Shrinkfast 998 UL, Operating, Field Maintenance, And Parts Manual

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PRINCIPLES OF OPERATION
The Model 998 offers an improved jet pump using a multi nozzle orifice. The jet
pump is shorter and more efficient with the benefits of a wider and more powerful
heat pattern. The 998 is basically a simple jet engine, the high energy exhaust of
which is used to pump and heat the surrounding air and deliver an air blast of high
velocity and moderate temperature. Its’ effectiveness is based on the high level of
technical development which has gone into optimizing each stage of operation:
1. Jet Pump. The propane jet (A) draws the correct amount of combustion air
through the air inlet (B). They mix together in the straight section (C).
2. Compression. The conical section (D) turns speed into pressure.
3. Combustion. The combustion process is carried out inside the combustor (E).
The flame holder (F) prevents flashback (where the flame travels back into the jet
pump) and the flame out (where the flame is blown out of the combustor).
Another proprietary function of the flame holder is to achieve the effect of
maintaining cold combustor walls in spite of the fact that the combustion is
substantially completed inside the combustor. This is done by imparting a swirl to
the mixture. During combustion, the burned portion of the mixture expands, and
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