CN103172085B - Air flow guiding method for urea pyrolytic reaction - Google Patents
Air flow guiding method for urea pyrolytic reaction Download PDFInfo
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- CN103172085B CN103172085B CN201310046726.4A CN201310046726A CN103172085B CN 103172085 B CN103172085 B CN 103172085B CN 201310046726 A CN201310046726 A CN 201310046726A CN 103172085 B CN103172085 B CN 103172085B
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Abstract
The invention relates to an air flow guiding method for urea pyrolytic reaction. The urea pyrolytic reaction is carried out in a reactor. The reactor comprises a reactor inlet, a reactor body and a reactor outlet, wherein a spray gun for providing an atomized urea solution is arranged on the reactor body, hot air in the urea pyrolytic reaction enters the reactor and is guided to form a two-dimensional flow field, the two-dimensional flow field formed by slow rotational air flow in the inner central area of the reactor, and high-speed straight air flow is formed on the peripheral area at the periphery of the inner wall of the reactor. The reaction retention time can be prolonged through the central slow rotational air flow, and the urea solution is prevented from crystallizing and adhering with the wall through the high-speed straight air flow which is formed on the peripheral part, so that the reaction efficiency is increased.
Description
Technical field
The present invention relates to urea pyrolysis reaction field, in especially a kind of urea pyrolysis reaction, guide the method for air-flow
Background technology
Oxynitride (NOx) is one of main atmospheric polluting material, along with the enforcement of strict environmental protection standard, flue gas denitrification system becomes one of requisite equipment of thermal power plant, selective catalytic reduction reaction (Selective Catalyst Reduction, be called for short SCR) to become the technology of power plant's denitration project with the advantage that its denitration efficiency is high first-selected, and obtain and apply more and more widely.In SCR technology, the source of reductive agent NH3 has 3 kinds: liquefied ammonia, ammoniacal liquor and urea, selects urea as reductive agent, has that security is high, wide material sources, is easy to the features such as transport and storage, be widely used at field of Environment Protection.
The decomposition of urea is mainly carried out in pyrolysis reactor, pyrolysis reactor is the complete empty container in an inside, warm air enters from entrance, urea provides the injector distributed completely to be injected in warm air through one to react, pyrolysis reactor, is made up of parts such as entrance, amplification section, body, contraction section, outlets.In order to increase ureaclastic reaction time, the flow velocity of hot blast in pyrolysis reactor must being reduced, therefore body upper part is provided with amplification section, for amplifying body diameter, thus reaching the object reducing warm air flow velocity.In conventional pyrolytic reactor design, adopt and amplify the requirement that this single method of body diameter reaches the pyrolytic reaction residence time, there is certain limitation, or entrance is set to Venturi tube structure, need longer stable section, comprise that entrance reduces, throat, outlet flaring, length requirement is higher, due to the space constraint by scene, this method is for the more difficult realization of the design arrangement of large-scale reactor in Practical Project, and the reaction chamber of pyrolysis installation is made up of stainless steel, the pyrolysis installation manufacturing cost of large volume is higher.
When air-flow enters reactor, there is no drainage system, the air flow method in pyrolysis reactor can be caused uneven, because urea decomposition reaction completes in a short period of time, generally only has the time in a few second, very high to the requirement in gas flowfield and temperature field, if gas flowfield and thermo parameters method inequality, urea just can not decompose completely, undecomposed urea can on tail pipe tube wall crystallization deposition, the increasing of urea crystals phenomenon can cause the increase of maintenance number of times, and serious also can impact the operation of urea pyrolysis system.
Disclose in patent documentation CN101574616A a kind of bicarbonate of ammonia ammonia pyrolysis oven, described pyrolysis body of heater lower part cloth four warm air inlet tubes, the deflection of described four warm air inlet tubes has certain spin intensity after arranging and making warm air enter pyrolysis oven, make fluid field in furnace degree of filling good, uniformity of temperature profile in pyrolysis oven.But due to bicarbonate of ammonia used be solid particulate, decompose to make described solid particulate and need fierce percussion movement, so the warm air in described pyrolysis oven needs to be designed to rotational flow, and hot air inlet is located at pyrolysis oven bottom, the swirling eddy of bottom ensures that solid particulate does not land, and urea ammonia urea used is solution, it is desirable that have the warm air of steady flow speed from top to bottom, therefore the pyrolysis installation of above-mentioned bicarbonate of ammonia is not suitable for the pyrolysis of urea.
