Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24C—DOMESTIC STOVES OR RANGES ; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
  • F24C15/00—Details
  • F24C15/20—Removing cooking fumes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B15/00—Preventing escape of dirt or fumes from the area where they are produced; Collecting or removing dirt or fumes from that area
  • B08B15/02—Preventing escape of dirt or fumes from the area where they are produced; Collecting or removing dirt or fumes from that area using chambers or hoods covering the area

Definitions

• the present invention relates to a device in casings fo sucking air containing impurities away from a region, such as working place, for example at a kitchen grate, under or nea the casing, said device comprising a casing downwardly open, a least a suction opening connected to a suction member fo generating an air flow from below, into the casing and ou through the suction opening for conducting air away from th device, means for conducting a part of the air sucked from th interior of the casing back to the region of a lower edge of side wall of the casing and members for directing this air as stream from said edge towards the interior of the casing, s that secondary air flows into the casing are induced at it edge region.
• the cold air in said air stream may give rise to so called cold fall phenomena inside the casing, and the total amount of air which has to be sucked away gets larger than if it were possible to recirculate a part of the air sucked and use this to form the air stream for the ejector effect.
• Devices being successful in this respect are known through US patent 4 050 367 and GB 2 169 697 A. The efficiency of these known devices is good, but could be further improved.
• the object of the present invention is to improve a device of the type mentioned in the introduction, so that the quotient amount of impurities divided by the total amount of air sucked away will be even higher than in the devices of the kind already known. According to the invention this object is obtained by a devic which is provided with the characteristics defined in th characterizing part of the appended claim 1.
• Fig 1 is a schematic cross section view of a first embodimen of the device according to the invention.
• Fig 2 is a view corresponding to Fig 1 of a second embodimen of the invention.
• Fig 3 is a perspective view of an insert used in the devic according to Fig 2, in which some portions are broken away fo illustrating the construction of the insert
• Fig 4 is a view corresponding to the views according to Figs and 2 of a third preferred embodiment of the device accordin to the invention.
• the device according to the invention shown in the figures wil here be called kitchen grate casing, which is not to be under ⁇ stood as limitative.
• the parts common to the different embodi ments have been provided with the same reference numerals.
• the kitchen grate casing shown in Fig 1 comprises a substan ⁇ tially box-shaped casing 1 downwardly open.
• the kitchen grate casing has mirror image symmetry with a vertical mirror image symmetry plane extending in the longitudinal direction of the casing 1, i.e. perpendicularly to the drawing plane.
• a V-shaped filter house 2 projects downwardly from the upper limitation of the casing and towards the casing opening 3 in the middle of the casing.
• the filter house 2 is elongated and extends paral ⁇ lel to the side walls 4 of the casing over substantially the entire length of the casing.
• the filter house 2 is provided with first suction openings 6 covered by filters 5 absorbing smell and other impurities.
• the filters 5 are disc-like and constituted by conventional filter elements adapted for the particular task.
• the filter house is terminated by an evacuating opening 8 covered by a filter 7 to an exhaust air conduit 9 connected to a suction member, for example the main fan of the main ventilation system of the premises or the building in question.
• a second suction opening 10 is arranged in the upper limitation wall of the casing on each side of the V-shaped filter house 2. This suction opening is also covered by a filter 11 of the type similar to the type of the filters 5 and 7 and it is directed substantially vertically downwardly towards the opening of the casing.
• the second suction opening 10 is connected to a second suction member in the form of a fan 12 through an intake 13
• the outlet 14 of the fan emerges into a distributing chamber 1 extending over substantially the entire length of the side wal 4.
• the distribution chamber has three elongated limitatio walls, two of which are the side wall 4 of the casing and th upper limitation wall thereof and these are interconnected b means of an inclined wall 16.
• the inclined wall 16 is provide with a succession of openings 17 extending over substantiall the whole length of the wall, a section according to Fig being carried out through such an opening.
• a directing plate 1 is arranged on the inclined wall 16 outside the distributio chamber so as to divert and direct air coming out of th openings 17, so that it gives rise to air flows substantiall being a tangent to the outside of the inclined wall 16.
• a negative pressure will be created in the filte house 2 by the suction member connected to the exhaust ai conduit 9 and a primary air flow from below and into the casin towards the first suction openings 6 will be produced.
• This ai flow is indicated by several arrows 19.
• a part of the air flowing towards th suction opening 9 will divert towards the second suctio opening 10 (see arrow 20).
• the main part of this air passes through the filter 11, in which the greatest part of it impurities is caught, whereupon this air is recirculated to th casing through the distribution chamber 15.
• the comparatively concentrated ai flow emanating from the fan 12 will be distributed substan tially uniformly over the entire length of the chamber an flowing out of the openings 17 in the direction indicated b the arrow 21.
• an air stream with the sam width as the length of the side wall 4 is formed, but it has comparatively small dimension in the direction perpendicula thereto. Owing to the fact that air flowing along a wall has tendency to be attracted by the wall and follow this, an ai stream along the side wall 4 downwards towards the lower edge of the casing is created.
• a directing plate 23 extending over substantially the entirety of this edge is so arranged that it diverts said air stream substantially in the direction towards the first suction opening 6 (arrows 24).
• the air stream from the lower edge 22 of the side wall 4 in the direction upwardly/inwardly towards the interior of the casing obtained through this arrangement will induce secondary air flows from the outside of the casing in the edge regions thereof and into the casing towards a first suction opening 6.
