Abstract: A new chemical reaction container (43) is provided which is suitable for a process plant the production of sulfuric acid according to the contact process. It comprises a cylindrical envelope surface and is divided by vertical separation walls into at least two sections, usually three. Each section has an inlet and an outlet, the separation walls at their bottom parts having one or several openings for making contact possible between the different sections. The advantage of this is that both the drying of the process gas, the interpass absorption step and the final absorption step may be conducted in one and the same reactor, instead of three separate reactors, as done previously. This saves both space and material. Further are provided a plant and a process for the production of sulfuric acid according to the contact process, which plant and which process comprise the above reactor container.

Abstract: For concentration and possible purification of mineral acids, particularly sulphuric acid, a furnace which can be heated is utilized, in which one or several long quartz tubes are placed. The quartz tubes are sealed at the upper and lower parts of the furnace and inside the furnace the quartz tube is heated from the outside with the utilized means. The acid which is to be treated is fed to the respective quartz tube via the upper parts of this, and the purified acid is collected in a vessel located at the lower parts of the quartz tube. Packings of small and/or medium dimensions are arranged in the quartz tubes.

Abstract: The present invention provides a unique structure for concentrating mineral acids, and particularly sulphuric acid wherein a plurality of long quartz tubes extend vertically through a furnace and have vertically lower ends in communication with a receiving vessel. The quartz tubes are surrounded by tube units and flow passageways are created on either side of the tube units for directing hot combustion gases along the quartz tubes, providing convective and radiative heat transfer to the tubes as required to heat the acid flowing therethrough. An assembly is positioned for generating turbulance within the gas flow passageway to achieve a vigorous turbulance of the hot combustion gases.

Abstract: The evaporating tubes of an acid concentrating system are positioned within a double-walled tube unit which directs heating gases over the tube and are supported at their lower ends on a spherical bearing surface which permits relative movement of the components without inducing unacceptable stress levels.