Patent Publication Number: US-2013239823-A1

Title: Smoking device for smoking foodstuffs

Description:
TECHNICAL FIELD 
     The present invention relates to a smoking device for smoking foods, such as meat, fish and the like. 
     In more detail, the invention relates to a device for cold-smoking foods, i.e. which is suitable for smoking without cooking the foods. 
     PRIOR ART 
     As is known, smoking is a food preserving process which enables aromatising, colouring and conservation of the foods, while at the same time providing an antimicrobial effect, and sometimes modifying the consistency of foods, for example by modifying the protein constituents due to components present in the smoke. 
     Smoking devices are known which comprise a smoking chamber destined for housing the foods to be subjected to smoking and a combustion chamber in which a heat source is arranged, for example a gas or electric burner or a bed of hot wood coals or embers which burns flakes (also called chips) of aromatic wood, such that the fumes produced in the combustion chamber can then be conveyed to the smoking chamber and strike the foods contained therein, aromatising them. 
     Three different types of smoking processes are differentiated on the basis of the process temperature: the first type, known as cold-smoking, is particularly suitable for products which must not be modified, cooked or altered in their constituent properties, such as for example dairy products, sacked products or in any case another suitable food, and is performed at temperatures inside the smoking chamber comprised between 12 and 35° C.; the second type is hot-smoking, in which the temperature inside the smoking chamber is comprised between 50 and 85° C. and in which together with the smoking a cooking of the products is obtained; and a third type of smoking performed at an intermediate temperature (35-50° C.), which is generally performed when it is necessary to activate the endogenous enzymes present in the foods and tenderise the food. 
     Smoking devices for hot-smoking exhibit, as a rule, the combustion chamber made directly internally of smoking chamber with the only detail of dividing the heat source or the naked flame from the overlying zone in which the foods to be smoked are contained, by means of a specially perforated screen which allows only the fumes released by the combustion of the aromatic wood scales to pass. 
     The devices for cold-smoking, on the other hand, exhibit the combustion chamber located externally of the smoking chamber and the chambers communicate through holes made in respective flanks that are destined to match up so as to convey the fumes generated in the combustion chamber into the smoking chamber. 
     As is known, the aesthetic and flavour qualities of the foods treated with heat sources of natural origin, such as for example wood embers, are decidedly superior to those treated with gas burners or electric heaters, as the aroma of the aromatic wood scales adds to the aroma of the wood that has produced the embers, giving the food a considerably more appreciable taste that is closer to the flavours obtained with traditional smoking techniques. 
     However, for the smoking devices using a bed of very hot embers as a heat source for burning the aromatic wood scales, the regulation of the temperature of the smoking chamber is very complicated, and therefore the heat of the fumes, which is, as mentioned, a particularly delicate process parameter, as it has an effect on the state of the product. 
     If there is an excessive raising of the temperature in the smoking chamber due to an excess of the quantity of embers in the combustion chamber, the cold-smoking process can be compromised; on the other hand a too-small quantity of embers leads to having to repeat the smoking process, by topping-up operations to the embers, especially in smoking cycles that involve long times for the food in the smoking chamber. 
     An aim of the present invention is to obviate the above-mentioned drawbacks in the prior art, with a solution that is simple, rational and relatively inexpensive. 
     The aims are attained by the characteristics of the invention as reported in the independent claims. The dependent claims delineate preferred and/or particularly advantageous aspects of the invention. 
     DISCLOSURE OF THE INVENTION 
     In particular, the invention discloses a smoking device for smoking foods, which comprises:
         at least a smoking chamber for containing food to be smoked,   at least a combustion chamber independent of the smoking chamber and provided with at least a heat source for generating a mass of gas for smoking and   conveyor means of the a flow of the smoking gas into the smoking chamber.       

     According to the invention, the conveyor means comprise at least a variable-length conduit suitable for connecting the combustion chamber with the smoking chamber for regulating the temperature of the smoking gases conveyed into the smoking chamber. 
     Thanks to this solution, the temperature internally of the smoking chamber can easily be regulated as a function of the reciprocal distance between the smoking chamber and the combustion chamber, at the same time simply and easily enabling an abundant bed of embers to be used, which will therefore last for a good length of time, without cooking the foods to be cold-smoked. The conduit is advantageously modular and comprises a plurality of tubular sections fitted to one another. 
     In a further advantageous aspect of the invention, the combustion chamber comprises a brazier which is superiorly closed by a removable covering element, the conduit connecting openings realised respectively in the smoking chamber and in the covering element for the passage of the smoking gases from the combustion chamber to the smoking chamber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further characteristics and advantages of the invention will more fully emerge from a reading of the following description provided by way of non-limiting example, with the aid of the figures illustrated in the appended drawings. 
         FIG. 1  is an axonometric view of a smoking device according to the invention, in an open configuration. 
         FIG. 2  is an axonometric view of the smoking device of  FIG. 1 , in a closed configuration. 
         FIG. 3  is a front view of the smoking device of  FIG. 2 . 
         FIG. 4  is a lateral view from the right of  FIG. 3 . 
         FIG. 5  is a plan view from above of  FIG. 3 . 
         FIG. 6  is an axonometric exploded view of a combustion chamber of the smoking device according to the invention. 
         FIG. 7  is a front view of  FIG. 5 . 
         FIG. 8  is a lateral view from the left of  FIG. 7 . 
         FIG. 9  is a plan view from above of  FIG. 7 . 
     
