CN105399455B - A kind of system and method using chemical industry tail gas production compound fertilizer - Google Patents

Abstract

The invention discloses a kind of system and methods using chemical industry tail gas production compound fertilizer, which includes sequentially connected ammonia evaporation element, ammonium nitrate solution preparation unit and nitro-compound fertilizer preparation unit；The ammonia evaporation element mainly includes sequentially connected liquefied ammonia surge tank, gas ammonia filter and gas ammonia superheater；The ammonium nitrate solution preparation unit mainly includes sequentially connected tubular reactor, neutralizes flash tank and vaporising device；The nitro-compound fertilizer preparation unit is high-tower granulation device；Gas ammonia superheater in the ammonia evaporation element is connect with the tubular reactor in the ammonium nitrate solution preparation unit, and the vaporising device in the ammonium nitrate solution preparation unit is connect with the high-tower granulation device in the nitro-compound fertilizer preparation unit；Melamine tail gas is prepared into ammonium nitrate solution by the filtering of ammonia evaporation element, heating, subsequently into ammonium nitrate solution preparation unit and nitric acid, finally enters nitro-compound fertilizer preparation unit and is prepared into nitro-compound fertilizer.

Description

A kind of system and method using chemical industry tail gas production compound fertilizer

Technical field

The present invention relates to melamine tail gas comprehensive utilizations and nitro-compound fertilizer production field, more particularly to production ammonium nitrate With the system and method for nitro-compound fertilizer.

Background technique

Currently, domestic urea production capacity is seriously superfluous, melamine becomes the selection for developing urea downstream product, but trimerization Cyanamide vent gas treatment becomes the matter of utmost importance of melamine plant development.Melamine tail gas returns carbamide production system and increases urine Plain middle low-pressure system load, production ammonium hydrogen carbonate economic benefit is bad, produces soda ash and ammonium chloride complementary conditions require height.

There is advanced and mature production technology on nitro-compound fertilizer both at home and abroad.External technology substantially uses air-flow Phosphate fertilizer or potash fertilizer are sent in the ammonium nitrate phosphorus melting liquid bath for being granulated tower top by conveying equipment, are melted by stirring, are made into granulation tower Grain forms granular complex fertilizer product, but external technology transfer expense is relatively high.The country uses part slurry process production technology Simply, but take up a large area, long flow path, rotating machinery is more, power consumption is big, ammonia evolution rate is higher, operating environment is poor；Pellet granulation Production technology is granulated balling ratio generally between 35%-60%, should not produce the compound fertilizer of high nitrogen kind, and general (N) is not more than 18%, than high, returning charge amount is 2.5 times or so of product for the technique returning charge；High-tower granulation technique is in ammonium nitrate phosphorus, ammonium nitrate, nitric acid It is widely used in the production of phosphate fertilizer, then just starts to be related in nitro compound fertilizer production.

Usual melamine tail gas is used for urea production, when producing urea with melamine tail gas, is easy to cause urea raw The pressure instability of production. art, to influence the production of urea.

Summary of the invention

In order to play triamine tail gas value while produce nitro-compound fertilizer product, the present invention, which provides, a kind of utilizes melamine Tail gas and nitric acid prepare ammonium nitrate, then the system with " high-tower granulation " technique coproduction nitro-compound fertilizer.The present invention also provides one kind Utilize the method for chemical industry tail gas production compound fertilizer.

