AIRMAXX Axial Fan

System impedance of equipment

In accordance with the internal construction of the equipment to be called. The resistance will appear when passing air through the equipment

This will cause reduction of stationary pressure during the ventilation and is called the system impedance.

Consequently,it becomes necessary for us to give stationary pressure value higher than the impedance for performing ventilation to the equipment system impedance can be given using the following formula:

Δ P=Reduced pressure(mm-H2O)

Q=Air Volume(m3/min)

Δ P=KQn K5 Constant

N=index to be determine by air flow

N=1:laminar flow

N=2:Turbulent flow (Normally n=2)

The constant K here cannot be determined unless measure it by physically equipment.

Selection of the Fan

The selection of fan is done in according with following steps:

a) .Estimate the heat value (kw)of the heat source.

b) Determine the allowable temperature rise value Δ T

c) Assume the approximate ventilation volume in according with Formula(1)

d) Assumption of system impedance based on the ventilation of internal equipment of past data

e) Decide on the fan by referring to the Characteristic curve in Figure 2 from your catalog

f) Determine the adaptability of the fan by physically installing it is the equipment and measure the air temperature rise value Δ T or draft volume Q. if draft volume Q is insufficient, It is caused by the high system impedance , so it advisable to replace it with a higher quality fan

Measurement and measures against the Noises

Measurement of Noises

Measure it at 1.0 meters from the machine plane (at the central line of the air inlet )according to JIS-B8330(A characteristics)

Measures against Noises.

Although our fan motors are designed with special consideration of noises,sometime,it still can be affected by the user` s machine design to a large extent , so our attention is drawn to the following points:

a. Keep some distance between the object to be cooled and the inlet of the far. (Figure a -1)

b. When fittings are used ,pay attention not to cross each other with a spring .(Figure b -1)

c. When more than two fans are used, please keep then apart.(Figure c -1)

d. When finger guide is used, please keep it separated from the fan (We have kept some for this purpose.

Technical information of fan motor

Measurement of air volume and static pressure

In our company we have been measuring the air volume using the multi - nozzle chamber air volume measuring device of automatic recording type,which is in conformity with the highly reliable AMCA specifications(USA).

The error rate is below 1% theoretically.(based on AMCA),Also it is possible to measure the characteristics of the suction side as well as the blowing side ,( 54141732, 54140759,the values in catalog show the characteristics of the blowing side .)

Operation principle of measuring device

(in the case of blowing characteristics)

Principle of measurement

Determine the internal capacity of the chamber so that the speed of the air inside the chamber becomes less than 1m/sec,and let the air inside the chamber become stationary and measure the static pressure of with the static pressure:(+)impressing

Pressure;(-)suction pressure and the pressure difference between the front and the back nozzles (for air volume),and by means of the computing section output the result on the coder.

Computation formula

Air volume =60xcx/40D2 2g/r Δ pn(m3/min )

But C=Flow coefficient (variable due to wind speed )of nozzle

D=diameter of nozzle

R=air density =1.293*273/273=1*P/760kg/m3

(t=temperature C,P=air pressure mmHg)

G=9.8m/ses2

ΔPn=Nozzle differential pressure mm-H2O

Stationary Pressure Δ P=PA-P

Mm-H2O(PA=Air pressure in Chamber A,P=Atmosphere (pressure)Conversion Formula of Air Volume and Stationary Pressure P(inch -H2O)=0.0394P(mm-H2O)

Guide to search of fan motor

Computation of Required Draft Volume:

It becomes necessary to determine the draft volume when be force the equipment to be air cooled.Although it is advisable to option the air volume required formula:

Q(CFM)=35.31Q(m3/min)

Q(1/S)=16.67Q(m3/min)

Q=50*KW/ΔT--(1)

Q=Airflow required in m3/min

KW=Heat dissipated in kilowatt

ΔT=T2-T1(Allowable temperature rise)in 0C

(T1=Air temperature at air inlet)

(T2=Air temperature at air outlet)

For example:6.25m3/min of airflow is required for a system that disspates 1KW and allow 80C(ΔT) temperature rise.

General Data:

Frame/Housing :Aluminum&Plastic UL 94v-0
Impeller :Plastic PBT(UL 94v-0)
Bearing System :Ball beating or sleeve bearing
Insulation Resistance : Above 100MΩ,DC500V
Dielectric withstand voltage : AC 700V one second
Operating Temperature :Ball bearing : -300C~700C
Sleeve bearing :-100C`700C
Life expectancy :Ball bearing :over 50,000hr(At250C)
Sleeve bearing :over 30,000hr(At 250C)

3-Inch AM808025 (80mm x 80mm x 25mm Axial Fan)

AC AXIAL FAN

Features:
- Reliable shaded-pole AC motor construction.
- The frame of AC type is die-cast aluminium painted black for moisture and corrosion resistance.
- Precision, Life-lubricated ball bearing system.
- Operation temperature -20 to 80'C.
- The impeller is injection molded non-flammable black thermoplastic UL 94V-0 rating.
- Insulation CLASS B.