Controls, dosing & monitoring
A scrubber only removes what its chemistry allows on the day. Liquor that has been spent, a blocked spray nozzle or a pump that has tripped will all leave a system that looks like it is running and is not treating anything. Instrumentation is how you know the difference.
The principle
We build the control system for every scrubber we supply, and we retrofit controls to plant we did not build where the mechanical side is sound but the instrumentation has been outgrown.
The principle is that the extract fan and the scrubber are one machine. If the scrubber cannot treat, the process should know — and on the duties where that matters, it should stop.
Closed-loop chemistry
pH and ORP measured continuously, reagent dosed to setpoint, conductivity used to bleed and refresh the liquor before removal falls off.
Fan interlock and trips
Liquor flow proving, low sump level and dosing failure raise an alarm and, where the duty demands it, inhibit the extract fan.
Differential pressure trending
Pressure drop across the packing is the earliest sign of fouling. Trending it turns an unplanned shutdown into a planned clean.
Open interfaces
Volt-free contacts for the essentials and Modbus RTU or TCP for everything else. No proprietary gateway, no licence to read your own data.
Design envelope
Indicative ranges for this system type. Your figures are calculated against your duty and issued on a datasheet before anything is built.
| Panel build | Form 2 as standard, IP54 indoor or IP65 external, to BS EN 61439 |
|---|---|
| Control | Relay logic on simple duties; PLC with HMI where staging or trending is needed |
| Measured | pH, ORP, conductivity, sump level, liquor flow, differential pressure, fan status |
| Dosing | Peristaltic or diaphragm metering pumps, bunded reagent storage, low-level alarm |
| Alarms | Volt-free common and individual contacts; local beacon and sounder to order |
| Integration | Modbus RTU or TCP; BACnet/IP where the BMS requires it |
| Hazardous areas | ATEX-rated instruments and zoned enclosures where DSEAR requires |
What it is built to
Equipment is one part of a duty holder's obligations. These are the standards and regulations we design this system type against — your own risk assessment and permit conditions still govern.
- Panels built and tested to BS EN 61439-1/-2
- Machinery safety assessed to BS EN ISO 12100; functional safety where a trip is safety-related
- ATEX 2014/34/EU equipment selection where DSEAR identifies a hazardous area
- UKCA marked, with schematics, I/O schedule and test certificate supplied
Other systems
Compact fume cupboard scrubbers
Packed-bed scrubbers sized for one to four fume cupboards, built to fit the plant room you already have.
SpecificationsPacked tower scrubbers
The workhorse for soluble gases — counter-current or cross-flow, from a few hundred to tens of thousands of cubic metres an hour.
SpecificationsOdour control scrubbers
Chemical scrubbing for hydrogen sulphide, mercaptans, ammonia and the amine odours that generate complaints.
SpecificationsTell us the duty and we will size it
Send the gas composition, the flow and the discharge condition you have to meet. We will come back with what will work and what it will take out — and say so plainly if this is the wrong system for the job.