Food warming arrangement

Abstract

Food warming arrangement with a housing (1) having at least one receiving space (2) for at least one food container and with a radiant heating device (6) arranged below a base (5) of the receiving space (2), characterized in that the radiant heating device (6) has at least one rod-shaped radiant heating element (7) which is arranged in an associated reflector (8).

Description

[0001] The invention relates to a food heating arrangement with a housing having at least one receiving space for at least one food container and with a radiant heating device arranged below a floor of the receiving space.

[0002] The food warming arrangement is intended in particular in gastronomic establishments, commercial kitchens, food serving areas, catering or the like for keeping food warm which is contained in suitable food containers.

[0003] The food containers are preferably Gastronorm containers, which are also subject to the EN 631-1:1993 standard. Starting with a rectangular base dimension of 325 mm x 530 mm, also referred to as 1 / 1, smaller container dimensions are achieved by dividing the containers along the width and / or length. For example, containers with a length of 530 mm and a width of 162 mm are referred to as 2 / 4 containers, which can be used side by side instead of a 1 / 1 Gastronorm container. With a central division along the width, however, a corresponding space can be filled with two 1 / 2 containers.

[0004] The present invention relates in particular to a food warming arrangement with at least one receiving space for a 1 / 1 Gastronorm container, wherein—as previously explained—several smaller containers can then also be supported on the edge of the receiving space. Reference is made to the standardization and the known Gastronorm containers.

[0005] Gastronorm containers are available not only with different base sizes but also with different depths. A large depth is particularly advantageous when serving large quantities of side dishes such as mashed potatoes, vegetables, and the like, allowing for a large storage capacity. However, if certain products need to be removed individually and cannot be stacked, relatively shallow Gastronorm containers are particularly useful. The depth ranges from 20 mm to 200 mm.

[0006] There are various approaches to keeping Gastronorm containers warm for food distribution, portioning, or similar purposes. In principle, the Gastronorm containers can be placed in a water bath, but the fill level must then be adjusted to the depth of the Gastronorm containers and prevent them from floating. Furthermore, the water temperature must also be precisely adjusted.

[0007] Another approach also uses water, but the water is evaporated by applying heat and then condenses on the outer surface of the Gastronorm containers, thus heating them. This has the advantage that even containers of different heights can be kept warm without any special adaptations. A corresponding food warming arrangement is known, for example, from DE 299 18 672 U1.

[0008] However, the use of water as a heat transfer medium results in a relatively high risk of accidents and injuries, as well as a high overall weight. Complex sealing is required to prevent steam from escaping and humidifying and heating the surrounding area. When transporting the food warming system, the water should be drained off. Furthermore, heating the water during commissioning is significantly delayed.

[0009] DE 24 42 852 A1 discloses another food warming arrangement for keeping food containers, such as Gastronorm containers, warm for serving hot food. Heating elements are arranged in a corresponding receiving space at a short distance from the food container. This results in the disadvantage that the described arrangement is only suitable for a certain size of food container. When such a food container is removed, the heating elements are completely exposed, which can result in a very high risk of injury and damage.

[0010] In order to keep food containers of varying depths warm or heat them as efficiently as possible, height-adjustable heating devices are known from DE 197 57 004 A1 and the generic EP 0 635 225 B2, which can also be designed as radiant heating devices. For the height adjustment of the heating device, either slide-in rails of different heights or a special lifting arrangement can be provided, resulting in a comparatively complex structure. Conversion is therefore necessary for each container, and incorrect operation cannot be ruled out. If slide-in rails are provided for the height adjustment, they can become dirty relatively easily, which is a major disadvantage, especially when handling food.

[0011] According to the aforementioned DE 197 57 004 A1, a wide variety of heating devices can be provided, including a ceramic hob with a radiant heater. This is essentially a conventional ceramic hob, with a power output of 3.5 kW for a 1 / 1 Gastronorm container.

[0012] According to EP 0 635 225 B2, a radiant heating device in the form of a heating plate is known, which is arranged beneath a base made of glass ceramic. The long-wave radiation emitted by the heating plate thus formed enables direct heat transfer to the food container arranged above it. For the desired heat transfer, close contact should be provided, although a small air gap may be useful to prevent the food from burning in the food container.