    
    
     BEST WAY OF CARRYING OUT THE INVENTION 
     With particular reference to the figures, reference numeral  10  denotes in its entirety a smoking device for smoking foods such as meat, fish, meats, vegetables, dairy products, or similar food products. 
     The device  10  comprises a smoking chamber  20 , which comprises a support structure, for example made of stainless steel, substantially box-shaped and parallelepiped, which is defined by a base wall  21 , substantially quadrangular, rectangular in the example, a top wall  22  which is also rectangular, and three lateral walls, of which a right wall  231 , a left wall  232  and a rear wall  233 , fixed to one another such as to define an internal compartment  24  frontally open and destined to contain the foodstuffs to be smoked. 
     The front wall of the smoking chamber  20 , therefore, defines an access opening which can be—as illustrated in the example—substantially as wide as the entire rear wall  233 . 
     The access opening is destined to be closed by a hatch  234  slidably and/or removably associated to a pair of opposite walls, in the example the top wall  22  and to the base wall  21 , such as to close the internal compartment  24  of the smoking chamber  20 . 
     Some openings  235  (three in number in the figure) can be obtained in proximity of the lower base of the hatch  234 , as well as of the side walls  231 ,  232 . 
     A discharge outlet  220 , for example a through hole, is realised on the top wall  22  and is suitable for conveying the fumes into the atmosphere. 
     The smoking chamber  20  comprises a first valve  221  associated to the top wall  22  and arranged such as to intercept the discharge mouth  220  in order to regulate the amplitude of the passage hole thereof. 
     In practice, the first valve  221  includes a plate hinged to the top wall  22  at a hinging axis perpendicular to the top wall itself and located offset with respect to the discharge outlet  220 . 
     The plate is therefore activatable in rotation between a closed configuration, in which the plate is substantially superimposed on the discharge mouth, totally obstructing it, and at least an open configuration, in which it is dealigned in plan view, passing between the one and the other position through a plurality of intermediate positions in which the discharge mouth  22 , open for the passage of the smoke, has a varying aperture relating to the angular position of the plate. 
     One of the side walls  231 ,  232  (in the figure the right lateral wall  231 ) affords an access mouth  25  at a zone proximal to the base wall  21 , for example a through-hole formed in the right lateral wall. 
     The access mouth  25  can be intercepted by a second valve  250 , located externally of the right lateral wall  231  and comprising a plate hinged to the wall in a completely identical way to the first valve  221  described above. 
     A first plurality of positioning shelves  261  is located on the right lateral wall  231 , which shelves  261  are vertically aligned and equally spaced at a constant pitch. 
     A second plurality of positioning shelves  262  is located on the left lateral wall  232  which shelves  262  are vertically aligned and equally spaced at a constant pitch. 
     In practice, the positioning shelves  261  and  262  exhibit two-by-two shelves facing one another and at same heights. 
     A plurality of grills  30  can be rested on the positioning  261  and  262 , which grills  30  are suitable for restingly supporting the food to be smoked. 
     In the example illustrated each positioning shelf  261 ,  262  comprises a pair of pins fixed to the respective lateral wall  231 ,  232  and aligned horizontally such as to define a substantially horizontal support surface for the grills  30 . 
     Also, food in the smoking chamber  20  can be suspended by hooks, not shown, which can hook to the top wall  22  or to a cross member, ends of which are fixable to the lateral walls  231 ,  232 . 
     The smoke chamber  20  lastly comprises a removable collection tray  27  that can be rested at the bottom of the chamber itself, for example on the inner surface of the base wall  21  or on a suitable support  28 , in the example inverted C-shaped and provided with open areas on the flanks, such as to be arranged beneath the food to be smoked in order to collect any fat or liquids emanating from the food itself. 
     The collection tray  27 , in particular, has a width that is substantially equal to the width in plan view of the internal chamber  24 . 
     The device  10  further comprises a combustion chamber  40  located externally of the smoking chamber  20  and is distinct therefrom and independent thereof. 
     The combustion chamber  40  comprises a brazier  41  in which glowing embers are accommodated, which is provided with lateral ventilation slits  410  for the bed of embers contained therein. 
     The brazier  41  has, for example, a rectangular plan, slightly smaller than the plan dimensions of the internal chamber  24 , so that it can be placed inside it, for example when the device  10  is not in use, in the compartment located below the support  28 . 
     The combustion chamber  40  comprises a covering element  42  substantially shaped as a polyhedral dome open at the base and with a concavity thereof facing downwards. 
     In practice the covering element  42  comprises a front wall  421  and a rear wall  422  of substantially trapezoidal shape and a rectangular right lateral wall  423  (only in relation to the reference orientation in the figure) having a lower height than a left lateral wall  424 , so that the upper wall  420  which closes the top of the covering element  42  is inclined with respect to the horizontal plane (rising from right to left in the figure) when the covering element is resting on the walls  421 - 424 . 
     The covering element  42  has a rectangular plan is substantially complementary to the brazier  41 , such as to support the walls thereof and superiorly close the brazier  41 . 
