公开(公告)号：US4023938A

公开(公告)日：1977-05-17

申请号：US568341

申请日：1975-04-15

申请人： Hans Guth ,  Gerhard Jonas ,  Klaus Kleine-Weischede ,  Hermann Wieschen ,  Hans-Joachim Kaiser ,  Karl-Heinz Dorr ,  Hugo Grimm

发明人： Hans Guth ,  Gerhard Jonas ,  Klaus Kleine-Weischede ,  Hermann Wieschen ,  Hans-Joachim Kaiser ,  Karl-Heinz Dorr ,  Hugo Grimm

IPC分类号： B01D53/14 ,  B01D53/18 ,  B01D53/26 ,  C01B17/56

CPC分类号： B01D53/263 ,  B01D1/007 ,  B01D53/14 ,  B01D53/1406 ,  B01D53/18 ,  C01B17/56

摘要： In the removal of water from a gas by contact with sulfuric acid, the improvement which comprises supplying the sulfuric acid in finely divided form having a surface of about 10.sup.4 to 10.sup.7 m.sup.2 /h at a concentration of about 95 to 99% and a temperature of about 35.degree. to 80.degree. C and with a contact time of about 0.2 to 2 seconds, whereby the residual moisture content of the gas is reduced to about 30 to 250 mg of H.sub.2 O/Nm.sup.3. Preferably the sulfuric acid is sprayed through a constriction into a vessel through which the gas is passed. The large sulfuric acid surface area permits high levels of dehydration to be achieved with far less sulfuric acid than heretofore believed possible and with small vessels and minimal contact times. Contact may be effected serially in several stages with the spent acids combined, brought up to initial concentration and recirculated.

摘要翻译： 在通过与硫酸接触从气体除去水时，其改进包括以约95至99％的浓度提供具有约104至107m 2 / h表面的细碎形式的硫酸和温度 约35℃至80℃，接触时间约0.2至2秒，从而将气体的残留水分降低至约30至250mg的H 2 O / Nm 3。 优选地，硫酸通过收缩部喷射到气体通过的容器中。 大的硫酸表面积允许以比迄今所认为可能的少得多的硫酸和小容器和最小的接触时间来实现高水平的脱水。 接触可以在几个阶段中连续进行，废酸组合，达到初始浓度并再循环。

公开(公告)号：US4163047A

公开(公告)日：1979-07-31

申请号：US811798

申请日：1977-06-30

申请人： Karl-Heinz Dorr ,  Georg Daradimos ,  Hugo Grimm ,  Georg Schmidt ,  Rudolf Gerken ,  Christoph Mucke ,  Hermann Wieschen

发明人： Karl-Heinz Dorr ,  Georg Daradimos ,  Hugo Grimm ,  Georg Schmidt ,  Rudolf Gerken ,  Christoph Mucke ,  Hermann Wieschen

IPC分类号： C01G49/14 ,  C01B17/50 ,  C01B17/74 ,  C01B17/90 ,  C01G49/02 ,  C01G23/00

CPC分类号： C01B17/901 ,  Y10S423/02

摘要： A process for the recovery of sulfuric acid from waste sulfuric acid containing iron sulfate and from solid iron sulfate of high water content of crystallization which consists essentially of:A. concentrating waste sulfuric acid to an acid concentration of 25-55 weight percent, based upon the suspension, by removing water therefrom;B. mixing the concentrated acid of Step A with recycled concentrated sulfuric acid obtained from Step E to form a resultant acid mixture of acid concentration of 30-65 weight percent, based upon the suspension;C. adding said solid iron sulfate of high water content of crystallization to the acid mixture of Step B thereby obtaining iron sulfate of low water content of crystallization;D. separating the iron sulfate of low water content from the resultant sulfuric acid solution of Step C;E. concentrating the separated sulfuric acid solution of Step D to an acid concentration of 45-70 weight percent, based on salt-free acid, and recycling at least a portion thereof to Step B; andF. thermally decomposing the iron sulfate from Step D to produce iron oxide and sulfur dioxide.

