GB2478531A

GB2478531A - A ventilation hood with a movable detachable filter

Info

Publication number: GB2478531A
Application number: GB1003796A
Authority: GB
Inventors: David Alexander Shaw
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-03-08
Filing date: 2010-03-08
Publication date: 2011-09-14
Also published as: GB201003796D0

Abstract

A filter apparatus for mounting within a system ventilation hood 4 has a support (11, fig 2) attached to the ventilation hood 4 and a filter device 5 with a detachable filter 6, the device 5 being movably on the support 11 between a first operational position O and a second position L where the filter 6 can be detached from the filter device 5 (e.g. for cleaning). The filter can pivot between the two positions. An actuator with motor 17, pulleys 20, and cables 19 controls movement of the filter device 5, the cables being attached to lugs 23 on a frame 14 of the filter device so that after a filter device has been detached it can be lowered by a person standing on the floor. The ventilation system can be for a commercial kitchen.

Description

A FILTER APPARATUS AND A KITCHEN VENTILATION SYSTEM

INCORPORATING SUCH A FILTER APPARATUS

The present invention relates to a filter apparatus for use primarily, but not exclusively, in a ventilation hood of a kitchen ventilation system and to a ventilation system incorporating such a filter apparatus.

A kitchen ventilation system typically comprises ventilation ducting linked to a ventilation hood that is installed above a cooking appliance or a range of cooking appliances and food preparation tables in order to extract the hot air, steam and fumes. These fumes typically comprise grease droplets, small-scale particulate materials, undesirable odours, including heavy cooking vapours, and, from time to time, smoke.

A grease filter is a typical component of a ventilation hood as otherwise grease-laden fumes from cooking will rapidly deposit a heavy layer of grease in the hood, on the air extraction means used in the ventilation system and in any associated ducting. This would create a fire hazard as well as being unhygienic and a source of objectionable odours. The grease filter may be, therefore, the first filter of several that may be encountered by air being drawn through a ventilation system. A grease filter typically comprises a mesh or a series of baffles and is designed to operate by forcing air drawn through it to change its direction of travel abruptly prior to exiting the filter.

As the air changes direction, grease and other impurities are propelled away from the air stream and impinge upon the mesh or baffles where they either stick or run into a collection area.

One problem with such grease filters is that they are difficult to clean.

In particular, the labyrinthine path along which grease-laden air travels through the filter makes them particularly difficult to clean effectively as many of the surfaces to which the grease sticks are hidden within the body of the filter and cannot be accessed directly for cleaning. It is not sufficient, therefore, to simply wipe the exterior surfaces of the filter to cleanse it.

Preferably, the filter should be removed from the ventilation hood and thoroughly washed with soap or detergent, for example in a dishwasher.

However, in many ventilation hoods it is not always an easy task to remove the filter from the hood. In a commercial kitchen, for example as shown in Fig. 1, a ventilation hood 4 is typically located above a kitchen range 1 that comprises a variety of cooking appliances 2 and food preparation tables 3.

The hood 4 is located above the average head-height, as indicated by the outline of a human figure M in Fig. 1, and to remove a filter, such as a grease filter 6, from the hood 4 requires the person M either to use step-ladders or to stand on top of the kitchen range 1, neither of which is either acceptable or safe.

The object of the present invention is to provide a filter apparatus and a ventilation system incorporating such a filter apparatus which overcomes or substantially mitigates the aforesaid problems.

According to a first aspect of the present invention there is provided a filter apparatus for mounting within a ventilation hood of a ventilation system comprising a support adapted for attachment to the ventilation hood; a filter device that incorporates a detachable filter and that is movably mounted on the support and movable between a first position wherein the filter is retained in an operational position and a second position wherein the filter is detachable from the filter device; and an actuator that controls movement of the filter device between its first and second positions.

Preferably, the filter device is pivotafly mounted to the support and pivots relative to the support between the first and second positions.

