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(11) | EP 2 110 610 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Kitchen hood dehumidifier device |
| (57) A kitchen hood (1) provided with a housing (2) comprising an internal heat exchanger
(3) for subtracting a first heat quantity from a gas mixture (4), at a first temperature
and with a first degree of humidity, which passes through said internal heat exchanger
(3), said internal heat exchanger (3) being connected to compression means (6) connected
in their turn to an afterheater heat exchanger (5) for transferring to a gas mixture
(7) originating from said internal heat exchanger (3) at a second temperature less
than the first temperature and with a second degree of humidity less than the first,
a second heat quantity proportional to that recovered in said internal heat exchanger
(3), said afterheater heat exchanger (5) being connected to said internal heat exchanger
(3) via a throttling device (8), wherein a vector fluid flows through said heat exchangers
(3, 5), through said throttling device (8) and through said compression means (6)
to perform a thermodynamic cycle with saturated vapour compression.
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[0001] The present invention relates to a kitchen hood with dehumidifier device in accordance with the introduction to the main claim.
[0003] In addition the reduction in the dimensions of available living accommodation is becoming increasingly greater.
[0004] There is therefore the need for a compact device which enables the air to be dehumidified but without varying the temperature within the room.
[0005] The object of the present invention is therefore to provide a kitchen hood comprising a dehumidifier device in which a fluid is made to undergo a thermodynamic cycle such that by changing its state by evaporation it absorbs heat from a hot moist gas mixture at a determined temperature, and yields heat, again mainly by changing its state by condensation at higher temperatures, to the at least partially dehumidified gas mixture such as to heat it.
[0006] This object is attained by a kitchen hood comprising a dehumidifier device with afterheating, the inventive characteristics of which are highlighted by the accompanying claims.
[0007] The invention will be more apparent from the ensuing detailed description of one embodiment thereof provided by way of non-limiting example and illustrated in the accompanying drawing, in which:
the figure shows a schematic view of a kitchen hood with a dehumidifier device comprising afterheating.
[0008] With reference to the figure, this shows a kitchen hood 1 with a housing 2 which comprises an internal heat exchanger 3 connected by a conduit 14 to compression means 6.
[0010] The compression means 6 are then connected by a further conduit 15 to the afterheater heat exchanger 5 which is connected to a throttling device 8, itself connected to the internal heat exchanger 3 such as to close the thermodynamic circuit of the invention.
[0011] Advantageously, between the internal heat exchanger 3 and the throttling device 8 stop valve means 10 are provided, preferably represented by a two-way solenoid valve, to enable or not enable a vector fluid to pass between the heat exchangers 3, 5.
[0012] A conventional vector fluid flows through the heat exchangers 3, 5, through the throttling device 8 and through the compression means 6 to perform a thermodynamic cycle with saturated vapour compression in the manner described hereinafter.
[0015] Advantageously, this internal fan is different from that conventionally provided in kitchen hoods. For example, this conventional suction fan is indicated in the figure by the reference numeral 20.
[0016] Advantageously, the afterheater heat exchanger 5 is positioned above the internal heat exchanger 3 such that the internal fan 9 can convey a gas mixture 4 drawn from the environment containing the hood 1, namely the internal environment, firstly through the internal heat exchanger 3 and then, after being processed, through the afterheater heat exchanger 5.
[0017] In this sense, a gas mixture means a mixture comprising air and possibly other gases, suspended aerosols, oily substances and water vapour.
[0018] Again advantageously, in the housing 2 first apertures 12 are provided to convey the gas mixture 4 to the internal heat exchanger 3, and second apertures 13 to expel to the internal environment the gas mixture 13a which has passed through the afterheater heat exchanger 5.
[0019] If the second suction fan 20 is located within the housing 2, the housing 2 is provided with third apertures 21 to convey a gas mixture originating from the cooking hobs to the external environment via fourth apertures 22 provided in the housing 2.
[0020] Advantageously, in the housing 2 at least one internal baffle 23 is provided to maintain the gas flow entering through the apertures 21 and leaving from the apertures 22 separate from the gas flow entering through the apertures 12 and leaving from the apertures 13.
[0021] In one embodiment of the invention, the hood 1 of the invention comprises only one fan both for expelling and for treating the gas mixtures.
[0022] For example, a double suction centrifugal fan arranged transversely to the housing 2 can be used. The rear part of the fan is used for treating the gas mixture originating from the cooking hobs while the front part is used for the gas mixture originating from the internal environment. The flow thus generated is divided into two by a separator baffle which extends into the fan volute. The first gas flow is expelled through the apertures 22 while the second gas flow is expelled through the apertures 13.
[0023] Advantageously, one or more filtration devices, not shown in the figures for simplicity, are provided in proximity to the apertures 12, 13.
[0025] In one embodiment of the invention, the internal heat exchanger 3, the compression means 6 and the internal fan 9 can be combined into a conditioning/heat pump device of known type comprising an inner unit to be positioned inside the environment to be conditioned and an outer unit 16; in particular, the internal heat exchanger 3 and the fan 9 in the inner unit of the conditioning device are as used conventionally in the inner unit of a conditioning device, while the compression means 6 are the compressor provided in the outer unit 16.
[0026] In this embodiment, the external heat exchanger 11 is connected to the internal heat exchanger 3 by a further throttling device 19. The external heat exchanger 11 is connected to the compression means 6 such that with the aid of a further external fan 17, it can operate as a conventional air conditioner or heat pump when the stop valve means 10 are closed.
[0027] Advantageously, blocking valve means 18, preferably represented by a two-way solenoid valve, are provided between the external heat exchanger 11 and the further throttling device 19.
[0028] In particular, the external heat exchanger 11, the further throttling device 19, the compression means 6 and the further external fan 17 are conventionally combined into an outer unit 16 of a conditioning device.
