Steady-state simulation
A steady-state process simulator that closes the balance on your drawing
Recycle loops converge automatically, sensitivity studies take one click, and the stream table comes straight off the canvas. Built for feasibility work, not for replacing Aspen.
- Steady-state solver with automatic recycle convergence
- Sensitivity analysis across any parameter
- Custom unit equations in plain math, no compilation
No Fortran, no vendor plugins. Windows and Linux, offline licence available.
Recycle loops without the manual trial and error
Hand-calculating a loop means guessing a tear stream, iterating, checking, and doing it again — often a dozen times. The built-in solver does that iteration for you and reports when the balance closes within tolerance.
With several interacting recycles and subsystems, the difference compounds: change one conversion and the whole flowsheet recalculates.
Model the units the standard library forgot
Water treatment, metallurgy, solid waste and fine chemicals are full of non-standard units. Instead of writing compiled subroutines, attach a plain mathematical expression to a node to describe conversion, split ratio or removal efficiency.
Standard unit operations — reactors, distillation, heat exchange, mixers, splitters, pumps — are available out of the box, and custom ones sit on the same sheet.
- Custom parameter groups and tag-based libraries
- Sensitivity studies on any input variable
- Read data from Excel or a database connection
Where it fits
IAutoDrawSim is aimed at conceptual design, feasibility studies, debottlenecking and plant benchmarking, where a fast closed balance matters more than a rigorous thermodynamic model. For acceptance-grade calculations with full property packages, keep Aspen Plus or HYSYS.
For everything upstream of that — the flowsheet sketch, the first balance, the option comparison — it removes the spreadsheet in the middle.
Compared with common approaches
| Excel trial and error | Aspen / HYSYS | IAutoDrawSim | |
|---|---|---|---|
| Drawing and calculation in one place | No | Partly | Yes |
| Automatic recycle convergence | Manual | Yes | Yes |
| Custom non-standard units | Scattered formulas | Compiled subroutines | Plain equations |
| Learning curve | Low | Steep | Low |
| Licence cost | Low | High | Low |
Frequently asked questions
How is this different from Aspen Plus or HYSYS?
Scope and rigour. Aspen and HYSYS are built for rigorous thermodynamics, property packages and phase equilibria. IAutoDrawSim targets conceptual and feasibility work where speed and a closed balance matter more than property accuracy.
Does it do dynamic simulation?
No. It focuses on steady state, recycle convergence and sensitivity analysis. Dynamic control studies are outside its scope.
Do I need to write code for custom units?
No. Custom units are described with ordinary mathematical expressions — no compiler, no SDK.
Can I export the results?
Stream tables, mass balances and consumption figures export to Excel and PDF.