[0013] Based on the known prior art, the present invention is based on the object of making the handling of the food heating arrangement particularly efficient and simple.

[0014] The subject of the invention and the solution to the problem is a food heating arrangement according to patent claim 1.

[0015] Starting from a generic food heating arrangement according to the preamble of patent claim 1, it is therefore provided that the radiant heating device has at least one rod-shaped radiant heating element which is arranged in an associated reflector.

[0016] While in the known heating plates based on thermal radiation a considerable heat transfer always occurs by direct heat conduction or convection, in the context of the invention the proportion of energy transferred purely by thermal radiation is maximized, whereby the infrared radiation generated by the rod-shaped radiant heating element is also bundled or directed by the reflector.

[0017] The radiation emanating from the at least one rod-shaped radiant heating element has a pronounced preferred direction essentially perpendicular into the receiving space, so that even large distances and free spaces can be easily bridged.

[0018] The invention enables particularly efficient warming of both deep and shallow food containers without the need for complex adaptation and / or modification. Users don't have to worry at all about whether a familiar range of food containers of different heights can be used.

[0019] Against this background, a preferred development of the invention provides that the base is arranged at a fixed height below an upper edge of the receiving space in the housing. Particularly preferably, a single, non-adjustable height position is provided, resulting in a particularly simple structure.

[0020] In particular, no adjustment with a lifting mechanism or rails, which are exposed to the risk of contamination, is necessary. The inner walls of the receiving space can therefore be smooth. Even if small portions of the heat radiation initially hit the inner walls of a flat container, this heat radiation can be reflected by the inner walls - depending on the design and quality of the surface - and directed to the food container. If, on the other hand, rails, slide-in strips, grooves, or the like were present on the inner walls according to the prior art, the heat radiation would be reflected and / or deflected there, whereby this portion can then no longer contribute to ineffective heating of at least one of the accommodated food containers.

[0021] Even if, according to the described preferred embodiment of the invention, the floor is arranged at a fixed, non-adjustable single height position, it can in principle also be removed for cleaning purposes. The accommodation space with a smooth floor and smooth interior walls also offers the advantage of easy cleaning, preventing contamination and thus achieving the highest hygienic standards.

[0022] It's also advantageous to position the radiant heating system at a fixed height below the floor to ensure proper insulation of the enclosure. These measures also contribute to very high energy efficiency, a simple and maintenance-friendly design, and a compact construction.

[0023] The base is made of a material that is at least largely permeable to thermal radiation, such as glass, ceramic, or glass-ceramic. Suitable glass-ceramic materials are marketed, for example, under the brand name Ceran® by Schott AG.

[0024] The receiving space expediently has a rectangular or substantially rectangular base area, which is particularly intended to accommodate a Gastronorm container, in particular a 1 / 1 Gastronorm container. The height of the receiving space up to the floor is then expediently dimensioned such that even Gastronorm containers with a height of 200 mm can be accommodated. Since the focus of the invention is on heat transfer by radiation and the heat radiation is directed upwards, an additional gap can easily be provided. The depth of the receiving space from an upper edge to the floor can be, for example, between 200 mm and 300 mm, in particular between 210 mm and 280 mm, although other parameters may of course also be expedient for other sizes of food containers.

[0025] Starting from a rectangular base area with a width and a greater length (for example Gastronorm 1 / 1 - see above), preferably at least two and particularly preferably exactly two radiant heating elements running parallel to the width, that is to say along the width and spaced apart from one another in the longitudinal direction, can be provided in each case in an associated reflector.

[0026] Such an arrangement of two radiant heating elements, each with an associated reflector, allows for particularly uniform illumination with thermal radiation with relatively little design effort. If exactly two heating elements are provided in the recording space, they can be arranged along the longitudinal direction, for example, at a distance of 200 mm and 320 mm (measured from center to center).

[0027] As already explained above, the aim of the invention is to maximize heat transfer by radiant heat. Against this background, a preferred development of the invention provides that a free space of at least 4 mm, for example between 5 mm and 15 mm, remains between the at least one rod-shaped radiant heating element and an underside of the floor. Such an air gap prevents direct heat transfer and at least reduces heat transfer by convection. If, according to the previously described embodiment, at least two and particularly preferably exactly two rod-shaped radiant heating elements are present, a corresponding free space is expediently present for each radiant heating element.

