Description
Return expandedDepth = settledDepth*(1+suppliedExpansionFraction) and clearance = vesselHeight-reservedHeadspace-expandedDepth.
Nominal hydraulic ratios connect flow to area, length, volume or travel time. These local terms depend on active geometry and steady conditions; they do not describe a full distribution of velocities, residence times or treatment performance.
Return expandedDepth = settledDepth*(1+suppliedExpansionFraction) and clearance = vesselHeight-reservedHeadspace-expandedDepth.
When to use this tool
Use Filter BED Expansion Clearance when checking one supplied hydraulic loading, clearance, volume or travel-time term.
How to use the tool and how it works
- Enter settledDepth, suppliedExpansionFraction, vesselHeight, reservedHeadspace. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read expandedDepth, clearance. Use the output convention below.
Require nonnegative settledDepth, suppliedExpansionFraction, vesselHeight and reservedHeadspace. Return expandedDepth = settledDepth*(1+suppliedExpansionFraction) and clearance = vesselHeight-reservedHeadspace-expandedDepth. All lengths share one unit; the expansion fraction is relative extra depth rather than a final depth multiplier.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| settledDepth | Settled Depth | Required. Finite number; minimum 0. |
| suppliedExpansionFraction | Supplied Expansion Fraction Unit: 1. | Required. Finite number; minimum 0. |
| vesselHeight | Vessel Height | Required. Finite number; minimum 0. |
| reservedHeadspace | Reserved Headspace | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| expandedDepth | Expanded Depth | Required. Finite number. |
| clearance | Clearance | Required. Finite number. |
{
"input": {
"settledDepth": 1,
"suppliedExpansionFraction": 0.5,
"vesselHeight": 2,
"reservedHeadspace": 0.2
},
"output": {
"expandedDepth": 1.5,
"clearance": 0.30000000000000004
}
}Limitations and assumptions
- Negative clearance signals that the ideal expanded bed exceeds the supplied available height; it is not clamped. Expansion is caller-supplied, with no media, flow, temperature or safe backwash model.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use a complete hydraulic and treatment model when changing flows, turbulence, media behavior or safety margins matter.
References
Similar or alternative tools
- Filter Backwash Expansion BED Height Term
Return expandedHeight = settledHeight*(1+expansionFraction), freeboard = vesselHeight-expandedHeight and fits = expandedHeight <= vesselHeight.
- Filter Back Wash Recovery Loss
Reconcile supplied backwash recovery volumes and identify an empty recovery denominator.