CN1329353C - Reaction device for ethylbenzene dehydrogenation for making styrene - Google Patents

Abstract

The present invention relates to a reaction device for ethylbenzene dehydrogenation for making styrene, which mainly solves the problems in the present reaction systems of styrene industrial production devices that the arrangement of steps is unreasonable so overheaters frequently generate accidents during material reaction and material feeding, the reaction systems of the styrene industrial production devices can not safely work for long time, the pressure reduction or the heat loss in pipelines in the reaction system is large, etc. The present invention adopts two heat insulation catalytic dehydrogenation radial reactors or axial reactors connected in series and a middle heat exchanger which are arranged in the shape of pi; the middle heat exchanger is directly arranged at the top end of a second stage dehydrogenation reactor; a combined heat exchanger for discharging, cooling and heat recovering of a high temperature reactor is arranged in the shape of gamma. The heat exchanger at a high temperature section is vertically arranged; the two heat exchangers of the moderate temperature section and the low temperature section are horizontally arranged; thereby, the problems are well solved. The present invention can be used for industrial production of styrene by ethylbenzene dehydrogenation.

Description

Reaction device for ethylbenzene dehydrogenation for making styrene

Technical field

The present invention relates to the ethyl benzene dehydrogenation preparation of styrene device, specifically, relate to a kind of ethylbenzene negative pressure adiabatic catalytic dehydrogenation preparation of styrene reactive system two radially placed in-line or axial-radial flow reactor and intermediate heats and three interchanger that are used for reactor high temperature discharging cooling and heat recuperation, the device of the connection of totally six key equipments and flow process of being used for.

Background technology

The present invention is to the further improvement of the Chinese patent ZL02265400.3 " high temperature sensible heat reclaim unitized exchanger " (on June 12nd, 2003 was authorized to) of our invention and replenishes.

Described in the Chinese patent ZL02265400.3, vinylbenzene has purposes widely as a kind of important chemical material commodity, and is growing to its demand as us, and its industrial production has obtained to develop rapidly.

In all multi-styrene industrial processes, be most widely used, technology is the most ripe, economy the most reasonably operational path when being that vinylbenzene is made in ethylbenzene dehydrogenation.This production technology is continually developed research through for many years, from early stage emphasis catalyzer development, develop into improvement catalyzer and installation optimization and lay equal stress on, especially payes attention to reducing the material consumption and the energy consumption of unit styrene product, improves competitiveness.At present, the vinylbenzene industrial production generally adopts the negative pressure adiabatic dehydrogenation technology with inter-stage second-heating two-stage series connection reactor, and device is tending towards maximizing, automatization, and raw material consumption and energy consumption descend significantly.

It is that a strong heat absorption increases the molecule reversible reaction that ethylbenzene dehydrogenation generates vinylbenzene, and high temperature and low pressure help this reversible reaction and carries out towards generating cinnamic direction.This two-stage series connection negative pressure thermal insulation that has the inter-stage second-heating just radially (or the diameter of axle to) reactor assembly obtains the reason place of widespread usage in the ethyl benzene dehydrogenation preparation of styrene industrial production.Because the beds of this radially (or the diameter of axle to) adiabatic reactor is thinner relatively, under the reaction mass prerequisite identical by the beds air speed, radially the pressure drop of (or the diameter of axle to) adiabatic reactor is starkly lower than the pressure drop of the thicker relatively calandria type fixed bed big device isothermal reactor of beds, thereby radially (or the diameter of axle to) adiabatic reactor more helps forming the negative pressure operating mode of condition of high vacuum degree.In addition, be provided with intermediate heat between two of this reactor assemblies placed in-line radially (or the diameter of axle to) adiabatic reactor, available hyperthermia and superheating water vapour has dropped to 500～570 ℃ material enforcement heating for the second time to temperature carry out the adiabatic dehydrogenation reaction in first step reactor (hereinafter to be referred as " is anti-") after, make material be warmed up to 580～650 ℃ again, and enter second stage radial reactor (hereinafter to be referred as " two is anti-"), proceed the adiabatic dehydrogenation reaction, thereby charging ethylbenzene can be realized higher transformation efficiency.

As mentioned above, the advantage of this two-stage series connection reactor negative pressure adiabatic dehydrogenation reactive system with inter-stage second-heating is unquestionable, but just face two key technical problems thereupon: the one, how reasonably the high-temperature reactor discharging that is in negative pressure to be cooled down, and with its heat recovery and utilization, to reduce the comprehensive energy consumption of product; The 2nd, how to make the type selecting and the layout that are used to reclaim high-temperature reactor discharging heat and make it the refrigerative heat-exchange equipment satisfy high-level efficiency and low pressure drop requirement, the negative pressure operating mode of realization response system better.

