Abatement with afterburner of VOCs generated by a painting machine.
- Plant type: VOC extraction and filtration
- Air flow rate: 700 mc/h
- Filter type: Pocket prefilter mod. CLEAN, Afterburner
- Fan: PRVM 400/2 - 2.2 kW
General description
For the extraction and filtration of VOCs from a painting machine, a system complete with a pocket filter and afterburner was built.
The polluted air flow from the exit of the coating machine is initially conveyed to a pocket prefilter that removes any dusty residues or paint sludge from the process. A high-efficiency afterburner (CTR) is then used to abate volatile organic compounds and VOCs. A high-efficiency fan creates the necessary vacuum to suck in and convey the filtered aeriform to the outside through an exhaust stack made of stainless steel.
Afterburner design data
| Air flow rate | 700 Nm3/h |
| Flue gas inlet temperature to be treated | 20-30°C |
| VOC content | 5,000 mg/Nm3 |
| Available fuel | Network methane |
The plant is designed to treat 700 Nm3/h of solvent-polluted air at a temperature of 30°C.
A blower sucks in and provides a constant flow rate of process air, while the combustion chamber thermally insulated by an insulating brick and ceramic fiber panel cladding allows high temperatures to be reached.
To ensure complete oxidation and elimination of pollutants, the design values of the afterburner establish a combustion temperature of 750° for a residence time of 1 second.
A modulating gas burner is also provided that is capable of working even with considerable excess air. Finally, some of the process air is used as construction air.
Principle of operation of the afterburner
The air flow is divided into two parts: one part enters the afterburner directly, while the remainder is conveyed via a fan through the burner, which therefore operates with fixed air and modulated gas. The system involves self-recovery of part of the flue gas enthalpy to preheat the incoming air from a temperature of 30°C to a temperature of 350°C. This is done by passing the air through a heat exchanger in countercurrent with the flue gas leaving the afterburner.
The burner is complete with flame detector, ignition system, methane gas/combustion air modulation servocontrol, combustion air fan complete with electric motor and related safety pressure switches. The control panel located on board the system contains the main temperature indicators, temperature regulation in the combustion chamber in addition to the alarm for the maximum temperature in the combustion chamber, automatic burner regulation with automatisms and related alarms.
