Abstract: A vertical centrifugal thin film evaporator is equipped with: a cylindrical body in which an central axis of a circle is set in a vertical direction; a rotor that rotates an interior of the cylindrical body in a circumferential direction thereof; a wiper that slides on an inner circumferential surface of the cylindrical body; a fixing support that fixes the wiper and is mounted on the rotor; and a heater that heats a circumferential surface of the cylindrical body. A liquid-withdrawing structure that communicates between a space surrounded by the wiper and the fixing support and a space outside the wiper and the fixing support is formed on at least one of the wiper and the fixing support, thereby preventing a liquid to be processed from being retained between the wiper and the fixing support.

Abstract: A vertical centrifugal thin film evaporator is equipped with: a cylindrical body in which an central axis of a circle is set in a vertical direction; a rotor that rotates an interior of the cylindrical body in a circumferential direction thereof; a wiper that slides on an inner circumferential surface of the cylindrical body; a fixing support that fixes the wiper and is mounted on the rotor; and a heater that heats a circumferential surface of the cylindrical body. A liquid-withdrawing structure that communicates between a space surrounded by the wiper and the fixing support and a space outside the wiper and the fixing support is formed on at least one of the wiper and the fixing support, thereby preventing a liquid to be processed from being retained between the wiper and the fixing support.

Abstract: Disclosed is a method for producing a hydroxyalkyl (meth)acrylate having high production efficiency and placing little burden on a production system. The method for producing a hydroxyalkyl (meth)acrylate comprises a reaction step of reacting (meth)acrylic acid with an alkylene oxide in a reactor while stirring a liquid containing (meth)acrylic acid and the alkylene oxide with a stirrer to obtain a reaction liquid containing a hydroxyalkyl (meth)acrylate, and thereafter a deaeration step of reducing a pressure in the reactor while stirring the reaction liquid with the stirrer to vaporize and remove an unreacted alkylene oxide in the reaction liquid, a number of stirring revolutions of the stirrer in the deaeration step being reduced to 30 to 85% of a number of stirring revolutions of the stirrer in the reaction step.

Abstract: Disclosed is a method for producing a hydroxyalkyl (meth)acrylate having high production efficiency and placing little burden on a production system. The method for producing a hydroxyalkyl (meth)acrylate comprises a reaction step of reacting (meth)acrylic acid with an alkylene oxide in a reactor while stirring a liquid containing (meth)acrylic acid and the alkylene oxide with a stirrer to obtain a reaction liquid containing a hydroxyalkyl (meth)acrylate, and thereafter a deaeration step of reducing a pressure in the reactor while stirring the reaction liquid with the stirrer to vaporize and remove an unreacted alkylene oxide in the reaction liquid, a number of stirring revolutions of the stirrer in the deaeration step being reduced to 30 to 85% of a number of stirring revolutions of the stirrer in the reaction step.

Abstract: A sandblaster system employs a blaster head which includes an essentially bowl-shaped blaster hood defining an internal collecting chamber. A blaster nozzle is inserted into the internal collecting chamber of the blaster hood and directed toward a surface to be treated. The blaster nozzle is connected to a source of working abrasive, such as working sand, to inject or discharge the working abrasive via pressurized air onto the surface to be treated. A sucking nozzle is also inserted into the internal collecting chamber of the blaster hood for removing pollutants generated in the blasting operation, such as dust, mine dust, removed rust metal and so forth, along with working abrasive. The sucking nozzle is connected to a vacuum source for inducting the the pollutant and the working abrasive to. On the other hand, the blaster hood is provided with elastic or resilient sealing member on the preripheral edge mating the surface to be treated.