RU2559496C1 - Heat exchanger - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to chemical, petrochemical, power, pharmaceutical and food industries. Heat exchanger comprises case (1) with fluid and gas feed and discharge pipes, revolving drum (3) with radial blades (6) arranged in said case, said blades being arranged on inner surface over the drum entire length. Drum (3) has solid sidewall and end covers with radial forces arranged around the shaft for gas and fluid passage. Radial blades are made of sheet material and composed of sheet different-width bent parts while holes in the drum end covers do not overlap the blades end parts.

EFFECT: reduced fluid droplet entrainment, hence, higher efficiency of heat exchange processes in gas-fluid system.

3 cl, 4 dwg

Description

The invention is intended for carrying out heat and mass transfer processes in a gas-liquid system and can find application in the chemical, petrochemical, metallurgical, energy, pharmaceutical and food industries.

Known rotor-film heat and mass transfer apparatus, comprising a housing with inlet and outlet air nozzles and a rotor with a drive located in the housing, consisting of flat, parallel mounted disks mounted on a horizontal shaft, and a heat and mass transfer working chamber with an inlet pressure port, the lower part of which filled with liquid into which the disks are immersed, the chamber being provided with a dividing wall, and an additional wall is contained in the volume of the working chamber, both walls being made in vertical, limit the volume of the chamber, provide the installation level of the liquid and form a central liquid bath in which the discs are immersed, and at the base of the working chamber of heat and mass transfer, in the horizontal plane along the central axis of the bottom of the liquid bath there is a central triangular rib parallel to the horizontal axis shaft, the height of which is lower than the height of vertically mounted dividing walls and forms the depth of the liquid circuit in the immersion zone of the disks, while at otivopolozhnyh end surfaces of the liquid bath set inlet pressure port and outlet port at a predetermined height in accordance with the setup level of the filling liquid, which is circulated through the working fluid [see. Patent RU 2158393, F24F 3/14, B01D 3/30, 1999].

The disadvantage of the invention is the low efficiency of heat and mass transfer, as well as the possibility of drip entrainment of the liquid.

A device for contacting gas and liquid, comprising a housing with channels for introducing and discharging liquid and gas, a drum with a perforated side wall on which are mounted radial blades mounted for rotation on a hollow drive shaft with an opening communicating the cavity of the shaft with the drum cavity, and a porous drum made with grooves for the entry of radial blades and mounted in the cavity of the perforated drum coaxially with it [see Patent RU 2101642, F28C 3/06, F28F 5/02, 1995].

The disadvantage of this contact device is the low efficiency of heat and mass transfer processes.

A contact device is known for separating the components of a mixture in a distillation unit containing a cylindrical body with a horizontal axis, on which a rotary shaft with a nozzle fixed to it with a developed surface in the form of thin disks is placed [see Patent RU 2259859, B01D 3/28, B01D 3/30, 2003]. The lower half of the housing is equipped with a receiving and overflow pocket with nozzles for supplying and discharging liquid, and the upper half of the housing is equipped with nozzles for supplying and discharging steam. The horizontal size of the pockets and pipes for supplying and discharging steam is equal to the length of the generatrix of the device.

The disadvantage of this device is the relatively small specific surface area of the contact between vapor and liquid, therefore, to achieve a given degree of separation, it is necessary to increase the number of disks, which leads to an increase in the dimensions and metal consumption of the structure. In addition, with an increase in the productivity of the device in pairs, there is a breakdown of the liquid particles from the surface of the film formed on both sides of the upper half of each disk, and droplet entrainment of the liquid by the steam flow, which negatively affects the separation efficiency.

The closest in technical essence and the achieved result is a device for thermal and phase oil regeneration, comprising a housing with channels for supplying cooling air and oil aerosol and removal of oil and air, a rotating drum with perforation on the side wall and radial blades located in the housing on the hollow shaft, located on the inner surface along the entire length of the drum [see A.S. USSR No. 861685, F02C 7/06, F28D 11/02, 1979].

The disadvantage of this device is the low efficiency of heat and mass transfer processes due to drip entrainment of the liquid by the gas stream due to the perforation on the side wall of the drum.

The problem to which the claimed invention is directed, is to increase the efficiency of heat and mass transfer processes in a gas-liquid system by reducing drip entrainment of a liquid.

The problem is solved by a heat and mass transfer apparatus, comprising a housing with nozzles for supplying and discharging liquid and gas, a rotating drum located in the housing on the shaft with radial blades located on the inner surface along the entire length of the drum. The drum has a continuous side wall and is equipped with end caps, in which radial holes are made around the shaft for the passage of gas and liquid. Radial blades are made of sheet material and are bent into two different in width parts of the sheet, and the holes in the end caps of the drum are made so that they do not overlap the end part of the blades.

