CN212639970U

CN212639970U - Urea pyrolysis reactor

Info

Publication number: CN212639970U
Application number: CN202020794390.5U
Authority: CN
Inventors: 刘志新
Original assignee: TIANJIN PLOUGH ENERGY TECHNOLOGY DEVELOPMENT CO LTD
Current assignee: TIANJIN PLOUGH ENERGY TECHNOLOGY DEVELOPMENT CO LTD
Priority date: 2020-05-13
Filing date: 2020-05-13
Publication date: 2021-03-02
Anticipated expiration: 2030-05-13

Abstract

The utility model provides a urea pyrolysis reactor, include from last to down the air inlet that sets gradually, enlarge section, reactor body, shrink section, gas outlet, the upper portion of reactor body is equipped with five spray guns, five the spray gun is located same horizontal plane and all sets up five on one of them spray gun of spray gun is located the central line of reactor body, and the spray gun outside on the central line of four surplus spray gun circumference equipartitions and the inner wall of reactor body between the distance equal reactor body's the third of the internal diameter, the spray gun is connected with the urea solution pipeline, the middle part of reactor body is equipped with the equipartition ware, the lower part of reactor body is equipped with vortex generator, the outside top-down of reactor body coils in proper order and is equipped with a plurality of groups electric heating wire. The utility model has the advantages of the hydrojet is even, reaction dwell time is long, the decomposition is abundant, product gas misce bene, and the practicality is strong in actual production.

Description

Urea pyrolysis reactor

Technical Field

The utility model belongs to the technical field of the urea pyrolysis, especially, relate to a urea pyrolysis reactor.

Background

Nitrogen oxides (NOx) are one of main atmospheric pollutants, and along with the implementation of strict environmental protection standards, a flue gas denitration system becomes an indispensable device of a thermal power plantOne of the alternative catalytic Reduction reactions (SCR for short) is the first choice of the technology of the power plant denitration project due to the advantage of high denitration efficiency, and is increasingly widely applied. Reducing agent NH in SCR technology₃The sources of (A) are 3 types: liquid ammonia, ammonia water and urea, and urea is selected as a reducing agent, so that the method has the characteristics of high safety, wide sources, easiness in transportation and storage and the like, and is widely applied to the field of environmental protection.

The urea pyrolysis furnace is a main reaction device for preparing ammonia by urea pyrolysis, and structurally comprises a cylindrical furnace body, wherein a urea solution atomization device is arranged on the cylindrical furnace body; the upper stream of the cylindrical furnace body is connected with a pyrolysis air guide section, and the pyrolysis air guide section comprises a straight cylinder section for introducing pyrolysis air and a conical cylinder section connected to the straight cylinder section and the upper end of the cylindrical furnace body; the downstream of the cylindrical furnace body is provided with a reaction gas outlet. When the urea pyrolysis furnace operates, pyrolysis air is introduced from the straight cylinder section, flows through the conical cylinder section and contacts with urea fog drops, and a generated mixture (reaction gas, also called product gas) of ammonia and the pyrolysis air is discharged from the reaction gas outlet.

However, the existing pyrolysis furnace is caused by NH in product gas₃The distribution is uneven, consequently can influence going on of denitration on next step, and the pyrolysis oven generally only sets up a spray gun moreover, thereby also can lead to the poor and atomized urea liquid drop distribution of the poor and uneven urea liquid drop of the regulation nature of urea solution along with operating mode load change to influence urea and decompose.

SUMMERY OF THE UTILITY MODEL

In view of this, the present invention is directed to a urea pyrolysis reactor to overcome NH in product gas in the prior art₃Uneven distribution, poor adjustability of the urea solution along with the change of the working condition load and uneven distribution of atomized urea droplets.

In order to achieve the above purpose, the technical scheme of the utility model is realized like this:

the utility model provides a urea pyrolysis reactor, includes from last air inlet, enlarged section, reactor body, shrink section, the gas outlet that sets gradually extremely down, the upper portion of reactor body is equipped with five spray guns, five the spray gun is located same horizontal plane and all sets up, five on one of them spray gun of spray gun is located the central line of reactor body, and four remaining spray gun circumference equipartitions on the central line the spray gun outside and with the inner wall of reactor body between the distance equal the third of the internal diameter of reactor body, the spray gun is connected with the urea solution pipeline, the middle part of reactor body is equipped with the equipartition ware, the lower part of reactor body is equipped with vortex generator, the outside top-down of reactor body coils in proper order and is equipped with a plurality of electric heating wire of group.

