Calculate one packed absorber packing depth from a source-owned, basis-matched HTU and NTU pair or an explicitly bounded EPA simplified gas ratio, with optional same-condition reconciliation.
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A quick decision brief for this specific tool
Inputs that matter
One de-identified completed packed-absorber source case; record type, source ID/revision, solute/gas identity, solvent condition, packing identity/arrangement, operating-condition and one-case applicability records, completion time, reviewer/review time and retention record; direct source-reported or EPA simplified gas-ratio mode; exact overall-gas, overall-liquid, gas-film or liquid-film transfer-unit basis; positive HTU in metres or feet and its empirical/pilot/vendor/source applicability; either a positive same-basis source-reported NTU and source, or same-basis positive inlet/outlet gas values with outlet below inlet plus concentration basis/source and four explicit EPA simplification boundaries; four refusal boundaries; plus optional all-or-none independent depth, unit, source and reviewer-owned same-condition match record
Output to expect
One source-case packing depth in the entered HTU unit plus normalized metres and feet; retained transfer-unit basis, HTU and NTU; for simplified mode only, inlet/outlet ratio and arithmetic removal percentage; and optional calculated-minus-independent signed metric depth difference without pass/fail
How it works
Validate the complete source-case identity and four refusal boundaries; require HTU and NTU to share one declared transfer-unit basis; multiply source-reported HTU×NTU directly, or require overall-gas basis plus all steady-state/dilute, Henry-law/linear-line, negligible-entering-liquid-solute and negligible-reciprocal-absorption-factor records before deriving NOG = ln(inlet/outlet); convert only with the exact international-foot factor; require all four independent fields and compare after the reviewer owns the same system, solvent, packing, flows, properties and basis; preserve six nondecisions and versioned Project outputs
Confirm the exact source/revision, solute and carrier-gas composition, solvent identity/condition, packing type/size/material/arrangement, gas and liquid rates, temperature, pressure, physical properties and transfer-unit basis. Another system, packing, flow, property set, basis or source revision needs another record.
Treat HTU as source-owned empirical, pilot, vendor or completed-design evidence. Do not mix HOG with NOL/NG/NL, transfer one packing or flow case to another, or call HTU×NTU total vessel height; distributors, supports, demisters, disengagement space, nozzles and access remain external.
Use NOG = ln(inlet/outlet) only when the source record supports steady-state dilute operation, Henry-law linear equilibrium and operating lines, negligible solute in entering liquid, and negligible reciprocal absorption factor. A target removal percentage alone does not prove those assumptions.
Use the result only as one packing-depth arithmetic record. It does not size diameter, flooding, wetting, pressure drop, distribution, utilities or internals; predict mass-transfer coefficients or equilibrium; guarantee removal; select solvent, packing or materials; decide corrosion, toxicity, fire, exposure or process safety; or authorize scale-up, compliance, detailed engineering, fabrication, commissioning or acceptance.
Choose your path
Built around the job you need to finish
Calculate one source-case packed absorber packing depth from a basis-matched HTU/NTU pair or an explicitly bounded EPA simplified overall-gas ratio, optionally reconcile one independent same-condition depth, and refuse every total-vessel-height, sizing, performance, safety, compliance and acceptance decision.
Process-design record technician retaining one completed absorber case
Preserve the exact HTU/NTU basis, system, solvent, packing, flows and source revision without presenting one arithmetic product as a complete tower design.
Identify one de-identified completed source case, copy its matched empirical HTU and NTU evidence, calculate packing depth, review the explicit scope and retain a snapshot.
Can hand off a reproducible packing-depth record while total vessel height, diameter, hydraulics, internals, utilities and professional approval remain with accountable design records.
Environmental engineer reviewing a simplified gas-ratio estimate
Use the EPA concentration-ratio shortcut only when its dilute, linear-equilibrium, clean-entering-liquid and high-absorption-factor assumptions are actually owned by the source case.
Choose simplified mode, preserve overall-gas basis, enter same-basis inlet/outlet values and their source, keep all four approximation boundaries, then inspect NOG, depth and the nondecision list.
