A reservoir for one or more chemical reactants has means for heating the reactants and optional means for stirring the reactants. A pumped reactant feed line and a return line provide fluid communication between the reservoir and a 4-way valve system. The 4-way valve system is also in fluid communication with a reactor vessel and a source of inert gas for purging the system. In a first state, the 4-way valve provides fluid communication between the reservoir and the reactor. In a second state, the 4-way valve provides a continuous circulation path for the heated reactants from the reservoir, to the valve system, and back to the reservoir via the return line. In a third state, the 4-way valve provides a fluid pathway for purging the reactor with inert gas. In a fourth state, the 4-way valve provides a fluid pathway for purging the reservoir with inert gas.

The invention provides a method for producing a peroxymonosulfuric acid solution with high stability, including the steps of mixing 35 mass % or more of hydrogen peroxide and 70 mass % or more of sulfuric acid to react them, cooling the reaction solution to 80 C. or lower within five minutes after initiation of the mixing step, and diluting the reaction solution with water four times or more as much as the reaction solution by mass.

A liquid fuel reformer includes a fuel vaporizer which utilizes heat from an upstream source of heat, specifically, an electric heater, operable in the start-up mode of the reformer, and therefore independent of the reforming reaction zone of the reformer, to vaporize fuel in a downstream vaporization zone.

A continuous mixer/reactor and a mixing process are provided in which materials flow in an orderly fashion along the length of a channel (9) and the materials are mixed in a direction transverse to the axis of the channel (9) by the provision of agitator elements (5, 7) within the channel (9) and shaking the channel (9) so that the agitator elements (5, 7) move within the channel (9) in the radial direction of the channel (9).

A continuous process for the manufacture of a polyamide, the process comprising the steps of: (i) flowing a stream A comprising a molten dicarboxylic acid, or a molten dicarboxylic acid-rich mixture comprising a dicarboxylic acid and a diamine, through a first stage and at least one more reaction stage of a vertical multistage reactor, wherein the first stage is at the top of the reactor; (ii) counter-currently flowing a stream B comprising a diamine as either a vapor or a diamine-rich liquid through at least one of the stages below the first reaction stage of said vertical multistage reactor; (iii) accumulating a liquid phase material P comprising polyamide at and/or below the final stage of said reactor; wherein said reactor is equipped with internal features suitable for effecting contact between counter-currently flowing streams A and B; and wherein said process further comprises the step of agitating said liquid phase material P by injecting a gaseous stream C comprising steam, or at least one inert gas, or a mixture of steam and at least one inert gas into the reactor at or below the final stage of the reactor. The invention further provides a vertical multistage reactor configured to implement said process.

The invention relates to a method of closed-loop control of the temperature in a chemical engineering apparatus (101, 201, 301, 401), in which, in a primary circuit (102, 202, 302, 402), a liquid is conveyed out of the apparatus (101, 201, 301, 401), fed at least partly to a heat transferer (103, 203, 303, 403) and recycled at least partly back to the apparatus (101, 201, 301, 401), where the heat transferer (103, 203, 303, 403) is cooled or heated by a heat transfer medium in a secondary circuit (104, 204, 304, 404), comprising the steps of: providing a target value for the temperature of the liquid in the apparatus (101, 201, 301, 401), detecting an actual value for the temperature of the liquid in the apparatus (101, 201, 301, 401) and calculating the temperature difference between the actual value and the target value of the liquid in the apparatus (101, 201, 301, 401).
According to the invention, a heat flow taken from or added to the liquid in the primary circuit (102, 202, 302, 402) by the heat transferer (103, 203, 303, 403) is ascertained, a control signal is calculated on the basis of a defined closed-loop control algorithm, where the closed-loop control algorithm is configured such that the control signal is dependent on the heat flow and the temperature difference between the actual value and the target value of the liquid in the apparatus (101, 201, 301, 401), and the flow rate of the stream of liquid through the heat transferer (103, 203, 303, 403) in the primary circuit (102, 202, 302, 402) and/or a flow rate of the heat transfer medium through the heat transferer in the secondary circuit (104, 204, 304, 404) is/are manipulated on the basis of the control signal.

A method for controlling lingerature of a chemical reaction. Changes in mass of a chemical reaction are monitored and are used to calculate a lingerature of the system. The reaction can be maintained at a desired lingerature () by selective addition or removal of heat or by adjusting the surface area the reactants are exposed to during the reaction. The disclosed method is useful for reactions that occur at non-equilibrium conditions where any measured lingerature would presume steady-state conditions.

A method for determining temperature information for a plurality of tubes in a furnace where one or more digital images provide temperature information for imaged tubes, and temperature information for non-imaged tubes is determined from the temperature information for the imaged tubes and measured temperatures of combined effluent from the imaged and non-imaged tubes.

A liquid fuel reformer (400) includes a fuel vaporizer (415) which utilizes heat from an upstream source of heat, specifically, an electric heater (406), operable in the start-up mode of the reformer (400), and therefore independent of the reforming reaction zone of the reformer, to vaporize fuel in a downstream vaporization zone.

Systems and methods for detecting coking in a wash bed of a vacuum pipe still with a sensing cable including an optical fiber sensor array aligned with a heating element disposed in the vessel. An optical signal interrogator is configured to measure a first temperature profile at a plurality of sensor locations to determine a flow distribution. An excitation source is configured to propagate at least one heat pulse through the heating element and the optical signal interrogator is configured to measure a second temperature profile corresponding to the heat pulse at the sensor locations. A control unit is configured to detect coking by determining one or more properties of the media exposed to the sensing cable at each of the plurality of sensor locations based on the second temperature profile corresponding thereto.