1. The utility model provides a sled dress horizontal urea pyrolysis oven which characterized in that includes: the device comprises an inlet section, a gradually expanding section, a main body section, a contracting section, an outlet section, a variable-diameter porous plate, a spray gun and a water-floating guide plate, wherein the inlet section, the gradually expanding section, the main body section, the contracting section and the outlet section are transversely communicated; the inlet section, the main body section and the outlet section are cylindrical, the diameter of the main body section is larger than that of the inlet section and that of the outlet section, and the gradually expanding section and the contracting section are both in the shape of a hollow circular truncated cone; one end of the inlet section is provided with an air inlet; the small bottom surface of the gradually expanding section is connected with the other end of the inlet section, and the large bottom surface is connected with one end of the main body section; the large bottom surface of the contraction section is connected with the other end of the main body section, and the small bottom surface is connected with one end of the outlet section; the other end of the outlet section is an air outlet; the variable-diameter porous plate is a circular plate which is vertically arranged, the edge of the variable-diameter porous plate is connected to the inner wall, close to the divergent section, of the main body section, a plurality of rows of round holes with different apertures are distributed on the variable-diameter porous plate, and the apertures of the round holes are sequentially increased from top to bottom; the spray gun is positioned at one side of the relative variable-diameter porous plate close to the contraction section, and the spray nozzle is positioned on the axis of the main body section and faces the air outlet; the water-floating type guide plate is fixed on one side, far away from the variable-diameter porous plate, of the relative spray gun and is of a transverse wedge-shaped structure, the end, close to the spray gun, of the guide plate is a head, the end, far away from the spray gun, of the guide plate is a tail, and the tail is higher than the head to form a slope.

2. The skid-mounted horizontal urea pyrolysis furnace as claimed in claim 1, wherein the spray gun is arranged at a distance of 300-500mm from the junction of the main section and the divergent section.

3. The skid-mounted horizontal urea pyrolysis furnace as claimed in claim 2, wherein the distance between the variable-diameter perforated plate and the spray gun is 150 mm and 250 mm.

4. The skid-mounted horizontal urea pyrolysis furnace as claimed in claim 2, wherein the head of the guide plate is 500mm away from the spray gun 300.

5. The skid-mounted horizontal urea pyrolysis furnace according to claim 1, wherein the rows of the circular holes of the variable-diameter porous plate are arranged in horizontal rows and vertical rows, and the diameter of the circular holes of each row is increased in an arithmetic progression from top to bottom with a tolerance range of 2-4 mm.

6. A skid-mounted horizontal urea pyrolysis furnace as claimed in claim 5, wherein the variable diameter perforated plate has 69 circular holes in 9 rows and 9 columns, and the center distance of each row of circular holes is 40 mm.

7. A skid-mounted horizontal urea pyrolysis furnace as claimed in claim 6, wherein the diameter of the circular holes in the row at the bottom of the variable-diameter porous plate is 36 mm.

8. The skid-mounted horizontal urea pyrolysis furnace as claimed in claim 1, wherein the water-floating type guide plate is connected with the bottom of the inner wall of the main section, and the length of the water-floating type guide plate is 600-800 mm.

9. The skid-mounted horizontal urea pyrolysis furnace of claim 1, wherein the height of the tail part of the water-floating deflector relative to the head part is 40-60 mm.

Background

The denitration reducing agents adopted in the existing SCR and SNCR denitration processes are generally three, namely liquid ammonia, ammonia water and urea, the liquid ammonia has the highest denitration efficiency, the raw materials are wide in source and low in price, but the liquid ammonia has the characteristics of flammability and explosiveness and has strict requirements on transportation, storage and use for hazardous chemicals; the efficiency of ammonia water as a denitration agent is lower than that of liquid ammonia, the transportation, storage and management are all lower than that of the liquid ammonia, meanwhile, the safety problem also exists, and the consumption and transportation cost are overhigh; however, urea is a granular agricultural fertilizer, is safe and harmless, and is preferably used as a reducing agent in denitration scenes of large, medium and small cities and suburbs thereof.

The existing urea pyrolysis device is mainly applied to large-scale application fields such as power plants, waste incineration plants and the like, but cannot be fully paid attention to small-scale application (such as small-sized boilers, diesel vehicles and the like). The existing large-scale urea pyrolysis furnace has larger size and large occupied space, and is not beneficial to small-scale application.

Disclosure of Invention

The invention aims to provide a skid-mounted horizontal urea pyrolysis furnace which is horizontal, small in size and convenient to apply so as to solve the problem of small-flow urea pyrolysis.

