SU980745A1 - Multi-chamber heat-and-mass exchange apparatus - Google Patents

Description

(54) MULTI-CHAMBER HEAT AND MASS EXCHANGE EQUIPMENT

one

The invention relates to apparatus for carrying out heat and mass transfer processes, and more specifically to mass transfer columns for gas-to-liquid systems.

A multi-dimensional, mass-exchange apparatus is known, comprising a housing with nozzles for input and output of phases with contact stages, comprising a turbulence device, a separator, drain pipes and a droplet separator 1.

The disadvantages of this apparatus are that the organization of the foam layer in it is carried out in such a way that the apparatus is large and the gas flow energy is not fully utilized. In the apparatus, a foam layer is formed in the contact tube, i.e., in the part of the body located between the structural steps. The size of this part (contact tube) depends on the height of the foam layer, which is necessary for normal operation of the apparatus. In turn, the height of the foam layer depends on many factors, such as gas velocity, the physical properties of the fluid, and others. The gas flow rate can be increased only to a certain value, after

which greatly increases the kapleunos and the size of the apparatus.

In such devices, the height of the foam layer is 200-600 mm at a speed of 2-7.5 m / s, and the height of the columns reaches 3 meters or more. Due to the presence of the axial velocity component, the energy of the gas flow is not fully utilized to break up the liquid and to spin the gas-liquid flow. Due to this, the droplet sizes are larger, and the contact surface of the phases and the productivity of the apparatus are smaller.

The purpose of the invention is to increase productivity by intensifying heat and mass transfer processes and reducing the size of the apparatus due to the complete use of the energy of the gas stream.

This goal is achieved by the fact that in a multi-chamber heat and mass transfer apparatus, including a housing with nozzles for input and output of phases with contact stages, containing a swirling device, a separator, a drain pipe and a droplet separator, the contact stage is provided with a central nozzle, mesh cylinder and suction pipe, the end the latter is located in the central zone of the contact stage, the lower part of which is enclosed by a cone-shaped tray with a drain pipe forming an annular channel with the contact stage chi gas, wherein the drain pipe is placed on top of the underlying stage, while the central pipe is connected to the annular channel overlying level. It is advisable to perform the contact stage extended in the central part. The drawing shows a multi-chamber heat and mass transfer apparatus, a longitudinal section. The multi-chamber heat and mass transfer apparatus consists of separate structural steps, which are made in the form of vortex chambers, one above the other. The first stage 1, in the course of the gas movement in the lower part, is provided with a receiving chamber 2 with a pipe 3 for supplying gas and a pipe 4 for draining the liquid. The last stage 5, located at the top of the column, has a pipe 6 for supplying liquid. Above it is a drop separator 7 with a nozzle 8 for the discharge of gas. Each vortex chamber is formed by a shell 9, an upper profiled lid 10: transition into the central nozzle 11 and a cone 12 located in the lower part of the chamber. Inside the casing 12 there is a cone-shaped pan 13, fitted with a drain pipe 14, the lower end of which is included in the central zone of the underlying vortex chamber. An annular channel 15 is formed between the cone 12 and the cone-shaped tray 13. A guide vane 16 with tangential slots and a rotating disk 17 with blades 18 is placed in the vortex chamber. The lower part of the suction tube 19 of the nozzle 1 inside which the cylinder is mounted 20 of the grid. The central nozzle 11 with a cylinder 20 and a suction tube 19 serves as a separator. An annular pocket 21 is formed between the nozzle 11 and the cylinder 20. The structural steps are fixed to each other by means of flanges 22. The apparatus works as follows. Gas is introduced into the receiving chamber 2 through the nozzle 3 and through the annular channel 15 uniformly flows to the guide apparatus 16. Next, the gas enters the working zone of the vortex chamber through the tangential slots of the guide apparatus 16. The passage with great speed through the cracks, it acquires a rotational motion. Due to the energy of the moving gas, the disk 17c is twisted with blades 18. A liquid enters the disk 17 from the leaching stage through the discharge pipe 14, which is thrown into the working zone of the chamber by the action of centrifugal forces. The gas at the exit from the slots splits the liquid into small droplets and draws them into a joint rotational movement, forming a rotating gas-liquid ring. As a result, continuous surface renewal is provided, the contact time of the phases increases, and, consequently, heat and mass transfer processes proceed intensively. The excess liquid flows into the cone-shaped tray 13 and through the drain pipe 14 enters the disk of the underlying stage. The swirling gas-liquid mixture rises along the upper profiled lid 10, with large droplets and liquid films flowing down it. Some of the droplets are discarded with the help of vanes 18. Then the gas, continuing to rotate, passes through the separator. Liquid droplets by centrifugal forces are dropped to the periphery, pass through the grid cells of the cylinder 20 and fall into the annular pocket 21, from where liquid and gas that has slipped through the grid cells return to the chamber along the suction pipe 19, since the end of the tube is placed in the central zone of the chamber where the discharge is created. Separated from the liquid and evenly distributed, the gas flows through the annular channel 15 to the next-stage guide apparatus. The rotation of the gas does not stop all the time, therefore, having passed through the tangential slots of the guide vane, the gas receives an additional twist and enters the working area. Thus, the energy of the gas-liquid flow is not completely quenched at the stage, i.e. it is used more fully. Thus, the process is repeated at each step. After the last upper stage 5, before leaving the column, the gas passes through the drop separator 7 and purified through the pipe 8 is removed from the apparatus. Unlike other stages, the upper stage 5 receives liquid through pipe 6, and from the lower one liquid is removed from the device through pipe 4. The proposed multi-chamber heat and mass transfer device has several advantages over the known one. The main factor is that the design allows it to increase the gas-liquid flow rate, which is impossible to do in the known multistage columns without increasing the size of the apparatus, since the liquid entrainment of the gas flow from the underlying to the overlying steps increases. When organizing a rotating dynamic foam layer in the proposed apparatus, the energy of the gas flow is used more fully, since the axial component of the velocity is minimal. It is known that the higher the gas velocity, the liquid is crushed into smaller particles, which means that the contact surface of the phases increases, and the processes of heat and mass transfer take place more intensively. In multistage columns, it is important to ensure separation at each stage, which makes it possible to reduce sprinkling and increase the velocity of the gaseous medium.