The disclosed pyrolysis installation for urea ammonia of patent documentation CN201907975U, comprise gas inlet, inside is provided with reaction chamber and the pneumatic outlet of spray gun, described gas inlet is arranged at described reaction chamber top, described pneumatic outlet is arranged at described reaction chamber bottom, also comprise and be arranged at described reaction chamber inside and the sieve plate type flow distributor on described spray gun top, inner and be provided with the sieve plate type flow distributor being provided with multiple perforate on spray gun top at reaction chamber, make the hot gas flow entering pyrolysis installation in diffusion process, achieve the hot gas flow flow field evenly flowed downward quickly, improve the position positioned opposite of spray gun, pyrolysis installation is made to have shorter length requirement, effectively reduce the height of pyrolysis installation, but, air-flow must by entering with very multiporous orifice plate, resistance is very large, can build-up of pressure loss.
Given this present invention is proposed.
Summary of the invention
Object of the present invention is for overcoming the deficiencies in the prior art, the method of air-flow is guided in providing a kind of urea pyrolysis to react, warm air in the reaction of this method urea pyrolysis is used to enter reactor and form the air-flow that central zone is slow eddy flow after guiding, extend the residence time, sufficient reacting, the circumferential area of inside reactor periphery of inner wall is the air-flow of High-speed DC, isolation atomize urea solution and reactor wall, stops urea soln crystallization on reactor wall.
In order to realize this object, the present invention adopts following technical scheme:
The method of air-flow is guided in a kind of urea pyrolysis reaction, described urea pyrolysis reaction is carried out in reactor, described reactor comprises reactor inlet, reactor body and reactor outlet, described reactor body is arranged the spray gun that atomize urea solution is provided, in described urea pyrolysis reaction, warm air enters reactor and form two-dimensional flow field after guiding, the air-flow of described two-dimensional flow field to be inside reactor central zone be slow eddy flow, the circumferential area of inside reactor periphery of inner wall is the air-flow of High-speed DC.
The speed of the air-flow of described central zone is less than the speed of the air-flow of circumferential area.
The air-flow of described circumferential area is close to reactor wall, and the reactant of inside reactor and reactor wall are kept apart by High-speed DC.
The method comprises the following steps:
1) warm air is passed into reactor inlet;
2) central zone of described warm air is divided into multichannel air-flow by swirl-flow devices, and is guided into vortex gas-flow by swirl-flow devices; The air-flow of the circumferential area of described warm air keeps High-speed DC when entering, and forms two-dimensional flow field;
3) multi-cyclone air-flow after swirl-flow devices because inertia to form the air-flow of slow eddy flow at inside reactor, fully mix with the atomize urea solution of inside reactor, extend the residence time, the High-speed DC of circumferential area moves downward along reactor wall, atomize urea solution and reactor wall are kept apart, stops urea soln crystallization on reactor wall;
4) warm air of described slow eddy flow mixes with the atomize urea solution of inside reactor, atomize urea solution generation pyrolytic reaction.
Described 1) speed passing into warm air in is greater than 8 metre per second (m/s)s.
Described 2) in, warm air speed after swirl-flow devices reduces 80-90%.Part in reactor inlet place and/or reactor body more than spray gun forms two-dimensional flow field.
Described 3) in, the air-flow of the High-speed DC of circumferential area extrudes the air-flow of slow eddy flow, the inner circulating reflux that restriction Swirl causes.
Described swirl-flow devices to comprise on the cylinder of a closed at both ends and column side face at least two and rotates in the same direction and the eddy current curved surface bucket of equally distributed spirane structure, the helical centre of described eddy current curved surface bucket is arranged along column axis direction, described cylinder guides warm air to enter, stop multiple inlet mouth mutually to disturb, described eddy current curved surface bucket guides warm air to form slow eddy flow along blade shape.
Described swirl-flow devices is positioned at reactor inlet and/or reactor body, forms an annular section apart from reactor wall certain distance, and the speed when warm air maintenance that this annular section passes through enters and direction, form High-speed DC.