Further, the uniform distributor comprises a uniform distribution plate, the uniform distribution plate is circular, the uniform distribution plate is fixed on the inner wall of the reactor body, and a plurality of through holes which are communicated up and down are uniformly distributed on the uniform distribution plate.

Further, the vortex generator comprises a central column and at least two helical blades of helical structures fixed on the periphery of the central column, the helical centers of the helical blades are overlapped with the axis of the central column, and the outer edges of the helical blades are in close contact with the inner wall of the reactor body.

Furthermore, the top of center post is fixed with and is no less than two erection columns, erection column circumference equipartition just extends along the radial of reactor body, and the one end that the erection column outwards is fixed in on the inner wall of reactor body.

Furthermore, three groups of electric heating wires are sequentially coiled on the outer side of the reactor body from top to bottom.

Furthermore, each group of electric heating wires is respectively connected with a temperature control system.

Furthermore, the reactor body is a cylinder which is made of heat-resistant steel and has a hollow structure with openings at the upper end and the lower end.

Compared with the prior art, the urea pyrolysis reactor has the following advantages:

(1) urea pyrolysis reactor, be equipped with five spray guns just the spray gun all sets up, the first downstream again that makes progress of atomizing urea liquid drop, has prolonged the stroke orbit of urea liquid drop, that is to say, has prolonged the dwell time of urea liquid drop in reaction unit, makes atomizing urea liquid drop take place secondary collision, forms more carefullySmall liquid drops are favorable for full reaction; the lower part of the reactor body is provided with a vortex generator containing air, ammonia gas and CO₂When the product gas of the mixed gas passes through the vortex generator, the product gas rotates clockwise/anticlockwise in the vortex generator, so that the ammonia gas is distributed in the mixed gas more uniformly, and the next denitration reaction is facilitated;

(2) urea pyrolysis reactor, be equipped with electric heating wire and temperature control system, make this internal temperature of reactor suitable through temperature control system and electric heating wire to avoid the production of accessory substance and crystallization, electric heating wire is total three groups moreover, can divide into three reaction section with the reactor body, the segmentation accuse temperature improves accuse temperature accuracy.

Drawings

The accompanying drawings, which form a part hereof, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention without undue limitation. In the drawings:

FIG. 1 is an overall structural diagram of a urea pyrolysis reactor according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a vortex generator of a urea pyrolysis reactor according to an embodiment of the present invention;

fig. 3 is a structural diagram of an equilizer of a urea pyrolysis reactor in an embodiment of the present invention.

Description of reference numerals:

1. an air inlet; 2. an amplifying section; 3. a reactor body; 4. a contraction section; 5. an air outlet; 6. a spray gun; 7. a urea solution conduit; 8. a uniform distribution plate; 9. a through hole; 10. an electric heating wire; 11. a temperature control system; 12. a central column; 13. a helical blade; 14. and (6) mounting the column.

Detailed Description

It should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

A urea pyrolysis reactor is shown in figures 1-3 and comprises an air inlet 1, an amplification section 2, a reactor body 3, a contraction section 4 and an air outlet 5 which are sequentially arranged from top to bottom, wherein the reactor body 3 is a cylinder which is made of heat-resistant steel and has openings at the upper end and the lower end and is of a hollow structure. The upper part of the reactor body 3 is provided with five spray guns 6, the spray guns 6 are connected with urea solution pipelines 7, and the spray guns 6 can atomize the urea solution into small drops with the size ranging from several micrometers to dozens of micrometers. Five spray gun 6 is located same horizontal plane and all sets up, and the atomized urea liquid drop is upwards again downstream earlier, has prolonged the stroke orbit of urea liquid drop, that is to say, has prolonged the dwell time of urea liquid drop in reaction unit, makes atomized urea liquid drop take place the secondary collision, forms more tiny liquid drop, is favorable to abundant reaction.

One lance 6 of the five lances 6 is located on the central line of the reactor body 3, and the remaining four lances 6 are circumferentially and uniformly distributed outside the lances 6 on the central line and have a distance from the inner wall of the reactor body 3 equal to one third of the inner diameter of the reactor body 3. So set up, guarantee that 6 spun atomizing urea liquid drops of spray gun evenly spray 3 insides to the reactor, be favorable to the decomposition of urea.

The middle part of reactor body 3 is equipped with the equipartition ware, the equipartition ware includes equipartition board 8, equipartition board 8 is circular, and on the equipartition board 8 was fixed in the inner wall of

reactor body

3, 8 evenly distributed of equipartition board had a plurality of through-holes 9 that link up from top to bottom. The equipartition ware sets up in the middle part of reactor body 3, rectifies the air current that reachs here for the air current distributes evenly, and the rectification is effectual.

