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(11) | EP 1 566 598 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Instant electric water heater |
| (57) The heater has a sealed internal deposit (2) housing, submerged in heat-transfer
oil, an electric heater group (3) heating the heat-transfer oil and therefore the
water circulating through two coils (4, 5) surrounding said heater group (3). Both
coils (4, 5) share an external cold water inlet (6) and they have a heated water outlet
(20) going to an external deposit (1) surrounding the internal deposit (2). The heated water exits the external deposit (2) through a hole (7) and converges in a thermostatic valve (14) with an external cold water inlet (19) where they are mixed to then pass through a pressure switch (15) connected in tandem to a probe (16) controlling the temperature of the electric heater group (3). The external deposit (1) is surrounded by an insulating layer (12). The heater supplies a continuous hot water flow for domestic or industrial use, even for feeding water heating units. |
OBJECT OF THE INVENTION
[0001] The object of the invention consists in an instant electric water heater, of reduced dimensions, for both domestic and industrial use, maximally optimizing its yield with a minimum energy consumption and continuous hot water flow, without temperature or flow losses occurring.
BACKGROUND OF THE INVENTION
[0002] Electric water heaters usually contain a large volume of water which must remain enclosed, ready for use, in a relatively isolated deposit, with the subsequent expense for maintaining the temperature of that large water mass.
[0003] Furthermore, once hot water consumption has begun, the hot water is limited over time, since once the hot water stored in the deposit is consumed, the heater is not able to heat water at the rhythm of consumption, therefore the water temperature abruptly drops, with the corresponding inconveniences and discomforts.
[0004] These electric heaters take a fairly long time from when they are connected until they are able to supply hot water at a certain temperature.
[0005] Conventional heaters have a large volume, often difficult to hide or conceal with the furniture, and are therefore difficult to install in a special area.
DESCRIPTION OF THE INVENTION
[0006] The present invention is an instant water heater of continuous cyclic rate and reduced dimensions, it is very useful for preventing the previous drawbacks and for replacing large boilers, normally gas and potentially dangerous boilers, supplying hot water for consumption, and at the same time, acting as a hot water supply for heating units.
[0007] Heating of the water is carried out by means of an electric heater group with a fork shape or the like, submerged in a heat-transfer oil, or a similar fluid, which is kept hot and at a constant temperature due to the effect of the heater, this heat-transfer oil being of a minimum volume. The water to be heated circulates through two shunted coils surrounding the heater group, also being submerged in the heat-transfer oil. This heater-coil-heat-transfer oil assembly is housed in a suitably sealed and pressurized internal deposit.
[0008] To maintain water flow and to minimize pressure and flow losses, the two shunted coils are provided with a single common external water inlet, whereas the outlet of each coil is independent, which outlet is arranged outside the internal deposit, on which a second deposit, also sealed and of reduced dimensions to prevent thermal inertia, has been installed; both water outlets of the coils are mixed in this external deposit and are homogenized until their outlet, as hot water, through a hole made in the external deposit.
[0009] A hollow bushing incorporating a stopper and which keeps the two deposits equidistant passes through the two deposits, at the same time allowing the filing of the heat-transfer oil and pressurizing of the internal deposit.
[0010] The hot water outlet of the external deposit, together with a direct cold water inlet like the one entering the heater to the coils, are collected by a thermostatic valve, which regulates the final water outlet temperature, thus always keeping it uniform.
[0011] The outlet of this thermostatic valve is connected in tandem to a pressure switch which, taking the temperature data collected by a probe installed inside the internal deposit as a reference, will provide the corresponding connection or disconnection instructions to the heater group.
[0012] An insulating layer surrounding the external deposit has been arranged to prevent the system from losing heat to the outside.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The following figures are included to facilitate understanding of the invention:
- Figure 1 shows an exploded perspective view of the main components of the electric water heater.
- Figure 2 shows an upper view of the heater according to a section thereof along the horizontal plane containing the axis of the internal and external deposits of the heater.
PREFERRED EMBODIMENT OF THE INVENTION
[0015] A preferred embodiment of the invention, which is to be understood in a broad and non-limiting sense, is detailed below.
[0016] Figure 1 shows the most important components of the instant electric water heater: an external deposit (1), an internal deposit (2) housing a heater group (3) surrounded by two shunted coils (4, 5), an external water inlet (6) common to both coils reaching them and passing through the walls of both deposits (1, 2). The external deposit (1) is provided with a hot water outlet (7) connected, together with a cold water conduit (19), to a thermostat (14) in tandem with a pressure switch (15) connected to a probe (16) measuring the temperature of the heat-transfer oil of the internal deposit (1) .
