SU747483A1 - Mass exchange apparatus - Google Patents

Description

(54) MASS EXCHANGE DEVICE

I

The invention relates to the instrumentation of the processes of petrochemical, chemical, etc. technology, implemented on heterogeneous systems liquid-gas, liquid-liquid-gas, etc., and can be used in petrochemistry.

A known apparatus for conducting mass-exchange processes in a heterogeneous gas-slurry system, made in the form of a vertical column, in which gas distribution devices are installed at a distance from each other along the height of the apparatus, re-Q dispersed the gas phase. Each of the gas distributing devices is assembled from two hollow truncated cones, the large bases of which are tightly attached to the wall of the column, and the truncated tops (the smaller bases) are tightly connected to the 15 plate, perforated with holes and between them l.

In the known apparatus, the volume enclosed between the outer surfaces of the truncated hollow conical inserts and the inner surface of the column is excluded from the reaction volume. In addition, ensuring tightness at the joints of large bases of tapered inserts with the body of the apparatus complicates the design of the apparatus and its installation.

A mass-exchange apparatus is also known, which includes a vertical cylindrical body with a lid and a bottom, large and small truncated cones along the axis of the body, which are directed smaller towards each other with smaller bases and annular gaps, bubblers and fittings 2 from the body.

The known apparatus has the following disadvantages.

Claims (2)

At the exit of gas bubbles through the truncated apex of the larger cone insert, an uneven distribution of gas is observed over the area of the truncated apex of the cone insert. Gas bubbles are more concentrated near the circumference of the truncated apex and to a lesser extent along the axis of the apparatus. A similar phenomenon occurs at the exit of the gas phase from the annular gap formed by the wall of the column and a large base of a smaller conical insert. In this case, the concentration of gas bubbles near the circumference of the base of the insert is greater than that of the walls of the apparatus. Moreover, with an increase in the diameter of the apparatus, this effect is enhanced. Since industrial columns can have a diameter of up to 10 m, in such devices the uneven distribution of the gas phase in these zones can be quite significant. The latter leads to a weakening of the circulation movement in the zones between the inserts, to an increase in the tightness of gas bubbles, contributing to an increase in their size and, accordingly, leading to a decrease in the interfacial surface. All this contributes to the fall of the volume coefficients of mass transfer. In order to increase volumetric mass transfer coefficients, the device is equipped with perforated horizontal disks fixed on smaller bases of large truncated cones, and rings fixed between the case and large bases of small truncated cones, and additionally the device is equipped with rings installed under the disks and rings. plates, dividing them into sector cells. FIG. 1 shows a longitudinal section of a general view of the apparatus; in fig. 2 — node A in FIG. one; in fig. 3 - node B in FIG. 1. The apparatus consists of a cylindrical body 1, a lid 2 and a bottom 3, bubblers 4, fittings 5, metal rods (pipes) 6, on which the copuses 7 of the perforated rings 8 and disks 9 are fixed, which cover smaller tops of the cones 7. For even gas distribution under the rings and discs; their area is divided into sector cells using plates 10, installed perpendicularly and hermetically to the lateral surfaces of the truncated hollow cones and to the surface of the rings and discs. The device works as follows. Gas bubbles dispersed into the liquid by the bubbler 4, lifting up, collect the inner side surface of the larger cone 7 under the disk 9. The latter occurs mainly due to the fact that the area of the annular gap at the cone is much smaller than the area of its smaller apex, and the cone itself is tilted by the top way down. As a result, a gas cushion is formed under the disk, from where the gas, the passage through the holes in the disk, is redispersed into the next zone. Since the disc diameter is smaller than the diameter of the body, an uneven distribution of bubbles over the cross section of the apparatus is created behind it, which leads to the appearance of an intense fluid circulation. Gas bubbles, foray into the truncated apex of a small cone, are deflected against the wall of the column and are collected under the ring 8. After redispersing the gas through the ring holes, gas bubbles are relatively evenly distributed over it, but their concentration in the central part of the column cross-section is much less. This causes intensive circulation of fluid, but with a reverse direction than in the previous zone. As a result, a part of the liquid, skipping through the disk 9 into the underlying zone, contributes to an additional deviation of bubbles in this zone towards the wall of the column. The bubbles are then collected again under the disk. Thus, the redispersion process is periodically repeated, then through the disk, then through the rings. In the case of the installation of plates, a more uniform distribution of gas under the disks and rings is observed, and, accordingly, its more uniform redispersion through all their openings. The proposed apparatus allows for periodic redispersion of the gas phase through the orifices and due to the relatively even distribution of the bubbles in the required cross sections of the column, which eliminates the local constraint of the bubbles. as is the case in apparatus with conical inserts without discs, to achieve an increase in the volume coefficients of mass transfer. In addition, the installation of disks and rings makes it possible to more strictly separate one zone of mixing from another, and thereby further reduce longitudinal mixing along the height of the apparatus. When using the proposed apparatus, for example, in the process of isopropylbenzene oxidation in the production of phenol-acetogene by the cumene method, an increase in the oxidation reaction rate g by a factor of 1.2 and an increase in the selectivity of the process by 2 are expected. Formula 1: A mass transfer apparatus including a vertical cylindrical body with a lid and a bottom, large and small truncated cones located along the axis of the body and directed smaller towards each other, bubblers and fittings, distinguishing in that in order to increase the volumetric mass transfer coefficient, by increasing the contact surface is provided with a horizontal perforated disc fixed to the base mensche x larger truncated cones and rings secured between the housing and bolschoy .malyh bases of truncated cones. 2. A mass transfer apparatus according to claim 1, characterized in that it is provided with radial plates mounted under the discs and rings. Sources of information taken into account in the examination of 1.Patent Czechoslovakia No. 88401, cl. 12 g 1/01. 2. USSR author's certificate for application No. 2527120, 1977 (prototype). Phi-g. / Uiel A Fi, .b