DE1767980A1 - Tube furnace - Google Patents

Description

Dr.-Ing. Eichenberg
Dipl.-Ing.Sauerland ~ ö, OUM UOÖ

Dr. ! ng. king

DUSSELDORF

SOCIBTE ANONYME EEUETEY, in Paris (France) Drilling furnace.

The priority of the French patent application No. 115.705 of July 26 , 1967 has been claimed. .

The main problems which arise with tubular furnaces, especially those which are used to carry out the so-called reforming reactions ¹¹ in the presence of catalysts, are mainly problems with the mechanical strength of the bores and headers, as well as thermal problems.

In thermal insight, the temperature gradients at all points of the drill on habitual Verte be set as far as possible for the points of the same height of all drilling of the different layers formed by them are constant

From a mechanical point of view, the work must be made as small as possible, i.e. free expansion must be possible

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be, which, however, must be made as small as possible on the drilling itself and the header pipes as well as at their connection points. f? _t / f

In such a furnace it has already been proposed to "suspend the drill hole on elastic devices, which on the heads of the drill located outside the furnace attack, these heads with removable locking devices for the introduction and renewal of the catalytic converter and for the flexible connection to lines for the output the substances that should react with each other are provided *

These known arrangements have been applied to such furnaces with between each pair of drilling layers downwardly directed flames delivering rows of burners are arranged.

In these known arrangements, the bases of the wells are connected to auxiliary headers, which in some Removed from the base of the furnace or any other holder and attached to manifolds and transfer tubes are connected, which rise in the lower part of the furnace.

Furthermore, such ovens are known, the bottom of which is provided with exhaust gas discharge ducts between the drilling layers, some of which have the shape of an isosceles triangle to form secondary heat radiating surfaces which the Provide additional heat, which compensates for the distance between the burners in this zone of the drilling layers.

Ser-like drainage channels are generally with

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evenly distributed openings provided with constant cross-sections to allow the combustion gas to pass through? »; from the inside of the furnace to the inside of the flue 3 % ix .

The various known A & regulations have the following downsides:

-First of all, the total weight of the pipe layers and the auxiliary collecting pipes as well as part of the weight of the collecting pipes and the transfer pipes are completely supported by the bores and the corresponding elastic suspensions, as a result of which harmful stresses arise in the bores and their connections to the auxiliary collecting pipes, which « to those resulting from the effects of warmth ^! ■

This has the consequence that more metal is provided in the drilling

f must be, which reduces the efficiency of the arrangement and

increases the price;

- Furthermore, the connections between the drill feet and the auxiliary collecting pipes defenseless, 'CihaniscLen and exposed to thermal stress;

- the additional heat supplied by the secondary radiation from the flues is due to the uniform Distribution of the connection openings with constant cross-section made uneven, so that the lower sections of the Drill one and the same layer at the point of this radiation being heated unevenly along the layer «

The invention aims in particular to remedy the above disadvantages.

She has been trained in such an oven for this purpose to distribute the stresses on the object,

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which mainly in such a construction aid manifolds has, which rest with low friction on the sole of the furnace and with an elastic suspension of the Drill on their heads are combined

This results in reduced work in each drilling section on the support on the base and the suspension split at the head

According to a further characteristic of the invention every help collecting pipe is provided with a side exit which passes with a tight sliding fit through a wall of the furnace and to a slidable in the transverse direction empty manifold is connected.

According to a further characteristic of the invention, each manifold is in turn with an outer one by one elastic suspension held transfer tube combined. According to a further characteristic of the invention, are to reduce the displacement due to the expansion, the auxiliary manifolds and, if necessary, the manifolds themselves with middle anchoring on the sole or an equivalent Wall »whereby the displacements of their ends are reduced by half ·

The bores themselves slide in the roof of the furnace, stepping through roofing boxes.

The auxiliary manifolds are at the point of connection Both the drill hole and the connections themselves are protected by a temperature-resistant and insulating coating.

The header pipes and transfer pipes are preferably with internal temperature-resistant coatings and

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outer insulating coatings are provided, whereby the appropriate The work generated by the expansions can be reduced without loss of heat which affects the efficiency of the system to create.

