Nordica Stella Instructions For Installation, Use And Maintenance Manual

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Nordica Stella Instructions For Installation, Use And Maintenance Manual Manual pdf 27 page image

STELLA1192000 Rev.03 – EN 276.1. FIRST-AID MEASURESShould any fire arise in the stack or in the flue:a) Close the feeding door and the ash drawer door.b) Close the controls of combustion airc) Extinguish the fire using carbon dioxide fire-fighting means (CO2 dust).d) Seek immediate intervention of FIRE BRIGADE.DO NOT EXTINGUISH FIRE USING WATER JETS.When the fire has been extinguished, let the flue check by an expert to find possible cracks and permeablepoints.7. FLUEEssential requirements for a correct operation of theappliance:• the internal section must be preferably circular;• be thermally insulated and water-proof andproduced with materials suitable to resist to heat,combustion products and possible condensates;• not be throttled and show a vertical arrangementwith deviations not greater than 45°;• if already used, it must be clean;• observe the technical data of the instructionsmanual;Should the flues have a square or rectangular section,internal edges must be rounded with a radius not lowerthan 20 mm. For the rectangular section, the maximumratio between the sides must be ≤ 1.5.A too small section causes a decrease of the draught. It issuggested a minimum height of 4 m.The following features are forbidden and therefore theyendanger the good operation of the appliance: asbestoscement, galvanized steel, rough and porous internalsurfaces. Picture 3 gives some examples of execution.The minimum section must be 4 dm2 (for example 20 x20 cm) for appliances whose duct diameter is lower than 200 mm, or 6.25 dm2 (for example 25 x 25cm) for appliances with diameter greater than 200 mm.The draught created by the flue must be sufficient, but not excessive.A too big flue section can feature a too big volume to be heated and consequently cause difficulties in theoperation of the appliance; to avoid this, tube the flue along its whole height. A too small section causes adecrease of the draught.The flue must be properly spaced from any flammable materials or fuels through a properinsulation or an air cavity.It is forbidden to let plant piping or air feeding channels pass in the same flue. Moreover, it is forbidden tocreate movable or fixed openings on the same for the connection of further other appliances.Picture 3AMax.A+1/2A(3)(1) (2)(4)(1) AISI 316 steel flue with double chamberinsulated with material resistant to 400°C.Efficiency 100% excellent.(2) Refractory flue with insulated doublechamber and external coating inlightweight concrete. Efficiency 100%excellent.(3) Traditional clay flue showing a squaresection with cavities. Efficiency 80%excellent.(4) Avoid flues with rectangular internalsection whose ratio differs from thedrawing.Efficiency 40% poor.A+1/2A