GB2249493A

GB2249493A - Cooker canopies

Info

Publication number: GB2249493A
Application number: GB9118520A
Authority: GB
Inventors: Richard John Isaac
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-08-31
Filing date: 1991-08-29
Publication date: 1992-05-13
Also published as: GB9118520D0

Abstract

A cooker canopy of commercial size comprises a rigid outlet plenum made up of fixed panels, one of which carries one or more separation elements 5 (e.g. filters) and is pivotable and/or otherwise removable to allow access into the plenum for cleaning. The movable panel 2 may be in separate sections and constitutes at least 80% of the area of the corresponding plenum wall. It may be hinged to the plenum at the top, or pivotted at the side, or laterally slidable or simply secured by removable wing nuts. If hinged, the hinges may be demountable to enable complete removal. The filters in turn may be hinged to the panel. <IMAGE>

Description

Filter Panel for Cooker Canopies The present invention relates to a filter panel for a cooker canopy, notably to a pivoting and/or removable panel for a commercial cooker canopy.

Many forms of cooker canopy exist for use in commercial kitchens. A commercial cooker canopy is distinguished from a domestic cooker hood by its size, it has a horizontal plan area of at least 1.5 square metres; by the total flow of air through the filter elements carried by the hood, it has a flow rate of at least 20 cubic metres of air per minute; and by the total area of the filter elements, which is at least 0.25 square metres. The term "commercial cooker canopy" is therefore used herein and in the claims to denote such structures as distinguished from domestic cooker canopies which lack one or more of these essential features. Furthermore, commercial cooker canopies are used with air extraction systems designed for continuous use over periods of up to 18 hours or more.

In general, commercial cooker canopies comprise a rigid canopy body made from a series of panels secured together in the desired configuration and having one or more filter elements carried by one of the fixed panels. Air is drawn from the cooking area served by the canopy through the filter element to remove grease and other contaminants from the air above the cooker. Typically, the air is drawn through the filter elements by means of a fan into a plenum chamber located behind the filter elements and thence is carried through ducting and discharged under the influence of the fan to the outside air. The filter elements are mounted in one of the fixed panels of the canopy construction which define the walls of the plenum chamber.

A major problem with all forms of commercial cooker canopy is the build up of grease in the plenum chamber and on the filter element. The filter elements are therefore demountably mounted in the structure of the canopy so that they can be readily removed for cleaning. The removal of the filter elements also provides a measure of access to the interior surfaces of the plenum chamber and to the associated ductwork through which the air from the plenum chamber is vented to the environment or to a treatment unit from which the treated air is to be re-cycled.

However, this access is often restricted and does not enable comprehensive cleaning of the chamber walls and ductwork to be achieved. As a result, commercial cooker canopies present not only a fire hazard due to the accumulation of grease therein, but also a health hazard due to the decomposition of the grease and the growth of bacteria such as salmonella within the grease deposits.

In order to reduce these hazards, it has been proposed to build water sprays into the canopy structure to achieve hot water washing of the walls of the chamber and ducting on a regular basis. However, this is a complex and expensive form of construction and does not wholly solve the problem of grease build up in the canopy.

The present invention proposes a form of construction for a commercial cooker canopy which reduces the above problems.

The present invention provides in a commercial cooker canopy as defined above, constructed from a series of fixed panels fixed together to form a rigid structure and having one or more air contaminant separation elements through which contaminant laden air is to be drawn into a plenum chamber bounded by at least one wall panel of the canopy, the improvement which comprises forming substantially all of that wall panel carrying the separation elements and forming one wall of the plenum chamber as a removable and/or pivotable wall secured to the canopy structure or the structure upon which the canopy is to be mounted by securing means.

In one form of embodiment, the removable wall is mounted by pivot means whereby when the securing means is released the removable wall is adapted to pivot from a position at which it forms part of the wall of the plenum chamber to a position beyond the vertical whereby it forms an open wall to the plenum chamber so that an operator can gain direct access to the interior of the walls of the plenum chamber through the opening thus formed.

In another form of embodiment, the wall is mounted in position by readily releasable bolts or the like, and has one or more portions each carrying one or more filter elements and which can be pivotted outwardly to provide access to the plenum chamber, each pivotting portion securing in its closed position by quick release securing means.

In yet another form of embodiment, the complete wall carrying one or more filter elements is adapted to slide in and out of position between guides provided on the canopy at the front of the plenum chamber, preferably horizontal guides, so that the wall is slidable laterally into and out of its operative position.

