Getting barite from a silo to a mix tank in an exact amount is a two-part problem: conveying the powder reliably, and weighing it accurately. Pneumatic conveying moves it through pipework on air; load cells measure it by mass. Getting both right is what makes a weight-up repeatable. This page covers the dry-bulk delivery chain.
Dense-phase versus dilute-phase
Pneumatic conveying uses air to move powder through a pipeline, and the regime matters. Dense-phase conveying uses high pressure and low velocity to move material as slugs or plugs, which is gentle on the line and the product and well suited to abrasive barite; dilute-phase conveying suspends material in a high-velocity air stream, which is simpler but far more abrasive at the bends. Mud plants generally favour dense-phase for barite to limit wear and degradation.
Airlocks and blowers
A rotary airlock (rotary valve) meters material into the conveying line while holding back system pressure, and a blower or compressor supplies the conveying air. The airlock's condition sets how well the line conveys: as its rotor vanes wear in the abrasive stream they leak air back up into the silo, conveying pressure and rate fall, and the whole chain slows even though the blower is working as hard as ever — a classic, gradual, easily-missed loss of performance.
Velocity, bends and wear
Conveying velocity has to sit in a window: too low and material drops out and blocks the line, especially at bends; too high and the abrasive stream blasts and erodes the pipe and long-radius bends. Line routing, bend radius and velocity control are tuned to stay in that window, and wear at bends is monitored because a worn elbow is a failure waiting to happen.
Weighing by load cell
Material is delivered to a weigh hopper mounted on calibrated load cells, so the plant adds an exact mass by gain-in-weight (weighing material in) or loss-in-weight (weighing it out of a feeder). Mass, not volume, is what makes a weight-up accurate and repeatable — bulk density varies with aeration and packing, so a volumetric measure would drift, while a weighed mass does not.
Interlocked, recorded control
The conveying and weighing run as an interlocked control sequence — airlock, blower, diverter valves and weigh hopper operating in the correct order so steps cannot fight each other — with each addition logged against the batch. That sequencing prevents over-pressure and mis-routing, and the record turns a weight-up into a traceable, repeatable operation.
Convey then weigh, reliably
The dry-bulk chain succeeds when conveying is reliable and weighing is accurate: dense-phase conveying moves barite gently, a sound airlock meters it, velocity control keeps the line clear and intact, and calibrated load cells turn it into an exact, recorded mass. Those are the foundations of every accurate barite addition.
Key takeaways
A mud plant conveys dry bulk by pneumatic conveying — favouring dense-phase, high-pressure, low-velocity flow for abrasive barite — metered by a rotary airlock and driven by a blower, within a velocity window that avoids both blockage and erosion. It is weighed on calibrated load cells by gain- or loss-in-weight, because mass is repeatable where volume drifts, all under interlocked, recorded control. Reliable conveying plus accurate weighing is what makes barite addition exact.