CN108905761B - Device and method for preventing urea dissolving tank from crystallizing - Google Patents
Device and method for preventing urea dissolving tank from crystallizing Download PDFInfo
- Publication number
- CN108905761B CN108905761B CN201810918256.9A CN201810918256A CN108905761B CN 108905761 B CN108905761 B CN 108905761B CN 201810918256 A CN201810918256 A CN 201810918256A CN 108905761 B CN108905761 B CN 108905761B
- Authority
- CN
- China
- Prior art keywords
- dissolving tank
- urea
- water
- micro
- spray
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000004202 carbamide Substances 0.000 title claims abstract description 128
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 title claims abstract description 125
- 238000000034 method Methods 0.000 title claims abstract description 17
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 130
- 238000005507 spraying Methods 0.000 claims abstract description 37
- 238000011010 flushing procedure Methods 0.000 claims abstract description 35
- 238000002425 crystallisation Methods 0.000 claims abstract description 33
- 230000008025 crystallization Effects 0.000 claims abstract description 33
- 239000013078 crystal Substances 0.000 claims abstract description 9
- 239000011148 porous material Substances 0.000 claims abstract description 4
- 239000007921 spray Substances 0.000 claims description 91
- 238000003756 stirring Methods 0.000 claims description 33
- 239000002245 particle Substances 0.000 claims description 6
- 239000007864 aqueous solution Substances 0.000 claims description 4
- 238000007599 discharging Methods 0.000 claims description 4
- 238000002360 preparation method Methods 0.000 claims description 4
- 230000008569 process Effects 0.000 claims description 4
- 238000004891 communication Methods 0.000 claims description 3
- 238000006460 hydrolysis reaction Methods 0.000 abstract description 12
- 230000007062 hydrolysis Effects 0.000 abstract description 10
- 230000000694 effects Effects 0.000 abstract description 9
- 239000012535 impurity Substances 0.000 abstract description 5
- 230000008021 deposition Effects 0.000 abstract description 4
- 238000004140 cleaning Methods 0.000 abstract description 3
- 239000000126 substance Substances 0.000 abstract description 3
- 230000000903 blocking effect Effects 0.000 abstract 1
- 230000002401 inhibitory effect Effects 0.000 abstract 1
- 238000005406 washing Methods 0.000 abstract 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 6
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 6
- 238000004090 dissolution Methods 0.000 description 6
- 230000009471 action Effects 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 3
- 239000003546 flue gas Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 230000000630 rising effect Effects 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 239000003344 environmental pollutant Substances 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 231100000719 pollutant Toxicity 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 239000004677 Nylon Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000012533 medium component Substances 0.000 description 1
- 239000003595 mist Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 230000002028 premature Effects 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- WTHDKMILWLGDKL-UHFFFAOYSA-N urea;hydrate Chemical compound O.NC(N)=O WTHDKMILWLGDKL-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F21/00—Dissolving
- B01F21/10—Dissolving using driven stirrers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
- B01F23/70—Pre-treatment of the materials to be mixed
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
- B01F27/80—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis
- B01F27/90—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis with paddles or arms
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
- B01F35/71—Feed mechanisms
- B01F35/717—Feed mechanisms characterised by the means for feeding the components to the mixer
- B01F35/7179—Feed mechanisms characterised by the means for feeding the components to the mixer using sprayers, nozzles or jets
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F2101/00—Mixing characterised by the nature of the mixed materials or by the application field
- B01F2101/2204—Mixing chemical components in generals in order to improve chemical treatment or reactions, independently from the specific application
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Treating Waste Gases (AREA)
Abstract
The invention relates to a device and a method for preventing crystallization of a urea dissolving tank, wherein the device comprises a urea crusher arranged outside the urea dissolving tank, a stirrer arranged in the urea dissolving tank, and a desalted water flushing and spraying system connected with the urea crusher and the stirrer; the method comprises the following steps of 1, closing a sluice valve of a dissolving tank after feeding the urea dissolving tank; step 2, inhibiting entrainment of the urea dissolving tank, and avoiding the blocking of an open pore connecting channel of the urea dissolving tank by crystallization; and 3, timely washing the crystal hardening and urea crystallization. The formed urea crystals can be effectively avoided and removed, so that the normal operation of the urea dissolving tank is ensured; the subsequent hydrolysis reaction unit is ensured to be smoothly carried out, impurities are removed and added into a hydrolysis system, and the deposition blockage of massive substances is reduced from the source; the phenomenon of the death of the crystallization plate of the charging hole is effectively avoided, the cleaning effect is obvious, the economy and the reliability are realized, and the application and the popularization prospect are wide.
