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Aeration Blower Set (Engineered Unit)
A blower house delivering air to an aeration lane — the first engineered unit whose process medium is air rather than water.
Which simulation? Running this unit uses the client-side, PLC-style scan simulation in your browser, not the server-side biokinetic process simulation. The blower set's own dissolved-oxygen figure is part of its scan model, and is not an ASM biokinetic result. See Which "simulation" this section is about.
| Slug | aeration-blower-set |
| Name in the library | Aeration Blower Set (Engineered Unit) |
| Category | Process Units/engineered |
| Seeded | version 0.1.0, maturity published |
| Interface points | 5 — air_out, air_demand, pressure_sp, power, signals |
| Asked on drop | 10 for a new set, 14 for an existing one |
| Editable setpoints | 12 |
| Fault catalogue | 22 cases, filtered to what is fitted |
| Control loops | 8 generated graphs |
What it models
Two to four blowers — positive displacement, rotary screw, multistage or turbo — of which up to two may be standby, on a common air header to fine-bubble diffusers at a stated submergence.
The drawing it generates carries one train per machine (inlet filter, blower, variable-speed drive, discharge pressure and temperature transmitters), the common header with its pressure, flow and temperature transmitters, the hardwired high-high pressure switch and the mechanical relief, the blow-off valve to atmosphere, the motorised header valve at the lane boundary, the control panel, and the off-page connections.
The plant model integrated during a run is the air side: the header pressurising and depressurising against what the running machines deliver and what the diffusers take, the pressure budget through the header, machine discharge temperature, the blow-off and relief paths, and the energy and vented-air accumulators.
What it derives rather than asks
The air demand is derived, and cannot be overridden. The minimum, average and peak demand come from the load the lane receives — the population equivalent, the BOD load, the aerobic volume and the diffuser submergence — and there is no parameter that sets them directly.
What the three demand parameters on this template do carry is the figure declared at the air_demand port: zero means "use this set's own derivation", and any value above zero is what a neighbouring lane states it needs. That declared figure is published and compared with what the set delivers — but it does not re-size the set. Demand propagation into the sizing is not built. The parameters are therefore never asked on drop, because asking for a number the resolver would then ignore would misrepresent what the template does with it. What is asked is the load basis the demand is derived from.
Key parameters
Asked on drop
| Parameter | Unit | Type | Asked |
|---|---|---|---|
| Design basis | — | new / existing | always |
| Population equivalent | — | number | always |
| BOD₅ load | kg/d | number | always |
| Aerobic volume | m³ | number | always |
| Diffuser submergence | m | number | always |
| Blower type | — | positive displacement / rotary screw / multistage / turbo | always |
| Blowers installed | count | 2–4 | always |
| Standby blowers | count | 0–2 | always |
| Control variable | — | header pressure / total air flow | always |
| Rated capacity of one machine | Nm³/h | number | always |
| Header internal diameter | mm | number | if existing |
| Header length | m | number | if existing |
| Header sum of K | — | number | if existing |
| Blow-off valve capacity | Nm³/h | number | if existing |
The template carries 50 parameters in total.
Editable setpoints
| Setpoint | Unit |
|---|---|
| Header pressure setpoint | mbar |
| Pressure loop gain | % per mbar |
| Pressure loop integral time · Pressure loop derivative time · Setpoint trim step interval · Fail-to-start time · Auto reset after | s |
| Speed reference maximum · Most-open-valve target opening | % |
| Blow-off open below flow · Blow-off close above flow | Nm³/h |
| Dissolved oxygen setpoint | mg/l |
Everything else the generated program reads — the staging thresholds and delays, the minimum run, the starts limit, the high-high pressure switch, the relief, the trips, the filter differential pressure, the minimum flow, the standby start time and the energy target — is a rule-set value or a derivation, not a setpoint.
Control loops
Eight generated graphs:
Header pressure control · Pressure setpoint trim · Staging · Each blower (one per machine) · Blower protection and minimum flow · Hardwired over-pressure and over-temperature · the outstation
What the outputs mean
Published port values
| Port | What it publishes |
|---|---|
air_out | The air the set delivers — normal volume flow, header gauge pressure and discharge temperature |
air_demand | The demand figure in force, with the pressure it is required at — this set's own derivation, or a neighbour's declaration |
pressure_sp | The header pressure setpoint the trim loop is working to |
power | kW, kVA and amps, with the essential load and the largest single start |
signals | The size of its signal set |
For the reference configuration air_out reads 2000.0 Nm³/h at 0.604046 bar g and 81.5291 °C; air_demand 1753.5361 Nm³/h at 0.529046 bar g; power 43.2348 kW / 50.8645 kVA / 73.4166 A with an essential load of 43.2348 kW and a largest start of 29.0068 kVA; and the signal set 21 DI / 8 DO / 15 AI / 3 AO plus 2 communications registers.
Overview figures
Number and type of machines, duty/standby split, duty capacity with the standby out, air demand (minimum / average / peak), header setpoint against the machines' rating, maximum demand in kW, specific energy, design findings, control loops.
Live facts during a run
Titled Blower set: the clock, the header pressure with the transmitter's reading, the setpoint in force, demand against delivered, the speed reference, each machine's state, blow-off and relief activity, the dissolved oxygen figure, the air vented, and energy consumed.
Trend panels
Four: header pressure (with the PT reading dashed, and reference lines at the relief, the high-high pressure switch and the setpoint's min / working / max), demand against delivered, speed reference, and blowers running.
The calculation charts
Two:
- the system curve — static plus the header's velocity-squared term, with
kfitted at the average flow, drawn against the rating point the machines were selected for, and the three design demands (minimum, average, peak) marked on it; - the blower envelope — one band per number of machines running, from the turndown coverage the selection publishes. This is what turns "the set can deliver every flow between its minimum and its maximum" from a claim into a picture.
Faults you can inject
| Group | Cases |
|---|---|
| Machines | one duty blower trips · both duty blowers trip · every blower stopped · a blower fails to start · the starts-per-hour limit reached |
| Header pressure transmitter | signal lost · frozen · drifts +100 mbar |
| Header flow transmitter | signal lost |
| Blow-off | stuck open · stuck closed |
| Inlet filters | at the alarm differential pressure · collapsed |
| Hardwired | the high-high pressure switch will not operate · stuck operated |
| Pipework | a header isolating valve shut |
| Supply | 2 h supply failure |
| The ports | the lane steps the demand to the duty set · past the installed set · the pressure setpoint port goes dead |
| Setpoints | the stage-down threshold set to 55 % |
| Per-machine temperature transmitter | a blower's discharge TT drifts high |
Honest limits
- Seeded at
publishedmaturity: its configuration matrix passed, so it is visible to every user who passes the plan, tenant and allocation gates. - The declared demand does not re-size the set (see above). It is published and compared, nothing more.
- The dissolved-oxygen figure here belongs to this unit's scan model. It is not an ASM biokinetic result and should not be read as one.
- The run verdict and the design findings are shown on the workspace's Validation view.
- Nobody has recorded watching this unit run in a browser.