To achieve the above object, the technical solution of the present invention is as follows:

A kind of system using chemical industry tail gas production compound fertilizer, including sequentially connected ammonia evaporation element, ammonium nitrate solution system Standby unit and nitro-compound fertilizer preparation unit；

The ammonia evaporation element mainly includes sequentially connected liquefied ammonia surge tank, gas ammonia filter and gas ammonia superheater；

The ammonium nitrate solution preparation unit mainly includes sequentially connected tubular reactor, neutralizes flash tank and evaporation dress It sets；

The nitro-compound fertilizer preparation unit is high-tower granulation device；

Gas ammonia superheater in the ammonia evaporation element is connect with the tubular reactor in the ammonium nitrate solution preparation unit, Vaporising device in the ammonium nitrate solution preparation unit is connect with the high-tower granulation device in the nitro-compound fertilizer preparation unit；

Melamine tail gas is by the filtering of ammonia evaporation element, heating, subsequently into ammonium nitrate solution preparation unit and nitric acid system For at ammonium nitrate solution, finally enters nitro-compound fertilizer preparation unit and be prepared into nitro-compound fertilizer.

The melamine tail gas pressure into system can be stablized in liquefied ammonia surge tank, it is molten with nitric acid in tubular reactor Liquid carries out countercurrent reaction, not only reduces the reaction time of melamine tail gas and nitric acid, and being capable of pressure in systems stabilisation Power, neutralize flash tank by tail gas remaining after reaction neutralization steam, with further systems stabilisation pressure, then through pervaporation, make Grain becomes nitro-compound fertilizer, ensure that melamine tail gas was produced within the system by the collective effect of above-mentioned apparatus Pressure stability, to ensure that melamine tail gas recycles the production with nitro-compound fertilizer.

Using tubular reactor, so that melamine tail gas and the unit volume production capacity of nitric acid improve, to improve The conversion ratio of melamine tail gas, the ammonium nitrate solution of preparation realize three-waste free discharge, cleaning life by high-tower granulation device It produces, reduce energy consumption, improve the yield of nitro-compound fertilizer, while ensure that the efficient utilization of melamine tail gas, reduce life Produce cost.

Preferably, the import of the liquefied ammonia surge tank connects liquid ammonia ball tank.When melamine tail gas is unsatisfactory for production, energy Enough liquefied ammonia continues to produce.

It is further preferred that the import of the liquefied ammonia outlet connection liquid ammonia evaporator of the liquefied ammonia surge tank, the liquefied ammonia are slow The waste for rushing tank connects the import of discharge evaporator, the gas ammonia of the liquid ammonia evaporator with the waste of liquid ammonia evaporator The outlet of the gas ammonia of outlet and discharge evaporator is connect with the import of liquefied ammonia surge tank, and the waste of the discharge evaporator connects Connect sewage disposal system.It can be improved the utilization efficiency of liquefied ammonia.

Preferably, the vaporising device is sequentially connected just flash vaporization slot, first evaporator and whole evaporator, wherein The just flash vaporization slot is connect with the neutralization flash tank, and the end evaporator is connect with the high-tower granulation device.Just steam Hair flash tank avoids enter into evaporator and causes evaporator pressure excessive and influence production for steaming the ammonia etc. carried secretly in solution System is stablized.First evaporator is used for initial concentration liquid, evaporates most moisture, provides the intermediate product of higher concentration, both The ingredient of available part external application.Whole evaporator is used for further concentrated liquid, reaches high concentration melt liquid.First evaporator With whole evaporator use in conjunction, thermal energy can be made full use of to be concentrated by evaporation, convenient for controlling evaporator process constant respectively, improve and steam The efficiency and effect of hair.

It is further preferred that the waste vapour outlet of the end evaporator is connected with the import of vapor seperator, the evaporation eventually The taphole of device is connect with the high-tower granulation device.The waste vapour generated to whole evaporator utilizes, and improves waste vapour and utilizes, Reduce the discharge of waste.

Still more preferably, the import of the vapor seperator is connected with the outlet of the waste vapour of first evaporator, described just to steam The taphole for sending out device is connected with the import of whole evaporator.The waste vapour generated to first evaporator utilizes, and improves waste vapour and utilizes, Reduce the discharge of waste.