[0029] However in a particularly compact embodiment, there is nothing to prevent the outer unit 16 from being totally included in the housing 2 of the hood 1.
[0030] In this variant, one or more conduits must be provided to connect the external heat exchanger 11 to the external environment.
[0032] On activating the internal fan 9, the gas mixture 4 originating from the internal environment at a first temperature and with a first degree of humidity is passed through the internal heat exchanger 3. Said mixture transfers a first heat quantity to the vector fluid which flows through this internal heat exchanger 3.
[0033] In particular, by yielding heat, the gas mixture 7 cools and on reaching the dew point causes the water vapour contained in it to condense. The vector fluid heats up and evaporates to become saturated vapour.
[0034] The vector fluid in the saturated vapour state is fed to the compression device 6 for the saturated vector fluid vapours, where it is compressed and heated.
[0035] This superheated saturated vapour is then fed to the afterheater heat exchanger 5. The gas mixture 7 originating from the internal heat exchanger 3 at a second temperature less than the first and with a degree of humidity less than the first degree of humidity is forced through the afterheater heat exchanger 5 where it acquires a heat quantity from the vector fluid. By means of this process the temperature of the gas flow 13a leaving the hood 1 returns to values close to that of the gas flow 4 from the internal environment. The vector fluid in the superheated saturated vapour state, after being cooled and condensed, is fed to the throttling device 8 to undergo temperature and pressure reduction before being returned to the internal heat exchanger 3 to recommence the thermodynamic cycle.
[0036] The steam condensate from the gas mixture 4 is collected in collection means provided below the heat exchanger 3.
[0037] If the hood of the invention also comprises the throttling device 19 and the external heat exchanger 11, in this method of operation the blocking valve means 18 are closed, while the stop valve means 10 are open.
[0038] According to this method, the hood 1 of the invention can reuse the heat extracted from the gas mixture 4 present in the internal environment during dehumidification, to then heat it before its entry into the environment, and hence to implement a process of just dehumidification without changing the ambient temperature.
[0039] This internal heat transfer is effected by a vector fluid which acts as a thermal vector within the thermodynamic saturated vapour cycle, also known as a heat pump.
[0040] This avoids the use of energy for afterheating the gas mixture 7 while simultaneously preventing heat dispersion during condensation, in contrast to what happens in conventional dehumidifier devices integrated into common atmospheric air conditioners in which the heat quantity absorbed during air dehumidification is dispersed into the external environment to hence constitute an energy loss from the system. It also prevents the dehumidified air at a lower temperature than ambient from being fed into the environment, so lowering its temperature.
[0041] Finally as can be deduced from the aforegoing, by closing the stop valve means 10 and opening the blocking valve means 18, the hood 1 of the invention can operate as a conventional conditioning device or heat pump, by using the internal heat exchanger 3 and the fan 9 for cooling and dehumidifying the air in summer or heating it in winter, while the further throttling device 19, the compression means 6, a further external fan 17 and the external heat exchanger 11 act as a conventional outer unit 16 of the conditioning device or heat pump.
[0042] Advantageously according to the invention, the valve means are connected to a control unit which enables their opening or closure on the basis of the operating modality required by the user.
[0043] Moreover by providing external sensors which measure the parameters of the internal environment, those of the external environment and the operating conditions of the hood 1 of the invention, all the functions necessary for controlling the temperature and the relative humidity of the gas flow expelled by the hood 1 can be automatically coordinated.
1. A kitchen hood (1) provided with a housing (2) comprising an internal heat exchanger
(3) for subtracting a first heat quantity from a gas mixture (4), at a first temperature
and with a first degree of humidity, which passes through said internal heat exchanger
(3), said internal heat exchanger (3) being connected to compression means (6) connected
in their turn to an afterheater heat exchanger (5) for transferring to a gas mixture
(7) originating from said internal heat exchanger (3) at a second temperature less
than the first temperature and with a second degree of humidity less than the first,
a second heat quantity proportional to that recovered in said internal heat exchanger
(3), said afterheater heat exchanger (5) being connected to said internal heat exchanger
(3) via a throttling device (8), wherein a vector fluid flows through said heat exchangers
(3, 5), through said throttling device (8) and through said compression means (6)
to form a thermodynamic cycle with saturated vapour compression.
2. A kitchen hood (1) as claimed in claim 1, wherein said compression means (6) are located
outside said hood.
3. A kitchen hood (1) as claimed in claim 1, wherein said afterheater heat exchanger
(5) is positioned in proximity to said internal heat exchanger (3).
4. A kitchen hood (1) as claimed in claim 1, comprising a fan (9) positioned in proximity
to said afterheater heat exchanger (5).
5. A kitchen hood (1) as claimed in claim 1, wherein said fan (9), one of said heat exchangers
(3, 5) and said compression means (6) are those conventionally provided in a conditioning
device/heat pump.
6. A kitchen hood (1) as claimed in claim 1, comprising stop valve means (10) positioned
between said internal heat exchanger (3) and said afterheater heat exchanger (5).
7. A kitchen hood (1) as claimed in claim 6, wherein according to a further method of
operation, an external heat exchanger (11) is provided connecting a further throttling
device (19) to the internal heat exchanger (3), said external heat exchanger (11)
being connected to compression means (6) in such a manner as to operate as a conventional
conditioning device or heat pump when said second stop valve means (10) are closed.
8. A kitchen hood (1) as claimed in claim 1, wherein said hood (1) comprises first apertures
(12) to convey said gas mixture (4) to said internal heat exchanger (3), and second
apertures (13) to expel to the internal environment a gas mixture (13a) which has
passed through said afterheater heat exchanger (5), said gas mixture (13a) having
a temperature substantially equal to the first temperature.