SU1357029A1 - Method of setting heat-mass exchange processes in gas-liqiud system and apparatus for effecting same - Google Patents

Abstract

The invention relates to the field of chemical technology and is intended for carrying out physicochemical processes in heterogeneous gas-liquid systems. The goal is to increase efficiency by increasing the rate of heat and mass transfer, sID reagent through the pipe 4 is introduced into the case with a hermetically closed lid 2 and removed through pipe 3, 0.75 Q of gas is fed through the valve 15 into the collector, and from it in the system of bubbling tubes 7 and bubbling gas through the layer of liquid continuously. The gas flow rate O, 25 Q is fed through the valve 13, the device 12, which creates a pulsating gas supply with a ratio between the duration of the pulse feed and the delay time of 2-10 s, to the manifold, and from there to the system coaxial to the body of segmented bubble tubes 9. The reacted gas is removed from the apparatus through the nozzle 6. Inside the apparatus, an intense two-circulation flow occurs, 2 s.p., phyla, 4 sludge. SS (L with, sd about Le with

Description

I

The invention relates to the field of chemical technology and is intended for carrying out physicochemical processes in heterogeneous gas-liquid systems.

The aim of the invention is to increase efficiency by increasing the rate of heat and mass transfer processes,

In the method of carrying out heat and mass transfer processes in the system ha-liquid in the apparatus of continuous action, continuous

357029

current lines in the apparatus, top view; FIG. 4 is a graph of the distribution} 1 and the flow rate of the liquid reagent along the radius (curve 1, at 45 hours, approximate curve 2),

The device consists of a housing 1 with a lid 2, the outlet pipes 3 and the supply 4 of liquid reagent are installed in the case, as well as the gas inlet 5, a pipe 6 of the exhaust gas is installed in the joint, a system of 7 parallel bubbling pipes is installed near the bottom of the device

ten

gas sparging into the area of the apparatus, with the support of 8, and the system 9 coaxial to the body

the base surface of which is symmetric with respect to projection to the bottom of the straight line passing through and connecting to the liquid reagent inlet and outlet, and sparging through the layers located between the side wall of the apparatus and the continuous bubbling area, are pulsed, while the ratio between the duration is 1 with a pulse feed and a delay time of 3-55, and the delay time is 2-10 seconds, with 0.75 Q being supplied to the continuous bubbling area, and 0.25 Q to the pulse gas supply area, where Q is the gas flow rate .

In a device comprising a housing with gas inlet and outlet nozzles in a liquid, a bubbling tube system, a device for pulsed gas supply, with the central bubbling tubes arranged perpendicularly and symmetrically to the projection on the bottom of the liquid reagent passing through the inlet and outlet nozzles, ends these bubble tubes are installed on

 R x

radius,

R is the radius of the apparatus, avg is the azimuth angle, and the number of holes per linear meter of pipes is determined by the expression N / N 0.48 + 0.311 - -0, 9931.) Where 1 L / RJ L is the distance from the line of symmetry bubbling tubes up to the orifice, bubbling tubes in the gap between the wall of the body and the central bubbling tubes are made in the form of segments and arranged coaxially with the body and connected by means of manifolds to a device for pulsed gas supply.

Fig „1 shows an apparatus with the image of the flow structure in it, a side section; FIG. 2 is a section A-A in FIG. 1; Fig 3 - distribution

standing from the center of the equal g X (1 -cf + 0,), where g 57029

current lines in the apparatus, top view; FIG. 4 is a graph of the distribution} 1 and the flow rate of the liquid reagent along the radius (curve 1, at 45 hours, approximate curve 2),

The device consists of a housing 1 with a lid 2, the outlet pipes 3 and the supply 4 of liquid reagent are installed in the case, as well as the gas inlet 5, a pipe 6 of the exhaust gas is installed in the joint, a system of 7 parallel bubbling pipes is installed near the bottom of the device

ten

0

five

five

Segmental pipes connected to a manifold 10 connected to a gas pipeline 11, in which a device 12 for pulsed gas supply is installed, the gas pipeline further through a valve 13 is connected to a high-pressure pipeline. A manifold 8 is connected to a high pressure line via conduit 14 and valve 15.

The method is implemented in the apparatus as follows.

Liquid reagent through the pipe 4 is introduced into the housing 1 with the hermetically sealed clamp 2 and output through the pipe 3. Feed 0.75 Q of gas through the valve 15 to the collector 8, and from it to the system 7 bubbling pipes and sparging gas through a layer of fluid continuously. A gas flow rate of 0.25 Q is fed through the valve 13, through the device 12, creating a pulsating gas supply with an ognosis between ;; the duration of the pulse supply and the delay time of 2-10 s into the collector 10, and from there into the system 9 coaxially to the body of segmented bubble tubes. The reacted gas is removed from the apparatus through the nozzle 6. An intensive two-circulation flow occurs inside the apparatus.

