EP2502682A2

EP2502682A2 - Exhaust device having deflection plates

Info

Publication number: EP2502682A2
Application number: EP11171303A
Authority: EP
Inventors: Rong Fung Huang
Original assignee: National Taiwan University of Science and Technology NTUST
Current assignee: National Taiwan University of Science and Technology NTUST
Priority date: 2011-03-22
Filing date: 2011-06-24
Publication date: 2012-09-26
Also published as: JP2012198008A; EP2502682A3; TW201239286A; JP5362783B2; TWI426220B

Abstract

An exhaust device (1) having deflection plates (3,4) comprises a cabinet (2) that is provided with a space (27) therein. An opening is formed in front of the cabinet. The air-extraction hood (21) located at the top of the cabinet is provided at the bottom thereof with an elongate air-extraction slot (212) facing downwards and parallel to a rear plate (26). A left deflection plate (3) is vertically located in the space in a manner of being relatively oblique to a left lateral plate (23) while a right deflection plate (4) is vertically located in the space in a manner of being relatively oblique to a right lateral plate (24). Thereby, the air drawn towards the elongate air-extraction slot can flow into the cabinet via the left and the right deflection plates so as to prevent the leakage of pollutants from the opening in front of the cabinet.

Description

Technical Field

The present invention relates to an exhaust device having deflection plates, and more particularly, to an exhaust device that has deflection plates used for guiding the airflow in the cabinet so as to prevent the leakage of pollutants and is suitable for the cabinets in factories and laboratories and the exhaust cabinets in commercial kitchens.

Background

For performing the function of a conventional exhaust cabinet, a shelter plate with an opening is provided on the upper end of a cabinet, and a flow-guide plate is vertically placed in the rear of the cabinet, where the flow-guide plate is provided with a specially designed opening. Through the opening of the shelter plate and the opening of the flow-guide plate in the rear of the cabinet, harmful gas can be drawn out by using an air-extraction machine and ducts. When the exhaust cabinet is used, the air-extraction machine should be operated correspondingly in order to continue air extraction. During this moment, the door of the cabinet should not be closed completely or an opening should be provided at the doorsill in advance in order to prevent burning of a motor resulting from failing to supply air. Besides, when in use, it is usually necessary to open the door of the cabinet to an approximate height to facilitate operators stretching their hands into the cabinet for experimental operations. However, when the door of the conventional exhaust cabinet is open, based on the principles of Aerodynamics, harmful gas within the cabinet may escape easily around the peripheries of the door. Moreover, the leakage may be even severer when operators are opening or closing the door, or stand in front of the open cabinet for experimental operations, or when there are ambient drafts or there are people walking by. The main reason of the leakage is that vortex and turbulence are easily formed around the peripheries of the cabinet door and around operators' chests. The vortex and turbulence may result in the mass and momentum exchange between the inside and the outside of the cabinet. Therefore, the leakage of the pollutants in the cabinet is scarcely avoidable. Unfortunately, there is nearly no conventional exhaust cabinet can be used without opening and closing its door. In other words, operators can operate their experiments only when the cabinet is open. Besides, the exhaust cabinet is scarcely placed in the environment where there is no ambient air turbulence or there are no people walking by. As a result, in the laboratories, factories, or buildings using the conventional exhaust cabinets, people usually smell the sour odor emitted from chemicals because pollutants continue leaking from the cabinets. Operators and people working thereby may get used to the odor and long-term chemical pollution occurs.
In order to solve the leakage problem resulting from using above conventional exhaust cabinet, an oblique dual air curtain exhaust cabinet has been developed as shown in Fig. 13 and 14. An opening is respectively provided in front of and in back of the cabinet "a". Besides, an air blow part (b, b1) is respectively provided in front of and in back of a bottom plate of the cabinet "a". Through the two air blow parts (b, b1), air jets are blown upwards in oblique directions opposite to each other. An air-extraction hood "c" is provided in the space above the bottom plate. The air-extraction hood "c" is provided with an air-extraction part "c1". The air-extraction part "c1" is parallel to the two air blow parts (b, b1). Besides, the air-extraction part "c1" is located just above and between the two air blow parts (b, b1). Thereby, when the air-extraction part "c1" draws in air while the air blow parts (b, b1) blow air, two oblique air curtains (d, d1) flowing from bottom towards top can be formed in order to exhaust the pollutants confined between the two oblique air curtains.
According to the structure of the dual air curtain exhaust cabinet, the front and the back sides of the cabinet are respectively formed an open space for operators to perform operations, whereas the left and the right sides thereof are enclosed in order to confine harmful gas therein. In practical use, the two ends of each elongate air blow part (b, b1) should be spaced from the left and right lateral plates (e, e1) in a certain distance (f, f1) so as to supply fresh air in. However, because the left and the right lateral plates (e, e1) are completely enclosed ones, experimental results show that unsteady vortex will appear in the cabinet after the air flows in respectively through the gaps between the two ends of the air blow parts (b, b1) and the left and right lateral plates (e, e1). Consequently, airflow will partially flow out through the two gaps so as to result in the leakage of harmful gas.
In order to overcome above shortcomings, inventor had the motive to study and develop the present invention. After hard research and development, the inventor provides an exhaust device having deflection plates, which is capable of preventing effectively the leakage of pollutants so as to ensure the safety in use.