At above-mentioned two technical problems, the ethyl benzene dehydrogenation preparation of styrene full scale plant generally adopts unitized exchanger to reclaim the heat of high-temperature reactor discharging at present, makes it rapid cooling.Our Chinese patent ZL022654003 has proposed the unitized exchanger (as shown in Figure 3) of a kind of layout general layout for " L " type; " petrochemical equipment technology " 2000 21 5 phases of volume the 6th page of unitized exchanger (as shown in Figure 1) of then having reported another kind of layout general layout for " one " font.This unitized exchanger that has been used for some ethyl benzene dehydrogenation preparation of styrene full scale plants shown in Figure 1 is by three end to end being in series of horizontally-arranged tube and shell heat exchanger.The advantage of this flow arrangement is: can enter horizontally-arranged " one " font unitized exchanger with very short distance from the effusive high-temperature reactor discharging of " two is anti-" lower side, and three tube and shell heat exchanger housings are end to end in " one " font unitized exchanger, there is not connecting tube therebetween, make area of dissipation dwindle, also greatly the reducing along the journey crushing of high-temperature reactor discharging in the tube side reaches the purpose that reduces heat lost by radiation and tube side pressure drop.Yet, production practice are found, still there are many shortcomings in this flow arrangement, " petrochemical equipment technology " rolled up the 6th page of 5 phase in 2000 21 and this made report: the tube bank of the high temperature section reactor feed superheater (parts 7 among Fig. 1) of this unitized exchanger is damaged repeatly, cause the superheater equipment failure, repeatedly be forced to stop, become the bottleneck that restriction is produced.When being done strip inspection, this equipment finds, its temperature end has the butt weld fracture between 187 same stationary tubesheets of tubulation (parts 6 among Fig. 1), cause thus that material leaks mutually between tube side and the shell side, and disconnected pipe concentrates on zone on the upper side, stationary tubesheet center, and pocketed distortion then appears in stationary tubesheet self.This accident also happens occasionally on the same device of other factory.Though factory takes corresponding remedial measures, still can keep production, the disadvantage of this flow arrangement is completely exposed, should fundamentally address this problem.

Superheater in the analysis chart 1 (parts 7), this tube and shell heat exchanger temperature end are stationary tubesheet (parts 6 among Fig. 1), and low-temperature end is a stuffing box formula slip tube sheet (parts 9 among Fig. 1).Behind the device normal operation input, this heat exchanger tube mean wall temperature reaches 450 ℃, and the housing mean wall temperature only is 315 ℃, have the big temperature difference between the two, thereby difference appears in both thermal expansion amounts, calculates the thermal expansion amount difference and reaches 20 millimeters.If the tube bank and the thermal expansion of housing can not get coordination, will cause this structure deteriorate and lost efficacy.For this reason, the low-temperature end of this interchanger is designed to stuffing box formula slip tube sheet, when tube bundle heat swell increment and housing thermal expansion amount are inconsistent, just can slide and is coordinated by means of the front and back of slip tube sheet.As long as the difference of the radial thermal expansion amount of considering the slip tube sheet again and the radial thermal expansion amount of housing, the suitable annular space (being pressed into the temperature resistant encapsulation filler in the annular space) of reservation width between slip tube sheet outer rim and inner walls, as if so this structure justifiable.But this design is that level is horizontally-arranged and influence that produce is underestimated to this interchanger obviously.In fact, in case the temperature end of this tube and shell heat exchanger adopts stationary tubesheet, low-temperature end adopts stuffing box formula slip tube sheet, and it is the horizontal boom beam of fulcrum with the stationary tubesheet that whole tube bank just is equivalent to one.Because the effect of tube bank self gravitation must be to the fulcrum of this horizontal boom beam, promptly tubulation produces a gravitational torque with the root of stationary tubesheet welding.Under the effect of this gravitational torque, the tubulation root on the stationary tubesheet center will be subjected to tensile stress, and the tubulation root under the stationary tubesheet center is compression chord then.With regard to the example of above-mentioned generation leakage accident, this tube and shell heat exchanger is 38 millimeters * 2.1 millimeters heat transfer tubes of 870 φ altogether, and pipe range reaches 8.8 meters, and the tube bank diameter is about 1.3 meters, reaches about 15 tons together with the weight of tube sheet in interior whole tube bank.The mean wall temperature of tube bank causes the rigidity variation of tubulation material again up to 450 ℃.At this moment, this root socle girder is bent downwardly, and makes its free end slip tube sheet sagging, thereby the slip tube sheet is pressed the lock packing in its below annular space very tightly, causes free-ended slip tube sheet to be difficult to endwisely slip along housing.Otherwise slip tube sheet top annular space width then enlarges owing to beam free end is sagging, may produce the slit between lock packing and the inner walls, causes tube side material and the mutual seepage of shell side material.

When device stopped, this interchanger slowly cooled off, and gradually to the normal temperature recovering state, wherein tube bank is also slowly shunk, towards packaging recovery.In this recovery process, because the influence that thermal expansion causes under the high temperature attitude can not synchronism eliminates, especially the constraint that the tube sheet that slides is subjected to still exists, causing tubulation to shrink is restricted, the obstruction that the top tubulation contraction that thermal expansion is bigger under the high temperature attitude in the tube bank is subjected to is particularly serious, they are subjected to bigger tensile stress, (tubulation of aforementioned 187 fractures mostly concentrates on zone on the upper side, stationary tubesheet center so just the root a little less than its intensity relative thin (commissure that tubulation connects with stationary tubesheet) ruptures, just fully proved this point), cause material more serious between tube side and the shell side to leak mutually, thereby make the inefficacy that paralyses of whole superheater.