摘要翻译： 一种从含硫酸铁的废硫酸和硫酸高固含量的硫酸中回收硫酸的方法，该方法主要包括：

公开(公告)号：US4368183A

公开(公告)日：1983-01-11

申请号：US203285

申请日：1980-11-03

申请人： Karl-Heinz Dorr ,  Hugo Grimm ,  Ulrich Sander ,  Robert Peichl ,  Franz Maier

发明人： Karl-Heinz Dorr ,  Hugo Grimm ,  Ulrich Sander ,  Robert Peichl ,  Franz Maier

IPC分类号： C01B17/775 ,  C01B17/82 ,  C01B17/76

CPC分类号： C01B17/775

摘要： SO.sub.2 -containing, hot gases are catalytically converted in part in a first contacting stage. The water and the SO.sub.3 formed is removed from the reaction gas. The remaining gas is heated and then supplied to the second contacting stage. The water vapor content in the reaction gas delivered by a first contacting stage corresponds to an H.sub.2 O/SO.sub.3 mole ratio below 1. The reaction gas delivered by the first contacting stage is precooled by an indirect heat exchange to such a temperature that the wall temperatures of the heat exchanger are above the dew point temperature of the reaction gas. The precooled reaction gas entering a condensing stage is contacted in a venturi with cocurrent sulfuric acid of 98.0 to 100% concentration and a temperature of at least 95.degree. C. The exit temperature of the gas from the condensing stage is maintained at least at 120.degree. C. The gas rises in a succeeding absorption stage through a packing layer, which is contacted with trickling sulfuric acid having a concentration of 98 to 100% and a temperature of 70.degree. to 120.degree. C. The dry gas which leaves the absorption stage and has been freed from SO.sub.3 is maintained at a temperature which is as high as or slightly higher than the temperature of the acid as it initially contacts the packing in the absorption stage. The sulfuric acid concentration is controlled by a supply of water into the sulfuric acid in the condensing and/or absorption stage.

摘要翻译： 含SO 2的热气体部分地在第一接触阶段被催化转化。 所形成的水和SO 3从反应气体中除去。 将剩余气体加热，然后供给到第二接触级。 由第一接触阶段输送的反应气体中的水蒸汽含量对应于低于1的H 2 O / SO 3摩尔比。由第一接触阶段输送的反应气体通过间接热交换预冷至如此温度 热交换器高于反应气体的露点温度。 进入冷凝阶段的预冷反应气体在文氏管中与98.0至100％浓度的并流硫酸和至少95℃的温度接触。来自冷凝级的气体的出口温度保持在至少120℃ C.气体在接下来的吸收阶段通过填充层升高，该填充层与浓度为98-100％，温度为70-120℃的滴流硫酸接触。离开吸收阶段的干燥气体 已被除去的SO3保持在与吸收阶段最初接触填料时酸的温度高或略高的温度。 通过在冷凝和/或吸收阶段向硫酸中供应水来控制硫酸浓度。

公开(公告)号：US3997655A

公开(公告)日：1976-12-14

申请号：US618192

申请日：1975-09-30

申请人： Lothar Reh ,  Karl-Heinz Dorr ,  Hugo Grimm ,  Karel Vydra

发明人： Lothar Reh ,  Karl-Heinz Dorr ,  Hugo Grimm ,  Karel Vydra

IPC分类号： C01B17/765 ,  C01B17/76

CPC分类号： C01B17/765

摘要： Gases having a high SO.sub.2 content are catalytically reacted in a contacting zone having a plurality of series-connected contacting trays. A partial stream of partly reacted gases from the contacting zone containing SO.sub.3 is admixed with the SO.sub.2 containing gas before entering the first contacting tray. The gases are subjected to interstage cooling between contacting trays. At least a portion of the partly reacted gases is passed through an absorber prior to mixing with the feed stock gas having a high SO.sub.2 content. The rate at which SO.sub.3 is absorbed is increased in dependence on the loss of catalyst activity in the contacting zones such that the conversion of SO.sub.2 to SO.sub.3 in the contacting trays remains approximately constant.

摘要翻译： 具有高SO 2含量的气体在具有多个串联连接的接触盘的接触区中催化反应。 在进入第一接触盘之前，将含有SO 3的接触区的部分反应气体的部分气体与含SO 2的气体混合。 气体在接触盘之间经历级间冷却。 在与具有高SO 2含量的原料气体混合之前，部分反应的气体的至少一部分通过吸收器。 吸收SO 3的速率依赖于接触区中催化剂活性的损失而增加，使得接触塔盘中的SO 2转化为SO 3保持近似恒定。