In order to achieve the purpose, the invention provides the following technical scheme:

a skid-mounted horizontal urea pyrolysis furnace comprises: the device comprises an inlet section, a gradually expanding section, a main body section, a contracting section, an outlet section, a variable-diameter porous plate, a spray gun and a water-floating guide plate, wherein the inlet section, the gradually expanding section, the main body section, the contracting section and the outlet section are transversely communicated; the inlet section, the main body section and the outlet section are cylindrical, the diameter of the main body section is larger than that of the inlet section and that of the outlet section, and the gradually expanding section and the contracting section are both in the shape of a hollow circular truncated cone; one end of the inlet section is provided with an air inlet; the small bottom surface of the gradually expanding section is connected with the other end of the inlet section, and the large bottom surface is connected with one end of the main body section; the large bottom surface of the contraction section is connected with the other end of the main body section, and the small bottom surface is connected with one end of the outlet section; the other end of the outlet section is an air outlet; the variable-diameter porous plate is a circular plate which is vertically arranged, the edge of the variable-diameter porous plate is connected to the inner wall, close to the divergent section, of the main body section, a plurality of rows of round holes with different apertures are distributed on the variable-diameter porous plate, and the apertures of the round holes are sequentially increased from top to bottom; the spray gun is positioned at one side of the relative variable-diameter porous plate close to the contraction section, and the spray nozzle is positioned on the axis of the main body section and faces the air outlet; the water-floating type guide plate is fixed on one side, far away from the variable-diameter porous plate, of the relative spray gun and is of a transverse wedge-shaped structure, the end, close to the spray gun, of the guide plate is a head, the end, far away from the spray gun, of the guide plate is a tail, and the tail is higher than the head to form a slope.

Further, the arrangement position of the spray gun is 500mm away from the connection part of the main body section and the divergent section, the interval between the variable-diameter porous plate and the spray gun is 150 mm and 250mm, and the head part of the guide plate is 500mm away from the spray gun.

Furthermore, a plurality of rows of round holes of the variable-diameter porous plate are arranged in horizontal rows and vertical rows, the aperture of each row of round holes is increased in an arithmetic progression from top to bottom, and the tolerance range is 2-4 mm.

Further, the variable diameter porous plate has 69 circular holes in 9 rows and 9 columns, and the center distance of each row of circular holes is 40 mm.

Further, the diameter of the circular holes in the row at the bottom of the variable-diameter porous plate (the diameter is largest) is 36 mm.

Further, the water float type guide plate is connected with the bottom of the inner wall of the main body section, and the length of the water float type guide plate is 600-800 mm.

Further, the height of the tail part of the water floating type guide plate relative to the head part is 40-60 mm.

The skid-mounted horizontal urea pyrolysis furnace has the beneficial effects that: hot air enters from an air inlet of the pyrolysis furnace and enters the inside of the pyrolysis furnace through the variable-diameter porous plate, and the variable-diameter porous plate is provided with 9 rows of round holes from bottom to top, the diameters of the round holes are in an arithmetic progression, and the tolerance range is 2-4 mm. When hot air passes through the porous plate with the variable diameter, the gas flow rate is changed, so that the gas flow rate of the lower half part of the main body section is high, and the gas flow rate of the upper half part of the main body section is low. The influence of gravity on the urea solution can be effectively relieved, and the risk that liquid particles sprayed by the spray gun are stained with the wall can be avoided. In order to prevent the gas flow rate in the second half section of the main body section from being insufficient, a water floating type guide plate with the height of 40-60mm and the length of 600-800mm is arranged at the position 500mm away from the spray gun. After the hot air passes through the guide plate, the air rises along the guide plate at a certain angle (4-6 degrees) and has a certain shrinkage effect on the lower half part of the urea solution, so that the urea solution is prevented from being stained on the wall. According to the skid-mounted horizontal urea pyrolysis furnace, the urea solution particles are uniformly distributed in the pyrolysis furnace through the matching combination of the variable-diameter porous plate and the water-floating guide plate, so that on one hand, hot air forms high-speed airflow at the lower half part of the main body section, urea liquid drops are not easy to adhere to the furnace wall after being sprayed into the furnace body, and crystallization is avoided. On the other hand, the guide plate plays a role in lifting the airflow at the lower half part of the main body section, so that the tail end of urea solution particles can be contracted, and the urea solution is uniformly distributed in the main body section as a whole. In general, the invention effectively solves the problem that the urea solution is adhered to the furnace wall to be crystallized due to the influence of gravity in the urea pyrolysis process.

Drawings

In order to more clearly illustrate the embodiments and technical solutions of the present invention, three drawings are provided to explain the principles thereof, and the drawings are briefly described below.

The drawings in the present invention are only schematic, and the structures, sizes, and the like drawn in the drawings are only used for explaining the contents in accordance with the specification, and do not constitute an unlimited part of the present invention, so that any modification of the structures, changes of the proportional relationship, and adjustments of the sizes, all fall within the protection scope of the present invention under the similar effects and the achieved purpose of the present invention.

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

FIG. 2 is an enlarged view of a portion of a variable diameter perforated plate in the pyrolysis furnace shown in FIG. 1;

fig. 3 is a detailed view of a water-floating baffle in the pyrolysis furnace shown in fig. 1.

