SU667215A1 - Gas-lift heat-mass-exchange apparatus - Google Patents

Description

(54) GASLIFT HEAT AND MASS EXCHANGE APPARATUS

I

The invention relates to apparatus for use in the chemical, petrochemical, and other industries of the industry for carrying out heat and mass transfer processes, in particular for the preparation of an alcohol-air mixture in formalin production.

An apparatus is known in which in order to intensify circulation and heat and mass transfer a directional airlift is used, which does not allow for one important condition: to obtain a homogeneous alcohol-free mixture not containing a drop of alcohol suitable for the catalytic oxidation of alcohol to formaldehyde 1.

Apparatuses for preparing an alcohol-air mixture are known, for example, in the production of formalin.

The evaporator consists of a housing, inside which is placed a fender and gas distribution device with a central pipe for air intake, overflow pipes embedded in an umbrella, fittings for injecting an alcohol mixture, air and outputting an alcohol-air mixture 2.

The described apparatus does not provide a high-quality process of preparing an alcohol-air mixture, since the process of mass and heat transfer between the alcohol mixture and air occurs slowly due to the excessively low circulation of the mass of liquid inside the apparatus. As a result of this, the alcohol drops are carried away from the apparatus, get onto the catalyst, and the alcohol oxidation process is quenched.

The aim of the invention is to intensify the internal circulation of a mass of fluid and heat and mass transfer.

The goal is achieved by the fact that the casing of the proposed apparatus is provided with a hollow cylinder with double walls, perforated from the inner wall, in the upper part of which longitudinal partitions are installed. A coil is mounted in the lower part of the device. The interstitial space of the hollow cylinder is connected to the gas phase inlet fitting. To evenly distribute the air flow around the cylinder, the openings on the inner wall of the cylinder are made of different sections — large in the lower part and smaller — in the upper one.

Claims (2)

The proposed device is shown in the drawing. Inside the housing 1 there is a breaker device 2 with a water seal 3 and a gas distribution device consisting of a hollow cylinder 4 with perforations made on its inner surface and of two pipes 5 connecting the hollow cylinder with the air supply pipe 6 to the apparatus. In the upper part of the hollow cylinder 4 times1, the longitudinal plates 7 are still, and a cone reflector 8 is attached to the pipes 5. The hollow cylinder 4 is attached to the body 1 of the apparatus by four plates 9. At the bottom, below the hollow cylinder 4, there is a coil 10, equipped with fittings II and 12 for removal and supply of coolant. The device is also equipped with fittings: 13 - for feeding the original alcohol mixture, 14 - for circulating the alcohol mixture in the subcooled heat exchanger 15 - for leaving the alcohol-air mixture out of the device, 16 - for manovacuummeter, for installing temperature sensors in the liquid and gas zones of the device, 18 - for installation of the gage. To evenly distribute the air passing through the perforations of the inner surface of the hollow cylinder, the sizes of the holes are made of varying diameter, increasing them in the lower part and decreasing them in the upper part of the hollow cylinder. Plates 7 are designed to breakdown large air bubbles in the air-fluid airlift. The device works as follows. Through fitting 13, a water-alcohol mixture is continuously supplied to the apparatus, the amount of which is controlled by a level gauge with a command to the control actuating valve installed on the supply line of the water-alcohol mixture to the apparatus. Through fitting 14, the water-alcohol mixture is pumped into the annular space of the heat exchanger of the contact apparatus, it takes the heat of reaction, heats up and enters the apparatus again. Through pipe 6, air is forced into the annular space of the cylinder 4, which, having passed through the cylinder holes, enters the fluid layer and, lifting up, forms an air-lift. The high velocity alcohol – air mixture hits the reflector 8 and descends between the wall of the apparatus body and the outer wall of the hollow cylinder, forming a closed internal circulation loop. Plates 7, breaking large air bubbles, promote intensive homogenization of the mixture, eliminate vibration, hydraulic shocks and pulsation of alcohol-air flow. Intensive internal circulation contributes to the improvement of heat and mass transfer and the preparation of a good-quality alcohol-air mixture, which through outlet 15 leaves the apparatus. If it is necessary to quickly change the temperature of the alcohol-air mixture (for technological reasons.), An additional ball is introduced through the fitting 11 into the coil. Thus, in the proposed device, the rate of circulation and heat and mass transfer is significantly increased; an effective homogenization of the phases of the liquid — gas due to the multiple circulation of these phases inside the hollow cylinder and the crushing of coarse particles occurs5; air bubbles when hitting longitudinal plates. In addition, the presence of a coil that is not connected with the contact apparatus allows one to regulate the intensity of the heat and mass transfer process. Claim 1. Gas-lift heat and mass transfer apparatus for mixing gas with liquid and evaporation of a mixture, including a housing, a fender and gas-distributing device, nozzles for entering phases and extracting an air mixture, characterized in that, in order to intensify circulation and heat and mass transfer, the housing is equipped a hollow cylinder, with double walls, perforated on the side of the inner wall, in the upper part of which longitudinal partitions are installed, in the lower part of the coil, and the interstitial space of the hollow cylinder is connected to a fitting for introducing a gaseous phase. 2. An apparatus according to claim 1, characterized in that, in order to evenly distribute the air flow inside the cylinder, the openings on the inner wall of the cylinder are made of different sections — large in the lower part and smaller — in the upper one. Sources of information taken into account during the examination 1. USSR author's certificate No. 129899, cl. B 01 D 3/32. 2. "Equipment, its operation, repair and protection of corrosion in chemical industry, abstract collection NIIGEHIM, M., 1976, No. 7, p. one.