CN108871027A - A kind of chemical regeneration method and system of melamine hot gas cooler and hot-air filter - Google Patents
A kind of chemical regeneration method and system of melamine hot gas cooler and hot-air filter Download PDFInfo
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- CN108871027A CN108871027A CN201710326146.9A CN201710326146A CN108871027A CN 108871027 A CN108871027 A CN 108871027A CN 201710326146 A CN201710326146 A CN 201710326146A CN 108871027 A CN108871027 A CN 108871027A
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- hot gas
- hot
- high temperature
- filtration unit
- cold filtration
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D17/00—Regenerative heat-exchange apparatus in which a stationary intermediate heat-transfer medium or body is contacted successively by each heat-exchange medium, e.g. using granular particles
- F28D17/005—Regenerative heat-exchange apparatus in which a stationary intermediate heat-transfer medium or body is contacted successively by each heat-exchange medium, e.g. using granular particles using granular particles
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/66—Regeneration of the filtering material or filter elements inside the filter
- B01D46/80—Chemical processes for the removal of the retained particles, e.g. by burning
- B01D46/84—Chemical processes for the removal of the retained particles, e.g. by burning by heating only
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/584—Recycling of catalysts
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Filtering Of Dispersed Particles In Gases (AREA)
Abstract
The present invention provides in a kind of Melamine Production, the chemical regeneration method of hot gas cooler and hot-air filter, by being passed through water vapour to postrun hot gas cooler and/or filter, and provide hot environment, make wherein remaining by-product by chemical reaction generate gas remove, realize regeneration.The present invention also provides during Melamine Production, the online switching and chemical regeneration method of hot gas cooler and hot-air filter, by two sets of hot gas cold filtration units in parallel, switching is used, and is switched the unit to get off and is passed through chemical reaction regeneration.The present invention also provides the regenerative systems of Melamine Production equipment.It is short that method and system of the invention fundamentally solves hot gas cold filtration unit service life, need the problem of manually cleaning, so that hot gas cold filtration unit is remained high heat transfer efficiency and lower resistance state, to maintain device long-period stable operation, and reduces the power consumption of Carrier Gas Compressor.
Description
Technical field
The invention belongs to chemical field, it is related to the chemical regeneration side of a kind of melamine hot gas cooler and hot-air filter
Method.
Background technique
Currently, melamine is usually produced by raw material of urea, production method can be divided into low-pressure process and two kinds of high-pressure process.
High-pressure process preparation technology of melamine belongs to liquid phase reactor, no catalyst.Reaction pressure is generally 7~20MPa, instead
Answering temperature is 360~400 DEG C.
Low-pressure process preparation technology of melamine belongs to gas phase catalytic reaction, is generally urged with aluminium oxide, Alusil or silica gel
Agent.Reaction pressure is generally 0.1~0.7MPa, and reaction temperature is 350~400 DEG C.
Low-pressure process preparation technology of melamine generally uses gas phase quenching technique to post-process reaction product, i.e., with ammonia
Gaseous mixture with carbon dioxide is the crystallization and purification that quenching medium completes product.
In recent years, with the fast development of China's melamine industry, domestic melamine production capacity has accounted for world's total output energy
60% or more, wherein the large-scale melamine plant about 80% for producing 30000 tons or more per year is all using low-pressure process gas phase quenching
Technique, which is gas phase catalytic reaction, and in fluidized-bed reactor, following reaction occurs：
Side reaction：
In existing low-pressure process gas phase quenching technique, from fluidized-bed reactor export generation gas in addition to carrier gas (ammonia and
Carbon dioxide), outside melamine, also contain by-product (sweet primary amine and melem) and a small amount of catalyst fines.In order to remove pair
Product and catalyst fines, 390 DEG C of reaction generation gas need to first pass through hot gas cooler and are cooled to 340 DEG C, make by-product (honey
Primary amine and melem) being sublimated by gas phase becomes solid, enters back into hot-air filter filtering, and removing by-product, (sweet primary amine and honey are strangled
Amine) and a small amount of catalyst fines, enter back into crystallizer crystallization.
Existing hot gas cooler uses tubular heat exchanger pattern, and process gas, the raw liquid cooling heat transferring in the road Guan Waiwei are walked in pipe.?
In heat exchanger tube, the whole crystallizations of sublimating of by-product (sweet primary amine and melem) become solid phase, also can be because of office there are also a small amount of melamine
Portion is subcooled and sublimates and crystallize into solid phase, these crystalline solids will be adhered in heat transfer tube wall together with catalyst fines, be made
Hot gas cooler heat transfer efficiency decline, resistance increase, about 2 months or so will cleaning during shutdown (generally using high pressure water it is clear
It washes).
Existing hot-air filter is filtered using glass fibre filter bag, is carried out although with blowback method to screen pipe
Online blowback, to slow down the rate of climb of filter resistance, but since the caking property of by-product (sweet primary amine and melem) is strong, with
The passage of time, blowback effect be gradually reduced, filter resistance will be increasing, about 1 month or so, filter resistance
70KPa will be risen to from 10KPa, it is necessary to which parking clears up and replaces filter bag.
For hot gas cooler and the defect of hot-air filter technology, domestic some research institutions and manufacturer are proposed
Many solutions, for example use the heat exchange area for amplifying hot gas cooler, the filter area for increasing hot-air filter, increased
The measures such as the blowback frequency of filter or use multiple devices parallel connection are spare.However these measures use is all physical mechanical side
Method opposite can only extend some service life, and it doesn't solve the problem fundamentally.Such as patent CN 10477006A, use
Fluidized-bed reactor is successively connected with hot gas cooler, primary cyclone, hot-air filter, then a set of hot gas in parallel is cooling
Device, primary cyclone and hot-air filter, the device that finally decrystallizes crystallization, by controlling motor-driven valve, so that any cooling
Device can mutually switch use with any hot-air filter.Although this method reduces the switching times of hot-air filter
50%, but the hot gas cooler switched switches the hot-air filter to get off and is also required to manually there is still a need for artificial cleaning
Cleaning and replacement filter bag are solved the problems, such as without fundamentally upper.
Summary of the invention
One of the objects of the present invention is to provide a kind of by chemical breakdown, and to be adhered to the hot gas in Melamine Production cold
But the method for by-product (sweet primary amine and melem) and melamine on device and/or hot-air filter so that hot gas cooler and
Hot-air filter can reuse.
Another object of the present invention is to provide a kind of hot gas cooler of Melamine Production and the changes of hot-air filter
Learn regeneration method.
It sets another object of the present invention is to provide during a kind of Melamine Production, low energy consumption, operating cost is low
Standby regeneration method.
Another object of the present invention is to provide the hot gas coolers and/or hot gas mistake in a kind of Melamine Production system
The chemical regeneration system of filter.
Another object of the present invention is to provide a kind of cycle of operation length, the Melamine Production of safe and stable operation and set
Standby regenerative system.
The purpose of the present invention is realized by following technological means：
On the one hand, the present invention provides a kind of for the hot gas cooler of Melamine Production and the chemistry of hot-air filter
Regeneration method, which is characterized in that the method is to be passed through water vapour to hot gas cooler and/or hot-air filter；And to heat
At least its internal offer hot environment of Gas Cooler and/or hot-air filter.
It is known in the art that during Melamine Production, hot gas cooler and hot-air filter after a period of use,
On hot gas heat-exchange tube of cooler inner wall and on hot-air filter filter bag, melamine and melamine by-product can be stained with
The particles such as sweet primary amine, melem and a small amount of catalyst need cleaning during shutdown or replacement filter bag.
The present invention is for the hot gas cooler of Melamine Production and the chemical regeneration method of hot-air filter, by heat
Gas Cooler and/or hot-air filter are passed through water vapour, and hot gas cooler and/or hot-air filter is maintained to be in high temperature ring
Border, by chemically reacting solid particles point such as melamine, sweet primary amine, melems in hot gas cooler and hot-air filter
Solution is removed at gas.