In the proposed apparatus, the separation of fluid occurs in several stages. After the phases interact, the gas-liquid mixture moves upward, with large droplets and liquid films being thrown to the profiled wall and flowing down it into the working area, liquid particles also beating off the blades, and the gas enters the separation part, where the droplets through the grid cells slip into the annular pocket and retraction with a suction tube. As a result, good conditions are created for carrying out various mass transfer processes. It is also important that the number of steps in a column can be changed depending on the processes carried out and the interacting substances, since it consists of a set of structural steps that are easily disassembled and assembled. The device is easy to operate, has small dimensions with high performance.

The dimensions of the proposed apparatus are several times smaller than the known columns. This is due to the fact that the height of the rotating foam layer in this apparatus is very small and is on the same level as the swirling guide apparatus. According to the experiment, the optimum layer height is 20 mm. In the known column, a foam layer is formed above the scooping device and reaches 200-600 mm.

A prototype of a multi-chamber heat exchanger was tested in the “Energokhimmash” SCR and gave good results. With the same performance of the known and proposed experimental apparatus, the metal intensity of the latter is reduced by 4 times. The apparatus is intended to produce formaldehyde. Perhaps its use in other chemical processes. Upon receipt of formaldehyde due to the intensification of the gas absorption process, the loss (by industry) of formaldehyde is reduced by 1,400 tons / g and methanol by 2,500 tons / g (according to the data of the Novosibirsk branch of KNPO Karbolit). With the cost of formaldehyde B5 78 p; g and methanol 40-50 p / g, the annual economy is 1400-65 + 2500-40 191000 p. 0

Claims (2)

1. Multichamber heat and mass transfer apparatus, including a housing with connections J for input and output of phases with contact stages, containing a vortex device, separator, drain pipes and a droplet separator, characterized in that, in order to intensify heat and mass transfer and reduce dimensions due to the complete use of gas flow energy, the contact stage is provided with a central pipe with mesh cylinder and suction pipe, the end of the latter is located in the central zone of the contact stage, the lower part of which is provided with a conical  a tray with a drain pipe forming an annular gas supply channel with the contact stage, with the drain pipe located in the upper part of the lower stage and the central nozzle connected to the annular channel of the upper stage. 2. The apparatus according to claim 1, characterized in that the contact stage is made mounted in the central part. Sources of information taken into account in the examination 1- Bogatykh S. А. Cyclone-foamy apparatuses. L., “Machining Engineering, 1978, p. 25