Summary of the disclosure

An object of the present invention is to provide an exhaust device having deflection plates, where an elongate air-extraction slot is provided on the bottom of the air-extraction hood, and a left and a right deflection plates are provided in the space beneath the cabinet so as to exhaust high-temperature pollutants or soot effectively and prevent the leakage of the pollutants or soot.
Another object of the present invention is to provide an exhaust device having deflection plates, where an elongate air blow part is provided in front of the bottom plate of the cabinet, and a left and right deflection plates are respectively provided in air-supply spaces located at the left and right sides of the elongate air blow slot, so as to confine the airflow inside the cabinet and prevent the leakage of pollutants.
Another object of the present invention is to provide an exhaust device having deflection plates, where a guiding plate is respectively provided at the front ends of the left and right lateral plates, and a guiding part is provided on the bottom of the front plate, so as to let airflow smoothly flow into the cabinet and reduce the size of the backflow area in order to decrease the possibility of pollutants' leakage.
In order to achieve above objects, the present invention provides an exhaust device having deflection plates, comprising a cabinet, a left deflection plate, and a right deflection plate. The cabinet includes an air-extraction hood, a bottom plate, a left lateral plate, a right lateral plate, and a rear plate, all of which define a space. An opening is provided in front of the cabinet. An air-extraction part is provided at the bottom of the air-extraction hood. The air-extraction part has an elongate air-extraction slot facing downwards and the elongate air-extraction slot is parallel to the rear plate. The air-extraction part is connected with an air-extraction machine for drawing air upwards. The left deflection plate is vertically located in the space in a manner of being relatively oblique to the left lateral plate, so as to form a first included angle between the left deflection plate and the left lateral plate. The right deflection plate is symmetrical to the left deflection plate and is vertically located in the space in a manner of being relatively oblique to the right lateral plate, so as to form a second included angle between the right deflection plate and the right lateral plate. Thereby, it is able to guide the airflow in the cabinet and prevent its leakage.
In practice, the front end of the left deflection plate is in a position closely against the right lateral surface of the left lateral plate. The front end of the right deflection plate is in a position closely against the left lateral surface of the right lateral plate. Besides, the first and the second included angles face towards the rear plate.
In practice, a curved first guiding part is provided at the bottom of the front end of the air-extraction hood, while a curved second guiding part is provided at the top of the front end of the bottom plate. Moreover, a curved first guiding plate is provided at the front end of the left lateral plate of the cabinet, while a curved second guiding plate is provided at the front end of the right lateral plate of the cabinet for guiding airflow flowing into the space.
In practice, an elongate air blow part is provided in front of the bottom plate. The elongate air blow part has an elongate air blow slot with an opening facing vertically upward or obliquely upwards for blowing air jets vertically and upwards or in a direction towards the rear plate of the cabinet. A first air-supply space is formed between the left end of the elongate air blow part and the left lateral plate. A second air-supply space is formed between the right end of the elongate air blow part and the right lateral plate. The elongate air blow slot is parallel to the elongate air-extraction slot so as to form a nearly two-dimensional oblique air curtain between the elongate air-extraction part and the elongate air blow part during the air-extraction machine is in operation.
In practice, the exhaust device having deflection plates according to the present invention alternatively comprises a cabinet, a front and a rear left deflection plates, and a front and a rear right deflection plates. The cabinet includes an air-extraction hood, a bottom plate, a left lateral plate, and a right lateral plate, all of which define a space. An opening is respectively provided in front of and in back of the cabinet. An air-extraction part is provided at the bottom of the air-extraction hood. The air-extraction part has an elongate air-extraction slot facing downwards and the elongate air-extraction slot is perpendicular to the left and right lateral plates. The air-extraction part is connected with an air-extraction machine for drawing air upwards. The front and rear left deflection plates are respectively vertically located in the space in a manner of being relatively oblique to the left lateral plate, so as to form a first included angle between the front and the rear left deflection plates and the left lateral plate. The front right deflection plate is symmetrical to the front left deflection plate, while the rear right deflection plate is symmetrical to the rear left deflection plate. The front and the rear right deflection plates are respectively vertically located in the space in a manner of being relatively oblique to the right lateral plate, so as to form a second included angle between the front and the rear right deflection plates and the right lateral plate.
The following detailed description, given by way of examples or embodiments, will best be understood in conjunction with the accompanying drawings.

