Device for keeping food in a cold environment

A device for maintaining a layer of cooled air over a work area, comprising a zone for processing, presentation or laying out food, said zone having an upper surface, a lower surface, a front edge where a user is optionally positioned, and lateral edges, said zone being upwardly open and in contact on its upper and lower surfaces with a layer of cooled air, a means for generating a flow of cooled air to create a layer of cooled air, an air flow channeling circuit comprising a flow delivery opening above the zone, a recovery opening to capture the air flow passing over the zone, and a flow circulation conduit connecting the delivery and recovery openings, the flow circulation conduit passing below the lower surface of the zone, wherein the air flow delivery and recovery openings are disposed laterally so that the air flow circulates between the openings, and wherein the air flow circulation conduit has a substantially horizontal section delimited on its upper part by the lower surface of the zone and is attached laterally to two elbows for reorientation of the air flow, one of said elbows terminating at the delivery opening and the other of said elbows terminating at the recovery opening, both elbows situated substantially at the same height above the opposite lateral extremities of the zone, and wherein the zone has a work surface bordered by a removable strip for holding accessories.

The present invention relates to a device for maintaining a layer of air
 (or more generally gas) at a cool, and preferably substantially constant
 temperature the air lying over a work surface or equivalent to be used for
 various preparations necessitating a particular temperature and preferably
 filtering of the ambient air.
 Preparations, such as culinary preparations, usually take place on inert
 working surfaces. Temperature controls and filtering of the air are
 therefore needed for the whole of the area covering the working surface,
 which necessitates fixed technical means having demanding energy
 requirements. Moreover the temperatures required for some products, in
 order not to break the cold chain in certain fields of activity, such as
 the farm produce industry, is incompatible with work legislation, for
 example meat which is worked while stationary for prolonged periods of
 time, and the interior of which must be maintained at a temperature of
 +3.degree. C., whilst the area itself is at an ambient temperature of 10
 to 12.degree. C.
 The device according to the invention permits these disadvantages to be
 remedied by maintaining the various preparations or foods present on the
 "working surface" at a temperature determined by regulations.
 In the prior art there are however, such devices for the working,
 presentation or laying out of edible food comprising:
 a zone for the work, presentation or laying out of the said food, having an
 upper surface and a lower surface, such area often being upwardly open, on
 its upper face, where it is in contact with a cool layer of gas, such as
 air,
 and cooling means, to cool this layer of gaseous fluid to a temperature
 lower than the local ambient temperature.
 Problems nevertheless remain, linked notably to the relative complexity of
 these devices, their cost and the manner in which the cooling or the
 maintenance of a cool temperature is assured. In this regard, the efficacy
 of the existing devices is open to doubt at least when it is not a
 question of large store-rooms which are more similar to refrigerators open
 at the front rather than to devices for presentation or working of
 foodstuffs, in the manner of stands or tables, as in the invention.
 Also, to resolve the above-described problems of cost, high consumption of
 energy for cooling, and the efficacy with which the required temperatures
 is maintained in the immediate proximity of the zone where the foods are
 laid out, it is proposed in the invention that the said area, called "the
 work, presentation or laying out area" of these foods should be further
 (directly) in contact on its lower surface with a layer of the said
 gaseous fluid, substantially at the said cool temperature. The work,
 presentation and/or the laying out of the foods will therefore be carried
 out in ambient air different from that of the local area.
 The production of the necessary cooling is thus essentially limited to the
 volume of air lying over the working surface of the device. The gas
 (usually air) can be diffused by heat loss forced ventilation or recycled
 cold air. The air thus diffused can be filtered.
 Refrigerating equipment and, preferably, horizontal cooling diffusers allow
 the food to be maintained in the interior of a mass of cooled air, being
 thermally separated from the ambient conditions of the area. For greater
 convenience, the user of the device will be positioned facing the working
 surface.
 Still, in order to maintain the food at a cool temperature effectively, the
 device of the invention will advantageously comprise, to create the said
 layers of cool gaseous fluid (air):
 flow generator means,
 a flow-channelling circuit comprising a flow delivery opening above the
 said zone of work, presentation, or laying out of the foods, an opening
 for recovery of the flow diffused onto this zone, and a flow circulation
 conduit linking the distribution and recovery openings, this conduit
 passing at least under the main part and in contact with the lower surface
 of the said zone of work, presentation or laying out of the foods,
 and (preferably) a site reserved in the flow-channelling circuit of the
 flow, to receive uniquely a part of the said flow generator means.
 Always with a view to the good conservation of the foods and to the
 performance of the installation in relation to its cost, a complementary
 characteristic of the invention envisages that advantageously the
 above-mentioned flow circulation conduit has a (substantially) horizontal
 section defined on the upper part by the lower surface of the said area of
 work, presentation or laying out of the food and attached laterally to two
 elbows each approximately at 180 degrees, for reorientation of the flow,
 these two elbows terminating, one at the distribution opening, the other
 at the recovery opening, the two openings each being situated
 approximately at the same height above two opposite ends of the said area.
 Concerning this zone, two possible embodiments have more particularly been
 envisaged:
 the first envisages that the said zone has a working surface bordered on at
 least one side by a removable strip for carrying accessories limited
 frontally and above by a substantially vertical panel (for example a glass
 pane), the strip communicating on its lower face with the cool environment
 flow circulation conduit.
 the second envisages that this zone can be essentially in the form of a
 succession of trays placed one beside the other and in contact, above and
 below, with the said cooled gas flow, this succession of trays being
 itself bordered by the above-mentioned strip with the front panel and
 having the same direct communication, on its lower face, with the cooled
 fluid circulation conduit.
 It is to be noted that the preceding characteristics are well able to meet
 the hygiene conditions imposed or anticipated.
 In this regard, a complementary characteristic of the invention anticipates
 that the said zone of work, presentation or laying out of the foods will
 be bordered by a support frame supported by the above-mentioned elbows or
 the limiting lateral walls of the conduit and on which can rest
 peripherally the working surface or the trays.
 As far as hygiene is concerned, it is proposed that the bottom of the flow
 circulation conduit includes a waste outlet opening into a removable
 recovery tray. Moreover, in order to improve the performance of the
 installation, the circulation or the renewing of the air in this
 environment of the zone of work, presentation or laying out of the foods,
 once again, just like the hygiene of the entirety of the device, a
 complementary characteristic of the invention anticipates that
 advantageously:
 the inlets for distribution and recovery inlets of air (gas) will have
 substantially horizontal strips to channel the flow, in order to ensure a
 preferably substantially laminar flow between them, in contact with the
 above-mentioned elbows which will then be advantageously rounded, and
 above all:
 the recovery opening will have a filter for the said flow, carried by a
 removable frame on the corresponding elbow, as well as indirect heat
 exchange means between the recovered gas flow and a cool fluid,
 and the circulation conduit will have a fan situated preferably in
 proximity to the elbow where the recovery opening is situated.
 Correspondingly, the flow generator means will comprise, as well as the
 above-mentioned fan, a drive motor for this fan, with, as a distinctive
 feature, the fact that the fan will be placed in the conduit, in proximity
 to the elbow where the recovery opening is situated, whilst the motor will
 for preference be isolated from the flow channelling circuit.
 In a comparable manner, it is moreover recommended that the cold generation
 unit associated with the above-mentioned heat exchange means should be
 installed away from the flow channelling circuit and that it should be
 isolated from it by a separation wall only traversed by pipes. It will be
 advantageously the same with the fan drive motor mentioned hereinabove,
 only the linking cables between them then traversing the said separation
 wall.
 According to another characteristic of the invention, the preceding device
 will not have a fixed location. It will thus be considered as movable
 equipment.
 In this regard, in order to allow its movement, it is anticipated that it
 will be formed as a table or a stand, comprising then not only the device
 according to any of the characteristics described hereinabove, but equally
 support legs on which the devices will rest, the base in question being
 adjustable in height and/or being mounted on castors.
 According to particular embodiments, all or part of the following
 characteristics will moreover be able to be retained:
 the flow cooling system can be of the thermo-siphon type with a motorised
 unit or any other means according to the energy source available,
 the production of cold is assured by means of a calorific fluid free of
 "CFC" gas,
 the cooling can be either lateral or frontal
 the cooling may be static or by forced ventilation,
 the cooling can comprise a dust filtering system,
 the working surface can be equipped with a removable support for various
 uses,
 the working surface can be equipped with a waste drainage pipe,
 the working surface can be removable,
 the working surface can be composed of several sections,
 the working surface can be composed of removable accessories and contents,
 the working surface can be composed of different materials,
 the working surface can be lined with smooth removable sheets on an
 underlying base,
 the working surface can be bordered with a glass panel(s),
 the working surface can include lighting,
 the working surface can rest on sections with rounded grooves,
 the diffusion tank (formerly called "flow circulation conduit") can be
 composed of sections supporting the working surface,
 the diffusion tank can be equipped with a removable drawer,
 the diffusion tank can be equipped with a draining conduit,
 the diffusion tank can be equipped with a removable waste receptacle,
 the diffusion tank can be equipped with a waste guide,
 the casing of the device can serve as a diffusion tank,
 the casing can assume different forms, rounded and/or angular,
 the rounded casing can act locally as a deflector,
 the casing can act as a retention tank (of condensates in particular),
 the casing can act as a draining tank,
 the casing can act as a support for the different parts of the device,
 the diffusers (formerly called "openings") can be other than of metal,
 the diffusers can be composed of guiding strips,
 the diffusers can be equipped with removable filters,
 the removable filters can be of metal,
 switching on is executed by means of a control equipped with means for
 switching off,
 the refrigerating equipment (or cold preservation unit) is lodged under the
 working surface and under the air circulation conduit,
 the refrigerating equipment can be made removable for maintenance,
 the refrigerating equipment can be lodged on telescopic runners,
 the evaporators and filters can include condensation trays,
 the condensation trays can be removable,
 the refrigerator unit casing can have ventilation grilles,
 the ventilation grilles of the casing can be disposed laterally,
 the electrical controls can be equipped with a voltage indication,
 the electrical controls can be equipped with a temperature indicator,
 the refrigerator circuits are exterior to the diffusion tank.

With reference to these drawings, the device comprises an air recovery
 recycling or regeneration (or simply extraction) opening la equipped with
 a diffuser 4 a grille (preferably with horizontal strips) and with a
 filter 5 carried by a removable frame and facing a heat exchange unit 6
 traversed by a flow of air 1. This air is driven by a fan 2 and guided
 insulated from the fan motor 2a in a diffusion duct (or conduit) 16
 prolonged laterally by two lateral shaped casing 30a, 30b to be delivered
 to the opening 1b, itself equipped with a diffuser 4 with horizontal
 strips and with an air filter 5. The casings 30a, 30b each define
 internally a hollow elbow "in the shape of a hair pin" communicating with
 the central rectilinear horizontal part 16a of the duct 16 and forming, on
 either side of the working surface 9, respectively an air recovery channel
 3a and an air delivery channel 3b, each channel terminating at one of the
 openings 1a, 1b both situated above the level of the horizontal working
 surface 9. Above the surface 9, the device is open, although limited
 frontally by a wall 20 higher than the surface 9. This working surface 9
 has an upper surface 9a and a lower surface 9b. Its upper surface 9a is
 cooled by the cold air delivered by the channel 3b, whilst its lower face
 is washed by the equally cold air (.apprxeq.3.degree. C.) which circulates
 in 16, since the surface 9 defines the upper surface of the central
 section 16a of the duct 16, between the channels.
 In the embodiment of FIGS. 1,2 and/or 3 or 4, the shaped casings of the
 device support the working surface 9 by means of a frame 27 which is
 supported in particular by the lateral walls 32a, 32b of casings; the
 working surface 9 is provided at 14 with a drainage pipe. This drainage
 pipe projects under the working surface, up to the diffusion shaft 33
 which it traverses in order to communicate with a receptable 15 situated
 underneath (FIG. 3).
 The diffusion shaft drains at 17 into a removable receptacle 18. According
 to a variant not illustrated this drainage may take place into a liquid
 waste reservoir.
 The working surface 9 is bordered by a support strip 19 for one or more
 removable accessories, which is over a longitudinal side of the conduit
 16, on the central section 16a.
 According to a variant not illustrated, the base accepts a series of
 different accessories such as troughs and different equipment, (knife
 holders and other utensils, electrical equipment holders, indicator
 equipment . . . )
 In FIG. 3, the pane 20 is retractable.
 The feeding of cooling fluid to the indirect heat exchange unit 6 is
 assured by a cold generator 10 lodged at the exterior of the cooling flow
 channelling duct 16, thus away from the circulation circuit of this air,
 as is also elsewhere the motor 2a of the fan 2 (which is itself lodged at
 an end of the section 16a, near the recovery drainage pipe 3a).
 An internal partition 32 moreover isolates the motor 2 with regard to the
 fan 2. This partition is traversed only by the motor/fan unit connector
 shaft 2b and by the links (shown schematically all together at 6a) between
 the heat exchange unit 6 lodged in the drainage pipe 3a with the filter 5
 and the generator unit 10.
 In FIG. 1, the cooling equipment 10 for the generation of cold (about
 3.degree. C.) is lodged below the device and is ventilated by open grilles
 12 in a protection cover. It is mounted on slides 11 and has controls 13
 in its front face.
 Moreover, the whole of the device of the invention is supported by a base
 comprising vertical tubes 21 furnished with pivoting wheels. According to
 a variant illustrated in FIG. 4, the whole of the device of the invention
 can be supported by tubular legs 22 having feet adjustable in height.
 In the two cases, it is thus a question of an assembly with the aspect of a
 table or a stall.
 According to the variant illustrated in FIG. 4, the device of the invention
 can be equipped with one or several removable frames 25,27 carried by the
 framework or the casing of the device and receiving removable trays 26 of
 different forms and materials. It could be the same framework as that used
 to support the working surface 9 (see FIG. 3).
 FIG. 4, the device can receive at 19 retractable supports 28 for a glass
 breath shield 29 or any other accessory.
 A removable stopper 34 seals the drainage pipe of the channel shaft 16.
 As a non-limitative example, the casing of the device of the invention can
 have dimensions of the order of 1400 mm in length, of 800 mm in width and
 1003 mm in height. The working surface 9 can be about 850 mm from the
 ground.
 The device according to the invention is particularly intended for the farm
 produce industries, and for preparations in butchery, charcuterie, the
 fish trade, industrial kitchens and patisserie catering.