Infrared radiator that is designed as surface radiator

An infrared irradiating heater for drying paper and cardboard webs, said heater comprising:

• a housing;
• a radiating body in said housing comprised of a ceramic and having a planar radiating surface, a multiplicity of substantially flame-free passages extending perpendicular to said surface and opening at said surface, and a rear surface, said passages extending to said rear surface, said passages having lengths less than 300 mm, the total cross sectional area of said passages at said planar radiating surface being in a ratio to the area thereof in excess of 50%, and said passages having length to maximum diameter ratios of at least 5;
• a burner plate in said housing spaced from said rear surface and defining a combustion chamber therewith, said burner plate being provided with throughgoing bores opening into said combustion chamber;
• a peripherally continuous seal extending around perimeters of said burner plate and said radiating body and sealing said combustion chamber so that combustion in said heater is substantially confined to said combustion chamber;
• a distribution chamber formed in said housing along a side of said burner plate opposite said combustion chamber for distributing a fuel/air mixture to said bores;
• and
• a mixing pipe supplied with fuel and air opening into said distribution chamber.