Cutter Suction Dredge Production and Slurry Density
Turns pipeline flow and solids concentration into in-situ production and the specific gravity the discharge density...
Example
You enter
- Discharge pipe inside diameter (in) 24
- Pipeline velocity (ft/s) 18
- Solids concentration by volume (%) 15
- In-situ porosity (0 to 1) 0.4
- Solids specific gravity 2.65
- Effective dredging hours per day 20
- Alternative concentration (%) 20
You get
- Area (ft²) 3.14159
- Pipeline flow 56.55 cu ft/s through 3.142 sq ft
- Solids the pipeline carries 8.48 cu ft/s -- 1131 cy/h of particles
- In situ (cfs) 14.1372
- In-situ production 1885 cy/h
- Production per day 37699 cy over the entered effective hours
- Solids cy per (hr) 1130.97
- Density gauge should read 1.248 specific gravity
- At the alternative concentration 2513 cy/h, 628 more (33%) at gauge 1.330
- Alternative gain (%) 33.3333
Details, formula, and sources
Turns pipeline flow and solids concentration into in-situ production and the specific gravity the discharge density gauge should read. The worked 24 in line at 15% solids makes 1,885 cy/h, of which 754 cy/h is the void space the sand had in the bank and is paid for. Contract porosity and effective-hour accounting govern.
flow = pipe area x velocity; solids = flow x Cv; in-situ = solids / (1 - porosity); production in cy/h = in-situ cu ft/s x 3,600 / 27; slurry SG = 1 + Cv (SG_solids - 1).
Continuity and volumetric bookkeeping. The pay quantity, the in-situ porosity assumed, and effective-hour accounting come from the dredging contract and the site's own material.
Public relations; no purchased standard is required to reproduce them.
Estimate. AHJ and licensed professional govern.
Field names used by the API: pipe_diameter_in, velocity_fps, concentration_pct, porosity, solids_specific_gravity, effective_hours, alternative_concentration_pct, area_ft2, flow_cfs, solids_cfs, in_situ_cfs, production_cy_per_hr, production_cy_per_day, solids_cy_per_hr, slurry_specific_gravity, alternative_production_cy_per_hr, alternative_gain_pct
- Porosity entered; about 0.35 to 0.45 for sand, and a contract term rather than a measurementdredging contract
- Effective hours dredging hours only -- swing, anchor moves, and pipeline changes are not dredgingproduction accounting