Large quantities of moist and humid air and steam evaporate from paper production machine into the machine hall during paper manufacturing, from the wire section, the press section and the dryer section. The vapour and steam is corrosive and destructive to all the surfaces in the machine hall onto which it condensates, including concrete constructions, steel reinforcements, factory plant and the paper machine itself.

paper factory production machine extraction hood for corrosive steam and air
GUPEX® HDS paper machine steam extraction hood system

As part of the paper production process the moist humid air from the pulp and paper must be removed by evaporation and air extraction from the wire section, press section and dryer section of the paper machine before it flows into the machine hall and causes damage to plant, buildings and the working environment.

This vapor and steam are corrosive and therefore over time destructive to all surfaces onto which it condensates, including concrete constructions, steel reinforcements and plant and all machinery surfaces.

With the life expectancy of buildings and machinery in paper production factories significantly reduced through corrosion, they must constantly be repaired or replaced.  Over time this corrosion breakdown adds significantly to the operating cost of  the factory and reduces the overall competitiveness of the owner.

The humidity and temperature in the space surrounding the paper production machine is very high.  The steam vapour in the machine hall creates an uncomfortable and unhealthy working environment, and this reduces the productivity which further adds to the paper production cost.    

During the paper–making process large amounts of excess moist and corrosive vapour must be extracted and ventilated away as part of the paper production machine process.  This is all too often simply done through very big fan units in the factory ceiling.  However that means all the corrosive vapour flows through the whole machine factory hall, getting into contact with all surfaces and condensing and turning into a corrosive acid which attacks and destroys all surfaces and machinery.

When this large volume of steam and air is extracted from the paper factory, it must be replaced by the same volume of fresh, outside, cold air.  The paper production process needs the air to be very hot for it to absorb the maximum amount of water before transporting it away from the production line.  The conventional method is to pre–heat the ouside, cold air through a steam heater battery or other heating source, using increasingly expensive energy.

Air extraction hood over wire section of paper machine
Retractable hood over wire section of paper machine

The GUPEX® HDS paper machine steam extraction hood is a tried and tested system for effective steam air ventilation and air flow control for paper production factory machines.  The steam and hot moist air capture and extraction hood can be supplied as an integrated system for optimal air extraction, taking into account the amount of water to be removed from the paper production machine.  Corrosion resistant and thermally insulated ductwork is almost always part of the GUPEX supply.


The extracted steam air is hot and contains large quantities of energy which normally is just wasted.  Energy prices are rising at a very high rate and energy efficiency schemes which were uneconomical only a few years ago are now becoming extremely attractive in terms of financial savings.

To recover the optimum amounts of energy from the extracted steam air, the GUPEX® air to air (gas to gas) plate heat exchanger can be built into the system, positioned to pre–heat the incoming air which goes into the paper production machine as part of the continuous air cycle.  This air to air plate heat exchanger is made of glass fibre reinforced polyester (GRP) which is corrosion resistant to operate successfully with long operating life even in hostile, corrosive and dusty paper factory ventilation environment.

This simple, yet highly effective and corrosion resistant and maintenance free system ensures that both the corrosive steam and the energy from the paper production line only goes where it is designed to go. 


Another important factor is that with GUPEX® HDS paper machine steam extraction hood system the corrosion problems to buildings and machinery are reduced or eliminated completely.  The improved air environment will add decades of years to machinery and building walls and roof, which in the long run represents one of the larger financial savings possible in paper manufacture.


The GUPEX® HDS paper machine steam extraction hood system is made of a material with non–condensing surface thereby prevents the dripping of condensed water onto the production line.  This improves the quality of the finished paper and therefore reduces production cost.


With the removal of the humid, moist, hot and acidic air, steam and vapor from the space around the paper production machine and the factory in general made possible by the GUPEX® HDS paper machine steam extraction hood system, the working environment is improved dramatically.  Health and Safety issues are increasingly important to the well–being of everyone involved.  The employees are an organisation's greates asset. Therefore to look after the workforce is both worthwhile and a cost effective endevour.


  • Effective removal of all moisture from the paper process?                Yes

  • Wasted energy from extracted steam and air?                        Yes, Recovered

  • Condensed acidic water dripping onto production line?            Yes, Eliminated

  • Unhealthy working air environment?                                         Yes, Improved

  • Corrosive damage to buildings and machinery surfaces              Yes, Solved