DE1041927B - Process for operating tube furnaces and tube furnaces - Google Patents

Description

Method of Operating Tube Furnaces and Tube Furnaces The invention b! relates to tubular furnaces and, in particular, to improved apparatus and. a hated one Methods for more effective and economically safe treatment of flowing reactants in tube furnaces.

In recent years, tube furnaces, in which thin-walled metallic Reaction tubes go through a refractory heating chamber and from the outside through combustion gases heated are widely used, especially in the production of Hydrogen and various olefins from flowing hydrocarbons. You wise but still have various disadvantages. For example, it would be very desirable Achieve one or more of the following improvements: Improved performance per plant unit; Use of high-temperature reactions, which have hitherto been generally accepted are considered outside the field of tube furnace technology; a sharp decrease in the amount of catalyst per unit of power in a catalytic process necessary is; an increased use of. heavy liquids as the starting material; more extensive use of pressures above atmospheric and in particular whether he is half 7 kg / cm2. Achieving such desired results is available, however one or more of the following obstacles, which both when using gaseous as well as liquid fuels occur for heating the current tube furnaces; Difficulty in achieving and regulating the separation in heating while achieving short flame lengths (that is of about 30 cm for gaseous fuels and about 90cm for the heavier liquid ones. Fuels); Lack of appreciation of the benefits short flames and their relationship to physical ones for economical operation major factors; Damage to the pipe metal as a result of the flames striking or extremely hot combustion gases; the alternate harmful destroying and re-forming metal oxide films, on reaction tubes as a result of the occurrence of alternating oxidizing and reducing gas atmospheres and the reduction the strength of such films; the interfering influence of combustion gases from two burners, which favors hot pipe stains; the appearance of spots uild. Deposits on reaction pipes before the combustion gas streams strike from oil-fired burners, partly due to the vanadium content in your oil and ash low melting point; Uneven pipe temperatures at 1800 C on the pipe distant points, which causes permanent pipe deterioration ', Damage to the internal shape of the metal and the structure, rot bubbles and bumps; Difficulty controlling luminous flames; and incorrect application and Regulation of pipe tension.

These disadvantages are overcome by the invention.

The new method of transferring. Heat on vertically arranged Relaction pipes to the metal in the fireproof brick heating chambers of a tubular furnace, especially for the production of hydrogen or olefins from liquid hydrocarbons or of hydrogen by methane reforming is characterized in that in Various levels of altitude flow from hot combustion gas diagonally to the walls the heating chamber are introduced into the chamber, the heating gas flows so long be kept out of contact with the reaction tubes until the combustion of the Heating gas has occurred and so a zone of burned heating gas around the reaction tubes is formed and. with preferably the heating gases spiraling upwards through d.ie Chamber ceiling are removed.

The furnace used to carry out the process has a refractory brick-built heating chamber with onsroh ren made of metal and arranged vertically therein which pass through the heating chamber and at a distance from the chamber wall are arranged, and is characterized by elongated in thicker parts of the chamber walls trained chimneys and heating burners arranged in these chimneys, the chimneys at different heights flat and so arranged in the chamber wall are that the extension of a straight line from the torch nozzle to the end of the inner chimney wall drawn between the reaction tubes and the adjacent chamber wall goes through, with preferably at least one of the burner chimneys an extension angle from 20 to 300. The tubes can advantageously be separated from each other by Center to center have a distance of 11/2 to 21/2 pipe diameter. In general the tubes are attached to a support arranged below the furnace, e.g. B. a quench tank or second oven.

Each reaction tube is attached below the heating chamber and is under upward tension from its anchorage point, which is preferably via spring-loaded hangers arranged above the furnace vault and a support frame as well as a hydraulic, ram evoked. and at least 0.7 kg / cm2 amounts to.