Description
Technical Field
The invention relates to the technical field of removal of nitrogen oxide pollutants in flue gas, in particular to a device and a method for preventing crystallization of a urea dissolving tank.
Background
The emission of the coal-fired power plant in the production process is largeNitrogen Oxides (NO) in amounts x ). The national environmental protection department 2011 issues 'emission Standard of atmospheric pollutants for thermal Power plant' prescribing that all new thermal power units NO are required x The discharge amount reaches 100mg/m 3 The new set NO is proposed by the Committee for emission reduction, upgrading and modification of coal-electricity energy conservation and the like (2014-2020) x The emission limit reaches 50mg/m 3 . The core of controlling the emission of nitrogen oxides in coal-fired power plants is a flue gas denitration technology, and urea hydrolysis is one of the most popular denitration methods at present because of safety and reliability.
At present, as the main medium components in the urea hydrolysis ammonia production system are urea, water, ammonia gas, carbon dioxide and the like, crystallization hardening is easy to occur, so that partial conveying units are blocked or even dead, a hydrolysis reactor is taken as a node, the hydrolysis reactor usually operates under the operating conditions of 160 ℃ and 0.5MPa, and the outlet is gas with the temperature of more than 160 ℃, so that crystallization can be avoided only by providing heat preservation measures as far as possible. However, in order to avoid premature decomposition of the aqueous urea solution, which is caused by excessive temperatures, the temperature of the dissolution conveyor unit before the hydrolysis reactor is usually maintained at 40-50 ℃, so that the crystallization hardening of the urea dissolution tank is more evident, as is also demonstrated by on-site operation. Crystallization starts from the bucket elevator, and the sluice valve connected with the top of the dissolution tank of the bucket elevator is hardened and dead, so that the bucket elevator is in an open state for a long time, the crystallization corrosion of the whole channel of the bucket elevator is accelerated, and finally, the whole bucket elevator can only be replaced. Therefore, how to solve the crystallization hardening of the dissolving tank caused by urea dissolution and achieve the aim of flue gas denitration while ensuring the normal operation of the hydrolysis reactor is the main aim of the invention.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides the device and the method for preventing the urea dissolving tank from crystallizing, which have the advantages of low investment cost, convenient transformation, obvious effect, suitability for long-term running urea dissolving, great labor saving, and guarantee of the normal running of a dissolving system, and finally the normal running of the whole urea hydrolysis system, and have wide application prospects in the urea hydrolysis ammonia production system of the denitration project of the coal-fired power plant.
The invention is realized by the following technical scheme:
the device for preventing the urea dissolving tank from crystallizing comprises a urea crusher arranged outside the urea dissolving tank, a stirrer arranged in the urea dissolving tank, and a demineralized water flushing and spraying system connected with the urea crusher and the stirrer;
the discharging hole of the urea crusher is communicated with the feeding hole of the urea dissolving tank, a dissolving tank gate valve is arranged at the communicating position, and a feeding filter screen is arranged between the discharging hole of the urea crusher and the dissolving tank gate valve;
the demineralized water flushing and spraying system comprises a micro-spray rod, a demineralized water main pipe, a demineralized water flushing pipe and a demineralized water spraying pipe; the micro-spray rod is fixedly arranged on a stirring shaft of the stirring machine extending into the urea dissolving tank, and a plurality of water spray holes are formed in the micro-spray rod, wherein the axes of the stirring shaft are communicated with the desalted water spray pipe; the water inlet end of the demineralized water main pipe is connected with external demineralized water, and the water outlet end of the demineralized water main pipe is connected with the water inlet ends of the demineralized water flushing pipe and the demineralized water spraying pipe respectively; the water outlet end of the desalted water flushing pipe is arranged above the feeding filter screen; the water outlet end of the desalted water spray pipe is communicated with the micro spray rod.
Preferably, the micro-spray bars are arranged in a round bar shape, and two micro-spray bars are symmetrically arranged on the stirring shaft; the free end of the micro-spray rod is 8 cm to 12cm away from the tank body of the urea dissolving tank, and the included angle between the free end and the stirring shaft is 75 degrees to 85 degrees.
