SU997788A1 - Reactor for oxidizing hydrocarbons - Google Patents

Description

tori during repairs and emergency situations. Deposition of tar leads to their blockage. This complicates the drainage of reactors during planned shutdowns for repair and cleaning and virtually eliminates the possibility of drainage when creating emergency situations, which reduces the safety of operation of the reactor.

A hydrocarbon oxidation reactor is also known, comprising a cylindrical body, baffles installed in height upward as part of a sphere, dividing the body into sections, fittings for inlet and outlet of liquid, bubblers for supplying oxygen-containing gas to each section, flow-through gas pipes serving as removing the reaction gases, and ujTyuep to exit the reaction gases 2.

 The disadvantage of this reactor is the lack of efficiency of the process and the reliability of the apparatus due to the deposition of stop-like products on the bottom and walls and the high oxygen concentration in the exhaust gases.

Closest to the invention is a hydrocarbon oxidation reactor, comprising a body with spherical horizontal partitions, gas valves, a gas supply barometer and gas overflow pipes, additionally equipped with a ring collector connected to the liquid hydrocarbon inlet pipe with vertical, cornered tubes, with nozzles located below the bubbler plane between the side wall of the reactor and the bubbler ring, and the overflow pockets for the flow of fluid, the upper end of which is located below the collector, and also connected to the upper part of the liquid hydrocarbon inlet pipe by a vapor pipe, the lower end of which is located below the upper edge of the overflow pocket and above the plane of the bubblers.

Due to the equipment, the stirring of the reaction mass is intensified, as a result of which the efficiency of the reactor increases, the safety of the process Z is improved.

However, the known device is specific to the design of reactors with partitions curved upwards as part of a sphere and does not solve problems for reactors with elliptical bottoms. One nozzle ring does not provide a sufficient degree of mixing in an elliptical bottom reactor, especially in the central zone. The problem of preventing the resinous products from draining the drain pipe located in the center of the elliptical bottom is not solved. Moreover, the device is rather cumbersome and metal consuming. Great perimeter

ring collector and the length of the tubes descending from it to the bottom of the reactor. At the same time, elliptical-bottom reactors are widely distributed in industry.

The aim of the invention is to increase the efficiency of the process by preventing the deposition of resinous reaction products in the lower part of the reactor and reducing the oxygen concentration in the exhaust reaction gases, as well as ensuring the possibility of drainage during repairs and emergency situations.

The goal is achieved by the fact that in a reactor for oxidizing hydrocarbons containing a cylindrical body, fittings for inlet and outlet of a liquid, bubblers for supplying oxygen-containing gas, a fitting for discharging reaction gases connected to the inlet of a liquid hydrocarbon, a manifold fitted with tubes made with nozzles located below the plane of the bubblers, overflow pocket for drainage. the liquid connected to the upper part of the liquid hydrocarbon inlet pipe, the vapor pipe, the lower end of which is located below the upper edge of the overflow pocket and above the bubbler plane, the collector tubes, whose length decreases along the bottom of the apparatus, are located horizontally in the lower part of the manifold vertically, the collector is provided with a nozzle installed at its lower end, and the nozzle section of each tube is proportional to its distance. from the axis of the reactor and is determined by the following dependence

.R, where / Rp-,

at the same time S - pls tsadd nozzle section

tubes;

n is the distance from the nozzle to the reactor axis.

Figure 1 shows the reactor section; figure 2 - section aa in figure 1; Fig. 3 is a view B of Fig. 1 (the end of the bent tube, ending with a nozzle).

