FIELD OF THE INVENTION

The present invention relates to kitchen chimneys. Particularly, the present invention relates to an energy efficient kitchen chimney which is capable of expelling both smoky/hot gas of oven and spicy/oily vapour of foods through separate conduits/pipes, by utilizing the temperature difference therebetween. The proposed kitchen chimney can be operated with or without external energy (i.e. electricity), and used in both non-electrical and electrical ovens.

BACKGROUND OF THE INVENTION
Kitchen chimney is a day-to-day useful appliance that sucks hot gas, fume, smoke, vapour, odour, and oil produced during cooking, and expels them to outside, so that the kitchen remains clean and non-greasy and the users can comfortably and hygienically work inside the kitchen/room. There are various types of kitchen chimneys available for domestic/household purpose in the present market. The most popular models are Wall-Mounted Chimney (installed against the wall), Island Chimney (installed in the middle of the kitchen ceiling), Built-In Chimney (fitted inside the wooden furniture in the kitchen), Corner Chimney (fixed at the corner of the kitchen), which particularly involve complex/expensive structures and are operated by consuming substantial amount of external energy (i.e. electric power).
Moreover, the conventional (electrical) chimneys used in kitchens are not energy efficient in expelling the smoky/hot gas of oven or the spicy/oily vapour of foods while cooking. Usually, in those structures a common vertical pipe is used to expel the mixed hot exhaust gases/vapours.
A reference may be made to US4043313A that discloses a chimney specifically in the form of at least one vertically oriented multiple tube shell type heat exchanger in place of the conventional fireplace wherein the flue gases pass inside the tubes and the room air is heated inside the shell.
Another reference may be made to US20100186731A1 a furnace or heat collection device to be installed in or above the firebox of a residential fireplace, chimney, commercial smokestack, etc.
A further reference may be made to CN201237259Y that discloses a domestic smokeless warming furnace. The furnace adopts the principle of combustion in both the front and the rear sides and comprises two furnace tanks and two grate bars, and a curved fireproof arch is arranged inside a primary combustion chamber. Coal bricks are fed into the primary combustion chamber for combustion from a coal feeding and oxygen adjusting door, and the combusting flame and non-burnt out burning coal bricks continue combusting in a secondary combustion chamber. A mixed flame obtained after combusting in the secondary combustion chamber is introduced into a smoke abatement and dust fall settlement chamber from flues on the two sides in the furnace, directly rushes to the bottom of a baking chamber arranged at the upper end of the furnace body, and is discharged into the air from a smoke outlet port of the furnace body through vertical and transverse heat radiating chimneys additionally arranged indoor and outdoor.
However, all existing kitchen chimneys/furnaces have limitations of high energy consumption. In all existing/known techniques the oven smoky/hot gases and the food spicy/oily vapours are mixed together in a common exhaust pipe and pumped for releasing into the atmosphere. Particularly, the suction motors/blowers used in electrical kitchen chimney/furnace consume substantial amount of external energy/electricity due to continuous use in expelling the total amount of mixed gases (i.e. substantially higher than individual gases). In order to overcome these deficiencies the present invention proposes an energy efficient kitchen chimney, which can be operated with or without any motor/blower and electronic controller depending type of oven/fuel. Further, the proposed kitchen chimney can be used in both non-electrical and electrical ovens. Moreover, it is desired to develop a smart system and method for expelling the kitchen exhaust gases/fumes/vapour without any external energy consummation or at a minimal external energy consummation cost, which overcomes the deficiencies of such techniques/methodologies with added advantage of easier maintenance and high reliability.

OBJECT OF THE INVENTION
It is an object of the present invention to provide an energy efficient kitchen chimney capable of being operated with or without any motor/blower and controller/sensor.

It is another object of the present invention to provide an energy efficient kitchen chimney capable of being used in both electrical and non-electrical ovens with improved functioning.

It is a further object of the present invention to provide a kitchen chimney that is easy for maintenance/cleaning, cost effective, and reliable and fulfils all safety parameters.

