SU1342522A1 - Regular packing - Google Patents

Abstract

The invention relates to the chemical, petrochemical, gas, food, and other industries. The purpose of the invention is to increase the efficiency of the nozzle and reduce the hydraulic resistance. The essence of the invention is that in a regular nozzle for heat and mass transfer apparatus containing vertically arranged sheets 1, forming channels, the distance between the sheets S; increases from the center to the periphery, and all the channels, except for the two central ones, are equipped with additional plates 2, and the width of the plates Lb - increases from the central channels to the peripheral ones. Additional plates are installed either parallel to vertically arranged sheets, or made in the form of longitudinal ribbing of vertically arranged sheets, the number of edges increasing from the central channels to the peripheral ones, and their total height for each i-ro channel is equal to the width of the additional plate bn; . The distance between the sheets is calculated from f-le: S; irH / 4Z e, and the width of the plates bnj, where R is the radius of the apparatus; Z is the number of channels in the semicircle; X is the distance from the axis of the apparatus to the center of the i-ro channel. 3 з.п, ф-л, 3 Il. & (L with 4 N5 SL GO yu

Description

113

The invention relates to the chemical industry and other industries and can be used for conducting mass transfer processes in gas (vapor) - liquid systems.

The purpose of the invention is to increase the efficiency of the nozzle by increasing the yield surface of the nozzle and reducing the hydraulic resistance by eliminating local resistances associated with the hydraulic impact of the gas.

FIG. 1 shows a regular attachment with additional plates installed in parallel, top view; in fig. 2 - a regular attachment with / additional plates in the form of longitudinal ribs, top view; in fig. 3 — nozzle with longitudinal ribbing and irregular distance, grease, ribs, view, from above.

The reg, bay nozzle (fig. 1-3) contains vertically arranged sheets 1, the distance between which increases from the center to the periphery, as well. all the channels, except for the two central ones, are provided with additional plates 2. Additional plates (Fig. 1 are installed parallel to vertically spaced sheets, between which o; increase from the center to the periphery by the formula

 4Z®

or

  - 4Z

and the nozzle is provided with additional plates installed in the nozzle channels, the total width of which increases from the central to the peripheral channels in accordance with the equation:

g b,

um

R

(2)

where R is the radius of the apparatus;

Z is the number of channels in the semicircle. Additional plates 2 (Fig. 2) are made in the form of longitudinal ribbing of vertically arranged sheets 1, with the number of plates increasing from the central channels to the peripheral ones, and their total width for each i-ro. The channel is made equal to the width of the additional plate defined by equation (2).

The distances between the plates 2 (Fig. 3) in each channel increase from the longitudinal axis of the vertically arranged sheets 1 to their periphery.

The nozzle works as follows.

Liquid with a distributor and gas is fed from above. When they interact, they obtain gas-liquid

15

 ) 20

25

thirty

35

, enters the channels formed by vertically spaced sheets 1 (Fig. 1-3). Gas discards particles

liquids on sheets 1 and additional plates 2 due to the fact that its speed is many times greater than the speed of the liquid (the proposed nozzle stably operates at a gas velocity of up to 50-60 m / s, while the nozzle is known in backflow mode where the gas velocity is in the order of 3.5-4 m / s). The gas moving through the nozzle channels intensively interacts with a film of liquid flowing on both sides of the vertically arranged sheets 1 and additional plates 2.

In the film apparatus, there are two main hydrodynamic regimes: the mode of weak and strong hydrodynamic interaction of the phases, in the first of them in the smaller, and in the second in the greater degree along the surface of the liquid film.

Additional plates 2 (Fig. 1) are installed in parallel to vertically spaced-off sheets 1. Such constructions allow to increase the efficiency of the nozzle by ensuring uniform distribution of the phases, over the cross section of the apparatus in a plane, the perpendicular surface of the vertically arranged sheets and increasing the specific surface of the nozzle, to reduce the hydraulic resistance due to the exclusion of local resistances associated with repeated abrupt changes in direction, constriction and expansion of the gas flow, with its hydraulic impact on the inclined petals. The specific surface area of the proposed nozzle is larger than that of the externally mounted nozzles due to the fact that additional plates are installed and the distance between the sheets increases from the center to the periphery, i.e. with the same number of sheets large

45

50

55

part of them is located in the central part of the apparatus.