The air contaminant separation means for use in the canopy of the invention can be conventional mesh or paper element type filters in which grease and other contaminants are trapped as the air stream is drawn through the fine pores or passageways through the filter element. However, other forms of separation equipment, for example impact or cyclonic separators where the air stream is caused to undergo a sharp change in flow direction, can be used. In such separators, the heavier contaminant particles are unable to change direction rapidly and impinge on a wall of the separator and are held there. For convenience, the invention will be described hereinafter in terms of the use of a simple filter mesh formed as a generally rectangular planar filter element.

The filter mesh can be housed within a suitable steel or aluminium or other frame for ease of handling. Such filter elements are readily available and can be used in their commercially available forms.

The cooker canopy of the invention can be of conventional shape, size and design according to the area it is to serve, as is known in the art. For example, the canopy can be a conventional rectangular construction for mounting along the wall above a bank of cookers in a kitchen; or an L shape for mounting in the angle of a corner of the kitchen; or a free-standing unit suspended from the ceiling or supported on pillars from the floor to serve a cooker unit in the centre of the room. The canopy can have a laterally extending portion to enlarge the catchment area served by the canopy and can be provided with lighting or other features found on conventional designs of commercial cooker canopy.For example, it will usually be necessary to provide the body of the canopy with an air outlet from the plenum chamber which can be connected by suitable ducting to a fan or other air moving device as is known in the art; or with a grease run off tap serving the base of the plenum chamber or other suitable location(s).

The canopy of the invention can be made from conventional materials using conventional techniques and is of a rigid or non-collapsible form.

The cooker canopies of the invention are characterised in that the wall carrying the filter elements and forming one wall of the plenum chamber is removably and/or pivotally mounted on the remainder of the construction of the cooker canopy so that substantially the whole of that wall can be removed or at least swung aside sufficiently to expose the interior of the plenum chamber and to form an open wall to the plenum chamber of sufficient size to enable an operator to gain ready access to the interior of the canopy. In the case of a pivotting wall, this will require that the wall pivot at least beyond the vertical when the canopy is installed. It is also preferred that the filter elements are demountable from that wall so that they can be cleaned separately using conventional techniques.

In the case of a pivotting wall, this can provide substantially the whole of the wall of the plenum chamber, i.e. at least 80% of the area of that wall of the plenum chamber.

However, it will be appreciated that part of the wall may be required to provide support for the pivotally mounted part.

Thus, a peripheral flange of the wall can remain attached to the main body of the canopy to provide means for securing the pivotting portion of the wall in position. Usually, this flange extends around the periphery of the pivotting wall to provide a seal when the wall is in the closed position.

If desired, the flange and/or the pivotting wall can carry rubber or similar sealing strips to ensure an airtight seal when the pivotting wall is in the closed position bearing against the flange. Alternatively, the plenum wall can be formed as a series of pivotting sections interrupted by fixed portions of the wall, provided that the fixed portions of the wall do not have a width greater than 10 to 30 cms to allow ready access to the rear of those fixed portions.

In many designs of cooker canopy a grease collection trough runs around the internal base lip of the canopy walls to collect any grease deposited on the walls. It will therefore usually be preferred that where any flange is provided around the periphery of the removable section(s) of the wall, this be at least sufficient to carry the edge of the removable section(s) of the wall clear of the grease trough. If desired, the peripheral flange may be provided in the form of a peripheral box section to impart rigidity and structural strength to the canopy around the opening formed when the removable section(s) of the wall are removed.

The removable and/or pivotting wall can be of the same design and construction as the other walls of the cooker canopy.

However, since this wall is to carry the filter elements, it will usually be desired to provide support means, for example bars or a support framework rivetted or otherwise attached to the face of the wall, to locate and support the filter elements and to reduce flexing and distortion of the wall due to the load of the filter elements and to heat from the cooker(s) the canopy serves. It may also be preferred to provide grease drainage holes or the like along at least part of the lower edge of the removable section(s) of the wall to allow grease which may collect on the face of the wall to drain into the grease collection gutters carried by the fixed portion of the canopy construction.

Clips or other forms of mechanical latch or other means can be provided for securing the removable and/or pivotting wall to the canopy in the closed position. Alternatively, the lower lip of a pivotting wall can be configured to seat against the wall of the building upon which the canopy is mounted and the pivotting wall retained in the closed position by screws or other fasteners attached to the wall of the building.

The wall of the canopy is pivotted using any suitable hinge or other pivot mechanism, which can be fixed or demountable as stated above. Thus, the pivotting wall can be attached to a frame member of the canopy construction located at the intersection between two panels of the canopy or at some other convenient point on the canopy construction, using a series of hinges along one edge thereof or by means of one or more pivot pins passing through a peripheral flange or pivot trunnion carried by the pivotting section of the wall intermediate its edges. The wall can be pivotted along one side edge thereof. However it is preferred that the wall be pivotted along its upper or lower edges so that the wall pivots downwardly under gravity and any twisting on the hinge line is reduced. It is particularly preferred that the wall be pivotted along its-upper edge.

The pivotting device can be a continuous hinge, up to 6 ft long or more -if needed, and of the mild steel type which has to be dismantled and reversed with the pins re-inserted to make it work correctly, so that the filter panel will move outward, past the vertical position.

In a bolt-on version of a hinged filter wall, a vertical hinge assembly can be installed on one or more wall sections so that access can be gained to one or more contiguous sections of the canopy plenum chamber, as is necessary and suitable for a particular situation.

The canopy having the removable and/or pivotting wall can be provided with other features to assist access to the interior of the plenum chamber. Thus, the canopy can carry one or more catches or the like which retain the pivotting wall in the fully open position, or the pintles can be disengageable from the canopy hinge assembly to enable removal of the wall. Wing nuts and steel bolts are suitable for use to mount a fully removable wall.

Some embodiments of the invention will be described by way of example with reference to the accompanying drawings in which: Figure 1 is a part sectioned perspective view of a typical sloping-front type commercial cooker canopy incorporating the invention; Figure 2 is a transverse cross-section through the canopy; Figure 3 is a detail from the cross-section of Figure 2; Figure 4 is a transverse cross-section of the canopy in Figure 1, showing alternative hinge positions; Figure 5 shows an 8 ft example of a low-ceiling type canopy with-a hinged filter panel in the closed position; Figure 6 shows the hinged filter panel released and open; Figure 7 shows the hinged filter panel fully open which gives access to the plenum chamber for cleaning and maintenance where an extractor fan is fitted;; Figure 8 shows application of the invention to a dual panelled canopy which may be suitable in some applications i.e. in a bank of canopies or in L shaped island types or larger canopies; Figure 9 shows a bolt-on version of the filter panel which can be attached and removed when necessary; Figure 10 shows an alternative bolt-on version of the filter panel; Figure 11 shows a further embodiment of bolt-on panel; Figure 12 shows a filter panel with a multiplicity of hinged sections, Figure 12A showing one hinged section in enlargement; Figure 13 is a composite figure showing two further possible embodiments; Figures 14A to 14C respectively show three possible embodiments of canopy for receiving a slide-in filter panel itself shown in Figure 14D; and Figure 15 shows a slide-in filter panel in course of insertion into a canopy.

With respect to the bolt-on version of the panel shown in Figure 9, this is a less expensive version of the hinged panel, and a vertical hinge can be incorporated, if needed, which gives access to individual sections of the canopy plenum chamber.

The hinged filter panels of Figures 5 to 8 are shown fitted in a low ceiling type canopy as it is easier to see the use and application of the panel. However, both these types of filter panel can be installed in any type of modular/box type canopy, i.e. sloping-front, rectangular box type, Lshaped, low ceiling, island type and versions of all modular type canopies.

Referring first to Figures 1 to 4, the main body of the canopy comprises a number of panels 1, la, ib etc. rivetted or otherwise fixed together at their edges, either by folding over the edges of the panels to provide flanges to which panels are fixed, or by fixing the panels to angle members forming an internal framework for the canopy, so as to form a rigid structure. The canopy is provided with an internal inclined panel 2 which extends for the length of the interior of the canopy. This defines, with the side, the back and the top panel, the canopy plenum chamber 3 into which air is drawn by means of a fan (Figure 7), extracting air through an outlet spigot 4 (Figures 1, 2 and 7) and associated ductwork (not shown).

The panel 2 carries a series of removable filter elements 5 which can be of the wire mesh or impact separator type. The elements 5 are demountably fixed within apertures in the panel using any suitable means, e.g. aluminium sliding dead bolts or suitable screws, etc. Panel 2 is connected to the roof panel or the front panel of the body of the canopy by means of a hinge or hinges 10 along its top edge so that the panel can be swung downwardly beyond the vertical as shown dotted in Figure 2. Alternatively, the pivotting wall 2 can be carried at its sides by lateral pivot pins l0a as shown in Figure 4. If desired, the position of the pins l0a can be selected from several alternative positions as shown in Figure 4, so that the wall 2 can pivot about different points for different configurations of canopy and cooker.

The hinges supporting the panel 2 need not be mounted directly upon the front or top panels of the canopy, but can be mounted upon a peripheral flange 11 which aids seating of the panel 2 in the closed position. As shown in Figure 3, the periphery 21 of the panel 2 can extend over the lip of the flange to provide an overlapping seal area and either the flange and/or the periphery of the panel 2 can carry a rubber or similar seal member 22.

The panel 2 can be held in the closed position seating against the flange 11 by alloy bolts, screws or the like 12.

Alternatively, the lower lip of panel 2 can be secured directly to the wall of the building upon which the canopy is mounted, as shown in Figure 3, and the lower lip can be secured by screws or other fastenings and fixed to the wall of the building by conventional methods, e.g. a wall plug 23 as shown. A rubber seal 22 can be mounted along the lower lip of the panel 2 or along the contact line of the lip with the flange 11, to provide a seal when the panel 2 is in the closed position.

When it is necessary to gain access to the interior of the chamber 3 in order to clean the chamber, the aluminium bolts/ screws 12 can be released and the panel 2 can be swung downwardly as- shown in Figure 2, thus exposing the interior of the chamber. Since the entry into the chamber is obstructed only by the flange 11, access is readily achieved and the dead areas behind wall 2, i.e. the back face of flange 11, can be reduced to a minimum by suitable design and sizing of the panel and the flange. If necessary, the panel 2 can be sub-divided longitudinally into two or more portions separated by fixed sections 13 as shown in Figure 1.

Again, by suitable sizing of those fixed panels, the dead area behind panel 2 can be reduced to a minimum having regard to the structural strength required on the one hand and ease of cleaning on the other.

If desired, a clip for retaining the panel in the open position can be provided.

The invention can be applied to the construction of new cooker canopies. However, the invention can also be applied to existing canopies to provide the benefits of improved access to the interior of the plenum chamber for cleaning and maintenance purposes. Thus, the fixed wall carrying the filter elements in an existing canopy can be cut away to form an open face to the plenum chamber, optionally with part of the periphery of that wall remaining to provide the flange 11 shown in Figure 2. The lip of the cut away portion of the wall can be provided with a reinforcement flange, seals and hinges or other mounting means and the panel re-mounted on the canopy as a pivotable removable panel 2.

From another aspect, the present invention provides a method for cleaning the interior surfaces of the walls of the plenum chamber of a commercial cooker canopy, which method comprises releasing a removable wall of a canopy or modified canopy of the invention, pivotting the removable wall to beyond the vertical to form an open wall to the plenum chamber through which an operator can gain access to substantially all the interior surfaces of the plenum chamber and carrying out a cleaning operation on the interior surfaces of the plenum chamber.

The cleaning operation can be any suitable operation, for example a hot water wash with detergent or de-greasing solutions or steam cleaning using a conventional steam cleaning device.

A manual method of cleaning is preferred, which involves using scourers, cloths, water and the correct de-greasing chemical, and which can be carried out with ease by an operative.

A bolt-on version of the hinged filter panel is shown in Figure 9, which may be suitable in certain applications.

This panel 24, incorporating filters 25, can be fitted in numbers of one or more and can also include a vertical hinge assembly 26 which gives access to a single or certain part of the plenum chamber of the canopy for deep cleaning and maintenance purposes. The hinged sections are fitted in the same or similar way as the horizontally hinged panels of Figures 1 to 8 with aluminium dead bolts of a suitable size or screws 28.

Figure 10 shows an alternative version of bolt-on panel 30 incorporating removable filters 32. The panel fixes in position by means of aluminium dead bolts or the like 28, and incorporates a horizontal hinge 34.

The bolt-on panel 36 of Figure 11 fixes in position by bolting means 28 and incorporates a filter 37 on a frame 38 which folds downwardly on a hinge 40. The filter frame fastens in its closed position by means of a quick-release over-centre clip 41. The complete panel 36 is readily removable to give better access to the plenum chamber.

Another version of the filter panel is shown in Figure 12.

Here the panel 42 incorporates a plurality of filter frames 44 carrying filters 45 and openable on vertical hinges 46.

Reference 47 denotes the peripheral flanges of the main structure of the canopy 48 to which the panel 42 is secured and against which the filter frames close, being held in the closed position by magnetic catches 49, 49A. When opened, the filter frames give access to the plenum chamber 50.

Figure 13 shows another version of the filter panel 52 of a canopy 53, wherein the filters 54 are incorporated in pyramidal-shaped units 56 removable from between bottom grooves 57 and top releasable fasteners 58. Alternatively, the pyramidal units may be hingedly mounted along their bottom edges, as indicated at 60.

Figures 14A to 14C show three possible types of canopy, namely a sloping-front canopy 60, a box-shaped canopy 62 and a low-ceiling type canopy 64, all of which can be adapted by means of lower and upper grooves 65, 65A to receive a removable slide-in panel 66 carrying filters 68 (see Figure 14D). Figure 15 shows a panel 66 partly slid out of a canopy 67, revealing the interior plenum chamber 69.

Various other forms of canopy incorporating removable and/or pivotting filter panels are possible within the scope of the invention hereinbefore defined.

Claims

1. A commercial cooker canopy as hereinbefore defined constructed from a series of fixed panels fixed together to form a rigid structure and having one or more air contaminant separation elements through which contaminant laden air is to be drawn into a plenum chamber bounded by at least one wall panel of the canopy, the improvement which comprises forming substantially all of that wall panel carrying the separation elements and forming one wall of the plenum chamber as a removable and/or pivotable wall secured to the canopy structure or the structure upon which the canopy is to be mounted by securing means.

2. A canopy according to claim 1, wherein the removable wall is mounted by pivot means whereby when the securing means is released the removable wall is adapted to pivot from a position at which it forms part of the wall of the plenum chamber to a position beyond the vertical whereby it forms an open wall to the plenum chamber so that an operator can gain direct access to the interior of the walls of the plenum chamber through the opening thus formed.

3. A cooker canopy according to claim 1 or claim 2, wherein the removable and/or pivotable wall provides at least 80% by area of the total wall carrying the separation elements and forming a wall of the plenum chamber.

4. A cooker canopy according to any of claims 1 or 2 or 3, wherein the separation elements are filter elements.

5. A canopy as claimed in any of the preceding claims, wherein the removable wall is formed in two or more sections.

6. A canopy as claimed in claim 1, wherein the removable wall panel is mounted to the canopy by means of one or more hinge assemblies comprising a pintle removably engaging a gudgeon, whereby the panel can be pivotted to provide the opening to the plenum chamber and can be demounted from the canopy by separating the hinge assembly.

7. A canopy as claimed in any of the preceding claims, wherein the removable wall is inclined to the vertical when in the closed position and is secured to the canopy by means of one or more pivot means located at or adjacent its upper edge whereby it can pivot to the open position under the influence of gravity.

8. A canopy as claimed in claim 1, wherein the removable panel incorporates filter-carrying sections supported on vertical hinges.

9. A canopy as claimed in claim 1, wherein the removable panel incorporates filter-carrying sections supported on horizontal hinges.

10. A canopy as claimed in any of claims 1 to 9, wherein the complete-filter carrying wall of the canopy is adapted to mount in position by securing bolts or the like.

11. A canopy as claimed in claim 1, in which the filtercarrying panel is adapted to slide in and slide out of position in front of the plenum chamber, preferably in a lateral direction.

12. A canopy as claimed in claim 1, substantially as hereinbefore described.

13. A canopy substantially as hereinbefore described with respect to and as shown in any one of the accompanying drawings.

14. A commercial cooker canopy as hereinbefore defined which has been modified by cutting that wall carrying the air contaminant separation elements and forming one wall of the plenum chamber to form a demountable wall extending over at least 80% of that wall of the plenum chamber which can be pivotted to permit access to the interior of the plenum chamber by an operator.

15. A method for cleaning the interior surfaces of the walls of the plenum chamber of a commercial cooker canopy as hereinbefore defined, which method comprises releasing a removable wall of a canopy as claimed in any one of the preceding claims, pivotting the removable wall to beyond the vertical to form an open wall to the plenum chamber through which an operator can gain access to substantially all the interior surfaces of the plenum chamber and carrying out a cleaning operation on the interior surfaces of the plenum chamber.