     A through opening  43  is afforded on the left lateral wall  424 , for example circular and having substantially identical dimensions to the dimensions of the access mouth  25 , from which the fumes created in the combustion chamber  40  can exit. 
     In particular the device  10  comprises a conduit  50  having a variable length and being adjustable, an end of which is destined to be connected to the through-opening  43  and an opposite end thereof being connected to the access mouth  25 , in practice connecting the combustion chamber  40  to the smoke chamber  20  for outflow of gas from the combustion chamber  40  to the smoking chamber. 
     In a preferred embodiment, the conduit  50  is modular and exhibits a plurality of tubular sections  500  each removably fixed at a head, for example by means of internal-external threads fashioned at the ends of each tubular portion  500 . 
     The length of the conduit  50  in this case depends on the number of tubular sections  500  fixed to one another to construct the conduit  50 . 
     The tubular portions  500  can be of the same length or be differently shaped according to requirements. 
     Alternatively, the conduit  50  can be of telescopic type (not shown in the figures), in which the tubular portions  500  are slidingly associated to each other in order to vary the length of the conduit  50  without intervening on the reciprocal fastening systems between the various tubular sections  500 . 
     It is however possible for the conduit  50  to be of a bellows type, or another equivalent type suitable for varying a length thereof according to requirements. 
     Lastly, the device  10  comprises at least a temperature sensor, of a thermometer type, not shown because of known type, suitable for detecting the temperature inside the smoking chamber  20 , which for example is associated to the door  234 . 
     In the light of what is described above, the operation of the smoking device  10  for cold smoking is as follows. 
     Once the smoking chamber  20  is assembled, it is sufficient to place the food inside it, for example by resting it on the grills  30  or hooking it to the above-mentioned hooks. 
     Additionally, the collection tray  27  is positioned below the food to avoid fat from dripping onto the base wall  21 . 
     Hot wood embers are then arranged or prepared in the brazier  41 . For this operation it is not necessary to carefully batch the embers, as the brazier  41  is located externally of the smoking chamber  20  and is distanced therefrom such that the heat unleashed by the embers does not influence the internal heat of the smokig chamber  20 . 
     Once the embers have been prepared in the brazier  41  they are covered with a layer of aromatic wood-flake, e.g. beech and oak in compressed flake form, without additives or adhesives. The compression of the flakes makes the smoke yield of the wood more effective. 
     Then the brazier  41  is covered using the covering element  42  and the through opening  43  is then connected to the access mouth  25  (keeping the second valve  250  open) of the smoking chamber  20  through the conduit  50 . 
     At this point, the smoke produced in the combustion chamber  40  flows into the smoking chamber  20  and strikes the foodstuffs, flavouring them. 
     By varying the opening of the discharge outlet  220  using the first valve  221  is possible to adjust the air draught according to requirements. 
     By means of the thermometer is then possible to monitor the temperature that develops internally of the smoking chamber  20  due to the passage of the fumes, so as to check that it does not exceed 35° C. 
     In the event it becomes necessary to adjust the temperature inside the smoking chamber, regardless of the amount and heat of the coals in the combustion chamber  40 , the conduit  50  can be acted on, i.e. the conduit  50  can be lengthened or shortened, for example by increasing or decreasing the number of tubular sections  500  that make it up, so as to lengthen or shorten the path travelled by the fumes and, therefore respectively cool them or to maintain the temperature of the fumes higher. 
     In practice, the heat that develops in the smoking chamber  20  is dependent only on the heat of the fumes which pass through it and not on the heat which develops inside the combustion chamber  40  or on the heat which is transmitted by conduction between the combustion chamber  40  and the smoking chamber  20 . 
     Advantageously, with a few simple operations it is possible to use the same device  10  for hot smoking processes, or as a barbecue for cooking food. 
     For instance, by positioning the brazier  41  full of hot coals, i.e., without the covering element  42 , on the bottom of the smoking chamber  20 , for example below the support  28  and the collection tray  27  above the same support, and closing the smoking chamber  20  with the hatch  234 , a device is obtained that is suitable for hot-smoking, as the temperatures that develop internally of the smoking chamber  20  are decidedly greater than those prevoiusly described due to the presence of the brazier  41  directly internally of the internal chamber  24  of the smoking chamber. 
     To use the device  10  as barbecue, it is sufficient to remove the hatch  234 , the collection tank  27  and the support  28 , leaving the brazier  41  on the bottom of the smoking chamber  20  and therefore directly below the grills  30 . The invention as it is conceived herein is susceptible to numerous modifications and variants, all falling within the scope of the inventive concept. 
     Further, all details can be replaced with other technically equivalent elements. 
     In practice the materials used, as well as the forms and dimensions, may be any according to requirements without thereby abandoning the protective scope of the appended claims.