High-pressure test data: the evaluation begins with defined process conditions, material data and equipment boundaries. Material suppliers and plant engineers sometimes possess conveying data generated on a high-pressure test rig and ask whether it can be used to select a standard roots blower. The data may be informative, but it cannot be transferred directly when the proposed pressure gradient, feeder and flow regime are different.
The correct question is not whether the product was conveyed successfully at high pressure. It is whether the test includes a stable operating region inside the pressure and airflow envelope available to the proposed positive-pressure roots blower system.
Start with the Pressure-Source Boundary
Pasifik Blower publishes a positive-pressure two-lobe and three-lobe portfolio spanning approximately 30–9,360 m³/h and pressures up to 1,000 mbar across the complete range. These are portfolio limits, and each model has its own flow, speed, power and pressure envelope.
A test conducted at several bar gauge belongs to a different pressure-source and feeder architecture. It may demonstrate material behavior, but it does not prove that the same throughput or flow mode can be produced by a standard roots blower.
Compare Pressure Gradient, Not Only Test Pressure
The available pressure must be considered together with effective route length, bends, elevation, pipe bore, receiver resistance and feeder loss. A short test line can have a far greater pressure gradient than a long plant line even when both use the same nominal inlet pressure.
If low-velocity transport occurred only at a gradient unavailable in the proposed system, that portion of the curve should be excluded from roots blower selection. Extrapolating it downward can place the plant in an unstable transition or blockage region.
Check Whether the Feeding Method Can Be Reproduced
High-pressure trials often use sealed batch vessels with controlled fluidization or discharge. A low-pressure production line may use a rotary valve, screw feeder or another device with different leakage and feed stability.
Feeder behavior affects both the gas balance and the way material enters the pipeline. Data obtained with one feeding mechanism should not be treated as a guarantee for another. The proposed feeder must be evaluated at the actual pressure difference and material rate.
Identify the Portion of Data That Remains Useful
High-pressure results can still support screening. They may reveal:
- Whether the grade is sensitive to airflow changes.
- How particle damage develops with velocity.
- Whether pressure fluctuation increases near a transition.
- The effect of fines, moisture or repeated circulation.
- Relative differences between material grades tested in the same rig.
These observations guide the low-pressure trial plan, but the final duty should come from data within or close to the proposed roots blower operating region. The report should preserve the original axes, reference conditions and uncertainty so later reviewers can distinguish measured evidence from engineering interpretation.
Define a Low-Pressure Verification Test
The verification should reproduce the actual material grade, realistic feeder, representative pipe bore and a route that provides a defensible pressure gradient. It should measure airflow at a stated reference condition, solids throughput, total and section pressure, product condition and receiver-filter behavior.
Where a full-length test is impractical, the scale-up method and uncertainty allowance should be stated explicitly. The design point must remain above the observed stability boundary and below the selected model’s pressure, power and temperature limits.
Use the Result as a Go-or-No-Go Decision
If the required material duty cannot be demonstrated within the standard roots blower envelope, the project should not force a larger blower or claim high-pressure dense-phase performance. The conveying concept, line size, route, throughput or pressure-source technology requires separate engineering review.
This disciplined boundary protects the buyer from purchasing a blower that meets an air-volume figure but cannot reproduce the material conditions behind the original high-pressure test.
Glossary
Data transferability: Degree to which test results remain valid for another defined system and operating range.
Pressure-gradient mismatch: Difference between test and plant pressure available per effective unit of conveying route.
Scope boundary: Explicit limit separating the reviewed product or system from another technology.
Test-condition mismatch: Material, feeder, geometry or operating difference that prevents direct use of test results.