Rectangular straight silencer

Transcription

1 silencer DLD Dimensions b a l Description DLD has a conventional design with dimensions that not exceed the corresponding connection dimensions. The silencer can be manufactured in all standard duct sizes. For low-built solutions, see LRLB page. Design DLD has an outer sheet casing of trapezoidal corrugated sheet metal for stability and reduced risk of natural oscillation. DLD is designed for low air resistance with baffle combinations that attenuate particularly low-frequency well. The type of insulation material has been developed to provide good properties, low weight and to be cleanable. DLD meets the requirements of air tightness class C. Tools for dimensioning and planning The software CADvent and DIMsilencer offer features for dimensioning and selection of products in an environment with D modelling. Computerised planning can be conducted with automatic presentation of levels, pressure drop etc. Published data as per ISO. Ordering example DLD TRA Product Width height a b Length l Accessories If alternative material is required, this shall be stated when ordering, e.g. aluminium zinc (AZ) and stainless acid-proof steel. The silencer is also available with the following accessories/ options. TRA TRB TRC TP AIA AIB = Non-insulated inspection hatch. = Hatch intended for external insulation.* = Hatch intended for external insulation.* = Absorbent lined with perforated sheet. = 0 fire protection insulation. Note! a and b dimensions increase by 00. = 00 fire protection insulation. Note! a and b dimensions increase by 00. The dimension of the hatches is adapted for cleaning and inspection of all baffle spacings. Manual dimensioning see pages. Insertion attenuation see pages. * Specify insulation thickness when ordering. 0 We reserve the right to make changes without prior notice

2 silencer DLDR Dimensioner a l b 0 Description DLDR has a conventional design with dimensions that not exceed the corresponding connection dimensions. The silencer can be manufactured in all standard duct sizes. The silencer is provided with cleaning hatch and removable baffles. Design DLDR has an outer sheet casing of trapezoidal corrugated sheet metal for stability and reduced risk of natural oscillation. DLDR is designed for low air resistance with baffle combinations that attenuate particularly low-frequency well. The type of insulation material has been developed to provide good properties, low weight and to be cleanable. DLDR meets the requirements of air tightness class C. Tools for dimensioning and planning The software CADvent and DIMsilencer offer features for dimensioning and selection of products in an environment with D modelling. Computerised planning can be conducted with automatic presentation of levels, pressure drop etc. Published data as per ISO. Ordering example DLDR TRB Product Width height a b Length l Alternative for placing of hatch (Alt on top, alt on side, alt on bottom.) Accessories If alternative material is required, this shall be stated when ordering, e.g. aluminium zinc (AZ) and stainless acid-proof steel. The silencer is also available with the following accessories/ options. TRB TRC TP AIA AIB = Hatch intended for external insulation.* = Hatch intended for external insulation.* = Absorbent lined with perforated sheet. = 0 fire protection insulation. Note! a and b dimensions increase by 00. = 00 fire protection insulation. Note! a and b dimensions increase by 00. The dimension of the hatches is adapted for cleaning and inspection of all baffle spacings. Manual dimensioning see pages. Insertion attenuation see pages. * Specify insulation thickness when ordering. We reserve the right to make changes without prior notice

3 Manual designing for DLD and DLDR A of can be designed manually, for more combinations of and faster calcu-lations use DIMsilencer. Manual method of calculation is shown below: A Specify connection dimensions and flow-type location of the silencer. Width 00 Heigh 000 Length 0 Location Exhaust air DLD B Specify the sound power level before the silencer. Read the insertion attenuation from the tables on pages. Calculate the sound power level after the silencer irrespective of the air flow (selv ). Insertion attenuation Sound power level before silencer Attenuation from table pages Sound power level after silencer without self Hz Hz 0Hz 00Hz 000Hz 000Hz 000Hz 000Hz Resistance inlet,, 0 C Determine the pressure drop with help of the graph on page and table on page 0. In this case we have straight ducts before and after the silencer. Pressure drop Graph on page, use resistance, area and air velocity Correction at disturbance according table on page 0 Area 0, m² Air flow 00 l/s Air velocity m/s Pressure drop Pa Factor Pressure drop after correction Pa D Determine the self from the silencer at present air flow. Calculate the sound power level after the silencer inclusive the self. Hz Hz 0Hz 00Hz 000Hz 000Hz 000Hz 000Hz Graph on page, use resistance and air velocity Correction for gross cross section area Sound power level after the silencer (Logarithmical addition of self and sound power level after the silencer without self ) 0 We reserve the right to make changes without prior notice

