DE2320872C3 - Tube furnace - Google Patents

Description

of your part of the radiation zone ^ -nem - ^ _toffe

Tube with a correspondingly larger cross-section _{according to} their way

^ 2

pipes in the direction of flow of hydrocarbons increases. ,

3. Tube furnace according to claim 1 or 2, characterized in that the tubes (6, 7) are arranged essentially perpendicular ^ _temperature , _{are heated to} rich d «^ ^K 7, and the use

_bee inilußt, namely m

_binat ion of

result,

Broaching (11) consists

or.

Tubes (7) with a smaller cross-section in the spaces transverse to the central space (10) (H, are arranged.

l, _{ß to}

Te it ^ ^ ^ united

^S % _the total area between the raw

2 ^^

⁴⁰

The invention relates in particular to a tube furnace for the thermal cutting of coal wagons for the production of mainly ethylene containing hydrocarbon mixtures with

on Djnm ertan α _che ^ _{becomes with the} same

«Tap« port. «^^. ^ Koh ^ wass ^ s o« e

i ^ T _so that a shortening of the dwell time can be achieved ^ od ^ ^ _{throughput volume} .

Beam zone through a heated combustion chamber lebilden 'and the tubes in the radiation zone

S - * thermal

^ _{D £ Use to exercise} heat

That stay on the heating surface load

-tight ^ and ^ ^^ ^^ V ^

is the operator

SldrS radiation zone contain their walls and before

r ^ nwaSÄ

the pipe of the radiation zone will only be split

slightly increasing tempe

2007012; "Oil and coal-natural gas-petrochemical" better ones

the conventional design with constant pipe cross-section over the entire pipe length this maximum Temperature is only reached at the outlet of the Ofeas.

It is also very useful if the tubes are arranged essentially vertically.

In order to achieve optimal use of the available space, it is also particularly advantageous to when the tubes are arranged in an elongated, cross-sectionally double-T-shaped combustion chamber are made up of a central space with a rectangular cross-section and two at its end faces adjoining and transverse to this, also rectangular in cross-section rooms.

The subject of the application is a favorable temperature distribution over the length of the pipe also developed in such a way that the pipes with a larger cross-section in the central space? and the pipes are arranged with a smaller cross-section in the spaces lying transversely to the central space. In In the following numerical example, the operating results of the tubular furnace according to the invention are those compared to a conventional tube furnace:

Conven He 30th more functional finding Tube furnace more appropriate Tubes oven 35 Input product naphtha naphtha Ratio of water vapor 0.5 0.5 to naphtha Throughput / coil, 3406 3406 40 kg / h Maximum pipe wall 1027 1014 temperature, ⁰ C Outlet pressure, ata 1.9 1.9 Dwell time, sec. 0.5 0.36 C ₂ H ₄ yield, 23.3 24.1 Weight percent

A comparison of the operating results of the two furnaces shows that, with the same throughput, the residence time in the furnace according to the invention is about 28 ⁰ Zo less than in the conventional furnace. Nonetheless, if the pipe wall temperature is 13 ° C lower, there is still a greater ethylene yield.

Further details of the invention are based on the in FIGS. 1 to 4 shown schematically Embodiment explained in more detail. It shows

F i g. 1 shows a longitudinal section of the tube furnace according to the invention, F i g. 2 shows a cross section of the tubular furnace according to the invention,

F i g. 3 schematically the pipe routing and pipe union,

F i g. 4 the temperature profile over the length of the pipe.

For a better overview, similar parts in the figures are provided with the same reference numerals.

In Fig. 1 is a tube furnace 1 with a combustion chamber! shown, the walls 3 and the bottom 4 of which are provided with burners 5. Inside the combustion chamber 2 pipes 6, 7 are arranged in a serpentine and perpendicular manner. The tubes 6 have a larger cross-section than the tubes 7, which are connected via schematically indicated connecting tubes 8 from an inlet pipe 9 located outside the combustion chamber 2 can be fed.

F i g. 2 shows a cross section of the tubular furnace 1 with an elongated double-T-shaped combustion chamber 2, which consists of a centrally arranged, rectangular space 10 and two on its end faces adjacent and transverse to these, also rectangular rooms 11 is made. the Pipes 7 with the smaller cross section are arranged in the central space 10 transverse spaces 11 and are placed in the direction of the furnace center to tubes 6, which are arranged in the central space 10 are united, larger cross-section. For the sake of simplicity, there are only two different pipe cross-sections drawn.

In Fig. 3 is the pipe junction and the flow direction of the hydrocarbons schematically shown. The hydrocarbons flow in the direction of arrows 12 in two tubes 7, the are combined in the flow direction to form a tube 6 with a correspondingly larger cross section. The split Hydrocarbons leave the tube furnace in the direction of the arrows 13.

F i g. 4 shows a diagram in which the temperature T of the hydrocarbons is plotted over the pipe length L. The curve α here shows the temperature profile in the conventional design, that is to say in the case of a pipe with a constant cross section, while curve b shows the temperature profile in the case of the pipe union according to the invention. As can be seen from the diagram, a very high temperature is reached shortly after the entry of the hydrocarbons, which then rises only a little to the final temperature before the hydrocarbons exit the tube furnace.

In this way, the pipe materials used are almost the same over the entire length of the pipe highly stressed, and there is no danger at any point, such as at the end of the pipe according to the conventional one Design that the stress exceeds the permissible values.

1 sheet of drawings

Claims (1)

Patent claims: ! .Pipe furnace thermal treatment of hydrocarbons, especially for the production of mainly ethylene-extracting hydrocarbon mixtures
through a radiation zone, the zone being through a heated furnace and the pipes in the radiation zone »*“; iQfil No. 5, p. 350; "Chemist-14th Year, May 1 Voι, ι · j _3? ^ Zeitung ", 95th year ^^ _sraSchafte , issue 23, reports from TechniK" mu 1967, JU * _known he, ^ * «£ J ^ JU radiation zone arranged _{transverse cut} ^ ^ e'S SOFM the surface and * ^the ^ K3fctep £ unit length of a _dam it and the ^H ^^ ne F _ba uch the constant con- ^ For £ · "^^ _transferable temperature per _ ^ gi ⁿ _{chenbelastungj just} - _Wänneme length, ako the master ^ ^