The reaction principle of chemical regeneration：
It is adhered on hot gas heat-exchange tube of cooler inner wall and the melamine on hot-air filter filter bag, sweet primary amine, honey
It is 300~400 DEG C that amine etc., which is strangled, in temperature, and pressure is 0.01~2.0MPa, and has the catalyst such as silica gel or Alusil or aluminium oxide
Under the conditions of existing, ammonia and carbon dioxide can be generated with steam reaction, realize hot gas cooler and hot-air filter again
It is raw, without cleaning during shutdown and replacement filter bag.
As preferred embodiment, high temperature ring at least is provided inside it to hot gas cooler and/or hot-air filter
Border is 300 DEG C or more, preferably 300 DEG C~400 DEG C；More preferable 350 DEG C~400 DEG C.This is because temperature is too low, it is unfavorable for being catalyzed
The generation of reaction, temperature is too high, then the glass fibre filter bag of hot-air filter is easy aging.
As preferred embodiment, by being passed through high temperature carrier gas to hot gas cooler and/or hot-air filter, for it
Inside provides hot environment；It is therefore preferred that control high temperature carrier gas temperature at 300 DEG C or more, preferably 300 DEG C~400 DEG C,
More preferable 350 DEG C~400 DEG C.In addition, unexpectedly, water vapor concentration can be prevented excessively high by being passed through high temperature carrier gas,
Not exclusively, unreacted water vapour, which enters rear workshop section, influences the consumption of melamine for reaction, and can prevent regeneration gas distribution not
It uniformly causes to regenerate non-uniform phenomenon generation, it is highly beneficial for regenerative response.
As preferred embodiment, maintain the pressure of hot gas cooler and/or hot-air filter in 0.1~0.7MPa.
Remain melamine conjunction in the hot gas cooler and/or hot-air filter before regeneration or in regenerative process
Generated by-product and used catalyst in, or optionally, also remain melamine；
The by-product is one or both of close primary amine or Miller amine；
The catalyst is at least one of silica gel, Alusil, aluminium oxide；
The high temperature carrier gas is at least one of ammonia, carbon dioxide, nitrogen；It is highly preferred that the high temperature carries
Gas is ammonia and carbon dioxide；Preferably, the high temperature carrier gas is the fluidized carrier gas of melamine synthesis, i.e. ammonia and two
Carbonoxide.
As preferred embodiment, in Melamine Production, hot gas cooler is connect with hot-air filter, it is only necessary to heat
Gas Cooler import is passed through water vapour and provides hot environment, so that it may realize the common chemical of hot gas cooler and hot-air filter
Reaction regeneration.
On the other hand, the present invention also provides a kind of regeneration methods of equipment during melamine.It is raw in melamine
During production, raw material urea is reacted through catalyst in the reactor, generates gaseous melamine and by-product, gaseous state trimerization
Cyanamide and by-product are exported from reactor outlet, and the hot gas cold filtration unit by being connected to reactor, and by-product is in warm
Air cooling filter element, which is sublimated, to be become solid-state and is trapped to separate with gaseous melamine.Preferably, the gaseous state three
When poly cyanamid and by-product are exported from reactor outlet, a small amount of catalyst fines are also taken out of, hot gas cold filtration unit is retaining
It is gone back when by-product while having retained catalyst fines；In the hot gas cold filtration unit, caused because of local overcooling a small amount of
Melamine sublimate and crystallize into solid phase, so being also possible to remain melamine.
The regeneration method of equipment is during Melamine Production of the invention：Reactor parallel connection at least two sets of hot gas are cold
But filter element comprising following steps：
1) during Melamine Production, at least a set of hot gas cold filtration unit be in can operating status, reactor
First connection can be a set of in the hot gas cold filtration unit of operating status, and the set hot gas cold filtration unit is in operation shape at this time
State retains the by-product escaped from reactor, and by-product is accumulated in the set hot gas cold filtration list becomes the cold of load
But filter element；
2) during continuous production, the cold filtration unit of load described in step 1) is switched into life from operating status
Produce off-line state；It is another set of in can operating status hot gas cold filtration unit be then switched to be connected to reactor in run
State, the production process for continuing to serve melamine is to retain by-product；
3) the hot gas cold filtration unit in production off-line state, by before being switched to operating status next time, into
Row regeneration and become can operating status hot gas cold filtration unit；The regenerative process is：It is logical to hot gas cold filtration unit
Enter water vapour, and provides hot environment to hot gas cold filtration unit.
As preferred embodiment, in step 2), the hot gas cold filtration unit be in can operating status refer to
The resistance of hot-air filter in the unit is 20KPa or less；It is preferred that 15kPa or less；More preferable 10KPa.
As preferred embodiment, in step 2), when the resistance of the hot gas cold filtration unit of load rises to 20KPa
Or more when, switch the operation of another set of hot gas cold filtration unit.
As a preferred embodiment, by being passed through high temperature carrier gas to hot gas cold filtration unit, coming in step 3)
Hot environment is provided for its inside；Preferably, the high temperature carrier gas is at least one of ammonia, carbon dioxide, nitrogen；More
Preferably, the high temperature carrier gas is ammonia and carbon dioxide.The temperature of the hot environment or high temperature carrier gas at 300 DEG C or
More than；Preferably, 300 DEG C~400 DEG C；It is highly preferred that 350 DEG C~400 DEG C.
As a preferred embodiment, after water vapour is mixed with high temperature carrier gas, then being passed through hot gas together in step 3)
Cold filtration unit.
As a preferred embodiment, in step 3), maintain the pressure of hot gas cold filtration unit 0.1~
0.7MPa。
Wherein, in step 3), regenerative process occur chemical reaction generate product gas be ammonia and carbon dioxide, and
It is removed from hot gas cold filtration unit.
As preferred embodiment, in step 3), after chemical reaction, also to the heat in hot gas cold filtration unit
Air filter carries out blowback；After blowback at least one is taken turns, ash discharge is carried out to hot-air filter；It is highly preferred that the blowback is rotation
Turn blowback；It is highly preferred that the blowback is 1~3 wheel.
On the other hand, the present invention also provides a kind of chemical regeneration system of equipment, the equipment is Melamine Production
Hot gas cooler and/or hot-air filter in system；The regenerative system contains hot gas cooler and hot-air filter, also
Containing water vapour conveying mechanism, to convey water vapour into hot gas cooler and/or hot-air filter；
High temperature is for warm mechanism, to provide hot environment to hot gas cooler and/or hot-air filter.
As preferred embodiment, the high temperature for warm mechanism be carrier gas conveying mechanism, to hot gas cooler and/
Or high temperature carrier gas is conveyed in hot-air filter；Preferably, the high temperature carrier gas be ammonia, carbon dioxide, in nitrogen at least
It is a kind of；It is highly preferred that the high temperature carrier gas is ammonia and carbon dioxide.Hot environment or the temperature of high temperature carrier gas are at 300 DEG C
Or more；Preferably, 300 DEG C~400 DEG C；It is highly preferred that 350 DEG C~400 DEG C.
As a preferred embodiment, hot gas cooler rear end is connected with hot-air filter front end becomes hot gas
Cold filtration unit.The water vapour conveying mechanism and the high temperature are respectively connected to hot gas cold filtration list for warm mechanism
The front end of member；Alternatively, the water vapour conveying mechanism converges in transfer pipeline with the high temperature for both warm mechanisms in advance
After conjunction, it is then connected to the front end of hot gas cold filtration unit.
Alternatively, the water vapour conveying mechanism and/or high temperature separate two line branchings, a connection institute for warm mechanism
State hot gas cooler front end, a connection hot-air filter front end；Or the water vapour conveying mechanism and/or high temperature
Two line branchings are separated for warm mechanism, the elder generation of branch on steam conveyor tube road and high temperature converge for the transfer pipeline branch of warm mechanism
After conjunction, then it is separately connected the hot gas cooler and hot-air filter.
