Pulp Consistency Calculator

Calculate pulp stock consistency from fiber weight and slurry weight. Determine dilution water needed and fiber flow rates for paper machine approach systems.

Inputs

Dry fiber weight (kg)

Total slurry weight (kg)

Target consistency (%)

Flow rate (L/min)

Tab to move between fields

Results

Current consistency (%)

Water weight (kg)950

Target slurry weight (kg)5,000

Water change (L)4,000

Fiber flow (kg/min)25.63

Fiber flow (t/day)36.9

Consistency category2

Est. wire retention (%)95

How to Use This Calculator

Enter the oven-dry fiber weight (kg) in your stock sample or batch.
Input the total slurry weight (kg) including fiber and water.
Set the target consistency (%) for the next process stage.
Enter the stock flow rate (L/min) to calculate fiber throughput.
Review Current Consistency (%), Water Change needed (L), Fiber Flow (kg/min and t/day), and Consistency Category.

How the result changes with Total slurry weight (kg)

Total slurry weight (kg)	Current consistency (%)
100,000	0.05
350,000	0.01
650,000	0.01
900,000	0.01

What each input means

Dry fiber weight (kg): Oven-dry weight of fiber in the stock sample or batch (kg).
Total slurry weight (kg): Total weight of the fiber + water slurry (kg).
Target consistency (%): Desired consistency for the next process stage.
Flow rate (L/min): Stock flow rate for calculating fiber throughput.

What each result means

Current consistency (%): Current fiber consistency as percentage of total slurry weight.
Water weight (kg): Weight of water in the current slurry.
Target slurry weight (kg): Total slurry weight needed to achieve target consistency with the same fiber.
Water change (L): Water to add (positive) or remove (negative) to reach target consistency.
Fiber flow (kg/min): Bone-dry fiber mass flow rate at current consistency and flow rate.
Fiber flow (t/day): Fiber throughput in metric tons per day.
Consistency category: 0 = White water, 1 = Approach/headbox, 2 = Thick stock, 3 = Medium, 4 = High.
Est. wire retention (%): Estimated first-pass retention on the paper machine wire.

How this is calculated

Worked example, using the default values

Identify Input Parameters
4 parameters
Dry fiber weight (kg) = 50, Total slurry weight (kg) = 1000, Target consistency (%) = 1, Flow rate (L/min) = 500 = 4 input(s) provided
Calculate Current consistency
Current consistency = (dryFiberKg / totalSlurryKg) * 100
5 = 5
Calculate Water weight
Water weight = totalSlurryKg - dryFiberKg
950 = 950
Calculate Target slurry weight
Target slurry weight = targetConsistencyPct > 0
5000 = 5000

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