Exhaust Extraction For Several Machines - GIRBAU ED460 Installation Instructions Manual

5.5.2. Exhaust extraction for several machines

The best extraction is achieved by connecting the extraction ducts individually for each machine. However,
when several machines need to be connected to a main manifold, bear in mind that its dimensions should be as
indicated below (Fig. 5.12).
 The diameter of the main duct should increase progressively as individual ducts are added (Fig.
5.12/A). The minimum diameters should increase proportionally if the approximate length of the
collector (Fig. 5.12/B) exceeds 6 metres (20 ft) or has several elbow joints.
 The cross-section can be circular or square, provided that the area is not reduced.
 The assembly and layout of the ducts should ensure that the internal surfaces are uniformly smooth, in
order to prevent lint from accumulating at the joints and be easy to clean.
 The extraction ducts from each of dryers to the manifold (Fig. 5.12/A) should:
 be fitted with a backflow valve.
 have an input angle of 45º in the direction of flow (Fig. 5.12/C).
 have rounded elbow-joints (Fig. 5.12/C).
 be connected to the bottom or to one side of the main duct (Fig. 5.12/C).
 be made of sheet metal or other non-combustible material.
 Incorrect dimensions or poor fitting of any of the sections of the ducts may cause excessive
backpressures, which can cause build up of fluff, slow drying and an increased risk of fire.
 Where the extraction duct passes through a wall or a ceiling made of combustible material, the opening
to be made should be at least 5 cm (2 in) greater than the diameter of the duct, and the latter should be
centred in the opening (Fig. 5.12/D).
 The main manifold should have an access point for inspection and maintenance at the end (Fig.
5.12/E).
A
B
C
D
E
F
Connecting the machine
Description
Individual dryers
Length of the manifold to the dryers
Input angle of 45º in the direction of flow
Opening 5 cm (2 in) greater than the diameter of the
manifold
A cleaning and inspection cover
Air output
62
Fig. 5.12
Code No. 549758
Rev. nº 10/0418