Despite the fact that they have been designed to be as simple and affordable to build, the De Montfort incinerators must be built in an appropriate location with care and using the right materials. See the "Guidelines on how to construct, use and maintain a waste disposal unit" (English and French versions available below).
Choosing an appropriate location:
The incinerator should be built at a convenient distance away from buildings so that any smoke or flue gas does not enter buildings. 150 metres is the suggested minimum, unless the buildings are very high in which case the distance may need to be increased. The incinerator should be built on a solid concrete foundation appropriate to the local ground conditions. It should be convenient for the waste disposal officer to carry the waste containers to the site, and facilities to store the waste securely before burning should be provided. An ash pit to finally dispose of ashes should be provided nearby.
Choosing a qualified builder:
It is best to choose a contractor who is competent in simple bricklaying and also in fabricating mild steel sections so that one person can be responsible for the construction of the whole incinerator. The contractor should understand the importance of the correct choice of refractory materials and ideally should be able to source all the materials.
Selecting the right materials:
The incinerator will be operated at temperatures which can occasionally exceed 1000°C. Thus it is important that refractory bricks and mortar are used throughout. The mild steel specified is either in the form of sheet steel or rolled steel angle, or rolled steel “U” section (channel). It is often not possible to obtain this U section steel, but it can be substituted by two lengths of rolled steel angle welded to form the correct shape. exact cross-sectional dimensions are not critical. The thickness of the mild steel plate is important to avoid premature failure due to corrosion. The chimney should be made from steel pipe 3mm thick if it can be obtained, and its diameter can vary between 100mm and 150mm to ease procurement. If no such pipe can be obtained it should be fabricated from the thickest plate that can be rolled with the tools available. The thinner the chimney gauge, the more frequently the chimney will need replacing due to corrosion.
However obvious, it is always usefull to repeat that both the quality of combustion as well as the lifespan of the incinerator depend to a high degree on the use of appropriate materials and proper building techniques.