Author: Chia-Chieh Yu, An-Yi Ma (2004-09-15);
recommended: Yeh-Liang Hsu (2004-09-15).
A functional prototype of DeIcer
DeIcer is a
hand-held heating device for car drivers to melt ice in keyholes, frozen doors
and windows in winter, by blowing warm air on them. It is used remotely, and
does not have any power cable.
work, we have confirmed that the required temperature of the outlet air can be
achieved using a mixture of propane and butane as fuel. This document describes
a functional prototype of DeIcer. The purpose of the functional prototype is to
integrate all components to demonstrate the function of DeIcer.
Layout drawings of DeIcer
Figure 1-3 show
the layout drawings of DeIcer in different views. Figure 4 shows the 8
components in DeIcer: (1) protective cap, (2) flame housing, (3) burner, (4)
regulator, (5) base plate, (6) blower, (7) blower holder, (8) packaging case.
The blower (6) suck cold air from outside and blows it on the heating chamber
(components (1)-(5)), then warm air comes out of the outlet.
Figure 1. The integration of DeIcer
Figure 2. View 1 of DeIcer
Figure 3. View 2 of DeIcer
Figure 4. Components of DeIcer
technique in DeIcer design is that, how to build a combustion furnace as heat
source (electrical heating has been ruled out since DeIcer should not carry any
power cable), keep the combustion stable, provide enough heat, while air is
constantly blown on it at 3.5 m/sec.
Figure 5 shows
the heating chamber module of DeIcer, and Figure 6 shows the 5 components in
the heat source. Instead of blowing air directly on the flame, the blower blows
air on flame housing (5). The shape of the flame housing can be cylindrical or spherical,
to provide the best efficiency. Ventilation holes on the flame housing and the
protective cap (1) are carefully designed so that the combustion is complete
and stable under the air flow, and flame will not come out from the outlet. The
leading wire of the ignition mechanism is integrated with the burner (3) and
gas regulator (4) for safe and convenient operation by the user.
Figure 5. Heating chamber module
Figure 6. Five components of the heat source
The functional prototype
Figure 7 shows
the functional prototype of DeIcer. There are 4 modules in the functional
prototype: the heating chamber module, the blower module, the triggering
mechanism module, and the sensing module. The 4 modules are described in
Figure 7. Integration of functional prototype
The heating chamber module
shows the heating chamber (80mm×71.5mm×170.5mm) which is made by bakelite and asbestos. The heat source is
contained in the heating chamber. As described in the previous section, there
are 4 components in the heat source: (1) protective cap, (2) flame housing, (3)
burner, (4) regulator, and (5) base plate. Figure 9 shows the burner and the
regulator. The regulator can be accurately controlled to a fix gas flow rate.
Figure 8. The heating chamber
Figure 9. The burner and the regulator
shows the protective flame housing. The protective flame housing is made of copper,
which is a good conductive material and is not easy to melt. It is designed to
cover the flame to make it steadier, and to spread the heat of the flame to the
housing. A leading wire of the electrical ignition is embedded in it. Figure 11
shows the gas can, which can be bought from mountain climbing stores.
Figure 10. The protective flame housing
Figure 11. The gas can
The blower module
shows the blower. The blower of a regular hairdryer is used. Its maximum outlet
speed is 3.5m/s.
Figure 12. The blower
The triggering mechanism module
shows the triggering mechanism module. The electrical ignition is used to
ignite the burner. A button is designed to make an electrical arc and to
control the blower. Batteries provide electricity to the electrical ignition
and the blower.
Figure 13. The triggering mechanism module
The sensing module
sensing module is for measuring the performance of the prototype, and will not
be included in the final product. A thermal couple measures temperature Tin
of the input air. Another thermal couple measures temperature Tout
at the air outlet. A thermal meter shows the difference between Tin
and Tout, and this temperature change is recorded every 1
are several restrictions when designing the prototype. The blower and the
burner restrict the size and shape of the heating chamber and the protective
flame housing. Both the burner and the gas can, which were bought from the
mountain climbing store, are too big for our purpose. We need to customize
these two components, but this is beyond our prototyping ability. The gas
regulator needs to be customized too, so that it can be integrated with the
Figure 14 shows
the operation procedures of the functional prototype. First, push and hold on
the start button lightly to get the electrical arc. Then, turn on the regulator
to release gas. After firing, pushes the start button to start the blower. To
turn off the DeIcer, turn off the regulator first, and then push the start
button again to turn off the blower. Again, if we can customize the gas
regulator, we should be able to integrate it with the triggering mechanism.
Figure 14. The steps of the operation procedures
Table 1 shows
the result of three different flow rates under the same testing condition. The
room temperature is 27oC. As in the previous experiments, the temperature
of the outlet air rises rapidly and it keeps increasing slowly. In Table 1, the
mean temperature rise for 30 seconds after 60 oC is defined as DTm. As shown in Table 1, DTm decreases as air outlet speed V
Table 1. The testing result of function prototype
3.6V (Three batteries)
4.8V (four batteries)
6V (Power supply)
Several issues need to be confirmed
in order to go on with the design of the 2nd generation prototype of
In the functional prototype, we
integrated the components to demonstrate their functions, without confirming
their layout. There are two possible design layout of DeIcer. Figure 15 shows
the parallel layout of DeIcer. Figure 16 shows the vertical layout of DeIcer.
The parallel design layout is analogous to the shape of digital camera. The
vertical layout is analogous to the typical hairdryer.
Figure 15. The parallel design layout
Figure 16. The vertical design layout
The construction of the heating
chamber is the critical design of DeIcer. The profession manufacturer called
Fu-Ray will help us find the proper type of burner and gas regulator.
The gas can is also a problem
of DeIcer. The gas can should be able to work over 30 minutes, and the size of
the gas can should be as small as possible. The fuel of mix of Propane and
Butane should be used in –15oC.
The outlet temperature changes
should be controlled in 85oC.
The triggering mechanism should
be the one button to start the DeIcer.
The professional manufacturer
called Raeider will provide a new type of fan, which can work in AA batteries
and blow strong flow for 30minutes.
The isolation materials should
be added to prevent users from burning their hands and DeIcer.
Safety issues need to be