HEATING DEVICE HAVING A RADIANT TUBE

Abstract: Heating device having a radiant tube comprising a burner part (1), in which a stream of heated gas is generated, and a radiant tube (2) comprising a tube system. In order to make it easier to mount a tube system of this kind having a considerable length, it is proposed to provide a separate bearing section (12), which is suspended in order to fasten the tube system. Parts of a hood-like reflector (18) which are of modular design are then attached to this bearing section (12). The tube system, which is likewise of modular design, is then attached. The modular parts are always fastened in such a manner that one end thereof is inserted in the free end of the previous module while the other end is fastened to the bearing section (12).

Description: Heating device having a radiant tube. The present invention relates to a heating device having a radiant tube, comprising a burner part for generating a stream of heated gas therein and a radiant tube comprising a tube system for receiving and conveying this stream of heated gas, which tube system comprises a number of tube parts which are placed inside one another as well as suspension means. A heating device of this kind is well-known in the prior art. Radiant tubes are used in particular where large amounts of air may be displaced and, irrespective of this, a certain degree of comfort needs to be provided. Radiant tubes are suspended above the users. The tube system which is used in this case may be of a considerable length. By way of example, a length of 50 metres may be mentioned. At least two problems are associated with this considerable length. Firstly, it makes fitting considerably more difficult. This problem is solved in practice by the tube system being constructed in the factory from a number of components (optionally provided with a reflector hood) , being disassembled and being assembled again at the premises of the purchaser by a specialist assembly team provided by the vendor. It will be understood that this is relatively expensive. Moreover, it has been found that during operation, and particularly in the cooling-down period, undesired noise, which is caused by the contraction of various parts having different coefficients of expansion, is produced by the radiant tube. This is of minor importance when used in factories and the like, but is not acceptable when used in relatively quiet areas, such as department stores and sports centres. The object of the present invention is to make it easier to produce and fit a heating device of the abovementioned type while avoiding creaking, tapping and other noises as far as possible during the heating-up and cooling-down phase of the heating device. This object is achieved in a heating device of the type described above by the fact that the suspension means comprise a bearing section which is to be fitted separately from the tube parts and is provided at fixed intervals with first fastening means, that the tube parts comprise lengths which substantially correspond to an integer multiple of the interval between the first fastening means, and that the tube parts are provided on either side with coupling means for connection to the adjoining tube parts and are provided on only one side with second fastening means designed to interact with the first fastening means. The invention is based on the insight that, initially, a relatively robust bearing section of limited dimensions should be fastened to the structure of the building or the like in which the heating device is to be arranged. The other parts of the radiant tube having modular lengths are then fastened to the bearing section. This fastening is such that each module at one end engages in a preceding module and the other end is fastened to the bearing section. This manner of assembly is particularly simple. As a result, it is no longer necessary to send a separate specialist assembly team to the purchaser. Provided the instructions are clear, the purchaser can assemble the structure himself. By using modules, it is possible to work with comparatively short lengths, as a result of which the modules are easier to handle and there is less risk of them being damaged. It is no longer necessary, as in the prior art, to move lengths of up to 6 metres using fork-lift trucks. The various parts can be installed manually. The modular design described above can likewise be used for a reflector which can optionally be positioned between the tube parts and the bearing section. By applying the invention, there is no longer any problem in using heating devices having radiant tubes of very great lengths. As a result, a single burner will suffice. This means that only one supply line for gas, for example, is required, and only one cont ol device and one roof opening for the discharge of combustion gas (possibly combined with the supply of fresh air for combustion) are required. The tube system of the radiant tube preferably comprises two tube parts which are arranged parallel to one another and are connected to one another at the end which is remote from the burner. Due to the temperature profile, the tube part which is connected to the burner will radiate relatively strongly in the region of the burner and the return tube will emit a comparatively low radiation. Further towards the end of the radiant tube, the temperature of the two tubes will become more equal, as a result of which the radiation likewise becomes more equal. However, an essentially uniform radiation is obtained over the entire length. The gases emerging from the radiant tube may either be discharged or may in part be fed back to the burner. In the latter case, it