SUMMARY OF THE INVENTION
In one aspect, the present invention provides an energy efficient kitchen chimney. The chimney comprises: a hopper to be mounted above an oven housed in an oven chamber; a first exhaust pipe connected to an outlet of the oven chamber and vertically mounted against a wall support for releasing smoky/hot gas emitted therefrom; and a second exhaust pipe connected at top of the hopper and extended into an upper vertical portion of the first exhaust pipe for releasing spicy/oily vapour emitted from foods to be cooked. Particularly, the first exhaust pipe is made up of heat insulating material capable of preventing heat loss of the smoky/hot gas before releasing into atmosphere, whereas the second exhaust pipe is a metal pipe having a slanting part coated with insulating material, and an upper vertical part coaxially fitted inside the upper vertical portion of the first exhaust pipe. Further, the slanting part is preferably aligned collinearly with an inclined front surface of the hopper and extended towards the upper vertical part crossing the wall at preferably less than 45 degree angle with respect to a vertical plane of the wall. The kitchen chimney further comprises a suction motor mounted with a non-magnetic and heat insulating vertical pipe between the hopper top and the slanting part lower end of the second exhaust pipe. Furthermore, the chimney comprises an electronic controller coupled with thermistors/sensors for automatic operation of the suction motor.

Other aspects, advantages, and salient features of the present invention will become apparent to those skilled in the art from the following detailed description, which delineate the present invention in different embodiments.

BRIEF DESCRIPTION OF DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying figures.

Fig. 1: Fig. 1(a) and Fig. 1(b) are front view and side view respectively, illustrating an energy efficient kitchen chimney with suction motor and electronic controller/sensor, in accordance with an embodiment of the present invention.

Fig. 2: Fig. 2(a) and Fig. 2(b) are front view and side view respectively, an energy efficient kitchen chimney without suction motor and electronic controller/sensor, in accordance with an embodiment of the present invention.

Fig. 3 illustrates a typical suction motor structure used in the proposed energy efficient kitchen chimney, in accordance with an embodiment of the present invention.

List of reference numerals

1 Oven chamber
2 Chimney Hopper
3 Slanting part of second exhaust pipe
4 Upper vertical part of second exhaust pipe
5 Hopper front surface slope
6 First exhaust pipe (oven exhaust pipe)
7 Flattened projections (heat conducting/exchanging members)
8 Lower vertical pipe for holding suction motor
9 Suction motor
10 Fan/rotor (single slim blade)
11 Support rings for fan/rotor
12 Oven Thermistor
13 Hopper Thermistor
14 Support wall
15 Second exhaust pipe (Hopper exhaust pipe)

DETAILED DESCRIPTION OF THE INVENTION
Various embodiments described herein are intended only for illustrative purposes and subject to many variations. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but are intended to cover the application or implementation without departing from the scope of the present invention. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

The use of terms “including,” “comprising,” or “having” and variations thereof herein are meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Further, the terms, “an” and “a” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items.

According to an embodiment of the present invention, as shown in Fig. 1-2, the energy efficient kitchen chimney comprises: a hopper (2) to be mounted above an oven housed in an oven chamber (1); a first exhaust pipe (6) connected to an outlet of the oven chamber (1) and vertically mounted against a wall support (14) for releasing smoky/hot gas/fume emitted therefrom; and a second exhaust pipe (15) connected at top of the hopper (2) and extended into an upper vertical portion of the first exhaust pipe (6) for releasing spicy/oily vapour emitted from foods to be cooked. In a kitchen, at the time cooking two types of gases/vapours are released; one from the oven i.e. the smoky/hot gas/fume, and other from the cooked food i.e. the spicy/oily vapour. Usually, the smoky/hot gas/fume of the oven has a higher temperature than the spicy/oily vapour of the cooked foods. Particularly, the smoky/hot gas/fume of the oven is not mixed with the spicy/oily vapour of the cooked foods before being released into the atmosphere. The present invention employs the principle of heat transfer/conduction due to such temperature difference for expelling both gases/vapours efficiently through the undermentioned exhaust pipe assembly/arrangement.

According to an embodiment of the present invention, the first exhaust pipe (6) is made up of heat insulating material capable of preventing heat loss of the smoky/hot gas before releasing into atmosphere. The second exhaust pipe (15) is a metal pipe having a slanting part (3) coated with insulating material, and an upper vertical part (4) coaxially fitted inside the upper vertical portion of the first exhaust pipe (6). The slanting part (3) is collinearly aligned with an inclined front surface (5) of the hopper (2) and extended towards the upper vertical part (4) crossing the wall (14) preferably at less than 45 degree angle with respect to a vertical plane of the wall (14). These structures make the present invention advantageous in terms of preventing heat loss of the gases/vapours inside both exhaust pipes before being expelled; thus the higher temperature of the smoky/hot gas/fume present inside the first exhaust pipe (6) [i.e. outside the upper vertical part (4) of the second exhaust pipe (15)] causes upward movement of the spicy/oily vapour present inside the second exhaust pipe (15). In this way both gases/vapours are expelled into the atmosphere (i.e. outside kitchen) using the first and second exhaust pipes without any external energy/electricity and utilizing minimum space against the wall support.

