A kind of pyrolyzer of two-stroke radiation furnace tube
Technical field
The present invention relates to a kind of ethane cracking furnace of two-stroke radiation furnace tube.
Background technology
In ethylene unit, pyrolyzer is a nucleus equipment.The design of radiating furnace tube is a decision cracking selectivity, improves cracking product olefin yields and improves the adaptive key of different cracking stocks.Improve the structure of radiant coil and arrange, become part most crucial in the tube cracking furnace technical development.Over more than 20 year, single branch adapter bonnet, mixing branch adapter bonnet, the radiating furnace tube of different structure such as branch's adapter bonnet, the isometrical pipe of one way have not appearred in succession.
The arrangement mode of boiler tube singlely develops into doublely from initial, and for single, identical ability needs bigger floor space, and its advantage is the circumferential uniformity of temperature profile of boiler tube, exists the situation of covering less; For double, dwindled the floor space of pyrolyzer greatly, but the situation of covering is more serious, influenced the circumferential temperature distribution of boiler tube.
Adopt two journey boiler tubes such as 4-1,5-1,6-1, common four group's boiler tubes are joined a chilling (used heat) boiler;
Adopt 1-1 (U) type boiler tube, a common group or two group's boiler tubes are joined a linear chilling (used heat) boiler, all the bottom heat supply;
Adopt 2-1 two journey boiler tubes, common eight group's boiler tubes are joined a chilling (used heat) boiler; EP1146105 discloses the pyrolyzer that such boiler tube structure is arranged: the two-range radiant section boiler tube arranged vertical is in the radiation section burner hearth, the straight tube of one journey pipe and two journey pipes is arranged in the plane, one Cheng Zhiguan is connected by Guan Yuyi bend pipe of S shape respectively with two journey pipes, the S shape pipe of one journey pipe and two journey pipes is parallel respectively, bridge piece can be semicircle, half elliptic or semioval shape, and each bend pipe is identical with plane, straight tube place angulation.
For making raw material consumption reduce, keep suitable running period greatly and having adaptability to raw material preferably, present most of companies all adopt two journeys, and (18~28m) branch's reducings or two journey reducing highly selective boiler tubes will be controlled at 0.15~0.25s the residence time.The first Cheng Caiyong minor diameter boiler tube utilizes the big characteristics of its specific surface area to reach the purpose that is rapidly heated, and the larger-diameter boiler tube of second Cheng Caiyong is to reduce the influence to coking susceptibility.The two journey highly selective radiant coils that adopted have boiler tubes such as 1-1 type (U type), 2-1 type, 4-1 type, 5-1 type, 6-1 type, 8-1 type.1-1 type (U type) two journey boiler tubes have bigger specific surface area, have mechanical property preferably, but the cycle of operation is shorter than other two journeys boiler tubes.2-1 type two journey boiler tubes have bigger specific surface area, will grow but compare radiation section burner hearth length with 1-1 type boiler tube.
Summary of the invention
The purpose of this invention is to provide a kind of novel ethane cracking furnace of arranging.
The ethane cracking furnace of two-stroke radiation furnace tube of the present invention comprises high pressure drum 1, convection zone 2, radiation section 3, is arranged vertically many groups radiating furnace tube 4, burner 5, quenching boiler 6 at radiation section; Form the vertical radiating furnace tube of each two journey by the first journey pipe and the second journey pipe, between the first journey pipe and the second journey pipe, adopt the return bent pipe web member to connect; The cracking material is introduced by the first journey pipe, is drawn by the second journey pipe;
The first journey pipe of wherein said radiating furnace tube comprises: straight tube that two root entry pipes 7, threeway member 8, length are L 9, bend pipe 10, wherein L>0; Its top is two root entry pipes, after merging by a threeway member, fixedlys connected with a straight tube, fixedlys connected with an end of described return bent pipe web member 11 by a bend pipe again;
The second journey pipe of described radiating furnace tube comprises: an outlet pipe 13, and fixedly connected with the other end of described return bent pipe web member by a bend pipe 12 in its lower end;
Wherein said bend pipe can become as a whole with the return bent pipe web member;
Described return bent pipe web member is a three-dimensional arrangement part, is the plane of symmetry with the plane E at described radiating furnace tube place, and its side-looking is projected as a symmetric continuous curve;
The bend pipe 10 of the described first journey pipe and the bend pipe 12 of the second journey pipe are crooked in two plane F and G respectively; The side-looking projection of the bend pipe of the preferred described first journey pipe and the bend pipe of the second journey pipe is a plane of symmetry symmetry with plane E;
The centre symmetry line of the first all journey pipe of one group of radiating furnace tube and the medullary ray of the second journey pipe are in the E of plane;
The plane that the medullary ray of the centre symmetry line that wherein said plane E is the first journey pipe and the second journey pipe constitutes; Described plane F, plane G are the vertical planes of the angle that becomes non-vanishing with plane E.
