Figure 1-17. Venturi Schematic.

Figure 1-17.

Venturi Schematic.

Heat Exchanger (fig. 1-18).

This system has the heat exchanger located downstream of the flow

limiting venturi large outlet and prior to the condenser.

The heat

exchanger has a bleed air flow length of 15.65 in.

Manufacturers

make this single-flow, cross-flow, plate-fin type heat exchanger

entirely of an aluminum alloy.



Operation (fig. 1-19).

Bleed air flows from the flow

limiting venturi at a maximum of approximately 200 cfm with

a pressure of 35,F ƒ2,F maximum.

The bleed air flows

through the passageways lined with rectangular fins set in

an offset configuration, much the same as the precooler.

The cooling air flows through the heat exchanger in

passageways lined with fins placed in a wavy configuration.

The heat exchanger uses outside air as the cooling air. A

fan (to be described later) draws the cooling air through

the heat exchanger.

The cooling air flows through the

deswirl vanes to the precooler and out the exhaust exit.

The deswirl vanes remove any turbulence created by the fan.

OD1705