公开(公告)号：US5030428A

公开(公告)日：1991-07-09

申请号：US325595

申请日：1989-03-20

申请人： Karl-Heinz Dorr ,  Hugo Grimm ,  Heinz Enumann ,  Jurgen Adlkofer

发明人： Karl-Heinz Dorr ,  Hugo Grimm ,  Heinz Enumann ,  Jurgen Adlkofer

IPC分类号： B01D53/60 ,  B01D53/74 ,  B01D53/86 ,  B01D53/94 ,  C01B17/76 ,  F23J15/00

CPC分类号： F23J15/006 ,  B01D53/8637 ,  C01B17/76 ,  F23J2215/20 ,  F23J2217/102 ,  F23J2219/10

摘要： In flue gases or other humid exhaust gases which contain NO.sub.x and SO.sub.2, the NO.sub.x content is reduced and the SO.sub.2 content is oxidized to SO.sub.3 by a catalytic processing and the SO.sub.3 content is subsequently condensed as sulfuric acid. In order to prevent a clogging and deterioration of the catalyst and a contamination of the sulfuric acid the flue gas is subjected before the catalytic processing to a fine dedusting by a scrubbing with hot dilute sulfuric acid. In dependence on the water content of the flue gases the concentration of sulfuric acid in the dilute sulfuric acid and the temperature of the latter are adjusted so that no water will be transferred from the flue gases to the dilute sulfuric acid and no water or only a small amount of water will be transferred from the dilute sulfuric acid to the flue gas.

摘要翻译： 在含有NOx和SO2的烟道气或其他潮湿废气中，NOx含量降低，SO2含量通过催化处理被氧化成SO3，SO3含量随后被浓缩为硫酸。 为了防止催化剂的堵塞和劣化以及硫酸在催化加工之前被污染，通过用热的稀硫酸洗涤来进行精细除尘。 根据烟道气的含水量，调节稀硫酸中硫酸的浓度和后者的温度，使得不会将水从废气中转移到稀硫酸中，不会将水或只有一种 少量的水将从稀硫酸转移到烟气中。

公开(公告)号：US4029751A

公开(公告)日：1977-06-14

申请号：US645125

申请日：1975-12-29

申请人： Karl-Heinz Dorr ,  Hugo Grimm ,  Waldemar Weber ,  Michael Tacke ,  Georg Schmidt

发明人： Karl-Heinz Dorr ,  Hugo Grimm ,  Waldemar Weber ,  Michael Tacke ,  Georg Schmidt

IPC分类号： C01B17/775 ,  C01B17/76 ,  B01D53/00

CPC分类号： C01B17/775

摘要： Sulfuric acid is produced from sulfur trioxide-containing humid gases by a process wherein the sulfur trioxide-containing humid gases are directly cooled with aqueous sulfuric acid, sulfuric acid is condensed and the gas is cooled below dew point of the sulfuric acid, and the water not required to form sulfuric acid is discharged as water vapor with the end gases.

摘要翻译： 硫酸由含三氧化硫的潮湿气体通过其中含硫三氧化物的湿气体用硫酸水溶液直接冷却，硫酸冷凝并将气体冷却至低于硫酸露点的方法制备，水 不需要形成硫酸作为水蒸气与末端气体一起排出。

公开(公告)号：US4910011A

公开(公告)日：1990-03-20

申请号：US284210

申请日：1988-12-14

申请人： Karl-Heinz Dorr ,  Hugo Grimm ,  Heinz Neumann ,  Norbert Olhms

发明人： Karl-Heinz Dorr ,  Hugo Grimm ,  Heinz Neumann ,  Norbert Olhms

IPC分类号： B01D53/50 ,  B01D53/77 ,  B01D53/86 ,  B01D53/94

CPC分类号： B01D53/8637

摘要： In flue gases or other humid exhaust gases which are relatively cold and contain SO.sub.2, NO.sub.2 and other gaseous pollutants, the SO.sub.2 content is oxidized to SO.sub.3 and the NO content is reduced by a catalytic treatment, the SO.sub.3 content is condensed as sulfuric acid and other gaseous pollutants are removed by being scrubbed with aqueous liquids at low temperatures. In order to heat up the flue gas to the temperature required for the catalysis, the flue gas is heated up in a first heating-up stage by an indirect heat exchange with the catalytically treated gas before the catalytic treatment, the heated-up gas is heated up further in a second heating-up stage to the temperature required for the catalytic treatment, the catalytically treated gas which has been cooled in the first heating-up stage is cooled further in an indirect heat exchanger below the dew point temperature of sulfuric acid and is subsequently fed to an SO.sub.3 condenser. The remaining sulfuric acid vapor is absorbed by sprayed dilute sulfuric acid to form a dilute sulfuric acid having a predetermined concentration, the gas leaving the SO.sub.3 condenser is scrubbed in a scrubber with a sprayed aqueous liquid and is thus cooled to 40.degree. to 60.degree. C. and the purified gas is reheated to the required chimney inlet temperature.

