[0001] The present invention relates to a method and apparatus for heating water or similar
incompressible liquids in flow heaters, and in particular it relates to a flow heater
apparatus with an electro-acoustic tubular heating element using resonant heating
of the liquid. The heater containing an electro-acoustic heating element is applied
in devices for water heating by flow, especially in household devices for hot utility
water receiving and in devices for hot industrial water receiving.
[0002] In times of global warming, taxation of carbon dioxide emissions as well as electricity
costs rising, it has become extremely important to find ways to save electricity.
A hot water storage tank in a household or office is usually the largest single energy
consumer.
[0003] Various methods of water heating by means of electricity are known, of which conventional
resistance heating elements are considered the most efficient way to heat water and
other liquids. Electric water heaters preferably produce hot water without consuming
the fuel supplied for on-site combustion. Electric heaters may include an internal,
bare heating element, which most often may be a resistance wire helix or an electrical
resistance element in a glass or ceramic housing. The heat is transferred from the
electric resistance heating element to the working liquid by the conductive heat of
various types of heaters origin.
[0004] Apart from conventional resistance heating elements, there are heating systems that
use other physical phenomena involving electricity, which, according to the inventors,
are more efficient and use less energy to heat the same amount of liquids.
[0005] In solutions with a bare heating element, a series of metal ions are released from
the heating elements into the heated water, which in combination with ions present
in water form salts of various solubility. These salts, combined with chemical compounds
dissolved in heated water at high temperature, cause the formation of deposits on
the heating elements and the housing of the heaters, which causes erosion and corrosion
of the heating elements and their housings, and ins consequence their accelerated
consumption. In the application description P.426906, the inventors describe a noncorrosive
and erosion-free flow-through heating boiler, in which a method of application a suitable
steel is described, which eliminates these phenomena, or at least reduces them to
a large extent.
[0006] Heating systems, in which electric energy can be used to generate infrared rays,
are less favorable in terms of electrical efficiency.
[0007] In some embodiments of
WO2013 / 102830 an ultrasonic converter has been used to increase the efficiency of the heating system
and thus reduce costs. The ultrasonic generator and the heating element are preferably
connected by a common electrical input so that the device may be used to replace a
conventional heating element.
[0008] Patent
PL 220668 discloses a method and a device for application of this method of glycol heating
by means of an electrode heater operating in two steps due to the sensitivity of glycol
to high temperatures.
[0009] In the first step, the glycol is heated with electrodes in the so-called short cycle,
and after the liquid is heated to the set temperature, a full cycle is started and
the liquid is heated with electrodes in the entire tank. The essence of the device
according to the patent
PL 220668 consists in the fact that the steel electrodes of the heater immersed in glycol are
connected to the AC mains supply circuit with the frequency of the industrial mains
and can be made of steel pipes or bars. In the utility model application W. 124769
Electro-dynamic conductive heater, a device in which in the inner space of the heater there are electrodes heating the
heating medium was presented. The device can work as a stationary or flow heater.
[0010] A similar solution applying other physical phenomena is presented in the devices
described in the applications
US2014270723 and
PL424812.
[0011] The purpose of the invention is to provide a construction of heating element for
a flow heater of any design applied for heating liquids, using electro-acoustic resonance
resulting from the submerged electrodes supplied with low-frequency alternating pulsed
current.
[0012] The essence of the solution is the fact that the electro-acoustic heating element
using alternating electric current for the flow heater heating water-based liquids
contains an electro-acoustic resonator causing heating of the liquid in which it is
immersed. The heating element consists of three electrodes, of which the center tube-shaped
electrode is the resonating element, and the two external tubular electrodes are the
buffering electrodes.
[0013] The center electrode is connected to the phase wire, the current wire, and the two
external electrodes are connected to the neutral wire. In order to ensure high resistance
to corrosion and destructive metal salts deposition, the electrodes are made of austenitic
steel with the symbol AISI 316L, preferably of chromium-nickel-molybdenum steel. The
outer and inner surfaces of the electrodes are ground and polished, thus preventing
the formation of deposits on their surfaces.
[0014] The electrodes of the heating element are connected to the AC mains circuit with
a frequency of 50 - 60 Hz and a voltage of 110-240 V. The electro-acoustic heating
element may be connected through a switch and an inverter to other sources of electric
current, preferably obtained from sources of so-called renewable energy.
[0015] The electro-acoustic heating element according to the invention may be a component
of a multi-element heating set.
[0016] The invention relates to an emission-free heating technique, which can be used in
households and industry. The solution in which austenitic steel in a three-electrode
system has been applied is a new solution and allows to increase the efficiency of
the heating element as well as the boiler in which it was installed. Additionally,
it prevents rapid corrosion and progressive erosion of the boiler in result of the
mineral compounds deposition on the surface of the electrodes.
[0017] The design of the device is shown in the drawings, in which Fig. 1 shows a sectional
view of the heater, while Fig. 2 shows a longitudinal section A-A of the device, with
attached detailed part A, Fig3. Figure 4 shows the cross-section of the heater B-B.
[0018] Marked in the figures:
1 - internal resonating electrodes
2 - external buffering electrodes
3 - electrode fixing caps
4 -ceramic / ebonite pads regulating mutual distances between the electrodes
5 - the phase current connection to the tubular resonating electrode inside the device
6 - the residual current connection to the tubular buffering electrode inside the
device
7 the neutral current connection to the tubular buffering electrode and the resonating
electrode outside the device
8 - heater housing
L - distance between electrodes.