Preferably, the water spraying Kong Caiyong is a flat hole or an inclined hole, and a plurality of water spraying holes are uniformly arranged at the bottom of the micro-spray rod along the micro-spray rod.
Preferably, the water spray holes are sequentially arranged at the bottom of the micro spray rod in a W shape, every two water spray holes are in a group, and the interval between the water spray holes in the group is smaller than the interval between the adjacent water spray holes in the group; the diameter ratio of the aperture of the water spray hole to the diameter of the micro spray rod is 0.02-0.04.
Preferably, a filter is arranged at the communication part of the desalted water spray pipe and the micro spray rod.
Preferably, the urea dissolving tank is arranged below the ground, a discharge hole is arranged at the bottom of the urea dissolving tank, and an exhaust port is arranged above the urea dissolving tank.
A method for preventing crystallization of urea dissolving tank, adopting any one of the above devices, comprising,
step 1, adding desalted water into a urea dissolving tank through a desalted water flushing pipe, adding crushed and impurity-removed urea particles into the urea dissolving tank, and closing a gate valve of the dissolving tank after the addition is completed;
step 2, in the stirring process of urea aqueous solution preparation, desalted water is sent into a micro-spray rod through a desalted water spray pipe at the stirring axis of a stirrer and sprayed through a plurality of water spray holes, entrainment caused by stirring and temperature rise in a urea dissolving tank is inhibited, and the open pore connecting channel of the urea dissolving tank is prevented from being blocked by crystallization;
and 3, hardening crystals at a gate valve of the dissolving tank and timely flushing urea crystals deposited on the micro-spray rod by utilizing desalted water fed through a desalted water flushing pipe.
Further, in the step 2, the working pressure of the micro spray rod is 0.05Mpa-0.1Mpa.
Further, the demineralized water in the demineralized water flushing pipe enters the urea dissolving tank through the feeding filter screen by spraying.
Compared with the prior art, the invention has the following beneficial technical effects:
the invention takes the urea dissolving tank actually operated by a power plant as a research object, adopts a demineralized water flushing and spraying system comprising a micro-spray boom, a demineralized water main pipe, a demineralized water flushing pipe and a demineralized water spraying pipe, and simultaneously adopts a filtering mode that a dissolving tank gate valve is arranged at the communication position of a feed inlet of the urea dissolving tank, and a feed filter screen is arranged between a feed outlet and the dissolving tank gate valve, so that a special flushing, spraying and filtering structure is formed, and formed urea crystals can be effectively avoided and removed, thereby ensuring the normal operation of the urea dissolving tank; the micro-spray rod is communicated with the desalted water spray pipe through the axis of the stirring shaft, can rotate along with the rotation of the stirring shaft, so that the action and defoaming effects of the micro-spray rod are ensured, the feeding filter screen can screen out feeding impurities, the subsequent hydrolysis reaction unit is ensured to be smoothly carried out, the impurities are removed, the impurities are added into the hydrolysis system, and the deposition blockage of massive substances is reduced from the source; the gate valve of the dissolving tank can enable the gas with temperature in the urea dissolving tank to flow back to the charging port, so that the phenomenon of crystallization plate death of the charging port is effectively avoided, the cleaning effect is obvious, the economy and the reliability are realized, and the wide application and popularization prospects are realized.
Furthermore, the bottom of the micro spray rod is provided with water spray holes which are in flat holes or inclined holes in a W shape in sequence, entrainment caused by stirring and temperature rise can be effectively inhibited, solute is prevented from being carried out by rising of water vapor, and the problem of urea crystallization plate death of an opening connecting channel of a urea dissolving tank is solved; in order to avoid the mutual cross collision of the fog drops sprayed by the two groups of water spray holes, thereby changing the spraying route of the water spray mist and influencing the action effect of the micro spray bars, the interval between the water spray holes in the groups is smaller than the interval between the adjacent water spray holes in the groups, and meanwhile, the spray holes can be designed into flat holes or inclined holes with different angles more flexibly without influencing the action effect between the two groups of spray holes, and the allowance can be provided for adjusting the spraying route and the direction of the spray holes, so that the effect of covering the cross section of the whole dissolving tank is achieved; the filter that demineralized water spray pipe and little spray lance intercommunication department set up can filter the water that gets into little spray lance, avoids the hole for water spraying to block up, guarantees treatment effect, maintains the stable operation of system.