In such a device, the thickness of the part of the results Chamber walls, which contain the burner chimneys, due to the special reaction, for which stove the stove is built and the type of fuel used. It is Desires as much as possible of the combustion envelope from the burners. in the burner chimneys. hold back. When using a burner chimney according to According to the invention, the hot combustion gas flows into the heating chamber and remains aside from direct contact with the pipes, so as to cause partial flames and to prevent the pipe from being damaged as a result of fluctuating conditions to protect. Even when using gas as fuel, it is difficult to persist hold back the entire combustion flame inside a chimney. Using By using oil as fuel, it is impossible to keep the whole flame inside a fireplace withhold of practically permissible length. However, according to the invention at The flame that goes into the heating chamber is directed and regulated for every fuel. With both gas and oil firing, the reaction tubes can therefore be closer to the chamber walls can be arranged, and more reaction tubes can be placed in a chamber of the same size are used than in the oven construlations previously used, thereby increasing the effectiveness and the efficiency of the furnace operation is increased considerably.

The furnace itself is preferably rectangular in its own. outer cross section designed. The internal cross-sectional outline of the heating chamber is preferably either be elliptical, octagonal, or circular.

Thus, the parts of the chamber wall at the furnace shell corners are thicker than the parts in between. In this way, thickened parts can be in economical way on the corners; intended for the arrangement of burner chimneys be, without the need of a furnace wall of the same shape, sufficient Thickness to accommodate adequate burner chimneys. Moreover, as a result the thickness of the corner parts of the construction areas. higher heat absorption capacity which aid the use and performance of the oven.

In a preferred embodiment of the invention, the tubes are from center to center by about 11/2 to 21/2 pipe diameter apart. It became. found that with careful avoidance of disadvantageous exposure to flames at the improved furnace design of the invention for adequate heat transfer can be achieved on the pipes with this relatively tight pipe arrangement. Thus, in a given size chamber, placing the tubes closer together does more Space between the tubes and the chamber walls and also increases the regulated protective flue gas flow. Where this additional protection is unnecessary, it can the chamber size can be reduced accordingly.

According to another preferred embodiment of the invention the reaction pipes below the furnace hearth on supporting parts, the pipe, a quenching tank, anchored a second furnace or other treatment equipment, and tension is exerted in the upward direction by means located above the furnace vault. Such means can be regulated manually or automatically -to the desired Applying the amount of stress on the pipes and thus the use of higher temperatures to allow which in turn the highest effectiveness with the metals used bring about. Thus where a tensile strength of 900 kg was applied in previous constructions was, with the pipes hanging up, although it was only necessary, for example to use a 90 kg tension to bind, puff or warp on To bring a minimum, it is possible according to the invention, exactly the desired Exercise amount of tension and thus eliminate undesired temperature restrictions.

According to the new method, a plurality of vertical High currents of hot combustion gases into the heating chamber longitudinally at an angle to the surfaces, through which the currents go out, introduced arranged paths. Guide these ways the flows between the pipes and the adjacent refractory wall and hold them Flows out of contact with the pipe until essentially complete combustion of the gas has taken place, with a protective layer of completely oxidized Get gas around the pipes. remains to a constant oxidizing gas atmosphere to be provided for the pipes. This protective cover thins the in the chamber on the intermediate surfaces, which are formed between the protective cover and the flows, incoming gas flows, and is constantly being renewed from these dilute gases. The combustion gases are essentially parallel on the way between the pipes, the chamber wall and the treasure layer passed through the chamber to the tubes by convection and radiation from the gas and to be heated by radiation from the refractory wall. Preferably the Combustion gases spiral upwards to the outlet at the top of the furnace structure directed. Meanwhile, the outlet channel in the bottom of the stove, in the center of the Chamber or any other desired location because it is the ratio between gas and pipes is what matters, not the location of the drain.