[0019] The solution in which austenitic steel is applied in a system of three tubular electrodes,
of which the electrode
1 is the resonating electrode, and the pipes
2 are the two external and internal buffering electrodes of the heating element. Electrodes
1 and
2 are separated by insulating spacers
4 made of a material insulating electric energy, preferably made of glass, porcelain
or ebonite. Caps
3 fasten the electrodes inside the device and at the same time they fasten them to
the housing, ensuring the insulation of individual electrodes and their stability
when connected to the housing. The distance between electrodes is 3 - 5 mm. The length
of the device according to the invention is less than or equal to 1000 mm.
[0020] The connections of the power cables
5 and
6 allow the current to be supplied to the electrodes of the heating element. Connection
5 corresponds to the phase current and connection
6 corresponds to the neutral circuit. The entire power supply is provided by the connection
7 located on the housing through the cap
3.
[0021] The presented tubular heating element is a new solution ensuring more efficient application
of electricity for heating liquids that can be used in households and for industrial
purposes.
[0022] The construction and application of the device that is the subject of the invention
application is described in the embodiment. The presented device is a laboratory device
used during the tests concerning the electrical efficiency of the device.
Example 1
[0023] An embodiment of an electro-acoustic heating element device according to the invention
is shown in Figures
1 and
2. The heater shown in Fig. 1 comprises an electro-acoustic heating element consisting
of two external buffering electrodes
2 made of austenitic steel with the symbol AISI 316L, with the following dimensions:
length of 70 mm and thickness of 2 mm. At the of electrodes a connection was made
to connect the neutral electric wire
6.
[0024] The central resonating electrode 1 was made of austenitic steel with the symbol AISI
316L, chromium-nickel-molybdenum steel X2CrNiMo17-12-2 / 1.4404 with dimensions of
60 mm x 8 mm and a thickness of 2 mm.
[0025] At the end of the electrode a phase connection was made for the electric wire
5. Buffering electrodes and resonating electrode have been connected through a hole
with a diameter of 6 mm, with a plastic screw
7, separating them by the ring-shaped spacers
4 made of porcelain, with a hole sized to match the outer diameter of the electrodes
and a thickness of 3 mm.
[0026] In the efficiency test of the heater with an electro-acoustic heating element, two
independent experiments were performed with the use of the same parameters of the
experiment. A heater with an electro-acoustic heating element and a typical electric
heater have been used to heat the water. Devices with a power of 1850 W have been
connected to the power of 7.8 A and 230V. Water with an initial temperature of 25°C
has been used. After 10 minutes of heating water with a volume of 100 1 and a liquid
flow of 10 1 / min, the temperature for water heated by a heater with an electro-acoustic
heating element was 60°C, and for a typical heater, 35°C.
[0027] The result of the experiment fully confirms the greater efficiency of the heater
with electro-acoustic heating element The invention described above is only a description
of an embodiment and it does not limit the methods of making other modifications and
dimensions of the device in the spirit of the invention essence and the data set out
in the claims.
1. An electro-acoustic heating element using alternating current for a flow heater for
heating water-based liquids, characterized in that it comprises an electro-acoustic tubular resonator for heating the liquid in which
it is immersed.
2. Electro-acoustic resonator according to claim 1, characterized in that it has three tubular electrodes, heating elements, of which the middle one is a resonating
element, and the two extreme electrodes are buffering electrodes.
3. The electrodes according to the claim 2 characterized in that the central one is connected to the phase conductor, the current one, and the two
external electrodes are connected to the neutral conductor.
4. The electrodes according to the claim 2, distinguished by that they are made of austenitic
steel with the symbol AISI 316L, preferably made of chrome-nickel-molybdenum steel.
5. The electrodes according to the claim 2, distinguished by that their inner surface
as well as the outer one is ground and polished, thus preventing the formation of
salt deposits on their surfaces.
6. The electrodes according to the claim 2, distinguished by that they have the shape
of a tube with an outer diameter less than or equal to 1000 mm.
7. The electrodes according to the claim 2, distinguished by that the thickness of metal
electrodes is less than or equal to 10 mm.
8. The electrodes according to the claim 2, distinguished by that the two external buffering
electrodes are 5-10% longer than the centre resonating electrode.
9. The electrodes according to the claim 2, distinguished by that they are separated
by ring-shaped spacers made of porcelain, glass, ebonite with a hole of the dimensions
matching the outer diameter of the electrodes and a thickness less than or equal to
50 mm.
10. An electro-acoustic heating device according to the claim 1, distinguished by that
the electrodes of the heating element are connected to an industrial AC mains circuit
with a frequency of 50 - 60 Hz and a voltage of 110-240 V.
11. The electrodes according to the claim 1, distinguished by that they are supplied with
alternating current of a power less than or equal to 20,0 kW.
12. An electro-acoustic heating device according to the claim 10, distinguished by that
the electrodes of the heating device can be connected via a switch and an inverter
with other sources of electric current, preferably obtained from sources of the so-called
renewable energy.
13. An electro-acoustic heating device according to the claim 1, distinguished by that
it may be a component of a multi-element heating set.