According to an embodiment of the present invention, the upper vertical part (4) of the second exhaust pipe (15) is externally provided with a plurality of heat conducting/exchanging flattened projections (7) inside the upper vertical portion of the first exhaust pipe (6). These flattened projections act as heat conductor/exchanger between the smoky/hot gas/fume and the spicy/oily vapour.

According to an embodiment of the present invention, as shown in Fig. 3, the chimney comprises a suction motor (9) mounted with a non-magnetic and heat insulating vertical pipe (8) between the hopper top and the slanting part lower end of the second exhaust pipe (15). Particularly, the suction motor (9) is smartly designed/configured to improve working efficiency of the chimney at very minimum external energy/electricity consumption cost. It is surprisingly found that this suction motor (9) saves more 75% of the external energy/electricity as compared with the motor/blower used in the existing/known chimneys.

In a preferred embodiment, the suction motor (9) comprises a rotor/fan (10) made up of magnetic material being fitted inside the vertical pipe (8) using a pair non-magnetic support rings (11) or hinges/bearings fitted with the vertical pipe (8), and a stator similar to a BLDC (brushless direct current) type motor stator mounted outside the vertical pipe (8). The rotor (10) is a twisted narrow/slim single blade fan adapted to move the spicy/oily vapours (emitted from the cooked food) upward with the given direction of rotation. The narrow fan blade causes minimum hindrances to the spicy/oily vapour of food while the motor (9) is stopped in non-electrical mode of functioning. The fan (10) is preferably placed between two support rings (11) fixed inside the vertical pipe (8). Instead of the supporting rings (11), the fan (10) can be supported using a hinge or bearings with a fixed support fitted in the vertical pipe (8). The vertical pipe (8), the supporting rings (11) and hinge/bearing support are essentially made of non-magnetic materials and preferably insulating materials also.

According to an embodiment of the present invention, the chimney comprises an electronic controller coupled with an oven thermistor (12) attached to the oven chamber (1), and a hopper thermistor (13) attached inside the hopper top. Such configuration of the heat/temperature sensors/thermistors (12, 13) with the controller becomes advantageous in terms of enabling automatic operation of the suction motor (9) by sensing the temperature difference therein.

In a preferred embodiment, the electronic controller is configured to turn on the suction motor (9), while the oven thermistor (12) detects an ambient temperature or absence of the smoky/hot gas released from the oven, and the hopper thermistor (13) detects a temperature higher than the ambient temperature or presence of the spicy/oily vapour released from the cooked food under the hopper (2).

In a preferred embodiment, the electronic controller is configured to turn off the suction motor (9) while the oven thermistor (12) detects a temperature higher than the ambient temperature or presence of the smoky/hot gas released from the oven.

More specifically, the suction motor (9) is operated using the same principle of BLDC motor, with high speed suitably for the narrow fan blade. The motor (9) requires very less energy as it is used for suctioning only spicy/oily vapour of cooked foods, unlike the conventional chimneys in which the smoky/hot gas of oven is mixed with the spicy/oily vapour of food and the total mixed exhaust gas (i.e. substantial higher amount) is needed to be suctioned using powerful motors, thus consuming significant amount of energy. However, in the present invention a maximum amount of exhaust gas i.e. the smoky/hot gas of oven, exits naturally requiring no extra forces of suctioning; thus the motor (9) remains turned off as long as the presence of smoky/hot gas of the oven is detected. The motor (9) can be operated manually or automatically using the electronic controller with sensing the spicy/oily vapour at the hopper top and no smoky/hot gas in the oven exhaust outlet through the temperature sensors/thermistors (12, 13).

In a preferred embodiment, the chimney is compatible with electrical and non-electrical ovens and capable of functioning with or without the motor (9) operated by external energy/electricity.

In a preferred embodiment, the chimney is capable of being manually operated without the electronic controller/sensors by using an ON/OFF switch coupled with the suction motor (9).

