SU1729565A1 - Reactor - Google Patents

Abstract

The invention relates to equipment for processes of contacting a liquid or gas with a fixed bed of a granular layer of granular material, can be used in processes of contacting a liquid or gas in a fixed catalyst bed and allows to simplify the design. The invention relates to equipment for processes of contact of a liquid or gas with a fixed bed of granular material, in particular, to radial-type reactors, and can be used, for example, in the chemical, petroleum refining and petrochemical th industry. Known reactor, including a cylindrical body and coaxially installed in it an annular basket with manual transmission and improve the conditions of safety. The reactor, which includes a cylindrical body and a perforated annular basket with a coaxially mounted in it, with a catalyst, the radius of the internal cavity of which is determined from the relation: J. and O2L / O2, gЈ, l / j. jtLR l) + e2. +, 2l 1LUSK +) (Eff + & n LR2i + cnRi (Uel + n LRtz) - | SL R2i) x (Ser +): 0.05, where Ri is the radius of the internal cavity of the ring basket; L is the height of the catalyst bed; VM is the volume of the catalyst bed; ЈSl 3.5 f (1 - e) / e d3 is the hydraulic resistance coefficient of the catalyst bed; Ј is the porosity of the catalyst bed; d3 is the average equivalent diameter of the catalyst particle; F is the factor of the shape of the catalyst particles; Јi, 2 p7.1 (1, 2 + V1 -pi.2 / 2) 2 - coefficients of hydraulic resistance of the inner and outer walls of the perforated ring basket; . - the proportion of the free section of the inner and outer walls of the perforated ring basket. 2 Il. CO With a catalyst whose internal cavity forms a distribution channel. Through this channel, the reactants enter the catalyst bed in a direction perpendicular to the axis of the apparatus. The disadvantage of this reactor is that its design does not ensure uniform distribution of the flow of reagents throughout the catalyst, which reduces the efficiency of the process and degrades the quality of the output products. xj you ate about

Description

Closest to the present invention, there is a reactor comprising a cylindrical body and a ring basket mounted coaxially in it with a catalyst, inside of which a central body of rotation is placed. The radius of the body of rotation is determined by the relation:

(1 + vTq) - 1.5 0. dy 4r0uV) 1 -Y v

(one)

1.5royt / 3

A2lr0yV

uniform distribution of the flow of reagents over the catalyst bed with a relative pressure drop in the distribution channel formed by the internal

the cavity of the ring basket, in the range of relative pressure drop from 1 to 2.5, which covers almost all real radial fixed bed reactor. This is the ratio

L 1 Apk (3)

(G2 G2) (1 - Y) 4 (G2 - G, jtf - rtyl - Y) 2

where 1 -z- is relative area

Go

cross section of the distribution channel with the central body of optimal shape.

To achieve this goal, it is proposed in the reactor, which includes a cylindrical body and a perforated annular basket with a catalyst coaxially mounted therein, to determine the radius of the inner cavity of the annular basket from the ratio

2t. (V.a + j4Rt)

SOS (2)

tfKlO c. + Li) -f + Ј „H | (ui-nal) - &. R VnL (Vc, + rt.M) J

where Ri is the radius of the internal cavity of the ring basket;

L is the height of the catalyst bed;

VM is the volume of the catalyst bed;

Јsl --D - coefficient guideЈ3d3

equal resistance of the catalyst bed;

e-porosity of the catalyst bed;

da is the average equivalent particle diameter of the catalyst;

F is the factor of the shape of the catalyst particles

iu Vhb () are the hydraulic resistance coefficients of the inner and outer walls of the perforated ring basket;

# 1.2 - lobes of the free section of the inner and outer walls of the perforated ring basket.

As a result of the analysis of the experimentally validated mathematical model of the aerodynamics of a radial reactor, a relation

g is the current radius of the central body; r0 is the radius of the inlet section of the distribution channel;

y x / l is relative coordinate; x is the distance from the top to an arbitrary section of the central body; I - height of the central body; AI is the hydraulic resistance coefficient of the distribution channel;

P is the inner radius of the annular channel;

ha is the outer radius of the annular channel; Aa is the hydraulic resistance coefficient of the annular channel.

