Ace Furnace Consulting Ltd


Ace Furnace

CFD Example 1 Add-On Incinerator Secondary Combustion Furnace

The furnace unit comprises a vertical  cylinder in two parts:


The lower part is a cyclonic mixing section; fumes from the primary incinerator chamber enter the rectangular port. Two tangential oil burners are fitted to the round ports creating powerful mixing and heating of the incoming gases.


Cold air is premixed with the incoming gases on ports in the connecting duct (not shown) to ensure a minimum of 6% residual oxygen in the final mixed gas at the exhaust.


The lower part of the chamber is lined with castable refractory backed by insulation board.


The upper part of the furnace (the residence chamber) is designed as a double skinned metal construction with a stainless steel inner liner and outer case. The intervening space is packed with low thermal mass ceramic fibre insulation.


Not shown in the picture is an upward facing air blown ejector nozzle  to create an upward flow at all times and low pressure at the inlet.


The CFD modelling was intended to test:


1.     That the chosen dimensions would give 2s or more

         residence time at the defined gas flow rates.


2.     That gas mixing would be effective giving an even

         temperature profile.


3.     That the burner output selection was adequate for the

        predicted exhaust flow and temperature from the primary



4.      That gas buoyancy and the action of the ejector would

          maintain a negative pressure with respect to atmosphere

          at the dirty gas inlet.

Furnace Unit