is possible to limit harmful emissions. According to an advantageous embodiment of the above-described structure having two tube parts connected parallel to one another, these tube parts are connected to one another and this connection is coupled to the second fastening means. In order not to expose the first tube part which is connected to the burner to all of the considerable heat emanating from the burner, it is proposed to provide this part with a heat-insulating lining. The reflector may be made of a relatively thin material. A hood-like structure ensures that this reflector has a degree of rigidity, it being pointed out that the strength is important only in the region of the ends where connection is made to the bearing section and to a subsequent reflector. Reinforcements may be present in this region. The invention will be explained in more detail below, with reference to an exemplary embodiment depicted in the drawing, in which: Fig. 1 diagrammatically shows a heating device according to the invention fastened in a space which is to be heated; Fig. 2 shows the burner part of the heating device according to the invention, cut away and partially in cross-section; Fig. 3 shows an exploded view of the various components of a module of the tube system and the reflector; Fig. 4 shows the parts according to Fig. 3 in the assembled state; and Fig. 5 shows a cross-section of the connection between various modules. Fig. 1 shows a heating device according to the invention, comprising a burner part 1 and a radiant tube 2. Burner part 1 is provided with a flue-gas discharge and air supply 3. as well as a gas line . Radiant tube 2 comprises straight modules 5. corner pieces 6 and an end piece 7- As can be seen from Fig. 1, end piece 7 is provided with a reversing loop 38. By using a reversing loop 38 of this kind which is simple to construct, the turbulence of the gases within the tube system, and therefore the emission of heat, are promoted. Tubes 36, 37 are situated in the modules 5, 6. Tube 36 is connected to the burner and is connected, via reversing loop 38, to the other tube 37. The end of tube 37 is connected to the flue-gas discharge 3, it being possible for some of the flue gas to be diverted to the burner, as can be seen from Fig. 2. Fig. 2 shows a cut-away view of the burner part 1, partially in section. The burner part comprises a number of diagrammatically depicted components which together form the cladding. A burner 8 is placed inside the latter. This burner 8 essentially corresponds with those of the prior art and will therefore be discussed only briefly. Burner 8 is provided with a gas inlet 9, which is connected to gas line k . The inlet for primary air is denoted by 10. The supply of secondary air, i.e. air containing combustion gas which has passed through the radiant tube and has been mixed with combustion products from the burner, is denoted by 11. By supplying secondary air of this kind, it is possible to limit harmful emissions. A diagrammatically depicted fan, which preferably operates on the discharge side, so that underpressure constantly prevails in the tube system, is present in the burner part, as a result of which slight leakages will never result in gases emerging into the space to be heated. Burner 1 is provided with a fastening plate 4l, which is fastened to bearing section 12. The structure of this bearing section 12 will be discussed with reference to Figs. 3 and 4. It can be seen from these Figures 3 and 4 that the fastening section 12 comprises bearing section parts 13, 14. These are of essentially U-shaped design and are arranged staggered with respect to one another. They may have a length of, for example, 2 metres. When connecting a subsequent bearing-section part, a coupling piece 1 which is likewise U-shaped is used. A free span of at least 4 metres can be achieved using this structure. The bearing section 12 is fastened to the building with the aid of S-shaped hooks 16, which on the one hand engage in openings at the top of the two assembled bearing sections 12, 13 and, on the other hand, in transverse openings 35, which are arranged at regular intervals in the bearing-section parts 13, 14. A chain 17 or suspension rod, for example, which is fastened in a manner not depicted in more detail to the building to be heated, may be fastened to hook 16. It can be seen from Figs. 3 and 4 that the radiant tube comprises tube parts and a reflector. The reflector is denoted overall by 18 and comprises an outer hood 19, on which a U-shaped centering section 21 is arranged. An insulation 22 is arranged inside the outer hood and inside this insulation is situated the actual reflector part 23, which may be made, for example, of aluminium. At the ends, the reflector is provided with reinforcements 20 and 2k (cf. also Fig. 5). Owing to these reinforcements, the reflector may be made of a relatively light material. As a result, it is possible for a length of, for example, 2 metres to weigh only approximately 35 kilos. Such a weight can easily be handled during fitting and no separate hoisting or lifting installations are required. Reinforcement part 20 is provided with openings 39, while the corresponding reinforcement part 2k is provided with hooks kO engaging in these openings (cf. Fig. 5). Reinforcement 20 is provided with a fastening 26 and a fastening 30. By using these reinforcements, the remainder of the reflector may be of comparatively light construction. The tube system comprises the tube parts 27 and 28 and sleeves 32. These sleeves _2 are provided with grooves for accommodating sealing rings 33 therein. Rings may be slid around the tube parts 27, 28, in order to attach a connection