VOC aspiration and filtration system with Thermal Oxidizer

VOC dropping generated by a painting machine

• Type of system: VOC aspiration and filtration
• Air flow: 700 m³/h
• Filter type: Pocket prefilter mod. CLEAN, Thermal Oxidizer
• Fan: PRVM 400/2 – 2,2 kW

General description

For the VOC aspiration and filtration deriving from a painting machine, the following system has been realized.

At the beginning, the polluted airflow coming out the painting machine is conveyed to a pocket prefilter which removes possible dust remains or paint deposits deriving from processing.

Then, a thermal oxidizer is used to the high efficiency abatement of volatile organic substances and CO.

A high-performance fan creates the needed depression to ensure the aspiration and bring filtered air out through a stainless-steel discharge chimney.

Project data

The system is used to treat 700 Nm³/h of air polluted by solvents at 30°C. The combustor is equipped with a fan to provide a continuous airflow, while the combustion chamber is made of insulation bricks and ceramic fiber panels. Thermal Oxidizier temperature is 750°C, sized for a permanence time of 1 second, in order to allow the complete oxidation of the volatile organic substances contained. A gas burner, with modulating functioning which is able to work with considerable air surplus as well, is used. 

Operating principle

The airflow is divided into two parts: a part enters inside Thermal Oxidizer directly, while the remaining one goes to the burner which works with fixed air and modulated gas through a fan.
The system provides for the self-recovery of a part of the fumes enthalpy to preheat inlet air from 30°C to 350°C. This is achieved by passing the air through a counter-current heat exchanger with fumes coming out the thermal oxidizer.

The burner is completed with flame detector, ignition system, methane gas / combustion air modulation servo control, combustion air fan with electric motor and relative safety pressure switches.
The control panel on the system contains the main temperature indicators, the temperature adjustment in the combustion chamber in addition to the alarm for the maximum temperature in the combustion chamber, the automatic adjustment of the burner with automatisms and related alarms.