• the fact that an air stream draws surroun ⁇ ding air into secondary air flows is usually called the ejector effect.
• the arrows 25 indicates air flows into the casing produced by said ejector effect. Thanks to this it will be possible to suck air containing impurities and located in these regions into the casing without the necessity of creating a disproportionately low negative pressure in the filter house 2, with removing of enormous amounts of clean air.
• Another advantage of this kitchen grate casing consists in that a part of the air diverted towards the suction opening 10 through the ejector effect of the air flowing out of the openings 17 will be additionally diverted (arrow 26) and drawn into and follow the air stream downwardly towards the edge 22. In this way additional air quantities will be joining the air stream (for example arrow 27) and a rotating air movement will be produced in the room of the casing between the edge 22, the opening 10 and the walls 16 and 4.
• These rotating air flows or streams are very advantageous, since they retain particles contained in the air inside the casing and also raise the air flows inside the casing in an effective way. Furthermore, they prevent effectively parts of the air stream flowing downwardly towards the edge 22 from disappearing out through the opening 3 of the casing.
• FIG. 2 A second advantageous embodiment of the device according t the invention is shown in Fig 2.
• the part 10-18 of the kitchen grate casing according to Fig 1 have bee replaced by an insert 28 manufactured in advance, which i shown more in detail in Fig 3.
• the insert is designed to b introduced into kitchen grate casings already existing and b retained by means of suitable retaining members, in order to b easily removed when this is desired, for example for cleanin purposes.
• Such an insert may be arranged in either the positio according to Fig 2 or the one according to Fig 4.
• the inser has a second suction opening 10 covered by a flat filter 11 This suction opening is connected to a fan 12, which blows ou air sucked in through the opening 9 into a distribution chambe 29.
• the distribution chamber 29 is divided into two halves by finely perforated plate 30, through which the air from the fa 12 has to pass in order to reach the openings 31 in one end o the chamber towards the interior of the casing.
• the perforate plate 30 contributes additionally to a uniform distribution o the air stream reaching the openings 31 over all of the ope nings. It appears from Fig 3 what the openings look like an how they are arranged, said filter 11 being omitted in thi figure.
• an elongated directin plate 32 is so arranged in the proximity of the openings 31 that the air stream coming out of the insert is directe downwardly along the side wall of the casing and an air strea as well as rotating air movements similar to the ones in th device according to Fig 1 are created.
• the directing plate 3 is advantageously adjustable for adjustment of the direction o the air stream.
• a further advantage of the rotating air flows and the ai stream moving along the side wall 4 consists in the fact that if the side wall is made of a material with a high therma conductivity, a great part of the heat content of the air ma be led away to the room outside the casing, so that the ai carried away through the exhaust air conduit 9 has a slightly lower temperature than the rest of the air of the room.
• FIG 4 It is shown in Fig 4 how an insert according to Fig 3 manu ⁇ factured in advance has been arranged in a kitchen grate casing with the suction opening 10 substantially horizontally directed and the openings 31 located in the vicinity of the lower edge 22 of the side wall 4.
• This insert is provided with a directing plate 32 ' according to Fig 3, which is adjustable (the screw 33) and so directed that it together with a directing member 34 replacing the directing plate 23 directs the air stream from the openings upwardly/inwardly substantially towards the first suction opening 6.
• the insert 28 in Fig 4 is preferably kept in place by resting on a lower edge portion 35 of the casing and upper guiding members not shown projects downwardly from the top of the casing and retain the insert in lateral direc ⁇ tion, so that the latter after removing a short wall of the casing may be pushed into the same along the side wall 4 or through the opening 3.
• the air flows inside the casing are directed more upwardly thanks to the high location of the second suction opening 10.
• the -embodiments described above relate to casings intended to be located in a room with both side walls 4 out in the room, but in the case that the casing is to be placed close to or against a wall the device only consists of a half of the devices shown. It will then be cut off in the mirror image symmetry plane, where a wall for application on the room wall in question is arranged. Preferably, this wall will then limit the filter house from which the exhaust air conduit emanates.
• the first suction member may be constituted by the main fan o the ventilation system of the building, but a separate fan ma just as well be arranged for this task.
• the openings 17 and 31, respectively, could be one singl continuous elongated slit, even though a plurality of hole would be advisable from the stability point of view.
• the filters being a part of the device are of course adapted t their purposes, so they could for example have surfaces actin as catalyzers in a reaction in which a toxic compound of th air is converted to a harmless compound.
• the casing 1 could also be circular, so that the opening 3 wil be circular, but all other shapes of the casing desired are o course possible.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Ventilation (AREA)
• Filtering Of Dispersed Particles In Gases (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Exhaust Gas After Treatment (AREA)

Priority Applications (5)

Applications Claiming Priority (1)

Publications (1)

Family

ID=20369858

Family Applications (1)

Country Status (7)

Cited By (11)

Families Citing this family (2)

Citations (7)

• 1987
  • 1987-10-13 SE SE8703959A patent/SE459324B/sv unknown
• 1989
  • 1989-04-10 DE DE68916654T patent/DE68916654T2/de not_active Expired - Lifetime
  • 1989-04-10 EP EP89905812A patent/EP0466687B1/en not_active Expired - Lifetime
  • 1989-04-10 WO PCT/SE1989/000188 patent/WO1990011844A1/en active IP Right Grant
• 1991
  • 1991-09-19 DK DK161691A patent/DK161691A/da not_active IP Right Cessation
  • 1991-09-23 FI FI914443A patent/FI95670C/fi not_active IP Right Cessation
  • 1991-10-10 NO NO913962A patent/NO174173C/no unknown

Patent Citations (7)

Non-Patent Citations (1)

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