DK2151632T3

DK2151632T3 - Organic kitchen hood and method for reducing thermal energy dispersal

Info

Publication number: DK2151632T3
Application number: DK09009595.1T
Authority: DK
Inventors: Mario Cipriani; Stefano Socci
Original assignee: Faber Spa
Priority date: 2008-08-06
Filing date: 2009-07-24
Publication date: 2016-01-11
Also published as: EP2151632A1; ITMI20081484A1; EP2151632B1

Description

DESCRIPTION

[0001] The present invention relates to an ecological kitchen hood and relative method for reducing thermal energy dispersion during its exhausting operation in accordance with the introduction to the main claims.

[0002] Traditional kitchen hoods are known to be provided with an exhaust fan and can operate in two ways, namely: exhausting, by which the air flow drawn from the environment in which the hood is located (internal environment) is totally fed through an exhaust conduit to the outside (external environment); or filtering, by which the air flow drawn from the internal environment is conveyed through a filtering conduit towards filters (for example active carbon filters) before being returned to the internal environment.

[0003] The choice of operation type is generally made by the user on installing the kitchen hood, by closing either the exhaust conduit or the filtering conduit for example by means of a baffle.

[0004] It is known e.g. from US-A-4121569 to provide a kitchen hood having an air recirculation opening and an air vent opening and further having two venting modes of operation. By providing two damper blades being operable between an open and a closed position it is possible to open the one blade and simultaneously close the other blade, and vice versa, thus either recirculating air to the kitchen or venting air outside the kitchen area, [0005] Similar hoods are also known from EP-A-0050277 and US-A-4266528.

[0006] Generally, if the user has an available outlet to the external environment, the hood is arranged for exhausting operation as this is much more efficient in eliminating odours originating from food cooking.

[0007] Although advantageous from various aspects, this solution has the drawback that, particularly during winter, the air flow W drawn from the internal environment Al by the kitchen hood C, as shown in Figure 1, has a temperature much higher than the temperature of the external environment AE. The exit of a flow W of heated air from the internal environment Al has to be compensated by the entry, for example through shutters S1 and/or appropriate aeration grids S2, of a corresponding flow F1 and F2 of air colder than the expelled air.

[0008] A further quantity of thermal energy has therefore to be used to return the temperature of the internal environment (Al) to comfortable values after the hood C has expelled to the external environment (AE) a quantity of odour-containing hot air originating from a coking hob P.

[0009] Flence although particularly effective in removing odours, a kitchen hood C operating by exhaustion results in a considerable dispersion of thermal energy.

[0010] The object of the present invention is therefore to provide an ecological kitchen hood to reduce thermal energy dispersion when operating by exhaustion.

[0011] This object is attained by a kitchen hood according to claim 1 and relative operating method according to claim 5 the inventive characteristics of which are highlighted in the accompanying claims.

[0012] The invention will be more apparent from the ensuing detailed description, provided by way of non-limiting example, of one embodiment thereof illustrated in the accompanying drawings, in which:

Figure 1, as stated, shows a schematic setting of a known kitchen hood during operation by exhausting;

Figures from 2 to 4 are schematic views of the ecological kitchen hood of the invention during its different types of operation.

[0013] With reference to Figure 2, this shows an ecological kitchen hood 1 comprising a housing 2 in which exhaust means 3, for example a fan, are fixed. The housing 2 has at least one first aperture 4 leading to the external environment AE and at least one second aperture 5 leading to the internal environment Al. According to the invention, the hood 1 is provided with closure means 6A, 6B able to assume a first position enabling the hood 1 for filtering operation. As shown in Figure 3, the closure means 6B can close the first aperture 4 to allow an air flow drawn from the internal environment Al by the fan 3 to be completely fed into the internal environment Al after passing through conventional filter means 7. The closure means 6 can also assume a second position to enable the hood 1 for exhausting operation. In particular, the closure means 6B can also leave the first aperture 4 at least partially open to enable an air flow drawn from the internal environment Al by the fan 3 to be at least partially expelled to the external environment, as shown in Figure 4.

[0014] According to the invention, when the temperature of the external environment is very low, total filtering operation Figure 3 can be enabled, whereas when particularly efficient odour elimination is required, exhausting operation Figure 2 be enabled.

[0015] Advantageously according to the invention, the closure means 6 also enable the first aperture 4 to be opened only partially such that only a portion of the indrawn flow is expelled to the external environment (AE) while a portion of the indrawn flow is returned to the internal environment (Al) after being filtered.

[0016] This second operating position can be used in particular to expel a more or less large flow quantity drawn from the internal environment (Al).

[0017] In one embodiment of the invention, the closure means 6 comprise two solenoid valves 6A and 6B arranged to tightly close the first and second aperture 4, 5 respectively, such as to set the type of operation for the hood 1.

[0018] For example, the kitchen hood 1 comprises drive means (not shown in the figures) to move said closure means 6 into the first and second operating position, and control means (not shown in the figures) connected to the drive means, to pilot the closure means 6 into one of the operating positions.