Further, the water vapour conveying mechanism, high temperature contain shared or independent conveyance conduit for warm mechanism,
And the first control device by being located on conveyance conduit is connect with the hot gas cold filtration unit, to realize connected state
The switching of state and disconnected state.
As a preferred embodiment, hot gas cooler described in a kind of chemical regeneration system of equipment of the invention
Front end be also connected with melamine reactor；The process gas conveying that the melamine reactor is connect with hot gas cooler
Second control device is equipped in pipeline, to control connection or not be connected to；Also, the first control device of the conveyance conduit
The pipeline of second control device front end in the pipeline of front end, with process gas transfer pipeline, the two are independent tubes；And after them
The pipeline at end, the two are independent pipeline or merge shared pipeline.
As a preferred embodiment, a kind of chemical regeneration system of equipment of the invention, the hot gas filtration
Device rear end is also connected with crystallizer；Preferably, the hot-air filter is set in the process gas transfer pipeline that crystallizer connects
There is third control device, to control connection or not be connected to.
As preferred embodiment, the second control device and third control device are electric gate valve.
As preferred embodiment, the melamine reactor front end of the chemical regeneration system of the equipment is connected with
Carrier gas preheater.
When high temperature of the present invention is carrier gas conveying mechanism for warm mechanism, as preferred embodiment, carrier gas conveying mechanism
A carrier gas source is shared with melamine reactor, the carrier gas of the carrier gas source is divided into two-way after carrier gas preheater, and one
Road connects melamine reactor, connects hot gas cooler and/or hot-air filter all the way.
On the other hand, the present invention also provides a kind of Melamine Production and equipment regenerative system, contain two in the system
Set or above hot gas cold filtration unit, further include the reactor before being connected to hot gas cold filtration unit, and connection
Crystallizer after hot gas cold filtration unit.
Every set hot gas cold filtration unit of the system is connected with：
Water vapour conveying mechanism, to convey water vapour into the hot gas cold filtration unit of every set parallel connection；
High temperature is for warm mechanism, to provide hot environment to the hot gas cold filtration unit of every set parallel connection.
The high temperature is carrier gas conveying mechanism for warm mechanism, to convey into hot gas cooler and/or hot-air filter
High temperature carrier gas；Preferably, the high temperature carrier gas is at least one of ammonia, carbon dioxide, nitrogen；It is highly preferred that described
High temperature carrier gas be ammonia and carbon dioxide.Hot environment or the temperature of high temperature carrier gas are at 300 DEG C or more；Preferably, 300 DEG C
~400 DEG C；It is highly preferred that 350 DEG C~400 DEG C.
As a preferred embodiment, the equipment of the invention is hot gas cooler rear end and hot gas mistake
The series connection of filter front end becomes hot gas cold filtration unit.The vapor conveying mechanism and the high temperature are distinguished for warm mechanism
It is connected to the front end of hot gas cold filtration unit；Alternatively, the vapor conveying mechanism and the high temperature are for warm mechanism two
After person converges in transfer pipeline in advance, it is then connected to the front end of hot gas cold filtration unit.
Alternatively, the vapor conveying mechanism and/or high temperature separate two line branchings, a connection institute for warm mechanism
State hot gas cooler front end, a connection hot-air filter front end；Or the vapor conveying mechanism and/or high temperature
Two line branchings are separated for warm mechanism, the elder generation of branch of vapor transfer pipeline and high temperature converge for the transfer pipeline branch of warm mechanism
After conjunction, then it is separately connected the hot gas cooler and hot-air filter.
Further, the water vapour conveying mechanism, high temperature contain shared or independent conveyance conduit for warm mechanism,
And the first control device by being located on conveyance conduit is connect with the hot gas cold filtration unit, to realize connected state
The switching of state and disconnected state.
As a preferred embodiment, hot gas cooler described in a kind of chemical regeneration system of equipment of the invention
Front end be also connected with melamine reactor；The process gas conveying that the melamine reactor is connect with hot gas cooler
Second control device is equipped in pipeline, to control connection or not be connected to；Also, the first control device of the conveyance conduit
The pipeline of second control device front end in the pipeline of front end, with process gas transfer pipeline, the two are independent tubes；And after them
The pipeline at end, the two are independent pipeline or merge shared pipeline.
As a preferred embodiment, hot-air filter described in a kind of chemical regeneration system of equipment of the invention
Rear end is also connected with crystallizer；Preferably, it is equipped in the process gas transfer pipeline that the hot-air filter is connect with crystallizer
Third control device, to control connection or not be connected to.
As preferred embodiment, in the present invention, the second control device and third control device are electric brake
Valve.
In Melamine Production of the present invention and equipment regenerative system, the hot gas cold filtration unit of every set parallel connection
A water vapour conveying mechanism and a high temperature are separately connected for warm mechanism；Alternatively, every set is in parallel as preferred embodiment
Hot gas cold filtration unit connect a water vapour conveying mechanism and a high temperature jointly for warm mechanism, it is specifically, described
Water vapour conveying mechanism/high temperature is divided into corresponding for the delivery pipe of warm mechanism according to the tricks of hot gas cold filtration unit in parallel
The high temperature of quantity is respectively connected to hot gas cold filtration unit for warm mechanism delivery pipe branch group/steam conveyor tube branch group
Front end；Alternatively, the steam conveyor tube branch group and the high temperature first converge two-by-two for warm mechanism delivery pipe branch group
After conjunction, then it is connected to every set hot gas cold filtration unit front end one by one.Alternatively, the steam conveyor tube conveying mechanism/height
Temperature is further divided into two secondary branch for each branch group of warm mechanism, and two of the steam conveyor tube conveying mechanism are secondary
Grade branch is connected respectively to hot gas cooler leading portion and hot-air filter front end, two for warm mechanism delivery pipe of the high temperature
Secondary branch is also connected to hot gas cooler leading portion and hot-air filter front end；Or the steam conveyor tube conveying
Mechanism and high temperature for warm mechanism secondary branch, after converging two-by-two, in the front end for being connected to hot gas cooler and hot-air filter；
As preferred embodiment, the melamine reactor front end of the chemical regeneration system of the equipment is connected with
Carrier gas preheater.
As preferred embodiment, when high temperature of the present invention is carrier gas conveying mechanism for warm mechanism, carrier gas conveying mechanism
A carrier gas source is shared with melamine reactor, the carrier gas of the carrier gas source is divided into two-way after carrier gas preheater, and one
Road connects melamine reactor, connects hot gas cooler filter element all the way.Connect the carrier gas of hot gas cooler filter element
Delivery pipe is divided into the high temperature of respective numbers for warm mechanism delivery pipe branch further according to the tricks of hot gas cold filtration unit in parallel
Group/steam conveyor tube branch group, is respectively connected to the front end of hot gas cold filtration unit；Alternatively, the water vapour conveys
Pipe branch group and the high temperature are for warm mechanism delivery pipe branch group, and after first converging two-by-two, then to be connected to every set hot gas one by one cold
But filter element front end.
As preferred embodiment, the delivery pipe of the water vapour conveying mechanism of every set hot gas cold filtration unit connection/
First control device in its branch, contains restriction orifice and gate valve；The position of restriction orifice and gate valve can be exchanged, and that is to say
Say, the first control device is successively arranged restriction orifice and gate valve to direction along water vapor stream, alternatively, be successively arranged gate valve and
Restriction orifice.
It is known in the art that gas can be generated under the action of water vapour and catalyst in melamine and its production by-product
Body carbon dioxide and ammonia, however, for during Melamine Production, the service life of hot gas cooler and hot-air filter
Short technological deficiency, never someone expect that also never someone uses the reaction, remove residual in hot gas cooler and hot-air filter
The melamine and by-product stayed realizes the regeneration of hot gas cooler and hot-air filter.