Preferably, the ammonium nitrate solution preparation unit is connect with washing unit is neutralized；The neutralization washing unit is successively The humidifier and steaming tower of connection, the humidifier import are connected with the neutralization flash tank gas vent, the neutralization Flash tank liquid outlet is connected with vaporising device, and the steaming tower outlet is connected with steam pipe network.It can be to being pressed from both sides in steam Miscellaneous ammonia and ammonium nitrate is recycled, and improves the yield of raw material, while improving waste vapour utilization, reduces the discharge of waste.

It is further preferred that the steaming tower liquid outlet is connect with the neutralization flash tank import, the steam Scrubbing tower gas vent is connected with steam pipe network.The ammonium nitrate solution that recycling generates when neutralizing is reduced with improving the utilization rate of raw material Production cost.

A method of compound fertilizer being produced using chemical industry tail gas, the steps include:

1) melamine tail gas enters reactor after passing sequentially through filtering, heat treatment；

2) melamine tail gas that treated generates ammonium nitrate solution with nitric acid pressurization neutralization reaction in the reactor, will give birth to At ammonium nitrate solution be concentrated by evaporation, the neutralized washing removing of the steam of generation；

3) ammonium nitrate solution after being concentrated is prepared into nitro-compound fertilizer using high tower fused melt granulated technique.

Preferably, it when melamine deficiency, is generated, be the steps include: using liquefied ammonia

1) liquefied ammonia enters reactor after passing sequentially through filtering, heat treatment；

2) neutralization reaction of pressurizeing in the reactor with nitric acid of liquefied ammonia generates ammonium nitrate solution after handling, by the nitric acid of generation The molten evaporation and concentration of ammonium, the neutralized washing of the steam of generation remove；

3) ammonium nitrate solution after being concentrated is prepared into nitro-compound fertilizer using high tower fused melt granulated technique.

The specific steps are that:

1. liquefied ammonia enters liquid ammonia evaporator under the effect of gravity in liquefied ammonia surge tank, changed with the recirculated water in tubulation Thermal evaporation goes out gas ammonia, and gas ammonia enters back into gas ammonia filter (except impurity such as degreasings) back to liquefied ammonia surge tank, further passes through Low-pressure saturated steam heating (110-120 DEG C) enters tubular reactor afterwards between gas ammonia superheater tubulation pipe；Liquefied ammonia surge tank, ammonia steam It sends out device bottom water and greasy dirt and is discharged to discharge evaporator low-pressure steam heating evaporation through blow-off line, the gas ammonia evaporated returns to Liquefied ammonia surge tank, residue drain into underground sewer through blowdown drum, enter back into treatment center of sewage and are handled；

2. in tubular reactor, nitric acid (58-60%) and purification heating after gas ammonia counter current contacting (0.4-0.5MPa, 175-180 DEG C) reaction generation ammonium nitrate, neutralized flash tank steams after dodging obtains ammonium nitrate solution (≤75%)；Ammonium nitrate solution (≤ 75%) successively by ammonium nitrate medial launder, first flash vaporization slot, first evaporator and whole evaporator, be concentrated to get 99% ammonium nitrate it is molten Liquid；Waste vapour caused by first evaporator and whole evaporator is discharged into vapor seperator from top and condenses and separates, and condenses out Boiled off liquor can be used for evaporating liquefied ammonia heat source；Technique caused by neutralization flash tank, first flash vaporization slot and vapor seperator is steamed Vapour is discharged from top, into scrubbing tower；

3. process steam initially enters humidifier (being Venturi scrubber), the technique superheated steam of scrubbing tower will be entered (185 DEG C when 175 DEG C or so/gas ammonia produces when triamine End gas production) drops to (138.35 DEG C) of saturation temperature and cools down and carry out prewashing It washs, maintains to recycle by detergent circulator, nitric acid needed for supplement is reacted is added in cleaning solution, ammonia is absorbed and neutralized；

4. 99% ammonium nitrate solution, which is metered into, is granulated tower top mixing channel, with the powdery monoammonium phosphate, white for being promoted to tower top The mixing of the solid materials moment such as marble, potassium sulfate, the low temperature eutectic slurry being mixed to form is whitewashed in top of tower, by difference Dynamic rotary pelleting machine is granulated, natural cooling balling-up obtains compound fertilizer granules in tower, is sent after being collected by the collection hopper of tower bottom to powder It flows cooler and carries out secondary cooling, the compound fertilizer granules after being fully cooled are packaged into after sieving and surface anti-caking is handled For finished product compound fertilizer.