[0019] According to the invention, the kitchen hood comprises a first temperature sensor to measure the temperature of the external environment (AE), a second temperature sensor to measure the temperature of the internal environment (Al), and means for calculating the difference between the measured temperatures and comparing these temperatures (not shown in the figures). In this manner by acting on the control means on the basis of the calculated difference, one of the operating positions can be selected, as can the flow quantity to be expelled by operating to a greater or lesser extent the closure means 6 acting on the aperture 4.

[0020] Advantageously according to the invention, the filter means 7 are positioned downstream of the second aperture 5.

[0021] In this manner, the filter means 7 can be easily replaced and moreover only the recycled air flow passes through the filters, hence reducing wear and extending their life.

[0022] Flence a method is described for reducing thermal energy dispersion due to the aforedescribed exhausting operation of the kitchen hood.

[0023] In particular, if the temperature of the external environment is less than a reference temperature, the hood is enabled for filtering operation, otherwise it is enabled for exhausting operation.

[0024] For example, this external environment temperature can be measured by the user, who then manually arranges for filtering operation, or by a temperature sensor connected to control means provided in the hood to enable its filtering or exhausting operation. In this manner, each time an external environment temperature less than the reference temperature is sensed by the sensor, filtering operation is enabled for the hood.

[0025] Flence exhausting operation is normally enabled during summer while at least partially filtering operation is enabled during the colder periods of the year.

[0026] Advantageously, a further control can be provided for enabling filtering or exhausting operation of the described hood. In particular, hood filtering operation is enabled if the temperature of the external environment AE during winter is less that that of the internal environment Al by a predetermined value. In other words, this further regulating parameter enables filtering operation only when there is an internal/external temperature difference such as to introduce into the internal environment Al air which is decidedly colder than the air currently present, hence making regulation of the hood operation more accurate.

[0027] In particular, during winter, assuming the external reference temperature to be 14°C and the internal/external temperature difference to be 5°C (reference quantity), if the temperature of the external environment AE is 14°C while that of the internal environment Al is 16°C, this further control forces the hood to undergo an exhausting operation which is more effective for extracting odours.

[0028] Advantageously according to the invention, the hood 1 remains enabled for filtering operation for rates of flow drawn from the internal environment which are less than a predetermined value, whereas the hood is enabled for at least partially exhausting operation for rates of flow drawn from the internal environment which are greater than this predetermined value.

[0029] For example the hood 1 of the invention will provide filtering operation for low speeds of the exhaust means conventionally provided in kitchen hoods, and an at least partially exhausting operation for high speeds. In particular, for indrawn flow values greater than 500 m3/h, the filtering capacity of conventional carbon filters is insufficient such that, advantageously according to the invention, the air drawn from the internal environment for high flows can be conveyed at least partially towards the external environment such as to make the elimination of odours originating from food cooking more effective. Consequently, exhausting or at least partially exhausting operation is enabled only when a particularly effective odour elimination action is required.

[0030] In conclusion, the method and hood of the invention enables thermal energy dispersion due to exhausting operation of a kitchen hood to be minimized. Advantageously, when the external temperature is less than a predetermined value and the external temperature is less than the internal temperature by a predetermined delta, according to the invention, this at least partially exhausting operation is enabled only for particularly high air flows which would not allow sufficient filtration by the active carbon filters.

REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description • US412 f 569A [0004] • US4266528A [09051

Claims

Kitchen hood (1) comprising a housing (2) in which extractor means (3) are secured, the housing (2) having at least one first opening (4) leading to the external environment (AE) and at least a second opening (5) leading to the interior environment (A1), comprising valve means (6) capable of assuming a first filter operation position in which they close the first opening (4) to allow a flow of air to be drawn from the interior environment ( A1) of the extractor means (3) to be fully fed into the interior environment (A1) after passing through filter means (7), and a second extraction operation position leaving the first opening (4) at least partially open to allow a stream of air drawn from the inner environment (A1) by the exhaust means (3) to be emitted at least partially to the outer environment (AE), characterized by comprising a first temperature sensor for measuring the temperature of the outer environment (AE), another temperature sensor to measure the temperature of d an internal environment (A1), and means for calculating the difference between the measured temperatures and for comparing these temperatures to select one of the two operating positions.

Kitchen hood according to claim 1, characterized in that the closing member (6) comprises two solenoid valves (6A, 6B) arranged to close tightly the first and second apertures (4, 5) respectively.

Kitchen hood according to claim 1, characterized by extensive drive means for the closing means (6), for bringing the closing means in the first and second operating positions, and control means connected to the driving means for controlling the closing means (6) for one of the two operating positions.

Kitchen hood according to claim 1, characterized in that the filter means (7) is positioned downstream of the second opening (5).

A method of reducing thermal energy dispersion during extraction operation of a kitchen hood according to claim 1, wherein if the temperature of the external environment is less than a reference temperature, the kitchen hood is activated for filter operation, otherwise the kitchen hood is activated at least partially for extraction operation.

Process according to claim 5, characterized in that filter operation is possible if the temperature of the external environment is also less with a predetermined value than that of the internal environment.

Method according to claim 5 or 6, characterized in that the cap remains activated for filter operation at rates of flow drawn from the internal environment less than a predetermined value, whereas the cap is activated at least partially for extraction operation at rates of flow drawn from the internal environment. which is greater than this predetermined value.