RU2049542C1 - Packed heat-exchange and mass-transfer cross-flow column - Google Patents

Abstract

FIELD: petroleum refining industry. SUBSTANCE: in the known packed heat-exchange and mass- transfer cross-flow column, used a housing accommodating the packing, separated into sections by horizontal partitions with holes for passage of vapors (gas) and liquid, according to the invention, the horizontal section of the column at each step of contact is separated into sections consisting of a zone of vapors (gases) inlet, zone of vapor (gas) and liquid contact, and zone of transfer of liquid to the below-lying step, and vapor (gas) to the above-lying step, forming within the column a helical motion of liquid and vapor (gas) about its vertical axis; the degree of sectionalizing liquids and vapor (gas) flows is the same and equal the quantity of sections at the step of contact. EFFECT: enhanced efficiency of heat exchange and mass transfer due to the increase of the number of contact steps at helical motion of vapor and liquid flows. 3 dwg

Description

 The invention relates to the refining, petrochemical and gas industries, specifically to apparatus for conducting heat and mass transfer processes in gas (steam) liquid systems.

Known nozzle column comprising a cylindrical vertical housing with vertically arranged nozzle sections made in the form of a hollow polyhedron. The column is equipped with blind partitions connected in its center [1]
A heat and mass transfer column is also known, comprising a housing in which a nozzle is placed divided into sections by horizontal partitions with openings for the passage of steam (gas) and liquid, in which, in order to increase the efficiency of mass transfer, the path of steam (gas) is increased within one contact stage. To achieve this goal, the column is equipped with a vertical blind wall installed at a distance from the column body, providing rotational-vibrational movement of the steam flow in the volume of the column [2]
The aim of the invention is to increase the efficiency of heat and mass transfer by increasing the number of contact steps during the helical movement of steam and liquid flows.

 This goal is achieved by the fact that in the known packed cross-flow column, comprising a housing in which the nozzle is placed, divided into sections by horizontal partitions with holes for the passage of steam (gas) and liquid, according to the invention, the horizontal section of the column at each contact stage is divided into sections, consisting from the zone of entry of steam (gas), the zone of contact of steam (gas) and liquid, and the zone of flow of liquid to the downstream and steam (gas) to the upstream stage, forming a screw in the column the flow of liquid and vapor (gas) around its vertical axis, and the degree of sectioning of the liquid and vapor (gas) flows is the same and equal to the number of sections at the contact stage.

·

·

, где

= b эквивалентная толщина насадочного блока, мм;
G_вх объемный расход потока пара (газа), м³/с;
L_вх объемный расход потока жидкости, м³/с;
П плотность жидкостного орошения, м³/(м² ˙с);
ω_г линейная скорость потока пара (газа), м/с.It is known that the geometric height of the nozzle layer for cross-precise contact above the acting phases in the vapor-liquid system is determined as follows [3]
H

·

·

where

= b equivalent thickness of the nozzle block, mm;
G _Vh volumetric flow rate of the vapor stream (gas), m ³ / s;
L _inlet volumetric flow rate of the fluid flow, m ³ / s;
P the density of liquid irrigation, m ³ / (m ² ˙ s);
ω _g linear velocity of the vapor (gas) flow, m / s.

F_г площадь под проход газа, м²;

F_ж площадь под проход жидкости, м²;

l длина слоя насадки, м.Wherein

F _g area under the gas passage, m ² ;

F _{W the} area under the passage of fluid, m ² ;

l the length of the nozzle layer, m

.From here H

.

With the same length of the nozzle layer and the steam flow velocity ω _g , determined from the dynamics of the contacting vapor and liquid flows, the height of the nozzle layer depends on the volumetric flow rate of the steam stream. It follows that a decrease in volumetric flow rate reduces the height of the nozzle layer.

 An increase in the number of steam (gas) inlets by a factor of N reduces the height of the nozzle layer by a factor of N (Fig. 1) and the number of contacts at one stage by a factor of N, while the number of contacts increases by a factor of N at the same height as with the single-shot version (figure 2), i.e., the number of contacts does not change, but the concentration of the liquid entering each contact stage at the same column height changes.

 In FIG. 1 shows a scan along the perimeter of a heat and mass transfer crossflow column, divided into 3 sections; in FIG. 2 scan along the perimeter of the heat and mass transfer cross-flow column un-sectioned) with one steam inlet); in FIG. 3 heat and mass transfer crossflow column with the number of sections equal to two in a perspective view.

 The proposed column consists of a cylindrical body 1, horizontal partitions 2 with openings 3 for gas passage, which are limited by vertical partitions 4 and drain strips 5, nozzle packages 6 are installed on horizontal partitions, above which a distribution plate 7 is installed, and each overlying package is displaced relative to the underlying in counter-flow of steam (gas) by an angle equal to half the angle of the nozzle pack in vertical projection.

 The column works as follows.

 The flow of steam (gas) comes from the holes 3 (in Fig. 3 N = 2) for the passage of steam 3 in the partitions 2 and is sent to the nozzle packs 6, the steam passes the nozzle packs in a cross current, in contact with the overflowing fluid under the influence of hydrostatic pressure the contact level offset relative to the underlying countercurrent steam by an angle equal to half the angle of the nozzle package in vertical projection.

 The remaining flows of vapor and liquid move in a similar manner, thereby creating a helical N-way in FIG. 3 N = 2 the movement of the flow of steam and liquid, while the flow of steam moves relative to the flow of fluid through a reverse screw.

 The use of a multi-start design of a heat and mass transfer crossflow column with helical movement of steam and liquid flows allows increasing the path of gas (steam) movement and the number of contact steps along the height of the column.

Claims (1)

 NOZZLE HEAT AND MASS EXCHANGE CROSS COLUMN, comprising a housing in which a nozzle is placed, divided into sections by horizontal partitions with holes for the passage of steam (gas) and liquid, characterized in that the horizontal section of the column at each stage is divided into sections consisting of a zone of entry of vapors (gases ), the contact zone of steam (gas) and liquid, and the zone of fluid flow to the downstream and steam (gas) to the upstream stage, forming in the column volume the helical movement of fluid and steam (gas) flows in the circle of its vertical axis, and the degree of sectioning of the fluid and vapor (gas) flows is the same and equal to the number of sections at the contact stage.

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