Differential two-speed rotary granulating machine is made of two sets of independent transmission mechanisms and feeding system and electrical equipment control, each Transmission mechanism to its revolving speed and turns to the stepless control of progress, Liang Tao mechanism differential work on same axle center by corresponding variable-frequency power sources Make (can also synchronize), it is a set of to be responsible for for the highly viscous composite molten liquid with solid phase particles being averagely allocated to the differential rotation of granulation Each spray orifice of prilling spry, it is another set of, it is responsible for projecting molten liquid out of differential rotating granulation spray head, the molten liquid of injection Meet the spheric granules that air drag fracture is shrunk to certain diameter range.Highly viscous molten liquid, which easily blocks, is granulated differential rotation The spray orifice of prilling spry, thus be granulated differential rotating granulation spray head spray orifice can only as far as possible it is big could the long period be blocked with Meet quantity-produced requirement, big spray orifice must also can produce the spheric granules of the certain diameter range of technique requirement.It is differential Being granulated unique granulation principle can enable the fluid column projected from D diameter spray orifice be fractured into the particle of D/2 sphere diameter, and common granulation side Rule cannot accomplish this point.

Beneficial effects of the present invention:

(1) the difficult environmental issue of triamine tail gas is solved, while tail gas is recycled, and using energy source is improved Rate.

(2) high-tower granulation technique is advanced, and single machine Forced Mixing, mixture homogeneity is good, does not glue equipment.

(3) granulation tower is furnished with multistage cooling device, it is ensured that product does not agglomerate, and keeps loose.

(4) device is furnished with nitro compound fertilizer dry method device for recovering powder, and recycling powder can be used as factory, compound fertilizer raw material.

(5) melt pelletization takes full advantage of heat caused by ammonium nitrate molten liquid, and blend melt moisture content is low, without dry Dry process, saves mass energy；

(6) nitro azophoska compound fertilizer of high nitrogen, high concentration can be produced, product particle surface is smooth, and qualification rate is high, Prevented from caking, the market competitiveness is strong；

(7) three-waste free discharge.

Detailed description of the invention

Fig. 1 is system structure diagram of the invention；

Fig. 2 is ammonia evaporation element flow chart；

Fig. 3 is ammonium nitrate solution preparation unit flow chart；

Fig. 4 is to neutralize washing unit flow chart；

Fig. 5 is nitro-compound fertilizer preparation unit process；

Fig. 6 is ammonium nitrate solution concentration technology flow diagram；

Fig. 7 is nitro-compound fertilizer end evaporization process process flow chart；

Fig. 8 is that nitro-compound fertilizer solid material conveys process flow chart；

Fig. 9, which is that the screening of nitro-compound fertilizer finished product is cold, removes procedure technology flow chart；

