Abstract: In order to simplify a configuration of a fluid system without increasing the number of parts of an intermediate support body while using a common intermediate support body, the fluid system includes a fluid circuit device configured by connecting a plurality of fluid units for controlling or measuring a state of fluid using pipes and pipe joints and a holding mechanism for holding the fluid circuit device, wherein the holding mechanism includes a base member and the intermediate support body interposed between the fluid circuit device and the base member so as to couple the fluid circuit device and the base member, and wherein one end of the intermediate support body is attached to a respective pipe joint and the other end thereof is attached to the base member so that each of the pipe joints is connected to the base member.

Abstract: A multi-tubular reaction apparatus, a control system, and a method are provided for controlling temperature change of a heat medium in the reaction apparatus, and quickly adjusting fluctuation in temperature, to thereby properly control a reaction. In particular, the apparatus and system apply to a catalytic gas-phase oxidation reaction such as in producing (meth)acrylic acid or the like. The reaction apparatus includes a multi-tubular reactor having a plurality of reaction tubes in a shell in which a heat medium circulates, and a heat medium cooling apparatus outside the reactor. The reaction apparatus includes a process for primarily cooling the heat medium taken out outside the shell, a process for secondarily cooling a part of the primarily cooled heat medium, and a line for enabling the secondarily cooled heat medium and the primarily cooled heat medium, which is not secondarily cooled, to circulate in the shell.

Abstract: An object of the invention is to provide a multi-tubular reaction apparatus and a control system for the same, the multi-tubular reaction apparatus being capable of controlling change in temperature of a heat medium, quickly adjusting fluctuation in temperature, and thereby, properly performing reaction, particularly, the apparatus and system properly applicable to a catalytic gas-phase oxidation reaction such as in producing (meth)acrylic acid or the like.