Data entry (Splitter)

pens Data Entry dialogue window to enable data entry for attenuator design. Some of these data items are optional, while others are compulsory. After completing data entry, the calculation process is started by clicking the mouse on "continue...".

The calculation process is performed in accordance with the number of user entries and their mutual influences. When several possible attenuators are found, these are automatically displayed in the Select dialogue window, showing all the appurtenant technical details.

Type

Permissible attenuators with casing:
MSA100; MSA200; XSA100; XSA200; XSA300
Permissible splitters as kit:
MKA100; MKA200; XKA100; XKA200; XKA300

If a splitter type is stipulated, simultaneously specifying the width W, height H, length L and number of splitters, n, these splitters will be displayed as a kit.

Width

Entry optional
in mm.

An entered dimension is interpreted as follows, depending on the other entries:
If type, dimensions W, H, L and the number of splitters, n, are entered, the entered W dimension will apply as a fixed value. (In this case, no entries are required apart from the above-stated values; the programme displays appurtenant technical data). If, on the other hand, the entered information for type, W, H, L and number of splitters, n, is incomplete, the entered width, W, will apply as the maximum permissible dimension.

The following dimensions are valid:
a) Attenuators: W=140...4800 mm. W dimensions over 2400 mm are supplied as split units.
b) Splitter kit:: W=140.. 9999 mm. The W dimension here is the dimension defined by the building!

Height

Height
Entry optional
in mm.

An entered dimension is interpreted as follows, depending on the other entries:
If type, dimensions W, H, L and the number of splitters, n, are entered, the entered H dimension will apply as a fixed value. (In this case, no entries are required apart from the above-stated values; the programme displays appurtenant technical data). If, on the other hand, the entered information for type, W, H, L and number of splitters, n, is incomplete, the entered height, H, will apply as the maximum permissible dimension.

The following dimensions are valid:
a) Attenuators: H=150...3600 mm
b) Splitter kit: H=150...5000 mm. H dimensions over 1800 mm are supplied as split units.
Dimensions in between the dimensions stipulated in the Trox catalogue are supplied at the price for the next largest dimension. Dimensions which differ from those stipulated in the catalogue are marked!

Length

Entry optional
in mm.

An entered dimension is interpreted as follows, depending on the other entries:
If type, dimensions W, H, L and the number of splitters, n, are entered, the entered L dimension will apply as a fixed value. (In this case, no entries are required apart from the above-stated values; the programme displays appurtenant technical data). If, on the other hand, the entered information for type, W, H, L and number of splitters, n, is incomplete, the entered length, L, will apply as the maximum permissible dimension. The following dimensions are valid:
a) Attenuators: L=500...3000 mm. L dimensions over 1500 mm are supplied as split units. b) Splitter kit: L=490...2940 mm. L dimensions over 1470 mm are supplied as split units.

Number of splitters, n

Optional
from 1 to n;

Number of successive splitters in the direction of the W dimension, according to type, gap and width dimension.

Volume flow

Entry optional
from 0 to 500,000 m3/h;

In the simplest case, entry of the volume flow is sufficient for the purpose of designing an attenuator. The programme then assigns a value of 80 Pa for pressure drop and 30 dB for insertion loss, at fm=250 Hz. On the other hand, entry of the volume flow is not necessary when attenuators are fully defined in terms of type, W, H, L and number splitters, n (no flow details will then be displayed, however).

Air velocity

Optional
in m/s;

Values up to a maximum of 20 m/s are accepted.
This limit represents the maximum permissible air velocity in the splitter gap at which no abrasion on the lined splitter surface is to be feared as a result of the air flow. Is very rarely attainable in practice, due to pressure drop and/or flow noise.

Flow noise

Optional
LWA in dB(A);

The entered value is interpreted as the maximum permissible value for the sound power level generated by the attenuator. Values up to a maximum of 65 dB(A) are accepted. Higher values generally mean an inadmissibly high air velocity and pressure drop.
The flow noise is determined in the programme by means of a formula. In cases of doubt, the figures in the Trox catalogue apply.

Pressure drop

Optional
in Pa;

The entered value is interpreted as the maximum permissible value for the flow resistance when a duct is connected at both ends of the attenuator.
One-ended duct connections result in higher pressure drops:
intake without duct connection approx. +10%
discharge without duct connection approx. +30%
The pressure drop is determined in the programme by means of a formula. In cases of doubt, the figures in the Trox catalogue apply.

Attenuation

Optional
in dB per octave;

The insertion loss, De, in accordance with DIN EN ISO 7235 is entered as a minimum value. During the selection process, the programme permits a max. of 1 dB below the specified value. If a greater tolerance is desired, the correspondingly lower value is to be specified.
Insertion losses over 50dB/octave are not attainable for individual attenuators.

Variants

2 designs of connection flange are possible for attenuator casings:
-P galvanised air duct profile, 30mm high (4-hole attachment), standard
-W galvanised angle frame, 35x3mm(drilled, spacing approx. 150mm)

2 variants are possible for splitter surfaces:
-F Glass fibre fabric lining (standard)
-L perforated metal cover on glass fibre fabric