Figure 10 is nitro-compound fertilizer packaging process process flow chart；

Wherein, I, ammonia evaporation element, II, ammonium nitrate solution preparation unit, III, nitro-compound fertilizer preparation unit, IV, neutralize wash Wash unit, 1, liquefied ammonia surge tank, 2, liquid ammonia evaporator, 3, gas ammonia filter, 4, discharge evaporator, 5, gas ammonia superheater, 6, pipe Formula reactor, 7 blowdown drums, 8, liquid ammonia ball tank, 9, neutralize flash tank, 10, ammonium nitrate pans, 11, first flash vaporization slot, 12, just Evaporator, 13, whole evaporator, 14,99% ammonium nitrate solution slot, 15, vapor seperator, 16, evaporative condenser liquid bath, 17, steam washes Wash tower, 18, proportioning belt, 19, mixing channel, 20, granulation tower, 21, powder flow cooler, 22, first vapor seperator, 23, just steaming Feel cold condenser, 24,92% ammonium nitrate solution slot, 25, raw material storage, 26, feed opening, 27, belt conveyor, 28, crusher, and 29, One elevator, 30 vibrating screens, 31, raw material feed bin, 32, measuring belt, the 33, second elevator, 34, third elevator, 35, returning charge Feed bin, the 36, first belt, the 37, second belt, the 38, the 4th elevator, 39, third belt, 40, level-one rotary screen, the 41, the 5th Elevator, 42, two stage cylinder sieve, 43, coating roller, the 44, the 6th elevator, 45, finished room, the 46, first baling line, 47, Second baling line, 48, finished product storehouse.

Specific embodiment

As shown in Figure 1, a kind of system using chemical industry tail gas production compound fertilizer, including sequentially connected ammonia evaporation element I, Ammonium nitrate solution preparation unit II and nitro-compound fertilizer preparation unit III, nitro-compound fertilizer preparation unit III and neutralization washing unit IV Connection；

As shown in Fig. 2, ammonia evaporation element I mainly includes sequentially connected liquefied ammonia surge tank 1, gas ammonia filter 3 and gas ammonia Superheater 5；The import of liquefied ammonia surge tank 1 connects liquid ammonia ball tank 8, and the import of liquefied ammonia surge tank 1 connects liquid ammonia evaporator 2, liquefied ammonia Surge tank 1 connects discharge evaporator 4 with the outlet of liquid ammonia evaporator 2, and the outlet of discharge evaporator 4 is separately connected liquefied ammonia surge tank 1 and blowdown drum 7, gas ammonia superheater 5 connects tubular reactor 6.

As shown in figure 3, ammonium nitrate solution preparation unit II mainly includes sequentially connected tubular reactor 6, neutralizes flash tank 9, ammonium nitrate medial launder 10 and vaporising device；Vaporising device is sequentially connected just flash vaporization slot 11, first evaporator 12 and steams eventually Send out device 13, whole evaporator 13 is separately connected 99% ammonium nitrate solution slot 14 and vapor seperator 15, vapor seperator 15 respectively with First evaporator 12 is connected with evaporative condenser liquid bath 16.

As shown in figure 5, nitro-compound fertilizer preparation unit III is high-tower granulation device, it mainly include sequentially connected 99% nitre Ammonium salt solution slot 14, mixing channel 19, granulation tower 20 and powder flow cooler 21, ingredient are delivered to mixing channel by proportioning belt 18 19。

As shown in figure 4, neutralizing washing unit IV is sequentially connected humidifier and steaming tower 17, steaming tower 17 It is connect with flash tank 9 is neutralized.

Detailed process using melamine tail gas production nitro-compound fertilizer is:

1. melamine tail gas recycling and ammonium nitrate solution preparation

As shown in Fig. 2, melamine tail gas pass sequentially through liquefied ammonia surge tank 1, gas ammonia filter 3 and gas ammonia superheater 5 into Enter to ammonium nitrate solution preparation unit II；Then it pressurizes in tubular reactor 6 with the dust technology (58-60%) from nitric acid plant Neutralize and generate ammonium nitrate solution, the neutralized flash distillation of flash tank 9 of the ammonium nitrate solution of generation obtains concentration ammonium nitrate solution (≤75%), nitre Ammonium salt solution (≤75%) pumped to ammonium nitrate medial launder 10 and first flash vaporization slot 11, generated process steam is dodged from first evaporation It steams 11 top row of slot to go out to neutralize washing unit IV, as shown in Figure 3.

2. ammonia evaporates

When melamine tail gas is not able to satisfy production, from garden, synthetic ammonia installation draws liquefied ammonia and is produced.