4 The following table can be used for own manual calculations in accordance with the example on the previous page. Designing table for DLD and DLDR With Height Length Location Insertion attenuation Hz Hz 0Hz 00Hz 000Hz 000Hz 000Hz 000Hz Resistance inlet Sound power level before silencer Attenuation from table pages Sound power level after silencer without self Pressure drop Area m² Air flow l/s Graph on page, use resistance, area and air velocity Air velocity m/s Pressure drop Pa Correction at disturbance according table on page 0 Factor Pressure drop after correction Pa 0 Hz Hz 0Hz 00Hz 000Hz 000Hz 000Hz 000Hz Graph on page, use resistance and air velocity Correction for gross cross section area Sound power level after the silencer (Logarithmical addition of self and sound power level after the silencer without self ) We reserve the right to make changes without prior notice

5 Pressure drop Follow the directions below and the adjoining graph. Calculate the gross cross section area a b in m². Go horizontal in the graph to the present air flow, l/s. Go up to the resistance achieved from the tables on pages. Read the pressue drop over the silencer, at straight duct connection before and after the silencer, (factor,0). For other modes of connection see the table for correction on page 0. Air flow velocity, which is used at the calculation of the self, can be read here. Total pressure drop [Pa] at duct/duct-connection Resistance 0 0 0, Air flow [l/s] Gross cross section area [m²], 0, 0, 0, 0, , 0 Air flow velocity [m/s] 0 We reserve the right to make changes without prior notice

6 Pressure drop Present pressure drop = Read pressure drop below factor D = The largest connection side (a or b) of the silencer. The table contains of a selection of the most coon disturbance cases. Before the silencer Distance before the silencer D D D 0 D 0 D D D D After the silencer Distance after the silencer Factor,0,,,,,,,,,,,,,,0 Chamber Kaar branch,0 Chamber aare,0 0 Logarithmic addition Increament to add to the highest db-value [db] Chamber Kaar Chamber aare, [db] Difference between db-values to be added 0 We reserve the right to make changes without prior notice

7 - 0,0 0,0 0,0-0,0 0,0 0,0 air duct systems per frequence band Outdoors Decide from the location of the silencer whether it is the supply or exhaust graph that shall be used. (Rule of memory - the side that leads away from the fan, i.e. at supply air the outlet graph is used and at exhaust air the in-take graph.) Intake Outdoor air Outlet Extract air Fan Fan Outlet Intake Room Supply air Exhaust air Sound power level after the silencer The sound power level after the silencer can be calculated for all frequences by a logarithmical addition of: "The self " and "The sound power level before the silencer". The shown example gives at 000 Hz: = db - db = db Sound power level before the silencer - the attenuation: db - db = db Logarithmic addition of and = db (See graph for logarithmical addition on page 0). Go horizontally into the present graph, at present air velocity, to the self. Then go vertically up to the crossing of the different frequency band lines. Read the self, at gross cross section area m², for each frequency band straight out to the left. In the example only the 000 Hz-reading is shown. 0 Add or subtract the correction for the present gross cross section area. at gross cross section area m² (Correction factor to other area according to above.) Air velocity (Velocity over gross cross section area.) in intake /DLDY Correction for gross cross section area: 0 db 0 db 0 db 0 db Hz Hz 0 Hz a b in m²: 0, 0, 0, 0, db(a) at gross cross section area m² (Correction factor to other area according to above.) 00 Hz 0 db khz 0 db khz m/s m/s m/s 0, khz khz 0 Air velocity (Velocity over gross cross section area.) in outlet /DLDY 0 db 0 db 0 db 0 db m/s m/s m/s, Correction for gross cross section area: a b in m²: 0, 0, 0, 0, Hz Hz 0 Hz 00 Hz khz khz khz khz 0 db(a) 0 0 m/s 0 m/s We reserve the right to make changes without prior notice

8 0 Width a Length l Static insertion attenuation / octave band [db] DLD DLDR Resistance Intake Outlet ,0,0, ,,, ,,0, ,,0, ,,, ,0,0, ,,0, ,,, ,,0, ,,, ,,, ,,, ,,, ,,, ,,, ,,0, ,,0, ,,0, ,,0, ,,0, ,,0, ,,0, ,,0, ,,0, ,,, ,,, ,,, ,,, ,,, ,,, ,0,0, ,,0, ,,, ,,0, ,,0, ,,0, ,,, ,0,0, ,,0, ,,0, ,,, ,,0, ,,0, ,,, ,,0, ,,, ,,0, ,,0, ,,, ,,, ,,0, ,0,0, ,,, ,,, ,,0, ,,0, ,,, ,,, ,,0, ,,0, ,,, ,,0, We reserve the right to make changes without prior notice