摘要翻译： 在相对较冷且含有SO2，NO2和其他气态污染物的烟道气或其他潮湿废气中，SO2含量被氧化为SO3，通过催化处理使NO含量降低，SO3含量以硫酸等浓缩 通过在低温下用含水液体洗涤除去气态污染物。 为了将烟气加热至催化所需的温度，在催化处理之前，通过与催化处理气体的间接热交换，在第一加热阶段将烟道气加热，加热气体为 在第二加热阶段进一步加热到催化处理所需的温度，在第一加热阶段中被冷却的催化处理气体在低于硫酸露点温度的间接热交换器中进一步冷却 并随后进料至SO 3冷凝器。 剩余的硫酸蒸气被喷射的稀硫酸吸收，形成具有预定浓度的稀硫酸，离开SO 3冷凝器的气体在洗涤器中用喷射的水性液体洗涤，并被冷却至40℃至60℃ 并将净化的气体再加热至所需的烟囱入口温度。

公开(公告)号：US3950493A

公开(公告)日：1976-04-13

申请号：US508443

申请日：1974-09-23

申请人： Karl-Heinz Dorr ,  Lothar Reh ,  Hugo Grimm ,  Karel Vydra

发明人： Karl-Heinz Dorr ,  Lothar Reh ,  Hugo Grimm ,  Karel Vydra

IPC分类号： B01D53/50 ,  B01D53/77 ,  C01B17/74 ,  C01B17/80 ,  B01D53/34

CPC分类号： C01B17/806 ,  Y10S261/54

摘要： A process for removing sulfur trioxide from gases wherein the sulfur trioxide-containing gas is treated with sulfuric acid in a Venturi absorber, the sulfur-trioxide laden sulfuric acid is passed in indirect heat exchange with a cooling fluid within the widening outlet of the absorber and the sulfur trioxide-laden sulfuric acid is separated from the gas phase.

摘要翻译： 一种从气体中除去三氧化硫的方法，其中在文氏管吸收器中用硫酸处理含三氧化硫的气体，将含硫三氧化硫的硫酸与吸收器加宽出口内的冷却流体进行间接热交换， 将含三氧化硫的硫酸与气相分离。

公开(公告)号：US4008316A

公开(公告)日：1977-02-15

申请号：US270396

申请日：1972-07-10

申请人： Herbert Drechsel ,  Karl-Heinz Dorr ,  Hugo Grimm

发明人： Herbert Drechsel ,  Karl-Heinz Dorr ,  Hugo Grimm

IPC分类号： C01B17/765 ,  C01B17/72 ,  C01B17/68 ,  C01B17/70

CPC分类号： C01B17/7655

摘要： Process for production of SO.sub.3 by catalytic oxidation of SO.sub.2 which comprises carrying out the oxidation in two stages with intermediate absorption. The conversion of SO.sub.2 in the first stage is about 70-80% for a starting gas which is a cooled and cleaned roaster gas and 70-90% for a starting gas which is a sulfur combustion gas. The second stage comprises two catalyst beds, and the gas is cooled intermediate the beds. High overall conversion is obtained with low catalyst requirement.

摘要翻译： 通过SO2的催化氧化生产SO 3的方法，其包括在具有中间吸收的两个阶段中进行氧化。 对于作为冷却和清洁的焙烧炉气体的起始气体和作为硫燃烧气体的起始气体的70-90％，第一阶段中SO 2的转化率为约70-80％。 第二阶段包括两个催化剂床，气体在床之间冷却。 低催化剂需求可获得高的整体转化率。

公开(公告)号：US3944401A

公开(公告)日：1976-03-16

申请号：US467387

申请日：1974-05-06

申请人： Karl-Heinz Dorr ,  Hugo Grimm ,  Ulrich Sander ,  Robert Peichl ,  Michael Tacke

发明人： Karl-Heinz Dorr ,  Hugo Grimm ,  Ulrich Sander ,  Robert Peichl ,  Michael Tacke