Improvement of the invention is, the silica gel or silicon that itself is adhered on hot gas cold filtration unit is dexterously utilized
Aluminium glue or aluminium oxide make catalyst, react with melamine, sweet primary amine, melem respectively and generate ammonia and titanium dioxide water vapour
Carbon can make hot gas cold filtration regeneration unit without additional addition catalyst, without artificial cleaning, filter without replacement
Bag, dramatically reduces cost of human and material resources, and the service life for fundamentally solving hot gas cold filtration unit short is asked
Topic.For catalyst fines remaining after regenerative response, because remaining catalyst fines viscosity very little, the present invention are further led to
Cross the rotary back-blowing and automatic ash discharge system of hot-air filter, it is easy to drain remaining particulate matter.
A further improvement of the present invention is that a hot gas cooler is used to connect with a hot-air filter as a set of heat
Air cooling filter element is arranged in parallel 2 sets or more of hot gas cold filtration unit in fluidized-bed reactor outlet, passes through control heat
Electric gate valve before and after air cooling filter element uses the switching of any hot air cooling filter element, it is cold to switch the hot gas to get off
But for filter element using water vapour chemical reaction regeneration, the hot gas cold filtration unit after regeneration can be spare.
A further improvement of the present invention is that matching steam regeneration using high temperature carrier gas, water vapor concentration mistake can be prevented
Height, not exclusively, unreacted water vapour, which enters rear workshop section, influences the consumption of melamine, and regeneration gas can be prevented to be distributed for reaction
It unevenly causes to regenerate non-uniform phenomenon generation, while the temperature of regenerative response can also be maintained, avoid temperature too low and influence
The progress of regenerative response.
A further improvement of the present invention is that hot-air filter uses rotary back-blowing technology, blowback effect had not only been improved, but also
It ensure that the long-term operation of equipment.
A further improvement of the present invention is that switching online using hot gas cold filtration unit and regeneration techniques, make hot gas
Cold filtration unit remains high heat transfer efficiency and lower resistance state, to maintain device long-period stable operation, and reduces load
The power consumption of air compressor.
Method and system of the invention had not only had the advantages that regenerative operation was easy, regeneration cost is low, but also had regeneration efficiency
The high, advantages such as device is stable, power consumption is low.
Detailed description of the invention
Fig. 1 shows hot gas cooler and/or hot gas in a kind of Melamine Production system of the embodiment of the present invention 3
The chemical regeneration system schematic of filter.
Fig. 2 shows hot gas cooler and/or hot gas in a kind of Melamine Production system of the embodiment of the present invention 4
The chemical regeneration system schematic of filter.
Fig. 3 shows hot gas cooler and/or hot gas in a kind of Melamine Production system of the embodiment of the present invention 5
The chemical regeneration system schematic of filter.
Fig. 4 shows a kind of Melamine Production and equipment regenerative system schematic diagram of the embodiment of the present invention 6.
Fig. 5 shows a kind of Melamine Production and equipment regenerative system schematic diagram of the embodiment of the present invention 7.
Schema explanation：
1- carrier gas preheater 2- fluidized-bed reactor
I 4- hot gas cooler II of 3- hot gas cooler
I 6- hot-air filter II of 5- hot-air filter
I 8- electric gate valve II of 7- electric gate valve
III 10- electric gate valve IV of 9- electric gate valve
I 12- regulating valve II of 11- regulating valve
I 14- gate valve II of 13- gate valve
I 16- restriction orifice II of 15- restriction orifice
17- high temperature carrier gas conveying mechanism 18- water vapour conveying mechanism
I 20- rotary back-blowing device II of 19- rotary back-blowing device
It is although denoted as " by-product " in present invention diagram from the substance that hot-air filter lower end is discharged, but " by-product " is only
For from one kind in the substance being discharged in hot-air filter, however not excluded that other discharged substances, for example, catalyst fines are connected to
By-product is discharged together.
Specific embodiment
Technical solution of the present invention is further illustrated below by way of specific embodiment, and specific embodiment does not represent to this hair
The limitation of bright protection scope.Other people according to the present invention theory made it is some it is nonessential modification and adjustment still fall within this hair
Bright protection scope.
In the present invention, the effect of " the hot gas cold filtration unit " is retention during Melamine Production
The melamine by-product and a small amount of catalyst fines escaped from reactor, there are also a small amount of melamine reaction gas because of office
Portion's supercooling, can also crystallize, remain in hot gas cold filtration unit；Common hot gas cold filtration unit includes hot gas cooler
And the hot-air filter being attached thereto.In patent CN 10477006A, use fluidized-bed reactor successively cooling with hot gas
Device, primary cyclone, hot-air filter are connected, then a set of hot gas cooler in parallel, primary cyclone and hot gas mistake
Filter, the device that finally decrystallizes crystallization.Primary cyclone is provided between its hot gas cooler and hot-air filter, it is therefore an objective to
In order to which separate section melamine by-product and catalyst fines extend hot gas mistake to mitigate the filtering load of hot-air filter
The service life of filter.And in the present invention, in hot gas cold filtration unit completely without setting primary cyclone, because
After using regeneration techniques, the catalyst fines on hot-air filter filter bag are easy to be got off by blowback, if adding primary
Cyclone separator, unfavorable instead, unfavorable factor has：1. regenerate, needs to regenerate the primary cyclone, increase regeneration
Time and cost.2. needing to increase the bottom dust removing system of a set of primary cyclone, operation difficulty is increased.3. increasing
Equipment investment.
In the present invention, the preparation technology of melamine is low-pressure process preparation technology of melamine.
In the present invention, high temperature carrier gas conveying mechanism, which refers to, provides the equipment and high temperature carrier gas delivery line of the carrier gas of high temperature.
In the present invention, water vapour conveying mechanism, which refers to, provides the equipment and steam conveyor tube road of water vapour.
In the present invention, the process gas is the gas recycled in process system, and main component is ammonia and two
Carbon dioxide gas mixture (contains melamine in the process gas between fluidized-bed reactor and crystallizer, into fluidized-bed reaction
Melamine is free of in process gas before device).
" front end " of signified equipment of the invention refers to its inlet end, i.e., the one of the air inlet of gas flow in process flow
End.
Embodiment 1 is a kind of for the hot gas cooler of Melamine Production and the chemical regeneration method of hot-air filter
During low-pressure process Melamine Production, when hot gas cooler and hot-air filter after a period of use,
On hot gas heat-exchange tube of cooler inner wall and on hot-air filter filter bag, melamine and melamine by-product can be stained with
The particles such as sweet primary amine, melem and a small amount of catalyst fines need stop cleaning or replacement filter bag.
At this point, stop the operation of the hot gas cooler and hot-air filter, it is logical to hot gas cooler and/or hot-air filter
Enter water vapour；And maintain the temperature of hot gas cooler and/or hot-air filter at 300 DEG C or more, 0.1~0.7MPa of pressure it
Between, in hot gas cooler and/or hot-air filter under the action of remaining catalyst, by chemically reacting hot gas cooler
And the decomposition such as melamine, sweet primary amine, melem in hot-air filter generate gas (ammonia and carbon dioxide) and remove.
As preferred embodiment, maintain the temperature of hot gas cooler and/or hot-air filter at 300 DEG C~400 DEG C；
More preferable 330 DEG C -360 DEG C.
As preferred embodiment, when being passed through water vapour, it is passed through high temperature carrier gas (ammonia and carbon dioxide), also to mention
The regenerative response temperature of heat supply Gas Cooler and/or hot-air filter；It is therefore preferred that the temperature of control high temperature carrier gas is 300
DEG C or more, preferably 300 DEG C~400 DEG C, more preferable 350 DEG C~400 DEG C.When hot gas cooler is connected with hot-air filter, only
Being passed through gas in hot gas cooler can make hot gas cooler and hot-air filter that regenerative response occur.
