阅读说明：本技术 一种尿素热解炉 (Urea pyrolysis furnace ) 是由 周欣 采有林 姜岸 于 2020-04-22 设计创作，主要内容包括：本发明公开一种尿素热解炉,包括炉体、炉顶盖、进口烟道和雾化器。其中,所述炉体竖直设置,炉体内部的空腔形成竖直的主烟道,且所述炉体的顶端面开设有烟气入口,所述炉体的底端面开设有烟气出口；所述炉顶盖安装于所述炉体的顶部、并遮挡所述烟气入口,所述炉顶盖与所述炉体的顶端面之间形成旋流气腔；所述进口烟道沿切线方向与所述旋流气腔相连通,所述雾化器安装于所述炉体的侧壁,氨气溶液通过所述雾化器喷入所述炉体的主烟道内。其解决了热解炉由于烟气波动引起的物料贴壁或沉积的技术问题。(The invention discloses a urea pyrolysis furnace which comprises a furnace body, a furnace top cover, an inlet flue and an atomizer. The furnace body is vertically arranged, a cavity inside the furnace body forms a vertical main flue, a smoke inlet is formed in the top end face of the furnace body, and a smoke outlet is formed in the bottom end face of the furnace body; the furnace top cover is arranged at the top of the furnace body and shields the flue gas inlet, and a cyclone gas cavity is formed between the furnace top cover and the top end surface of the furnace body; the inlet flue is communicated with the cyclone air cavity along the tangential direction, the atomizer is arranged on the side wall of the furnace body, and ammonia solution is sprayed into the main flue of the furnace body through the atomizer. The technical problem of material adherence or deposition caused by flue gas fluctuation of the pyrolysis furnace is solved.)

1. A urea pyrolysis furnace, comprising:

the furnace body (101) is vertically arranged, a vertical main flue is formed by a cavity of the furnace body (101), a flue gas inlet is formed in the top end face of the furnace body (101), and a flue gas outlet is formed in the bottom end face of the furnace body (101);

the furnace top cover (102) is arranged at the top of the furnace body (101) and shields the flue gas inlet, and a cyclone gas cavity is formed between the furnace top cover (102) and the top end surface of the furnace body (101);

the inlet flue (107), the inlet flue (107) is communicated with the swirling air cavity along the tangential direction;

atomizer (105), atomizer (105) install in the lateral wall of furnace body (101), ammonia solution passes through atomizer (105) spout into in the flue stack of furnace body (101).

2. The urea pyrolysis furnace of claim 1, further comprising:

the cyclone generator (104), the cyclone generator (104) install in the top of furnace body (101) face, and be located the cyclone air cavity, the inlet end of cyclone generator (104) with the cyclone air cavity is linked together, and the end of giving vent to anger with the flue gas entry is linked together.

3. The urea pyrolysis furnace according to claim 2, wherein the number of the flue gas inlets is plural, and each flue gas inlet is circumferentially opened on the top end surface of the furnace body (101); the number of the swirl generators (104) is multiple, and the air outlet end of each swirl generator (104) is communicated with each smoke inlet in a one-to-one correspondence manner.

4. The urea pyrolysis furnace of claim 2, wherein the swirl generator (104) comprises a draft flue and a swirl generating chamber, the draft flue being tangential to the swirl generating chamber.

5. The semi-dry desulfurization apparatus according to claim 4, wherein the ratio of the inlet height to the inlet width of the draft flue is 1:2, the ratio of the diameter of the swirling flow generating chamber to the inlet width of the draft flue is (2-0.4):1, and the ratio of the height of the swirling flow generating chamber to the inlet height of the draft flue is (3-5): 1.

6. The urea pyrolysis furnace of claim 1, wherein the number of the atomizers (105) is multiple, and each atomizer (105) is circumferentially and uniformly distributed on the side wall of the furnace body (101).

7. The urea pyrolysis furnace of claim 1, further comprising a hearth flue (103), wherein a smoke inlet end of the hearth flue (103) is communicated with a smoke outlet of the furnace body (101).

