Abstract: A method for supplying reaction gases in which at least a material to be oxidized and a gas containing molecular oxygen are mixed and the resultant mixture is supplied to a catalytic gas-phase oxidation reactor, characterized in that, a feed rate of the material to be oxidized and a feed rate of the gas containing molecular oxygen are adjusted so that when a composition of a gas at the inlet of the catalytic gas-phase oxidation reactor is changed from a composition A point [the concentration of the material to be oxidized: R(a), and the concentration of oxygen: O(a)] represented by plotting a concentration of the material to be oxidized and a concentration of oxygen in the gas at said inlet to a composition B point [R(b) and O(b)] [the composition A point and the composition B point are compositions outside an explosion range, and R(a)?R(b) and O(a)?O(b)], compositions on the way of the change from the composition A point to the composition B point fall outside the explosion range.

Abstract: The present invention aims to provide a transfer method and a transfer facility for an easily polymerizable substance that limits standing retention of the easily polymerizable substance in the feed pump, etc., and the generation and adherence of solid matter such as polymer or precipitate that accompanies such retention, in a facility in which respective feed pumps are disposed at the plurality of passages that branch off at the easily polymerizable substance inflow side and converge at the easily polymerizable substance outflow side. In this easily polymerizable substance transfer method, in the case where one feed pump 13 operates and the other feed pump 14 is stopped, a portion of the easily polymerizable substance is fed to feed pump 14 and second passage 12 in a direction that is opposite to the direction of flow of the easily polymerizable substance when feed pump 14 is activated.

Abstract: The present invention provides a support beam for use in an easily polymerizeable substance treatment apparatus. The support beam supports or reinforces an internal provided in the easily polymerizeable substance treatment apparatus. The support beam has an internal mounting portion to which the internal is attached, and a folded-back portion, at least part of which, is inclined downward with respect to a horizontal direction when approaching an end thereof.

Abstract: A catalytic combustion apparatus is equipped with a reactor for catalytically burning a gas to be treated containing a combustible organic compound, which further comprises a condensate forming means for condensing a part of a gas after reaction in the reactor, to form a condensate, and a pH measuring means for measuring a pH of the resultant condensate. It is preferred that the catalytic combustion apparatus still further comprise a temperature adjusting means for adjusting a temperature of at least a catalyst-packed portion of the reactor based on data measured by the pH measuring means.

Abstract: A method for handling an easily polymerizable substance and a device for handling an easily polymerizable substance are provided that prevent polymerization of the easily polymerizable substance in a bypass line by renewing the easily polymerizable substance retained in the bypass line of a flow control valve or flow meter installed in a line through which flows liquid containing an easily polymerizable substance. The method for handling an easily polymerizable substance renews liquid containing an easily polymerizable substance retained in the bypass line by intermittently opening and closing a bypass shutoff valve. The method for handling an easily polymerizable substance allows a portion of a liquid containing an easily polymerizable substance flowing through a line to flow through a bypass line by opening a bypass shutoff valve during handling of a liquid containing an easily polymerizable substance.

Abstract: A vertical multitubular heat exchanger that can prevent clogging of a polymerized material and is continuously operable for an extended period of time is provided. The vertical multitubular heat exchanger (1) of the present invention introduces a process fluid containing an easily-polymerizable substance into heat exchanger tubes (28) to perform heat exchange. The vertical multitubular heat exchanger (1) includes a shell (2) extending in a vertical direction, an upper tube sheet (8) and a lower tube sheet (10) respectively disposed at the upper portion (4) and the lower portion (6) of the shell (2), and a plurality of heat exchanger tubes (28) whose outer circumferences (26) of both ends are respectively fixed to the upper tube sheet (8) and the lower tube sheet (10). An upper surface (34) of the upper tube sheet (8) is formed to be sloped and at least one of the heat exchanger tubes (28) is disposed in the vicinity of the lowest position of the upper surface (34) of the upper tube sheet (8).

Abstract: The method for preserving a catalyst of the present invention is characterized in that, in a process for continuously producing an objective product by a vapor phase oxidation reaction using a phosphorus-molybdenum-vanadium catalyst containing phosphorus, molybdenum and vanadium, the phosphorus-molybdenum-vanadium catalyst retained in a reactor is maintained under a condition of a water content of 30 mg or less per 1 g of catalyst dry weight, before the start of the reaction or during the stop of the reaction. By this, deterioration of the catalyst retained in the reactor can be simply prevented.

Abstract: The present invention provides an apparatus for producing hydroxyalkyl(meth)acrylate and method for producing hydroxyalkyl(meth)acrylate, which can maintain high sealing performance even if the maintenance frequency of the blowdown valve is reduced. The apparatus for producing hydroxyalkyl(meth)acrylate of the present invention has a reaction vessel for synthesizing hydroxyalkyl(meth)acrylate, which has a blowdown valve placed in the reaction vessel, and the blowdown valve is opened when discharging contents of the reaction vessel and is a ball valve. The method of producing hydroxyalkyl(meth)acrylate of the present invention involves producing hydroxyalkyl(meth)acrylate using the aforementioned apparatus for producing hydroxyalkyl(meth)acrylate.