Gets transparent conditional arithmetic without turning a target removal percentage into a guarantee, permit conclusion or uncontrolled scale-up.
Demonstrate why HOG/NOG, HOL/NOL, HG/NG and HL/NL pairs cannot be mixed and why packing depth differs from total tower height.
Load the training case, exercise all direct bases, switch modes to verify incompatible-field clearing, trigger assumption and same-condition errors, and compare an independent foot-based depth.
Learners can reproduce the arithmetic, name every source-dependent boundary and avoid treating this Tool as mass-transfer correlation, hydraulic sizing or safety software.
Authoritative checks for this tool
Outputs and checklists are planning aids. Review the linked current authorities and the records, terms, instructions, and requirements that apply to your exact situation before a consequential decision.
Identify one solute/gas system, solvent condition, packing arrangement, operating-condition set and source revision. HTU and NTU must both be overall-gas, overall-liquid, gas-film or liquid-film values from that same applicable case; the Tool does not predict or validate either source value.
Calculate packing depth under an explicit method
Direct mode uses Z = HTU × NTU. EPA simplified mode is limited to overall-gas HOG/NOG and derives NOG = ln(inlet/outlet) only when the record owns steady-state dilute operation, Henry-law linear equilibrium and operating lines, negligible solute in entering liquid and negligible reciprocal absorption factor.
Normalize and reconcile without approving a design
Packing depth is shown in the entered unit, metres and feet using the exact international-foot relationship. An optional independent depth is normalized and compared only after the reviewer records the same system, solvent, packing, flows, properties and basis; the signed difference is not a pass/fail result.
Updated: September 2026
Example Scenarios
A process-design technician retains one empirical or vendor HOG and matching NOG with exact system, packing, flow and revision evidence, then hands off a reproducible packing-depth record rather than a total vessel height.
An environmental engineer uses inlet and outlet gas values only after recording every EPA shortcut assumption, then treats the result as conditional arithmetic rather than a removal guarantee or permit conclusion.
An instructor demonstrates why HOG/NOG, HOL/NOL, HG/NG and HL/NL pairs cannot be mixed and why packing depth excludes distributors, supports, demisters, disengagement space and access allowances.
Common Mistakes to Avoid
✕
Mixing an HTU and NTU from different bases or cases
✓
Confirm both values share the exact overall/film and gas/liquid basis and apply to the same solute, solvent, packing, flows, temperature, pressure and property set. Unit conversion cannot repair a basis or applicability mismatch.
✕
Turning target removal directly into NTU or calling the result total tower height
✓
The logarithmic shortcut requires all four recorded EPA assumptions and an overall-gas basis. Its product with HOG is packing depth only; vessel internals, hydraulics, utilities, materials and safety require separate accountable design work.
FAQ
No. Z = HTU × NTU is retained as packing depth for one source case. Distributors, redistributors, packing supports, demisters, disengagement space, nozzles, heads, access and other mechanical allowances remain external.
Copy it from the source calculation or report. HOG must pair with NOG, HOL with NOL, HG with NG and HL with NL. The Tool rejects the simplified concentration-ratio mode unless the basis is overall gas.
Only when the source record supports steady-state dilute operation, Henry-law linear equilibrium and operating lines, negligible solute in entering liquid, and negligible reciprocal absorption factor. A target removal percentage by itself does not establish these conditions.
From an accountable empirical, pilot, vendor or completed design-basis source for the exact system, packing and operating case. This Tool preserves the source and applicability text but does not calculate mass-transfer coefficients or validate vendor data.
No. Diameter, flooding, wetting, pressure drop, liquid distribution, utilities, solvent and packing selection, corrosion, materials, hazards, emissions performance, process safety, detailed engineering and approval all require separate responsible evidence.
About Packed Absorber Depth Record
This Tool creates a method- and source-bound packed absorber packing-depth record. It multiplies one matched HTU/NTU pair or uses a narrowly bounded EPA gas-ratio simplification; it does not calculate total vessel height, hydraulic capacity, performance guarantees, materials, safety, compliance or final design.
