Unigas HTP90A, Manual Of Installation - Use - Maintenance

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14
Pay attention when designing the air duct: dimensioning must be performed according to the flow rate, the temperature, the distance
between the fan and the burner and according to the fan features as well.
Matching the burner to the boiler
The burners described in this manual have been tested with combustion chambers that comply with EN676 regulation and whose
dimensions are described in the diagram . In case the burner must be coupled with boilers with a combustion chamber smaller in dia-
meter or shorter than those described in the diagram, please contact the supplier, to verify that a correct matching is possible, with
respect of the application involved. To correctly match the burner to the boiler verify the type of the blast tube . Verify the necessary
input and the pressure in combustion chamber are included in the burner performance curve; otherwise the choice of the burner must
be revised consulting the burner manufacturer. To choose the blast tube lenght follow the instructions of the boiler manufacturer. In
absence of these consider the following:
z
Cast-iron boilers, three pass flue boilers (with the first pass in the rear part): the blast tube must protrude no more than Dist = 100
mm into the combustion chamber. (please see the picture below)
z
Pressurised boilers with flame reversal: in this case the blast tube must penetrate Dm 50 ÷ 100 mm into combustion chamber in
respect to the tube bundle plate.(please see the picture below)
The length of the blast tubes does not always allow this requirement to be met, and thus it may be necessary to use a suitably-sized
spacer to move the burner backwards or to design a blast tube tha suites the utilisation (please, contact the manifacturer).
ATTENTION! The bellows unit provided is made of canvas and is provided with blocking spacers to avoid breaking it during
installation: first place the bellows unit between flanges, then remove the spacers. Canvas has to be stretched after the instal-
lation, but not stressed.
ATTENTION! Carefully seal the free space between blast tube and the refractory lining with ceramic fibre rope or
other suitable means.
ceramic fibre
refactory wall
Dist
Dm
refactory wall
ceramic fibre