DE1905510C3 - Device for continuous measurement and display of the concentration of sulfur trioxide in a gas mixture - Google Patents

Description

I 905 510

A schematic drawing shows the structure and mode of operation of an exemplary embodiment explained in more detail according to the invention.

The gas mixture to be analyzed is first passed through a flow meter in a constant flow I regulated diaphragm pump 2 introduced into a reaction cooler 4 via a gas step nozzle 3. Vertically below the reaction cooler 4 is a separation column. 5 arranged in the via a Feed line 6 superheated steam from a superheater 7 flows in

In order to reduce the cooling rate of the gas mixture fed in via the nozzle 3, a heating rod 8 is installed axially in the reaction vessel 4 Sulfuric acid condenses and thus causes it to be washed out. However, the sulfuric acid leaving the cooler 4 still contains dissolved SO., And some CO.,. These components are separated again in the "* racing column 5, the inner wall of which is provided with surface-enlarging elements. This separation is essentially achieved by introducing superheated steam, whereby the SO ₄ and CO ₂ together with the above-mentioned steam metering return into the flue gas flow Moisture still contained in the flue gas is separated out in a Peltier cooler 28 and fed to a drainage system 15.

Freed from SO ₂ and CO *, the sulfuric acid condensate passes into an air cooler 9, in which it is first cooled and then thermostated to a constant temperature. The electrical conductivity is then determined in a conductivity measuring cell 10. This conductivity measuring cell is embedded in a heat-sealed, corrosion-resistant metal block 11 provided with a heater. As a result, the condensate supplied is always kept at a constant temperature.

The condensate then flows from the conductivity cell 10 into a condensate flow meter 12 and is then diverted via the drainage system 15. Two solenoid valves are used in the drainage system 15 13 and 14 a periodic filling and emptying of the drainage container 15 and thus a discharge of the condensate is reached without air penetration.

On the one hand to expel SO ₄ and CO ₃ and on the other hand for dosing into the flue gas. Water vapor is obtained in a separate evaporator system. From a deionized

reservoir 16 periodically flows Deionn over Three-way solenoid valve 17 in a metering tube 18. The deionized water storage container is also tight on the cover closed, only an air compensation tube 29 extends from the top to just above the bottom of the container. If the metering tube 18 is now arranged a little below the storage container 16, then it fills up. Metering tube 18 always only up to the level of the lower edge of the tube 29. As a result, in the metering tube always measure the same amount of water in a simple way. This is where the water comes in after the valve 17 has been converted into a containment container 19, which is provided via a lockable pressure equalization line 20 is connected to the actual evaporator 21. The deionized water flows from the inlet

ao lock container 19 via a further solenoid valve 22 in the evaporator 21 and is here under a low Overpressure evaporates.

The volume determined by the metering tube 18 and the opening times of the solenoid valves 17 and 22 controlled by a timer 23 determine the deionate inflow per unit of time to the evaporator. In the evaporator 21, the deionized material is evaporated by means of an electrical heater 24 under a constant slight overpressure of approximately 0.5 atmospheres regulated by a contact manometer 25. This overpressure is largely reduced by a nozzle 26 connected downstream of the evaporator 21. The initial reduction in pressure and thus fine regulation of the amount of steam takes place via a control valve 27, since ^r in

Effectiveness of the condensate flow meter 12 is. With this regulation, a constant Amount of condensate reached. After the control valve 27, the steam is superheated in the superheater 7 and then introduced into the separation column 5.

With the arrangement of a heating rod in the reaction cooler and the generation of the superheated steam from deionized water, there is on the one hand a complete separation of the SO ₃ components supplied and, on the other hand, an unadulterated measurement of the conductivity

♦ 5 of the condensate is guaranteed, so that primarily the proportion of SO ₃ in the flue gas can be measured and, secondarily, the firing of the boiler to be monitored can be optimally adjusted.

