Siemens manual Purging of CD 3002 using air blower, General, Installation

LDS 3000 Air blower Purging of CD 3002 using air blower

1.Purging of CD 3002 using air blower

1.1General

In application with high dust load and ash build-up in front of the lens in CD 3002 very high purging flows may be necessary. For these applica- tions an air blower producing flow rates in the 1000 ltr/min. range can be used. A typical application where this is preferable is in MWI (municipal waste incineration). This manual relates to the installation and operation of the air blower set supplied by Siemens Laser Analytics.

1.2Installation

An important issue is the counter pressure build up at the output of the air blower. It is vital to keep this as low as possible since the air flow is decreasing when the counter pressure increases – se the graph below.

Flow rate vs counter pressure

Counter pressure [mbar]

200

160

120

80

40

0

0 200 400 600 800 1000 Flow rate [ltr/min]

Flow rate vs counter pressure.

A large cross section of the air blower output and a short tube is param- eters that affects this in a positive direction. If a long tube must be used

–make sure it has a large diameter. The following diagram illustrates the flow changes with different output tubes and may serve as a guide when the set-up is designed. If the air blower is serving two sensors it is very important that the lengths of the tubes to the two sensors are equal. This ensures that the air is split 50/50 between the two.

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