In the radiant ducts of the sole, the radiant walls are supported by elements that can be placed next to each other, which form passages of adjustable cross-section between them the chamber of the furnace is provided, in which case only a single jet wall is present, since it only ends on one side needs to shine

The invention is explained below by way of example with reference to the drawing.

Pig. 1 is a cross section of an inventive Furnace with a simple manifold

Pig. 2 shows in the same way an oven with a double collecting tube

Figure 3 is a longitudinal section of a portion of the furnace of the Pig · 2.

Pig 4 shows schematically one type of thermal protection the auxiliary collecting pipes

Pig 5 and 6 are rope views of a type of connection of the pipes to an auxiliary collecting pipe, in section and in plan view

Pig · 7 shows schematically the type of fastening of the »suspension of the pipes ·

Pig. 8 and 9 show sohematisoh in profile b * w. in plan view with a furnace connected to a secondary furnace simple manifold.

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Pig. 10 UAd 11 show Ia in the same way one Furnace with double manifold.

In the example shown above there is an oven the reaction carried out on a suitable catalyst that for the production of a mixture of hydrogen and carbon oxide with the exit of water vapor and hydrocarbons with low molecular weights

The typical so-called "eeforming reaction" between the water vapor and the hydrocarbon with the lowest molecular weight is as follows:

OH ₄ + H ₂ O » CO + 3H ₂ .

In practice, this reaction is not complete, and in that out The regenerated gas exiting the furnace remains in the middle.

Ba, this reaction is endothermic, heat mass is supplied through the walls of tubes in which the phase gas steam flows so that this reaction in the presence of an appropriate catalyst at a approximately between 00 and 800 ⁰ C € lying temperature.

For this purpose, the furnace consists of a sheet metal jacket 1 which is correspondingly reinforced by profile iron 2 and which is inside is protected by an insulating cover 3 and an inner temperature-resistant layer 4

In the chamber thus formed layers of vertical tubes 5 are arranged, which in the desired number lie in as many parallel planes · The ceiling 6 of the chamber shows rows of burners 7, which are between the different ones Layers and on both sides of the Sndsohiohten lie, with the tubes 5 in corresponding openings freely through the Deoke and

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pass through a sighting described below with reference to Pig · 7.

The sole of the stove is with it over its entire length Provided openings 8 which open into an exhaust gas discharge duct 9, which if necessary to a Rohriceesel IO for recovery the sensible heat of the exhaust gases or other equipment is connected, in particular e.g. to a goal warmer for the combustion air supplied to the burners.

Auxiliary collecting pipes rest on the actual bottom 11 12, / which are tightly connected to the bores 5 of the corresponding layer

Each boring 5 has a removable plan 13 at the head above the ceiling 6, which gives access to the pipe and at the same time the connection of the same to one. Expansion connector educational. Stub 14 allows, which is formed by a flexible tube or a lyre, which in turn is connected to a distribution pipe 15, with all y Teiluagerohre to a line 16 for the supply of the "reforming reaction" Mixtures of steam and hydrocarbons to be subjected to are connected.

Every shift is outside of the oven Pair of tubes carried on the head by a swiveling cross member 17, to which an elastic suspension system is attached in the middle is, e.g. a spring 18, which in turn is attached to an upper cross member 19 of the framework of the furnace.

Each auxiliary manifold 12 is provided with a main manifold 20 connected., Which has a riser 21 in the middle

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for direct connection to a point for using the gases which have reacted with one another, or also a secondary furnace 22 (Pig · 8 and 9) »or to any other treatment apparatus, in which case this riser for an overpass is used.

As can be seen in particular from Pig 4, the tubes 5 of one and the same layer can lie in the same plane. However, each tube layer can also have two rows 5a. or have 5b, the tubes being arranged opposite one another or on the contrary in a checkerboard manner, as shown in Pig x 6. As can also be seen from Pig 3 to 5, each auxiliary collecting pipe 12 can protect against the direct radiation of the flames through a temperature-resistant shell 23 ζ «ex. from insulating temperature-resistant cement.