Additional plates 2 (Fig. 2 are made in the form of a longitudinal ribbing of vertically arranged sheets 1. This design, while retaining the advantages of the nozzle (Fig. 1), increases the rigidity of the nozzle sheets and the durability of the device.

The distance between the plates 2 (Fig. 3) in each canape is increased from the longitudinal axis of the vertically arranged sheets 1 to their periphery in order to improve the uniformity of phase distribution over the cross section of the apparatus and in a plane parallel to the surface of the vertically arranged sheets.

For a plane-parallel packing, friction resistance is decisive, which is determined by the well-known Darcy-Weisbach formula;

LR.

1 Рп «2

(3)

P da 2

where L is the coefficient of friction resistance;

1 - nozzle length; dg - equivalent nozzle diameter;

p2 is the gas density; О - relative gas velocity The hydraulic resistance of the nozzle should be equal to the hydraulic resistance of each channel. Based on this, you can write

LR

tr,

 ;

or

-Pj- i a - i-

 d.

2

For the quadratic region of the ribbon mode, the coefficient is constant, then, by equation (4),

; 0,5 d

d

and con

From expression (5) it follows that Q, W;

or TV 9 i

Thus, the condition for the equality of speeds 1 aza in the channels is the equality of equivalent diameters of the channels

31

 d

ji

(6)

In a similar way, it can be proved that when equality (6) is fulfilled in the turbulent mode described by the Blasius equation, the gas velocities in all channels are also the same.

The equivalent diameter of the i-ro channel is determined by the formula

(7)

 4F;

d ;; - ---,

moistened perimeter of i-ro channel;

cross sectional area

1st channel.

Optionally, condition (6) can be as follows:

25

F. F; ; P, P; .

(8) (9)

,

35

;

50

55

Thus, removing conditions (6), (8) and (9), achieve equality

30 velocities over the cross section of the apparatus, and, consequently, a uniform phase distribution.

A program has been developed for calculating the on-computer of a cylindrical apparatus with the proposed nozzle, based on the conditions (8) and (9). For work, you need to enter only two parameters: the radius of the apparatus R and the number of channels Z in the semicircle.

4Q The results of the calculation show that in order to fulfill the condition (8) in the cylindrical apparatus, the distance between the sheets S is necessary; increase from center to periphery. To perform

- conditions (9) all channels, except two central ones, must be provided with additional plates, and the width of the plates should be increased from the central channels to the peripheral ones.

After analyzing the results of calculating a computer for different combinations of R and Z, one obtains empirical formulas for determining the distance between the vertically spaced sheets S; (1) and additional plate widths

bnl (2). .

Claims (4)

Invention Formula 1. A regulative nozzle for heat and mass transfer apparatus containing 51 vertically arranged sheets forming channels, characterized in that, in order to increase its efficiency by increasing the specific surface of the nozzle and reducing hydraulic resistance by eliminating local resistances, gas shocks, the distance between the sheets increases from the center to the periphery according to formula 8.L. 4Z and the nozzle is equipped with additional plates installed in its channels, the total width of which is b "; increases from the central to the peripheral channels in accordance with the equation b R Where R z hradius apparatus; the number of channels in the semicircle; the distance from the axis of the apparatus to the center of the i-ro channel. 2. The nozzle of claim 1, wherein the additional plates are installed parallel to the vertically spaced sheets. 3. The attachment according to claim 1, wherein the additional plates are formed in the form of a longitudinal ribbing of vertically arranged sheets. 4. The nozzle of claim 3, wherein the distance between the additional plates in each channel increases from the longitudinal axis of the vertically arranged sheets to their periphery. Figg Compiled by A. Sondor. Editor N. RoguLich Tehred I.Popovich Proofreader. Obruchar 4542/5 Circulation 656 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 (Riga.Z