Solids Mass Flow (Dredge)
Calculate the mass flow of solids transported by a dredge or pipeline, ṁ_s = Q·C_v·ρ_s, from the total slurry flow Q (m³/s), the solids volumetric concentration C_v (fraction) and the solids density ρ_s (kg/m³). Solids mass flow is the MASS of useful material transported per unit time (kg/s, or tonnes per hour), the production indicator used when TONNAGE matters — the typical case of ore transport by pipeline (measured in t/h of dry ore) and mineral processing. It is the product of three factors: the slurry flow (pump capacity), the solids concentration (how 'loaded' the slurry is) and the solids density (iron ores, for example, are very dense, ~5000 kg/m³, so little volumetric concentration already gives high tonnage). Mass flow, integrated over time, gives the total transported tonnage, the basis of billing and operational mass balance. Optimizing it — maximizing tonnage per unit pumping energy — is the central goal of pipeline operation, which moves hundreds of millions of tonnes of ore per year over long distances far more energy-efficiently than trucks or trains. Enter the slurry flow, the volumetric concentration and the solids density.
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Solids mass flow (dredge)
The solids mass flow rate transported by a dredge or slurry pipeline is ṁ_s = Q·C_v·ρ_s, from the total slurry flow Q, the volumetric concentration C_v, and the solids density ρ_s. It is the mass of useful material transported per unit time (kg/s, or tonnes per hour), the production indicator used when what matters is tonnage — the typical case for ore transport through slurry pipelines (measured in t/h of dry ore) and for mineral processing. It is the product of three factors: the slurry flow rate (pump capacity), the solids concentration (how 'loaded' the slurry is), and the solids density (iron ores, for instance, are very dense, ~5000 kg/m³, so a modest volumetric concentration already yields a high tonnage). The mass flow rate, integrated over time, gives the total tonnage, the basis for billing and for the mass balance. Optimizing it — maximizing tonnage per unit of pumping energy — is the central goal of operating slurry pipelines, which move hundreds of millions of tonnes of ore per year over long distances with far better energy efficiency than trucks or trains. Enter the slurry flow rate, the volumetric concentration, and the solids density.
Related Tools
Dredge Solids Production
Calculate the volumetric solids production of a dredge or pipeline, Q_s = Q·C_v, from the total slurry flow Q (m³/s) and the solids volumetric concentration C_v (fraction). Solids production is the volume of useful material (sand, sediment, ore) effectively transported per unit time — the direct measure of dredging or slurry-pumping PRODUCTIVITY, and what really matters commercially (a dredge is paid per cubic metre dredged, not per pumped water). It is the product of the total slurry flow and the solids fraction: increasing production means increasing the flow (bigger pumps, more power) OR increasing the solids concentration (excavating denser material, optimizing the suction). There is a fundamental trade-off: pumping very concentrated slurry raises production per cubic metre of slurry but raises mixture density, head loss and deposition/clogging risk. Solids production, integrated over time, gives the total dredged volume (for measurement and payment) and frames planning (how many hours/days to dredge a channel, fill a pit, move overburden). It is the key operational indicator. Enter the slurry flow and the volumetric concentration.
Slurry Mass Concentration
Calculate the solids mass (weight) concentration in a slurry, C_w = C_v·(ρ_s ÷ ρ_m)·100, from the volumetric concentration C_v (fraction), the solids density ρ_s and the mixture density ρ_m (kg/m³); the result is a percentage. Mass concentration is the fraction of the total slurry MASS that is solid (kg of solid per kg of slurry), different from volumetric concentration (volume fraction). Both measure the same thing differently, and their relation depends on the solids density: since solids are DENSER than water (sand ~2.65×), mass concentration is always GREATER than volumetric (a slurry with 20% solids by volume has about 40% by mass). Mass concentration (% solids by weight) is the form most used in the mineral industry and ore processing, since it relates directly to the tonnage of solids processed and is what is controlled in thickeners, mills and flotation. Converting between mass and volumetric concentration is a daily operation in processing-plant mass balance and pipeline and dredging control. Enter the volumetric concentration, the solids density and the mixture density.
Critical Deposition Velocity (Durand)
Calculate the critical deposition velocity in hydraulic solids transport by Durand's equation, V_c = F_L·√(2·g·D·(s − 1)), from the Durand factor F_L (dimensionless, a function of grain size and concentration), the pipe inner diameter D (m) and the solids relative density s = ρ_s/ρ_w. Critical velocity is the MOST important parameter in designing pipelines and dredge discharge lines: it is the MINIMUM flow velocity below which solids start to DEPOSIT on the pipe bottom, forming a bed that reduces the section, raises head loss and can lead to total CLOGGING of the line (a very costly, slow accident to clear). Above the critical velocity, turbulence keeps the particles suspended and moving. Operation must keep the velocity ALWAYS above critical (with safety margin), but not too far above, since excessive velocities waste pumping energy and cause accelerated abrasive wear of pipe and pumps. Determining the critical velocity sets the operating velocity, the pipe diameter and the pumping power. Durand's correlation (1953), with the tabulated F_L factor, is the classic basis of this calculation. Enter the Durand factor, the pipe diameter and the solids relative density.
Refrigerant Mass Flow
Compute the refrigerant mass flow needed in a cycle, ṁ = refrigerating capacity / refrigerating effect, dividing the desired cooling load (kW) by the specific refrigerating effect (kJ/kg, the enthalpy absorbed per kilo at the evaporator). It is how much refrigerant must circulate per second to meet the demand — the basis for sizing the compressor, the piping and the system gas charge. Enter the refrigerating capacity and the refrigerating effect.
Landfill Methane Flow (Scholl Canyon)
Computes the methane flow generated by one batch of landfilled waste using the Scholl Canyon first-order decay model, Q = k × L₀ × M × e^(−k×t), where M is the mass of that batch, L₀ is the total methane potential per tonne, k is the annual decay constant and t is the age of the batch. The model assumes generation peaks right after placement and falls exponentially from then on, with k between 0.04 and 0.09 per year in wet climates and L₀ typically 50 to 170 m³ of methane per tonne of wet waste, 170 being the LandGEM default. Since the model is linear in mass, a real landfill is summed batch by batch, each with its own age. Enter the decay constant, the methane potential, the waste mass and the age of the batch.
Steam Turbine Power
Calculate the mechanical power generated by a steam turbine, P = ṁ × (h₁ − h₂), multiplying the steam mass flow (kg/s) by the enthalpy drop between turbine inlet and outlet (kJ/kg). The result, in kW, is the shaft power delivered to the generator, accounting for the expansion of high-pressure, high-temperature steam down to condenser pressure. It is the core calculation in sizing thermal power and cogeneration plants: the larger the enthalpy drop, the more power per kg of steam. Enter the steam flow and the inlet and outlet enthalpies.
The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.