Equipment regeneration method during a kind of Melamine Production of embodiment 2
A kind of equipment regeneration method in Melamine Production device procedures, melamine fluidized-bed reactor are two sets in parallel
(in specific production, can be two sets, be also possible to cover) hot gas cold filtration unit, hot gas cold filtration unit tandem junction again more
Brilliant device, the hot-air filter that the hot gas cold filtration unit contains hot gas cold air device and is attached thereto, operating procedure is such as
Under：
1) when Melamine Production, at least a set of hot gas cold filtration unit be in can operating status, fluidized-bed reactor
First connection can be a set of in the hot gas cold filtration unit of operating status, and the set hot gas cold filtration unit is in operation shape at this time
State retains the by-product escaped from reactor, and by-product is accumulated in the set hot gas cold filtration list becomes the cold of load
But filter element, waste hot air cold filtration unit are in production off-line state.
2) when the hot gas cold filtration unit resistance of operation rises to 20KPa or more, need to clean hot gas cooler
And hot-air filter, when replacing the filter bag of hot-air filter, stop the operation of the hot gas cold filtration unit, unit switching
To produce off-line state；It is another set of in can the hot gas cold filtration unit of operating status be then switched to be connected to reactor and be in
Operating status, the production process for continuing to serve melamine is to retain by-product；Melamine Production system during being somebody's turn to do
Remaining equipment such as fluidized-bed reactor, crystallizer etc. be constantly in production presence；
3) the hot gas cold filtration unit in production off-line state, by before being switched to operating status next time, into
Row regeneration and become can operating status hot gas cold filtration unit.Specifically, it is passed through water vapour to hot gas cold filtration unit,
And maintaining the temperature of hot gas cold filtration unit at 300 DEG C or more, pressure is in 0.1~0.7MPa；Make hot gas cold filtration unit
In melamine and its by-product under the effect of the catalyst, by chemical reaction generate gas (ammonia and carbon dioxide),
And entering by crystallizer is exhaust treatment system.As a preferred embodiment, hot gas cooler and/or hot gas mistake are maintained
The temperature of filter is at 300 DEG C~400 DEG C；Embodiment more preferably, maintenance hot gas cooler and/or hot-air filter
Temperature is at 330 DEG C~360 DEG C.As a preferred embodiment, when being passed through water vapour, while to hot gas cold filtration unit
It is passed through high temperature carrier gas, to maintain the regenerative response temperature of hot gas cooler and/or hot-air filter；It is therefore preferred that control is high
The temperature of warm carrier gas is at 300 DEG C or more, and preferably 300 DEG C~400 DEG C, more preferable 350 DEG C~400 DEG C.In addition, by being passed through high temperature
Carrier gas can prevent water vapor concentration excessively high, and not exclusively, unreacted water vapour, which enters rear workshop section, influences melamine for reaction
Consumption, and regeneration gas can be prevented to be unevenly distributed and cause to regenerate non-uniform phenomenon generation.After chemical reaction, start quilt
The back-blowing device of the hot-air filter of regenerative response carries out rotary back-blowing；After blowback 1~3 is taken turns, starting hot-air filter is arranged automatically
Grey program carries out ash discharge.
As preferred embodiment, after water vapour is mixed with high temperature carrier gas, then it is passed through hot gas cold filtration unit together；
As preferred embodiment, be passed through hot gas cold filtration unit high temperature carrier gas can be passed through fluidized-bed reaction
The carrier gas of device uses same carrier gas source.
As preferred embodiment, the hot gas cold filtration unit be in can operating status refer in the unit
The resistance of hot-air filter is 20KPa or less；It is preferred that 15kPa or less；More preferable 10KPa.
The chemical regeneration system of hot gas cooler and/or hot-air filter in a kind of Melamine Production system of embodiment 3
System
The chemical regeneration system of hot gas cooler and/or hot-air filter in Melamine Production system as shown in Figure 1
System, the system contain a set of hot gas cold filtration unit, and hot gas cold filtration unit contains hot gas cooler I 3 and is attached thereto
Hot-air filter I 5.The front end of hot gas cold air device I 3, is connected with water vapour conveying mechanism 18, to hot gas cold filtration
Unit transportation water vapour is also connected with high temperature for warm mechanism, and the high temperature is high temperature carrier gas for warm mechanism in the present embodiment
Conveying mechanism 17, to provide hot environment to hot gas cooler I 3 and hot-air filter I 5.The delivery pipe and height of water vapour
The delivery pipe of warm carrier gas is connected respectively to 3 front end hot gas cooler I.On the transfer pipeline of water vapour, it is provided with the first control dress
It sets, to realize the switching and flow control of the connection disconnected state of water vapour, the first control device is by gate valve I 13
It is formed with restriction orifice I 15.On the transfer pipeline of high temperature carrier gas, it is also equipped with first control device, to realize high temperature carrier gas
Connection disconnected state switching and flow control, in the present embodiment, on high temperature carrier gas transfer pipeline first control
Device is regulating valve I 11.
3 front end hot gas cooler I of the invention is also connected with fluidized-bed reactor 2；The fluidized-bed reactor 2 with
It is equipped with second control device in the process gas transfer pipeline of the connection of hot gas cooler I 3, is electric gate valve I in the present embodiment
7, to control connection or not be connected to；2 front end of fluidized-bed reactor is connected with carrier gas preheater 1.
Hot-air filter I removes 5 rear end connection crystallizer；
In the present invention, high temperature carrier gas conveying mechanism 17 and fluidized-bed reactor 2 share a carrier gas source, the carrier gas source
Carrier gas by carrier gas preheater 1 heating after, be divided into two-way, all the way connect fluidized-bed reactor 2, all the way connect hot gas it is cooled
Filter unit.
Rotary back-blowing device I 19 is additionally provided in the present invention in hot-air filter I 5, for the mistake to hot-air filter I 5
Chimney filter carries out blowback.
The chemical regeneration system of hot gas cooler and/or hot-air filter in a kind of Melamine Production system of embodiment 4
System
The chemical regeneration system of hot gas cooler and/or hot-air filter in Melamine Production system as shown in Figure 2
System repeats embodiment 3, there is following difference：
Both the water vapour conveying mechanism 18 and the high temperature carrier gas conveying mechanism 17 are in advance in transfer pipeline
After converging, it is then connected to the front end of hot gas cooler I 3.Specifically, it is provided on the transfer pipeline of water vapour conveying mechanism 18
First control device (is made of gate valve I 13 and restriction orifice I 15) in the present embodiment, the water vapour conveying after gate valve I 13
On pipeline connection to high temperature carrier gas transfer pipeline, the two pipeline converges, and first control device is provided on the pipeline converged (at this
In embodiment 11) for regulating valve I, then it is connected to hot gas cooler I 3.
The chemical regeneration system of hot gas cooler and/or hot-air filter in a kind of Melamine Production system of embodiment 5
System
The chemical regeneration system of hot gas cooler and/or hot-air filter in Melamine Production system as shown in Figure 3
System repeats embodiment 4, there is following difference：
After the water vapour conveying mechanism and the high temperature converge in transfer pipeline in advance for both warm mechanisms,
It is divided into two-way, is connected to hot gas cooler front end all the way, another way is connected to hot-air filter front end.
A kind of Melamine Production of embodiment 6 and equipment regenerative system
Melamine Production and equipment regenerative system as shown in Figure 4, contains fluidized-bed reactor 2, fluidized-bed reactor 2
Two sets of hot gas cold filtration units in parallel, hot gas cold filtration unit series-connected crystallizers again.The first set hot gas is cooled
The hot-air filter I 5 that filter unit contains hot gas cooler I 3 and is attached thereto, second set of hot gas cold filtration unit contain heat
The Gas Cooler II 4 and hot-air filter II 6 being attached thereto.
