Recent Blogs
Vertical Water Tube Boiler: Flow Animation and Assumption Calculator
Explore a water-tube circulation diagram and calculate flows from entered steam rate and multipliers. The pressure marker is arithmetic only, never a relief setting.
Tandem Compound Vertical Engine: Indicated-power Calculator
Compare ideal HP and LP indicated-power contributions from entered mean effective pressures, bores and equivalent piston travel. Shaft power is not predicted.
Smith Rotary Engine: Four-Arm Mechanism, Animation and Indicated Power
See how four slotted arms and an eccentric head disc move in Smith’s rotary engine, with a separate indicated-work, power and torque calculator.
Sellers' Restarting Injector: How It Works, Parts, and Locomotive Feedwater Uses Explained
Explore the fixed tubes and concentric overflow checks in the Sellers restarting injector. Compare throat areas and a selected static delivery-pressure threshold.
Ruth's Rotary Engine: Rotating Cylinders and Eccentric Guide Ring
Explore Ruth's three rotating cylinders and eccentric guide ring, with a calculator for indicated work, mean torque and power.
Rotary Engine (form 5) Mechanism: How It Works, Parts, Formula, and Heritage Steam Uses Explained
Rotary Engine Form 5 explained — how the abutment-and-piston layout converts steam pressure to shaft torque, with worked numbers for heritage mill drives.
Rotary Engine (form 2) Explained: How the Eccentric Vane Steam Mechanism Works, Parts and Uses
How a Form 2 rotary steam engine works — eccentric drum, sliding abutment, multi-vane sealing. Real numbers, worked example, and heritage steam applications.
Rotary Engine (form 1) Mechanism: How a Single-Vane Steam Rotary Works, Parts and Uses Explained
Rotary Engine form 1 explained — how a single-vane steam rotary engine produces torque, where it fits in heritage power plant, and how to size...
Underfeed Mechanical Stoker: Ram Feed Calculator
Explore an underfeed-stoker ram and estimate feed rate, total mass and ram travel from an assumed mass per stroke, cycle rate and elapsed time.
Dake Square Piston Engine: How It Works, Diagram, Parts, and Uses in Steam Hoists and Pumps
See the Dake engine’s nested pistons slide at right angles around a rotating crankpin. Calculate slider stroke, speed, acceleration and ideal pressure-face force.
Columbia Stoker: Pusher Feed Animation and Area Calculator
See the Columbia stoker’s reciprocating pusher, rising coal chute and inclined grates. Calculate an illustrative opening-area allocation and pressure conversion.
American Boiler Stoker Mechanism: How Underfeed Coal Firing Works, Parts, and Diagram
Explore a screw-fed underfeed stoker. Compare entered coal and air rates, air volume at a chosen density and tuyere area without assuming boiler output or...
Jones Mechanical Stoker: Calibrated Screw-Feed Calculator | FIRGELLI
Convert measured mass per screw revolution and rpm into average feed rates. A simplified Jones underfeed arrangement illustrates the feed path; capacity and combustion are...
Feed Worm and Air Blast: Fuel and Air Flow Calculator | FIRGELLI
Compare assumed screw delivery, prescribed primary-air flow and equivalent opening area. Includes mechanism animation and clear limits of the calculation.
Bartrum and Powell Rotary Engine Mechanism: How It Works, Diagram, Parts and Uses Explained
Follow the Bartrum and Powell engine’s orbiting cylinder and rocking wing guide. Compare crank geometry, shaft frequency and an entered clearance.
Toe and Lifter for Puppet Valves: Ideal Area Comparison
Explore a historical toe-and-lifter arrangement and compare ideal valve curtain and seat areas. The tool does not solve valve-train geometry or predict steam flow.
Tappet Lever Valve Motion: Assumed Opening-flank Calculator
Explore an assumed simple-harmonic follower rise, constant lever ratio and entered clearance. Results are ideal travel, not valve timing or flow predictions.
Stevens Boiler Mechanism: How John Stevens' 1804 Porcupine Water-Tube Marine Boiler Works
Stevens Boiler explained — porcupine-tube design, water circulation, steam rate, and real marine examples from the 1804 Stevens Twin-Screw and beyond.
Stephenson Valve Gear Explained: How It Works, Parts, Cutoff Formula and Uses in Steam Locomotives
Stephenson valve gear explained — how the link motion controls steam admission, cutoff, and reverse on locomotives, with worked sizing example and tradeoffs.
Steeple Engine Mechanism Explained: How Twin-Rod Marine Steam Engines Work
Steeple engine explained — vertical inverted steam engine design, dual-rod kinematics, marine and mill applications, sizing formulas, and a worked example.
Steam Pump Mechanism: How Direct-Acting Duplex Pumps Work, Parts, Formula & Uses
How a Steam Pump works, with formulas, a worked example sizing a duplex feedwater pump for a textile mill boiler, and real-world applications.
Spring Balanced Centrifugal Governor: How It Works, Parts, Formula & Uses Explained
Learn how a spring balanced centrifugal governor regulates steam engine speed across load changes, with formula, worked example, and real boiler-room applications.
Rotary Multicylinder Engine: How It Works, Parts, Phasing, Formula and Uses Explained
See how three cylinders rotate with a flywheel around a fixed eccentric crank, and explore a separate calculator for normalized waveform phasing.
Rotary Engine (form 3) Mechanism Explained: How It Works, Parts, Uses & Interactive Calculator
Rotary Engine form 3 explained — how the eccentric piston, abutment, and steam ports convert pressure into continuous shaft torque. Examples, formulas, design notes.
Root's Square Piston Engine Mechanism: How It Works, Parts, Uses & Indicated Power Explained
Root's Square Piston Engine explained — how the unique square-piston steam engine works, real 1890s applications, design math, and a worked sizing example.