When the furnace is put into operation, there are hot combustion gases introduced into the chamber from the burner chimneys and flow along the chamber wall between the wall and the next pipes. When this gas comes from the burner and starts to burn, reducing conditions are and remain in place, until the complete burn is complete. Then the gas, which is water and depending on the. Firing conditions about 2 per cent and more Contains oxygen, to an oxidizing gas. It is desirable to complete a fa.st To cause combustion in the burner chimneys. In any case, even if complete Combustion has not occurred in the chimney, the directed flow allows along the wall the achievement of complete combustion before the pipe touches. This now oxidizing gas continues upwards or downwards around the chamber wall depending on the elite from the location of the outlet channel, with a part inward to the center of the chamber diffuses and washes around the pipes. As the operation continues, this will wash around the amount of oxidizing gas to flow in the middle of the furnace d; the tubes with a steady oxidizing gas atmosphere. Because the relatively hotter fresh combustion gas from your chimney usually flows at a temperature of about 19,250 C it circumferentially around the outer, part of the chamber. Even if the burn is not yet completely at the mouth of the chimney and reducing conditions, at this point, the tubes are through the oxidizing gas inside the Gas flow protected The inner edge of the gas flowing out of the chimneys and around the The chamber of the circulating gas stream is made more stable by the relatively cooler oxidizing one Gas dilutes and diffuses inwardly into the gas stream from which a Part of the outlet channel emerges together with the other gas.

In a single cell furnace, it is preferred that all of the combustion gas streams flow into the chamber in the same direction. In this way, the get even gas flow, and the flow from each burner closes the current going in one direction. However, this arrangement is not always practical, especially not for multi-cell ovens where it may be desirable from only to heat two sides. In multi-cell ovens, for example, it may be desirable to heat from two sides at each height with a gas flow which is opposite Has direction at any altitude.

While such flow creates turbulence, the flow of gas is turned off each burner completely on its way from the burner chimney to the far side of the The chamber is oxidized and the turbulence is not detrimental.

If desired, it can be oxygenated or enriched in oxygen Air can be used along with the hydrocarbons, to make hotter flames and produce hotter combustion gases. and at the same time a much greater use of heat can be achieved without pipe damage.

The introduction of gas into the chamber along an oblique to the furnace side, from which the gas flows out, arranged path, increases the efficiency considerably of the furnace. Any part of the longer outer wall of the chimneys that extends over the The end of the shorter, inner wall of the chimney extends, forming a highly heated one radiant surface.

In the drawing, FIGS. 1 and 2 are cross-sectional views of the furnace chambers according to the invention, Fig. 3 is an elevation of a device for the exercise of upward tension on the reaction tubes with anchoring the tubes under the. Furnace, Figure 4 is a plan view of the support means for the tubes in an entire cell of a furnace according to the invention, FIGS. 5 and 6 are schematic views of multi-cell furnaces with a schematic burner arrangement.

According to FIG. 1, a single cell furnace 10 has a refractory wall 11. The outer cross-sectional shape of the furnace is rectangular while the inner cross-sectional shape the heating chamber is 12 octagonal. Four from pages 13 of the Outagon showing the Forming sides of the heating chamber 12 are parallel to the hypotenuse of an isosceles right-angled triangle, which includes the right angle, the one outer Corner of the furnace wall. The furnace walls formed by the walls 13 are considerable thicker than those formed by the inflected walls 14 of the octagon. Burner chimneys 15 are formed in these compressing parts, and a burner 16 for flowing Hydrocarbon is arranged in each of the chimneys 15. The inner wall 17 of each of the chimneys is angled in such a way that the extension of a straight line drawn from the burner nozzle to the intersection of wall 17 and surface 13, between the reaction tubes 18 and the wall of the heating chamber 12 passes through. The reaction tubes 18 go straight down through the chamber 12 and are forming from each other of a hollow square at intervals from center to center of. two pipe diameters separated. In the one shown in FIG. Construction are the four burners on the arranged at the same horizontal height. Preferably there are several such height levels used. Although four burners per height level are shown in Fig. 1, one, two, three or four burners per height level can be used if desired.