Furthermore, the urea dissolving tank is arranged below the ground, so that the conventional feeding device such as a bucket elevator can be omitted for one standby, and the space is effectively saved; meanwhile, the urea dissolving tank can be directly fed from the feed inlet by manpower, so that the crystallization corrosion of a channel after the bucket elevator runs for a long time is avoided, and the uncomfortable feeling caused by ammonia gas emission due to the drip leakage at the bottom of the tank body is reduced to a certain extent; and the urea dissolving tank is provided with an exhaust port, so that gas phase substances in the tank body can be timely discharged, and entrainment of excessive gas caused by lifting acting force is avoided.
According to the method, the demineralized water flushing spraying system is arranged to prevent the urea dissolving tank from crystallizing, the feeding filter screen is arranged between the gate valve of the dissolving tank and the urea crusher, one path of demineralized water is arranged above the feeding filter screen section, firstly, the flushing is carried out in time when the crystallization hardening of the gate valve of the feeding port is difficult, and secondly, the micro-spray rod in the urea dissolving tank is flushed when necessary, so that the urea crystallization deposition on the micro-spray rod is avoided; meanwhile, another path of desalted water is arranged at the stirring shaft center of the stirrer and sprayed out through a water spraying hole arranged on the micro spray rod, entrainment caused by stirring and temperature can be effectively restrained, the rising of water vapor is avoided, the problem that a urea crystallization plate of an opening connecting channel of a urea dissolving tank is dead is solved, the design is reasonable, the investment cost is low, and the crystallization hardening phenomenon can be effectively prevented.
Drawings
Fig. 1 is a schematic view of the structure of the device of the present invention.
FIG. 2 is a schematic diagram showing the positional relationship between a feed filter screen and a desalted water flushing inlet in the present invention.
FIG. 3 is a schematic cross-sectional view of a microjet according to the present invention.
FIG. 4 is a schematic cross-sectional view of a microjet according to the present invention.
In the figure: the device comprises a 1-desalted water main pipe, a 2-urea feed inlet, a 3-urea crusher, a 4-feed filter screen, a 5-dissolution tank gate valve, a 6-ground surface, a 7-desalted water flushing pipe, an 8-desalted water spraying pipe, a 9-stirrer, a 10-exhaust port, a 11-micro-spray rod, a 12-urea dissolution tank and a 13-discharge port.
Detailed Description
The invention will now be described in further detail with reference to specific examples, which are intended to illustrate, but not to limit, the invention.
Example 1
The device disclosed by the invention, as shown in figure 1, mainly comprises a urea dissolving tank 12, a urea crusher 3, a urea feeding port 2, a feeding filter screen 4, a dissolving tank gate valve 5, a stirrer 9, an exhaust port 10, a discharge port 13 and a desalted water flushing and spraying system; the demineralized water flushing and spraying system comprises a demineralized water main pipe 1, a demineralized water flushing pipe 7, a demineralized water spraying pipe 8 and a micro-spray rod 11; the upper part of the urea dissolving tank 12 is provided with a dissolving tank gate valve 5 and an exhaust port 10, and the bottom is provided with a discharge port 13; the urea crusher 3 is provided with a urea feeding port 2, and a feeding filter screen 4 is arranged between the urea crusher 3 and a dissolving tank gate valve 5; the demineralized water main pipe 1 is communicated with a demineralized water flushing pipe 7 and a demineralized water spraying pipe 8, and the demineralized water flushing pipe 7 is arranged at the top of the feeding filter screen 4, as shown in fig. 2; the stirring machine 9 is arranged in the urea dissolving tank 12, the micro-spray rod 11 is arranged at one end of the stirring shaft of the stirring machine 9 extending into the urea dissolving tank 12, and the desalted water spray pipe 8 is communicated with the micro-spray rod 11.
