RU2237508C1 - Mass-exchange contact device - Google Patents

Abstract

FIELD: food-processing, chemical, petro-chemical, oil refining and other industries.

SUBSTANCE: proposed device includes plate with contact member, shell, movable two-way valve and hoisting and lowering limiters. Shell has holes over its perimeter and movable two-way valve consists of two solid plates mounted one above other; device is provided with additional surface of plate. Contact member is used as hoisting limiter and edge of shell is used as lowering limiter. Lower edges of shell holes are made in form of inner cap with bent plates of bubbling unit; height of vertical holes over perimeter of shell is equal to height of two-way valve; with two-way valve in extreme positions, each its plate divides free passage of vertical holes of shell into equal parts. Proposed construction provides for considerable increase of free passage for gas (vapor) and liquid, thus enhancing mass exchange. Contact device makes it possible to perform mass exchange in gas (vapor)-liquid system in cyclic mode at change of liquid delay on all plates in height of column. Each contact member operates independently, thus excluding effect of pressure pulse delay at moment of delivery of vapor to column. At moment of opening of transient volume, additional contact zone is formed. Proposed contact member excludes mixing of liquid from adjacent stages.

EFFECT: enhanced efficiency of mass exchange.

6 cl, 4 dwg

Description

The invention relates to mass transfer contact devices, and in particular to devices intended for carrying out mass transfer processes in a gas (steam) - liquid system under cyclic conditions (with a separated phase movement along the column), and can be used in food, chemical, petrochemical, oil refining and other industries.

Known mass transfer contact device, which contains a plate plate with contact elements. Annular holes with jumpers are made in the plate cloth along the periphery of the contact element, and a central hole is made under the contact element, along the axis of which there is a pipe and a shell under the plate plate. The shell is equipped with a bi-directional valve located in the middle with the possibility of movement. The valve is made in the form of plates mounted one above the other and connected by distance posts with central holes. The upper hole serves for the passage of the nozzle, and under the lower hole on the rod between the limiters of raising and lowering a break valve is installed.

The disadvantage of this device is the multielement (two-element) of the movable parts of the structure, the restriction of the free passage of the pipe for gas (steam) and the free passage of the annular holes for the liquid. These shortcomings increase the hydraulic resistance of the plate during the passage of gas (steam) and increase the time the liquid flows from the plate to the plate.

The basis of the invention is the task of improving the known device, namely, ensuring optimal operating conditions of the apparatus in a cyclic mode of mass transfer processes, reducing the influence of the delay of the pressure pulse of the gas (steam) molasses along the height of the column due to the autonomous operation of each contact device with a separate phase movement and thereby increase in productivity and reliability of the structure.

The problem is solved in that the mass transfer contact device comprises a plate cloth with a contact element, a shell, a movable double-sided valve, limiters for raising and lowering, in accordance with the invention, the circumference of the shell has holes, the movable double-sided valve is made in the form of solid plates mounted one above the other, moreover, the device is equipped with an additional plate plate. The limiting element for raising the double-sided valve is the contact element, and lowering is the lower edge of the shell. The lower edges of the shell holes are made at the level of the additional (lower) plate plate. In addition, the contact element is made in the form of an inner cap with the bubbler assembly bent along the tangent plates, the height of the vertical holes along the circumference of the shell is equal to the height of the two-sided valve, and in the extreme positions of the two-sided valve one of the valve plates divides the free passage of the vertical holes of the shell into equal sectors.

The causal relationship between the proposed features and the technical result is as follows.

1. The holes for the passage of liquid and gas (steam) are made along the perimeter of the shell, which makes it possible to significantly increase (up to 50% or more) the “free passage” for gas (steam) and liquid, thereby increasing the mass transfer rate and, accordingly, the productivity of the device.

2. To close and open the transitional volume, one two-way valve is used, and not two valves, as in the closest analogue. This significantly increases the reliability of the contact device and simplifies its design.

3. The continuous upper and lower plates of the two-way valve expand the gas load range of the column (steam) by reducing the working pressure drop across the plate.

4. The flow of liquid from the upper plate of the plate into the transitional volume is much faster, since the liquid passes without resistance through a continuous hole in the inner cap.

5. The implementation of the contact element in the form of an inner cap with the bubbler unit bent along the tangent plates makes it possible to impart a rotational movement to the liquid during sparging and to use additional turbulization when exiting the contact element due to the oncoming flow effect. In this case, the surface of mass transfer increases significantly and the efficiency of the device increases.