8. The urea pyrolysis furnace of claim 7, further comprising an outlet flue (106), wherein a smoke inlet end of the outlet flue (106) is in communication with a smoke outlet end of the sole flue (103).

9. The urea pyrolysis furnace of claim 8, wherein the hearth flue (103) is a tapered flue, a large end of the tapered flue forms a smoke inlet end of the hearth flue (103), and a small end of the tapered flue forms a smoke outlet end of the hearth flue (103).

10. A urea pyrolysis furnace according to any one of claims 1 to 9, characterized in that the furnace body (101) is a cylindrical tower body having a diameter to height ratio of 1 (4-5).

Technical Field

The invention relates to the technical field of flue gas denitration, in particular to a urea pyrolysis furnace.

Background

With the complete completion of the ultralow emission of the flue gas of the thermal power plant, the ultralow emission project of the flue gas adopting the SCR denitration technology, such as steel sintering, glass, coking, industrial furnaces and the like, is completely developed. In the denitration process, the pyrolysis furnace for urea decomposition needs to be pyrolyzed by a stable heat source, so that the fluctuation of the flow direction, the temperature, the load and the like of the flue gas can seriously affect the urea decomposition effect.

Disclosure of Invention

Therefore, the invention provides a urea pyrolysis furnace, which is expected to at least partially solve the technical problem of material adherence or deposition caused by flue gas fluctuation of the pyrolysis furnace.

In order to achieve the above object, the embodiments of the present invention provide the following technical solutions:

a urea pyrolysis furnace comprising:

the furnace body is vertically arranged, a vertical main flue is formed by a cavity of the furnace body, a flue gas inlet is formed in the top end face of the furnace body, and a flue gas outlet is formed in the bottom end face of the furnace body;

the furnace top cover is arranged at the top of the furnace body and shields the flue gas inlet, and a cyclone gas cavity is formed between the furnace top cover and the top end surface of the furnace body;

the inlet flue is communicated with the rotational flow air cavity along the tangential direction;

the atomizer, the atomizer install in the lateral wall of furnace body, ammonia solution passes through the atomizer spouts into in the flue of furnace body.

Further, still include:

and the swirl generator is arranged on the top end surface of the furnace body and is positioned in the swirl air cavity, the air inlet end of the swirl generator is communicated with the swirl air cavity, and the air outlet end of the swirl generator is communicated with the flue gas inlet.

Furthermore, the number of the flue gas inlets is multiple, and each flue gas inlet is circumferentially formed in the top end face of the furnace body; the swirl generators are multiple, and the air outlet end of each swirl generator is communicated with each flue gas inlet in a one-to-one correspondence manner.

Further, the swirl generator comprises a drainage flue and a swirl generation cavity, and the drainage flue is tangent to the swirl generation cavity.

Furthermore, the ratio of the inlet height of the flow guide flue to the inlet width is 1:2, the ratio of the diameter of the rotational flow generating cavity to the inlet width of the flow guide flue is (2-0.4):1, and the ratio of the height of the rotational flow generating cavity to the inlet height of the flow guide flue is (3-5): 1.

Furthermore, the atomizer is a plurality of, each atomizer circumference evenly distributed in the lateral wall of furnace body.

Further, the furnace comprises a furnace bottom flue, wherein the smoke inlet end of the furnace bottom flue is communicated with the smoke outlet of the furnace body.

Further, the smoke-discharging device also comprises an outlet flue, and the smoke-discharging end of the outlet flue is communicated with the smoke-discharging end of the furnace bottom flue.

Further, the stove bottom flue is a conical flue, the large end of the conical flue forms the smoke inlet end of the stove bottom flue, and the small end of the conical flue forms the smoke outlet end of the stove bottom flue.

Further, the furnace body is a cylindrical tower body, and the ratio of the diameter to the height of the cylindrical tower body is 1 (4-5).