[0017] Figure 2 shows the circulation of water in the heater. The water to be heated circulates through two coils (4, 5) surrounding an electric heater group (3) of those having a fork shape or the like. Both the electric heater group (3) and the coils (4, 5) surrounding it are submerged in a heat-transfer oil or similar fluid which is kept hot and at a constant temperature due to the action of the electric heater group (3), this fluid being of a minimum volume; all this housed in a suitably sealed and pressurized internal deposit (2) .
[0018] A temperature measuring probe (16) is installed in the internal deposit (2) to control the temperature of the heat-transfer oil.
[0019] The two coils (4, 5) are arranged in shunt with a single external cold water inlet (6), which is shared between the two coils, and two independent water outlets (20); this allowing minimization of losses of pressure and flow to the outside of the internal deposit (2). The internal deposit (2) is surrounded by a sealed external deposit (1) of reduced dimensions to prevent thermal inertia, and it is where the two exiting water flows of the internal deposit are mixed and homogenized, and where the water continues to be heated since it is in contact with the walls of the internal deposit (2), which is hot because it contains the heat-transfer fluid heated by the heater group (3).
[0020] The external deposit (1) is provided with a hole with a water outlet (7) through which the heated water is evacuated.
[0021] The cold water inlet (13) going into the heater splits into two channels, the first channel is the water inlet (6) to the coils (4, 5) and the second channel is a conduit (19), the opposite end of which ends, together with the hot water outlet (7) of the external deposit (1), in a thermostatic valve (14), where both hot and cold water currents are mixed, and where the temperature of the outlet water is finally regulated, thus always keeping it at a uniform temperature.
[0022] The thermostatic valve (14) outlet is connected in tandem with a pressure switch (15) which is connected to the probe (16) for measuring the temperature of the heat-transfer oil of the internal deposit (2). The pressure switch (15) will connect or disconnect the heater group (3) according to the data of the heat-transfer oil temperature collected by the probe (16).
[0023] After passing through the pressure switch, the suitably heated water passes to the network or is directly used.
[0024] A hollow bushing (8) incorporating a stopper (9) passes through the two external (1) and internal (2) deposits, and keeps the two deposits (1, 2) equidistant, at the same time allowing the filling of fluid and pressurizing of the internal deposit (2).
1. An instant electric water heater, characterized by a sealed and pressurized internal deposit (2) which houses, submerged in a heat-transfer
oil: a temperature probe (16), an electric heater group (3) surrounded by two shunted
coils (4, 5) sharing a single external cold water inlet (6), and each one has a heated
water outlet (20) to the outside of the internal deposit (2). The internal deposit
(2) is completely surrounded, sharing a single base (18) or another connection element,
by a sealed external deposit (1) provided with a heated water outlet (7) ending in
a thermostatic valve (14) together with the end of an external cold water conduit
(19). The outlet of the thermostatic valve (14) is connected in tandem with a pressure
switch (15) connected to said temperature probe (16).
2. An instant electric water heater according to claim 1, characterized in that the electric heater group (3) is of those having a fork shape.
3. An instant electric water heater according to previous claims, characterized in that the cold water inlet (6) to the coils (4, 5), and the cold water channel (19) to
the thermostatic valve (14) are the two bifurcations of a single external cold water
inlet (13).
4. An instant electric water heater according to previous claims, characterized in that the external (1) and internal (2) deposits are equidistant and a hollow bushing (8)
incorporating a stopper (9) passes through them.
5. An instant electric water heater according to previous claims, characterized in that the external deposit (1) is surrounded by an insulating layer (12).
Amended claims in accordance with Rule 86(2) EPC.
1. An instant electric water heater, of the kind that has a sealed and pressurized internal
vessel (2) which houses, submerged in a heat-transfer fluid, an electric heater group
(3), surrounded by two shunted coils (4, 5), said coils having a inlet (6) for the
fluid to be heated and each coil having an outlet (20) to the outside of the internal
vessel, the internal vessel (2) being completely surrounded, sharing a single base
(18) or another connection element, by a sealed external vessel (1) provided with
a heated water outlet (7) characterized by, said inlet (6) is shared by the two shunted coils (4,5), and the heated water outlet
(7) ends in a thermostatic valve (14) together with the end of an external cold water
conduit (19). The outlet of the thermostatic valve (14) is connected in tandem with
a pressure switch (15) connected to a temperature probe (16) housed in the internal
vessel (2).
2. An instant electric water heater according to claim 1, characterized in that the electric heater group (3) is of those having a fork shape.
3. An instant electric water heater according to previous claims, characterized in that the cold water inlet (6) to the coils (4, 5), and the cold water channel (19) to
the thermostatic valve (14) are the two bifurcations of a single external cold water
inlet (13).
4. An instant electric water heater according to previous claims, characterized in that the external (1) and internal (2) vessels are equidistant and a hollow bushing (8)
incorporating a stopper (9) passes through them.
5. An instant electric water heater according to previous claims, characterized in that the external vessel (1) is surrounded by an insulating layer (12).