In practical application, the urea dissolving tank 12 is arranged below the ground 6, desalted water is added into the urea dissolving tank 12 through the desalted water flushing pipe 7, and the bagged urea is stacked on site and is difficult to absorb moisture and deliquesce to form blocks, and the bagged urea is directly poured into the urea dissolving tank 12 through the feed inlet of the urea crusher 3 after being manually unpacked. The urea is stacked for a long time, so that the urea is easy to absorb moisture and harden, is difficult to smash manually, and is smashed by the urea crusher 3, at the moment, a feeding filter screen 4 can remove large impurities such as nylon packaging bags, large-particle stones and the like found on site, and small particles pass through the feeding filter screen 4 and enter a urea dissolving tank 12 through a dissolving tank gate valve 5; closing the sluice valve 5 of the dissolving tank after the charging is completed;
then, starting a stirrer 9, and forming urea water solution by urea particles and desalted water entering a urea dissolving tank 12 under the stirring action of the stirrer 9;
in the stirring process of urea aqueous solution preparation, desalted water enters the urea dissolving tank 12 in two ways, one way directly sets a water inlet at the top of the feeding filter screen 4, and has two cleaning functions besides the function of a desalted water inlet, namely, the water inlet is timely washed when the crystallization hardening of the gate valve 5 of the dissolving tank is difficult, and the micro-spray rod 11 in the urea dissolving tank 12 is washed when necessary, so that the urea crystallization deposition on the micro-spray rod 11 is avoided; the other path of demineralized water is sprayed from a water spraying hole arranged on a micro spray rod 11 through an inlet at the stirring axis of a stirrer 9 through a demineralized water spraying pipe 8, entrainment caused by stirring and temperature can be effectively restrained, the rising of water vapor is avoided, a solute is brought out, and the problem of urea crystallization plate death of a perforated connecting channel of a urea dissolving tank 12 is solved.
In actual operation, the water inlet of the micro-spray rod 11 should be slowly opened to gradually reach rated working pressure so as to avoid damage to the water spraying device and the stirring shaft caused by instantaneous high pressure due to suddenly opening the valve.
As shown in figures 3 and 4, the micro-spray rod 11 is a round rod e with a certain diameter d, water spray holes are arranged at the bottom of the micro-spray rod 11 and uniformly distributed along the section width a of the micro-spray rod, and the aperture is only required to be a few millimeters; the included angle between the micro-spray rod 11 and the stirring shaft is 75-85 degrees, the invention is illustrated by taking 80 degrees as an example, the length of the micro-spray rod 11 is 8-12cm away from the tank body of the urea dissolving tank 12 by taking 10cm length as an example, and specific parameters are designed according to practical conditions. The water spraying holes are designed into inclined holes 2, the water spraying hole spacing b and the water spraying hole row spacing c can be adjusted according to the needs, and one hole is distributed in a W shape in a staggered way up and down; normally, the working pressure of the micro spray bar 11 is maintained between 0.05Mpa and 0.1Mpa. In specific application, round bars with the diameter of 25mm, the spacing of 2cm, the row spacing of 5cm and the arrangement of inclined 2 holes can be adopted, the aperture is about 0.5-0.9mm, and the rated working pressure is 0.1-0.2MPa.
Example 2
The invention relates to a method for preventing crystallization of a urea dissolving tank, which comprises the following steps on the basis of the device described in the embodiment 1,
firstly, adding desalted water into a urea dissolving tank 12 through a desalted water flushing pipe 7 by spraying and passing through a feeding filter screen 4, then adding crushed and impurity-removed urea particles into the urea dissolving tank 12, and closing a dissolving tank gate valve 5 after the addition is finished;
step 2, in the stirring process of urea aqueous solution preparation, desalted water is sent into a micro-spray rod 11 through a desalted water spray pipe 8 at the stirring axis of a stirrer 9, the working pressure of the micro-spray rod 11 is 0.05Mpa-0.1Mpa, and sprayed through a plurality of water spray holes, entrainment caused by stirring and temperature rise in a urea dissolving tank 12 is inhibited, and the open pore connecting channel of the urea dissolving tank 12 is prevented from being blocked by crystallization;
and 3, hardening crystals at the gate valve 5 of the dissolving tank and timely flushing urea crystals deposited on the micro-spray rod 11 by utilizing desalted water fed through a desalted water flushing pipe 7.