In the parallel branch of hot gas cold filtration unit, between fluidized-bed reactor and hot gas cooler, it is equipped with the
Two control devices, in the present embodiment, the second control device in the first, second parallel branch are respectively 7 He of electric gate valve I
Electric gate valve II 8.
In the parallel branch of hot gas cold filtration unit, between hot-air filter and crystallizer, it is equipped with third and controls
Device, in the present embodiment, the third control device in the first, second parallel branch is respectively electric gate valve III 9 and electronic
Gate valve IV 10.
In the front end of hot gas cold air device, it is connected with water vapour conveying mechanism 18, to hot gas cold filtration unit transportation
Water vapour is also connected with high temperature for warm mechanism, and the high temperature is high temperature carrier gas conveying mechanism for warm mechanism in the present embodiment
17, to provide hot environment to every set hot gas cold filtration unit.
On the coconnected steam conveyor tube road of the first, second parallel branch, it is respectively equipped with first control device, at this
In embodiment, which is made of a restriction orifice and gate valve respectively, specifically, the first, second parallel branch
Coconnected steam conveyor tube is respectively equipped with restriction orifice I 15, II 16 and gate valve I 13, II 14.
On the coconnected high temperature carrier gas transfer pipeline of the first, second parallel branch, it is also respectively equipped with first control device,
In the present embodiment, the first control device of the coconnected high temperature carrier gas delivery pipe of the first, second parallel branch is respectively to adjust
Valve I 11 and regulating valve II 12.
In the present embodiment, two sets of hot gas cold filtration units shareds, one water vapour conveying mechanism, it is specifically, described
The delivery pipe of water vapour conveying mechanism is divided into two-way, is connected to the hot gas cooler I 3 of first set hot gas cold filtration unit all the way
Front end, another way be connected to second set of hot gas cold filtration unit thermally cooler II 4 front end.
In the present embodiment, two sets of hot cold filtration units shareds, one high temperature carrier gas conveying mechanism, it is specifically, described
The delivery pipe of high temperature carrier gas conveying mechanism is divided into two-way, is connected to the hot gas cooler I of first set hot gas cold filtration unit all the way
3 front end, another way are connected to the front end of the thermally cooler II 4 of second set of hot gas cold filtration unit.Further, it is connected to
Steam conveyor tube branch to hot gas cooler front end first converges with high temperature carrier gas delivery pipe branch two-by-two, then is connected respectively to
Hot gas cooler front end.As a preferred embodiment, in this embodiment, the water vapour and high temperature carrier gas after converging are defeated
Pipe is sent, the technique letter shoot being communicated between the hot gas cold air device and second control device of the set hot gas cold filtration unit,
At this point, water vapour has certain time and spatial mixing uniform with high temperature carrier gas, water vapor concentration can be prevented excessively high, reacted endless
Entirely, unreacted water vapour, which enters rear workshop section, influences the consumption of melamine, and regeneration gas can be prevented to be unevenly distributed and caused
Non-uniform phenomenon is regenerated to occur.
System of the invention also contains carrier gas preheater 1, and carrier gas preheater 1 is passed through fluidized-bed reactor after preheating carrier gas
2。
Further respectively had in hot-air filter in the first, second parallel branch of the invention rotary back-blowing device I 19,
II 20 carries out blowback for the screen pipe to hot-air filter I 5, II 6.
In the present invention, high temperature carrier gas conveying mechanism 17 and fluidized-bed reactor 2 share a carrier gas source, the carrier gas source
Carrier gas by carrier gas preheater 1 heating after, be divided into two-way, all the way connect fluidized-bed reactor 2, all the way connect hot gas it is cooled
Unit is filtered, the high temperature carrier gas delivery pipe for being connected to hot gas cold filtration unit is further divided into two-way, is connected respectively to hot gas cooler I
4 front end 3 and hot gas cooler II.
A kind of Melamine Production of embodiment 7 and equipment regenerative system
As shown in figure 5, repeating embodiment 6, there is following difference, be communicated to the steam conveyor tube of hot gas cooler front end
Branch does not converge two-by-two with high temperature carrier gas delivery pipe branch, but is respectively communicated with hot gas cooler front end.
The operation process of the Melamine Production of the invention of embodiment 8 and equipment regenerative system
By taking the Melamine Production of embodiment 6 and equipment regenerative system as an example.
As shown in figure 4, a kind of Melamine Production and equipment regenerative system, including fluidized-bed reactor 2, fluidized-bed reaction
Device 2 includes the feed inlet set on reactor bottom, for being passed through high temperature carrier gas.Carrier gas from Carrier Gas Compressor outlet, through carrying
After air preheater 1 is heated to 350~400 DEG C, fluidized-bed reactor 2 is entered by the feed inlet of 2 bottom of fluidized-bed reactor, it will be anti-
The catalyst in device is answered to be fluidized；Fusing urea is by entering fluidized-bed reactor 2 in the middle part of reactor, in fluidized-bed reactor 2
The middle urea that carries out generates the reaction of melamine, and has the side reaction of melamine deamination；Fused salt heating coil is located at anti-
Device lower part is answered, required heat is reacted for providing, maintains the temperature of the reactor in 350~400 DEG C, pressure 0.1
Between~0.7MPa；Discharge port is located at reactor head, and the reaction for generating in output-response device generates gas.
The reaction come out at the top of fluidized-bed reactor 2 generates gas, cold with 2 sets of hot gas into hot gas cold filtration unit
But for filter element：
1. normal operating condition
When the 1st set of hot gas cold filtration unit operates normally, import electric gate valve I 7 and outlet electric gate valve III 9
It is in the open state that (the 2nd set of hot gas cold filtration unit inlet electric gate valve II 8 is in close state at this time, exports electric brake
Valve IV 10 is in the open state)；
It is cold that the reaction generation conductance that gravity flow 2 discharge port temperature of fluidized bed reactor is 380~390 DEG C in the future enters the 1st set of hot gas
But filter element first enters back into heat after being cooled to 330~350 DEG C into hot gas cooler I 3 through its import electric gate valve I 7
Air filter I 5 is filtered to remove the by-product and catalyst fines carried secretly in gas；
From hot-air filter I 5 come out gas through electric gate valve III 9 decrystallize device crystallization.
2. the switching of hot gas cold filtration unit
When the resistance of the 1st set of hot gas cold filtration unit rises to 20KPa or more, need to switch over；
It is first turned on the 2nd set of hot gas cold filtration unit inlet electric gate valve II 8, outlet electric gate valve IV 10 has been located
In opening state；At this point, the 2nd set of hot gas cold filtration unit is in normal operating condition；
The 1st set of hot gas cold filtration unit inlet electric gate valve I 7 is progressively closed off, at this point, it exports electric gate valve III 9 still
It is so in the open state；
I 11 aperture of regulating valve on high temperature carrier gas conveying mechanism 17 is adjusted to 100%, while opening regulating valve II 12
Degree is adjusted to 10~20%, by containing in the hot gas cooler I 3 and hot-air filter I 5 in the 1st set of hot gas cold filtration unit
There is the process gas of melamine to be replaced, to prevent a large amount of melamine in gas to be decomposed, while guaranteeing that it regenerates institute
The high temperature carrier gas flux needed.