The technical result of the invention is to reduce droplet entrainment of a liquid and, as a result, increase the efficiency of heat and mass transfer processes in a gas-liquid system.

The invention is illustrated by the following drawings:

- figure 1 shows the proposed heat and mass transfer apparatus - longitudinal section;

- figure 2 is a section aa in figure 1;

- figure 3 is a section bB in figure 1;

- figure 4 is a view of the end cover of the cylindrical drum.

The heat and mass transfer apparatus includes a housing 1 with a shaft 2 located on its horizontal axis, on which a cylindrical drum 3 with end caps 4 is fixed (Fig. 1). In the end caps 4 are made equally spaced radial holes 5, intended for the passage of the contacting phases. On the inner surface of the drum 3, radial blades 6 are uniformly mounted, the length of which is equal to the length of the cylinder generatrix, designed to intensify the processes of heat and mass transfer. Under the horizontal diametrical plane of the housing 1 there are pipes for the supply 7 and drain 8 of the liquid (figure 2), and above the horizontal diametrical plane - pipes for the supply 9 and exhaust 10 of gas (figure 3). Radial blades 6 made of sheet material are bent into two different in width parts of the sheet. The radial holes 5 are made so that they do not overlap the end part of the radial blades 6 (figure 4).

The proposed heat and mass transfer apparatus operates as follows.

The liquid through the pipe 7 fills the lower part of the housing 1 and through the radial holes 5 located in the end caps 4, enters the inner cavity of the drum 3 so that it is half immersed in the liquid, through the pipe 8 the liquid exits the housing 1. Gas through the pipe 9 fills the upper part of the housing 1 and through the radial holes 5 enters the drum 3, through the nozzle 10 the gas exits the housing 1. To ensure maximum throughput of the liquid and gas, the radial holes 5 are in the form of trapezes, tapering to alu. During operation of the apparatus during rotation of the drum 3, the radial blades 6 capture liquid or gas. To exclude the release of trapped liquid or gas through the end caps 4, the radial holes 5 in the end caps 4 of the drum 3 do not overlap the end part of the radial blades 6.

When the drum 3 rotates, the gas inside the blades 6 is immersed in the liquid layer, where the gas is partially compressed and the displaced volume of gas is bubbled through the liquid layer. When the gas volume becomes equal to zero, the blades 6 capture the liquid, which with further rotation of the drum 3 flows in the form of a film onto the surface of the liquid flow. Analyzing the working process of the prototype and the proposed heat and mass transfer apparatus, it can be argued that the proposed apparatus allows heat and mass transfer processes with heat and mass transfer coefficients at least at the same level as the prototype. To ensure maximum process efficiency, radial blades are performed with a generatrix angle of 30-55 °.

Due to the fact that the contact between the gas and the liquid occurs in the inner cavity of the drum, the side wall of which, in contrast to the prototype, is solid, there is a significant reduction in droplet entrainment of the liquid with the gas stream. With an increase in gas or liquid productivity, the proposed heat and mass transfer apparatus will experience a significantly lower drop of liquid ablation compared to the prototype, that is, the proposed apparatus will reliably operate in a wider range of changes in liquid and gas flow rates. In addition, the absence of small holes on the surface of the drum eliminates their clogging, therefore, the proposed device, unlike the prototype, will ensure efficient operation in the presence of contaminants in gas or liquid flows.

Thus, the reduction of droplet entrainment of a liquid with a sufficiently high intensity of interaction between gas and liquid in the proposed heat and mass transfer apparatus leads to an increase in the efficiency of heat and mass transfer processes in the gas-liquid system.

Claims (3)

1. Heat and mass transfer apparatus, comprising a housing with nozzles for supplying and discharging liquid and gas, located in the housing on the shaft of a rotating drum with radial blades located on the inner surface along the entire length of the drum, characterized in that the drum having a solid side wall is provided with end covers in which radial openings are made around the shaft for the passage of gas and liquid, the radial blades are made of sheet material and are bent into two different parts of the sheet in width, and the holes in the end caps of the drum are made so that they do not overlap the end part of the blades. 2. Heat and mass transfer apparatus according to claim 1, characterized in that the forming angle of the radial blades is 30-55 °. 3. The heat and mass transfer apparatus according to claim 1 or 2, characterized in that the holes in the end caps are in the form of trapezoids, tapering to the shaft.

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