IPC分类号： B01D53/48 ,  B01D47/10 ,  B01D53/34 ,  B01D53/50 ,  B01D53/77 ,  C01B17/74 ,  B01D47/14

CPC分类号： B01D53/34 ,  B01D47/10 ,  C01B17/74 ,  Y02P70/34

摘要： Sulfur compounds oxidizable to form sulfuric acid and organic compounds oxidizable to CO.sub.2 and H.sub.2 O are removed from an exhaust gas of a contact-process plant for producing sulfuric acid by treating the exhaust gas with a scrubbing solution consisting of dilute sulfuric acid and peroxydisulfuric acid. The peroxydisulfuric acid is produced electrolytically from fresh dilute sulfuric acid and the resulting electrolyte is continuously introduced into the scrubbing acid cycle. The exhaust gas is treated in a vertical venturi with uniflow, i.e. codirectional flow of the gas and the scrubbing solution, and the gas is then passed through a horizontal venturi and subsequently upwardly through a packing layer.CROSS-REFERENCE TO RELATED APPLICATIONThe present Application is related to the commonly assigned copending application Ser. No. 308,849 filed Nov. 22, 1972 and entitled METHOD OF REMOVING GASEOUS IMPURITIES FROM WASTE GASES now abandoned. The latter application relates to subject matter disclosed and claimed in copending application Ser. No. 74,629 filed Sept. 23, 1970 now abandoned, commonly assigned copending application Ser. No. 188,127 filed Oct. 12, 1971, and commonly assigned copending application Ser. No. 188,128 filed Oct. 12, 1971, now U.S. Pat. Nos. 3,780,499 and 3,788,043 respectively, all dealing with absorption systems and gases containing sulfur oxides and naming one or more of the present joint inventors.FIELD OF THE INVENTIONThe present invention relates to a process for the removal of sulfur compounds oxidizable to form sulfuric acid and organic compounds oxidizable to form CO.sub.2 and H.sub.2 O from the exhaust gases produced by contact-process plants for making sulfuric acid.BACKGROUND OF THE INVENTIONAs pointed out in application Ser. No. 308,849, sulfur-containing gases and particulates are a major problem in modern societies because they are released into the atmosphere from many sources and are highly toxic to the population, to vegetation and to metal, stone and other structures.In the combustion of fuel oil and coal, for example, elemental sulfur and sulfur oxides may be released into the atmosphere.From chemical plants, organic sulfur compounds, hydrogen sulfide and sulfur oxides may be released into the atmosphere.In sulfuric acid plants, the waste gases following the final absorption may contain toxic or dangerous quantities of residual sulfur dioxide and sulfur trioxide.In the roasting of metal and other metallurgical processes, the release of elemental sulfur, and sulfur compounds, especially sulfur oxides, has long been a problem.Consequently, considerable effort has been made to obtain an efficient, low-cost system for removing sulfur compounds from waste gases and capable of minimizing the release of such gases into the atmosphere.A large number of processes have been suggested for this purpose as described, for example, in the literature references cited in application Ser. No. 308,849. These processes include washing the gas with sodium carbonate solution followed by crystallization of sodium sulfite, washing the gas with a magnesia slurry followed by crystallization and recovery of the magnesia as well as concentrated sulfur dioxide, washing the gas with gaseous potassium sulfite which is then recovered by stripping from the precipitated pyrosulfite. More complex and extensive systems may also be mentioned here, although they have been more or less fully described in the aforementioned copending applications as representing the state of the art. Suffice it to say that it has been discovered by some of the present applicants jointly with another, as decribed in application Ser. No. 308,849, that waste gases can be economically treated with a dilute sulfuric acid containing peroxydisulfuric acid in such manner that sulfur trioxide results. A critical feature of the system described in the last-mentioned application is that the peroxydisulfuric acid level in the treating solution is replenished by the electrolysis of fresh dilute sulfuric acid (electrolysis-cell acid) with the peroxydisulfuric acid solution thus produced being mixed with dilute sulfuric acid to form the gas-treating liquor. The peroxydisulfuric acid which decomposes upon treatment of the gas, the sulfuric acid formed by absorption of the sulfur trioxide in the dilute sulfur acid and the dilute sulfuric acid serving as the treatment vehicle and absorber can thus be drawn off without recycling to the electrolysis cell.Best results were obtained using this system with gas streams containing sulfur dioxide and those with the exhaust gases of combustion installations such as furnaces, metal or roasting plants and sulfuric acid plants.The system of application Ser. No. 308,849 may be used, in addition, to remove sulfur-containing impurities other than sulfur dioxide from an exhaust gas. It has been found that inorganic sulfur compounds containing sulfur in an oxidation state in which it can be oxidized to elemental sulfur and/or to sulfur dioxide can be removed with that system. For example, inorganic sulfides and