Abstract: The temperature distribution in a shell and tube type heat exchanger having an expansion joint is uniformized by improving the circulation efficiency of fluid in the shell side. The uniformization is attained by the heat exchanger having an invasion-preventing plate against the fluid in the shell side attached to the expansion joint installed around the periphery of the shell, and a method of catalytic gas phase oxidation reaction that uses the heat exchanger.

Abstract: An apparatus for the treatment of a waste gas that is capable of recovering the heat generated by the catalytic oxidation of a waste gas to the largest possible extent and allowing the temperature of the treated gas in a first waste gas pre-heater to be adjusted to an arbitrary level incapable of condensing moisture and/or corrosive gas is provided.

Abstract: A method for quickly starting up a reactor and a reactor system therefor are provided. A shell-and-tube reactor in the system is adapted to circulate a heat medium having a solid point in the range of 50-250° C. to the outside of the reaction tubes and characterized by initiating temperature elevation of the reactor by introducing a gas of a temperature in the range of 100-400° C. to the reaction tubes' side and then circulating the heat medium in a heated state to the outside of the reaction tubes. By introducing a gas of an elevated temperature preparatorily to the reaction tubes, it is made possible to prevent the heat medium after circulation from being solidified again and enable the reactor to be quickly started up.

Abstract: In a method for distilling (meth)acrylic acid and/or (meth)acrylic ester, the method has the step of uniformly distributing a supply liquid in a distillation tower over an entirety of a horizontal cross sectional area in the distillation tower. A distillation apparatus for distilling (meth)acrylic acid and/or (meth)acrylic ester in a distillation tower has a supply element for supplying the supply liquid into the distillation tower. The supply element is formed with at least two supply ports through which the liquid is supplied into the distillation tower.

Abstract: According to the present invention, a tank for storing an easily polymerizable compound, the tank fitted with a liquid inlet pipe 3, a liquid draw-off pipe 4 and a liquid recirculating pipe 5, is characterized in that, assuming terminal ends of the individual pipes 3-5 are located at the same height, the apex angle formed by a line joining the central points of the end openings of the pipe 3 and the pipe 4 at the central point of a horizontal cross section of the tank, or the apex angle formed by a line joining the central points of the pipe 5 and the pipe 4 at the central point of the horizontal cross section of the tank, is equal to or larger than 90°. A method of storing an easily polymerizable compound of the invention utilizes the aforementioned tank for storing the polymerizable compound.

Abstract: The temperature distribution in a shell and tube type heat exchanger having an expansion joint is uniformized by improving the circulation efficiency of fluid in the shell side. The uniformization is attained by the heat exchanger having an invasion-preventing plate against the fluid in the shell side attached to the expansion joint installed around the periphery of the shell, and a method of catalytic gas phase oxidation reaction that uses the heat exchanger.

Abstract: The present invention provides a process for producing (meth)acrylic acid by gas-phase catalytic oxidation, which comprises cooling and condensing a (meth)acrylic acid-containing reaction product gas to obtain a crude aqueous (meth)acrylic acid solution; cooling the aqueous solution to deposit the impurities contained in the aqueous solution, as solid matter; separating the solid matter; and then extracting and separating (meth)acrylic acid from the purified aqueous (meth)acrylic acid solution obtained. Unlike the conventional processes in which (meth)acrylic acid is extracted and separated from a crude aqueous (meth)acrylic acid solution, the present process can avoid various troubles caused by the impurities contained in the crude aqueous (meth)acrylic acid solution, for example, generation of scum and the like, and therefore can produce (meth)acrylic acid at a higher purity than in the conventional processes.