Round mufflers for fans and ducting systems

Round mufflers are usually situated behind a fan in the exhaust ducting.  They lower the noise from the fan in the pipeline from the exhaust ducting to the environment.

Round mufflers in the GIDLY catalog

Round mufflers are always sorted by their diameter and their pressure resistance Group I, Group II. Individual models sorted by their dimensions are displayed here.

For more slide valve variants go to the CATALOG – Round ducting Group II and Group III 

∅ 80                 SK I folded                    SK II welded
∅ 100               SK I folded                    SK II welded
∅ 125               SK I folded                    SK II welded
∅ 150               SK I folded                    SK II welded
∅ 180               SK I folded                    SK II welded
∅ 200               SK I folded                    SK II welded
∅ 225               SK I folded                    SK II welded
∅ 250               SK I folded                    SK II welded
∅ 280               SK I folded                    SK II welded
∅ 300               SK I folded                    SK II welded
∅ 315               SK I folded                    SK II welded
∅ 330               SK I folded                    SK II welded
∅ 355               SK I folded                    SK II welded
∅ 380               SK I folded                    SK II welded
∅ 400               SK I folded                    SK II welded
∅ 450               SK I folded                    SK II welded
∅ 500               SK I folded                    SK II welded
∅ 560               SK I folded                    SK II welded
∅ 600               SK I folded                    SK II welded
∅ 630               SK I folded                    SK II welded
∅ 650               SK I folded                    SK II welded
∅ 710               SK I folded                    SK II welded
∅ 800               SK I folded                   SK II welded
∅ 900               SK I folded                    SK II welded
∅ 1000             SK I folded                    SK II welded

To download DWG drawings, STEP models or 3D-PDF presentation please proceed through the CATALOG – Round ducts Group II and Group III 

Mufflers usage

Mufflers lower the noise pollution of an industrial dedusting system, because the main noise source in the system is the high-pressure fan. A noise level higher than 110 dB(A) is often measured at the high-pressure fan exhaust, therefore mufflers are usually situated in the ducting behind the fan. An important factor for proper attenuation of the noise in the muffler is the air flow speed which should be in the range of 8 to 10 m/s. When the right conditions are met, a muffler of a 1 meter lenght can attenuate up to 15 dB(A).

The round mufflers are not subject to wear, because they are usually situated behind the filter unit. Mufflers are supplied in Group I galvanized design, Group III EN11 welded design and Group III stainless steel. The muffler selection is based on the exhaust duct design and the environment in which the muffler will be located. Please note that when situated behind a flue gas extraction and filtration system, mainly from gas melting furnaces, a condensation occurs in the muffler and the steel absorbers can be quickly damaged by corrosion – a stainless steel finish is appropriate here.

Muffler construction

The main part of the muffler is the inner lining made from a sound-absorbing material. The lining is situated betweet an inner perforated steel part and the outer shell.  Mufflers in Group III are made disassemblable with the possibility of replacing the inner lining in case of cloggage or other degradation. Group I mufflers must not be used as a support part of the exhaust pipe and they must be supported separately. Mufflers of Group III can be used as a ducting support part.

EXAMPLE OF USING A ROUND MUFFLER IN INDUSTRIAL AIR EXTRACTION
MUFFLER TYPE EXAMPLE OF USE
Galvanized muffler Group I Welding shops, hoppers, grinding shops
Welded muffler Group III EN11 Foundries, metallurgy, quarries
Welded muffler Group III EN17 Melting furnaces

Offered variants of round mufflers

Dimension variants

Inlet dimensions DN 80 to DN 1250
Material width Group I – 1mm galvanized
Group III – 1,5- 2,0 mm welded

Material design
EN 11 – Sheet metal 11375 with selectable surface finish
EN 17 – Stainless steel 1.4301 for use in food industry
EN 17 – Stainless steel 1.4404 with increased chemical resistance
EN 17 – Stainless steel with increased chemical and thermal resistance

Surface finish for  EN 11 – 11375
Galvanized
Powder coated RAL1015 (ivory)
Powder coated RAL5010 (blue)
Powder coated RAL9001 (cream white)
Powder coated RAL9005 (black)
Powder coated RAL9006 (silver – aluminium))