This reactor, due to the use of a rotation body with a specially calculated radius in the distribution channel, provides a more even distribution of the reagent flow throughout the catalyst. However, the shaped body of rotation has a complex shape and, therefore, is laborious to manufacture. The presence of a body of rotation in the distribution channel complicates the design of the apparatus. In addition, at high temperatures of the process, the metal structure of the body of rotation may break due to stresses arising in it, explosive components of the reaction mixture may accumulate in the hollow body, which will cause an explosion when the apparatus is purged with air.

The purpose of the invention is to simplify the design of the reactor and to improve safety conditions while ensuring an even distribution of the flow of reagents over the catalyst bed.

5 max max min - the degree of uneven Umax

the flow of reagents;

VMSKC, VMHH - the maximum and minimum value of the radial component of the reagent flow rate at the entrance to the catalyst bed;

 Uex / 2 - pressure drop in the distribution channel;

p is the density of the mixture of reagents under operating conditions;

UBX Q / (n R2i) is the flow rate at the entrance to the distribution channel;

Q is the flow rate of the mixture of reagents under operating conditions;

Ar

4l2.2

+ | + IJ ij

the pressure drop over the catalyst bed and the walls of the perforated ring basket, which constitutes the main resistance share of the entire reactor;

On m / sl / (L) + F is the radius of the outer wall of the annular basket.

To achieve a uniform distribution of the flow of reagents, it is sufficient to have 5V 0.05. Then, by substituting the expressions for DRK and AR into expression (3), we obtain relation (2) for calculating the radius of the inner cavity of the annular basket, which achieves a uniform distribution of the flow of reagents over the catalyst bed.

The structural scheme of the proposed reactor is presented in figure 1.

The reactor contains a cylindrical body 1, a coaxial perforated ring basket 2 installed therein with a catalyst 3, nozzles for input 4 and output 5 for the flow of reagents. The inner cavity of the annular basket forms a distribution channel 6.

The reactor operates as follows.

The flow of reagents through the pipe 4 is fed into the distribution channel 6, from where it enters the catalyst bed 3. Pass through the catalyst bed 3 and the outer wall of the perforated ring basket 2, the flow of reagents through the annular space formed by the housing 1 and the outer wall of the ring basket 2 - collecting channel - enters pipe 5 and is withdrawn from the reactor.

PRI me R. On a cold stand, an experiment was carried out with an apparatus in whose case a perforated ring basket is coaxially installed. The basket is filled with limestone. For this unit: Men 0.075 m; ЈSL 19800 (determined experimentally); , 2 0 for a mesh with a cell of 0.003x0.003 m, of which the basket is made, then Јi, 2 0; L 0.8 m. The radius of the distribution channel calculated by the formula (2) is: RI

ten

15

20 25

thirty

35

40 45 50 55

0.065 m. The outer perforated shell radius for US $ 0.075 m is 0.185 m.

Under the normal conditions, air with a flow rate of 0.14 m3 / s was supplied to the internal cavity of the annular basket — the distribution channel of the apparatus. The air velocities at the exit from the layer of granular material were measured with a thermal anemometer with a special cylindrical nozzle at 24 points of the cross section of the layer at 12 Rus.

Figure 2 presents the profile of the relative velocity of the gas at the outlet of the layer of granular material, measured experimentally and calculated according to the mathematical model. As can be seen from figure 2, the profile is almost uniform.

The degree of uneven distribution of the flow, the gas calculated for this apparatus according to the formula (3), is 5V 0.017.

Thus, the use of the proposed reactor ensures uniform distribution of the flow of reagents in the catalyst bed. In this case, in comparison with the prototype, the design of the reactor is simplified, and safety conditions deteriorate.

Claims (1)

Invention Formula A reactor containing a cylindrical body and a perforated annular basket with a catalyst coaxially mounted therein with a catalyst, characterized in that, in order to simplify the design and improve safety conditions, the radius RI of the internal cavity of the annular basket is determined from the ratio g |. (AT + CHY) Rte (Vc. + ШЙ) + fcAltf + {uRi (Vu + utf} -6 R VnL (Yc. + Я-М)) where L is the height of the catalyst bed; Wye - catalyst volume, Јsl - the coefficient of hydraulicЈ3d3 equal resistance of the catalyst; e-porosity of the catalyst bed; ds is the average equivalent particle diameter of the catalyst; F - factor of the form of the catalyst particle; , 2 (i-Vu + 1F iEr) 2 hydraulic resistance coefficients of the inner and outer walls of the perforated ring basket; .2 is the fraction of the free section of the inner and outer walls of the perforated annular basket. I FIG. one