwide, including Asia’s largest coking coal washery at 30 MTPA.
EPC
Full Circuit Supply
Supplied as part of a complete instrumentation and automation offering, integrated with plant SCADA and process control.
IN
India-Based Support
Manufactured at Hefei John Finlay Mining Equipment Co., Ltd. and supported locally in India for installation, commissioning, spares and service.
Belt Weigher & Weigh Feeder | Frequently Asked Questions
Common questions from engineers in coal washery processes evaluating continuous belt weighing.
A belt weigher continuously measures mass flow rate on a moving conveyor. A weigh feeder does the same measurement but also controls it, trimming belt speed against a set flow rate so instantaneous throughput tracks a target measurement versus measurement plus control.
It holds accuracy class 0.5, supported by a dual load cell symmetric frame that self-cancels horizontal belt force and a self-tensioning device that holds belt tension constant over time.
The range covers 0–2,000 t/h capacity, 500–1,400 mm belt width (non-standard widths available), 0.3–2 m/s belt speed, and 0–20° incline.
Yes. The weigh electronics output both 4–20 mA and RS485 signals, and totalized shift and production data are available directly at the indicator.
Yes, the belt width range and non-standard width availability support retrofitting onto most existing conveyor structures without a full redesign.
Still estimating tonnage instead of measuring it?
Our engineers can help you specify a belt weigher or weigh feeder for your existing conveyor.
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