In the optimal technical scheme of the present invention, the downward projection of each root bend pipe 10 of the first journey pipe of each group radiating furnace tube is not parallel to each other, and each root bend pipe 10 residing plane F becomes non-vanishing angle with plane E, and preferred range of angles is the 30-90 degree; The downward projection of each root bend pipe 12 of the second journey pipe is not parallel to each other, and each root bend pipe 12 residing plane G is vertical with plane E.
In another optimal technical scheme of the present invention, the downward projection of the bend pipe 12 of the described second journey pipe is parallel to each other, and each root bend pipe 12 residing plane G is vertical with plane E; The downward projection of the bend pipe 10 of the described first journey pipe is not parallel to each other, and each root bend pipe 10 residing plane F and different with the angle of plane E, and preferred range of angles is the 30-90 degree.
In another optimal technical scheme of the present invention, bend pipe 12 downward projections of the downward projection of the bend pipe 10 of the first journey pipe of a boiler tube of described one group of radiating furnace tube and the second journey pipe of same boiler tube or another boiler tube are parallel to each other.
The length of two root entry pipes of the first journey pipe of described radiating furnace tube is at least 10% of the first journey pipe total length, is 90% to the maximum; Preferred 10%-80%, more preferably 20-60%; The wherein said first journey pipe total length is for to enter radiation section from inlet tube, to the vertical range between the return bent pipe web member.The length of 2 root entry pipes that is about to the first journey pipe of traditional 2-1 type boiler tube suitably shortens, and with the top 2 root entry Guan Shangyi of traditional 2-1 type boiler tube first Cheng Guanzi, the boiler tube of this configuration is referred to as the 2/1-1 type.2/1-1 type boiler tube combines the advantage of 2-1 type boiler tube and 1-1 type boiler tube, has overcome the shortcoming of traditional 2-1 type boiler tube and 1-1 type boiler tube.
The preferred described first journey pipe comprises two parallel inlet tubes, and the plane of its composition overlaps or intersect a non-vanishing angle with plane E.Promptly two root entry pipes can with E plane, plane in be that the center rotates a certain angle with the symmetrical center line.
In embodiments of the invention, the return bent pipe web member parallel arrangement of described each radiating furnace tube, and downward projection is that a straight-line segment, length are identical; Described return bent pipe web member is arc, semicircle, half elliptic or parabola shaped web member, but is not limited only to listed shape.
In the radiation chamber of pyrolyzer of the present invention, can be arranged vertically many group radiating furnace tubes, one group of radiating furnace tube is made up of the described boiler tube of some amount.
Preferred described one group of radiating furnace tube comprises 2-12 described radiating furnace tube, and all first journey pipes of every group of radiating furnace tube are arranged in together with all second journey pipes are concentrated respectively.
In concrete enforcement, the adjacent layout of the second journey pipe of two groups of radiating furnace tubes can be constituted a module; A plurality of described modules of arranging again.In same module, the return bent pipe web member of two groups of radiating furnace tubes can the parallel or layout that forms an angle.
Also can be with the adjacent layout of the second journey pipe of the first journey pipe of one group of boiler tube and another group boiler tube.
The plane E at radiating furnace tube place is not same plane on the same group.
Guide frame can be selected whether be provided with according to concrete performance in bottom at the return bent pipe web member of radiating furnace tube of the present invention; Described guide frame can be guide pipe and pilot hole; Also can be that guide pipe combines with guide path.Be provided with the vertical guide pipe of furnace bottom and can prevent that boiler tube from departing from the central position.
At radiating furnace tube of the present invention, first, second journey boiler tube caliber can reducing.
The burner of pyrolyzer of the present invention can be provided with the associating of full base burning device or bottom and sidewall as required.
Quenching boiler of the present invention arranges that looking actual needs can be arranged in radiation section top or the side opposite with convection zone.
Quenching boiler has traditional type (Si Mite, Bao Xige), bathtub formula one-level quenching boiler, two telescoping (secondary chilling, linear quenching boiler); In the concrete enforcement of pyrolyzer of the present invention, because linear quenching boiler has the long advantage that does not need hydraulic decoking running period; Therefore in the enforcement of pyrolyzer of the present invention,, be complementary with linear quenching boiler preferably with radiant coil.As when joining the one-level quenching boiler, then the second journey pipe need merge.