hydrogen sulfide can be treated with the peroxydisulfuric acid solution and oxidized to elemental sulfur and eventually sulfur trioxide.The peroxydisulfuric acid concentration was preferably between 200 and 300 grams of peroxydisulfuric acid per liter in the cell acid, most advantageously between 240 and 260 grams per liter. At these concentrations a high yield or efficiency was obtained and practically no water was introduced into the system so that local overheating and thermal degradation of the peroxydisulfuric acid was avoided.The dilute sulfuric acid had a concentration of 25 to 60% by weight, this concentration giving the efficient washing and absorption characteristics. Sulfur trioxide, present in the exhaust gas, and/or sulfuric acid mist (which is generally present when the exhaust gas is derived from a sulfuric acid plant) can be removed simultaneously in spite of the fact that these components are not oxidized. The exhaust gas may contain organic compounds which are oxidized by the peroxydisulfuric acid system to carbon dioxide and water vapor.The gas was treated with the liquid phase in uniflow by passing the gas phase and the liquid phase jointly through the constriction of a venturi absorber. As described in applications Ser. Nos. 74,629, 188,127 and 188,128 and in our earlier individual and joint efforts, for reasons which are not fully understood the intimate contact produced by forcing the liquid phase jointly through a construction and thereafter permitting the mixture of the two phases to expand past the constriction yields a far more effective interaction of the two phases than can be obtained with theoretically equivalent washing towers in which the gas and liquid have similar contact times and interflow velocity. The gas, after the treatment with and separation from dilute sulfuric acid, was conducted through a droplet separator designed to avoid entraining of acid droplets along with the gas. The droplet separator was a packed bed traversed by the gas and from an impingement, collector and interaction surfaces which not only prevent passage of the acid droplets through the layer but also bring about an intimate contact of the gas phase with the acid in the form of a liquid film of the latter or so-called after-absorption and after-reaction.Where the gas is passed upwardly through a filter bed of this type, the lowermost layer consisted of a porous packing bed with particles of a particle size of 5 to 20 millimeters, preferably 9 to 15 millimeters. In this layer precipitation and removal of entrained acid droplets occurs. The packing bodies are coated with a liquid film in which the aforementioned after-absorption takes place. When this liquid film tends to become thicker, the sulfuric acid droplets fall from the layer. The rising gas stream and the pore size maintain a thin liquid layer above the packing mass.The after-absorption is preferably effected in a layer having a height of 50 to 200 millimeters, preferably 80 to 120 millimeters, this bed height having been found to provide after-absorption with a minimum of increased flow resistance. The gas velocity furing after-absorption was 1 to 2.5 meters per second, preferably 1.3 to 1.7 meters per second.After traversing the after-absorption layer of a thickness of 50 to 200 millimeters and composed of porous packing bodies with a particle size of 5 to 20 millimeters at a gas velocity of 1 to 2.5 meters per second, the gas passed through a layer of acid-resistance nonporous packing bodies with a particle size of 20 to 50 millimeters in an after-absorption stage, the latter overlying the after-absorption bed.The after-separation bed not only loads the after-absorption bed to prevent migration of the packing bodies but also provides impingement-type liquid-separation surfaces together with narrower and random channels in which residual droplets of acid may be separated from the gas phase. The after-separation bed has a thickness of 50 to 150 millimeters, preferably 80 to 120 millimeters, a range which has been found to be effective for efficient separation of the residual liquid from the gas phase without materially increasing the flow resistance.It was found to be desirable to treat the gas (containing sulfur compounds and other compounds oxidizable by peroxydisulfuric acid to sulfur dioxide, carbon dioxide and water vapor) with a dilute sulfuric acid containing the peroxydisulfuric acid in a venturi-type apparatus in uniflow, i.e. a system in which the gas and liquid phases flow in the same direction. The venturi absorber was provided ahead of the venturi constriction and expansion chamber with a liquid-collecting chamber and means for diverting the gas stream from its axial flow direction as it emerges from the venturi chamber. The gas stream was diverted by an angle of 90.degree. or more, thereby causing droplets of high kinetic energy to pass through the bodies of liquid in the bath disposed ahead of the venturi outlet. The venturi absorber was preferably oriented vertically so that its outlet was directed downwardly into this bath and the expansion chamber was provided with lateral outlets above the bath so that the main body of gas is first directed downward toward the bath and is then diverted