As already stated above, the tubes 5 of one and the same layer freely pass through the ceiling 6 of the furnace, and although in a box filled with Aebest fibers 24, which forms a seal, but allows the pipes to slide under the action of the expansions and contractions, themselves if the pipes were accidentally slightly deformed

As can be seen from Pig * 3, such a furnace may have pipe layers in the longitudinal direction, all of which are arranged in parallel planes. Pig · 3 shows only a final layer and a running layer section, but is natural the number of these layers make a puncture the one you want Production capability and can be made as large as you want.

The tubes 5 are preferably made of stainless steel on Hickel chrome, in order to be used for the Yornahm

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temperatures and pressures required for the desired reaction to endure. The diameter of the drill 5 will puncture this determined by both criteria.

The smallest inside diameter is given by the dimensions of the catalytic converter. This has to be in a Drill evenly distributed to prevent chimney formation, which would create a preferred passage. A large diameter, on the other hand, would be unfavorable because the one supplied Heat from the outer surface goes to the center of the tube. The usage of large diameter drilling under high pressure in the order of magnitude of 30 bar would be an impermissible metal dioke require.

For these reasons, drill 5 with an between 75 and 125 used on the lying inner diameter, which leads to appropriate metal thicknesses while maintaining the homogeneity of the catalyst.

Depending on the efficiency of the stove also only a single aid tube 12 is provided per shift as shown in Figures 1, 8 and 9, which has a side outlet on a single side, it can, however two help collecting tubes per shift are also provided, as shown in Figures 2, 10 and 11 with outlets provided on both sides. In Figs. 2, 10 and U are the same Parts, if these are symmetrical, are denoted by the same reference symbols with the indices a and b *

The auxiliary collecting pipes 12 rest on the bottom 11 with a bearing limited by the action of the elastic suspensions 18, and the play left at its end is

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possible equal axial expansions from the center of the auxiliary

l ,.

f ■ '

collecting pipes off »so that the end pipes 5 resemble a layer Are exposed to thermal stress. This is done through the passage left the desired freedom through the walls of the stove. There is a corresponding seal on the side walls of the furnace intended.

The auxiliary collecting pipes 12 are made of the same material as the drilling 5 and are attached to the actual collecting pipes 20 connected, which consist of a customary steel and an outer insulating cover and an inner temperature-resistant Have coating. This type of construction enables ^ the expansion of the headers 20 to reduce and a considerable To avoid transverse displacement of the auxiliary manifolds 12.

Bs is also possible to move the Help & manifolds 12 by equipping the corresponding main manifold 20 to avoid using a water jacket.

About the free axial expansion of the help collection tube To enable 12, the headers 20 expediently rest on holders 25 formed by bolts ('ig · 1 and 2), which the Allows distance and approach in relation to the cross winds of the furnace.

In order to further reduce the displacements of the auxiliary collecting pipes 12 both in the transverse direction and also in the longitudinal direction, an anchorage 26 or 26a, as shown in Yig · θ and 10, can be used. in the middle of the collecting pipes 20 or 20e ₄ , so that their axial expansion on both sides of this anchoring is reduced to half.

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The springs 18 are sized so that they are the largest Bear part of the weight of the drill and the catalytic converter, reducing the friction of the auxiliary collecting pipes on the bottom U and the stresses that arise as a result when the main collecting pipe 20 is stretched can be reduced. This suspension allows also the prevention of the kinking of the pipes 5.

In thermal terms, the burners 7 are aligned Arranged in rows · Your downward flames develop between the pipe layers and at equal distances of these. ^ j

The burners are arranged so close together in each row that they create a continuous veil of flame so that the same temperature gradient is achieved on all pipes at all heights of the furnace.