Abstract: The present invention provides a support beam for use in an easily polymerizeable substance treatment apparatus for treating easily polymerizeable substances, the support beam being for supporting or reinforcing an internal provided in the easily polymerizeable substance treatment apparatus; comprising an internal mounting portion to which the internal is attached, and a folded-back portion at which the internal mounting portion is folded back so that at least part of the folded-back portion is inclined downward when approaching an end thereof.

Abstract: The present invention provides an apparatus for producing hydroxyalkyl(meth)acrylate and method for producing hydroxyalkyl(meth)acrylate, which can maintain high sealing performance even if the maintenance frequency of the blowdown valve is reduced. The apparatus for producing hydroxyalkyl(meth)acrylate of the present invention has a reaction vessel for synthesizing hydroxyalkyl(meth)acrylate, which has a blowdown valve placed in the reaction vessel, and the blowdown valve is opened when discharging contents of the reaction vessel and is a ball valve. The method of producing hydroxyalkyl(meth)acrylate of the present invention involves producing hydroxyalkyl(meth)acrylate using the aforementioned apparatus for producing hydroxyalkyl(meth)acrylate.

Abstract: A method for supplying reaction gases in which at least a material to be oxidized and a gas containing molecular oxygen are mixed and the resultant mixture is supplied to a catalytic gas-phase oxidation reactor, characterized in that, a feed rate of the material to be oxidized and a feed rate of the gas containing molecular oxygen are adjusted so that when a composition of a gas at the inlet of the catalytic gas-phase oxidation reactor is changed from a composition A point [the concentration of the material to be oxidized: R(a), and the concentration of oxygen: O(a)] represented by plotting a concentration of the material to be oxidized and a concentration of oxygen in the gas at said inlet to a composition B point [R(b) and O(b)] [the composition A point and the composition B point are compositions outside an explosion range, and R(a)?R(b) and O(a)?O(b)], compositions on the way of the change from the composition A point to the composition B point fall outside the explosion range.

Abstract: The method for preserving a catalyst of the present invention is characterized in that, in a process for continuously producing an objective product by a vapor phase oxidation reaction using a phosphorus-molybdenum-vanadium catalyst containing phosphorus, molybdenum and vanadium, the phosphorus-molybdenum-vanadium catalyst retained in a reactor is maintained under a condition of a water content of 30 mg or less per 1 g of catalyst dry weight, before the start of the reaction or during the stop of the reaction. By this, deterioration of the catalyst retained in the reactor can be simply prevented.

Abstract: A catalytic combustion apparatus is equipped with a reactor for catalytically burning a gas to be treated containing a combustible organic compound, which further comprises a condensate forming means for condensing a part of a gas after reaction in the reactor, to form a condensate, and a pH measuring means for measuring a pH of the resultant condensate. It is preferred that the catalytic combustion apparatus still further comprise a temperature adjusting means for adjusting a temperature of at least a catalyst-packed portion of the reactor based on data measured by the pH measuring means.

Abstract: A method for handling an easily polymerizable substance and a device for handling an easily polymerizable substance are provided that prevent polymerization of the easily polymerizable substance in a bypass line by renewing the easily polymerizable substance retained in the bypass line of a flow control valve or flow meter installed in a line through which flows liquid containing an easily polymerizable substance. The method for handling an easily polymerizable substance renews liquid containing an easily polymerizable substance retained in the bypass line by intermittently opening and closing a bypass shutoff valve. The method for handling an easily polymerizable substance allows a portion of a liquid containing an easily polymerizable substance flowing through a line to flow through a bypass line by opening a bypass shutoff valve during handling of a liquid containing an easily polymerizable substance.

Abstract: The present invention aims to provide a transfer method and a transfer facility for an easily polymerizable substance that limits standing retention of the easily polymerizable substance in the feed pump, etc., and the generation and adherence of solid matter such as polymer or precipitate that accompanies such retention, in a facility in which respective feed pumps are disposed at the plurality of passages that branch off at the easily polymerizable substance inflow side and converge at the easily polymerizable substance outflow side. In this easily polymerizable substance transfer method, in the case where one feed pump 13 operates and the other feed pump 14 is stopped, a portion of the easily polymerizable substance is fed to feed pump 14 and second passage 12 in a direction that is opposite to the direction of flow of the easily polymerizable substance when feed pump 14 is activated.

Abstract: A vertical multitubular heat exchanger that can prevent clogging of a polymerized material and is continuously operable for an extended period of time is provided. The vertical multitubular heat exchanger (1) of the present invention introduces a process fluid containing an easily-polymerizable substance into heat exchanger tubes (28) to perform heat exchange. The vertical multitubular heat exchanger (1) includes a shell (2) extending in a vertical direction, an upper tube sheet (8) and a lower tube sheet (10) respectively disposed at the upper portion (4) and the lower portion (6) of the shell (2), and a plurality of heat exchanger tubes (28) whose outer circumferences (26) of both ends are respectively fixed to the upper tube sheet (8) and the lower tube sheet (10). An upper surface (34) of the upper tube sheet (8) is formed to be sloped and at least one of the heat exchanger tubes (28) is disposed in the vicinity of the lowest position of the upper surface (34) of the upper tube sheet (8).