Thus, the continuous supply of gas to the region with the base surface, which adjoins the direct, connecting pipe inlet and outlet of the liquid reagent, allows the contact between the main mass of the liquid and gas phases to be effected, since the bulk passes through this region. fluid. An insignificant part of the liquid reagent passes in two gaps e between the area of continuous bubbling and the walls of the apparatus. According to a calculation performed in the model of a viscous fluid for n

0

five

0

current flow, the current function is described by

cf (r, hi) ll. f (u))

I. (C ° 2 H-H o H

R (). Bp; g, r / r; f (q) 0;

Consequently, the gas supply delay time should be equal to the time of passage of the vortices T, defined by the expression

J R / vfv

About f, fr- ,,

where V is the dynamic velocity, V is the average flow velocity, V 2,) is the kinematic viscosity of water.

From the calculation it follows that on the top of the Gravity is constant, CO, the velocity of the gas. Considering that

where r is the radius, (f is the azimuth angle, R is the radius of the apparatus.

expression defined by

g R (1 - tp + 0 ,, there is a sharp decrease in the consumption of liquid reagent, and 75% passes in the central part, and 25% liquid reagent in the two peperifiers, therefore, 0.75 Q should be fed into the central part, and in both peripheral parts - 0.25 Q, where Q is the gas flow rate.

The speed of mass transfer processes depends on the efficiency of mixing. Sunrise, the fluid flows in the central part will be wrapped in the peripheral parts and lowered.

in practice, devices of a radius of 0.5–5 m and liquids of viscosity of 0.005–0.03 cm / s are used; we obtain T 2–10 s.

Due to the fact that in the central zone of bubbling the flow rate of liquid is not the same, the number of openings per linear meter in the bubbling tubes should also be uneven - but also correspond to the flow rate of the liquid reagent. The approximation formula taking into account the flow rate of the liquid reagent is: 25 N / N, (0.48 + 0.311-0.991 f, N „33-57,

20

1 L / R,

downward to form a circulation current, the pulsed gas supply will allow to increase the intensity of this flow, since the melting bubbles 1e prevent the development of the flow, and also create a two circulation in the cross section passing through the axis of the apparatus. A flow of liquid reagent, moving down along the side wall, collides with the outward flow of liquid reagent created by ascending bubbles. As a result of the collision, both streams are turned inside the apparatus, forming a two-circulation flow. The mixing efficiency will be maximum if the flow is rotated in the middle of the apparatus. According to experimental data, the flow velocity in the central part is 1–1.5 m / s, and the flow velocity due to the emerging bubbles in the peripheral part of the apparatus is 0.2–0.3 m / s.

Thus, to create the same circulation flows along the height of the apparatus, it is necessary that the ratio between the pulsed gas supply and the delay time be equal to

thirty

1 L / R,

where L is the distance from the line of symmetry of the central bubbling tubes to the hole.

The maximum number of holes 33-57 is selected from the best bubbling conditions obtained from experimental data, according to which the standing between the holes is 2.5-5 diameters of the holes, and the diameter of the hole is 0.5 cm. There is no coalescence of bubbles at the exit from there is no stagnant tube. Pipes in peripheral areas should be placed in the form of coaxial concentric segments, while stagnant zones can be eliminated.

40

45

50

Formula of invention

one . The method of carrying out heat and mass transfer processes in gas-liquid systems in continuous-flow apparatus by bubbling gas bubbles through a layer of liquid and heat and mass transfer interaction of gas bubbles with a liquid reagent, is characterized in that, in order to increase efficiency by

3-5 At the same time, the created two-circular - 55-degree heat flow rate should not destroy the mass exchange processes, carried out large-scale vortices in the apparatus, "t continuous gas sparging into which promote mixing. the power of the apparatus, the surface of which

 H

3370294

Consequently, the gas supply delay time should be equal to the time of passage of the vortices T, defined by the expression

J R / vfv

 V - dynamic speed kinematic

in practice, devices of a radius of 0.5–5 m and liquids of viscosity of 0.005–0.03 cm / s are used; we obtain T 2–10 s.

