Self circulated cascade gas lift type internal-loop reactor system
Technical field
The present invention relates to a kind of reactor assembly that is applicable to gas, liquid absorption-desorption process or gas, liquid, solid three phase catalytic reaction-catalyst regeneration process, particularly relate to a kind of self circulated cascade gas lift type internal-loop reactor system, belong to field of chemical engineering.
Background technology
Gas, liquid absorption-desorption process, gas, liquid, solid three phase catalytic reaction-catalyst regeneration process are two common and the most basic in chemical industry, petrochemical industry processes.This class process generally all has following characteristics:
1) absorb and the efficient of course of reaction and gas, liquid or gas, liquid, solid three-phase mix and the interphase mass transfer process closely related.2) generally need need two reactors to finish said process at least, reactor is for absorbing or the three phase catalytic reaction device that reacts, and one is desorb or catalyst regeneration reactor.Always the material of some circulates between two reactors, and cyclic process generally need rely on the pump assembly to realize.In a lot of processes, the material circulation has expended lot of energy between two reactors.For example, in typical absorption process, lyosoption is after the absorption tower absorbs gas, be pumped into desorber, lyosoption regeneration in desorber, the lyosoption of regeneration is pumped go back to the absorption tower again, and a large amount of like this lyosoptions is constantly circulation between two towers, and the energy consumption that causes thus becomes one of importance of absorption process energy consumption.
The gas lift type common loop reactor that grows up based on bubbling style reactor, be in bubbling reactor, to add the inner member guide shell, make fluid in reactor, produce circulating around guide shell, thereby realize that the gas, liquid, solid three-phase evenly mixes, and can obtain higher interphase mass transfer coefficient, it is widely used in a lot of gas, liquid, solid phase reactions such as biological fermentation process, sewage disposal process and gas, liquid absorption reaction.
The power that the gas lift type common loop reactor inner fluid flows is the pressure differential that the density contrast of the inside and outside gas of guide shell, liquid mixed phase causes.The mixture density of gas and liquid is lower than the density of the neat liquid under the equal state, thereby the mixed phase fluid column of the gas of equal height and liquid is also littler than the pressure of the fluid column generation of neat liquid.Utilize the motive force of this pressure difference, between two circulation flow reactors, realize self-loopa as the fluid between two reactors circulation, just can reduce significantly this process energy consumption, enhance productivity.
Summary of the invention
The objective of the invention is to: on the basis of gas lift type common loop reactor, propose and set up the tandem reactor system of fluid realization self-loopa between a kind of two common loop reactors series connection, reactor.This reactor assembly utilizes pressure difference that the density contrast of gas, liquid mixed phase and pure liquid phase the causes motive force as the circulation of the fluid between two reactors, need not pumping system, can realize the circulation exchange of fluid between two reactors.The circulation flow reactor gas, liquid, solid three-phase that is adopted evenly mixes, interphase mass transfer coefficient height.Utilize this reactor assembly can efficiently, low energy consumption realize absorption-desorption process, processes such as gas, liquid, solid three phase catalytic reaction-catalyst regeneration process.
The present invention is achieved in that
Reactor assembly is made of two gas lift type common loop reactor A and B.Each reactor includes body of the tower 1, guide shell 2 and gas distributor 3, overflow launder 6.Above reactor, be provided with fluid flow export 4, be provided with fluid inflow entrance 5 at reactor bottom.Fluid flow export 4 is located at the bottom of overflow launder 6, and overflow launder 6 is located at gas-liquid separation zone 7.Connect by pipeline 8 between the flow export of the flow export of reactor A and the inflow entrance of reactor B, reactor B and the inflow entrance of reactor A, constitute the closed circuit between two reactors.
The present invention also adopts following technical scheme:
1) fluid flow export 4 is above guide shell; Fluid inflow entrance 5 is located at the position of reactor bottom, close gas distributor.
2) in the gas-liquid separation zone 7 of overflow launder 6 above the guide shell of reactor, gas, liquid further separate in overflow launder, do not have bubble substantially in the liquid that the flow export 4 of isopipe root flows out.
3) inflow entrance stretches to guide shell inside, and it is highly near the lower edge of guide shell, but is not higher than gas distributor.
4) height of the fluid flow export 4 of a reactor (for example A) is higher than the fluid inflow entrance 5 of another reactor (for example B).
5) height overall of body of the tower A and body of the tower B is 5~15 with the ratio of its internal diameter, and the internal diameter of guide shell 2 and the internal diameter of body of the tower ratio are 0.4~0.9.
6) diameter of reactor A and reactor B can be inequality.Both diameter is than by the time of staying and in reactor B the ratio decision of the time of staying of material in reactor A.
