Compact fume cupboard scrubbers
Laboratory extract is a hard duty in a small space. The flows are modest, the gases are aggressive and variable, and there is rarely a spare plant room. Our compact scrubbers are designed around that constraint — a full counter-current packed bed, recirculation tank, dosing and controls, on a footprint that fits through a doorway.
- HCl
- HF
- HNO₃
- H₂SO₄ mist
- NH₃
- Amines
- Cl₂
- SO₂
The principle
A fume cupboard is a capture device. It keeps the operator safe, but everything it captures is still in the ductwork, and under COSHH and your discharge conditions it cannot simply go up a stack untreated. A scrubber is what closes that gap.
These units are self-contained: tower, sump, circulation pump, spray header, mist eliminator, instrumentation and control panel arrive as one assembly, wet-tested before it leaves us. On site it needs a duct connection, a drain, a water feed and a supply.
Built for a small plant room
From roughly a 700 × 700 mm footprint. Skid-mounted, lifting points fitted, and split into sections where access demands it.
A real packed bed, not a spray box
Random polypropylene packing gives the surface area a soluble gas needs. Bed depth is set by the removal you have to achieve, not by the size of the cabinet.
Dosing that holds the chemistry
pH is measured continuously and reagent dosed to hold the setpoint, so removal does not quietly fall away as the liquor is spent.
Interlocked with the extract
The fan and the scrubber are interlocked. If liquor flow is lost, you know about it — at the panel, at the BMS and, where you want it, at the cupboard.
Design envelope
Indicative ranges for this system type. Your figures are calculated against your duty and issued on a datasheet before anything is built.
| Duty range | 200 – 3,000 m³/h (typically one to four cupboards) |
|---|---|
| Configuration | Vertical counter-current packed tower, integral sump |
| Body materials | Polypropylene as standard; PVDF or GRP where the duty needs it |
| Packing | Random polypropylene, 25–50 mm, depth set by duty |
| Scrubbing liquor | Water, dilute sodium hydroxide, or dilute acid for alkaline gases |
| Removal efficiency | 95%+ single stage on soluble acid gases; 99%+ two-stage |
| Pressure drop | Typically 300 – 800 Pa across the wetted bed |
| Mist elimination | Chevron or mesh pad, removable for cleaning |
| Instrumentation | pH, sump level, liquor flow proving, differential pressure |
| Interfaces | Volt-free alarm contacts and Modbus RTU/TCP to BMS |
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.
- Sized to work with fume cupboards tested to BS EN 14175
- Supports the employer’s duties under COSHH Regulations 7 and 9
- Designed for thorough examination and test at intervals of no more than 14 months
- UKCA marked; supplied with an O&M manual and commissioning record
Other systems
Packed 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.
SpecificationsVenturi scrubbers
High-energy scrubbing for particulate, fume and sub-micron mists that a packed bed will not hold.
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.