In addition, in the flow arrangement of Fig. 1, the discharging of " two is anti-" sidewall opening is a kind of unavoidable mode that can take to link to each other with " one " font unitized exchanger than the short tube line in order to yield to, and this pressure drop to uniform fluid distribution and " two is anti-" in " two is anti-" has caused detrimentally affect.As everyone knows, for fixed-bed reactor radially, by its vertical pivot centre opening advance/discharging is the most reasonable, only this help most material radially towards around (or center) evenly flow.When radial fixed-bed catalyticreactor is taked the sidewall opening discharging, then material radially passes through fixed bed from the pipe core runner and enters the process of outer shroud runner, and it is unavoidable to produce bias current.Unless the backstop of fixed bed both sides is radially adopted special measures such as inhomogeneous percentage of open area (certainty of these measures is limited), usually always the reaction mass that beds passed through the closer to sidewall discharge port position is many more, and the reaction mass that beds passed through away from sidewall discharge port position is few more more.This bias current causes the catalyst loading difference at each position, and catalyzer is difficult to obtain even utilization, and this one abstaining from greatly of catalyticreactor just.

Another defective of " two is anti-" sidewall discharging is: because the annular space width of outer shroud runner is limited, material is pasting wall and is flowing and compile to the sidewall opening place, in case arrive the sidewall opening place, just unexpected 90 ° of urgency inflow outlet conduit that turns round.This mobile coefficient of partial resistance is quite big, causes the local pressure loss at this position to increase suddenly, is unfavorable for forming in the reactor high vacuum negative pressure operating mode.

In our Chinese patent ZL02265400.3 (referring to Fig. 3), the ethyl benzene dehydrogenation preparation of styrene device reaction system flow of Fig. 1 pattern has been arranged and improved, reaction mass is comprising that being " N " type flow arrangement between three equipment of two reactors and intermediate heat flows, and two reactors all advance/discharging at the position, axis, and the bias current phenomenon of Fig. 1 flow arrangement can not take place; Unitized exchanger is then taked " L " type flow arrangement, and wherein superheater (parts 207 among Fig. 3, are equivalent to parts 7 among Fig. 1) is vertically perpendicular puts, and has overcome in Fig. 1 flow arrangement its horizontally-arranged shortcoming.But connecting tube is oversize before and after the intermediate heat of " N " type flow arrangement, and it is also many to turn round, and not only area of dissipation is bigger, thereby heat lost by radiation is bigger, and also bigger along the stroke pressure loss, so need further optimize its flow arrangement.

Summary of the invention

Technical problem to be solved by this invention is to relate in the document and patent of ethyl benzene dehydrogenation preparation of styrene device reaction system flow layout in the past, the high temperature section ethylbenzene superheater of " one " font unitized exchanger existence damages easily as shown in Figure 1, " two is anti-" sidewall discharging shock resistance is big and make its internal flow produce defectives such as bias current, and the reactor assembly connecting tube that is " N " type flow arrangement and adopts " L " type unitized exchanger to exist is long as shown in Figure 3, flow pressure drop reaches shortcomings such as heat lost by radiation is big greatly, and a kind of new ethyl benzene dehydrogenation preparation of styrene device is provided.This device has can make even fluid distribution in two radial fixed-bed dehydrogenation reactors, the import/export shock resistance is little, connecting tube is short between " one is anti-", intermediate heat and " two is anti-", heat lost by radiation is few, be convenient to that the most abominable superheater bank of operational conditions freely stretches in the unitized exchanger, be difficult for taking place the characteristics of leakage accident.

For solving the problems of the technologies described above, the technical solution used in the present invention is as follows:

A kind of reaction device for ethylbenzene dehydrogenation for making styrene, comprise that successively first dehydrogenation reactor 102, second dehydrogenation reactor 104, the high temperature sensible heat that is composed in series by high temperature section interchanger 107, middle warm area section interchanger 110 and low temperature section interchanger 112 successively reclaim unitized exchanger, wherein first dehydrogenation reactor 102 and 104 of second dehydrogenation reactors are " ∏ " type and are connected in series; Second dehydrogenation reactor 104 is " U " type with high temperature section interchanger 107 and is connected in series; The angle α that the medullary ray of high temperature section interchanger 107 and middle warm area section interchanger 110 forms is 60～135 °, and preferred value is α=90 °; In warm area section interchanger 110 be 135～270 ° with angle β that low temperature section interchanger 112 both medullary rays form, preferred value is β=180 °; Also be provided with intermediate heat 103 between first dehydrogenation reactor 102 and second dehydrogenation reactor 104, and be positioned at second dehydrogenation reactor, 104 tops, intermediate heat 103 is same medullary ray with second dehydrogenation reactor 104 and is connected.

