Method for maximizing the reaction volume in a slurry phase reactor by determining the ratio (f) between the height of the foams (H.sub.f) and the height of the reactor (H.sub.R) through an algorithm defining the gas hold-up in three zones, a first lower zone in which a bubble regime is established, a second intermediate zone where there can be the presence of foams, a third zone situated in the upper hemispherical part in which the multiphase mixture is accelerated until it reaches outlet conditions, the average gas hold-up being given by the weighted average of each of the three gas hold-ups of the three zones, characterized in that it uses nuclear densimeters positioned inside the reactor at different heights and comprises: measuring, for each nuclear densimeter used, gas density values, relating to different gas and/or slurry velocities, which correspond through said algorithm to calculated gas hold-up values, revealing, with a calculated gas hold-up of less than 40%, the absence of foams at least up to the height at which the densimeter is positioned, whose density measured corresponds to said gas hold-up, with a calculated gas hold-up higher than 70%, the presence of foams starting at least from the height of the reactor in which the densimeter is positioned, whose density measured corresponds to said gas hold-up, finally, determining through said algorithm, the ratio f and the extension in height of the possible presence of foams, calculating the consequent height H.sub.f.

A process for production of C.sub.4 to C.sub.15 esters by the esterification of a carboxylic acid or anhydride with a C.sub.4 to C.sub.15 alcohol including forming a reaction mixture of the acid or anhydride and the C.sub.4 to C.sub.15 alcohol including a stoichiometric excess of the alcohol is provided.

A reactor for performing a gas/liquid biphasic high-pressure reaction with a foaming medium, comprising an interior formed by a cylindrical, vertically oriented elongate shell, a bottom and a cap, wherein the interior is divided by internals into a backmixed zone and a zone of limited backmixing, wherein the backmixed zone and the zone of limited backmixing are consecutively traversable by the reaction mixture, wherein the backmixed zone comprises means for introducing gas and liquid and a gas outlet and also comprises at least one mixing apparatus selected from a stirrer, a jet nozzle and means for injecting the gas, and the zone of limited backmixing comprises a reaction product outlet, a first cylindrical internal element which in the interior extends in the longitudinal direction of the reactor and which delimits the zone of limited backmixing from the backmixed zone, backmixing-preventing second internal elements in the form of random packings, structured packings or liquid-permeable trays arranged in the zone of limited backmixing and a riser tube whose lower end is arranged within the backmixed zone and whose upper end opens into the zone of limited backmixing so that liquid from the backmixed zone can ascend into the zone of limited backmixing via the riser tube, wherein flow into the zone of limited backmixing enters from below. The reactor is configured such that the high-pressure reaction space is optimally utilized and contamination of workup steps or subsequent reactions arranged downstream of the high-pressure reaction with foam is substantially avoided. The invention further relates to a process for performing a continuous gas/liquid biphasic high-pressure reaction in the reactor.

A foam sensor device is used for monitoring foam within a vessel. The sensor (e.g. accelerometer) is encapsulated inside a water-tight, sterilizable, shell, which floats on a liquid contained. In one example, the foam sensor device includes an accelerometer for detecting and measuring rotation and movement of the foam sensor device and generates movement data based on the detected movement. During a learning or calibration process, sensor data (e.g., movement data) from the foam sensor device is analyzed and classified using machine learning and/or signal processing methods to extract features indicative of different possible foam statuses, including varying levels of foam, or no foam and generate models for the different statuses. During normal operation, the foam sensor device transmits sensor data to an analyzer containing the pre-calibrated models, which determines whether there is foam or not. Based on the foam status, a pump controller adds anti-foam solution.

Disclosed is a process for making a polyetheramine containing polyamide without excessive foaming in successive batches by providing a controlled heat input rate step for those batch runs that incorporate polyetheramine containing polyamide heel from previous runs.

The present invention relates to a method of preparing a vinyl chloride-based polymer, which may prepare a vinyl chloride-based polymer with excellent surface properties by adjusting a foam level generated during a polymerization reaction to an appropriate value, a vinyl chloride-based polymer prepared thereby, and an apparatus for preparing a vinyl chloride-based polymer which may prepare the vinyl chloride-based polymer. The method of preparing a vinyl chloride-based polymer according to the present invention may prepare a vinyl chloride-based polymer with excellent surface properties, for example, fewer occurrences of fish-eyes and excellent transparency, by performing a polymerization reaction while maintaining the level of a foam generated during the polymerization reaction at an appropriate value.

A reactor for performing a gas/liquid biphasic high-pressure reaction with a foaming medium, comprising an interior formed by a cylindrical, vertically oriented elongate shell, a bottom and a cap, wherein the interior is divided by internals into a backmixed zone and a zone of limited backmixing, wherein the backmixed zone and the zone of limited backmixing are consecutively traversable by the reaction mixture, wherein the backmixed zone comprises means for introducing gas and liquid and a gas outlet and also comprises at least one mixing apparatus selected from a stirrer, a jet nozzle and means for injecting the gas, and the zone of limited backmixing comprises a reaction product outlet, a first cylindrical internal element which in the interior extends in the longitudinal direction of the reactor and which delimits the zone of limited backmixing from the backmixed zone, backmixing-preventing second internal elements in the form of random packings, structured packings or liquid-permeable trays arranged in the zone of limited backmixing and a riser tube whose lower end is arranged within the backmixed zone and whose upper end opens into the zone of limited backmixing so that liquid from the backmixed zone can ascend into the zone of limited backmixing via the riser tube, wherein flow into the zone of limited backmixing enters from below. The reactor is configured such that the high-pressure reaction space is optimally utilized and contamination of workup steps or subsequent reactions arranged downstream of the high-pressure reaction with foam is substantially avoided. The invention further relates to a process for performing a continuous gas/liquid biphasic high-pressure reaction in the reactor.

The present invention relates to a post-processing apparatus configured to post-process latex, the post-processing apparatus including: a receiving tank having therein a receiving part and having an inlet port through which the latex is introduced into the receiving part and a discharge port through which the latex is discharged; an ultrasonic wave generating device configured to generate ultrasonic waves to the latex accommodated in the receiving tank; a pressure reducing part configured to reduce a pressure of the receiving part of the receiving tank to discharge an unreacted monomer to the outside of the receiving tank; and a partition part provided in the receiving part of the receiving tank and comprising a plurality of partitions disposed in a direction from the inlet port toward the discharge port of the receiving tank, in which the latex accommodated in the receiving part moves along upper and lower sides of the plurality of partitions.

Disclosed is a process for making a polyetheramine containing polyamide without excessive foaming in successive batches by providing a controlled heat input rate step for those batch runs that incorporate polyetheramine containing polyamide heel from previous runs.

The present invention relates to a method of preparing a vinyl chloride-based polymer, which may prepare a vinyl chloride-based polymer with excellent surface properties by adjusting a foam level generated during a polymerization reaction to an appropriate value, a vinyl chloride-based polymer prepared thereby, and an apparatus for preparing a vinyl chloride-based polymer which may prepare the vinyl chloride-based polymer. The method of preparing a vinyl chloride-based polymer according to the present invention may prepare a vinyl chloride-based polymer with excellent surface properties, for example, fewer occurrences of fish-eyes and excellent transparency, by performing a polymerization reaction while maintaining the level of a foam generated during the polymerization reaction at an appropriate value.