upwardly and laterally to shed larger droplets and high-energy particles.The acid collected in the sump was in part recirculated to the venturi. It was also advantageous to pass the gas phase into contact with the peroxydisulfuric acid/dilute sulfuric acid liquid phase by forcing the gas upwardly through a gas-permeable plate upon which the acid layer was provided. The gas-permeable plate was composed of a porous material such as sintered glass or porcelain. The gas permeability, gas-flow velocity and volume were so dimensioned that little or no sulfuric acid solution passed through the plate. Best results were obtained when the after-absorber and after-separator beds of packing were provided upon the perfoated plate or upon respective prerforated plates in cascade.The parts of the apparatus which came into contact with the acid solution were constituted from or were coated with acid resistance, preferably polyvinil chloride.OBJECTS OF THE INVENTIONIt is the principal object of the present invention to provide an improved method of removing gaseous impurities from the waste gases of a contact-process plate for producing sulfuric acid.Another object of the invention is to extend the principles originally set forth in application Ser. No. 308,849.SUMMARY OF THE INVENTIONAccording to the invention, this object is accomplished in that the exhaust gas is treated in a vertical venturi tube with cocurrent injected circulating scrubbing acid from the sump of the venturi tube, at least part of the injected scrubbing acid being separated and collected in the sump of the venturi tube.The gas is conducted into a substantially horizontal venturi tube disposed between the sump and the outlet opening of the vertical venturi tube and opening into a tower, the gas being treated in the horizontal venturi tube with cocurrent injected circulating scrubbing acid from the sump of the tower.The injected scrubbing acid is separated and is collected in the sump of the tower; the gas rising in the tower, which contains a packing layer, is treated with countercurrent circulating scrubbing acid coming from the sump of the tower and injected above the packing layer, and with the added acid electrolyte which contains peroxydisulfuric acid, and the acids fed into the tower are separated and are collected to the sump of the tower.Preferably a large part of the circulating scrubbing acid injected into the vertical venturi tube is separated and is collected in the sump of this venturi tube since even the scrubbing acid which has been entrained into the inlet of the substantially horizontal venturi tube as far as the throat thereof is recycled.The separation and recycling of the scrubbing acid which has been entrained to the narrowest part or throat of the substantially horizontal venturi tube from the vertical venturi tube may be accomplished by downwardly inclining the gas outlet conduit from the vertical venturi tube, or by the provision of baffles in the gas outlet conduit and by the provision of drain openings in the lower portion of the gas outlet conduit or in the inlet portion of the substantially horizontal venturi tube. These drain openings are connected by conduits to the sump of the vertical venturi tube.As a result of these measures, which may be used individually or in combination, a major portion of the scrubbing acid entrained from the vertical venturi tube is separated and conducted into the sump of that venturi tube so that the scrubbing acid cycles can be separated to a high degree.Advantageously, a large part of the circulating scrubbing acid injected into the vertical venturi tube is separated and is collected in the sump of the venturi tube because a packing layer is provided below the outlet opening of the venturi tube and above the inlet opening of the substantially horizontal venturi tube. This packing layer has a thickness of about 10-20 centimeter. The high turbulence produced in that layer also promotes the separation of the scrubbing acid, which is then collected in the sump of the vertical venturi tube.Scrubbing acid can be transferred from the sump of the tower via an overflow into the sump of the vertical venturi tube in a quantity which corresponds to the added electrolyte acid containing peroxydisulfuric acid and to the sulfuric acid formed as an oxidation product in the substantially horizontal venturi tube. In this simple way, a constant level is maintained in the tower sump and the entire system is operated in countercurrent of liquid and gas flow so that the active oxygen is optimally utilized. Besides, a steady-state concentration of active oxygen in the sump of the vertical venturi tube is maintained constant.The steady-state sulfuric acid concentration of the scrubbing acid in the sump of the vertical venturi tube is held constant by an addition of water. As a result, the evaporative loss of water is compensated and the heat of the resulting mixture is utilized for a hydrolysis of the residual peroxydisulfuric acid in the sump of the vertical venturi tube.The level of the sump in the vertical venturi tube is held constant by a withdrawal of scrubbing acid, which contains the oxidation product, from the sump. In that case, the product is withdrawn from the system at