In the technique scheme, merge by main steam 101 with through superheated vaporization ethylbenzene raw material 116, temperature is 580～650 ℃, pressure is the static mixer that the reactor feed of 60～120kPaA enters " one is anti-" 102 belows, vaporization ethylbenzene and high-temperature vapor are after this thorough mixing is even, enter " one is anti-" 102 pipe cores from bottom to top, radially beds is in the form of a ring passed through in shunting, chemical reaction such as ethylbenzene dehydrogenation takes place and be cooled to 500～570 ℃, then the outer shroud runner between inflow catalyst bed and the reactor shell inwall, confluxing derives to centre, " one is anti-" 102 top, be the pipe connecting of " ∏ " type through having corrugated-type expansion joint 105, enter intermediate heat 103 tube sides, again be warming up to 580～650 ℃ with the high-temperature vapor indirect heat exchange of 103 shell sides, and directly enter " two is anti-" 104 tops downwards, then radially shunt beds by in the form of a ring along the outer shroud runner of " two is anti-", be cooled to 500～570 ℃ once more behind the chemical reactions such as generation ethylbenzene dehydrogenation, pressure is then reduced to 40～100kPaA, and conflux to the pipe core runner of " two is anti-", derive by the outlet at " two is anti-" center, lower end at last.Equipment layout general layout this " one is anti-" 102, intermediate heat 103 and " two is anti-" 104 is " ∏ " type, and the flowing-path that material flows through " is anti-" 102, intermediate heat 103 and " two is anti-" 104 successively also is " ∏ " type flow arrangement generally.

" U " type nipple (device floor plan allow under, as far as possible short) of the effusive reactor discharging of " two is anti-" 104 lower end central outlet through having expansion joint 105 enters the perpendicular tube side of putting superheater 107 of unitized exchanger high temperature section from bottom to top.Superheater 107 is that a bottom temperature end is a stationary tubesheet, and the top low-temperature end is the tube and shell heat exchanger of stuffing box formula slip tube sheet, can be if do not establish corrugated-type expansion joint (but the manufacturing of major diameter corrugated-type expansion joint is relatively more difficult) on its housing.It is 95～120 ℃ the vaporization ethylbenzene and the vapour mixture 108 of preparing burden that superheater 107 its shell sides feed temperature, heat exchange between pipe/shell side material, the temperature that shell side flows out material 116 rises to 400～550 ℃, after it and main steam 101 are converged, together enters the static mixer of " one is anti-" 102 belows." two is anti-" 104 dischargings of superheater 107 tube sides then are cooled to 300～400 ℃, and flow out from superheater 107 tops, through having the nipple of 90 ° of elbows, horizontally-arranged by level successively and the low-pressure steam waste heat boiler 110 (producing 0.3～0.4MPaG low-pressure steam) and the low low-pressure steam waste heat boiler 112 (produce 0.035～0.045MPaG and hang down low-pressure steam) that fuse.Reactor discharging 115 finally is cooled to 110～140 ℃, through having the derivation pipeline of expansion joint 114, transports to separation and purification and recovery system.

Be " Γ " type by the join end to end equipment layout general layout of the unitized exchanger that forms of superheater 107, low-pressure steam waste heat boiler 110 and 112 3 tube and shell heat exchanger of low low-pressure steam waste heat boiler, the flow through flowing-path of this unitized exchanger of " two is anti-" discharging also is " Γ " type flow arrangement.

Description of drawings

Fig. 1 is a kind of ethyl benzene dehydrogenation preparation of styrene device synoptic diagram that some factories have adopted.

Fig. 2 is an ethyl benzene dehydrogenation preparation of styrene device synoptic diagram of the present invention.

Fig. 3 is the ethyl benzene dehydrogenation preparation of styrene device synoptic diagram of our Chinese patent ZL02265400.3.

In Fig. 1,1 is main steam; The 2nd, first step adiabatic catalytic dehydrogenation radial reactor (being called for short " is anti-"); The 3rd, intermediate heat; The 4th, second stage adiabatic catalytic dehydrogenation radial reactor (being called for short " two is anti-"); The 5th, corrugated-type expansion joint; The 6th, the stationary tubesheet of reaction feed ethylbenzene superheater; The 7th, the high temperature section of unitized exchanger-reaction feed ethylbenzene superheater; 8 is reaction feed (vaporization ethylbenzene and batching vapour mixture); The 9th, the slip tube sheet of reaction feed ethylbenzene superheater; The 10th, the middle warm area section-low-pressure steam waste heat boiler of unitized exchanger; 11 is low-pressure steam; The 12nd, the low temperature section of unitized exchanger-low low-pressure steam waste heat boiler; 13 are low low-pressure steam; The 14th, corrugated-type expansion joint; 15 is through the cooled reactor discharging of unitized exchanger; 16 is by the reaction feed after the superheater heating (vaporization ethylbenzene and batching vapour mixture); The 17th, stationary bearing; The 18th, sliding support; 19 is feedwater; 20 is feedwater.