After adopting technical solutions according to the invention, bring following beneficial effect:
1, arrange after swirl-flow devices guides hot gas flow to enter reactor and form eddy flow, to extend the residence time.
2, swirl-flow devices adopts multiple eddy current curved surface bucket, uniform stream.
3, arrange the cylinder of closed at both ends in the middle of swirl-flow devices, intermediate cylinder plays the effect of guiding gas air inlet, and gas, around cylinder rotating inlet, with not having cylinder to compare, can avoid the mutual interference between multiple inlet mouth.
4, arranging ring-type open base area around swirl-flow devices guides the gas entered to form direct current high velocity at reactor wall place, prevents drop crystallization from gluing wall.
5, efficiency improves, and reaction efficiency improves more than 14%.
Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in further detail.
Accompanying drawing explanation
Fig. 1: urea pyrolysis reactor structure iron of the present invention
Fig. 2: the structure drawing of device forming two-dimensional flow field in urea pyrolysis reactor of the present invention
Fig. 3: swirl-flow devices structure iron of the present invention
Wherein: 1, reactor inlet, 2, amplify section, 3, spray gun, 4, reactor body, 5, contraction section, 6, reactor outlet, 7, cylinder, 8, eddy current curved surface bucket, 9, cylindrical surface, 10, ring-type open base area, 11 devices forming two-dimensional flow fields, 12, swirl-flow devices.
Concrete real mode
The method of air-flow is guided in a kind of urea pyrolysis reaction of the present invention, described urea pyrolysis reaction is carried out in reactor, described reactor comprises reactor inlet, reactor body and reactor outlet, described reactor body is arranged the spray gun that atomize urea solution is provided, in described urea pyrolysis reaction, warm air enters reactor and form two-dimensional flow field after guiding, the air-flow of described two-dimensional flow field to be inside reactor central zone be slow eddy flow, the circumferential area of inside reactor periphery of inner wall is the air-flow of High-speed DC.
The speed of the air-flow of described central zone is less than the speed of the air-flow of circumferential area.The air-flow of described circumferential area is close to reactor wall, and the reactant of inside reactor and reactor wall are kept apart by High-speed DC.
The method comprises the following steps:
1) warm air is passed into reactor inlet;
2) central zone of described warm air is divided into multichannel air-flow by swirl-flow devices, and is guided into vortex gas-flow by swirl-flow devices; The air-flow of the circumferential area of described warm air keeps High-speed DC when entering, and forms two-dimensional flow field;
3) multi-cyclone air-flow after swirl-flow devices because inertia to form the air-flow of slow eddy flow at inside reactor, fully mix with the atomize urea solution of inside reactor, extend the residence time, the High-speed DC of circumferential area moves downward along reactor wall, atomize urea solution and reactor wall are kept apart, stops urea soln crystallization on reactor wall;
4) warm air of described slow eddy flow mixes with the atomize urea solution of inside reactor, atomize urea solution generation pyrolytic reaction.
The air-flow of described slow eddy flow is by the reaction zone of inside reactor, and the air-flow of this slow eddy flow extends air-flow in the residence time of inside reactor, can extend the time of reaction, allow sufficient reacting carry out; The air-flow of described High-speed DC is positioned at inside reactor next-door neighbour reactor wall, and reactor wall and inside reactor reaction zone are kept apart by the air-flow of this High-speed DC, prevent the crystallization of internal solution contact reactor inwall from sticking on reactor wall.
Described 1) speed passing into warm air in is greater than 8 metre per second (m/s)s, generally reaches tens of metre per second (m/s).
Described 2) in, warm air speed after swirl-flow devices reduces 80-90%.Part in reactor inlet place and/or reactor body more than spray gun forms two-dimensional flow field.
Described 3) in, the air-flow of the High-speed DC of circumferential area extrudes the air-flow of slow eddy flow, the inner circulating reflux that restriction Swirl causes.
Described swirl-flow devices to comprise on the cylinder of a closed at both ends and column side face at least two and rotates in the same direction and the eddy current curved surface bucket of equally distributed spirane structure, the helical centre of described eddy current curved surface bucket is arranged along column axis direction, described cylinder guides warm air to enter, stop multiple inlet mouth mutually to disturb, described eddy current curved surface bucket guides warm air to form slow eddy flow along blade shape.