3. the chemical regeneration of hot gas cold filtration unit
The main valve on water vapour conveying mechanism 18 is opened, the steam condensate in pipeline is drained, until vapor (steam) temperature is greater than
150℃；
It opens water and steams gate valve I 13 on conveying mechanism 18, steam rates are controlled by restriction orifice I 15, by water vapour
High temperature carrier gas conveying mechanism 17 is introduced, enters hot gas cooler I 3 through regulating valve I 11 together with high temperature carrier gas；
In hot gas cooler I 3, it is catalyzed using the silica gel or Alusil or aluminium oxide that are adhered in heat transfer tube wall
Agent, water vapour react with the melamine being adhered on inside pipe wall, sweet primary amine, melem respectively and generate ammonia and carbon dioxide；
Water vapour comes out with high temperature carrier gas from hot gas cooler I 3, into hot-air filter I 5, in hot-air filter I 5
It is interior, make catalyst using the silica gel or Alusil or aluminium oxide that are adhered on filter bag outer wall, water vapour respectively be adhered to
Melamine, sweet primary amine on filter bag outer wall, melem reaction generate ammonia and carbon dioxide；
Ammonia and carbon dioxide gas caused by chemical regeneration come out together with high temperature carrier gas from hot-air filter I 5, warp
Electric gate valve III 9 is crossed, decrystallize device；
After regeneration 2~10 hours, gate valve I 13 and water vapour main valve on water vapour conveying mechanism 18 are closed, stops regeneration,
And I 11 aperture of regulating valve on high temperature carrier gas conveying mechanism 17 is adjusted to 10~20%；
Start the rotary back-blowing device I 19 on hot-air filter I 5, the screen pipe of hot-air filter I 5 is carried out anti-
It blows, after blowback carries out 1~3 wheel, starts the automatic removing dust program of hot-air filter I 5, carry out ash discharge；
It regenerates and the 1st set of hot gas cold filtration unit after ash discharge, resistance drops to 10KPa or so by 20KPa, be in
Hot stand-by duty can be switched use at any time.
Chemical regeneration method operation result is as shown in table 1.
The overall target of the chemical regeneration method of a kind of melamine hot gas cooler of table 1 and hot-air filter application front and back
Compare (in terms of producing 50000 tons of melamines per year by gas phase quenching process)
As shown in Table 1, the chemical regeneration method system and technique of hot gas cooler of the invention and hot-air filter, not only
It fundamentally solves the problems, such as that hot gas cooler and hot-air filter are susceptible to plugging, greatly prolongs making for hot-air filter filter bag
With the service life, and without cleaning, manpower and the decline of material resources cost, the excellent rate of product is promoted, in addition, reducing the pollution of dust, favorably
In environmental protection.
Claims (10)
1. a kind of for the hot gas cooler of Melamine Production and the chemical regeneration method of hot-air filter, which is characterized in that
The method is to be passed through water vapour to hot gas cooler and/or hot-air filter；And to hot gas cooler and/or hot gas filtration
At least its internal offer hot environment of device.
2. according to claim 1 for the hot gas cooler of Melamine Production and the chemical regeneration side of hot-air filter
Method, it is characterised in that by being passed through high temperature carrier gas to hot gas cooler and/or hot-air filter, to provide high temperature ring for its inside
Border；
Preferably, the hot environment or the temperature of high temperature carrier gas are at 300 DEG C or more, and preferably 300 DEG C~400 DEG C, more preferably
350 DEG C~400 DEG C；
Preferably, maintain the pressure of hot gas cooler and/or hot-air filter in 0.1~0.7MPa；
Preferably, in the hot gas cooler and/or hot-air filter, remain melamine before regeneration or in regenerative process
Generated by-product and used catalyst in amine synthesis, or optionally, also remain melamine；
Preferably, the melamine synthesizes low-pressure process melamine and generates technique；
Preferably, the by-product is one or both of close primary amine or Miller amine；
Preferably, the catalyst is at least one of silica gel, Alusil, aluminium oxide；
Preferably, the high temperature carrier gas is at least one of ammonia, carbon dioxide, nitrogen；It is highly preferred that the high temperature
Carrier gas is ammonia and carbon dioxide.
3. the equipment regeneration method during a kind of Melamine Production, during the Melamine Production, raw material is reacting
It is reacted in device through catalyst, generates gaseous melamine and by-product, gaseous melamine and by-product go out from reactor
Mouth output, and the hot gas cold filtration unit by being connected to reactor, by-product become solid-state in hot gas cold filtration unit
And it is trapped to separate with melamine, which is characterized in that the reactor parallel connection at least two sets of hot gas cold filtration units；
It includes the following steps：
1) during Melamine Production, at least a set of hot gas cold filtration unit be in can operating status, reactor first connects
It is logical can be a set of in the hot gas cold filtration unit of operating status, the set hot gas cold filtration unit is in operating status at this time,
The by-product escaped from reactor is retained, by-product is accumulated in the set hot gas cold filtration list becomes the cooled of load
Filter unit；
2) during continuous production, by the cold filtration unit of load described in step 1) from operating status switch to production from
Linear state；It is another set of in can operating status hot gas cold filtration unit be then switched to be connected to reactor in run shape
State, the production process for continuing to serve melamine is to retain by-product；
3) the hot gas cold filtration unit in production off-line state carries out again by before being switched to operating status next time
It is raw and become can operating status hot gas cold filtration unit；The regenerative process is：Water is passed through to hot gas cold filtration unit
Steam, and hot environment is provided to hot gas cold filtration unit.
4. the equipment regeneration method during Melamine Production according to claim 3, which is characterized in that hot gas is cooling
Device rear end is connected with hot-air filter front end becomes hot gas cold filtration unit；
Preferably, when the gaseous melamine and by-product are exported from reactor outlet, partial catalyst, hot gas are also taken out of
Cold filtration unit also while having retained catalyst when retaining by-product；
Preferably, a small amount of melamine is also remained in the hot gas cold filtration unit.
5. according to the method described in claim 4, it is characterized in that；In step 3), by being passed through to hot gas cold filtration unit
High temperature carrier gas, to provide hot environment for its inside；
Preferably, the hot environment or the temperature of high temperature carrier gas are at 300 DEG C or more；Preferably, 300 DEG C~400 DEG C；More
Preferably, 350 DEG C~400 DEG C；
Preferably, in step 3), after water vapour is mixed with high temperature carrier gas, then it is passed through hot gas cold filtration unit together；
Preferably, in step 3), maintain the pressure of hot gas cold filtration unit in 0.1~0.7MPa；
Preferably, the by-product is one or both of close primary amine or Miller amine；
Preferably, the catalyst is one of silica gel, Alusil, aluminium oxide at least one；
Preferably, in step 3), regenerative process occur chemical reaction generate product gas be ammonia and carbon dioxide, and from
It is removed in hot gas cold filtration unit；
Preferably, after chemical reaction, blowback also is carried out to the hot-air filter in hot gas cold filtration unit；Blowback is at least
After one wheel, ash discharge is carried out to hot-air filter；It is highly preferred that the blowback is rotary back-blowing；It is highly preferred that the blowback
For 1~3 wheel；
Preferably, in step 2), the hot gas cold filtration unit be in can operating status refer to the hot gas mistake in the unit
The pressure of filter is 20KPa or less；It is preferred that 15kPa or less；More preferable 10KPa；
Preferably, in step 2), when the resistance of the cold filtration unit of load rises to 20KPa or more, switch another set of
The operation of cold filtration unit；
Preferably, in step 3), when hot gas cold filtration unit drop in resistance at least 10KPa, regeneration ending；
Preferably, the high temperature carrier gas is at least one of ammonia and carbon dioxide, nitrogen；It is highly preferred that the height
Warm carrier gas is ammonia and carbon dioxide.
6. a kind of chemical regeneration system of equipment, the equipment is hot gas cooler and/or heat in Melamine Production system
Air filter；The regenerative system further includes：
Water vapour conveying mechanism, to convey water vapour into hot gas cooler and/or hot-air filter；
High temperature is for warm mechanism, to provide hot environment to hot gas cooler and/or hot-air filter.
