Steam Boiler Blowdown Rate (TDS Balance) & Flash Steam Recovery Calculator

Compute boiler TDS blowdown rate (lb/hr) and flash steam energy recovery.

Required Continuous Blowdown Flow
957.45 lb/hr
Blowdown Percentage of Steam Flow 6.38 %
Total Boiler Feedwater Required 15,957.45 lb/hr
Boiler Cycles of Concentration 16.67 cycles
Inputs
⚡ Scenarios:
lb/hr
Boiler steam generation rate in lb/hr.
ppm
Boiler feedwater / make-up Total Dissolved Solids (ppm).
ppm
Maximum allowable boiler drum TDS concentration (ppm).
Results & Graph
Required Continuous Blowdown Flow
957.45 lb/hr
Blowdown Percentage of Steam Flow
6.38 %
Total Boiler Feedwater Required
15,957.45 lb/hr
Boiler Cycles of Concentration
16.67 cycles

Required Continuous Blowdown Flow

Graph 1 • Boiler Blowdown & Flash Steam • Domain Architecture & Live Telemetry Maps Steam Generation Rate Lb Hr, Feedwater Tds Ppm, Max Allowable Boiler Tds Ppm through Boiler Blowdown & Flash Steam Formula.
INPUT PARAMETERS • Steam Generation R: 15000 lb/hr • Feedwater Tds Ppm: 180 ppm • Max Allowable Boil: 3000 ppm ∑ F(x) Boiler Blowdown & Flash St DESIGN OUTPUT 957.45 lb/hr Blowdown Percentage of S: 6.38 % Total Boiler Feedwater R: 15,957.45 lb/hr
Graph 2 • Required Continuous Blowdown Flow Across Steam Generation Rate Lb Hr Sweep (40% → 160%) Evaluates Blowdown% = [ Feedwater_TDS / (Allowable_Boiler_TDS − Feedwater_TDS) ] × across 7 operating points (current input highlighted).
0 lb/hr 842.6 lb/hr 1.7k lb/hr 383.0 6.0klb/hr 574.5 9.0klb/hr 766.0 12.0klb/hr 957.5 15.0klb/hr 1.1k 18.0klb/hr 1.3k 21.0klb/hr 1.5k 24.0klb/hr
Graph 3 • Joint Sensitivity: Steam Generation Rate Lb Hr × Feedwater Tds Ppm Compares Required Continuous Blowdown Flow when Feedwater Tds Ppm is shifted +25% (solid) vs. −25% (dashed).
0 lb/hr 869.6 lb/hr 1.7k lb/hr --- Feedwater Tds Ppm @ 75% 851.4 -30% 1.0k -15% 1.2k +0% 1.4k +15% 1.6k +30%
Summary: With 180 ppm feedwater and a 3000 ppm drum limit (16.7 cycles), blowdown is 6.38% of steam load = 957 lb/hr (total feedwater 15957 lb/hr).
Summary: With 180 ppm feedwater and a 3000 ppm drum limit (16.7 cycles), blowdown is 6.38% of steam load = 957 lb/hr (total feedwater 15957 lb/hr).
⚡ Send result to: Concrete & Sq Ft →Ohm's Law & Voltage Drop →Roofing, Stairs & BTU →
Interactive chart & math engine powered by CalculatorGraph

Formula & Mathematical Methodology: Boiler Blowdown & Flash Steam Formula

Blowdown% = [ FeedwaterTDS / (AllowableBoilerTDS − FeedwaterTDS) ] × 100
Blowdown% = [ Feedwater_TDS / (Allowable_Boiler_TDS − Feedwater_TDS) ] × 100
  • steamGenerationRateLbHr: Steam Generation Rate Lb Hr (lb/hr)
  • feedwaterTdsPpm: Feedwater Tds Ppm (ppm)
  • maxAllowableBoilerTdsPpm: Max Allowable Boiler Tds Ppm (ppm)

Rounding: Engineering outputs round to 2–3 decimal places; discrete material bag/unit counts round up via ceiling.

Worked Example: Engineering Scenario: Boiler Blowdown & Flash Steam

Compute boiler TDS blowdown rate (lb/hr) and flash steam energy recovery.

  1. Enter your system dimensions, electrical/RF ratings, or environmental conditions.
  2. Evaluate the governing equation: Blowdown% = [ Feedwater_TDS / (Allowable_Boiler_TDS − Feedwater_TDS) ] × 100.
  3. Inspect the primary design output, supporting allowances, and 3 SVG schematics.
Result: Computes Boiler Blowdown & Flash Steam via Blowdown% = [ Feedwater_TDS / (Allowable_Boiler_TDS − Feedwater_TDS) ] × 100.

Frequently Asked Questions

How does the Steam Boiler Blowdown Rate (TDS Balance) & Flash Steam Recovery Calculator calculate results?

It evaluates Blowdown% = [ Feedwater_TDS / (Allowable_Boiler_TDS − Feedwater_TDS) ] × 100 directly in your browser and updates three custom SVG visualizations in real time.

Can I use Goal Seek to solve backwards for a required dimension or rating?

Yes. Click "🎯 Goal Seek" in the results toolbar to solve backwards for any numeric input parameter.

Does this engineering calculator work offline?

Yes. All calculations run 100% locally in your browser and work offline via the CalculatorGraph PWA.

Science & Engineering · Thermodynamics & HVAC Systems

Steam Boiler Blowdown Rate (TDS Balance) & Flash Steam Recovery Calculator: inputs, method, and how to read the result

Compute boiler TDS blowdown rate (lb/hr) and flash steam energy recovery.

Choose inputs for the case you are checking

The defaults are illustrative. Replace them with values for your case and keep the units shown beside each field.

  • Steam Generation Rate Lb Hr: Boiler steam generation rate in lb/hr.
  • Feedwater Tds Ppm: Boiler feedwater / make-up Total Dissolved Solids (ppm).
  • Max Allowable Boiler Tds Ppm: Maximum allowable boiler drum TDS concentration (ppm).

What the calculation includes

With the default values shown, Required Continuous Blowdown Flow is 957.45 lb/hr. The calculation follows Boiler Blowdown & Flash Steam Formula; the formula and variable definitions above show how the inputs combine.

One-input check: With the other defaults held constant, changing Steam Generation Rate Lb Hr from 15,000 lb/hr to 16,500 lb/hr changes Required Continuous Blowdown Flow from 957.45 lb/hr to 1,053.19 lb/hr. This is a comparison inside the calculator's stated model, not a prediction.

Where to use caution

  • Uses standard NREL, IEEE, ASHRAE, and IRC design equations.
  • Verify final structural, electrical, and mechanical specifications against local building codes.

Scope: Global Engineering & Building Code Standard Check the assumptions and limitations against your situation before relying on the estimate.

More in Science & Engineering: Concrete & Square Footage Calculator, Ohm's Law, Wire Voltage Drop & Resistor Series/Parallel Calculator, Roofing, Stair Stringer, Tile, Mulch/Gravel & HVAC BTU Calculator.