Brief Description of the Drawings

Fig.1 shows a front side cross-sectional view of a first embodiment of the present invention.
Fig.2 shows a lateral side cross-sectional view of the first embodiment of the present invention.
Fig.3 shows a topside cross-sectional view of the first embodiment of the present invention.
Figs.3A and 3B show another embodiment of the air-extraction hood of the present invention.
Figs. 4 and 5 show the use of the first embodiment of the present invention.
Fig.6 shows a lateral side cross-sectional view of a second embodiment of the present invention.
Fig.6A shows a lateral side cross-sectional view of the present invention where a movable cabinet door is installed.
Fig.7 shows a topside cross-sectional view of the second embodiment of the present invention.
Figs.8-10 show the use of the second embodiment of the present invention.
Fig.11 shows the use of a third embodiment of the present invention.
Fig.11A shows a lateral side cross-sectional view of the present invention where an air blow device is provided on the bottom of the movable cabinet door.
Fig.12 shows a topside cross-sectional view of a fourth embodiment of the present invention.
Fig.13 shows a front side cross-sectional view of a conventional air-curtain type exhaust cabinet.
Fig.14 shows a lateral side cross-sectional view of the conventional air-curtain type exhaust cabinet.

Detailed Description

Please refer to Figs.1-3 showing a first embodiment of an exhaust device having deflection plates 1, which comprises a cabinet 2, a left deflection plate 3, and a right deflection plate 4.
The cabinet 2 is in substantially rectangular or square shape. The lower part of the cabinet 2 is provided with a storage cabinet 29 for storage purpose. The storage cabinet 29 has legs and is able to support the cabinet 2. The cabinet 2 has an air-extraction hood 21, a bottom plate 22, a left lateral plate 23, a right lateral plate 24, and a rear plate 26. After being assembled together, above components define a space 27 within the cabinet 2. An opening 251 is provided below the front end of the air-extraction hood 21. Besides, a curved first guiding part 252 is provided at the bottom of the front end of the air-extraction hood 21, and a curved second guiding part 226 is provided at the top of the front end of the bottom plate 22. The front ends of the left lateral plate 23 and the right lateral plate 24 in the cabinet 2 are respectively provided with a curved first guiding plate 231 and a curved second guiding plate 241. Thereby, it is able to reduce the degree of turbulence and agitation produced when air is drawn into the opening 251. In implementation, the first guiding part 252, the second guiding part 226, the first guiding plate 231, and the second guiding plate 241 can be in a shape of a quarter arc of a circle or of a curved surface having a large curvature radius, both of which are capable of producing airflow-guiding effect.
The air-extraction hood 21 is provided with an air-extraction part 211 on its bottom. The air-extraction part 211 has an elongate air-extraction slot 212 facing downwards. The elongate air-extraction slot 212 is substantially rectangular. The elongate air-extraction slot 212 is lengthwise parallel to the rear plate 26. A plurality of air exhaust outlets 213 is provided on the top of the air-extraction hood 21. Each air exhaust outlet 213 is connected to an air collector 214 and the air collector 214 is connected with an air-extraction device 215. Thereby, when the air-extraction device 215 is in operation, the elongate air-extraction part 212 is capable of drawing in air and guiding the air in the cabinet 2 to flow upwards. In implementation, the air-extraction device 215 can be a drawing fan, air blower, or other fluid mechanisms capable of extracting air. Moreover, the bottom 216 of the air-extraction hood 21 is provided with a liquid barrier frame 217. The liquid barrier frame 217 protrudes upwards from the surface of the bottom plate 216 and surrounds the peripheries of the elongate air-extraction slot 212. A liquid collector 218 is provided below the rear end of the bottom plate 216 of the air-extraction hood 21. Alternatively, the liquid collector 218 also can be provided below the front end or the lateral end of the bottom plate 216.