Described swirl-flow devices is positioned at reactor inlet and/or reactor body, forms an annular section apart from reactor wall certain distance, and the speed when warm air maintenance that this annular section passes through enters and direction, form High-speed DC.
Described swirl-flow devices comprises the eddy current curved surface bucket of at least two spirane structures on a cylinder and column side face, the helical centre of described eddy current curved surface bucket is arranged along column axis direction, described cylinder closed at both ends, multiple eddy current curved surface bucket rotates in the same direction at column side face and is uniformly distributed.Described eddy current curved surface bucket is the spirane structure at least comprising 0.5 pitch, and the number of described eddy current curved surface bucket is 4 to 10, preferably 6.One cylindrical surface is set between described swirl-flow devices and ring-type open base area, this cylindrical surface isolation High-speed DC air-flow and slow vortex gas-flow.
The device of described formation two-dimensional flow field is positioned at reactor inlet place, and the device 11 of described formation two-dimensional flow field is with the inwall assembly connection of reactor inlet 1 or be welded to connect.
The device of described formation two-dimensional flow field also can be positioned at reactor body, and the device 11 of described formation two-dimensional flow field is with the inwall assembly connection of reactor body or be welded to connect.When the device of formation two-dimensional flow field is positioned at reactor body, the above position of spray gun is positioned at.
Amplification section can also be provided with between described reactor inlet and reactor body, contraction section can also be provided with between described reactor body and reactor outlet, amplifying section is that the design of amplifying gradually keeps flow field not producing turbulent flow through amplifying section, when suitable angle design can be guaranteed to amplify, flow field keeps stable, amplify ingress diameter and the reactor inlet place equal diameters of section, amplify the exit of section and the equal diameters of reactor body, the diameter of the ingress of contraction section and the equal diameters of reactor body, the diameter in the exit of contraction section and the equal diameters of reactor exit.
The device of described formation two-dimensional flow field also can be positioned at and amplify section, and the device 11 of described formation two-dimensional flow field is with the inwall assembly connection of amplification section or be welded to connect.
The air input of described reactor inlet is Q, and the width of described eddy current curved surface bucket is W, Q/W
2=N, wherein N is certain value, and N value is relevant with the distribution form in flow field; The width of described eddy current curved surface bucket and the ratio of height are between 1:2 to 2:1; The ratio of the diameter of described swirl-flow devices and the reactor inlet at device place or the diameter of reactor body that form two-dimensional flow field is between 1:2 to 4:5.
In described urea pyrolysis reaction, warm air enters reactor inlet with the speed being greater than ten metre per second (m/s)s, after the swirl-flow devices of centre, air-flow forms eddy flow, speed reduces 80-90%, form the air-flow of slow eddy flow, after the ring-type open base area of surrounding, gas velocity is constant, form the air-flow of High-speed DC, air-flow reaction zone in reactor of described slow eddy flow extends the residence time, promote that sufficient reacting carries out, the air-flow of described High-speed DC, along reactor wall flow at high speed, prevent the crystallization of internal solution contact reactor inwall from sticking on reactor wall.
Warm air is heated to about about 600 DEG C by external heat source, pass through reactor inlet, reactor body is entered after amplifying section, during by reactor inlet, owing to being provided with the device forming two-dimensional flow field in reactor inlet, by the guiding function of the swirl-flow devices of middle portion, enter the warm air of swirl-flow devices, by the guiding function of eddy current curved surface bucket, middle part forms slow vortex gas-flow, by the guiding function of peripheral annular open base area, around position forms High-speed DC air-flow, namely in described urea pyrolysis reaction, warm air enters the air-flow being formed slow eddy flow in reactor by the device guiding warm air of formation two-dimensional flow field at inside reactor middle portion, the air-flow of High-speed DC is formed at inside reactor peripheral part.
Thus after warm air enters and amplify section and reactor body, inertia time owing to entering, making warm air be formed middle is slow eddy flow, it is around the flow field of High-speed DC, spray gun is connected to two-way entrance: a road is the urea soln configured, one tunnel is atomizing air, urea soln by lance ejection in reactor body, react in the warm air of the urea soln be atomized in reactor body, because warm air forms centre for slow eddy flow, it is around the flow field of High-speed DC, middle slow vortex gas-flow can extend the time of stop, thus react fully, High-speed DC air-flow around can form high velocity at reactor body inwall, prevent urea soln crystallization from gluing wall, all right extruding center eddy flow district, the scope in the inner circulating reflux district that effective restriction Swirl causes.