In Fig. 2, for the ease of comparing with Fig. 1, its numbering is basic corresponding with Fig. 1, just the numbering among Fig. 1 is added " 100 ", as corresponding numbers among Fig. 2.For example, the numbering 107 among Fig. 2 is just corresponding to the numbering among Fig. 17, and surplus person analogizes.

Among Fig. 2,101 is main steam; The 102nd, first step adiabatic catalytic dehydrogenation radial reactor (being called for short " is anti-"); The 103rd, intermediate heat; The 104th, second stage adiabatic catalytic dehydrogenation radial reactor (being called for short " two is anti-"); The 105th, corrugated-type expansion joint; The 106th, the stationary tubesheet of reaction feed ethylbenzene superheater; The 107th, the high temperature section of unitized exchanger-reaction feed ethylbenzene superheater; 108 is reaction feed (vaporization ethylbenzene and batching vapour mixture); The 109th, the slip tube sheet of reaction feed ethylbenzene superheater; The 110th, the middle warm area section-low-pressure steam waste heat boiler of unitized exchanger; 111 is low-pressure steam; The 112nd, the low temperature section of unitized exchanger-low low-pressure steam waste heat boiler; 113 are low low-pressure steam; The 114th, corrugated-type expansion joint; 115 is through the cooled reactor discharging of unitized exchanger; 116 is by the reaction feed after the superheater heating (vaporization ethylbenzene and batching vapour mixture); The 117th, stationary bearing; The 118th, sliding support; 119 is feedwater; 120 is feedwater.

In Fig. 3, for the ease of comparing with Fig. 1 and Fig. 2, its numbering is basic corresponding with Fig. 1 and Fig. 2, just adds " 200 ", as corresponding numbers among Fig. 3.201 is main steam among this figure; The 202nd, first step adiabatic catalytic dehydrogenation radial reactor (being called for short " is anti-"); The 203rd, intermediate heat; The 204th, second stage adiabatic catalytic dehydrogenation radial reactor (being called for short " two is anti-"); The 205th, corrugated-type expansion joint; The 206th, the stationary tubesheet of reaction feed ethylbenzene superheater; The 207th, the high temperature section of unitized exchanger-reaction feed ethylbenzene superheater; 208 is reaction feed (vaporization ethylbenzene and batching vapour mixture); The 209th, the slip tube sheet of reaction feed ethylbenzene superheater; The 210th, the middle warm area section-low-pressure steam waste heat boiler of unitized exchanger; 211 are circulation ethylbenzene; 212 is fresh ethylbenzene; 213 are batching steam; The 214th, the low temperature section of unitized exchanger-ethylbenzene vaporizer; 215 is through the cooled reactor discharging of unitized exchanger; 216 is by the reaction feed after the superheater heating (vaporization ethylbenzene and batching vapour mixture); The 217th, stationary bearing; The 218th, sliding support; The 219th, drum; 220 is feedwater; 221 is low-pressure steam.

Below by embodiment and comparative example, from three aspects such as the pressure drop of the operation conditions of unitized exchanger high temperature section reaction feed superheater, reactive system connecting tube and heat lost by radiationes, the present invention is further elaborated.

Embodiment

[embodiment]

According to the present invention, have " ∏ " type reactor assembly flow arrangement of 60,000 tons of/year styrene device ethylbenzene dehydrogenation unit process system designs of negative pressure adiabatic catalytic dehydrogenating technology of inter-stage second-heating two-stage series connection radial reactor and " Γ " type unitized exchanger flow arrangement for a certain employing as shown in Figure 2.

In the reactor assembly that is " ∏ " type flow arrangement, " one is anti-" 102 and " two is anti-" 104, the two is 3000 millimeters * 8000 millimeters radial fixed-bed reactors of φ, and their pipe core diameter is 1200 millimeters of φ, and the outer shroud width of flow path is 300 millimeters.Intermediate heat 103 directly is located in " two is anti-" 104 tops, links to each other with 42 inches pipelines that have corrugated-type expansion joint 105 between " one is anti-" 102 tops outlets and the intermediate heat 103 top imports, and its length is 9 meters.

In the unitized exchanger that is " Γ " type flow arrangement, perpendicular arm is a reaction feed superheater 107, and it is one section one way tube and shell heat exchanger, and its housing internal diameter is 1500 millimeters of φ.The transverse arm of " Γ " type unitized exchanger is low-pressure steam waste heat boiler 110 and the low low-pressure steam waste heat boiler 112 that housing directly links to each other, and these two sections also all is the one way tube and shell heat exchanger, and their housing internal diameter also all is 1500 millimeters of φ.

Link to each other with 42 inches pipelines that have corrugated-type expansion joint 105 between " two is anti-" 104 lower ends outlets and the 107 lower end imports of reaction feed superheater, its length is 8 meters.

It is that 250 millimeters expanded perlite product is incubated that thickness all use in two 42 inches connecting tubes outside.The location meteorological conditions is: 15 ℃ of annual mean temperatures, average of the whole year wind speed 3 meter per seconds.