In implementation, the air-extraction hood 21 also can be a substantially L-shape casing. As shown in Fig.3A, the elongate air-extraction slot 212 faces downwards and obliquely at an angle. Alternatively, as shown in Fig.3B, the elongate air-extraction slot 212 faces in a direction away from the rear plate 26.
The left and right deflection plates 3, 4 are respectively a rectangular upright plate. The left deflection plate 3 is vertically located in the space 27 in a manner of being relatively oblique to the left lateral plate 23. Besides, the front end of the left deflection plate 3 is in a position closely against the right lateral surface of the left lateral plate 23, so as to form a first included angle θ1 between the left deflection plate 3 and the left lateral plate 23. The first included angle θ1 faces towards the rear plate 26. The right deflection plate 4 is symmetrical to the left deflection plate 3. Besides, the right deflection plate 4 is vertically located in the space 27 in a manner of being relatively oblique to the right lateral plate 24. Besides, the front end of the right deflection plate 4 is in a position closely against the left lateral surface of the right lateral plate 24, so as to form a second included angle θ2 between the right deflection plate 4 and the right lateral plate 24. The second included angle θ2 also faces towards the rear plate 26.
As shown in Figs.4 and 5, when any item or facility on a countertop is of a heating apparatus 9 that will produce high-temperature pollutants or soot (such as a heating furnace or a heating plate), the high-temperature pollutants or soot will move upwards due to buoyancy effect inherent of high-temperature gas. When the air-extraction device 215 is in operation, the high-temperature pollutants or soot can be drawn upwards into the air-extraction slot 212. Consequently, external air in front of the cabinet 2 can be drawn into the cabinet space 7 via the opening 251. The airflow can be guided by the left deflection plate 3 and the right deflection plate 4, so as to form closely-juxtaposed steady vortex pairs (as shown in Fig.4) that is capable of carrying the high-temperature pollutants or soot steadily and upwards and exhausting it via the air-extraction slot 212. When airflow flows along the right lateral surface of the left lateral plate 23 and the left lateral surface of the right lateral plate 24 of the cabinet 2, the airflow flowing into the cabinet 2 will not flow back to the original entrance opening 251 by means of the hindrance and the guidance of the left and right reflection plates 3, 4. As a result, it is able to prevent the leakage of high-temperature pollutants or soot.
Please refer to Figs.6 and 7 showing a second embodiment of an exhaust device 1 having deflection plates. This embodiment differs from the first embodiment in following aspects: where a front plate 25 is further provided below the front end of the cabinet 2; the opening 251 is provided below the front plate 25; and the first guiding part 252 is a semicircular bar that is provided at the internal side of the bottom of the front plate 25. Alternatively, in implementation, as shown in Fig.6A, the front plate 25 has a lateral part overlapped with a movable cabinet door 255; the first guiding part 252 is provided at the internal side of the bottom of the movable cabinet door 255; and the movable cabinet door 255 is slidable upwards and downwards relative to the front plate 25 in order to control the opening degree of the movable cabinet door 255. In addition, an elongate air