The urea pyrolysis furnace provided by the invention comprises a furnace body, a furnace top cover, an inlet flue and an atomizer. The furnace body is vertically arranged, a cavity inside the furnace body forms a vertical main flue, a smoke inlet is formed in the top end face of the furnace body, and a smoke outlet is formed in the bottom end face of the furnace body; the furnace top cover is arranged at the top of the furnace body and shields the flue gas inlet, and a cyclone gas cavity is formed between the furnace top cover and the top end surface of the furnace body; the inlet flue is communicated with the cyclone air cavity along the tangential direction, the atomizer is arranged on the side wall of the furnace body, and ammonia solution is sprayed into the main flue of the furnace body through the atomizer. Therefore, the flue gas enters the furnace body after swirling flow through the tangentially arranged inlet flue and the swirling flow air cavity communicated with the inlet flue, the flue gas can still flow against the wall to form heat protection on the furnace wall under the condition that the flow rate and the temperature of the flue gas entering the furnace fluctuate, and the material leaves the furnace wall to swirl inwards under the action of air flow, so that the material is prevented from adhering to the wall; meanwhile, the urea solution is atomized into fine liquid drops by the atomizer and then sprayed into the rotating airflow, and the urea pyrolysis is completed in the process that the solution is continuously evaporated by hot flue gas, so that the heat exchange and the full heat utilization of the solution and the flue gas are enhanced, the complete decomposition and non-deposition of materials are ensured, and the technical problem of material adherence or deposition caused by flue gas fluctuation of a pyrolysis furnace is solved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be apparent that the drawings in the following description are merely exemplary, and that other embodiments can be derived from the drawings provided by those of ordinary skill in the art without inventive effort.

The structures, ratios, sizes, and the like shown in the present specification are only used for matching with the contents disclosed in the specification, so as to be understood and read by those skilled in the art, and are not used to limit the conditions that the present invention can be implemented, so that the present invention has no technical significance, and any structural modifications, changes in the ratio relationship, or adjustments of the sizes, without affecting the effects and the achievable by the present invention, should still fall within the range that the technical contents disclosed in the present invention can cover.

FIG. 1 is a schematic structural view of one embodiment of a pyrolysis furnace provided in the present invention;

FIG. 2 is a schematic view of the pyrolysis furnace of FIG. 1 with the furnace roof removed;

fig. 3 is a schematic view of a swirl generator in the pyrolysis furnace shown in fig. 1.

Description of reference numerals:

101-furnace body 102-furnace top cover 103-furnace bottom flue 104-swirl generator 105-atomizer

106-outlet flue 107-inlet flue

Detailed Description

The present invention is described in terms of particular embodiments, other advantages and features of the invention will become apparent to those skilled in the art from the following disclosure, and it is to be understood that the described embodiments are merely exemplary of the invention and that it is not intended to limit the invention to the particular embodiments disclosed. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-2, fig. 1 is a schematic structural diagram of a pyrolysis furnace according to an embodiment of the present invention; FIG. 2 is a schematic view of the pyrolysis furnace shown in FIG. 1 with the furnace roof removed.

In one embodiment, the urea pyrolysis furnace provided by the invention comprises a furnace body 101, a furnace top cover 102, an inlet flue 107 and an atomizer 105, wherein the furnace top cover 102 and the inlet flue 107 can be of an integrally formed structure, that is, the two are integrated into the same part. The furnace body 101 is vertically arranged, a vertical main flue is formed by a cavity of the furnace body 101, a flue gas inlet is formed in the top end face of the furnace body 101, and a flue gas outlet is formed in the bottom end face of the furnace body 101; the furnace body 101 is the main structure of the pyrolysis furnace, and a cavity defined by a barrel-shaped side wall, a top end surface and a bottom end surface is a place for reaction, and in the reaction process, flue gas and urea materials enter the cavity and are uniformly mixed in the cavity. The furnace top cover 102 is installed on the top of the furnace body 101 and shields the flue gas inlet, a cyclone gas cavity is formed between the furnace top cover 102 and the top end face of the furnace body 101, the inlet flue 107 is communicated with the cyclone gas cavity along the tangential direction, flue gas enters the cyclone gas cavity tangentially before entering the furnace body 101, and firstly forms cyclone in the cyclone gas cavity and enters the furnace body 101 in the form of gas cyclone so as to avoid adherence or precipitation. The atomizer 105 is installed in the lateral wall of furnace body 101, and ammonia solution passes through the atomizer 105 spouts into in the flue stack of furnace body 101, ammonia solution enters into furnace body 101 after atomizing into tiny particle through atomizer 105 to the flue gas intensive mixing with the whirl form.