What the warm air before comparing was vertical passes through pyrolysis reactor, owing to forming eddy flow, when reactor body length is constant, add the residence time of mixed airflow in reactor body, thus be conducive to the abundant decomposition of urea, when the residence time is constant, the height of reactor body can be reduced, thus reduction manufacturing cost, form High-speed DC air-flow around and can isolate internal solution and reactor wall, avoid internal solution contact reactor inwall to cause crystallization, affect reaction efficiency.
Under the high temperature conditions, urea generation decomposition reaction, its chemical reaction is as follows:
CO(NH
2)
2→NH
3+HNCO
HNCO+H
2O→NH
3+CO
2
Resultant of reaction and warm air form mixed gas and discharge through reactor outlet, then enter SCR reactor.
Embodiment one
As shown in Figure 3, swirl-flow devices 12 of the present invention comprises the eddy current curved surface bucket 8 of 6 spirane structures on a cylinder 7 and cylinder 7 side, the helical centre of described eddy current curved surface bucket 8 is arranged along cylinder 7 axis direction, the height of 6 described eddy current curved surface buckets 8 is consistent with the height of cylinder 7, and upper and lower ends is concordant respectively.
Described cylinder 7 closed at both ends, middle cylinder 7 plays the effect of guiding gas air inlet, gas is around cylinder 7 rotating inlet, compare with there is no cylinder 7, the mutual interference between multiple inlet mouth can be avoided, multiple eddy current curved surface bucket 8 rotates in the same direction in cylinder 7 side and is uniformly distributed, and is conducive to being uniformly distributed of air-flow, and described eddy current curved surface bucket 8 is the spirane structure at least comprising 0.5 pitch.
Also can be regarded as and one end of a strip thin plate is fixed, the other end reverses along the medullary ray perpendicular to inboardend of strip thin plate the spirane structure that tabular is turned round in gradual change that certain angle obtains clockwise or counterclockwise gradually, described certain angle by entrance 1 flow velocity, height determine with diameter, the present embodiment preferably turns round turnback, is the spirane structure of 0.5 pitch; After the medullary ray that plate is turned round in the gradual change of three above-mentioned identical spirane structures overlaps, position of center line arranges the cylinder of a closed at both ends, three gradual changes are turned round plate and are divided into two eddy current curved surface buckets respectively by cylinder, namely formed cylinder 7 side on be uniformly distributed the identical eddy current curved surface bucket 8 of 6 sense of rotation.
Embodiment two
As shown in Figure 2, the device 11 of formation two-dimensional flow field of the present invention is preferably arranged in reactor inlet 1, and the device 11 of described formation two-dimensional flow field comprises middle portion and guides air-flow to form the slow down swirl-flow devices 12 of flow velocity and peripheral portion of eddy flow to guide the swiftly flowing ring-type open base area 10 of air-flow.
Cylindrical surface 9 is set between swirl-flow devices 12 and ring-type open base area 10, cylindrical surface 9 isolated DC high velocity air and slow vortex gas-flow, avoids the mutual interference between air-flow.
The region surrounded in the middle of cylindrical surface 9 is guide air-flow to form eddy flow to slow down the swirl-flow devices 12 of flow velocity, and the region between cylindrical surface 9 and reactor inlet 1 inwall is for guiding the swiftly flowing ring-type open base area 10 of air-flow.
Device 11 upper end forming two-dimensional flow field is concordant with reactor inlet upper end, or device 11 upper end of formation two-dimensional flow field is lower than reactor inlet upper end, is conducive to the distribution of air-flow like this.
Form device 11 and the reactor inlet assembly connection of two-dimensional flow field, or be welded to connect with reactor inlet inwall.