Preferably also, the actuator comprises a motor which drives a spindle around which is wound one end of a cable, the other end of which is attached to the filter device whereby, in use, operation of the motor in one direction unwinds the cable permitting the filter device to move under the influence of gravity out of its first position and towards its second position and operation of the motor in the other direction winds the cable around the spindle to move the filter device from its second position into its first position.

Preferably also, the filter device comprises a frame in which the filter is detachably mounted.

Preferably also, the frame comprises a two-part frame wherein one part of the frame slides in and out of the other part between open and closed positions, the filter being detachable from the frame when the two parts of the frame are in an open position and being trapped within the frame when the two parts of the frame are in a closed position.

Preferably also, said other end of the cable is attached to said one part of the frame and is wound around a portion or portions of said other part of the frame whereby, in use, when the cable is unwound and the filter device moves under the influence of gravity out of its first position and towards its second position said one part of the frame is permitted to slide under the influence of gravity out of the other part of the frame to open the frame and to release the filter for detachment from the frame and when the cable is wound around the spindle to move the filter device from its second position into its first position said one part of the frame is pulled back into the other part of the frame to close the frame.

According to a second aspect of the present invention there is provided a kitchen ventilation system comprising an extraction hood; a filter apparatus mounted within the hood; a controllable air extraction means linked to the extraction hood for drawing air through the filter; and a control means and adapted to control the air extraction means; and wherein the filter apparatus comprises a support attached to the ventilation hood; a filter device that incorporates a detachable filter and that is movably mounted on the support and movable between a first position wherein the filter is retained in an operational position within the hood and a second position wherein the filter is lowered from the hood and is detachable from the filter device; and an actuator that controls movement of the filter device between its first and second positions, operation of the actuator being controlled by the control means.

Further preferred but non-essential features of the various aspects of the present invention are further described in the dependent claims appended hereto.

The various aspects of the present invention will now be described by way of example with reference to the accompanying drawings, in which:-Fig. 1 is transverse cross-section through a ventilation hood of a kitchen ventilation system that is located above a kitchen range, a filter apparatus being located within the hood with filter devices each shown in first, second and intermediate positions relative thereto; and Fig. 2 is a view to an enlarged scale of the filter apparatus located within the hood shown in Fig. 1, the filter devices of the apparatus also being shown in the same first, second and intermediate positions relative thereto.

As shown in Fig. 1, a kitchen range 1 comprises a plurality of cooking appliances 2 such as ovens, a griddle, a fryer and one or more food preparation tables 3. Mounted above the kitchen range 1 is an extraction hood 4 which comprises a plurality of filters devices 5, which typically incorporate grease filters 6. In the present example, two banks of filter devices 5 are arranged back to back and air which passes through them is collected in a plenum chamber 7 and is then led to extraction ductwork (not shown). The air is sucked through the filler devices 5 by a controllable air extraction fan (not shown) which is located within the ductwork.

The two banks of filler devices 5 are centrally located within the hood 4 and inclined at an angle towards the cooking appliance 2 or table 3 below them. However, in other arrangements they could be vertically mounted.

Between and below each of the filter devices 5 and arranged along the longitudinal axis of the hood 4 is a removable drip tray 8. Oils and greases collected by the filters 6 run or drip off the filters 6 into the tray 8 that can be periodically demounted for cleaning along with the filters 6 themselves, as is described below.

Operation of the ventilation system is controlled by a programmable controller 9 (shown schematically in Fig. i) which is operationally linked to and controls the operation of the air extraction fan and the ventilation system as a whole. The controller usually incorporates a limited manual override arrangement and may also be used to control operation of appropriately rated electric lamps 10 suitable for use in an extraction hood 4.

The lamps 10 are mounted on each side of the hood 4 adjacent each of the filter devices 5. The lamps 10 are orientated to shine down on the cooking appliances 2 and preparation tables 3 below for the convenience of the chef.