[0028] According to a particularly preferred embodiment of the invention, the at least one radiant heating element is formed by a glass tube, in particular a quartz glass tube, and a heating coil or filament accommodated therein. The glass tube is preferably cylindrical and can, in principle, also be provided with a rear-side reflective layer, a shatter guard, or other known devices. Halogen lamps, for example, are suitable.

[0029] The power of the at least one rod-shaped radiant heating element is typically between 300 W and 750 W, whereby the limit values ​​are included and describe only a preferred range.

[0030] If, according to the embodiment specifically described above, two radiant heating elements arranged at a distance from one another are provided for a receiving space, the total power for the corresponding receiving space will be between 600 W and 1,500 W. The specified power values ​​refer to operation at the specified operating voltage, for example, 230 V.

[0031] Within the scope of the invention, it has surprisingly been shown that the specified power, in particular a power of approximately 1,000 W, is sufficient to keep a Gastronorm container of size 1 / 1 warm, whereby, taking into account usual foods, temperatures of over 70° C can also be maintained.

[0032] Compared to existing designs of radiant heating systems for comparable applications, this results in significant energy savings and improved energy efficiency. It is assumed that this is also due to more targeted heating of the Gastronorm containers through the directed radiant heat.

[0033] It should also be taken into account that the stainless steel materials commonly used for Gastronorm containers have a comparatively rough or matte surface on their outer surface opening into the receiving space and have a very high absorption capacity for thermal radiation. The thermal radiation emanating from the radiant heating device according to the invention is therefore initially used for the most part to warm up or keep warm at least one food container, with the remaining free space within the receiving space and the housing subsequently being heated indirectly. Excluding the rod-shaped radiant heating element itself, the highest temperature of the food heating arrangement during operation can thus particularly advantageously be achieved directly at the at least one food container. The housing or the free spaces formed therein can expediently be provided with insulation.Here too, it is particularly advantageous that the radiant heating device is arranged at a fixed location.

[0034] Against this backdrop, it may also be advantageous for the interior walls of the storage compartment to reflect infrared radiation relatively well. This can also be achieved through a suitable selection of materials. Aluminum, in particular, has a significantly lower absorption capacity for infrared radiation compared to the chromium-nickel steels typically used for Gastronorm containers. Furthermore, the interior walls of the storage compartment can also be designed to be particularly smooth and / or have a coating or surface finish to increase reflectivity.

[0035] According to a preferred embodiment of the invention, the reflector, or each reflector associated with one of several radiant heating elements, has rising side walls extending from a central section extending below the rod-shaped radiant element. The side walls can be curved, for example, elliptical, radiused, or parabolically in a cross-section perpendicular to the longitudinal extension of the associated radiant heating element.

[0036] According to a preferred embodiment of the invention, however, a comparatively simple shape is provided, wherein the reflector is trapezoidal in cross-section running along the longitudinal direction. Starting from a short base side of the trapezoid as the central section, the legs then extend obliquely upwards.

[0037] According to a particularly simple embodiment of the invention, an isosceles trapezoidal shape is provided, wherein the reflector can have an opening angle of between 270° and 320°, for example, between its two side walls, i.e. legs of the trapezoidal shape.

[0038] The at least one reflector should exhibit the best possible reflectance in the infrared range, and particularly in the near infrared range. The reflectance in the near infrared range is preferably at least 95%, with the near infrared range being the wavelength range between 780 nm and 1,400 nm. To achieve a high reflectance, the reflector can have a coated surface. The surface can, for example, be coated, vapor-deposited, polished, or even provided with a film. Aluminum, for example, aluminum sheet, is particularly suitable as a reflector material; in addition to the surface texture and quality, a high purity of the material can also be advantageous.

[0039] The food warming arrangement according to the invention was previously explained with reference to a receiving space provided, for example, for a Gastronorm container GN 1 / 1. However, the food warming arrangement can easily have multiple receiving spaces. The food warming arrangement can be designed as either stationary or mobile. Precisely due to the comparatively low power of, for example, 1,000 W for reliably keeping a GN 1 / 1 container warm, mobile use in catering is possible using a standard household power connection, typically 230 V. This even applies if the food warming arrangement has two or three receiving spaces operated in parallel.