The reactor is characterized in that a vortex generator is arranged at the lower part of the reactor body 3, the vortex generator comprises a central column 12 and at least two spiral blades 13 which are fixed on the periphery of the central column 12 and have a spiral structure, the spiral centers of the spiral blades 13 are overlapped with the axis of the central column 12, and the outer edges of the spiral blades 13 are in close contact with the inner wall of the reactor body 3. Four mounting columns 14 are fixed on the top of the central column 12, the mounting columns 14 are circumferentially and uniformly distributed and extend along the radial direction of the reactor body 3, and the outward ends of the mounting columns 14 are fixed on the inner wall of the reactor body 3. When the product gas containing the mixed gas of air, ammonia gas and CO2 passes through the vortex generator, clockwise/anticlockwise rotation occurs in the vortex generator, so that the ammonia gas is more uniformly distributed in the mixed gas, and the denitration reaction of the next step is facilitated. Of course, other types of vortex generators capable of performing the above-described functions may be used in the prior art, and will not be described herein.

For heating reactor body 3, the outside top-down of reactor body 3 coils in proper order and is equipped with three group electric heating wire 10, every group electric heating wire 10 is connected with temperature control system 11 respectively. Make the temperature in the reactor body 3 suitable through temperature control system 11 and electric heating wire 10 to avoid the production of accessory substance and crystallization, electric heating wire 10 is total three groups moreover, can be divided into three reaction sections with reactor body 3, and the segmentation accuse temperature improves accuse temperature accuracy. In specific implementation, the number of the electric heating wires 10 and the temperature control systems 11 can be increased or decreased according to needs.

The utility model discloses a working process:

high-temperature hot air with the temperature of 600 ℃ enters from the air inlet 1, 50% of urea solution enters the spray gun 6 from the urea solution pipeline 7, the spray gun 6 sprays atomized urea droplets upwards, the urea droplets move upwards and are contacted with the hot air, and the urea is decomposed to generate ammonia and CO₂Containing air, ammonia and CO₂The product gas of mist continues downstream and carries out the rectification through the equipartition ware for gas distribution is even, and at this in-process, urea decomposition process continues to go on, then, the product gas continues to get into vortex generator downwards, and the product gas takes place clockwise/anticlockwise rotation in vortex generator, makes the distribution of ammonia in mist more even, is favorable to denitration reaction on next step. In the reaction process, the temperature control system 11 controls the electric heating wire 10 in real time, and controls the temperature of the reactor body 3 to be not less than 350 ℃.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A urea pyrolysis reactor, characterized in that: include from last to down the air inlet that sets gradually, enlarge section, reactor body, shrink section, gas outlet, the upper portion of reactor body is equipped with five spray guns, five the spray gun is located on same horizontal plane and all sets up, five on one of them spray gun of spray gun is located the central line of reactor body, and remaining four spray gun circumference equipartitions on the central line the spray gun outside and with the inner wall of reactor body between the distance equal the third of the internal diameter of reactor body, the spray gun is connected with the urea solution pipeline, the middle part of reactor body is equipped with the equipartition ware, the lower part of reactor body is equipped with vortex generator, the outside top-down of reactor body coils in proper order and is equipped with a plurality of electric heating wire of group.

2. The urea pyrolysis reactor of claim 1, wherein: the uniform distributor comprises a uniform distribution plate, the uniform distribution plate is circular and is fixed on the inner wall of the reactor body, and a plurality of through holes which are communicated up and down are uniformly distributed on the uniform distribution plate.

3. The urea pyrolysis reactor of claim 1, wherein: the vortex generator comprises a central column and at least two helical blades of helical structures fixed on the periphery of the central column, the helical centers of the helical blades are overlapped with the axis of the central column, and the outer edges of the helical blades are in close contact with the inner wall of the reactor body.

4. The urea pyrolysis reactor of claim 3, wherein: the top of center post is fixed with and is no less than two erection columns, erection column circumference equipartition just follows the radial extension of reactor body, and the one end that the erection column outwards is fixed in on the inner wall of reactor body.

5. The urea pyrolysis reactor of claim 1, wherein: three groups of electric heating wires are sequentially coiled on the outer side of the reactor body from top to bottom.

6. The urea pyrolysis reactor of claim 5, wherein: each group of electric heating wires is respectively connected with a temperature control system.

7. The urea pyrolysis reactor of claim 1, wherein: the reactor body is a cylinder which is made of heat-resistant steel and has a hollow structure with openings at the upper end and the lower end.