CN2787662Y

CN2787662Y - Mixed diversion mechanism of urea-synthesizing tower

Info

Publication number: CN2787662Y
Application number: CNU2005200715509U
Authority: CN
Inventors: 陈然; 任大明
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-05-09
Filing date: 2005-05-09
Publication date: 2006-06-14
Anticipated expiration: 2015-05-09

Abstract

The utility model relates to a mixing and liquid leading mechanism of a urea synthesizing tower, which can resolve the problem of the low conversion rate of CO2 caused by disadvantage factors, such as flow block of tower walls, material backmixing, nonuniform gas-liquid mixing, etc. The utility model is characterized in that the elevation angle of vanes on a spiral plate is 15 DEG, and eyelets on a porous plate are distributed in a concentric circle shape. The diameters of the eyelets are inchmeal enlarged from an inner part to an outer part, and the range of the eyelet diameter is from phi 6 to phi 10. Furthermore, the spiral plates and the porous plates are crosswise, alternately and uniformly distributed at the middle and the upper parts of the inside of the urea synthesizing tower. The utility model has the advantage that because the flow defects of liquid in the tower can be overcome, the ideal plunger piston type rising state of the materials can be realized in the tower. Furthermore, the conversion rate of CO2 can be enhanced, can be kept at 69 percent generally and can reach 73 percent at most.

Description

The mixing deflector of urea synthesizer

Technical field

The utility model relates to a kind of apparatus for urea synthesis, specifically the mixing deflector of urea synthesizer.

Background technology

Urea synthesizer is the key equipment in the urea plant, NH ₃, CO ₂And the first liquid that the recycle system reclaims enters in the tower at the bottom of tower, and gas-liquid mixture flows from bottom to top, carries out building-up reactions simultaneously and part generates urea.Do not limit if do not add guiding device (column internals), tower inner fluid flow state certainly exists following defective:

1, because of tower wall effect (viscous flow of tower wall) form " protruding stream ", promptly in the middle of flow velocity fast, near more tower wall flow velocity is slow more, can not make full use of volume.

2, gas ratio liquid liter advance fast and becoming causes gas-liquid full and uniformly not mix, and contact area is few, and the time is short.

3, in the process that the gas-liquid liter advances, building-up reactions is constantly carried out, and urea content is more up big more, causes little (the about 680kg/m of tower inner fluid bottom density ³), big (the about 1100kg/m of top density ³), " top-heavy " and produce air-teturning mixed phenomenon.Being upper liquid (urea content is higher) sinks and mixes with the fluid that rises to liter advancing from periphery circlewise, goes round and begins again.

These factors obviously are unfavorable for urea synthesis reaction, make reaction away from equilibrium state.

CO ₂Transformation efficiency is the important process technical parameter of this tower operation, and it is worth every raising 1%, and middle pressure load then descends 10%, can save steam 100kg.So it is high more that the big more urea of its value generates ratio, decompose, the recirculation system load is more little, help more that device is energy-conservation taps the latent power.Therefore, novel column internals is constantly being explored, researched and developed in each scientific research, design department and manufacturing enterprise all, are intended to improve the flow state of tower inner fluid, to impel CO ₂The raising of transformation efficiency.

At present, the inner parts structure that urea synthesizer adopted that in the medium and small urea plant of China, puts into operation, nothing more than three kinds of patterns:

1, the left and right three blocks of eddy flow plates (elevation angle is 30 °) that revolve are installed in the bottom, in, top installs some blocks of porous plates (sieve plate), the eye diameter on every block of porous plate is identical, and adopts trilateral evenly to arrange, and claims porous plate internals (tower tray).

2, the left and right three blocks of eddy flow plates (elevation angle is 30 °) that revolve are installed in the bottom, in, top installs some ball caps or hump hat type porous plate, except that calotte, eye diameter is identical and adopt trilateral evenly to arrange, and claims ball cap or hump plate column internals (tower tray) on every block of porous plate.

3, the left and right three blocks of eddy flow plates (elevation angle is 30 °) that revolve are installed in the bottom, the stage casing mounting heat exchanger, and epimere is equipped with tower tray, claims isothermal built-up type column internals.

These several internals are playing some effects aspect minimizing fluid back-mixing, the reduction gas flow rate, but still unsatisfactory, and fail to overcome the tower wall effect, and gas-liquid mixed is also even inadequately, so CO ₂Transformation efficiency can only reach 62-67%, differs far away with equilibrium conversion.Wherein isothermal built-up type internals CO ₂Transformation efficiency is higher slightly, but structure is complicated, and installation difficulty is big, more inconvenient maintenance.

