Pneumatic Conveying System Requirements

Pneumatic Conveying System Requirements

Primary intent: Specify material properties, throughput, route and supplier-design boundaries before selecting the air mover.

Required asset: Pneumatic Conveying System Enquiry Specification

1 — Engineering Answer

Pneumatic conveying is a bulk-solids transport problem, not a compressor-sizing problem disguised as a tonnes-per-hour request. Material behaviour, solids rate, conveying regime, pipeline geometry, feeder, receiver, gas condition, filtration and operating sequence jointly determine the pressure-flow duty.

2 — Start With the Material

Record product or grade, bulk density, particle-size distribution, moisture, stickiness, abrasiveness, friability and contamination sensitivity. These influence pickup, flowability, plugging, wear, degradation, filtration and regime suitability. Where material condition varies, record the expected range rather than one convenient sample.

3 — Bulk Density Is Not Particle Density

Bulk density includes voids between particles; particle or true density describes the solid material. Do not substitute one for the other. Bulk density supports throughput and feeder context but does not independently determine conveying gas demand.

4 — Particle Size Distribution

Record more than a nominal size where relevant. Fines can increase dust and filtration burden; coarse or irregular particles can affect pickup and impact; broad distributions can segregate. Record lumps, fibres, flakes and fragile agglomerates. Do not convert sieve data into a universal conveying velocity.

5 — Moisture, Stickiness and Flowability

Moisture can change cohesion, wall adhesion, feeder behaviour and plugging risk. Record normal and adverse material condition. If flowability tests, moisture limits or supplier handling instructions exist, attach them rather than replacing them with a generic free-flowing label.

6 — Abrasiveness and Friability

Abrasive solids can wear bends, diverters and pipe walls; fragile solids can degrade through impact and excessive velocity. Record wear history, breakage complaints and product-integrity requirements.

7 — Throughput Is a Duty Envelope

State normal, peak and future solids throughput with time basis. For batch systems record batch mass, fill time, conveying time, reset time and batches per hour. For continuous systems identify sustained rate and credible transient cases. A requirement such as 10 t/h is a solids requirement, not an airflow answer.

8 — Normal, Peak, Startup and Recovery

Build cases for normal production, highest legitimate rate, startup, cleanout or purge where applicable, future capacity and defined recovery. Do not create an artificial worst case by adding maxima that cannot occur together.

9 — Conveying Architecture

Identify positive pressure, vacuum, combined pressure-vacuum or undecided. Identify dilute phase, dense phase or unknown rather than forcing a regime before material and route evidence exist.

10 — Dilute and Dense Phase Boundaries

Actual regime selection depends on material behaviour, route, damage tolerance, pressure capability and specialist design.

11 — Route Register

Record actual horizontal runs, vertical rises and drops, bends, tees, diverters, flexible sections, feed elevation, discharge elevation and future extensions. State internal diameter and material by section where known. Do not reduce the route to straight-line distance.

12 — Bend Geometry

Record bend quantity, orientation, radius or type where known, especially in abrasive or fragile service. Existing systems should identify recurring wear locations. A route change adding several bends can require revalidation even if total length changes modestly.

13 — Feed Device

Identify rotary valve, venturi, screw, pressure vessel, blow tank or other feed mechanism. Record leakage, sealing, pressure-isolation and control information available from the supplier. The feeder can alter gas demand and pressure budget.

14 — Destination and Receiver

Record cyclone, filter receiver, silo, vessel, hopper or other destination; receiver pressure or vacuum; filter arrangement; and known backpressure. Consider filter differential pressure over operating condition, not only when clean.

15 — Gas Quality

Where conveying gas contacts product directly, define moisture, oil, particle and other contamination requirements from process risk. Do not assume generic plant air is suitable merely because it is compressed air.

16 — Temperature

Record gas and material temperature where it affects moisture, stickiness, softening, condensation, oxidation or quality. Temperature is a process variable when gas contacts material.

17 — Pressure and Flow Together

A valid air-mover interface is a pressure-flow requirement at a stated condition and connection point. Pressure without flow is incomplete; flow without pressure is incomplete. Compare a source only with a validated operating point or envelope.

18 — Flow Reference Basis

Gas velocity uses actual volumetric flow at local pressure and temperature. FAD, SCFM or another reference-state flow cannot be divided directly by pipe area unless it represents the same state. Preserve the reference basis on every flow value.

19 — Velocity Is Supporting Evidence

When local actual flow Q and internal diameter D are known, A = πD²/4 and v = Q/A report gas velocity at that condition. Suitability cannot be concluded from geometry alone; required transport velocity must come from qualified design, OEM data, pilot testing or validated operating evidence.

20 — Solids Loading Ratio

Where compatible solids mass flow and gas mass flow are already known, solids loading ratio can describe an operating condition. Do not reverse the relation to invent gas flow from an arbitrary target ratio.

21 — Pressure Budget

Required source pressure can be framed as conveying-line loss + feed/device loss + receiver backpressure + explicit margin. The conveying-line term is not equivalent to air-only friction. Solids loading, acceleration, bends, vertical movement and regime materially change the system.

22 — Compressor, Blower or Vacuum Equipment

Pneumatic conveying can use low-pressure blowers, higher-pressure compressors or vacuum equipment. Do not force every enquiry into a conventional plant-air compressor. Establish pressure-flow envelope, gas quality, control range and schedule first.

23 — Existing-System Diagnostic Mode

For low throughput collect solids rate, pressure trend, gas flow where available, feeder speed and filter differential pressure. For plugs record material condition, location, pressure before the event and sequence timing. For breakage or wear record velocity evidence, bend locations, pipe size and wear pattern.

24 — Capacity Increase

Do not translate a throughput increase directly into the same percentage increase in airflow or pressure. Record current and proposed throughput, route, pipe and material changes plus validated performance evidence.

25 — Worked Example: Capacity Increase

Increase = (9 − 6) / 6 × 100 = 50%. The conclusion is not increase air by 50%. The conveying duty requires revalidation because no validated conveying curve or airflow relationship has been supplied.

26 — Worked Example: Route Change

Record revised geometry and flag the prior pressure-flow selection for revalidation. Do not invent the new pressure drop from route change alone.

27 — Worked Example: Local Velocity Screen

Area = π × 0.100² / 4 = 0.00785 m²; flow = 4.0/60 = 0.0667 m³/s; gas velocity ≈ 8.5 m/s.

28 — Worked Example: Reference Flow Gate

Do not divide 8.0 by pipe area. Convert reference flow to actual local volumetric flow before local velocity is calculated.

29 — Temporary or Rental Air

Identify exact connection point, validated minimum flow at pressure, duty cycle, air quality, hose/manifold arrangement and whether temporary equipment replaces the normal air mover continuously or only supports a defined peak.

30 — Controls and Sequence

Record feeder start, air-mover start, line proving, receiver/filter readiness, normal stop, clearing where applicable and restart after interruption. Batch and dense-phase systems can have particularly important vessel and valve sequences.

31 — Instrumentation

Useful evidence can include source pressure, selected line pressures, vacuum, gas flow, feeder speed, receiver pressure, filter differential pressure, solids throughput and timestamps. State sensor location and reference basis.

32 — Supplier Design Boundary

Final pipe diameter, transport velocity, solids pressure loss, feeder selection, receiver/filter sizing, bend design and performance guarantee remain with the qualified method or supplier unless project evidence supports them.

33 — Bid Comparison

Normalize bids against the same material, throughput, route, schedule, gas quality and acceptance point. Reconcile FAD, inlet flow and actual conveying flow before comparison. Compare feeder, filter, receiver, controls, cooling, drying, pipework, electrical work and commissioning scope.

34 — Acceptance

Acceptance should demonstrate required solids throughput and product condition over defined cases while maintaining agreed pressure-flow, filtration, receiver and control behaviour. An empty-line air test is not proof of solids-conveying capacity.

35 — Failure to Convey Is Not Automatically Air Shortage

Changed material condition, feeder inconsistency, blocked filters, route obstruction, leakage, receiver backpressure, control sequence or unsuitable regime can cause conveying problems as well as inadequate gas supply. Preserve evidence before raising pressure or installing a larger compressor.

36 — Energy Boundary

Energy comparison begins only after the conveying duty is technically defined. Compare air-mover electrical input, compressor specific power where supported, control behaviour, unloading or turndown, filtration losses and operating schedule. Do not claim a saving by moving demand to a blower without including blower input.

37 — Future Expansion

Record future throughput, additional pickup points, route extensions, receiver changes and simultaneous duties separately. Do not hide future capacity inside an unexplained oversizing factor.

38 — Required Asset

The Pneumatic Conveying System Enquiry Specification captures material identity/properties; normal, peak and future throughput; architecture; regime; route; pipe; feeder; receiver/filter; validated pressure-flow where known; flow reference basis; air quality; sequence; instrumentation; evidence; acceptance criteria; supplier scope and exclusions.

39 — FAQ: Can tonnes per hour size the compressor?

No. Throughput alone does not define gas flow or pressure. Material, route, pipe, regime, feeder and receiver conditions also govern the duty.

40 — FAQ: Is there one correct conveying velocity?

No universal value is supported by the supplied foundation. Required transport velocity depends on material and conveying method and should come from specialist design, OEM guidance or validated testing.

41 — FAQ: Can FAD be used for pipe velocity?

Not directly unless its reference state matches the local pipe state. Convert the reference flow first.

42 — FAQ: Can an air-only pressure-drop formula size the solids line?

Not as final design. Solids loading and conveying behaviour materially change the pressure requirement.

43 — FAQ: What can approve?

It does not turn generic formulas into final pneumatic-conveying approval.

Pneumatic Conveying System Enquiry Specification

Enquiry Status Logic

Source Continuity

No universal dilute-phase velocity, dense-phase velocity, solids-loading target, final solids pressure-loss formula, compressor size, blower size or equipment rating has been introduced where the supplied material does not support one.

Expanded premium edition — engineering depth upgrade

The sections below deepen engineering substance without changing the controlled page identity, map intent or required asset.

Expanded Premium engineering core

The governing variables remain material behaviour, normal/peak/future throughput, conveying mode, route, pipe geometry, feeder, destination, air quality, operating sequence and validated pressure-flow evidence. Tonnes per hour alone is not an air-system specification.

Material characterisation in depth

Preserve product identity, bulk density, particle-size distribution, moisture/stickiness, abrasiveness and friability as separate inputs. Explain how each can alter pickup, plugging, wear, breakage, filter loading or feeder behaviour. Do not infer conveying velocity from particle size or bulk density. Record the source and revision of material data and distinguish measured values from supplier data and assumptions.

Route engineering

Build the route section by section: horizontal runs, vertical rise/drop, bends, tees, diverters, flexible sections, feed elevation, destination elevation and future extensions. Route changes are design changes.

Feeder and receiver boundaries

Expand the feeder discussion to include rotary valve, venturi, screw, blow tank/pressure vessel or other supplier-defined mechanisms, with leakage, sealing and pressure-isolation evidence. Expand the destination discussion to include cyclone/filter/silo/vessel condition, operating filter differential pressure and receiver backpressure. These boundaries materially affect the air-mover interface.

Flow-reference discipline

Local velocity uses actual volumetric flow at local pressure and temperature. Preserve gauge versus absolute pressure and every flow reference basis. This is a mandatory engineering guardrail, not an editorial note.

Pressure-budget boundary

Explain why air-only pipe-friction equations cannot be the final pressure-loss design for solids conveying. The complete requirement can include feed-device loss, solids pickup/acceleration, line behaviour, bends, vertical effects, receiver/filter backpressure and explicit design margin.

Existing-system diagnostics

Create a discriminating diagnostic method: low throughput requires solids rate, pressure trend, flow where available, feeder speed and filter DP; plugging requires material condition, plug location, pressure before event and sequence timing; wear requires abrasiveness, velocity evidence and bend map; high air use requires flow, leaks, feeder leakage, setpoint and duty cycle. Preserve evidence before multiple interventions.

Capacity and route change decisions

Keep the supplied 6-to-9 t/h example: solids throughput increases 50%, but airflow and pressure must not automatically increase 50%. Keep the route-change example of +25 m horizontal, +8 m vertical and four bends as a revalidation trigger rather than an invented pressure-drop result.

Worked calculations and interpretation

Retain the supplied local-velocity screen: 100 mm ID and 4.0 m3/min actual local gas flow gives area 0.00785 m2 and approximately 8.5 m/s. Explicitly label it geometry only. Add a second example showing why an 8.0 m3/min FAD value cannot be used as local actual flow without conversion. The educational value is the boundary, not a universal conveying setting.

Bid normalisation and supplier responsibility

Normalize bids to the same material, throughput, route, schedule, gas quality and acceptance point. Reconcile FAD, inlet and actual conveying flow. Compare feeder, filter, receiver, controls, silencers, cooling, drying, pipework, electrical work, commissioning and performance-guarantee exclusions.

Commissioning and acceptance

Acceptance must demonstrate required solids throughput and product condition over the defined duty while maintaining agreed pressure-flow, filtration, receiver and control behaviour. An empty-line air test does not prove solids capacity. Record material condition, route revision, instrument locations, flow basis and supplier evidence with the acceptance result.

Required asset — Expanded Pneumatic Conveying System Enquiry Specification

Expand the existing asset into a controlled record covering material identity/properties; throughput envelope; mode/regime; route; pipe; feeder; destination/filter; validated pressure-flow where known; flow basis; gas quality/temperature; operating sequence; simultaneous duties; instrumentation; supplier evidence; acceptance; scope/exclusions; assumptions and open items.