As shown in Fig. 2, the liquefied ammonia from liquid ammonia ball tank 8 enters liquefied ammonia surge tank 1, liquefied ammonia is in weight in liquefied ammonia surge tank 1 It is entered under the action of power liquid ammonia evaporator 2 (between tubulation), what the recirculated water heat exchange in the liquefied ammonia and tubulation between tubulation evaporated Gas ammonia again returns to liquefied ammonia surge tank 1, and the gas ammonia of liquefied ammonia surge tank 1 enters gas ammonia filter 3 except impurity such as degreasings out, passes through The gas ammonia of filter enters in gas ammonia superheater tubulation, is heated to 110-120 DEG C through the low-pressure saturated steam between tubulation and goes ammonium nitrate solution Preparation system.Liquefied ammonia surge tank 1,2 bottom water of liquid ammonia evaporator and greasy dirt are discharged to discharge evaporator 4 through blow-off line and are steamed with low pressure Vapour heating evaporation, the gas ammonia evaporated return to liquefied ammonia surge tank 1, and residue drains into underground sewer through blowdown drum 7, then It is handled into treatment center of sewage.

In 3. and wash

As shown in figure 3, the process steam (including indifferent gas in tail gas) for coming 9 top of self-neutralization flash tank enters steaming Tower 17, to recycle the ammonium nitrate and free ammonia that neutralize and carry secretly in steam.

Process steam containing ammonia and ammonium nitrate initially enters humidifier (being Venturi scrubber), will enter steaming tower 17 technique superheated steam (185 DEG C when 175 DEG C or so/gas ammonia produces when triamine End gas production) drops to saturation temperature (138.35 DEG C) cool down and pre-washed, maintain to recycle by detergent circulator, be added in cleaning solution nitric acid needed for supplement is reacted by ammonia into Row is absorbed and is neutralized.

The process steam being saturated after humidifier washs is entered by tower bottom distributor to be continued to wash in tower, cleaning solution Circulation is maintained by pump.By Gravity Separation to tower bottom, cleaning solution returns in scrubbing tower ammonium nitrate drop, during extra cleaning solution returns to With flash tank 9.Through in the washed secondary steam of bubble cap plate still contain micro ammonium nitrate, using high efficiency demister again into Row high purification guarantees that ammonia and ammonium nitrate therein is not exceeded, and the clean secondary steam after demisting is sent to steam pipe network.

4. solution is concentrated

As shown in fig. 6, entering ammonium nitrate solution (≤75% in first evaporator 12 from first flash vaporization slot 11) and from dirt Ammonium nitrate solution mixing after water process, mixed nitrate ammonium salt solution are flowed into just evaporator 12 under the action of from gravity, steam along first Hair 12 tubulation inner tubal wall of device forms a film naturally, is evaporated come the moisture content in heating evaporation ammonium nitrate solution by one section between pipe with steam It to 92% ammonium nitrate solution, send to 92% ammonium nitrate solution slot 24, is concentrated to get 99% again pumped to whole evaporator 13 Ammonium nitrate solution, send to 99% ammonium nitrate solution slot 14.Waste vapour caused by first evaporator 12 enter the separation of first vapor seperator 22, First evaporative condenser 23 is cooling, and the boiled off liquor condensed out enters evaporative condenser liquid bath 16.To sum up, ammonium nitrate solution (≤75%) Ammonium nitrate solution through first evaporator and the whole final generation 92% and 99% of evaporator evaporation, participates in ingredient.

Whole evaporization process is as shown in fig. 7,92% ammonium nitrate solution from first evaporator 12 is sent to 92% ammonium nitrate solution slot 24, it is sent in whole evaporator 13 by 92% ammonium nitrate solution slot 24, is reached by the ammonium nitrate solution concentration after the evaporation of whole evaporator 13 99% is sent to mixing channel 19 after 99% ammonium nitrate solution slot 14 produces compound fertilizer.