Figure 1 shows the device in a position that corresponds to the initial moment of supply of gas (steam).

Figure 2 - in a position that corresponds to a change in the application of lifting force from the lower to the upper plate of the two-way valve.

Figure 3 - in a position that meets all subsequent moments of the gas (steam).

Figure 4 is a top view.

The contact device consists of a plate cloth 1, on which a contact element 2 is fixed with the bubbler assembly 3 bent along the tangent plates, a shell 4 with holes 10 and 11 under the plate cloth 1, an additional (lower) plate cloth 5, a two-way valve that moves in the middle shell 4 and consists of the upper 6 and lower 7 plates connected by a distance stand 8, the bent lower edge of the shell 4 acts as a limiter lowering.

The contact device operates as follows. The gas (vapor) phase during the vapor period (steam rises up the column, there is no flow of liquid from the plate to the plate) lifts the valve to a fixed upper position so that the upper plate 6 of the two-way valve closes the hole of the contact element. Steam passing through the bubbler assembly 3 of the contact element 2 interacts with the liquid layer that is on the plate (the liquid arrived earlier from the plate located above), sparges through the layer.

After the end of the steam period, the flow of gas (steam) ends and the two-way valve, under the influence of its gravity and the weight of the liquid, falls down until its movement stops the lowering limiter 9 of the shell 4.

Since the liquid and the valve fall under their own weight, the opening 10 of the shell 4 will be closed by the bottom plate 7 before the liquid reaches the plate 7. The liquid from the bubble zone on the plate 1 passes through the holes 11 of the shell 4, enters the volume limited by the shell 4, an additional lower plate blade 5 and a two-way valve (transitional volume).

The delay time for the supply of steam (gas) will be determined by the time the liquid flows from the plate plate 1 into the above volume and will be tenths of a second.

At the initial moment of gas (steam) supply, the lifting force due to the pressure drop will act on the lower plate of the two-way valve. Under the action of this force, a two-way valve will move upwards, followed by a liquid that is in the transitional volume.

At the time when the plates of the double-sided valve align with the holes of the shell 4, the application of lifting force passes from the lower 7 to the upper 6 plate of the double-sided valve.

Gas (steam) passes into the holes of the shell 4, sparging through the liquid. As the hole increases, the speed of the vapor that passes through the hole will fall and conditions will be created for the liquid to transfer to the lower plate.

The two-way valve continues to move up to a fixed upper position. The weight of the two-way valve and the liquid column above them must be less than the force of the differential pressure that acts on the upper plate.

The time the liquid flows from plate to plate is called the liquid period. Thus, the cycle time, which consists of the vapor and liquid periods, ends. Subsequent cycles are similar.

The proposed contact device allows for the mass transfer process in a gas (steam) - liquid system in a cyclic mode with a single change in the liquid delay simultaneously on all plates along the column height. In addition, each contact device operates autonomously, which eliminates the effect of delayed steam flow pulses during the period of steam supply to the column.

At the moment of opening of the transitional volume, an additional contact zone is created.

Using the proposed contact device eliminates fluid mixing at adjacent contact steps and allows to increase the mass transfer efficiency by two to three times in comparison with the stationary process.

Claims (6)

1. Mass transfer contact device, which comprises a plate cloth (1) with a contact element (2), a shell (4), a movable two-way valve, limiters for raising (2) and lowering (9), characterized in that it contains an additional plate cloth (5 ), the shell (4) along the perimeter has openings (11), and the movable two-way valve is made in the form of solid plates mounted one above the other, connected by a distance stand (8). 2. The device according to claim 1, characterized in that the lower edges of the holes (11) of the shell (4) are made at the level of the additional plate cloth (5). 3. The device according to claims 1 and 2, characterized in that the limiter for raising the two-way valve is the contact element (2), and lowering is the lower edge (9) of the shell (4). 4. The device according to any one of the preceding paragraphs, characterized in that the height of the holes (11) of the shell (4) is equal to the height of the two-way valve. 5. The device according to any one of the preceding paragraphs, characterized in that in the extreme positions of the two-way valve, one of its plates provides a division of the free passage of the holes (11) of the shell (4) into equal sectors. 6. The device according to any one of the preceding paragraphs, characterized in that the contact element (2) is made in the form of an inner cap with a bubbler assembly (3) bent along the tangent plates.

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