The selection of boiler tube diameter and spacing is optimized according to performance.Generally speaking, the internal diameter of the first journey pipe can be selected in 35mm to 60mm; The internal diameter of the second journey boiler tube can be selected in 50mm to 85mm.
In the specific implementation, adopt how much organize boiler tube, relevant with the pyrolyzer ability, can determine according to design requirementss such as raw material condition, pyrolyzer output, the cycles of operation.
In pyrolyzer of the present invention, described radiant coil can be provided with enhanced heat transfer member according to actual needs.As the disclosed twisted tube of CN1260469.
The beneficial effect that the present invention reached is:
1, in the pyrolyzer of the present invention, in the furnace cavity of same length, the present invention can place more groups of boiler tubes, thereby bigger throughput is provided.
2, the boiler tube of pyrolyzer employing of the present invention has overcome the shortcoming of 1-1 type boiler tube weak point running period and 2-1 type boiler tube bad mechanical property; Thereby this kind boiler tube configuration also has the advantage of length running period, good mechanical property.
3, the radiant coil mechanical property that adopts of pyrolyzer of the present invention is improved, and prolongs 2~3 years work-ing life of boiler tube.
Description of drawings
Fig. 1 is the pyrolyzer synoptic diagram of 2/1-1 type boiler tube of the present invention.
Fig. 2, Fig. 3, Fig. 4 are diagrammatic elevation view, side-view, the vertical view of one group of 2/1-1 radiating furnace tube of the present invention; In the angled vertical plane of the two root entry Guan Zaiyu plane E of the first journey pipe A of radiating furnace tube; And the bend pipe of the second journey pipe B of radiating furnace tube with the angled plane G of plane E in crooked.
Fig. 5, Fig. 6, Fig. 7 are diagrammatic elevation view, side-view, the vertical view of one group of 2/1-1 radiating furnace tube of the present invention; In the angled vertical plane of two root entry Guan Zaiyu plane E of the first journey pipe of radiating furnace tube; The bend pipe of the first journey pipe of radiating furnace tube with the angled plane F of plane E in crooked.
Fig. 8 makes up the vertical view of the layout synoptic diagram of arranging for two groups of 2/1-1 type radiating furnace tubes of the present invention; The plane, two root entry pipe places of the first journey pipe A becomes non-vanishing angle with plane E, the bend pipe of the second journey pipe B of radiating furnace tube with the angled plane G of plane E in crooked; The adjacent layout of the second journey pipe B of the first journey pipe A of one group of radiating furnace tube and another group radiating furnace tube, and the return bent pipe web member of two groups of radiating furnace tubes is parallel.
Fig. 9 makes up the vertical view of the layout synoptic diagram of arranging for two groups of 2/1-1 type radiating furnace tubes of the present invention; The plane, two root entry pipe places of the first journey pipe A becomes non-vanishing angle with plane E, the bend pipe that the second journey pipe B of radiating furnace tube connects with the angled plane G of plane E in crooked; The adjacent layout of the second journey pipe B of two groups of radiating furnace tubes, and the return bent pipe web member of two groups of radiating furnace tubes is not parallel.
Figure 10 makes up the vertical view of the layout synoptic diagram of arranging for two groups of 2/1-1 type type radiating furnace tubes of the present invention; The plane, two root entry pipe places of the first journey pipe A becomes non-vanishing angle with plane E, penetrate boiler tube the first journey pipe A bend pipe with the angled plane F of plane E in crooked; The adjacent layout of the second journey pipe B of the first journey pipe A of one group of radiating furnace tube and another group radiating furnace tube, and the return bent pipe web member of two groups of radiating furnace tubes is parallel.
Figure 11 makes up the vertical view of the layout synoptic diagram of arranging for two groups of 2/1-1 type radiating furnace tubes of the present invention; The plane, two root entry pipe places of the first journey pipe A becomes non-vanishing angle with plane E, the bend pipe of the first journey pipe A of radiating furnace tube with the angled plane F of plane E in crooked; The adjacent layout of the second journey pipe B of two groups of radiating furnace tubes, and the return bent pipe web member of two groups of radiating furnace tubes is not parallel.