5. nitro-compound fertilizer process flow

As shown in figure 5, being sent by the ammonium nitrate solution that ammonium nitrate process is sent to 99% ammonium nitrate solution slot 14, pumped through ammonium nitrate solution It is metered into mixing channel 19 to 20 tower top of granulation tower, with powdery monoammonium phosphate, the white clouds for being promoted to tower top through proportioning belt 18 The mixing of the solid materials moment such as stone, potassium sulfate, the low temperature eutectic slurry being mixed to form are whitewashed in 20 top of tower of granulation tower It is granulated, by carrying out natural cooling in tower, send after the compound fertilizer granules of cooling balling-up are collected by the collection hopper of tower bottom to powder Body stream cooler 21 carries out secondary cooling, and the compound fertilizer granules after being fully cooled are after sieving and surface anti-caking is handled, through wrapping It dresses up as finished product compound fertilizer.

Solid material conveying operation as shown in figure 8, according to formula instruction by each monoammonium phosphate, potassium sulfate, dolomite dust, from 25 outbound of raw material storage transports to each related raw material feed opening 26 with forklift, and each feed opening 26 is dosed into after manually unpacking, by meter Amount is transported to mixing belt conveyor 27, is promoted through the first elevator 29 to vibrating screen 30 and is sieved after 28 coarse crushing of crusher Point, the bulk raw sifted out returns to the rough and torn progress of crusher 28 and is crushed, is promoted again, meet fineness requirement by pipeline to Raw material feed bin 31 is transported to upper tower elevator 33 through measuring belt 32, is delivered to mixing channel 19, is then delivered to granulation tower 20.

Finished product screening cooling process is as shown in figure 9, the compound fertilizer granules that tower bottom is sent out are transported to out the first belt of tower 37, so After be transported to finished product elevator 38, by finished product elevator 38 outlet be transported to the second belt 39, be then delivered to level-one rotary screen 40 are once sieved, and that sifts out does not meet the returning charge of granularity requirements, are transported to return conveyer 36, are conveyed by return conveyer 36 It is promoted by the second elevator 34 to mixing channel 19, is granulated again as material by metering to returning charge feed bin 35.

The finished product for meeting granularity requirements gone out through 40 level-one sub-sieve of level-one rotary screen is promoted by third elevator 41 to powder Stream cooler 21 is cooled down, and then carries out second level screening in two stage cylinder sieve 42, the returning charge that second level is sifted out is defeated by belt It send machine to be transported on the return conveyer 36 of level-one screening, returning charge feed bin 35 is transported to together with the returning charge that level-one is sifted out.It is logical The qualified finished product for crossing second level screening wraps up anticaking agent by metering, coating roller 43, is then delivered to subsequent processing packaging hilllock Position.

Packaging process is as shown in Figure 10, and coating compound fertilizer finished product is transported to the 4th elevator 44, is promoted and arrives finished product bin 45, at Product feed bin 45 designs two feed openings, and two fully-automatic packaging line the first baling lines 46 and the second baling line 47 is divided to be packaged into Bagged product.Then bagged product finished product storehouse 48 is transported to by belt conveyor to ship.

Above-mentioned, although the foregoing specific embodiments of the present invention is described with reference to the accompanying drawings, not to invention protection scope Limitation, those skilled in the art should understand that, based on the technical solutions of the present invention, those skilled in the art are not required to It is still within the scope of the present invention to make the creative labor the various modifications or changes that can be made.

Claims (10)

1. a kind of system using chemical industry tail gas production compound fertilizer, characterized in that including sequentially connected ammonia evaporation element, ammonium nitrate Solution preparation unit and nitro-compound fertilizer preparation unit；

The ammonia evaporation element mainly includes sequentially connected liquefied ammonia surge tank, gas ammonia filter and gas ammonia superheater；

The ammonium nitrate solution preparation unit mainly includes sequentially connected tubular reactor, neutralizes flash tank and vaporising device；

The nitro-compound fertilizer preparation unit is high-tower granulation device；

Gas ammonia superheater in the ammonia evaporation element is connect with the tubular reactor in the ammonium nitrate solution preparation unit, described Vaporising device in ammonium nitrate solution preparation unit is connect with the high-tower granulation device in the nitro-compound fertilizer preparation unit；

Melamine tail gas is prepared into subsequently into ammonium nitrate solution preparation unit with nitric acid by the filtering of ammonia evaporation element, heating Ammonium nitrate solution finally enters nitro-compound fertilizer preparation unit and is prepared into nitro-compound fertilizer.