blow part 221 is provided at the front side of the bottom plate 22 of the cabinet 2. A first air-supply space 222 is formed between the left end of the elongate air blow part 221 and the left lateral plate 23. A second air-supply space 223 is formed between the right end of the elongate air blow part 221 and the right lateral plate 24. Besides, the elongate air blow part 221 has an elongate air blow slot 224 and the elongate air blow slot 224 is parallel to the elongate air-extraction slot 212. Moreover, the elongate air blow part 221 is in communication with an air blower 225. By means of the function performed by the air blower 225, a two-dimensional air jet can be blown vertically upward or obliquely upwards via the air blow slot 224. In implementation, through the air blow slot 224, a two-dimensional air jet also can be blown towards the rear plate 26 of the cabinet 2. The air blower 225 also can be replaced by a crossflow fan or other fluid mechanisms.
By this way, as shown in Figs.8-10, the air-extraction device 215 and the air blower 225 can be in operation simultaneously so as to have the air blow slot 224 blow air jet upwards and to have the air extraction slot 212 draw in the air jet. As a result, air can be supplied through the first air-supply space 222 and the second air-supply space 223. Besides, the left deflection plate 3 and the right deflection plate 4 can be used to guide airflow so as to form a nearly two-dimensional oblique air curtain 8 between the elongate air blow slot 224 and the elongate air-extraction slot 212. Thereby, it is able to carry upwards into the above air-extraction hood the pollutants confined between the oblique air curtain 8, and the rear plate 26, the left and the right lateral plates 23, 24 of the cabinet 2. These pollutants eventually can be exhausted via the air collector 214.
Please refer to Fig. 11, in which is shown a third embodiment of an exhaust device 1 having deflection plates. In this embodiment, a strip-shape air blow device 253 is provided at the bottom, either inside or outside the cabinet, of the front plate 25. The strip-shape air blow device 253 draws the fresh air outside the cabinet and blow the drawn air downward so as to enhance ability of preventing leakage of pollutants or high-temperature soot. In implementation, two air blow devices 253 can be provided respectively at two ends of the bottom of the front plate 25. Alternatively, as shown in Fig.11 A, when the lateral part of the front plate 25 is overlapped with a movable cabinet door 255, the air blow device 253 is provided at the bottom of the movable cabinet door 255.
Moreover, Fig.12 shows a fourth embodiment of an exhaust device 1 having deflection plates 31, 32, 41, and 42. In this embodiment, two openings 251, 253 are respectively provided in front of and in back of the cabinet 2. In other words, the two openings pass through the cabinet 2. In the space 27, a front and a rear left deflection plates 31, 32 are respectively provided in a manner of being relatively oblique to the left lateral plate 23, and a front and a rear right deflection plates 41, 42 are respectively provided in a manner of being relatively oblique to the right lateral plate 24. A first included angle θ1 is formed between the front and the rear left deflection plates 31, 32 and the left lateral plate 23. A second included angle θ2 is formed between the front and the rear right deflection plates 41, 42 and the right lateral plate 24. Besides, the front right deflection plate 41 is symmetrical to the front left deflection plate 31 while the rear right deflection plate 42 is symmetrical to the rear left deflection plate 32. Thereby, it is able to prevent the leakage of pollutants or high-temperature soot from the front or the back of the cabinet 2 so that users can conduct experiments or cook food in front or in back of the cabinet 2.
Therefore, the present invention has following advantages:

1. According to the present invention, the left and right deflection plates not only can be used to guide airflow to ensure air supply and to prevent the air entering the cabinet from flowing backwards, but they also can be used to guide effectively the airflow in the cabinet. Thereby, it is able to exhaust the pollutants or high-temperature soot effectively and to reduce the leakage of the pollutants.
2. According to the present invention, air can be smoothly guided by utilizing the first guiding plate, the second guiding plate, the first guiding part, and the second guiding part, so as to reduce the backflow occurring when the air is drawn into the opening. Thereby, it is able to prevent the pollutants or high-temperature soot from being carried out of the opening by the backflow.

As disclosed in the above description and attached drawings, the present invention can provide an exhaust device having deflection plates for reducing effectively the leakage of pollutants or high-temperature soot so as to ensure the safety in use. It is new and can be put into industrial use.
Although the embodiments of the present invention have been described in detail, many modifications and variations may be made by those skilled in the art from the teachings disclosed hereinabove. Therefore, it should be understood that any modification and variation equivalent to the spirit of the present invention be regarded to fall into the scope defined by the appended claims.

Claims

An exhaust device having deflection plates, comprising:
a cabinet, having an air-extraction hood, a bottom plate, a left lateral plate, a right lateral plate, and a rear plate, all of which define a space, where an opening is provided in front of the cabinet; an air-extraction part is provided at a bottom of the air-extraction hood; the air-extraction part has an elongate air-extraction slot facing downwards; the elongate air-extraction slot is parallel to the rear plate; and the air-extraction part is connected with an air-extraction machine for drawing air upwards;

a left deflection plate, vertically located in the space in a manner of being relatively oblique to the left lateral plate, so as to form a first included angle between the left deflection plate and the left lateral plate; and

a right deflection plate, symmetrical to the left deflection plate and vertically located in the space in a manner of being relatively oblique to the right lateral plate, so as to form a second included angle between the right deflection plate and the right lateral plate.
The exhaust device having deflection plates as claimed in claim 1, wherein a front end of the bottom of the air-extraction hood is provided with a curved first guiding part while a top of the front end of the bottom plate is provided with a curved second guiding part.
The exhaust device having deflection plates as claimed in claim 1, wherein a front plate is further provided in front of the cabinet and the opening is formed below the front plate.
The exhaust device having deflection plates as claimed in claim 3, wherein an elongate air blow device is provided at the bottom of the front plate for blowing air downwards.
The exhaust device having deflection plates as claimed in claim 1, wherein an elongate air blow part is provided in front of the bottom plate; the elongate air blow part has an elongate air blow slot with an opening facing upwards; a first air-supply space is formed between the left end of the elongate air blow part and the left lateral plate; a second air-supply space is formed between the right end of the elongate air blow part and the right lateral plate; and the elongate air blow slot is parallel to the elongate air-extraction slot so as to form a nearly two-dimensional oblique air curtain between the elongate air-extraction part and the elongate air blow part during the air-extraction machine is in operation.
The exhaust device having deflection plates as claimed in claim 1, wherein a curved first guiding plate is provided at the front end of the left lateral plate the cabinet and a curved second guiding plate is provided at the font end of the right lateral plate of the cabinet for guiding airflow into the space.
The exhaust device having deflection plates as claimed in claim 1, wherein a front end of the left deflection plate is in a position closely against a right lateral surface of the left lateral plate; a front end of the right deflection plate is in a position closely against a left lateral surface of the right lateral plate; and the first and the second included angles face towards the rear plate.
The exhaust device having deflection plates as claimed in claim 7, wherein a front end of the bottom of the air-extraction hood is provided with a curved first guiding part while a top of the front end of the bottom plate is provided with a curved second guiding part.
The exhaust device having deflection plates as claimed in claim 7, wherein a front plate is further provided in front of the cabinet and the opening is formed below the front plate.
The exhaust device having deflection plates as claimed in claim 9, wherein an elongate air blow device is provided at the bottom of the front plate for blowing air downwards.
The exhaust device having deflection plates as claimed in claim 7, wherein an elongate air blow part is provided in front of the bottom plate; the elongate air blow part has an elongate air blow slot with an opening facing upwards; a first air-supply space is formed between the left end of the elongate air blow part and the left lateral plate; a second air-supply space is formed between the right end of the elongate air blow part and the right lateral plate; and the elongate air blow slot is parallel to the elongate air-extraction slot so as to form a nearly two-dimensional oblique air curtain between the elongate air-extraction part and the elongate air blow part during the air-extraction machine is in operation.
The exhaust device having deflection plates as claimed in claim 7, wherein a curved first guiding plate is provided at the front end of the left lateral plate the cabinet and a curved second guiding plate is provided at the font end of the right lateral plate of the cabinet for guiding airflow into the space.
An exhaust device having deflection plates, comprising:
a cabinet, having an air-extraction hood, a bottom plate, a left lateral plate, and a right lateral plate, all of which define a space, where an opening is respectively provided in front of and in back of the cabinet; an air-extraction part is provided at the bottom of the air-extraction hood; the air-extraction part has an elongate air-extraction slot facing downwards; the elongate air-extraction slot is perpendicular to the left and right lateral plates; and the air-extraction part is connected with an air-extraction machine for drawing air upwards;

a front and a rear left deflection plates, respectively vertically located in the space in a manner of being relatively oblique to the left lateral plate, so as to form a first included angle between the front and the rear left deflection plates and the left lateral plate; and

a front and a rear right deflection plates, where the front right deflection plate is symmetrical to the front left deflection plate and the rear right deflection plate is symmetrical to the rear left deflection plate; and the front and the rear right deflection plates are respectively vertically located in the space in a manner of being relatively oblique to the right lateral plate, so as to form a second included angle between the front and the rear right deflection plates and the right lateral plate.