Due to the fact that in the central zone of bubbling the flow rate of liquid is not the same, the number of openings per linear meter in the bubbling tubes should also be uneven - but also correspond to the flow rate of the liquid reagent. The approximation formula taking into account the flow rate of the liquid reagent is: N / N, (0.48 + 0.311-0.991 f, N "33-57,

1 L / R,

where L is the distance from the line of symmetry of the central bubbling tubes to the hole.

The maximum number of holes 33-57 is selected from the best bubbling conditions obtained from experimental data, according to which the standing between the holes is 2.5-5 diameters of the holes, and the diameter of the hole is 0.5 cm. There is no coalescence of bubbles at the exit. there is no dead zone. Pipes in peripheral areas should be placed in the form of coaxial concentric segments, while stagnant zones can be eliminated.

Formula of invention

one . The method of carrying out heat and mass transfer processes in gas-liquid systems in continuous-flow apparatus by bubbling gas bubbles through a layer of liquid and heat and mass transfer interaction of gas bubbles with a liquid reagent, is characterized in that, in order to increase efficiency by

is symmetric about the projection to the bottom of the straight line passing through the nozzles of the input and output of the liquid reagent, and is adjacent to it, and the bubbling through the layers between the side wall of the apparatus and the continuous bubbling area is pulsed, while the ratio between the duration the pulse supply and the delay time are 3-5, and the delay time is 2–10 s, the gas flow rate in the continuous bubbling area is 0.75 Q, and in the pulse power supply area - 0.25 Q, where Q is the flow rate gas.

2. A device for conducting heat mass transfer processes in gas-liquid systems comprising a housing with nozzles for supplying and discharging gases and liquids, a system of bubbling pipes installed in the center and on the periphery of the housing, characterized in that

7029

by increasing the rate of heat and mass transfer processes, it is equipped with a device for pulsed gas supply, and the central bubble pipes are located perpendicularly and symmetrically to the projection on the bottom of the straight passing through the pipes for supplying and discharging liquid reagent, while the ends of these pipes set at a distance from the center equal to r R (1 - Cf + 0.41 Rq), where R is the radius of the apparatus, q is the iimuth angle, and the number of openings per 15 meter is determined by the expression N / N3

 (0.48 + 0.311 - 0, where, L is the distance from the line of symmetry of the bubbling tubes to the orifice, and the bubbling tubes in the gap between the wall of the body and the central bubble tubes are made in the form of segments and are aligned with the body and are associated with using collectors with a device for pulsed gas supply.

(puz.Z

Fi.3

I

0.2

OL0.6

Fy

0.8

R

Editor A. Shandor

Compiled by A. Sondor

Tehred M. Didyk Proofreader L. Pilipenko

Order 5917/3 Circulation 657 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

Claims (2)

The claims in continuous 1 . The method of carrying out heat and mass exchange processes in gas-liquid systems by bubbling gas bubbles through a liquid layer and heat and mass transfer interaction of gas bubbles with a liquid reagent, characterized in that, in order to increase efficiency by increasing the rate of heat mass transfer processes, carry out continuous gas bubbling into the area of the apparatus, the surface of which is symmetrical with respect to the projection onto the bottom of a straight line passing through the nozzles of the input and output of the liquid reagent, and prima goes to it, and bubbling through the layers located between the side wall of the apparatus and the area of continuous bubbling is carried out in a pulsed manner, while the ratio between the duration of the pulsed feed and the delay time is 3-5, and the delay time is 2-10 s, moreover, the gas flow rate to the region of continuous bubbling is 0.75 Q, and 0.25 Q to the pulse supply area, where Q is 15 gas flow rate. 2. A device for carrying out heat and mass transfer processes in gas-liquid systems, comprising a housing with nozzles for supplying and discharging gases and 20 liquids, a system of bubblers installed in the center and on the periphery of the housing, characterized in that, in order to 'increase efficiency by increase the speed of heat and mass transfer processes, it is equipped with a device for pulsed gas supply, and the central bubble tubes are perpendicular and symmetrical to the projection onto the bottom of the straight line passing through the supply and outlet pipes ode of the liquid reagent, while the ends of these pipes are installed at a distance from the center equal to r = R (1 - φ + 0.418 sr ^g ), where R is the radius of the apparatus, if is the isometric angle, and the number of holes per meter is determined by the expression N / N _o = '= (0.48 + 0.311 - 0.9931 ^g ) ^g , where 1 = L / R, L is the distance from the symmetry line of the bubble tubes to the hole, and the bubble tubes in the gap between the housing wall and the central bubble tubes the pipes are made in the form of segments and arranged coaxially to the housing and connected by collectors to a device for pulsed gas supply. A-A φυг. g FIG. H