Claims (7)
1. A device for preventing crystallization of a urea dissolving tank, characterized in that: comprises a urea crusher (3) arranged outside a urea dissolving tank (12), a stirrer (9) arranged in the urea dissolving tank (12), and a demineralized water flushing and spraying system connected with the urea crusher (3) and the stirrer (9);
the discharging port of the urea crusher (3) is communicated with the feeding port of the urea dissolving tank (12), a dissolving tank gate valve (5) is arranged at the communicating position, and a feeding filter screen (4) is arranged between the discharging port of the urea crusher (3) and the dissolving tank gate valve (5);
the demineralized water flushing and spraying system comprises a micro-spray rod (11), a demineralized water main pipe (1), a demineralized water flushing pipe (7) and a demineralized water spraying pipe (8); the micro-spray rod (11) is fixedly arranged on a stirring shaft of the stirring machine (9) extending into the urea dissolving tank (12), and a plurality of water spraying holes communicated with the desalted water spraying pipe (8) are arranged on the micro-spray rod (11) at the axle centers of the stirring shafts; the water inlet end of the desalted water main pipe (1) is connected with external desalted water, and the water outlet end is respectively connected with the water inlet ends of the desalted water flushing pipe (7) and the desalted water spraying pipe (8); the water outlet end of the desalted water flushing pipe (7) is arranged above the feeding filter screen (4); the water outlet end of the desalted water spray pipe (8) is communicated with the micro spray rod (11);
the micro-spray bars (11) are arranged in a round bar shape, and two micro-spray bars are symmetrically arranged on the stirring shaft; the free end of the micro spray rod (11) is 8 cm to 12cm away from the tank body of the urea dissolving tank (12) and forms an included angle of 75 degrees to 85 degrees with the stirring shaft;
the water spraying Kong Caiyong is a flat hole or an inclined hole, and a plurality of water spraying holes are uniformly arranged at the bottom of the micro-spray rod (11) along the micro-spray rod (11).
2. A device for preventing crystallization of urea dissolving tank according to claim 1, characterized in that: the water spray holes are sequentially arranged at the bottom of the micro spray rod (11) in a W shape, every two water spray holes are in a group, and the distance between the water spray holes in the group is smaller than the distance between adjacent water spray holes between the groups; the diameter ratio of the aperture of the water spray hole to the diameter of the micro spray rod (11) is 0.02-0.04.
3. A device for preventing crystallization of urea dissolving tank according to claim 1, characterized in that: the filter is arranged at the communication position of the desalted water spray pipe (8) and the micro spray rod (11).
4. A device for preventing crystallization of urea dissolving tank according to claim 1, characterized in that: the urea dissolving tank (12) is arranged below the ground, the bottom of the urea dissolving tank is provided with a discharge hole (13), and an exhaust port (10) is arranged above the urea dissolving tank.
5. A method for preventing crystallization of urea dissolving tank, adopting the device as set forth in any one of claims 1-4, comprising,
firstly, adding desalted water into a urea dissolving tank (12) through a desalted water flushing pipe (7), then adding crushed and impurity-removed urea particles into the urea dissolving tank (12), and closing a dissolving tank gate valve (5) after the addition is finished;
step 2, in the stirring process of urea aqueous solution preparation, desalted water is sent into a micro-spray rod (11) through a desalted water spray pipe (8) at the stirring axis of a stirrer (9) and sprayed through a plurality of water spray holes, entrainment caused by stirring and temperature rise in a urea dissolving tank (12) is inhibited, and the open pore connecting channel of the urea dissolving tank (12) is prevented from being blocked by crystallization;
and 3, hardening crystals at a gate valve (5) of the dissolving tank and timely flushing urea crystals deposited on the micro-spray rod (11) by utilizing desalted water fed through a desalted water flushing pipe (7).
6. A method of preventing crystallization of a urea dissolving tank according to claim 5, characterized by: in the step 2, the working pressure of the micro spray rod (11) is 0.05Mpa-0.1Mpa.