" one is anti-" 102 outlet operating modes are: temperature T=541 ℃, and pressure P=52kPaA, volume of material flow V=162915 cubic meter/hour, density p=0.198 kilogram/cubic metre, viscosity, mu=0.028 centipoise.

" intermediate heat " 103 outlet operating modes are: temperature T=620 ℃, and pressure P=47kPaA, the volumetric flow rate v=197740 cubic meter of material/hour, density p=0.163 kilogram/cubic metre, viscosity, mu=0.029 centipoise.

" two is anti-" 104 outlet operating modes are: temperature T=577 ℃, and pressure P=42kPaA, volume of material flow V=220940 cubic meter/hour, density p=0.146 kilogram/cubic metre, viscosity, mu=0.03 centipoise.

By in 60,000 tons of/year styrene device ethylbenzene dehydrogenation unit process systems of Fig. 2 flow arrangement of the present invention, " ∏ " type 42 between outlet of " one is anti-" 102 tops and the intermediate heat 103 top imports " pressure drop of connecting tube (comprising its import/export shock resistance) Δ P ∏=0.444kPa, the heat lost by radiation Q ∏ of this connecting tube=3.4 kilowatts; Perpendicular " U " type 42 between reaction feed superheater 107 bottom inlet " pressure drop of connecting tube (comprising its import/export shock resistance) Δ PU=0.359kPa, the heat lost by radiation QU=4.01 of this connecting tube kilowatt put of the outlet of " two is anti-" 104 bottom centre and " Γ " type unitized exchanger high temperature section.The pressure drop of these two connecting tubes in the dehydrogenation reactor system (comprising its import/export shock resistance) adds up to Δ P=0.803kPa, and the heat lost by radiation of two connecting tubes adds up to Q=7.41 kilowatt.

This device was gone into operation operation since 8 years, and the perpendicular reaction feed superheater of putting 107 moves normally always, and the temperature that the reactor high temperature discharging enters superheater 107 tube sides is 564 ℃, and the temperature that superheater 107 tube sides are flowed out in the reactor discharging is 392 ℃; Reaction feed (vaporization ethylbenzene and batching vapour mixture) 108 temperature that enter superheater 107 shell sides are 100 ℃, is 505 ℃ by the reaction feed after the tube side high temperature discharging heating (vaporization ethylbenzene and batching vapour mixture) 116 from the effusive temperature of superheater 107 shell sides, meets design requirement.In 8 years, finding to erect between tube side/shell side of putting superheater 107 has interior leakage, and leakage accident does not take place.

[comparative example 1]

A certain employing has 60,000 tons of/year styrene device ethylbenzene dehydrogenation unit of the negative pressure adiabatic catalytic dehydrogenating technology of inter-stage second-heating two-stage series connection radial reactor, the flow arrangement of its reactive system as shown in Figure 1: " ∏ " type reactor assembly flow arrangement and " one " type unitized exchanger flow arrangement.

The processing condition and the equipment size of this device ethylbenzene dehydrogenation unit process system are all same as the previously described embodiments, and " ∏ " type connecting tube (9 meters of length) is connected short tube (2 meters of length) and also all adopts 42 inches pipelines with " one " font.The pressure drop of " ∏ " type connecting tube (comprising its import/export shock resistance) is same as the previously described embodiments, i.e. Δ P ∏=0.444kPa, and the heat lost by radiation of this connecting tube also is Q ∏=3.4 kilowatt.

The pressure drop (comprising its import/export shock resistance) that 42 inches levels between horizontally-arranged reaction feed superheater 7 imports of " two is anti-" 4 bottom side wall outlets and " one " type unitized exchanger high temperature section are connected short tube is up to 2.967kPa, is 8.27 times of pressure drop (comprising its import/export shock resistance) Δ PU of corresponding " U " type connecting tube in the foregoing description.The heat lost by radiation of this connection short tube is 0.81 kilowatt, only be in the foregoing description corresponding " U " type connecting tube heat lost by radiation 1/5.The pressure drop of two connecting tubes in this dehydrogenation reactor system (comprising its import/export shock resistance) adds up to Δ P=3.411kPa, is 4.25 times that the pressure drop (comprising its import/export shock resistance) of corresponding two connecting tubes in the foregoing description adds up to; The heat lost by radiation of two connecting tubes adds up to Q=4.21 kilowatt in this dehydrogenation reactor system, is 0.57 times that corresponding two connecting tubes add up to heat lost by radiation in the foregoing description.

The heat lost by radiation of two connecting tubes is more much smaller than the heat lost by radiation of corresponding two connecting tubes in the foregoing description in this dehydrogenation reactor system, system is because the horizontal connection tube between horizontally-arranged reaction feed superheater 7 imports of " two is anti-" 4 bottom side wall outlets and " one " type unitized exchanger high temperature section is very short, and this is the advantage of this flow arrangement.But, the pressure drop of two connecting tubes is but much bigger than embodiment in this flow arrangement, and its major cause is its " two is anti-" the 4th, the sidewall opening discharging, and fluid flows to sidewall opening along wall before this, in case the arrival opening part, just anxious suddenly turning round enters discharge pipe.This flow pattern up to 2.51, causes shock resistance herein very big at the coefficient of partial resistance ξ at sidewall opening place.By contrast, in the flow arrangement of the present invention shown in Figure 2, the shock resistance of " two is anti-" 104 bottom discharge mouths has improvement greatly, this is owing to the pipe core of discharge nozzle with " two is anti-" is on same the axis, and the two internal diameter is very nearly the same, thus the shock resistance of " two is anti-" 104 bottom discharge mouths very little (coefficient of partial resistance ξ only is about 0.24).

