MICROWAVE HOT WATER HEATER

CHAUFFE-EAU A MICRO-ONDES

English Abstract

Abstract of the Disclosure

This invention relates to an on line and on demand
microwave hot water heater with variable flow rates
according to magnetron power levels up to 2450
megahertz. The heated water flow rates lie in a range of
to 25 gallons per minute. A convoluted waveguide
receives electromagnetic energy from the magnetron and
converts it to thermal energy and temperature rise for
the water that flows through it. This is a total
absorption of the microwave energy, that is, there is no
energy leakage.

Claims

The embodiments of the invention in which an exclusive
property or privilege is claimed are defined as follows:


1. A microwave hot water heater comprising a magnetron
energy source, a water cooling jacket superposed on
the magnetron housing, laterally extending water
carrying wave guides, a cold water inlet connected
to an upper portion of the wave guide through a
microwave isolator stub, a lower terminal end of the
wave guide connected to a hot water outlet, a power
level thermostat in the hot water outlet and an
outer containment housing with plug-in means to an
electrical supply of 110/220 volts.

2. The apparatus of claim 1 wherein the heated water
exits the system through a termination stub and
wherein hot water supply rates vary according to
magnetron power levels and lie in a range of 5 to 25
gallons per minute.

Description

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This inventinn relates to a microwave operated water
heater that has been developed for residential,
commercial or industrial use, and that eliminates the hot
water storage tank.



The heater unit has a cold water inlet at an upper end of
its housing and a hot water outlet at an opposite upper
end of its housiny. It will only operate while water is
flowing through it.



The housinq contains a water flow path exposed directly
to microwave power levels emanating from a 2450
mega-hertz maqnetron as the water passes through wave
guides in the form of reverse bend tubes.
Electromagnetic energy is converted to thermal energy
thus increasing the water's temperature.



The water flow rate, the mannetic power levels, the total
length of the wave guide and a thermostat at the hot
water outlet constitute the variables.



It has been found that hot water supply rates of 3, 5, 10

and 25 yallons per minute are obtainab~e because of the
flexibility of the controls for supplying hot water on
demand.



In operation, incoming cold water will go firstly through
the magnetron to supply the cooling and a preliminary
preheat for the water. When a water supply tap is
opened, a flow switch will power the magnetron filaments
and prepare the magnetron for the application of the high
voltage. A time delay switch will then cause the high
voltage to be applied when the magnetron is ready for


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hiqh power operation. The unit will only operate while
water is flowing througll it.



Incoming cold water, after passing through cooling stages
of the maqnetron, flows throuah a microwave isolating
stub and into the convoluted wave guide. The water is at
the desired temperature and exits from a microwave
termination point at the thermostatically controlled
temperature.



In further description of tlle invention reference is made
to the accompanying drawings wherein:



Figure 1 is a side elevation of the heater unit.



As shown in Figure 1, the heater housing 1 contains a
flow path 2 from a cold water inlet 3 to a hot water
outlet 4 at an opposite end. Water entering at 3 passes
into a water coolinq jacket 5, this jacket is superposed
on and connected with a 245û mega-hertz magnetron 6,
which is the energy source. The cold water inflow is
subjected to a preliminary preheat by the magnetron.

This is initiated by water flow switch 7 when a tap is
opened. A time delay switch will then bring the
magnetron up to full voltage.



The water to be heated follows a sinuous path with 1 sn
bends at 2a. It is in this tuhular path that
electromaqnetic energy is converted to thermal energy
with the concomitant temperature rise for the water. In
further description, the sinuous path is more aptly
referred to as the wave guide. The heated water exits
through outlet 4 at a temperature dictated by power level


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-- 3



thermostat S. A microwave isolator stuh 9 at the
beginning of the wave guide and a microwave termination
seal 10 at the end of the wave guide ensure that there is
no microwave energy leakage from the system. Microwave
power levels heat the water in stages until cold water is
heated to a particular maximum. Power supply and power
level controllers are shown in block diagram at 11.
Similarly, a switch panel is shown at 12. The heater
unit is connected to 110/220 voltage mains and proximate
to sink or tub.

Representative Drawing