Through forming the device 11 of two-dimensional flow field after warm air enters reactor inlet 1, when middle swirl-flow devices 12, gas passes through from the helical channel between eddy current curved surface bucket 8, the air-flow of slow eddy flow in the middle of being formed, the air-flow of High-speed DC around the guiding of peripheral cyclic open base area is formed, the air-flow extended residence time in the reactor of middle slow eddy flow can be made like this, react fully, around the spray reaction zone of inside and reactor body 4 isolate and prevent drop crystallization from gluing wall by the air-flow of High-speed DC, all right extruding center eddy flow district, the scope in the inner circulating reflux district that effective restriction Swirl causes.
Embodiment three
In the amplification section 2 that the device 11 of formation two-dimensional flow field of the present invention can also be arranged on reactor (not shown in FIG.), the device 11 of described formation two-dimensional flow field comprises middle portion and guides air-flow to form the slow down swirl-flow devices 12 of flow velocity and peripheral portion of eddy flow to guide the swiftly flowing ring-type open base area 10 of air-flow.
Cylindrical surface 9 is set between swirl-flow devices 12 and ring-type open base area 10, cylindrical surface 9 isolated DC high velocity air and slow vortex gas-flow, avoids the mutual interference between air-flow.
The region surrounded in the middle of cylindrical surface 9 is guide air-flow to form eddy flow to slow down the swirl-flow devices 12 of flow velocity, and cylindrical surface 9 and the region of amplifying between section 2 inwall are for guiding the swiftly flowing ring-type open base area 10 of air-flow.
Device 11 upper end forming two-dimensional flow field is concordant with amplification section 2 upper end, or device 11 upper end of formation two-dimensional flow field is lower than amplification section 2 upper end, is arranged on to amplify in section 2 can allow warm air after ingress is evenly distributed at the two-dimentional eddy flow of formation.
Form the device 11 of two-dimensional flow field and amplification section 2 assembly connection, or be welded to connect with amplification section 2 inwall.
Warm air enters the device 11 of the formation two-dimensional flow field amplified in section 2 after entering reactor inlet 1, when middle swirl-flow devices 12, gas passes through from the helical channel between eddy current curved surface bucket 8, the air-flow of slow eddy flow in the middle of being formed, the air-flow of High-speed DC around the guiding of peripheral cyclic open base area is formed, the air-flow extended residence time in the reactor of middle slow eddy flow can be made like this, react fully, around the spray reaction zone of inside and reactor body 4 isolate and prevent drop crystallization from gluing wall by the air-flow of High-speed DC, all right extruding center eddy flow district, the scope in the inner circulating reflux district that effective restriction Swirl causes.
Embodiment four
The device 11 of formation two-dimensional flow field of the present invention can also be arranged in reactor body 4 (not shown in FIG.), but be arranged on position more than spray gun in reactor body 4, the device 11 of described formation two-dimensional flow field comprises middle portion and guides air-flow to form the slow down swirl-flow devices 12 of flow velocity and peripheral portion of eddy flow to guide the swiftly flowing ring-type open base area 10 of air-flow.
Cylindrical surface 9 is set between swirl-flow devices 12 and ring-type open base area 10, cylindrical surface 9 isolated DC high velocity air and slow vortex gas-flow, avoids the mutual interference between air-flow.
The region surrounded in the middle of cylindrical surface 9 is guide air-flow to form eddy flow to slow down the swirl-flow devices 12 of flow velocity, and the region between cylindrical surface 9 and reactor body 4 inwall is for guiding the swiftly flowing ring-type open base area 10 of air-flow.
Device 11 upper end forming two-dimensional flow field is concordant with reactor body 4 upper end, or form device 11 upper end of two-dimensional flow field lower than reactor body 4 upper end, be arranged in reactor body 4 and warm air can be allowed after ingress is evenly distributed to form two-dimentional eddy flow through amplifying after section 2 guides, avoid amplifying section 2 to the impact of two-dimensional flow field.
Form device 11 and reactor body 4 assembly connection of two-dimensional flow field, or be welded to connect with reactor body 4 inwall.
Warm air enters after entering reactor inlet 1 and amplifies section 2 guides flow area to amass to be amplified into the formation two-dimensional flow field of reactor body 4 device 11 through amplifying section 2, when middle swirl-flow devices 12, gas passes through from the helical channel between eddy current curved surface bucket 8, the air-flow of slow eddy flow in the middle of being formed, the air-flow of High-speed DC around the guiding of peripheral cyclic open base area is formed, the air-flow extended residence time in the reactor of middle slow eddy flow can be made like this, react fully, around the spray reaction zone of inside and reactor body 4 isolate and prevent drop crystallization from gluing wall by the air-flow of High-speed DC, all right extruding center eddy flow district, the scope in the inner circulating reflux district that effective restriction Swirl causes.