1 sheet of drawings

Claims (4)

1 2 patent is the un- Patent speech: terhalb the reaction Kohler arranged and ^p provided ten this upper Continuous thermally insulated separation column at its J. Gerit sur continuous measurement and check the inside of the surface enlarging Elemenzeige the concentration of Scbwsfeitrioxid in Figure 5 and has at its lower, in the Leiteinera gas mixture the remaining components ability measuring cell transferring end of a supply are insoluble in condensing water vapor, provision for the adjustable amount from the evaporator m, based on the conversion of the sulfur trioxide from one of the Uitbarkeitsroeßzelle downstream to sulfuric acid and measurement of the conductivity, th condensate flow meter controllable amount using a reaction cooler, the w Superheated water vapor and ι : n the upper end of the water vapor generated in an evaporator, a feed through which the gas mixture flows continuously, and a suction of the gas mixture to be measured.
arranged below the reaction cooler. The SO ₃ -An separation column determined with such a device for re-evaporating thermally does not, however, often deviate from the theoretically resistant components and one of the 15 calculated values. This deviation results from the conductivity measuring column downstream from the fact that if the SO ₃ cell cools down too quickly, whereby the Ui of the vertical extension gas forms sulfuric acid mist, the water vapors that are arranged and dense below the reaction cooler are not washed out into this heat-insulated separation column is, but rather flows upwards with the post gases on its interior with the surface coarsely flowing away. Since a perfect conversion and converging elements are provided and their densation of the SO ^ -Anteiles in the gas only occurs when the lower, in the conductivity measuring cell, a sufficiently long diffusion time for the individual the end of a supply for the gas particles from the Axis to the inner wall of the damper is adjustable, given by one of the conduction cooler and the particles do not already form condensate- »5 before fog, it is necessary to reduce the cooling quantity meter, the amount of inflowing speed in the reaction cooler.
superheated water vapor as well as at the upper end, it has also been shown that with clubs supply for the continuous suction application of the draining condensate as feed of the gas mixture to be measured, after water for the main patent 1 "73 763 in the reaction cooler from below, thereby marked 30 superheated steam to be introduced is characterized by the fact that a heating rod (6) is installed axially in the reaction cooler for a certain period of time due to the accumulation of white (4) and that the soluble acids in this condensate evaporator (21) is under overpressure and falsification of the measurement results is possible.
a separate Deionatvonatsbehälter (16) To avoid this last adulteration, it is fed. 35 known from German patent specification 1 203 502, 2. Device according to claim 1, characterized in that the evaporator is fed with fully desalinated water. draws that the evaporator (21) via a The invention is based on the object in Wei-introduction container (19) and one with a three-part formation of the device according to the main patent the Directional control valve (17) controlled metering tube (18) to improve the measuring device so that a complete Deiooat reservoir (16) is connected. 40 days of elimination of the gas contained in the gas mixture 3. Apparatus according to claim 1 and 2, characterized in that SO ₃ -AnteiIes is enabled and that disruptive indicates that the evaporator (21) has an influence from impurities or others with an expansion nozzle (26) and a component separated from the cone largely avoided densat flow meter (12) behind the conductivity. keitsmeßzelle (10) regulated valve (27) with 45 To solve this problem is therefore the invention a superheater (7) is connected. according to that provided axially in the reaction cooler 4. Apparatus according to claim 2, characterized in that a heating rod is installed and that the evaporator is impenetrable a pressure equalization line (20) is between the overpressure and a separate one Evaporator (21) and transfer container (19). Deionized water reservoir is fed. 50 By arranging such a heating rod in the reaction cooler, the cooling rate of the supplied gas mixture reduced so far, that fog formation is largely avoided and that at least 97% separation of the sulfur The main patent relates to a device that achieves 55 acidity. continuous measurement and display of the group to generate the superheated water vapor is tratton of sulfur trioxide in a gas mixture, the overpressure working evaporator the remaining ftjfflponeflten generally a condensing one, loading tank and one with a three- * Water vapor are ineffective) should the by-pass valve-controlled osienohr be connected to the deionized water 'Conversion of the sulfur trioxide to sulfuric acid and connected to the storage tank. On the other hand Messimg the conductivity, using a »is via an expansion nozzle and the evaporator Reaction sensor that is in an evaporator via a condensation meter behind the generated water vapor and the oas mixture through a 'conductivity measuring line controlled valve with a Is flowing, as well as a superheater connected below the reaction cooler. arranged separating column to separate them mixed non-resistant conical material and ßinschleus container in the evaporator ta guarantee · ., one of the conductivity bars downstream of the separation column, are bin lock container and evaporator with '■ " measuring cell, according to the invention connected to the main of a pressure compensation line.