DE36721C - Process and apparatus for separating water vapor from its mixture with sulphurous acid - Google Patents

Description

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PATENT OFFICE,

PATENT LETTERING

CLASS 12: Chemical apparatus and processes.

EMIL HÄNISCH and Dr. MAX SCHROEDER in NEUMÜHL-HAMBORN a. Rhine.

sulphurous acid.

Patented in the German Empire on February 9, 1886.

The separation of large quantities of water vapor from a boiling hot mixture with gaseous sulphurous acid, as is obtained in many processes, presents certain difficulties. The condensation of the steam brought about by indirect cooling by means of cold water has the disadvantage that relatively large lead apparatus, cooling coils, pipe systems, etc., are required for this, and that the effect is nevertheless only inadequate, since the steam is in the middle of the apparatus passes through unhindered. Furthermore, if the temperature of the cooling apparatus is not kept close to the boiling point, the precipitated steam always precipitates considerable quantities of the S O ² gases, which are readily soluble in water. If, however, the hot mixture of sulphurous acid and steam is to be used directly, be it for the preparation of rich, S O ² -containing waters or for the preparation of a solution of acid sulphurous lime or other salts, the absorption apparatus is again activated by the The steam is too hot, which impairs the solubility of the sulphurous acid.

The aim of the new process is to extract the steam from the gas mixture mentioned by direct Remove water injection. It can be seen that by injecting cold In addition to steam, water also contains sulphurous sulphurous substances, which are easily absorbed by water Acid must be condensed.

If the SO ² solution thus formed is now fed in a steady countercurrent to the hot mixture of steam and sulphurous acid, the temperature of this solution will gradually increase until it has finally reached the boiling point of water. In the same Mafse but as the temperature of the 5Ό rises initially obtained ² solution in the same Mafse their PUFA SO ² - Remove the content until it schliefslich at ι oo ° G. approximately equal to zero. The relationship between the decrease in the SO ² content and the increase in temperature is shown in the table below:

Content of SO ^{2 in} the solution:

at 20 ° C. = 8.6 pCt. S O ² ,

- 30 ° C. = 7.4 - -

- 40 ⁰ C. = 6.1 -

- 50 ⁰ C. = 4.9 -

- 60 ° C. = 3.7 -

- 70 ⁰ C. = 2.6 -

- 8o ° C. = 1.7 90 ⁰ C. = 0.9 -

- 100 ° C. = 0.1 - -.

If the process is now directed by regulating the water injection, so that the draining off Water is 95 to 100 ° C. hot, so the latter can, as from the preceding Table shows, do not carry significant amounts of sulphurous acid with you. The steam, on the other hand, must, if only the path of the countercurrent is long enough, be complete

Claims (2)

be condensed, since it cannot uncondensed past the injecting cold water. A lead tower exposed with chamottes and pieces of coke, as shown in the drawing, is best suited to carry out this process. The mixture of sulphurous acid and water vapor flows down through the tube α into the tower and rises up between the plates and pieces of coke. If a corresponding amount of cold water is now injected at the top through the shower b, both the steam and the sulphurous acid are condensed and flow back through the tower as an aqueous solution of sulphurous acid. When flowing low in the tower, however, the SO2 solution encounters new, steadily flowing hot steam and gas, which transfer their heat to the colder liquid flowing down, with the condensation of the steam, the temperature of the latter rising gradually to 100 ° C. With the increase in temperature, however, the originally absorbed sulphurous acid is given off again, while the condensed steam water with the injected water reaches the drain below through pipe c. If the tower has been in operation for some time, the condition has been regulated in such a way that the temperature of the water flowing down rises uniformly from top to bottom to the boiling point, while conversely the temperature of the rising gas mixture falls from the boiling point to the usual temperature. As a result of this, the vapor content of the gas decreases steadily and moderately from bottom to top, and the percentage SO2 content increases evenly become strong that the injected water is insufficient for its absorption, so that a regular stream of vapor-free, gaseous, sulphurous acid flows out of the tower through the pipe d and is used for further use. Absorption can be performed. If besides the steam there are other easily condensable impurities of the sulphurous acid, they are also precipitated with the water. The rimmed plates in the lower part of the tower are used, in particular, so that the water flowing down is retained for a long enough time and that the rising steam is provided with a sufficient heating surface. These plates can, however, also be replaced with coke filling, if the tower is built correspondingly higher, so that the water is retained in the tower by the unevenness of the coke so long that this time is sufficient to heat it to boiling heat. Pat τ claims: 1. Process for the separation of sulphurous acid and water vapor in that the S O ² solution obtained when cold water is injected into this gas mixture continues to counteract the hot gas flow until the solution is absorbed with steady release of the originally absorbed gas sulfurous acid is brought close to boiling point; so that on which a cooking torrid one end of the counter-current system, S 0 ² low-carbon liquid, at the other end a cooled, substantially freed of steam S O resultirt ² stream. 2. For the patent claim i. Protected method the use of one with plates or pieces of coke filled tower. For this purpose ι sheet of drawings.