According to an embodiment of the present invention, in case of non-electric oven, the oven is fitted within the oven chamber (1) so as to keep cooking utensils in contact with the oven surface in a way to avoid leakage of the smoky/hot gas of the oven and mixing with the spicy/oily vapour of the cooked food. Such arrangement/fitting prevents mixing of the smoky/hot gas of oven with spicy/oily vapour of foods; and at the same time the heat produced by oven is optimally utilized for cooking purpose and chimney functioning.

The proposed energy efficient kitchen chimney provides following advantages including but not limited to:
• The kitchen chimney has simple structure, high practicability, and easy installation.
• The kitchen chimney can be operated with or without the motor/blower that consumes a negligible amount of electricity; thus, energy efficient.
• The construction/manufacturing of the kitchen chimney is cost effective and compatible with both non-electrical (conventional/traditional) and electrical (modern) ovens.

The foregoing descriptions of exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiment was chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable the persons skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions, substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but is intended to cover the application or implementation without departing from the scope of the claims of the present invention.

I claim:

1. An energy efficient kitchen chimney, comprising:
- a hopper (2) to be mounted above an oven chamber (1);
- a first exhaust pipe (6) connected to an outlet of the oven chamber (1) and vertically mounted against a wall support (14) for releasing smoky/hot gas emitted therefrom; and
- a second exhaust pipe (15) connected at top of the hopper (2) and extended into an upper vertical portion of the first exhaust pipe (6) for releasing spicy/oily vapour emitted from foods to be cooked;
wherein the first exhaust pipe (6) is made up of heat insulating material capable of preventing heat loss of the smoky/hot gas before releasing into atmosphere,
wherein the second exhaust pipe (15) is a metal pipe having a slanting part (3) coated with insulating material, and an upper vertical part (4) coaxially fitted inside the upper vertical portion of the first exhaust pipe (6),
wherein the slanting part (3) is collinearly aligned with an inclined front surface (5) of the hopper (2) and extended towards the upper vertical part (4) crossing the wall (14) at less than 45 degree angle with respect to a vertical plane of the wall (14).

2. The kitchen chimney as claimed in claim 1, wherein the upper vertical part (4) of the second exhaust pipe (15) is externally provided with a plurality of heat conducting/exchanging flattened projections (7) inside the upper vertical portion of the first exhaust pipe (6),
.
3. The kitchen chimney as claimed in claim 1, wherein the chimney comprises a suction motor (9) mounted with a non-magnetic and heat insulating vertical pipe (8) between the hopper top and the slanting part lower end of the second exhaust pipe (15).

4. The kitchen chimney as claimed in claim 3, wherein the suction motor (9) comprises a rotor/fan (10) made up of magnetic materials, being fitted inside the vertical pipe (8) using a pair non-magnetic support rings (11) or hinges/bearings fitted with the vertical pipe (8), and a stator similar to a BLDC (brushless direct current) type motor stator mounted outside the vertical pipe (8).

5. The kitchen chimney as claimed in claim 3, wherein the chimney comprises an electronic controller coupled with an oven thermistor (12) attached to the oven chamber (1), and a hopper thermistor (13) attached inside the hopper top.

6. The kitchen chimney as claimed in claim 5, wherein the electronic controller is configured to turn on the suction motor (9), while the oven thermistor (12) detects an ambient temperature or absence of the smoky/hot gas released from the oven, and the hopper thermistor (13) detects a temperature higher than the ambient temperature or presence of the spicy/oily vapour released from the cooked food under the hopper (2).

7. The kitchen chimney as claimed in claim 5, wherein the electronic controller is configured to turn off the suction motor (9) while the oven thermistor (12) detects a temperature higher than the ambient temperature or presence of the smoky/hot gas released from the oven.

8. The kitchen chimney as claimed in claim 5, wherein the chimney is compatible with electrical and non-electrical ovens, and capable of functioning with or without the motor (9) operated by external energy/electricity.

9. The kitchen chimney as claimed in claim 5, wherein the chimney is capable of being manually operated without the electronic controller by using an ON/OFF switch coupled with the suction motor (9).

10. The kitchen chimney as claimed in claim 1, wherein in case of the non-electrical ovens, the oven is fitted within the oven chamber (1) so as to keep cooking utensils in contact with the oven surface in a way to avoid leakage of the smoky/hot gas of the oven and mixing with the spicy/oily vapour of the cooked food.