Depending on the temperature of a gas stream and the fabric selected for purification, it may be necessary to cool these gases before entering the bag filter.
Water cooling
This is carried out in a tower or “quencher”, and was the most characteristic system until a few years ago in large rotary kilns for cement, lime and dolomites, for example. They acted to cool the gas before the main electrofilter. Subsequently, bag filters came to replace electrofilters in most of the new premises, or took their place in remodelling, renovation or retrofitting operations, of which GORCO has ample experience.
Calculation
Calculating the water necessary for cooling a mass of hot gas from the kiln outlet before possibly entering the bag filter (about 220-240º maximum with fibreglass bags and Teflon membrane) is relatively simple with an enthalpy, gas/water balance; by considering that the water goes from the liquid to the gaseous phase with the consequent available enthalpy of vaporisation at 100ºC.
The most important factors to take into account are the speed regime, (quencher diameter) and mixing time before the formation of sludge, which determines the minimum height of the tower.
Sprayers or Nozzles
To ensure effective mixing, the design and arrangement of the nozzles that introduce the finely sprayed water into the gas stream is critical. GORCO collaborates in this section with first brand manufacturers.
There is a highly extensive range of models for water injectors, sprayers and nozzles for each application. Without elaborating too much, a simple subdivision of them into two large groups can be made:
- water spray injection.
- water/air mixture injection.
GORCO supply
The equipment offered by GORCO can cover the TOWER itself with its INJECTORS and components in the field; or the entire WATER AND AIR SUPPLY circuit, including motor pumps, pipes, valves and complete regulation and control systems.
