Compact Spinning Suction Airflow, Fan Power & Energy Cost

The formula

This is the expression the tool evaluates. Every term is named underneath, with the unit it must be supplied in.

How the result is derived

Step by step, from the values you type to the figure on screen.

1. The 10 inputs are read from the form on every keystroke: Spindles on the Frame, Airflow per Spindle, Suction Pressure, Fan Efficiency, Motor Efficiency, Delivery Speed, Yarn Linear Density, Machine Efficiency, Operating Hours and Energy Price.
2. Each value is checked against the accepted range in the input table below. A value outside its range stops the calculation rather than producing a misleading figure — the results blank out and a message appears.
3. The validated values are substituted into the expression above, which resolves Fan Electrical Power together with every supporting figure in one pass — no value is carried over from a previous entry.
4. The supporting outputs — Power per Spindle, Energy per Kilogram of Yarn, Compacting Cost per Kilogram, Total Airflow, Frame Production, Annual Energy, Annual Cost and Fan-and-Motor Efficiency — come from the same pass, so they always describe the same case as the headline figure.
5. Results are rounded for display only. The full-precision value is used throughout the chain, so reading a rounded intermediate figure back into the tool by hand can shift the last digit.

What each input means

Where to read each value on the floor, the unit it must be in, and the range the tool accepts.

What the tool returns

The headline figure and every supporting value it is built from.

Worked example

Substituting

Six-tenths of a cent per kilogram is the whole energy cost of compacting, against a hairiness reduction that typically cuts winding clearer cuts and sizing add-on measurably. Very few quality interventions in a spinning mill are this cheap - which is why the argument about compact spinning is about capital and maintenance, not about running cost.

How to use it

1. Work through the input groups in order — Suction System and Production & Tariff. The defaults are a realistic case, so you can change one value at a time and watch what moves.
2. There is no calculate button. Every figure recalculates as you type or drag, which is what makes this usable for a what-if sweep rather than a single answer.
3. Read Fan Electrical Power in the dark results panel — that is the headline figure, expressed in kW.
4. Check the supporting rows underneath (Power per Spindle, Energy per Kilogram of Yarn, Compacting Cost per Kilogram, Total Airflow, Frame Production, Annual Energy, Annual Cost and Fan-and-Motor Efficiency) before acting on the headline — they are where an implausible input usually shows itself first.
5. Reset to defaults returns every field to the reference case, which is the quickest way to check whether a surprising result came from the tool or from an input you had changed earlier.

Where this is used

• Process planning — establishing Fan Electrical Power before a trial is booked, so machine time and material in Spinning, Winding & Yarn Package Engineering are committed against a calculated figure rather than an estimate.
• Costing and quotation — Fan Electrical Power is an input to the cost sheet, and quoting from a worked number rather than a remembered one is what keeps a margin intact.
• Troubleshooting — when the floor result drifts from plan, entering the measured values (starting with Spindles on the Frame) shows how much of the gap in Fan Electrical Power each variable explains.
• Teaching and study — the accepted ranges bracket normal Spinning, Winding & Yarn Package Engineering practice, so moving one variable at a time shows the shape of the relationship rather than a single answer.

Reading the result

Typical bands and what each one is telling you.

Assumptions and limits

• The power calculation is the ideal fan law and assumes the stated pressure is the total the fan develops against the system. Real installations lose pressure in the ducting between fan and spindle, so the fan pressure entered should be the measured value at the fan rather than the design value at the spindle; using the latter understates the power substantially on a long frame. Fan efficiency is the aerodynamic efficiency at the actual operating point, not the peak on the fan curve - a fan running well off its best-efficiency point can be twenty points below its rating. Airflow per spindle is a design figure and assumes no leakage; a worn or damaged suction tube draws more air at less useful compacting. Energy costs here are compacting only and exclude the spindle drive, the drafting drive and the overhead cleaner.
• Every input is bounded to the range normal practice occupies (Spindles on the Frame 100 to 2000, Airflow per Spindle 0.2 to 6 m3/h and Suction Pressure 500 to 8000 Pa, and so on for the rest). Those bounds are guard rails against typing errors, not a claim that the formula fails one unit outside them.
• The calculation is deterministic: the same inputs always give the same result. It carries no allowance for machine condition, operator skill, ambient conditions or lot-to-lot material variation unless an input above explicitly represents one.
• Nothing is sent anywhere. The maths runs in your browser, so the numbers you type never leave the page.

Standards and further reading

• ISO 5801 - Fans, Performance testing using standardized airways, for the flow and pressure inputs.
• IEC 60034-30-1 - Efficiency classes of line-operated AC motors, for the motor efficiency.
• ISO 50001 - Energy management systems, for the energy performance indicator this feeds.
• ASTM D5647 - Measuring Hairiness of Yarns, for the property compacting is bought to improve.

Questions people ask