Figure 12 is the diagrammatic top view of one group of 2/1-1 radiating furnace tube of the present invention; The plane, two root entry pipe places of the first journey pipe A becomes non-vanishing angle with plane E, and the first journey pipe A of first radiating furnace tube is parallel with the bend pipe projection of the second journey pipe B of the 7th radiating furnace tube; The first journey pipe A of second radiating furnace tube is parallel with the bend pipe projection of the second journey pipe B of the 6th radiating furnace tube; The first journey pipe A of the 3rd radiating furnace tube is parallel with the bend pipe projection of the second journey pipe B of the 5th radiating furnace tube; The first journey pipe A of the 4th radiating furnace tube is parallel with the bend pipe projection of the second journey pipe B of the 4th radiating furnace tube; The first journey pipe A of the 5th radiating furnace tube is parallel with the bend pipe projection of the second journey pipe B of the 3rd radiating furnace tube; The first journey pipe A of the 6th radiating furnace tube is parallel with the bend pipe projection of the second journey pipe B of second radiating furnace tube; The first journey pipe A of the 7th radiating furnace tube is parallel with the bend pipe projection of the second journey pipe B of first radiating furnace tube.
Figure 13 is the diagrammatic top view of one group of 2/1-1 radiating furnace tube of the present invention; The plane, two root entry pipe places of the first journey pipe A becomes non-vanishing angle with plane E, and the first journey pipe A of each radiating furnace tube is parallel with the bend pipe projection of the second journey pipe B.
Embodiment
Below describe and only represent the specific embodiment of the present invention,, and do not limit the invention just for further the present invention will be described.
Below in conjunction with accompanying drawing 9 ethane cracking furnace of the present invention is described:
It comprises high pressure gas bag 1, convection zone 2, radiation section 3, is arranged vertically many groups radiating furnace tube 4, burner 5, quenching boiler 6 at radiation section; Described radiation section burner hearth height 13693mm, width 4150mm, length 15276mm arranges 4 radiant section furnace tube modules.With 7 boiler tubes is one group, and the outlet of two groups of boiler tubes is concentrated and is arranged in together.Arrange 56 boiler tubes altogether, the first journey pipe bore 40-60mm wherein, the second journey pipe bore 62-72mm.The boiler tube caliber is a certain value in above-mentioned scope.The first journey pipe hypomere tube spacing is 100-130mm, and the second journey pipe hypomere tube spacing is 120-140mm, boiler tube length overall 26-28m, and segment length is the 20-30% of first Cheng Zhiguan on first journey.
Form the vertical radiating furnace tube of two journeys that each 2/1-1 type is arranged by the first journey pipe A and the second journey pipe B, between the first journey pipe and the second journey pipe, adopt return bent pipe web member 11 to connect;
The cracking material is introduced by the first journey pipe, is drawn by the second journey pipe.The first journey pipe top is two root entry pipes 7, after merging by a threeway member 8, fixedlys connected with an end of described return bent pipe web member by a bend pipe 10 again; The second journey pipe of radiating furnace tube comprises: an outlet pipe 13, fixedly connected with the other end of described return bent pipe web member by a bend pipe 12 in its lower end.The centre symmetry line of the first all journey pipe of one group of radiating furnace tube and the medullary ray of the second journey pipe constitute plane E.The bend pipe 10 of the first journey pipe is at the vertical plane inner bending perpendicular to plane E; The bend pipe 12 of the second journey pipe with the vertical plane inner bending of the angled angle of plane E, each is unequal for the plane, bend pipe place of each boiler tube two journey pipes of same group of boiler tube and plane E angle, angle is the 70-90 degree.
Every radiating furnace tube outlet pipe connects a linear quenching boiler.Parallel to each other the arranging of each boiler tube return bent pipe web member.Boiler tube positions by the constant force spring hanging frame at top and the guide pipe of bottom.The radiation section heat supply is provided jointly by base burning device and radiant wall burner, wherein bottom heat supply 65%.
And if adopt the 2-1 type boiler tube of traditional single layout, can arrange 44 boiler tubes altogether, a journey bore 40-60mm wherein, two journey bore 65-75mm.The boiler tube caliber is a certain value in above-mentioned scope.The first journey pipe tube spacing is that 90-100mm, the second journey pipe tube spacing are 120-140mm, boiler tube length overall 26-28m.
For a kind of petroleum naphtha, arrange for these two kinds different radiating furnace tubes respectively, in the operating mode that guarantees stably operable, in identical cracking severity (propylene/ethylene=0.5, weight ratio) under, the pyrolyzer that adopts traditional 2-1 to arrange can feed intake 29.2 tons/hour, yield of ethene 28.05% (weight), and the pyrolyzer that adopts 2/1-1 of the present invention to arrange can feed intake 37 tons/hour, yield of ethene 27.98% (weight).Can see and improve the output of pyrolyzer greatly by the present invention.The different operating mode contrasts of two kinds of layouts see Table 1.
Table 1 embodiment operating mode contrast unlike the prior art
1.: the radiation section pressure drop is excessive, is unfavorable for the device normal running.
2.: the device processing power is low.