[0040] Finally, the housing can also support a heat bridge arranged above the at least one receiving space, which then heats the food directly. The use of radiant heating elements is known for such heat bridges or heat portals. However, in complete contrast to the radiant heating device according to the invention, the heating then takes place not within a receiving space, but through a floor of the receiving space and on the usually metallic outer surface of a food container.

[0041] The invention is explained below with reference to a drawing which merely represents an exemplary embodiment.

[0042] They show: Fig. 1 a food heating arrangement according to the invention in a perspective sectional view, Fig. 2A a radiant heating device of the food heating arrangement in a longitudinal section, Fig. 2B is a plan view of the radiant heating device according to the Fig. 2A, Fig. 3A-3C Detailed views of a rod-shaped radiant heating element of the radiant heating device according to Fig. 2A and Fig. 2B.

[0043] The Fig. Figure 1 shows a food warming arrangement with a housing 1 having a plurality of receiving spaces 2 for a food container (not shown). Each of the receiving spaces 2 can, for example, be provided for a Gastronorm container of size 1 / 1, whereby several smaller Gastronorm containers can also be arranged side by side (e.g., 2 / 4) or one behind the other (1 / 2, 1 / 3, 2 / 3, 2 / 8) in the same receiving space.

[0044] Accordingly, the receiving spaces 2 each have a rectangular base area with a width and a greater length, wherein the height of the receiving spaces 2 is selected so that all standard Gastronorm containers up to a height of 200 mm can be accommodated.

[0045] The recording rooms 2 are essentially designed in the same way, so that the further details can be found on the basis of the Fig. 1 sectioned recording space 2 can be explained.

[0046] The receiving space 2 is bordered on three sides by flat interior walls 3, with a flap 4 provided on the front of the housing 1. With the flap 4 open, a food container can also be inserted from the front and / or the receiving space 2 can be cleaned. The flap 4 also has a flat, slightly inclined interior surface. Furthermore, the receiving space 2 is bordered by a floor 5 made of a material permeable to heat radiation, for example, Ceran®.

[0047] Below the floor 5 there is a radiant heating device 6 which, in the illustrated embodiment, has exactly two rod-shaped radiant heating elements 7, each of which is arranged in an associated reflector 8.

[0048] The rod-shaped radiant heating elements 7, described in more detail below, extend in the direction of the width of the receiving space 2, with the heat radiation being directed upwards by the respective associated reflector 8. This results in the advantage that a free space can be bridged within the receiving space 2 up to the outside of the food container (not shown), so that food containers of different heights can also be easily heated or kept warm.

[0049] Since the inner walls 3 and the inside of the front flap 4 have no functional features and are completely smooth, any heat radiation incident there can be at least partially reflected and thus directed to the food container inside. The inner walls 3 and the inside of the flap 4 can optionally be made of a material that reflects heat radiation relatively well and / or have a reflective surface with respect to heat radiation.

[0050] Further details of the radiant heating device 4 can be found in the Fig. 2A and Fig. 2B. The two reflectors 8 of the radiant heating device can be formed together from a single sheet metal element, whereby, for particularly simple production, the reflectors 8 each have a trapezoidal shape with a central section 9 running below the rod-shaped radiant heating element 7 and adjoining rising side walls 10. In the illustrated embodiment, the two reflectors 8 have a symmetrical trapezoidal shape with an opening angle of 310°. The distance between the two rod-shaped radiant heating elements 7 is 260 mm from center to center along the longitudinal direction in the exemplary embodiment, whereby a horizontal sheet metal section 11 with a length of approximately 85 mm remains between the reflectors 8.

[0051] The representation in the Fig. 2A and Fig. 2B are largely true to scale, but ultimately only concern one possible, preferred design.