7. A method of preventing crystallization of a urea dissolving tank according to claim 5, characterized by: the desalted water of the desalted water flushing pipe (7) enters the urea dissolving tank (12) through the feeding filter screen (4) by spraying.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810918256.9A CN108905761B (en) | 2018-08-13 | 2018-08-13 | Device and method for preventing urea dissolving tank from crystallizing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810918256.9A CN108905761B (en) | 2018-08-13 | 2018-08-13 | Device and method for preventing urea dissolving tank from crystallizing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108905761A CN108905761A (en) | 2018-11-30 |
| CN108905761B true CN108905761B (en) | 2023-11-17 |
Family
ID=64405497
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810918256.9A Active CN108905761B (en) | 2018-08-13 | 2018-08-13 | Device and method for preventing urea dissolving tank from crystallizing |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108905761B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115253963A (en) * | 2022-07-18 | 2022-11-01 | 华能国际电力股份有限公司大连电厂 | Equipment and method for preparing ammonia by urea pyrolysis and separating and purifying |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1857439A1 (en) * | 2006-05-17 | 2007-11-21 | Kemira GrowHow Oyj | Method for purifying aqueous urea solution |
| CN102207091A (en) * | 2011-06-07 | 2011-10-05 | 张意立 | High-concentration centrifugal pulp pump capable of spraying water on inner and outer corners |
| CN202199161U (en) * | 2011-09-13 | 2012-04-25 | 南京师范大学 | Spray feeding device of semi-sleeve continuous drum crystallizer |
| CN205495364U (en) * | 2016-03-02 | 2016-08-24 | 九洲天美环保科技（天津）有限公司 | Dissolving device for chemical industry convenient to material mixes and stirring |
| CN106902665A (en) * | 2017-05-02 | 2017-06-30 | 航天环境工程有限公司 | A kind of denitration system reducing agent urea solution prepare from stirring system |
| CN208878376U (en) * | 2018-08-13 | 2019-05-21 | 中国华能集团有限公司 | A kind of device for preventing urea dissolving tank from crystallizing |
-
2018
- 2018-08-13 CN CN201810918256.9A patent/CN108905761B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1857439A1 (en) * | 2006-05-17 | 2007-11-21 | Kemira GrowHow Oyj | Method for purifying aqueous urea solution |
| CN102207091A (en) * | 2011-06-07 | 2011-10-05 | 张意立 | High-concentration centrifugal pulp pump capable of spraying water on inner and outer corners |
| CN202199161U (en) * | 2011-09-13 | 2012-04-25 | 南京师范大学 | Spray feeding device of semi-sleeve continuous drum crystallizer |
| CN205495364U (en) * | 2016-03-02 | 2016-08-24 | 九洲天美环保科技（天津）有限公司 | Dissolving device for chemical industry convenient to material mixes and stirring |
| CN106902665A (en) * | 2017-05-02 | 2017-06-30 | 航天环境工程有限公司 | A kind of denitration system reducing agent urea solution prepare from stirring system |
| CN208878376U (en) * | 2018-08-13 | 2019-05-21 | 中国华能集团有限公司 | A kind of device for preventing urea dissolving tank from crystallizing |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108905761A (en) | 2018-11-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106621804B (en) | Flue gas ammonia injection mixing device and SCR flue gas denitration system | |
| CN208878376U (en) | A kind of device for preventing urea dissolving tank from crystallizing | |
| CN108905761B (en) | Device and method for preventing urea dissolving tank from crystallizing | |
| CN102350163B (en) | High-arsenic gold ore roasting flue gas treatment system and method for recovering arsenic and desulfurizing | |
| CN109051641A (en) | A kind of coal transporting trestle self-stripping system | |
| CN203725031U (en) | Parallel low-temperature SCR (Selective Catalytic Reduction) denitration device | |
| CN204261549U (en) | The purifying equipment of a kind of low temperature coke oven stack gases | |
| CN217121069U (en) | Washing device for powdery material | |
| CN215585971U (en) | Spray gun arrangement structure for SNCR (selective non-catalytic reduction) denitration system | |
| CN208279641U (en) | A kind of blast furnace slag flushing granulation tower equipped with auxiliary flushing cinder pipe | |
| CN212855649U (en) | Dust treatment structure of granulation device using urea as raw material | |
| CN206901049U (en) | SNCR systems anti-clogging urea tank | |
| CN202398456U (en) | Long jet range conical pneumatic nozzle | |
| CN203829913U (en) | Dust treatment device for ammonia flue gas desulphurization | |
| CN101157012B (en) | Urea granulation temperature reduction dust collection method and apparatus | |
| CN201050795Y (en) | Separated type flue gas desulfurizing and absorption tower | |
| CN219355852U (en) | SCR denitration system for preparing ammonia by catalyzing urea hydrolysis based on flue gas waste heat | |
| CN220375493U (en) | Belt feeder dust removal spraying system | |
| CN216062496U (en) | Coal laponite power generation burning exhaust gas processing apparatus | |
| CN204380882U (en) | A kind of shower nozzle of denitration spray gun | |
| CN109453911A (en) | A kind of self-cleaning nozzle | |
| CN217220881U (en) | UTG flue gas processing system in manufacturing | |
| CN214972997U (en) | Prevent stifled exhaust-heat boiler denitration and spout ammonia device | |
| CN214809816U (en) | High efficiency spray set | |
| CN215782722U (en) | Prevent that SCR deNOx systems deposition from and promote stifled equipartition device that prevents of flow field homogeneity |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |