Route: /engineering-tools/pneumatic-conveying-enquiry-calculator/ (proposed until route reconciliation). It does not claim to replace specialist solids-conveying design, pilot testing or supplier performance calculations.

1. Purpose and Engineering Decision

Pneumatic conveying uses moving air or gas to transport bulk solids through a pipeline. The air-supply requirement depends not only on line length and pipe diameter but also on material behaviour, solids loading, conveying regime, pick-up conditions, vertical lift, bends, feeder arrangement, destination pressure, filtration and operating sequence.

Its job is to establish a technically usable duty brief, identify missing information, calculate simple supporting quantities and prevent a compressor or blower from being selected from an incomplete 'CFM only' request.

Enquiry mode	Primary output
New system	Complete conveying-duty enquiry brief
Existing system problem	Measured duty + restriction / pressure-loss evidence
Capacity increase	Current vs future throughput comparison
Temporary conveying	Required pressure/flow interface for rental assessment
Vendor bid comparison	Normalized input register before specialist design

2. Required Asset - Conveying Duty Enquiry Worksheet

Input group	Field	Why it matters
Material	Product / grade / composition	Flow behaviour and contamination risk
Material	Bulk density	Solids loading / throughput context
Material	Particle size distribution	Pickup, saltation and wear behaviour
Material	Moisture / stickiness	Plugging and flowability risk
Material	Abrasiveness / friability	Pipe wear and product damage
Process	Required solids throughput	kg/h or t/h
Process	Normal / peak / future throughput	Duty envelope
Mode	Pressure / vacuum / combined	Defines air-mover architecture
Regime	Dilute / dense / unknown	Specialist design basis
Route	Horizontal equivalent length	Pressure-loss driver
Route	Vertical lift / drop	Additional duty
Route	Bends / tees / diverters	Pressure loss / wear
Pipe	Internal diameter / material	Velocity and wear basis
Feed	Rotary valve / venturi / pressure vessel / other	Air leakage and pressure isolation
Discharge	Receiver / filter / cyclone / silo pressure	Backpressure boundary
Air	Available pressure / vacuum	At conveying equipment interface
Air	Available flow basis	FAD / SCFM / actual etc.
Quality	Dryness / oil / contamination limits	Process and product requirement
Operation	Continuous / batch / intermittent	Demand profile

3. Conveying Mode

Mode	Typical enquiry question
Positive-pressure conveying	What pressure and flow are required from compressor/blower to move the solids to destination?
Vacuum conveying	What suction flow, vacuum level and separator/filter arrangement are required?
Pressure-vacuum combined	What are the pickup and discharge interfaces and where is air admitted/removed?
Dense-phase / low-velocity	Is material suitable and is a specialist pressure-vessel / control sequence defined?
Dilute-phase / higher-velocity	What transport velocity and solids-loading basis is required by the conveying specialist?

4. Throughput Is a Solids Requirement, Not an Airflow Answer

Solids Throughput = Mass Conveyed / Time

A requirement such as 10 t/h is not enough to determine compressed-air demand by itself. The same solids throughput can require very different air flow and pressure depending on product density, line diameter, conveying regime, route and allowable product velocity.

5. Simple Solids Loading Ratio - Optional Screening

Solids Loading Ratio = Solids Mass Flow / Gas Mass Flow

This dimensionless ratio can be useful when gas mass flow is already known from a supplier or test.

6. Pipeline Route Register

Route item	Required entry
Straight horizontal run	Actual length by section
Vertical rise	Height and direction
Vertical drop	Height and direction
Long-radius bends	Quantity and radius if known
Short bends / elbows	Quantity
Tees / diverter valves	Quantity and type
Flexible hose	Length + internal diameter
Feed point	Elevation / pressure condition
Discharge point	Elevation / receiver pressure

7. Air Velocity - Supporting Calculation Only

Gas Velocity = Actual Volumetric Flow / Pipe Cross-Sectional Area

Pipe Area = pi x D_internal^2 / 4

Velocity must use actual volumetric flow at the local line pressure and temperature, not an unconverted FAD or standard-flow number.

Required transport velocity depends on the material and conveying regime and should come from specialist design data, OEM guidance or validated testing.

8. Pressure Budget

The air mover must overcome the complete conveying-system resistance, not merely the straight pipe. The enquiry therefore separates feed-device loss, acceleration/pickup loss, straight-line friction, bends, vertical lift effects, receiver/filter backpressure and any terminal equipment.