[0052] The rod-shaped radiant heating elements 7 are designed as halogen heating rods with a glass tube 12 and a heating coil 13 or a filament arranged therein, the details being shown in the Fig. 3A-3C. Also not shown are optional shatter protection and optional rear-side mirroring, for example, a vapor-deposited layer of gold. Connected to the glass tube 12 are end pieces 14, which may be made of ceramic, for example, and from which connecting conductors 15 lead.

[0053] The power of the rod-shaped radiant heating elements 7 is in a range between 300 W and 750 W, for example around 500 W. Preliminary tests have shown that with a total power per receiving space 2 of approximately 1,000 W, Gastronorm containers made of conventional stainless steel can be kept warm particularly effectively, which is also due to the high absorption capacity of the corresponding surfaces, whereby the surfaces of the known food containers made of chrome-nickel steel are usually matt or rough on the outside facing into the receiving space 2.

[0054] According to the present invention, heating of the food containers is to be effected mainly by directed heat radiation, which is why different heights of the food containers can easily be provided.

[0055] Against this background, direct heat transfer and heat transfer by convection should be kept as low as possible. Fig. 2A that the rod-shaped radiant heating elements 7 are completely accommodated in the respective associated reflector 8 and a free space of, for example, between 5 mm and 10 mm remains to the upper edge of the reflector 8 and thus to the floor 5 arranged above it.

[0056] The Fig. 1, only partially shown, can, for example, have three receiving compartments 2. With a power of approximately 1,000 W per receiving compartment 2, operation with a simple 230 V connection is possible even in a mobile design of the food heating arrangement.

[0057] Furthermore, the food heating arrangement can also be combined with a heat bridge (not shown), which is arranged above the receiving spaces 2 and enables direct heating of uncovered food. A corresponding heat bridge is described, for example, in DE 197 57 004 A1. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 299 18 672 U1

[0007] DE 24 42 852 A1

[0009] DE 197 57 004 A1 [0010, 0011, 0057] EP 0 635 225 B2 [0010, 0012]

Claims

[1] Food heating arrangement with a housing (1) having at least one receiving space (2) for at least one food container and with a radiant heating device (6) arranged below a floor (5) of the receiving space (2), characterized by that the radiant heating device (6) has at least one rod-shaped radiant heating element (7) which is arranged in an associated reflector (8). [2] Food heating arrangement according to claim 1, characterized by that the receiving space (2) has a rectangular base area with a width and a greater length, wherein at least two radiant heating elements (7) running parallel to the width and spaced apart from one another in the longitudinal direction are provided in each case in an associated reflector (8). [3] Food heating arrangement according to claim 2, characterized bythat exactly two radiant heating elements (7) are provided for the receiving space (2), which are arranged along the longitudinal direction at a distance of between 200 mm and 320 mm. [4] Food heating arrangement according to one of claims 1 to 3, characterized by that the base (5) is made of a material permeable to thermal radiation selected from the group consisting of glass, ceramic and glass ceramic. [5] Food heating arrangement according to one of claims 1 to 4, characterized by that the base (5) is arranged in a fixed height position below an upper edge of the receiving space (2) in the housing (1). [6] Food heating arrangement according to one of claims 1 to 5, characterized by that a free space of at least 4 mm remains between the at least one rod-shaped radiant heating element (7) and an underside of the base (5). [7] Food heating arrangement according to one of claims 1 to 6, characterized bythat the at least one radiant heating element (7) is formed by a glass tube (12) and a heating coil (13) accommodated therein. [8] Food heating arrangement according to one of claims 1 to 7, characterized by that the power of the rod-shaped radiant heating element (7) is between 300 W (watts) and 750 W. [9] Food heating arrangement according to one of claims 1 to 8, characterized by that the reflector (8) has rising side walls (10) starting from a central section (9) running below the rod-shaped radiant heating element (7). [10] Food heating arrangement according to claim 9, characterized by that the reflector (8) is trapezoidal in cross-section. [11] Food heating arrangement according to one of claims 1 to 10, characterized by that the at least one reflector (8) has a reflection factor of at least 95% in the near infrared. [12] Food heating arrangement according to one of claims 1 to 11, characterized bythat the housing (1) has at least two receiving spaces (2). [13] Food heating arrangement according to one of claims 1 to 12, characterized by that the housing (1) carries a thermal bridge arranged above the at least one receiving space (2).

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