BS 848-9:2006 pdf download – Fans for general purposes — Part 9: Tolerances, methods of conversion and technical data presentation
This International Standard specifies performance tolerances and the technical data presentation of industrialfans of all types. lt does not apply for fans designed solely for low-volume air circulation, such as those usedfor household or similar purposes (ceiling and table fans, extractor fans, etc.).For jet fans refer to ISO 13350.
The upper limit of fan work per unit mass is normally 25 kJ kg 1, corresponding to an increase of fan pressureof approximately 30 kPa for a mean density in the fan of 1,2 kg m-3.For higher values, agreement is to bereached between the supplier and the user.
This International Standard embraces the four installation categories defined in ISO 5801:
free inlet, free outlet;
Bfree inlet, ducted outlet;cducted inlet, free outlet;Dducted inlet, ducted outlet.
The performance of a fan can vary considerably with the installation category it is operating within. Therefore,these categories form an important part of the definition of the fan’s technical data presentation.
NOTE International acceptance of the four installation categories provides the opportunity to base a contract on themost appropriate fan category for the end user and the system designer.Correspondingly,the likelihood of the fanproviding the agreed performance,without compromise or concession, is enhanced.
2Normative references
The following referenced documents are indispensable for the application of this document.For datedreferences,only the edition cited applies. For undated references,the latest edition of the referenceddocument (including any amendments) applies.
ISO 5801:1997, Industrial fans — Performance testing using standardized airwaysISO 5802,Industrial fans — Performance testing in situ
ISO 13347-1,Industrial fans -Determination of fan sound power levels under standardized laboratoryconditions — Part 1: General overview
ISO 14694, Industrial fans —Specifications for balance quality and vibration levelsISO 14695,Industrial fans — Method of measurement of fan vibration
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
NOTE In some cases, more complete definitions are to be found in ISO 5801, ISO 5802 and ISO 13349.
industrial fan
fan other than that used for household or similar purposes such as air circulation, climatization
NOTE For the purpose of this International Standard and other industrial fan standards, a household fan is defined as having a single-phase motor operating at a maximum of 250 V and 16 A. With a sufficiently soft start, this equates to an input power of not more than 3 kW.
series-produced fan
catalogue fan
fan whose detailed performances is widely available in a catalogue (electronic and or printed), and which is frequently manufactured in significant quantities and available on short delivery
average stagnation pressure at a section x
p sgx
sum of the conventional dynamic pressure, p dx , corrected by the Mach factor coefficient, F Mx , at the section,and the average absolute pressure, p x
5 Performance tolerances for purpose-designed fans
5.1 Information to be provided by the purchaser
5.1.1 Operational
The following information shall be provided.
a) Volume flow rate, q V , rate at the fan inlet or mass flow rate q m .
b) Total pressure increase, p t , between fan inlet and outlet, or static pressure increase, p s , at a specified discharge area.
c) Distribution of total pressure losses in the system between inlet and outlet side of fan.
d) Absolute pressure at fan inlet.
e) Density, ρ 1 , of handled fluid at fan inlet.
f) Temperature of the gas handled at the fan inlet for normal operation relevant for the fan performance, and the maximum and minimum temperatures for which the fan is to be designed.
g) Dust, mist or vapour content of gas at fan inlet for normal operation, the properties of these, and their maximum content. Information as to whether the dust, mist or vapour is combustible, noxious, aggressive or sticky.
h) Maximum permissible A-weighted sound power level, in A-weighted decibels, as specified in ISO 13347-1.
i) Maximum permissible levels of mechanical vibration in service, as specified in ISO 14694.
j) System characteristic, if necessary.
k) Design speed cycles: i.e. the number of speed cycles per 24 h, the range of speed, if variable speed, plus the total number of start-stops the fan is to be designed for.
l) Other specifications (e.g. preferred rotational speed, type and range of control, orientation of the inlet and discharge, impeller rotation, as viewed from the driver). See ISO 13349.