Embodiment five
The device 11 of formation two-dimensional flow field of the present invention can also be arranged on reactor inlet 1 simultaneously, two or three structures interior (not shown in FIG.) of amplifying in section 2 and reactor body 4, but be arranged in reactor body 4 position making to be arranged on more than spray gun, the device 11 of described formation two-dimensional flow field comprises middle portion and guides air-flow to form the slow down swirl-flow devices 12 of flow velocity and peripheral portion of eddy flow to guide the swiftly flowing ring-type open base area 10 of air-flow.
Cylindrical surface 9 is set between swirl-flow devices 12 and ring-type open base area 10, cylindrical surface 9 isolated DC high velocity air and slow vortex gas-flow, avoids the mutual interference between air-flow.
The region surrounded in the middle of cylindrical surface 9 is guide air-flow to form eddy flow to slow down the swirl-flow devices 12 of flow velocity, and cylindrical surface 9 and reactor inlet 1 or the region of amplifying between section 2 or reactor body 4 inwall are for guiding the swiftly flowing ring-type open base area 10 of air-flow.
The device 11 forming two-dimensional flow field is set in multiple structure simultaneously, better can guides the formation two-dimensional flow field of air-flow.
The device 11 forming two-dimensional flow field is with reactor inlet 1 or amplify section 2 or reactor body 4 assembly connection, or with reactor inlet 1 or amplify section 2 or reactor body 4 inwall is welded to connect.
Through forming the device 11 of two-dimensional flow field after warm air enters reactor inlet 1, when middle swirl-flow devices 12, gas passes through from the helical channel between eddy current curved surface bucket 8, the air-flow of slow eddy flow in the middle of being formed, the air-flow of High-speed DC around the guiding of peripheral cyclic open base area is formed, the air-flow extended residence time in the reactor of middle slow eddy flow can be made like this, react fully, around the spray reaction zone of inside and reactor body 4 isolate and prevent drop crystallization from gluing wall by the air-flow of High-speed DC, all right extruding center eddy flow district, the scope in the inner circulating reflux district that effective restriction Swirl causes.
The foregoing is only the preferred embodiment of the present invention, it should be pointed out that for the ordinary skill in the art, without departing from the principles of the present invention, can also make various deformation and improvement, this also should be considered as protection scope of the present invention.
Claims (10)
1. in a urea pyrolysis reaction, guide the method for air-flow, described urea pyrolysis reaction is carried out in reactor, described reactor comprises reactor inlet, reactor body and reactor outlet, described reactor body is arranged the spray gun that atomize urea solution is provided, it is characterized in that: in the reaction of described urea pyrolysis, warm air enters reactor and forming reactions device interior central area is the air-flow of slow eddy flow after guiding, and the circumferential area of inside reactor periphery of inner wall is the flow field of the air-flow of High-speed DC.
2. guide the method for air-flow in urea pyrolysis reaction according to claim 1, it is characterized in that: the speed of the air-flow of described central zone is less than the speed of the air-flow of circumferential area.
3. guide the method for air-flow in urea pyrolysis reaction according to claim 2, it is characterized in that: the air-flow of described circumferential area is close to reactor wall, the reactant of inside reactor and reactor wall are kept apart by High-speed DC.
4. guide the method for air-flow in urea pyrolysis reaction according to claim 3, it is characterized in that: the method comprises the following steps:
1) warm air is passed into reactor inlet;
2) central zone of described warm air is divided into multichannel air-flow by swirl-flow devices, and is guided into vortex gas-flow by swirl-flow devices; The air-flow of the circumferential area of described warm air keeps High-speed DC when entering, and forming reactions device interior central area is the air-flow of slow eddy flow, and the circumferential area of inside reactor periphery of inner wall is the flow field of the air-flow of High-speed DC;
3) multi-cyclone air-flow after swirl-flow devices because inertia to form the air-flow of slow eddy flow at inside reactor, fully mix with the atomize urea solution of inside reactor, extend the residence time, the High-speed DC of circumferential area moves downward along reactor wall, atomize urea solution and reactor wall are kept apart, stops urea soln crystallization on reactor wall;
4) warm air of described slow eddy flow mixes with the atomize urea solution of inside reactor, atomize urea solution generation pyrolytic reaction.