2. a kind of system using chemical industry tail gas production compound fertilizer as described in claim 1, characterized in that the liquefied ammonia buffering The import of tank connects liquid ammonia ball tank.

3. a kind of system using chemical industry tail gas production compound fertilizer as claimed in claim 2, characterized in that the liquefied ammonia buffering The import of the liquefied ammonia outlet connection liquid ammonia evaporator of tank, the blowdown of the waste and liquid ammonia evaporator of the liquefied ammonia surge tank go out The import of mouthful connection discharge evaporator, the gas ammonia outlet of the liquid ammonia evaporator and the gas ammonia of discharge evaporator export and liquefied ammonia The import of surge tank connects, and the waste of the discharge evaporator connects sewage disposal system.

4. a kind of system using chemical industry tail gas production compound fertilizer as described in claim 1, characterized in that the vaporising device For sequentially connected just flash vaporization slot, first evaporator and whole evaporator, wherein the just flash vaporization slot and the neutralization are dodged Slot connection is steamed, the end evaporator is connect with the high-tower granulation device.

5. a kind of system using chemical industry tail gas production compound fertilizer as claimed in claim 4, characterized in that the end evaporator Waste vapour outlet be connected with the import of vapor seperator, it is described end evaporator taphole and the high-tower granulation device company It connects.

6. a kind of system using chemical industry tail gas production compound fertilizer as claimed in claim 5, characterized in that the evaporation separation The import of device is connected with the outlet of the waste vapour of first evaporator, and the just taphole of evaporator is connected with the import of whole evaporator.

7. a kind of system using chemical industry tail gas production compound fertilizer as described in claim 1, characterized in that the ammonium nitrate solution Preparation unit is connect with washing unit is neutralized；The neutralization washing unit is sequentially connected humidifier and steaming tower, institute It states humidifier import to be connected with the neutralization flash tank gas vent, the neutralization flash tank liquid outlet and vaporising device phase Even, the steaming tower outlet is connected with steam pipe network.

8. a kind of system using chemical industry tail gas production compound fertilizer as described in claim 1, characterized in that the steaming Tower liquid outlet is connect with the neutralization flash tank import, and the steaming tower gas vent is connected with steam pipe network.

9. a kind of method using chemical industry tail gas production compound fertilizer, characterized in that provide system described in claim 1, walk Suddenly are as follows:

1) melamine tail gas enters reactor after passing sequentially through filtering, heat treatment；

2) melamine tail gas that treated generates ammonium nitrate solution with nitric acid pressurization neutralization reaction in the reactor, by generation The molten evaporation and concentration of ammonium nitrate, the neutralized washing of the steam of generation remove；

3) ammonium nitrate solution after being concentrated is prepared into nitro-compound fertilizer using high tower fused melt granulated technique.

10. a kind of method using chemical industry tail gas production compound fertilizer as claimed in claim 9, characterized in that work as melamine It when insufficient, is generated, be the steps include: using liquefied ammonia

1) liquefied ammonia enters reactor after passing sequentially through filtering, heat treatment；

2) neutralization reaction of pressurizeing in the reactor with nitric acid of liquefied ammonia generates ammonium nitrate solution after handling, and the ammonium nitrate of generation is molten It is concentrated by evaporation, the neutralized washing of the steam of generation removes；

3) ammonium nitrate solution after being concentrated is prepared into nitro-compound fertilizer using high tower fused melt granulated technique.