Specifically, the furnace body 101 is a cylindrical tower body, the diameter-height ratio of the cylindrical tower body is 1 (4-5), and the pyrolysis furnace adopting the ratio of the diameter to the height is thin and tall, so that the reaction effect is ensured, and meanwhile, the occupied area is remarkably saved.

In order to improve the smoke guiding effect, the pyrolysis furnace further comprises a furnace bottom flue 103 and an outlet flue 106, the smoke inlet end of the furnace bottom flue 103 is communicated with the smoke outlet of the furnace body 101, and the smoke inlet end of the outlet flue 106 is communicated with the smoke outlet end of the furnace bottom flue 103. The furnace bottom flue 103 is a conical flue, the large end of the conical flue forms the smoke inlet end of the furnace bottom flue 103, the small end of the conical flue forms the smoke outlet end of the furnace bottom flue 103, and the taper of the furnace bottom flue 103 is 45-55 degrees.

Thus, through the tangentially arranged inlet flue 107 and the cyclone air cavity communicated with the inlet flue 107, the flue gas enters the furnace body 101 after cyclone, under the condition that the flow rate and the temperature of the flue gas entering the furnace fluctuate, the flue gas can still flow against the wall to form heat protection on the furnace wall, and the material leaves the furnace wall to swirl inwards under the action of the air flow, so that the material is ensured not to adhere to the wall; meanwhile, the urea solution is atomized into fine liquid drops by the atomizer 105 and then sprayed into the rotating airflow, and the urea pyrolysis is completed in the process that the solution is continuously evaporated by hot flue gas, so that the heat exchange and the full heat utilization of the solution and the flue gas are enhanced, the complete decomposition and non-deposition of materials are ensured, and the technical problem of material adherence or deposition caused by the fluctuation of the flue gas in the pyrolysis furnace is solved.

In the above specific embodiment, in order to improve the swirling effect of the flue gas and further avoid the adhesion or deposition of the material, the pyrolysis furnace further includes a swirl generator 104, as shown in fig. 3, the swirl generator 104 is installed on the top end surface of the furnace body 101 and is located in the swirl air cavity, the air inlet end of the swirl generator 104 is communicated with the swirl air cavity, and the air outlet end is communicated with the flue gas inlet.

Specifically, the swirl generator 104 comprises a drainage flue and a swirl generation cavity, the drainage flue is tangent to the swirl generation cavity, swirl flue gas formed after the first-stage swirl treatment of the swirl air cavity of the inlet flue 107 enters the swirl generator 104 to carry out secondary swirl, and then enters the furnace body 101 after the secondary swirl, so that the swirl effect is improved.

The ratio of the inlet height of the flow guide flue to the inlet width is 1:2, the ratio of the diameter of the rotational flow generating cavity to the inlet width of the flow guide flue is (2-0.4):1, and the ratio of the height of the rotational flow generating cavity to the inlet height of the flow guide flue is (3-5): 1. That is, as shown in FIG. 3, the inlet of the flue gas equipartition swirl generator 104 is flat and horizontal, the inlet flue gas flow rate is 15-20m/s, the ratio of the inlet height CH to the inlet width CW is 1:2, the ratio of the diameter CF to the inlet width CW is (2-0.4):1, and the ratio of the generator height CB to the inlet height CH is: (3-5):1.