For ethylbenzene negative pressure adiabatic catalytic dehydrogenation preparation of styrene device, condition of high vacuum degree is a very important target in the realization response device, and this will ask between reactor and the vacuum pump on-way resistance the smaller the better.This shows that flow arrangement of the present invention shown in Figure 2 is more more reasonable than the flow arrangement of the comparative example as shown in Figure 11 that some factories have used.Simultaneously, " two is anti-" 4 sidewall openings of comparative example 1 be cannot say for sure radially bias current not occur in " two is anti-" 4, and this also is the shortcoming that should not ignore of comparative example 1 flow arrangement shown in Figure 1.

In comparative example 1 flow arrangement shown in Figure 1 on horizontally-arranged superheater 7 structures of " one " font unitized exchanger high temperature section all disadvantages narration arranged in that " background technology " of patent specification front part more.Practical operation situation is in the factory: after a new horizontally-arranged superheater 7 puts into operation, promptly leak between generating pipe/shell side before biennial device overhaul, often take in the overhaul tubulation that leaks is blocked and dealt with.Arrive the biennium of overhaul next time after this, leak gradually again between these horizontally-arranged superheater 7 pipe/shell sides, and more and more serious, cause superheater 7 to be in " operation " in spite of illness situation, the advancing/go out temperature of charge and all can not reach design objective of its pipe/shell side.In case leak rapid deterioration between the pipe/shell side, just have to stop completely, carry out emergency processing.Open this horizontally-arranged superheater 7 this moment, just can be observed the regional on the upper side many tubulations in said its temperature end stationary tubesheet of patent specification front " background technology " part (parts 6 among Fig. 1) center with the fracture of the butt weld between the stationary tubesheet, situations such as pocketed distortion then appear in stationary tubesheet self.So far, this horizontally-arranged superheater 7 damaged must renewal stage.Unreasonable on this flow arrangement is the most fatal defective of this horizontally-arranged superheater 7.By contrast, in the flow arrangement of the present invention shown in Figure 2 unitized exchanger high temperature section superheater 107 vertical erecting are put, make the tube bank of superheater be equivalent to one " pillar ", rather than " socle girder ", and it is even around gap length can keep between its slip tube sheet 109 and the inner walls, gap length is suitable in addition, can guarantee that superheater is in process of expansion and contraction, its tube bank flexible becomes all disadvantages that " socle girder " caused thereby overcome to restrain in the horizontally-arranged superheater 7 of comparative example 1 shown in Figure 1 freely.

[comparative example 2]

A certain employing has 60,000 tons of/year styrene device ethylbenzene dehydrogenation unit of the negative pressure adiabatic catalytic dehydrogenating technology of inter-stage second-heating two-stage series connection radial reactor, the flow arrangement of its reactive system as shown in Figure 3: " N " type reactor assembly flow arrangement and " L " type unitized exchanger flow arrangement.

The processing condition and the equipment size of this device ethylbenzene dehydrogenation unit process system are all same as the previously described embodiments, perpendicular " ∏ " type connecting tube between reaction feed superheater 207 top inlet (long 10 meters) of putting of the connecting tube of intermediate heat 203 front and back (long 10 meters respectively, totally 20 meters) and " two is anti-" 204 top center discharge port and " L " type unitized exchanger high temperature section also all adopts 42 inches pipes.The pressure drop of the connecting tube of intermediate heat 203 front and back (comprising its import/export shock resistance) is respectively 0.349kPa and 0.450kPa, and the heat lost by radiation of this root connecting tube adds up to 11kw; The perpendicular pressure drop (comprising its import/export shock resistance) of putting " ∏ " type connecting tube between reaction feed superheater 207 top inlet of " two is anti-" 204 top center discharge port and " L " type unitized exchanger high temperature section is 0.488kPa, and the heat lost by radiation of this root " ∏ " type connecting tube is 5.01 kilowatts.

In comparative example 2 flow arrangement shown in Figure 3, the pressure drop of three 42 inches connecting tubes (comprising its import/export shock resistance) adds up to 1.287kPa, is embodiment illustrated in fig. 2 1.59 times; Their heat lost by radiation adds up to 16.01kw, is embodiment illustrated in fig. 2 2.16 times.As seen, the no matter pressure drop (comprising its import/export shock resistance) of connecting tube, still the heat lost by radiation of connecting tube, all poor than embodiment illustrated in fig. 2, its reason is in the flow arrangement of comparative example 2 shown in Figure 3, intermediate heat 203 is placed with " one is anti-" and " two is anti-" is independent side by side, causes the connecting tube lengthening.

