Conveying & Transfer

Choose a conveying system around the required throughput, physical route, powder behavior, and acceptable product change. Pneumatic regime, mechanical loading, pickup, and receiving equipment must work together across the complete cycle. Verify particle integrity, composition, residual material, and containment as well as transfer rate. Neither a successful delivery nor a dense-phase label establishes that the system meets the product requirement.

Specify performance at the destination and include the operating time available to achieve it.

Use material measurements to define trial conditions and exclude unsuitable options.

Select the unresolved requirement before comparing equipment proposals.

Pneumatic transport uses a gas stream and requires material entry, a conveying line, gas-solid separation, and a gas mover. Mechanical conveyors move material using a screw, belt, chain, cable, buckets, or vibratory motion. Gravity transfer uses available elevation but still needs controlled entry and discharge.

Compare routing, energy, wear, access, and cleaning alongside capital cost. A short direct mechanical route may be attractive where a pneumatic circuit would require substantial ancillary equipment. Conversely, a pipe route may fit a constrained installation better than a conveyor structure. Assess the actual layout rather than treating either family as universally superior.

Decision output: Define the candidate principle and its system boundary, including all drives, gas handling, supports, controls, and receiving equipment.

Pressure and vacuum describe the driving pressure arrangement. Dilute and dense phase describe the gas-solid transport regime. Pressure is not synonymous with dense phase, and vacuum is not synonymous with dilute phase.

Dilute-phase systems normally rely on particles being transported in suspension. Dense-phase systems use more concentrated structures that depend on the material and equipment. Lower gas velocity can reduce some impact damage, but friction, compression, unstable plugs, or inlet hardware can still damage the product. Do not convert a dilute-phase line to dense phase merely by reducing air.

Decision output: Confirm the available stable operating region through relevant material evidence, conveying trials, and design calculations; avoid a universal velocity or solids-loading cutoff.

For pneumatic transfer, calculate pressure losses and local gas conditions along horizontal and vertical sections, bends, valves, and the receiver. Superficial gas velocity is actual volumetric gas flow divided by pipe area; it is not particle velocity. State pressure and temperature when reporting flow.

For fixed gas mass flow, changes in gas density and pipe area change velocity along the line. Check both pickup and downstream sections rather than relying on inlet velocity alone. For mechanical transport, assess loading, inclination, drive duty, transfer points, and loaded starting conditions. Changes in route require reassessment of capacity and product exposure.

Decision output: A route-specific design with operating margins, access for maintenance, and a documented basis for extrapolating trial results.

Set acceptable changes in PSD, fines, shape, coating integrity, and composition before testing. Damage can occur at entry, bends, mechanical clearances, discharge, and separation, not just in the main conveying length.

Compare representative inlet and outlet samples. Where segregation matters, sample across receiver filling and drawdown instead of relying only on a combined batch. Distinguish single-pass effects from cumulative changes in recirculating test loops. A lower measured fines fraction may reflect fines captured elsewhere rather than reduced attrition.

Decision output: A qualified operating range supported by product-quality measurements and a mass balance that accounts for receiver product, collected fines, and residual material.

Define how material enters the conveyor and whether supply is controlled or flood-fed. An inlet device must provide the required feed without unacceptable gas leakage, surging, or damage. Coordinate metering requirements with Feeding & Dosing.

Size receiver working capacity, separation, filter duty, venting, and discharge around the incoming gas and solids load. Check whether discharge interrupts collection and whether the next process needs deaerated powder or a buffer. An intermittent receiver can limit system throughput even when the line has sufficient instantaneous capacity.

Decision output: A complete cycle and interface specification, including destination availability, filter condition, residual inventory, and downstream material state.

Specify the required enclosure, leakage performance, gas quality, product-contact materials, and residue limits. Vacuum can favor inward leakage in negative-pressure sections, but it does not demonstrate containment during discharge, filter handling, or maintenance.

Provide access to retained-product locations and define cleaning verification. Assess conveying-gas moisture and temperature where they can change the powder. Address combustible dust, ignition sources, static electricity, pressure, and isolation through the applicable specialist hazard assessment. A sealed conveyor is not automatically an explosion-protected system.

Decision output: A verifiable containment and cleaning specification with clear responsibility for hazard controls and maintenance access.

Compare alternatives using the complete duty, including pickup and receiving equipment.

Qualify settings against both delivery and material quality.

Characterization narrows options; representative equipment trials and calculations establish design performance.

Record material, route, settings, measurement uncertainty, duration, and deviations. Assess the whole cycle rather than selecting only a stable interval.

The transport system begins at material pickup and ends when the receiving process can use the product.

For an installed system, use Attrition, Breakage and Wear, Segregation and Blend Inconsistency, or Poor Flow and Discharge. Use the findings to define the equipment or operating change that needs verification.

<p>Explore conveying mode, particle damage, and system design.</p>

Use these boundaries when reviewing an equipment proposal.