In operation, the furnace of FIG. 1 is flowing hydrocarbon inserted into the burners 16 and ignited. The combustion gas flows are through the walls of the chimney and in particular wall 17 gelenlçt so that the hot gases between the tubes 18 and the furnace wall holme nach.-part exposure to the flame Pipes through. The gases that diffuse inwards are completely oxidized and heat the tubes 18 by convection and radiation. The refractory furnace walls are heated by the circumferential flow of hot gas from the chimneys and radiate Heat up the pipes. As a result of the oblique. Wall surfaces are the gases from the Burners evenly guided around the tubes on a spiral path. The inside to Formation of the protective layer of completely oxidized gas diffuse; move the gases generally spiral around and between the tubes and wash around the tubes constantly with an oxidizing gas atmosphere. The gases are from a not shown Discharged outlet channel at the top of the chamber and thus move on one ascending path around the pipes. The eight angled inner surfaces bear on the effectiveness of the radiation from the refractory furnace walls on the reaction tubes at. In addition to these eight walls, the parts of the burner chimney walls also provide 18, which extend beyond the end point of the wall 17, also radiation surfaces for heating the tubes 19.

As a result of the inclination of the wall 13 to the axis of the burner chimney step the flows of hot gases out of the chimney between the chamber wall surfaces (13), which are arranged obliquely to the path of the streams.

In Fig. 2 is a single cell oven. 20 shown, which is a refractory Brick wall construction, 21 owns. The external cross-sectional shape of the furnace 20 is rectangular. The inner cross-sectional shape of the heating chamber 22 is circular and forms a steadily curved inner wall 23. Reaction tubes 24 go vertically down through the heating chamber 22 and are one of the under Formation of a hollow. Square separated from center to center by two pipe diameters. Two burner chimneys 25 are at each burner height in the thickened Edeil of the furnace wall formed at the corners of the structure. Burner 26 for flowing hydrocarbon are mounted in the amines 25 and generate hot combustion gases for introduction into chamber 22. In this construction, two burners are on the same level arranged, but all the gas streams coming out of the chimneys flow in the chamber in the same direction. As in the case of the octagonal interior design of Fig. Figure 1 introduces the use of a circular chamber 22 within the rectangular one Oven 20 to verdidcten corner parts for accommodating the burner chimneys 25 and the burner 26.

The operation of the furnace of Figure 2 is the same. that of the furnace according to Fig. 1. The biting combustion gases are between the tubes 24 and the furnace wall 23 passed through the short walls 27 of the burner chimneys and as a result of the circular Outline the chamber in an even more uniform spiral around the tubes and down, to the outlet channel, not shown, which is located at the bottom of the chamber is led. The inner protective layer of oxidizing gas is made in the same way formed by diffusion of the diluted combustion gas inwards. The circular one inner wall of the chamber is a very effective radiating surface, giving radiation on all pipes from all winding surfaces and thus the pipes in a very heated effectively. As in Figure 1, any desired number of burners can be used will. More than two brokers can be placed on each horizontal level if desired to be ordered.

In Fig. 3 elongated reaction tubes 30 are on a fright container from 31 anchored. A. Support flange 32, provided with reinforcement members 33, is around the upper part of the tube formed above the furnace vault. The upper end of the pipe is sealed by means of Blin, dflanschen 34 and 35. The respondents become introduced into the tube through an injection tube 36. Boost voltage is applied to the Pipe exercised by means of hanger 37, which is attached to the support flange 37 at 38 are. and go up through a shoulder 40. The hangers 37 go by compression spring bearings 41 and. are whether he is half of the camp attached by an Älutter 42. The lugs 48 are attached to the supporting U-iron. 43 at 44 by nuts and bolts attached. The U-irons 43 are welded to a support frame 45. Upward pressure will exerted on the support frame 45 at each corner by a hydraulic ram 46, which rests on a support 47. The upward directed by the rams 46 Force Is exerted on the support frame 45 in a uniform manner and thus in a more uniform manner Transferred to the hangers 37 through the U-iron 43. The spring bearings 41 are in order to compensate for individual stresses which result in a particular Pipe can arise during operation, and thus fractures as a result of being too rigid To prevent storage.

By the means shown in Figs. 3 and 4, the desired amount of boosting can be achieved on - the pipes are exercised. Most of the weight of the pipe and the The catalyst inside is supported by the support below the furnace top wear. The hydraulic fluid for the ram 46 can be supplied manually or automatically to induce and maintain the desired tension, which at the in the oven. applied temperatures is necessary.