7. the chemical regeneration system of equipment according to claim 6, which is characterized in that
The high temperature is carrier gas conveying mechanism for warm mechanism, to convey high temperature into hot gas cooler and/or hot-air filter
Carrier gas；
Preferably, the high temperature carrier gas is at least one of ammonia, carbon dioxide, nitrogen；It is highly preferred that the high temperature
Carrier gas is ammonia and carbon dioxide；
The temperature of the hot environment or high temperature carrier gas is at 300 DEG C or more；Preferably, 300 DEG C~400 DEG C；It is highly preferred that
350 DEG C~400 DEG C；
Preferably, hot gas cooler rear end is connected with hot-air filter front end becomes hot gas cold filtration unit；Described
Water vapour conveying mechanism and the high temperature are respectively connected to the front end of hot gas cold filtration unit for warm mechanism；Alternatively, described
Water vapour conveying mechanism and after the high temperature converges in transfer pipeline in advance for both warm mechanisms, it is cold to be then connected to hot gas
But the front end of filter element；
Alternatively, the water vapour conveying mechanism and/or high temperature separate two line branchings, the connection heat for warm mechanism
Gas Cooler, a connection hot-air filter；Or the water vapour conveying mechanism and/or high temperature is separated for warm mechanism
After two line branchings, the elder generation of branch on steam conveyor tube road and high temperature converge for the transfer pipeline branch of warm mechanism, then distinguish
Connection the hot gas cooler and hot-air filter；
Preferably, the water vapour conveying mechanism, high temperature contain shared or independent conveyance conduit for warm mechanism, and pass through
First control device on conveyance conduit is connect with the hot gas cold filtration unit, thus realize connected state with not
The switching of connected state；
Preferably, the front end of the hot gas cooler is also connected with melamine reactor；
Preferably, the hot-air filter rear end is also connected with crystallizer；The melamine reactor and hot gas is cooling
It is equipped with second control device in the reactant gas delivery path road of device connection, to control connection or not be connected to；
Also, the pipeline of the first control device front end of the conveyance conduit is filled with the second control in process gas transfer pipeline
The pipeline of front end is set, the two is independent tubes；And the pipeline of their rear end, the two are independent pipeline or merge shared pipe
Road.
8. a kind of Melamine Production and equipment regenerative system, which is characterized in that contain two sets or more of hot gas in the system
Cold filtration unit further includes the reactor before being connected to hot gas cold filtration unit, and is connected to hot gas cold filtration
Crystallizer after unit；
Every set hot gas cold filtration unit of the system is connected with：
Water vapour conveying mechanism, to convey water vapour into the hot gas cold filtration unit of every set parallel connection；
High temperature is for warm mechanism, to provide hot environment to the hot gas cold filtration unit of every set parallel connection.
9. Melamine Production according to claim 8 and equipment regenerative system, which is characterized in that
The high temperature is carrier gas conveying mechanism for warm mechanism, to convey high temperature into the hot gas cold filtration unit of every set parallel connection
Carrier gas；
Preferably, the high temperature carrier gas is at least one of ammonia, carbon dioxide, nitrogen；It is highly preferred that the high temperature
Carrier gas is ammonia and carbon dioxide；
Hot environment or the temperature of high temperature carrier gas are at 300 DEG C or more；Preferably, 300 DEG C~400 DEG C；It is highly preferred that 350 DEG C
~400 DEG C；
Preferably, hot gas cooler rear end is connected with hot-air filter front end becomes hot gas cold filtration unit；Described
Water vapour conveying mechanism and the high temperature are respectively connected to the front end of hot gas cold filtration unit for warm mechanism；Alternatively, described
Water vapour conveying mechanism and after the high temperature converges in transfer pipeline in advance two-by-two for warm mechanism, it is cold to be then connected to hot gas
But the front end of filter element；
Alternatively, the water vapour conveying mechanism and/or high temperature separate two line branchings, the connection heat for warm mechanism
Gas Cooler, a connection hot-air filter；Or the water vapour conveying mechanism and/or high temperature is separated for warm mechanism
After two line branchings, the elder generation of branch of vapor transfer pipeline and high temperature converge for the transfer pipeline branch of warm mechanism, then distinguish
Connection the hot gas cooler and hot-air filter.
10. system according to claim 9, which is characterized in that
The water vapour conveying mechanism, high temperature contain shared or independent conveyance conduit for warm mechanism, and defeated by being located at
The first control device on pipeline is sent to connect with the hot gas cold filtration unit, to realize connected state and not connected state
The switching of state；
Second control device is equipped in the process gas transfer pipeline that the melamine reactor is connect with hot gas cooler, from
And it controls connection or is not connected to；
Also, the pipeline of the first control device front end of the conveyance conduit is filled with the second control in process gas transfer pipeline
The pipeline of front end is set, the two is independent tubes；And the pipeline of their rear end, the two are independent pipeline or merge shared pipe
Road；
Preferably, third control device is equipped in the process gas transfer pipeline that the hot-air filter is connect with crystallizer, from
And it controls connection or is not connected to；
Preferably, the second control device and third control device are electric gate valve；
Preferably, the hot gas cold filtration unit of every set parallel connection is separately connected a water vapour conveying mechanism and a high temperature for temperature
Mechanism；Alternatively, the hot gas cold filtration unit of every set parallel connection connects a water vapour conveying mechanism and a high temperature for temperature jointly
Mechanism, wherein the steam conveyor tube conveying mechanism/high temperature is cooled down for the delivery pipe of warm mechanism according to hot gas in parallel
The tricks of filter element is divided into the high temperature of respective numbers for warm mechanism delivery pipe branch group/steam conveyor tube branch group, respectively
It is connected to hot gas cold filtration unit front end；Alternatively, the steam conveyor tube branch group and the high temperature are for warm mechanism
Delivery pipe branch group after first converging two-by-two, then is connected to every set hot gas cold filtration unit front end one by one；
Alternatively, each branch group of the steam conveyor tube conveying mechanism/high temperature for warm mechanism, is further divided into two fractions
Branch, two secondary branch of the steam conveyor tube conveying mechanism are connected respectively to hot gas cooler leading portion and hot gas filtration
Device front end, the high temperature are also connected to hot gas cooler leading portion and hot gas for two secondary branch of warm mechanism delivery pipe
Filter front；Or the steam conveyor tube conveying mechanism and high temperature be for the secondary branch of warm mechanism, after converging two-by-two,
It is connected to the front end of hot gas cooler and hot-air filter；
Preferably, on the conveyance conduit/or pipe branch of the water vapour conveying mechanism of every set hot gas cold filtration unit connection
First control device contains restriction orifice and gate valve；Preferably, the first control device is successively set along water vapor stream to direction
Current limiting orifice plate and gate valve, alternatively, being successively arranged gate valve and restriction orifice.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710326146.9A CN108871027B (en) | 2017-05-10 | 2017-05-10 | Chemical regeneration method and system for melamine hot gas cooler and hot gas filter |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710326146.9A CN108871027B (en) | 2017-05-10 | 2017-05-10 | Chemical regeneration method and system for melamine hot gas cooler and hot gas filter |
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| CN108871027B CN108871027B (en) | 2020-08-14 |
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030004343A1 (en) * | 1999-10-05 | 2003-01-02 | Tjioe Tjay T. | Process for the preparation of melamine |
| CN1835932A (en) * | 2004-01-17 | 2006-09-20 | 卡萨尔化学股份有限公司 | Process for the gentle cooling and crystallisation of melamin from a melamin melt or from the liquid phase |
| CN103102320A (en) * | 2013-01-17 | 2013-05-15 | 李鑫 | Production method of melamine by slow cooling crystallization |
-
2017
- 2017-05-10 CN CN201710326146.9A patent/CN108871027B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030004343A1 (en) * | 1999-10-05 | 2003-01-02 | Tjioe Tjay T. | Process for the preparation of melamine |
| CN1835932A (en) * | 2004-01-17 | 2006-09-20 | 卡萨尔化学股份有限公司 | Process for the gentle cooling and crystallisation of melamin from a melamin melt or from the liquid phase |
| CN103102320A (en) * | 2013-01-17 | 2013-05-15 | 李鑫 | Production method of melamine by slow cooling crystallization |
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|---|---|
| CN108871027B (en) | 2020-08-14 |
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