Description of reference numerals:

1-an inlet section; 2-a divergent section; 3-variable diameter porous plate; 4-a spray gun; 5-a water-floating type guide plate; 6-a main body section; 7-contraction section, 8-outlet section.

Detailed Description

The embodiments of the invention are described below by way of specific implementation examples, for a clear understanding of the arrangement of the invention and its advantages to a person having reference to the description. The following examples are only some examples of the present invention, and not all examples of the present invention are included in the scope of the present invention, and modifications, changes in the ratio and adjustments of the size of other structures based on the examples are included in the scope of the present invention.

Referring to fig. 1, 2 and 3, fig. 1 is a schematic structural diagram of an embodiment of a urea pyrolysis furnace provided by the present invention; FIG. 2 is a schematic view of a variable diameter perforated plate of the pyrolysis furnace shown in FIG. 1; fig. 3 is a schematic view of a deflector of the pyrolysis furnace shown in fig. 1.

In one embodiment, the urea pyrolysis furnace provided by the invention comprises an inlet section 1, a divergent section device 2, a variable-diameter porous plate 3, a spray gun 4, a main body section 5, a water-floating type guide plate 6, a contraction section 7 and an outlet section 8.

Specifically, the air inlet section 1 is cylindrical, the diameter is 100mm, and the length is 300 mm; the divergent section 2 is in a hollow round table shape, the diameter of the small bottom surface is 100mm, the diameter of the large bottom surface is 400mm, and the height between the two bottom surfaces is 260 mm; the main body section 6 is cylindrical, the diameter is 400mm, and the length is 3000 mm; the contraction section 7 is in a circular truncated cone shape, the diameter of a large bottom surface is 400mm, the diameter of a small bottom surface is 100mm, and the height between the two bottom surfaces is 260 mm; the outlet section 8 is cylindrical and has a length of 300 mm. The diameter-variable porous plate 3 comprises 9 rows of round holes, the diameter of the round hole in the first row is the smallest (2mm), the diameter of the round hole in the ninth row is the largest (36mm), and the diameter of the round hole in each row is 4mm smaller than that in the previous row. The number of the round holes in the first row and the ninth row is 5, the number of the round holes in the second row and the eighth row is 7, and the number of the round holes in the third row to the seventh row is 9. The variable diameter perforated plate is positioned 200mm to the left of the lance 4. The lance 4 is located 350mm to the right of the interface of the main body section 6 and the divergent section 2. The length of the water-floating type guide plate 5 is 700mm, the height is 50mm, and the water-floating type guide plate is positioned at the 350mm position on the right side of the spray gun 4.

In a specific embodiment, the pyrolysis furnace is used for a 29MW gas boiler SCR denitration urea pyrolysis furnace in a heat supply plant, 1 spray gun is uniformly distributed around the urea pyrolysis furnace, the spray gun extends into the urea pyrolysis furnace by 200mm, and the diameter of a spray gun pipe is 16 mm. The amount of spray liquid sprayed by the spray gun was 3kg/h (0.00083kg/s), and atomization was carried outThe air amount is 15Nm³And h, the maximum particle diameter Dmax of the atomized liquid drop is 125 um, the minimum particle diameter Dmin is 20um, the average particle diameter D32 is 50um, and the average speed of the liquid drop is 5.051 m/s. Further, the atomization angle was set to 20 degrees.

The working process of the invention is as follows: high-temperature air at 650 ℃ enters from the air inlet 1, passes through the variable-diameter porous plate 3, a large part of hot air enters the lower half part of the main body section 6, a small part of hot air enters the upper half part of the main body section 6, the hot air forms a velocity gradient from bottom to top, and the condition that urea solution particles adhere to the furnace wall due to the influence of gravity is relieved to a certain extent. The water floating type guide plate 5 is arranged, so that the tail end of urea solution particles can be contracted, and the wall sticking is avoided. The temperature sprayed by the spray gun 4 arranged in the main section 6 is 20 ℃, the 50% urea liquid drops are contacted with hot air, and after full contact reaction, pyrolysis gas is discharged from an outlet.

In the working process, the inlet hot air of the pyrolysis furnace passes through the water float type guide plate 5, the hot air enters the furnace body in an obvious velocity gradient, the flow guiding effect of the hot air is very good, and the velocity gradient can be kept from the furnace top to the furnace bottom. After the urea liquid drops with the speed of the lower half part of the main body section 6 is obviously higher than that of the upper half part of the main body section, the urea liquid drops do not stick to the wall, and the urea liquid drops do not crystallize on the furnace wall.

The above-mentioned embodiment is only a specific implementation example of the present invention, and there is no limitation to the present invention, and modifications of other structures, changes of proportion relation and adjustments of size based on the present embodiment are all within the protection scope of the present invention under the similar effects and achieved objects of the present invention.