a point where the content of residual active oxygen is lowest.Different concentrations of sulfuric acid are maintained in the cycles of the circulating scrubbing acid, the highest concentrations of sulfuric acid and active oxygen being provided in the acid which is sprayed into the tower, a lower concentration being provided in the acid which is injected into the substantially horizontal venturi tube, and the lowest concentration being provided in the acid which is injected into the vertical venturi tube. This results in an optimum oxidation of SO.sub.2 and/or of other oxidizable gas components and an optimum utilization of the active oxygen supplied to the system.The electrolyte acid which emerges from the electrolytic unit and contains peroxydisulfuric acid consists of sulfuric acid which has a concentration of 30 - 50% by weight H.sub.2 SO.sub.4, preferably 35 - 40% by weight H.sub.2 SO.sub.4, and contains 180 - 350 grams, preferably 200 - 300 grams, peroxydisulfuric acid per liter. These concentrations give very good results in operation.Advantageously, the acid electrolyte which contains peroxydisulfuric acid is held in intermediate storage to increase the hydrolysis of the peroxydisulfuric acid. The increased hydrolysis of H.sub.2 S.sub.2 O.sub.8 to H.sub.2 SO.sub.5 and H.sub.2 SO.sub.4 results in a higher rate of oxidation of the gas components in the succeeding scrubber. Besides, the intermediate storage provides for a supply from which acid electrolyte which contains active oxygen can be withdrawn immediately at a suitable rate in case of fluctuations of the gas rate. Besides, the high SO.sub.2 content of the exhaust gas from a sulfuric acid contact process plant when being started up, may be absorbed in that the entire system is filled from the supply tank with electrolyte acid containing a high concentration of active oxygen so that there is initially a high content of active oxygen in all absorption stages.The intermediate storage is continued until a hydrolysis of 30 - 90% has been effected. That degree of hydrolysis gives good results in operation.The stationary steady-state concentration of the scrubbing acid in the sump of the tower most desirably amounts to 30 - 50% by weight, preferably 38 - 45% by weight, sulfuric and a molar concentration of active oxygen 0.4-1.26 moles, preferably 0.6-1.0 moles per liter. High degrees of oxidation are obtained with these concentrations.The stationary steady-state concentration of the scrubbing acid in the sump of the vertical venturi tube is advantageously 25 - 40% by weight sulfuric acid, preferably 28 - 32% by weight, and the active oxygen has a concentration of 0.06-0.3 moles per liter, preferably 0.1 - 0.15 moles per liter. A relatively high water vapor partial pressure in the gas phase and high degrees of oxidation are obtained with these concentrations.The residence time of the scrubbing acid which contains the residual peroxydisulfuric acid in the sump of the tower and in the sump of the vertical venturi tube is adjusted so that 20 - 90% of the residual peroxydisulfuric acid are hydrolyzed in each sump. The further hydrolysis of H.sub.2 S.sub.2 O.sub.8 to H.sub.2 SO.sub.5 and H.sub.2 SO.sub.4 improves the degree of oxidation. Besides, the volumes of the sumps can be dimensioned such that the higher SO.sub.2 content of the exhaust gases produced during the starting period of the contact process plant can be absorbed because an adequate supply of active oxygen is available.The included angle at the outlet of the vertical venturi tube and of the substantially horizontal venturi tube is 10.degree. - 20.degree., preferably 14.degree. - 17.degree.. As a result, the total gas pressure loss in the venturi tube is minimized and, in addition to the venturi effect proper, a turbulence is created to provide for an optimum gas-liquid interface allowing an optimum degree of oxidation.The gas is passed through the entire system with an average retention time of 2 - 4 seconds. This retention time allows a high degree of oxidation while keeping the dimensions of the equipment at a minimum.The withdrawn scrubbing acid which contains the oxidation product is supplied to the final absorber of the contact process plant. In this way, the residual active oxygen withdrawn from the system is utilized for an oxidation in the final absorber of the contact process plant and the content of oxidizable compounds in the exhaust gases is reduced before they enter the system.The quantity of peracids depends on the oxidation equivalent of the exhaust gas components to be oxidized and on the desired degree of oxidation and the desired purity of the exhaust gases.The packing layer in the tower has suitably a thickness of 40-80 centimeters. This results in a high degree of oxidation and in a relatively low gas pressure loss.The outlet opening of the tower is preceded by a wire mesh filter which provides for a good separation of entrained liquid in conjunction with a low pressure loss.The entire system can be made to a large extent from plastic or synthetic-resin material

摘要翻译： 通过用由稀硫酸和过氧化二硫酸组成的洗涤溶液处理废气，可氧化形成硫酸的硫化合物和可氧化成CO 2和H 2 O的有机化合物从用于生产硫酸的接触工艺装置的废气中除去。 过氧化二硫酸由新鲜的稀硫酸电解产生，所得的电解质连续引入洗涤酸循环中。 废气在垂直文丘里管中处理，具有单流，即气体和洗涤溶液的顺向流动，然后气体通过水平文丘里管，然后通过填料层向上。