strip 29 thereto. The tube part situated in the region of the burner is provided with a ceramic lining _k, in order as far as possible to prevent the first tube part from overheating. Fig. 5 shows the assembled state of the various modules. It can be seen from this figure that fastening 26, which bears reinforcement 20 and thus reflector part 18, is connected to bearing section 12 by means of a pin 25 which can be pushed through opening 35- The two tube parts 27, 28 are connected to one another in the manner which has been described above by means of connecting part 29, and connecting part 29 is fastened in fastening 30. Movement in the axial direction is made impossible by means of the raised flange of fastening 30, while movements perpendicular to the axial direction are prevented by pins or the like. Sleeve 32 has a length which is such that free movement between the free tube ends is possible when the sleeve is present, in order to absorb contraction and expansion during cooling down and heating up, respectively. The structure described above is assembled as follows. Firstly, the burner part is fitted. Then the bearing section 12 is assembled. Because the latter is relatively easy to handle, it can be suspended in the space to be heated and fastened to the burner part very accurately. The various modules are then constructed. As can be seen from Fig. 5, the right-hand reflector hood is arranged with the free end supported on reinforcement 20 of the left-hand reflector hood. The right- hand reflector hood can then be moved upwards until pin 25 can be inserted in the bearing section. The same action is carried out with the tubes. The tube sleeve is arranged in the right-hand tube parts and is pushed into the left-hand tube parts. The right-hand tube parts, and more particularly the connecting part 29 thereof, are then fastened to fastening 30. It can be seen from the above that the heating device according to the invention can be obtained by a number of particularly simple steps. By arranging the openings 35 in bearing section 12 at a discrete interval from one another, incorrect assembly is impossible. Moreover, the various parts are likewise designed such that incorrect fitting of this kind is prevented as far as possible. After fitting the bearing section, the structure described above can be mounted without additional equipment by anyone with a degree of technical knowledge. Owing to the relatively short lengths of the tube parts and the reflector, and the ability of the various parts to move with respect to one another, no noise, such as tapping, is caused by the parts heating up or cooling down.

Claims: CLAIMS 1. Heating device having a radiant tube, comprising a burner part (1) for generating a stream of heated gas therein and a radiant tube (2) comprising a tube system for receiving and conveying this stream of heated gas, which tube system comprises a number of tube parts (27, 28) which are placed inside one another as well as suspension means, characterized in that the suspension means comprise a bearing section (12) which is to be fitted separately from the tube parts and is provided at fixed intervals with first fastening means (35), in that the tube parts comprise lengths which essentially correspond to an integer multiple of the interval between the first fastening means, and in that the tube parts are provided on either side with coupling means for connection to the adjoining tube parts and are provided on only one side with second fastening means designed to interact with the first fastening means. 2. Heating device according to Claim 1, wherein a hood-liked reflector (18) is arranged between the bearing section and the tube parts and having a length which essentially corresponds to an integer multiple of the interval between the first fastening means, and the reflector being provided on either side with coupling means for connection to an adjoining reflector and being provided only on one side with third fastening means designed to interact with the first fastening means. 3- Device according to Claim 2, wherein the reflector weighs less than approximately 75 kilos and having a length which is less than approximately k metres. k . Device according to one of the preceding claims, wherein the tube system comprises two tubes (36, 37) which are arranged parallel to one another, are composed of tube parts and are connected to one another at the end remote from the burner. 5- Device according to Claim k , wherein two adjacent tube parts of different tubes are connected to one another and the connection (29) comprising the second fastening means. 6. Device according to Claim k or 5. wherein the free of the tube which is not coupled to the burner emerges in a chamber which is connected to the inlet of the burner. 7. Device according to one of the preceding claims, wherein the tube part which is connected to the burner is provided with a heat- insulating lining (30 in the vicinity of said burner. 8. Device according to one of the preceding claims in combination with Claim 2, wherein the reflector is provided with a reinforcement (20, 2k ) in the region of the ends.

Inventors: DIJKSTRA KLAAS SJOERD, STAVENGA ALBERT MENKO, VAN HEUR RUDOLF JOHANNES HUBER, VAN YREN OKKO DIRK, DIJKSTRA, KLAAS, SJOERD, STAVENGA, ALBERT, MENKO, VAN HEUR, RUDOLF, JOHANNES, HUBERT, GERARDUS, VAN YREN, OKKO, DIRK
Applicants: DIJKSTRA KLAAS SJOERD, HEUR RUDOLF JOHANNES HUBERT GE, MARK B V, STAVENGA ALBERT MENKO, YREN OKKO DIRK VAN, DIJKSTRA, KLAAS, SJOERD, MARK B.V., STAVENGA, ALBERT, MENKO, VAN HEUR, RUDOLF, JOHANNES, HUBERT, GERARDUS, VAN YREN, OKKO, DIRK
Application year: 1996
Main classification: F24D5
IPC codes: F24D5