Required Supply Pressure = Conveying Line Loss + Feed/Device Loss + Receiver Backpressure + Explicit Margin

9. Existing System Diagnostic Mode

Symptom	Evidence to collect
Throughput below target	Actual t/h, pressure trend, air flow, feeder speed, filter DP
Pipeline plugs	Material condition, location of plugs, line pressure before event, sequence timing
Excessive product breakage	Velocity, bend locations, pipe diameter, material friability
High pipe wear	Material abrasiveness, velocity, bend geometry, wear map
High air consumption	Measured flow, leaks, feeder leakage, pressure setpoint, duty cycle
Unstable conveying	Pressure pulsation, feeder consistency, filter condition, receiver pressure

10. Air Quality and Material Compatibility

Compressed air can contact the conveyed product directly. Where product contamination matters, the enquiry must define acceptable moisture, oil, particles and other contamination rather than treating air quality as a generic accessory.

The supplied Reddy Compressors engineering material explicitly uses pneumatic conveying as an example where pressure and flow must be considered together, and it also notes that product-contact risk should determine the required air-quality strategy.

11. Worked Validation Case A - Geometry / Velocity Screen

Synthetic validation case: 100 mm internal-diameter conveying line with 4.0 m3/min actual gas flow at the selected local condition.

A = pi x 0.100^2 / 4 = 0.00785 m2

v = 0.0667 / 0.00785 = 8.5 m/s

Calculated gas velocity is approximately 8.5 m/s.

12. Worked Validation Case B - Reference Flow Must Be Converted

Synthetic test: supplier flow is stated as 8.0 m3/min FAD, while the local conveying-line pressure is above atmospheric pressure.

This prevents a common error where standard/reference flow is treated as the actual volumetric flow moving through the pressurised conveying pipe.

13. Worked Validation Case C - Capacity Increase

Synthetic test: current solids throughput is 6 t/h and proposed throughput is 9 t/h. No validated conveying curve, solids-loading basis or measured airflow is supplied.

Throughput Increase = (9 - 6) / 6 x 100 = 50%

It does not assume that airflow or pressure must also increase by exactly 50%.

14. Worked Validation Case D - Route Change

Synthetic test: an existing conveying route gains 25 m horizontal pipe, 8 m vertical lift and four additional bends.

It does not invent the new pressure drop without a validated pneumatic-conveying method.

15. Temporary / Rental Air Interface

For temporary compressed-air support, the enquiry must identify the exact connection point, minimum flow at pressure, expected duty cycle, air quality, hose/manifold arrangement and whether the rental compressor is replacing a blower/compressor continuously or only supporting a peak.

16. Compressor vs Blower Boundary

Pneumatic conveying can use low-pressure blowers, higher-pressure compressors or vacuum equipment depending on the duty. The required pressure-flow envelope should determine the air-mover technology.

17. Demand Profile

Duty case	Record
Normal	Typical throughput, flow and pressure
Peak	Highest legitimate solids rate / simultaneous feed
Startup	Line empty/full, feeder start sequence
Cleanout	Air-only purge or line clearing if applicable
Future	Planned capacity increase
Fault / recovery	Plug-clear or restart requirement if defined

18. Input Model

Input group	Field	Validation
Material	Bulk density	> 0 if used
Material	Particle size / moisture / abrasiveness	Required descriptive fields
Process	Throughput	> 0
Mode	Pressure / vacuum / regime	Required
Route	Horizontal / vertical lengths	>= 0
Route	Bend / diverter counts	>= 0
Pipe	Internal diameter	> 0
Air	Pressure / vacuum basis	Required
Air	Flow + reference basis	Required when known
Quality	Air contamination requirement	Required where product-contact relevant
Evidence	Supplier / pilot / existing system data	Required for final design acceptance

19. Validation and Guardrails

Condition	Required behaviour
Material identity missing	HOLD
Throughput missing	HOLD
Pipe diameter missing for velocity screen	Block velocity
Reference flow used as local actual flow	Block
Conveying regime unknown	Allow enquiry, HOLD design
Universal velocity entered with no source	Mark unverified
Pressure loss calculated from air-only pipe formula as final solids-conveying loss	Block final acceptance
Throughput scale-up assumed linear for air demand	Warn / HOLD
Product-contact air quality undefined	Warn / HOLD where relevant

20. PASS / HOLD / FAIL Logic

Status	Meaning
PASS - enquiry complete	Sufficient information exists to send for specialist/vendor design
HOLD - information gap	Material, route, flow basis or duty data missing
FAIL - candidate interface

Its highest native status is 'enquiry complete' unless validated specialist performance data is imported.

Pneumatic Conveying Enquiry Calculator

Use the working tool for this page