The number, the type, the unit output and the regulated supply of the burners 7 are determined in such a way that the the following conditions are met:

- The total output is sufficient for the preheating and the reactions as well as to compensate for the heat losses to transfer heat required on the walls and by entrainment by the exhaust gases exiting the furnace;

- the type and unit output of each burner are determined by the required flame length;

- the burners are so constructed and operate under conditions such that the flame veil nioht 1 direct contact with the adjacent Rohrsohichten comes;

- allows the number selected for the burners the manufacture of a continuous flame insole $

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- The combustion products flow through the furnace from top to bottom parallel to the pipe layers;

- The combustion gases are in the lower zone through at least one opening 8 with a distribution in the Longitudinal direction in the presence of several openings below Exhaust gas discharge channels 26 collected, which have a special training.

These have drainage channels in a running section approximately the shape of an isosceles triangle and are formed by a wall with two inclined surfaces 27. These Wall is formed by inclined plates 28, which are combined with a firet piece 29 and plugged into one another by notch joints are, in particular with hats and wedges, and their lower sections rest on feet 30. These passports will be formed by trimmed parts of prismatic shape, which are placed next to each other in the desired number in series, the series being separated from one another by supply openings 31.

These openings can depending on the axis of a corresponding Brenners lie, and it is possible to change their cross-section in the longitudinal direction so that one ' from them the same gas flows despite the influence of the output or output 8 receives. The passage cross-sections these openings are made according to their distance from Bucket output 8 enlarged to reduce the pressure increase within the Discharge ducts 26 to be taken into account.

As in particular from Flg. 3 shows, the tape withdrawal channels 26a have a wall with only a single Sohrag-

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surface 27a, which the channel 26a has the shape of a right-angled Triangle, which on the head by a special ridge stucco 29a of homologous form is completed.

On the side surfaces of the furnace, inspection doors (not shown) are provided at the location of each exhaust duct 26 or 26a, which allow access in particular to regulate the cross-sections of the openings 31, possibly with the help of additional temperature-resistant parts, not shown, which are placed in front of the openings and cause partial closure * μ

The walls formed by these flues guide the lower ropes of the drilling layers from the flames received radiant heat, which is converted and reflected on the adjacent sections of the drilling layers, around this one sufficient, uniform temperature gradient granted.

The burner in question can with suction air or Blown air work, particularly in the latter case reducing the negative pressure in the furnace and preheating the combustion air by utilizing the exhaust heat possible ·

As can be seen in particular from flg. 2 and θ to 11 (arrangement shown in dashed lines in fig * 2), a secondary "forming oven" 22 with a port is provided which is formed by a ΐβϋ of the riser 21 which lies horizontally and is held by a middle elastic system 32 and 32a, so that all are in mechanical The measures taken practically to a Lead neutralization of the stresses in the drilling pipes or at least make certain of them negligible

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Claims (4)

Claims 1.) Boring furnace, in particular iur performing reforming reactions in the presence of catalysts with vertically arranged pipe layers and upper parallel to the pipe layers downwardly directed Plamrnenschieiern, characterized by a support of the pipes (5), which an elastic head suspension (18) with a lower connection to auxiliary collecting pipes (12) combined, which rest with low friction on a sole (11) of the furnace, each auxiliary collecting pipe (12) has a lateral exit and outside the furnace is connected to a collecting pipe (20), which is on a transverse on a slidably displaceable support (25), each collecting pipe (20) being connected to a discharge or overhead conduit (21) held by an elastic suspension (32) * 2.) Furnace according to claim 1, characterized in that the auxiliary collecting pipes (12) and the collecting pipes (20) with middle anchorages (26) are provided 3 ») Furnace according to claim 1, characterized in that the heads of the tubes (5) slide in a Diohtungskasten (24) step through the roof (6) of the furnace 4.) Oven according to Anspruoh 1, characterized by an insulating protector (23) for the upper portions of the hip manifolds Q2) »which envelops the connection points of the auxiliary collecting pipes (12) with the pipes (5). 5 ·) Furnace according to Claim 1, characterized by exhaust gas discharge duct (26) with an approximately triangular cross-section, welohe with ^209811/1398 BADORIG.NAL by yüese with adjustable spacing formed supports (30) ▼ can be seen which, if necessary, with a partly iron lock effecting attached ropes cooperate, with the radiating Waade (27 «28, 29) of the drainage channels (26) through with an Eerbfuguag assembled temperature-resistant elements can be formed. 209811/1398