The embodiment of filter apparatus in accordance with the present invention that is shown in Figs. 1 and 2 comprises two filter devices 5, supports 11 by means of which each filter device 5 is attached to the hood 4 and an actuator, as described below, that controls movement of each filter device 5 between the first and second positions. This apparatus and its method of operation will now be described with particular reference to Fig. 2.

Each filter device 5 is attached to its support ii which is secured in an appropriately sized aperture within the hood 4, for example by screws 12. As shown in Fig. 2, each filter device 5 is pivotally mounted as at 13 to its support 11 so that it can pivot downwards out the hood 4 from a first, operational position, marked position 0 in Fig. 2, into a second lowered position, marked L in Fig. 2. The device 5 rotates through 900 between positions 0 and L, further rotation of the device 5 being prevented by the outwardly facing surface of the device 5 contacting the lower face of the support 11. Figs. 1 and 2 also show the devices 5 in intermediate, horizontal positions marked H. Each filter device 5 comprises a two-part frame 14 made up of interlinked C-shaped parts 15 and 16. The part 15 is slidably mounted within the other part i6 and can move between open and closed positions. The grease filter 6 is located within part 15 of the frame 14 such that when the two parts 15, i6 of the frame 14 are in an open position the filter 6 can be lifted out of the frame 14 but when the two parts 15, 16 of the frame 15 are in a closed position the filter 6 is trapped within the frame 14. When the filter device 5 is in the operational position 0, the part 15 of the frame 14 is uppermost and thereby retained within the part 16 under the force of gravity so that the filter 6 is trapped but when filter device s is pivoted into its lowered position L, the part 16 is uppermost so that the part 15 can slide out under the force of gravity along with the filter 6 thereby permitting detachment of the filter 6 therefrom. It will be appreciated that the part 15 only commences sliding out of the part i6 after the filter device has pivoted downwards beyond the intermediate horizontal position H. Pivoting of the filter device between positions 0 and L is under the control of the actuator which comprises a motor 17 (see Fig. i) and associated gearing (not shown) that drives a spindle 18 to which is secured one end of a cable 19, the other end of which is attached to the filter device.

In the illustrated example, the motor 17 operates both devices s simultaneously by means of individual cables 19 that are supplied for each device s and that are secured to and wound around separate pulleys 20 mounted on the spindle 18. Any number of devices 5 in banks within a hood 4 can be operated simultaneously by a similar arrangement.

From the pulley 20, each cable 19 passes around two small pulleys 21 attached to lugs 22 on opposite sides of the part 16 of the frame 14 and has its other end secured to a lug or tag 23 formed on the part 15 of the frame 14.

One of the pulleys 21 is located adjacent the pivot point 13 and the cable 19 passes around this after it has passed around the opposite pulley 21 and before its end is connected to the lug 23.

In use, the cables 19 are wound around the pulleys 20 so that the filter devices 5 are retained in their operational, first position 0, as shown in Fig. 1. The hood 4 is then in a position ready for use as part of the ventilation system under control of the controller 9. However, when it is desired to wash or exchange the grease filters 6, the extraction fan should be switched off and the controller 9 instructed commence operation of the motor 17 in order to lower the device s from position 0 to position L. On operation of the motor 17 to unwind the cables 19 from the pulleys 20, the filter devices pivot downwardly about their pivot points 13 under the force of gravity at a speed determined by the speed of the motor 17 its associated gearing. Once the devices have reached their lowermost positions L, further unwinding of the cables 19 permits the part 16 of the frame 14, along with the filter 6, to slide out of the part i under the force of gravity. The filter 6 is thereby lowered into a position where it can be detached from the frame 14 by a person standing on the floor adjacent the range 2 without having to resort to the use of a stepladder or similar means.

A handle 24 is secured to the filter 6 to facilitate this. The filter 6 can then be taken away for washing.

When it is desired to place the hood 4 back in a position ready for use, the motor 17 is operated to wind the cables 19 around the pulleys 20 by running the motor 17 in the opposite direction. As each cable 19 is wound up, the part 16 of the frame 14 to which it is attached is pulled back into the part until the frame 14 is closed. This traps the filter 6 within the frame 14.

Thereafter, further winding of the cable 19 around the pulley 20 pivots the ifiter device 5 about its pivot point 13 so that it moves from its lowermost position L back into its operational position 0.

It will be appreciated that ventilation hoods 4 can be manufactured incorporating a filter apparatus according to the invention or such a filter apparatus can be retro-fitted into an existing ventilation hood, as appropriate by replacing their existing static filter devices by one or more in accordance with the invention.

It will also be appreciated the actuator could take other forms. For example the actuator may comprise a motor-driven worm drive that acts on a toothed wheel connected to the frame 14. Such an arrangement would drive the filter device between its first and second positions rather than relying on the influence of gravity.

It will further be appreciated that whilst the filter 6 is described above as a grease filter any other form of filter could be used in the filter apparatus, as appropriate.

Claims

CLAIMS1. A filter apparatus for mounting within a ventilation hood of a ventilation system comprising a support adapted for attachment to the ventilation hood; a filter device that incorporates a detachable filter and that is movably mounted on the support and movable between a first position wherein the filter is retained in an operational position and a second position wherein the filter is detachable from the filter device; and an actuator that contro's movement of the ifiter device between its first and second positions.
2. An apparatus as claimed in Claim 1, wherein the filter device is pivotally mounted to the support and pivots relative to the support between the first and second positions.
3. An apparatus as claimed in Claim 1 or Claim 2, wherein the actuator comprises a motor which drives a spindle around which is wound one end of a cable, the other end of which is attached to the filter device whereby, in use, operation of the motor in one direction unwinds the cable permitting the filter device to move under the influence of gravity out of its first position and towards its second position and operation of the motor in the other direction winds the cable around the spindle to move the filter device from its second position into its first position.
4. An apparatus as claimed in any of Claims 1 to 3, wherein the filter device comprises a frame in which the filter is detachably mounted.
5. An apparatus as claimed in Claim 4 when dependent on Claim 3, wherein the cable of the actuator is connected to the frame.

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6. An apparatus as claimed in Claim 4 or Claim 5, wherein the frame comprises a two-part frame wherein one part of the frame slides in and out of the other part between open and closed positions, the filter being detachable from the frame when the two parts of the frame are in an open position and being trapped within the frame when the two parts of the frame are in a c1osed position.
7. An apparatus as claimed in Claim 6 when dependent on Claim 5, wherein said other end of the cable is attached to said one part of the frame and is wound around a portion or portions of said other part of the frame whereby, in use, when the caMe is unwound and the filter device moves under the influence of gravity out of its first position and towards its second position said one part of the frame is permitted to slide under the influence of gravity out of the other part of the frame to open the frame and to release the filter for detachment from the frame and when the cable is wound around the spindle to move the filter device from its second position into its first position said one part of the frame is pulled back into the other part of the frame to close the frame.
8. An apparatus as claimed in any of Claims 1 to 7, comprising a plurality of filter devices the movement of which is controlled simultaneously by the actuator.
9. An apparatus as claimed in any of Claims 1 to 8, wherein the detachable filter is a grease filter.
10. A kitchen ventilation system comprising an extraction hood; a filter apparatus mounted within the hood; a controllable air extraction means linked to the extraction hood for drawing air through the filter; and -11 -a control means and adapted to control the air extraction means; and wherein the filter apparatus comprises a support attached to the ventilation hood; a filter device that incorporates a detachable filter and that is movably mounted on the support and movable between a first position wherein the filter is retained in an operational position within the hood and a second position wherein the filter is lowered from the hood and is detachable from the filter device; and an actuator that controls movement of the filter device between its first and second positions, operation of the actuator being controlled by the control means.
ii. A filter apparatus for mounting within a ventilation hood of a ventilation system substantially as described herein with reference to the accompanying drawings.
12. A kitchen ventilation system comprising a filter apparatus substantially as described herein with reference to the accompanying drawings.