9 Width a Length l Static insertion attenuation / octave band [db] DLD DLDR Resistance Intake Outlet ,,, ,,, ,,0, ,,0, ,,, ,,, ,,0, ,,0, ,,, ,,, ,,0, ,,0, ,,, ,,, ,,0, ,,, ,0,, ,,, ,,, ,,, ,,, ,,, ,,, ,,, ,,, ,,, ,,, ,,, ,,, ,,, ,0,, ,,, ,,, ,,, ,,, ,0,0, ,,0, ,,0, ,,0, ,,0, ,,0, ,,0, ,0,0, ,,0, ,,0, ,,0, ,,0, ,,0, ,,0, ,,0, ,,0, ,0,0, ,,0, ,,0, ,,, ,,, ,,, ,,, ,,, ,,, ,,, ,,, 0 We reserve the right to make changes without prior notice

10 0 Width a Length l Static insertion attenuation / octave band [db] DLD DLDR Resistance Intake Outlet ,0,, ,0,, ,,, ,0,, ,,, ,,, ,0,, ,,, ,,, ,,, ,,, ,,0, ,0,0, ,,, ,,, ,,, ,,0, ,,0, ,,, ,,, ,,, ,,0, ,0,0, ,,, ,,, ,0,, ,,0, ,,, ,,0, ,,, ,,, ,,0, ,,0, ,,, ,,, ,,0, ,,, ,,0, ,,, ,,, ,,0, ,,, ,0,0, ,,, ,,, ,,0, ,0,0, ,,, ,,0, ,,0, ,,0, ,,, ,,0, ,,0, ,,0, ,,, ,,0, ,,0, ,,0, ,,, ,,0, ,,0, We reserve the right to make changes without prior notice

11 Width a Length l Static insertion attenuation / octave band [db] DLD DLDR Resistance Intake Outlet ,,, ,,0, ,,, ,,0, ,,, ,,0, ,,, ,,0, ,,, ,,0, ,,, ,,0, ,,, ,,0, ,,, ,,0, ,0,0, ,0,, ,,, ,,0, ,,0, ,,0, ,,, ,,, ,,0, ,,0, ,,0, ,,, ,,, ,,0, ,,0, ,,0, ,,, ,,, ,,0, ,,0, ,,, ,0,, ,,, ,,, ,,, ,,, ,,, ,,, ,,, ,,, ,,, ,,, ,,, ,,, ,,, ,0,, ,,, ,,, ,0,, ,,, ,,, ,,, ,,, ,,, 0 We reserve the right to make changes without prior notice

12 silencer DLDY Dimensioner B + 00 b a 0 Description DLDY is fitted with built-in side baffles located outside the fitting dimensions. The products can be manufactured in all standard duct sizes. For low-built solutions, see LRLB page. Design DLDY has an external shell of trapezoidal corrugated sheet for stability and reduced risk of natural oscillation. DLDY is designed for low air resistance with baffle combinations that dampen particularly low-frequency well. The type of insulation material is Lindtec which has been developed to provide good properties, low weight and to be cleanable. DLDY meets the requirements of air tightness class C. Tools for dimensioning and planning The software DIMsilencer is recoended for fast choise of silencer or a complete and fast sound calculation of the duct system. The software CADvent offers dimensioning in an environment with D-modelling. Computorised planning can be conducted with automatic presentation of levels, pressure drop etc. Published data as per ISO. l Ordering example DLDY TRA Product Width height a b Length l Accessories If alternative material is required, this shall be stated when ordering, e.g. aluminium zinc (AZ) and stainless acid-proof steel. The silencer is also available with the following accessories/ options. TRA = Non-insulated inspection hatch. TRB = Hatch intended for external insulation.* TRC = Hatch intended for external insulation.* TP = Absorbent covered with perforated sheet. AIA = 0 fire protection insulation. Note! a and b measures increase by 00. AIB = 00 fire protection insulation. Note! a and b measures increase by 00. The dimension of the hatches is adapted for cleaning and inspection of all baffle spacings. Manual dimensioning see pages. Insertion attenuation see pages. * Specify insulation thickness when ordering. We reserve the right to make changes without prior notice