For comparative example 2 flow arrangement shown in Figure 3, in 60,000 tons of/year devices that have, intermediate heat 203 front and back connecting tubes adopt 30 inches pipes, and the connecting tube between " two is anti-" 204 and the superheater 207 adopts 42 " pipes.At this moment, the pressure drop of intermediate heat 203 front and back connecting tubes increases to 2.326kPa and 2.229kPa respectively, the pressure drop of the connecting tube between " two is anti-" 204 and the superheater 207 still is 0.488kPa, and the pressure drop of three connecting tubes adds up to 5.043kPa, is embodiment illustrated in fig. 2 6.28 times; The heat lost by radiation of intermediate heat 203 front and back connecting tubes is then reduced to 8.5 kilowatts, the heat lost by radiation of the connecting tube between " two is anti-" 204 and the superheater 207 still is 5.01 kilowatts, the heat lost by radiation of three connecting tubes adds up to 13.51 kilowatts, is embodiment illustrated in fig. 2 1.82 times.

With embodiment illustrated in fig. 2 similar, the device of comparative example 2 shown in Figure 3 is gone into operation and has been moved since the several years, and the perpendicular reaction feed superheater of putting 207 operations are normal always, do not occur leakage accident as yet.But " L " type unitized exchanger low-temperature zone has but the time fault, tubulation distortion to occur also to produce and leak among Fig. 3 as the ethylbenzene vaporizer 214 of material ethylbenzene vaporization.Its reason may be the shortage of heat of reactor discharging in ethylbenzene vaporizer 214 tube sides, and ethylbenzene can not all be vaporized in the shell side, causes in the batching air-flow and carries the ethylbenzene drop secretly, washes away the erosion heat exchanging pipe, causes tubulation to damage.In this flow arrangement, the heat that ethylbenzene vaporizer 214 is provided lacks regulating measure, and is unreasonable.And in embodiment illustrated in fig. 2 the unitized exchanger low-temperature zone as hanging down low-pressure steam waste heat boiler 112, other establishes steam heated ethylbenzene vaporizer, then flexibility and reliability more.

Now the pressure drop of above three's connecting tube, heat lost by radiation and operation conditions are summarized in following table, so that relatively.

	Embodiment	Comparative example 1	Comparative example 2
				Pipeline is along journey pressure drop Δ P, kPa	0.803	3.411	1.287
Heat dissipation of pipeline loss Q, kilowatt	7.41	4.21	16.01
				The unitized exchanger operation conditions	8 years are not bad	Superheater damaged serious in 4 years	The ethylbenzene vaporizer is perishable

Last table explanation, flow arrangement of the present invention is more reasonable.

Claims (5)

1, a kind of reaction device for ethylbenzene dehydrogenation for making styrene, comprise that successively first dehydrogenation reactor (102), second dehydrogenation reactor (104), the high temperature sensible heat that is composed in series by high temperature section interchanger (107), middle warm area section interchanger (110) and low temperature section interchanger (112) successively reclaim unitized exchanger, wherein are " ∏ " type between first dehydrogenation reactor (102) and second dehydrogenation reactor (104) and are connected in series; Second dehydrogenation reactor (104) is " U " type with high temperature section interchanger (107) and is connected in series; High temperature section interchanger (107) is 60～135 ° with the angle α of the medullary ray formation of middle warm area section interchanger (110); Middle warm area section interchanger (110) is 135～270 ° with angle β that both medullary rays of low temperature section interchanger (112) form.

2, according to the described reaction device for ethylbenzene dehydrogenation for making styrene of claim 1, it is characterized in that also being provided with intermediate heat (103) between first dehydrogenation reactor (102) and second dehydrogenation reactor (104), and be positioned at second dehydrogenation reactor (104) top, intermediate heat (103) is same medullary ray with second dehydrogenation reactor (104) and is connected; Link to each other by " ∏ " type pipeline that has corrugated-type expansion joint (105) between first dehydrogenation reactor (102) and the intermediate heat (103); Link to each other by " U " type pipeline that has corrugated-type expansion joint (105) between second dehydrogenation reactor (104) and the high temperature section interchanger (107).

3,, it is characterized in that the high temperature section interchanger (107) and the angle α of the medullary ray formation of middle warm area section interchanger (110) are 90 ° according to the described reaction device for ethylbenzene dehydrogenation for making styrene of claim 1; Middle warm area section interchanger (110) is 180 ° with angle β that both medullary rays of low temperature section interchanger (112) form.

4, according to the described reaction device for ethylbenzene dehydrogenation for making styrene of claim 1, it is characterized in that first dehydrogenation reactor (102) for the adiabatic catalytic dehydrogenation radially or axial-radial flow reactor, second dehydrogenation reactor (104) be the adiabatic catalytic dehydrogenation radially or axial-radial flow reactor.

5,, it is characterized in that high temperature section interchanger (107), middle warm area section interchanger (110) and low temperature section interchanger (112) are the one way tube and shell heat exchanger according to the described reaction device for ethylbenzene dehydrogenation for making styrene of claim 1.

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