The Nathan injector uses successive steam jets to move water toward a boiler, with overflow control coordinated with steam admission. Explore the flow path and calculate mass-flow ratios and water volume from entered flows; delivery pressure and injector capacity require a separate performance model.
Injector Mass-Flow and Water-Volume Calculator
Enter declared water mass flow, condensing-steam mass flow, water density and a time interval. The worksheet reports arithmetic ratios and volumes only. It does not predict pickup, delivery pressure, capacity, temperature limits or safe boiler operation.
Equation Used
- Water and steam mass-flow entries are declared inputs, not predicted capacities.
- The combined-mass result assumes the entered steam flow fully condenses.
- Water density is user-entered and used only for volume conversion.
- Cone geometry, steam state, water temperature, lift, losses, valve timing, delivery pressure, boiler compatibility, controls and safety are excluded.
Water and steam flows are inputs to this calculation, not predicted capacities. The animation shows their paths schematically; particle speeds do not represent calculated fluid velocities.
Successive steam impulses and coordinated overflow control
Nathan Manufacturing assignee patent US574985A describes water being forced toward the boiler by successive impulses from two or more steam jets. It also coordinates the final overflow with the valve admitting operating steam.
The schematic shows the connected passages; cone dimensions, valve timing and delivery performance are not calculated.
Steam jets for boiler feedwater
Nathan patents document injectors for feeding water into boilers under pressure and specifically discuss locomotive installations. The mass-flow calculation does not rate a particular Nathan model or establish its suitability for a boiler.
Mass-flow and volume calculations
These identities do not calculate jet velocity, delivery pressure, hydraulic power or injector capacity.
Example using entered flows
For 2.00 kg/s water, 0.15 kg/s condensing steam, water density 998 kg/m³ and ten minutes, the declared water/steam ratio is 13.33:1, combined mass is 2.150 kg/s, water volume rate is 2.004 L/s and water volume over the interval is 1,202.4 L.
What a delivery-pressure calculation would require
Delivery depends on staged momentum exchange, steam condensation and pressure recovery through the injector passages. Adding mass flows alone cannot determine whether the injector will pick up water or deliver against boiler pressure. Those questions require geometry, steam and water conditions, and a performance model for the particular injector.
Nathan injector questions
Does this calculation prove delivery into a boiler?
No.
Why show two steam stages?
US574985A explicitly describes successive impulses from two or more steam jets.
Does the combined mass assume complete condensation?
Yes. The combined-mass result assumes complete condensation; the calculator does not predict whether that condition will occur.
Nathan injector references
- US574985A, Injector: primary Nathan Manufacturing assignee patent describing adjustable capacity, successive steam-jet impulses and coordinated final-overflow control.
- US1787432A, Operating mechanism for injectors: primary Nathan Manufacturing assignee patent describing locomotive non-lifting injector water and steam operation.
- Locomotive Engine Running and Management: period text containing a dedicated Nathan Manufacturing Monitor Injector section.
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