The reactor is a vertical cylindrical apparatus containing a cylindrical body 1, upper 2 and lower 3 elliptical bottoms, fittings for introducing liquid hydrocarbon 4 and oxygen-containing gas (air) 5, for withdrawing oxidate 6 and reactive gases 7, fitting 8 for draining. The fitting 4 for introducing the liquid hydrocarbon is closed by the distribution box 9. From the box 9, a collector 10 extends to the bottom of the reactor, the lower end of which is lowered below the plane of the bubblers 11 and 12. From the collector 10, below the plane of the bubblers 11 and 12, go horizontally to several rows of tube 13-15, the length of which decreases towards the bottom of the apparatus. Tubes 13-15 are bent at the ends tangentially to the wall of the reactor and terminate at nozzles 16-18. A collector 10 at the bottom end is provided with a nozzle 19 directed vertically downwards. For example, a reactor is shown with three rows of horizontal tubes with nozzles and with five tubes in each pipe. Oxygenated gas for oxidation through the nozzle, 5 and the distribution comb 20 is fed into the rings of the bubblers 11 and 12 and through the working and drainage holes of the bubblers enters the bubbling layer. The oxydate from the overflow pocket 21 through the nozzle b is transferred from the reactor to the next / cascade reactor or for further processing. Distribution duct 9. In the upper part, it is equipped with a vent tube 22, which serves to discharge gases that are separated from the liquid. The proposed reactor operates as follows. Liquid hydrocarbon (cyclohexane) through nozzle 4, duct 9, manifold 10 and tubes 13-1 with nozzles 16-18. Enters the lower part of the reactor under the plane of spreading of the bubblers 11 and 12. Tubes 13-15 are made bent around the perimeter of the reactor vessel wall (Fig. 1-3), and at the ends of these tubes there are nozzles 16-18, the diameter of which is correspondingly smaller than the diameter of tubes 13-15. Due to this technical solution, the liquid is pulled out of the nozzles tangentially to the wall of the reactor at high speed and, twisting, greatly enhances the mixing in the entire volume of the zone between the bubbler location plane and the lower elliptical bottom 3. Leaving from. A nozzle 19 installed at the lower end of the collector 10 vertically downwards a jet of liquid washes the center of the elliptical bottom, additionally intensifies mixing and prevents clogging of the drainage pipe. In addition, the nozzle 19 provides complete drainage of the collector 10 and tubes 13-15 when it stops. The enhanced mixing in the lower zone extends to the rest of the remaining reaction volume. This leads to a more complete use of the reaction volume for the oxidation reaction, an increase in reactor productivity, an intensification of the oxidation process itself, leading to a decrease in the oxygen concentration in the reaction gases at the outlet of the reactor, an increase in the safety of the reactor, due to the fact that the bottom of the reactor, the liquid washes the lower elliptical bottom and the adjacent walls of the reactor, thereby preventing the deposition of tar-like reaction products and the accumulation of x on the bottom and with Tanks of the vessel Oxygen-containing gas is fed into the reactor through fitting 5, and through the annular bubblers 11 and 12 enters the bubbling bed. Oxidate through overflow pocket 21 and nozzle 6 is withdrawn in the cascade reactor or for further processing. The reaction gases are discharged through the nozzle for the most efficient management. The process requires that all the kinetic energy of the liquid supplied to the lower part of the reactor is spent on mixing. The ingress of gas into the source hydrocarbon can lead to rupture and thus to a decrease in the energy of the jets emerging from the nozzles 16, 17 and 19. To prevent this, in the upper part of the distribution box 9 there is an exhaust pipe 22 serving to drain gas from the liquid hydrocarbon supplied through the collector 10 and pipes 13-15 to the nozzles 16, 17 and 19. The lower end of the exhaust pipe 22 is placed in the gas-liquid layer below the upper the edges of the overflow pocket 21 and above the position of the bubblers are 11 and 12. This ensures the free flow of gases from the distribution box 9 and prevents them from entering the collector 10 and the pipes 13-15. In addition, due to the proposed technical solution, a small amount of the source hydrocarbon entrained with the separated gases enters the zone of the most intense reaction and cannot slip into the sleeping pocket, mine reaction zone. The presence of a collector and horizontal collector tubes with liquid hydrocarbon feed nozzles located between the plane of the annular bubblers and the elliptical bottom allows intensification of mixing in the lower zone and throughout the reactor volume, which allows increasing the efficiency of the oxidation process and reducing the oxygen concentration in the reaction gas at the outlet of the reactor prevents the deposition and accumulation of resinous products on the bottom, walls and internal parts of the reactor, which increases the safety of the the process of oxidation. The presence of a nozzle at the bottom end of the collector allows for further intensification of mixing in the bottom part of the reaction volume and provides complete hydrocarbon drainage when the reactor is stopped for repair or in the event of an emergency.

The implementation of the collector in the form of a descending station allows to significantly reduce the metal consumption of the structure.

Laboratory tests of the proposed design, using the example of catalytic oxidation of sodium sulfite with oxygen in air at a velocity of liquid in the nozzles of 6-8 m / s, are given in the table.

It can be seen from the table that, compared with the known design, the oxygen concentration in the exhaust gases in the optimal case decreased from 16.2 to 12.1% by volume. Thus, the degree of utilization of oxygen and the removal of products with the same air flow rate and the same reactor volume increase.

Claims (3)

Known 1 Proposed Claim 1. Hydrocarbon oxidation reactor containing cylindrical body, fittings for liquid inlet and outlet, bubblers for oxygen gas containing gas, gas outlet for reaction gases connected to hydrocarbon inlet, collector fitted with tubes made with nozzles located below the plane of the bubblers, a pouring pocket for the flow of fluid, connected to the upper part of the nozzle of the liquid hydrocarbon inlet Below the upper edge of the overflow pocket and the above-plane of the bubblers, I differ from the fact that, in order to improve the efficiency of the process by preventing the formation of tar-like reaction products in the lower part of the reactor and reducing the oxygen concentration in the off-reaction gases The collector tubes, the length of which decreases towards the bottom of the apparatus, are located horizontally in the lower part of the manifold spaced vertically. 16.2 -2. The reactor in accordance with claim 1, characterized in that, in order to allow drainage during repairs and emergency situations, the collector is provided with a nozzle installed at its lower end. 3. Reactor pop.1, otlinyayuts and the fact that the nozzle section of each tube is proportional to its distance from the axis of the reactor and is determined by the following relationship: where,,, and 3 is the nozzle section of the pipe; K is the distance from the nozzle to the reactor axis. Sources of information taken into account in the examination, 1.Patent of France No. 1595542, class, 01 J, 1970. 2. Authors certificate of the USSR 791406, cl. On 10/00, 1980. 3. USSR author's certificate for application number 3218540 / 23-26, cl. On 01 J 10/00, 1980.