7) guide shell 2 of reactor can be the various forms of guide shells that prior art proposes, and for example can be single-stage, also can be multistage; Can there be 1, also can surpasses 1, in body of the tower 1, place side by side.The form of two reactor inner draft tubes can be identical, also can be different.When guide shell when being a plurality of, the be placed in one lower edge of any 1 guide shell but the position that is not higher than gas distributor of liquid inflow entrance got final product.
8) operating pressure of two reactors is identical.
The characteristics of the self circulated cascade gas lift type internal-loop reactor group that the present invention proposes are:
1) gas is in gas distributor enters guide shell in the reactor, owing to different mixture density difference and the pressure differentials of producing of the distribution of bubble inside and outside guide shell, propelling fluid circulates in reactor, gas dissolution velocity in Airlift circulating reactor is fast, resistance to mass tranfer is little, thereby gas, liquid absorption reaction are gentle, the efficient height of liquid, solid three phase catalytic reaction.
2) from the fluid of overflow launder outflow circulation flow reactor, do not contain gas substantially, and contain a certain amount of gas in the reactor inner fluid, therefore at inflow entrance 5 places, the pressure of fluid is greater than the pressure in the reactor in the pipeline, and liquid is in the guide shell of inflow entrance inflow reactor.Thereby can under the situation of not using pumping system, realize the exchange and the circulation of material in two reactors, saved energy.
3) the present invention is inducted into the negative pressuren zone of guide shell below with the fluid of inflow reactor, promotes the mobile pressure reduction of fluid between two reactors thereby further improve.
4) by adjusting the flow of gas in two reactors, can change the content of gas in two reactors, thus the circulation rate that can regulate fluid between two reactors.
Description of drawings
Fig. 1 is the structural representation of self circulated cascade gas lift type internal-loop reactor group provided by the invention.
Fig. 2 is the A-A cutaway view of reactor A shown in Figure 1, the radially relative position of overflow launder 6, guide shell 2, gas distributor 3, fluid flow export 4 and fluid inflow entrance 5 in the reflection reactor.The situation of reactor B is similar.
Fig. 3 is the self circulated cascade gas lift type internal-loop reactor system that two reactors all have 2 grades of guide shells, and the form of 2 grades of guide shells is inequality in two reactors, among the tower A for segmentation has the inner member of deflection plate, then be perforate on the single-stage guide shell among the tower B.
Fig. 4 is the self circulated cascade gas lift type internal-loop reactor system that one of them reactor A has 3 guide shells.
Fig. 5 is the fluid flow state figure of self circulated cascade gas lift type internal-loop reactor system shown in Figure 1.
Fig. 6 is the flow L of the fluid (fluid of inflow reactor A) that flows out among the autoreactor B
BWith gas volume gas holdup ε among the tower A
ASituation of change.
The specific embodiment
Specify embodiments of the present invention below in conjunction with accompanying drawing.
As Fig. 1 and 2, the present invention is made of two gas lift type common loop reactor A, B.Connect by pipeline 8 between two reactors, include pipe fittings such as valve on the pipeline 8.Each reactor includes body of the tower 1, overflow launder 6, guide shell 2 and gas distributor 3.After gas sprays from gas distributor 3, around gas distributor 3, produce a large amount of bubbles immediately, also promptly around distributor 3, produce dilute-phase zone.The density of dilute-phase zone is less than fluid on every side.Under the percussion of density contrast and ejection gas, bubble moves upward along guide shell together with liquid, the solid particle of dilute-phase zone, and produces circulation movement, as shown in Figure 5.Continuing to rise at reactor head part gas enters gas-liquid separation zone, and another part gas then enters descending branch between guide shell and reactor wall with fluid.Thereby in descending branch, also exist certain gas content.Like this time of gas-liquid contact longer, absorb and can fully the carrying out of course of reaction.And in the scope below fluid flow export 4, owing to all there is the gas of certain content in the guide shell with annular space, the density of its mixed phase is low than neat liquid, thereby at fluid inflow entrance 5 places, the pressure P that fluid column produces
1Also the pressure that produces than the neat liquid fluid column of equal height is low.
At the reactor head gas-liquid separation zone, the gas that enters gas-liquid separation zone continues to rise, and finally overflows from the gas-liquid mixed phase, and discharges from the exhaust outlet of reactor head.Drop to descending branch through the partially liq after the gas-liquid separation, continue to participate in circulation; Another part liquid then flows into overflow launder 6.In overflow launder, liquid is static relatively, and a small amount of gas that contains in the liquid is further separated, thereby is substantially devoid of gas in the liquid that flow out overflow launder 6 bottoms, is neat liquid.When being full of liquid in the pipeline 8 and not considering the dynamic pressure of fluid, do not contain gas so, so the fluid column in the pipeline 8 is at the pressure P of fluid inflow entrance 5 places generation owing in the liquid
2Pressure P greater than the generation of the fluid column in the reactor
1Under the effect of pressure reduction, fluid overcomes drag stream from flow export 4 in the guide shell of another reactor along pipeline 8 and inflow entrance 5.In fact, owing to moving upward fast of gas in the guide shell and liquid, the pressure in inflow entrance 5 outsides will further reduce, and make the pressure difference of inflow entrance 5 inside and outside both sides further improve.