Summary of the invention

The purpose of this utility model is: a kind of CO is provided ₂The transformation efficiency height, simple in structure, install and to overhaul the mixing deflector of urea synthesizer easily.

The technical solution that realizes the foregoing invention purpose is as follows:

1, the mixing deflector of urea synthesizer comprises eddy flow plate, porous plate, it is characterized in that:

The blade elevation angle on A, the described eddy flow plate is 15 degree;

Eyelet on B, the described porous plate adopts the concentric(al) circles form to arrange, and eye diameter increases from inside to outside gradually, and the eye diameter scope is Φ 6-Φ 10, and the described eyelet number of turns is the 8-15 circle, and every circle eyelet number is 6-120;

C, described eddy flow plate and porous plate staggered alternate be distributed in the urea synthesizer in, top.

2, according to the mixing deflector of above-mentioned 1 described urea synthesizer, it is characterized in that: the eyelet on the described porous plate adopts the concentric(al) circles form to arrange, and eye diameter increases from inside to outside gradually, and eye diameter is Φ 6, Φ 8, Φ 10;

The every circle hole count of described Φ 6 eyelets is 6-10, and the number of turns is the 1-5 circle;

The every circle hole count of described Φ 8 eyelets is 10-60, and the number of turns is the 1-5 circle;

The every circle hole count of described Φ 10 eyelets is 30-120, and the number of turns is the 1-5 circle.

The utility model is by the improvement to eddy flow plate, perforated plate construction, in in urea synthesizer, top adopts eddy flow plate and the staggered alternate distribution equalizing structure form of porous plate, overcome tower inner fluid mobile defect, the ideal liter that makes material be embodied as " plunger " shape in tower advances state, has improved CO ₂Transformation efficiency, CO ₂Transformation efficiency generally remains on 69%, is up to 73%.

Description of drawings

Fig. 1 is the utility model structural representation,

Fig. 2 is an eddy flow plate structure synoptic diagram,

Fig. 3 is the perforated plate construction synoptic diagram.

Embodiment

Below in conjunction with accompanying drawing, the utility model is further described by embodiment.

Embodiment:

The mixing deflector of urea synthesizer comprises eddy flow plate 1, porous plate 2.

Wherein, blade 5 elevations angle on the eddy flow plate 1 are 15 degree, see Fig. 2; Eyelet 6 on the porous plate 2 adopts the concentric(al) circles form to arrange, and eye diameter increases from inside to outside gradually, and the eye diameter scope is Φ 6-Φ 10, and eye diameter is Φ 6, Φ 8, Φ 10, sees Fig. 3.

Eye diameter is that the every circle hole count of the eyelet of Φ 6 is 6-10, and the number of turns is the 1-5 circle;

The every circle hole count of the eyelet of eye diameter Φ 8 is 10-60, and the number of turns is the 1-5 circle;

The every circle hole count of the eyelet of eye diameter Φ 10 is 30-120, and the number of turns is the 1-5 circle.

End section is provided with several eddy flow plates (left and right rotating plate is alternate) equally in order to gas-liquid mixed in urea synthesizer 3, identical with original technology, epimere was provided with interlock alternate uniform eddy flow plate 1 and porous plate 2 during the innovation part was urea synthesizer 3 in, see Fig. 1, its spacing is identical with original technology with the syndeton form, simple in structure, be convenient to install and maintenance.

During operation, material (CO ₂, NH ₃,-first liquid) at the bottom of tower, enter, through the left and right eddy flow plates in several of bottoms mix the back in, the epimere liter advances, and alternately passes through porous plate 2 and eddy flow plate 1.Because porous plate 2 circulation apertures become medium and small, the limit that becomes is big, and concentric(al) circles arranges, and material is played guide functions, forces material to become " plunger " shape liter to advance.Eddy flow plate 1 not only further mixes gas-liquid, makes material even, advances to have increased impellent also for simultaneously peripheral material liter, overcoming tower wall resistance, and has given effective inhibition to gas flow rate and material back-mixing.The combined action of such two kinds of tower trays has guaranteed that then gas-liquid fully contacts in the material, and full cross section liter advances, and has promoted CO ₂Conversion and the generation of urea.The material liter enters the top and promptly discharges from outlet pipe 4, enters decomposition, recovery system after the decompression.

Claims

The blade elevation angle on A, the described eddy flow plate is 15 degree;

2, the mixing deflector of urea synthesizer according to claim 1 is characterized in that: the eyelet on the described porous plate adopts the concentric(al) circles form to arrange, and eye diameter increases from inside to outside gradually, and eye diameter is Φ 6, Φ 8, Φ 10;