In Fig. 5, two height levels of a three-row furnace 50 are shown, to explain the location of the burner chimneys Height A is the lower or basic height and height B is the second at which the burner is in any vertical direction Distance from the burners of height = 4, for example from 60 to 90 cm. the Formation of these two height levels alternate until the desired height is reached is.

Fig. 6 shows two levels of a four-cell oven 60., in which the Rows arranged in foani of a square. Height 24 is the base height, and height B is the second height at which the burners and chimneys are perpendicular to those of. High are separated by any distance as in the case of the furnace 5. These elevation levels alternate until the desired height is reached.

When constructing a furnace according to the invention, preferably the wall thickness at the thinnest point is usually not less than 30 to 36 cm be to the desired heat capacity. obtain. By using the preferred octagonal, circular or elliptical inner chamber outline are the Corner parts of the stove thick enough for the formation of burner chimneys of the desired one Length of 90 cm. If desired, arrangements can be made to prevent the impact or Preilpiatten can be provided inside the chimneys to allow for faster greening to achieve.

In a furnace with a single cell as shown in FIGS. 1 and 2, this can Firing from a single surface, from two, from three or from all four oven surfaces. made from. Where two or more adjacent cells form the furnace, as shown in Fig. 5, the firing is effected from two or three sides of the cell, if desired. If four cells are used to form the furnace, as in FIG. 6, then. the Firing advantageously takes place from two surfaces of each cell. However, despite the number of cells or the number of surfaces from which the stove is fired, is always an advantage due to the relative absence of exposure to flames or heating gas, as described, achieved.

While it is necessary that the inner limit of the out of the chimneys emerging gas streams or envelopes do not have the cross-sectional area of any the pipe cuts, touching the furnace wall is immediately at the opening of the Amines desirable to heat the primary radiating surfaces.

The angled or curved surfaces of the furnace act opposite the mouth of the burner chimneys as deflection surfaces and guide the extended ones Ends of the combustion envelopes or streams around the perimeter of the chamber. So where the burners are all clockwise or counterclockwise aligned, the gas will evenly move around the furnace in a parallel direction flock to the walls. This arrangement creates a minimum flow around the individual Pipes around and is preferred. If turbulence is desired, it can be reversed Caused gas flow from burners aligned in opposite directions will. While -the shown burner chimneys essentially horizontal such an arrangement is not essential and the burners may if desired up or down to achieve a desired temperature control to achieve within the chamber. In general, it is desirable that the flare angle of the burner chimney is between 20 and 300, although for special purposes one larger or smaller expansion may be desired. As fuels can also Residues from thermal cracking of oils, asphalt-like bodies and the like are used will.

With regard to the pipe spacing, it is not essential that every pipe is separated from the neighboring pipe by the same distance. Any pipe arrangement you want can be used like those in parallel rows, in the middle of rectangles, in hollow squares or rectangles, or in a single one or in concentric ones Circles. The observation that it is possible to achieve completely satisfactory results Achieving closer spacing of the reaction tubes according to the invention makes it possible the same throughput with a smaller furnace or a larger throughput with a furnace of the usual size but with more tubes.

Where. Upward tension is applied, the hydraulic in Figs. 3 and 4 preferred means shown, with the desired adaptability to the construction is achieved by spring bearings for the individual tubes. Preferably the tension on the reaction tubes is controlled by means of an automatically hydraulic system exerted, which the average stress on a supported Maintains pipe group within reasonably narrow limits. Because the reaction tubes are subject to slow axial creep under stress, it is preferred that the tension is kept to a minimum level which will prevent sanitary napkins and discard. When applying upward voltage to reaction tubes devices for measuring, displaying or recording the voltage are advantageous used by one or more tubes showing the average spring load show, although instruments can also be used to measure the individual tension Measure on each of the pipes and make a quick determination for that particular pipe. A pipe is preferably used in each cell as a control indicator and its tension z. B. recorded by means of an oscilloscope. Preferably Stress is also applied that is sufficient to prevent uneven expansion in the pipe and counteract binding stress against the pipe.

During operation, the pipes can burst due to strong changes in the Stress caused by blows of condensate introduced into the pipes.