In the actual use process, in order to further improve the swirling effect, a plurality of flue gas inlets are provided, and each flue gas inlet is circumferentially arranged on the top end surface of the furnace body 101; the number of the swirl generators 104 is plural, and the air outlet end of each swirl generator 104 is communicated with each flue gas inlet in a one-to-one correspondence manner. Specifically, each of the swirl generators 104 is arranged in a circular ring, and the number of the arrangement is 3 to 5. In the working process, high-temperature flue gas tangentially enters the cyclone air cavity through the inlet flue 107, and after rotating airflow is generated in the cyclone air cavity, the high-temperature flue gas is uniformly distributed by the plurality of groups of cyclone generators 104. The flue gas tangentially enters the swirl generator 104 again to generate a plurality of small swirl flue gases which flow downwards to enter the furnace body 101. The small swirling flue gas generated by the plurality of sets of swirling generators 104 is converged into a large swirling flow according to the gas swirling convergence principle. Of these flows, the main flow rotates at the center of the furnace body 101, and a small portion of the flow rotates while adhering to the wall surface of the furnace body 101.

The number of the atomizers 105 is plural, and the atomizers 105 are circumferentially and uniformly distributed on the side wall of the furnace body 101. The atomizer 105 is specifically a two-fluid atomizer 105, each two-fluid atomizer 105 is installed in the range of 0.8-1.2m below the upper end face of the furnace body 101, and the atomized particle size of liquid droplets is controlled to be 15-30 um.

In the working process, high-temperature flue gas tangentially enters the cyclone air cavity through the inlet flue 107, and after rotating airflow is generated in the cyclone air cavity, the high-temperature flue gas is uniformly distributed by the plurality of groups of cyclone generators 104. The flue gas tangentially enters the swirl generator 104 again to generate a plurality of small swirl flue gases which flow downwards to enter the furnace body 101. The small swirling flue gas generated by the plurality of sets of swirling generators 104 is converged into a large swirling flow according to the gas swirling convergence principle. Of these flows, the main flow rotates at the center of the furnace body 101, and a small portion of the flow rotates while adhering to the wall surface of the furnace body 101. The atomizer 105 atomizes the urea solution into fine droplets and sprays the fine droplets into the rotating airflow, and urea pyrolysis is completed in the process that the solution is continuously evaporated by hot flue gas. The generated ammonia and water vapor flow downward with the rotating gas flow in the furnace body 101 and are finally tightened by the conical structure of the bottom flue 103 and flow out of the pyrolysis furnace under the guidance of the outlet flue 106. In addition, the flue gas flow field in the furnace body 101 is not influenced by the trend of the inlet flue of the pyrolysis furnace, the flue gas flow field in the furnace body 101 is in a turbulent flow state, liquid drops and the flue gas exchange fully, the retention time can reach more than 30 seconds, the flue gas in the pyrolysis furnace is in a strong rotating airflow, and dust does not accumulate at the bottom of the pyrolysis furnace and does not wet the wall.

In the following, a 30MW subcritical generator set SCR denitration urea pyrolysis furnace is taken as an example, and the process parameters of the pyrolysis furnace provided by the invention are briefly described to prove the technical effects.

When the pyrolysis furnace is applied to a 30MW subcritical generator set SCR denitration urea pyrolysis furnace, 150kg/hr of ammonia is needed for a single boiler, 4060Nm3/hr primary air (328 ℃/10kPa) is adopted to be heated to 600 ℃ through an electric heater and enters the urea pyrolysis furnace, 265kg/hr of urea solution with the mass concentration of 40-50% is consumed by the single boiler and is sprayed into the urea pyrolysis furnace through 8 double-fluid atomizers, the diameter of the furnace body is 1.8 × m, 5 groups of flue gas uniformly distributed vortex generators are arranged, the height of an inlet of the generator is 140mm, the width of the inlet of the generator is 300mm, the diameter of a cylinder of the generator is 220mm, and the height of the cylinder is 500 mm.

It is noted that, in this document, relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.