The speed that in pipeline 8, flows of the pressure difference of inflow entrance 5 inside and outside both sides and the big young pathbreaker's final decision of the resistance fluid of pipeline 8 (comprising pipe fitting).If the gas holdup of gas-liquid mixed phase in the raising reactor (entering the flow of the gas of reactor such as increase), then the pressure difference of inflow entrance 5 inside and outside both sides increases, thereby fluid flow rate improves.If use the pipeline smooth, that internal diameter is big 8 to connect two towers, and the resistance coefficient of the pipe fitting that adopts is less, then the mobile speed of fluid also will improve.
The pressure difference P of inflow entrance 5 inside and outside both sides in reactor A, B
AAnd P
BNot simultaneously, fluid is not different with regard to possibility from the flow that two reactors flow out.Under the identical situation of the resistance of the pipeline that connects two reactors, if Δ P
A<Δ P
B, the flow L of the fluid that then from reactor A, flows out (being the fluid of inflow reactor B)
AFlow L greater than the fluid that flows out among the autoreactor B (fluid of inflow reactor A)
B, then the liquid level in the reactor A will descend, and the liquid level in the reactor B will rise.This just makes Δ P
AIncrease, and Δ P
BReduce; Final Δ P
A=Δ P
B, and L
A=L
BPromptly the fluid communication amount equates that reactor assembly enters steady state operation in two reactors; Otherwise, if P
A>P
B, then the liquid level among the end reaction device A is the rising certain altitude, and reaches L
A=L
BSteady state operation.Thereby this reactor assembly has self-regulating performance, and promptly when operating parameter departs from stable state, reactor assembly will enter stable state automatically automatically by adjusting liquid level in two reactors.
Introduce several embodiments of the present invention below, but protection scope of the present invention is not limited to embodiment.
Embodiment 1: present embodiment be measuring the gas flow that enters reactor not simultaneously, the variation of circulation of fluid flow between two reactors.Guide shell in the reactor of the mensuration that experimentizes is 2 grades.The main structure parameters such as the table 1 of reactor.The material of reactor is a lucite, and the material of guide shell is a stainless steel.Pipeline 8 is a nylon pipeline, and pipe diameter 2cm has flowmeter in the pipeline.Measuring the liquid that is adopted is pure water, and gas is compressed air, and operating pressure is a normal pressure.Gas volume gas holdup in tower B remains unchanged (6%), and the volume gas holdup ε of gas among the tower A
ANot not simultaneously, the flow L of effluent fluid (fluid of inflow reactor A) among the autoreactor B
BVariation be plotted in the accompanying drawing 6.
Main structure parameters (the unit: mm) of table 1 reactor
Reactor |
The reactor height |
Reactor inside diameter |
The guide shell height |
The guide shell internal diameter |
The gas-liquid separation zone height |
?A |
?2000 |
?206 |
?1300 |
?158 |
?500 |
?B |
?2000 |
?120 |
?1300 |
?90 |
?500 |
Embodiment 2: present embodiment is for adopting reactor assembly of the present invention, removes hydrogen sulfide in the gas by absorption reaction, and absorbent is regenerated.This process is used iron-based technology, with complexing Fe
3+Catalyst for absorption reaction.Its absorption reaction and complexing iron Fe
2+Regenerative response as follows:
Absorption reaction is:
H
2S (dissolving)+2Fe
3+→ 2H
++ S ↓+2Fe
2+
Regenerative response is:
1/2O
2(dissolving)+H
2O+2Fe → 2OH
-+ 2Fe
3+Absorption reaction and regenerative response carry out in the circulation flow reactor B of circulation flow reactor A respectively.The distributor of H 2 S-containing gas autoreactor A enters reactor A, is being absorbed and and complexing Fe by the solution among the A
3+After the reaction, generate sulphur (S) and complexing Fe
2+The gas that removes hydrogen sulfide is discharged from the A top.The complexing Fe that forms in the reaction
2+Flow into reactor B with solution, feed compressed air or oxygen in the reactor B, complexing Fe
2+Again be oxidized to complexing Fe
3+, complexing Fe
3+Flow export from reaction B flows to reactor A again, and so iron ion can constantly recycle, and constantly is absorbed and reacts elimination by going into the hydrogen sulfide that is contained in the gas among the A.