In the case of a tube with an upward tension, however, causes it to occur of the same water hammer only the pipe, itself in a normal and almost unstressed Way to contract. When a pipe has warped or just warped begins to show, the tension should-preferably be increased, either by exerting additional tension on the entire scaffold or on each of them Springs supporting pipes. In this way it is possible to apply tension in amounts which lie between just a slight inevitability and go up to amounts, which exceed the short-term yield point of the used metal. For best Results should be applied to the amount of tension, whichever of the particular encountered condition and that can sometimes be as low as 0.7 kg / cm2 can, but is usually well below the stress in pipes downward tension prevails and an expansion in a proportion of about 12 mm per year in a 7.5 m pipe.

When a new furnace is put into operation, in which a step-up voltage is applied to the pipes, it is desirable to adjust the tension temporarily, when the pipes are brought to their normal working temperature. The tension should stabilized at a height not exceeding 3.5 kg / cm2 for a time and then afterwards can be set when the pipe behavior is observed. It is particularly beneficial to recognize the exact stress state of the reaction tubes when using the invention, and it is desirable that the voltage be automatic when operating continuously exerted to a predetermined level or otherwise where a manual regulation is applied Appropriate warning devices should be placed to indicate that the voltage is no longer within the desired range.

Preferred for applying upward pressure on the support members hydraulic rams can be controlled either manually or hydraulically or automatically operate. If automatic, the system is preferably set by setting a pressure to be maintained is regulated by hand in the hydraulic system. Instead, the pressure can be regulated automatically according to the metal temperature of the pipe will. Feathers can be used in place of the ram, though using it preferred by rams.

When an upward tension is applied and the tubes under the Oven hearth are anchored, the anchoring to a support member or another equipment used in connection with the furnace, e.g. B. a quenching chamber or a second furnace. Where a quenching chamber is used, the the tubes preferably extend a short distance into the container. Advantageous a single cylindrical container is used, and all tubes in one cell or in a series of cells are anchored to the container. Such a container is preferably horizontal with its longitudinal axis just below the longitudinal axis be arranged of the furnace. The container should be able to withstand pressures above the to resist atmospheric.

Such a container can e.g. B. 1.20 m or more in diameter and 3 to 12 m long for commonly used oven sizes.

The multi-tube device described above, in which the support anchor forms a collector, which is preferably a spray chamber, is with a Container for quenching liquid and the establishment of a quenching system, which comprises a pump, a waste heat exchanger and a spray device. at the device is the hot drain from the pipes almost instantly with the sprayed quenching medium mixed. According to the method, a certain amount of volume in the quench chamber requires the sensible heat of the gaseous effluent is first reduced to condensate generating temperatures. The drain requires with further cooling, both sensible and latent heat are removed. at current practice normally places the gases outside the furnace limits only through cables as strong as they are required for discharge, guided, whereupon the discharge into fractionation towers or other cooling devices takes place. Such lines are very unsatisfactory when the gaseous effluent from the reaction tubes contains high-boiling substances, which tar or coke and the like on the hot walls the process control form. The quenching system described is very advantageous, because by the immediate introduction of the drain from the pipe in a proportionate large quenching container space the formation of such disadvantageous solid or highly viscous Substances in the lines are avoided.

For example, if the oven cell or oven has three rows of 20 cm pipes has, which in the form of a hollow square centered at right angles to the axis of the quenching vessel and center-to-center by two pipe diameters are separated, the container diameter will preferably exceed four pipe diameters and have a pipe diameter of at least 81 cm. A container is advantageous used with a diameter of 120 cm or more. At least one end of the container is extended beyond the furnace, as shown in Fig. 4, to include the mixed, gases essentially free of entrained substances by means of a single line essentially to be withdrawn directly into the next associated piece of equipment. Consequently the container itself performs a multiple function in that it is a quenching container represents temporary separator and effective line.

In the operation of the quenching system, it is preferred to use quenching liquid, usually condensate, generated by a heat exchanger waste heat evaporator circulated by steam, either as process steam for the reaction tubes used or injected with the oil used for oil heating in the furnace will. The waste heat evaporator and quench tank can be inside a single one Device part be combined, although preferably a separate waste heat evaporator and a separate quench tank can be used.