5. guide the method for air-flow in urea pyrolysis reaction according to claim 4, it is characterized in that: the speed passing into warm air described 1) is greater than 8 metre per second (m/s)s.
6. guide the method for air-flow in urea pyrolysis reaction according to claim 4, it is characterized in that: described 2), warm air speed after swirl-flow devices reduces 80-90%.
7. guide the method for air-flow in urea pyrolysis reaction according to claim 4, it is characterized in that: described 3), the air-flow of the High-speed DC of circumferential area extrudes the air-flow of slow eddy flow, the inner circulating reflux that restriction Swirl causes.
8. in urea pyrolysis reaction according to claim 4, guide the method for air-flow, it is characterized in that: the part forming reactions device interior central area described 2) in reactor inlet place and/or reactor body more than spray gun is the air-flow of slow eddy flow, and the circumferential area of inside reactor periphery of inner wall is the flow field of the air-flow of High-speed DC.
9. in urea pyrolysis reaction according to claim 4, guide the method for air-flow, it is characterized in that: described swirl-flow devices to comprise on the cylinder of a closed at both ends and column side face at least two and rotates in the same direction and the eddy current curved surface bucket of equally distributed spirane structure, the helical centre of described eddy current curved surface bucket is arranged along column axis direction, described cylinder guides warm air to enter, stop multiple inlet mouth mutually to disturb, described eddy current curved surface bucket guides warm air to form slow eddy flow along blade shape.
10. in urea pyrolysis reaction according to claim 9, guide the method for air-flow, it is characterized in that: described swirl-flow devices is positioned at reactor inlet and/or reactor body, an annular section is formed apart from reactor wall certain distance, speed when the warm air maintenance that this annular section passes through enters and direction, form High-speed DC.
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|---|---|---|---|
| CN201310046726.4A CN103172085B (en) | 2013-02-06 | 2013-02-06 | Air flow guiding method for urea pyrolytic reaction |
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| CN106082271B (en) * | 2016-06-01 | 2018-07-03 | 福建龙净环保股份有限公司 | Suitable for the urea back-mixing pyrolysis installation and method for pyrolysis of SCR denitration system |
| CN109529622B (en) * | 2019-01-16 | 2023-11-14 | 北京工大环能科技有限公司 | Flue gas tail denitration system for multiple gas internal combustion engines |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008134641A1 (en) * | 2007-04-27 | 2008-11-06 | Babcock Power Inc. | Conversion of urea to reactants for nox reduction |
| CN201907975U (en) * | 2010-11-25 | 2011-07-27 | 北京洛卡环保技术有限公司 | Pyrolysis device for utilizing urea for ammonia preparation |
| CN102614758A (en) * | 2012-04-20 | 2012-08-01 | 湖南安普诺环保科技有限公司 | Urea-solution-based SCR (selective catalytic reduction) flue gas denitration process and device |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008134641A1 (en) * | 2007-04-27 | 2008-11-06 | Babcock Power Inc. | Conversion of urea to reactants for nox reduction |
| CN201907975U (en) * | 2010-11-25 | 2011-07-27 | 北京洛卡环保技术有限公司 | Pyrolysis device for utilizing urea for ammonia preparation |
| CN102614758A (en) * | 2012-04-20 | 2012-08-01 | 湖南安普诺环保科技有限公司 | Urea-solution-based SCR (selective catalytic reduction) flue gas denitration process and device |
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Address after: 100097 Beijing Haidian District Zizhuyuan Road No. 120 Patentee after: DATANG ENVIRONMENT INDUSTRY GROUP CO., LTD. Patentee after: China Datang Technologies & Engineering Co., Ltd. Address before: 100097 Beijing Haidian District Zizhuyuan Road No. 120 Patentee before: Environment Technology Co., Ltd. of China Datang Corporation Patentee before: China Datang Technologies & Engineering Co., Ltd. |