The gaseous effluent from the pipes usually becomes a temperature of 5400 C, and it is therefore usually preferred to have a portion to cool the container on the pipes. This cooling can be done by means of a cooling jacket take place through which a coolant circulates. The gaseous effluent is normally be cooled to a temperature of about 2000 C if a waste heat evaporator is used will. A substantial amount of liquid hydrocarbons can be used during cooling depending on the starting material, the type of cracking process and the temperature of the coolant are deposited. This liquid either goes to the pipes returned in a mixture with fresh starting material or a further treatment supplied or used as fuel.

The container itself or a smaller vessel can if desired in the same arrangement as a second catalytic reforming or cracking furnace to be used. The container can suitably have a charging nozzle be equipped so that the catalyst can be easily inserted and removed, if the system is to be used as a second furnace. The catalyst within the container can be supported by a grate or inserted at the top of the tube and dropped into the container, leaving a cone of material below it each pipe and above the normal height of the Catalyst layer within the Container forms. The removal of the tubular catalyst is simplified as a result, that the tubular catalyst can be removed by simply removing the catalyst in the second furnace falls down. The height of such a catalyst cone can easily be regulated thereby be that the cracking tube extends a greater distance into the second furnace vessel will.

The part of the tube protruding into the container can, if desired be perforated to allow the low resistance gas to flow out of the cracking tube to allow the zone above the catalyst layer in the second furnace. These pipes can then be extended all the way to the bottom of the container thus providing support for the pipes within the second furnace itself. In In this case, an expansion connection can be provided because the pipe is then connected two points inside the second furnace and where the pipe goes through the jacket of the second Oven passes through, is attached.

The claimed mode of operation and apparatus can be used for any desired appropriate response can be used. In the production of hydrogen and olefins all commonly used raw materials from methane to crude oil can be used will.

In the same way, any reforming agent used in technology can and cracking catalyst can be used in the catalytic reactions.

Claims (6)

PATENT CLAIMS 1. Process for the transfer of heat in a vertical position arranged reaction tubes made of metal in fireproof brick heating chambers one Tube furnace, especially for the production of hydrogen or olefins from liquid Hydrocarbons or hydrogen by methane reforming, characterized in that that at different levels of elevation flows of hot combustion gas obliquely to the Walls of the heating chamber are introduced into the chamber, the heating gas flows so be kept out of contact with the reaction tubes for a long time until combustion of the heating gas has occurred and so a zone of burned heating gas around the reaction tubes is formed and wherein preferably the heating gases spiral upward through the Chamber ceiling are removed. 2. Tube furnace for performing the method according to claim 1, with a refractory, brick-built heating chamber with reaction tubes arranged vertically therein made of metal, which pass through the heating chamber and at a distance from the chamber wall are arranged, characterized by elongated walls in thicker parts of the chamber trained chimneys (15, 25) and heating burners (16, 26), with the chimneys arranged in different height levels and so in the chamber wall are that extending a straight line from the torch nozzle to the end of the inner chimney wall drawn between the reaction tubes and the adjacent chamber wall passes through it, preferably at least one of the burner chimneys having an extension angle from 20 to 300. 3. Tube furnace according to claim 2, characterized in that the tubes (18, 24, 30) from one another from center to center a distance of 1 1/2 to 2t / 2 pipe diameter exhibit. 4. Tube furnace according to claim 2 and 3, characterized in that the tubes (30) on one quenching tank located below the furnace (3) are attached. 5. Tube furnace according to claim 2 to 4, characterized in that each reaction tube (30) is attached below the heating chamber and by its anchor point from is under an upward tension, which is preferably over sprung, above of the furnace vault Hanger (37) and a support frame (45) and one hydraulic ram (46) and is at least 0.7 kg / cm2. Documents considered: German Patent No. 914 131; U lima n n, "Encyclopedia of Technical Chemistry", 2nd edition, Vol. 6, p. 180.