CN207748852U - A kind of system for preparing sulfuric acid and the waste water treatment system being made from it - Google Patents

Abstract

The utility model belongs to technical field of environmental protection in chemical industry, and in particular to a kind of system for preparing sulfuric acid and the waste water treatment system being made from it.System for preparing sulfuric acid provided by the utility model, including heating plant, reforming unit, absorption plant, heating plant include that catalyst layer is arranged at least two-stage heat exchanger, reforming unit inside.Containing SO₂Unstripped gas after heat exchanger stepped heating enter reforming unit, be converted to SO under multistage catalytic oxidant layer catalytic action₃, high conversion rate, it is not necessary that acid-scrubbing cleaning, drying device are arranged before reforming unit, the SO more suitable for moisture content, dust₂Gas expands the scope of application of system for preparing sulfuric acid.The utility model also provides the waste water treatment system for including above system, successively through incinerator, waste-heat recovery device, dust-extraction unit, denitrification apparatus, the processing such as high temperature incineration, waste heat recovery, dedusting, denitration are carried out to acrylic nitrile waste water, retrieval of sulfuric acid is carried out subsequently into system for preparing sulfuric acid, the energy is saved, production cost is reduced.

Description

A kind of system for preparing sulfuric acid and the waste water treatment system being made from it

Technical field

The utility model belongs to technical field of environmental protection in chemical industry, and in particular to a kind of system for preparing sulfuric acid and the waste water being made from it Processing system.

Background technology

Contact process is segmented into three phases：SO is prepared first₂Gas, then under the action of catalyst by SO₂Turn It is melted into SO₃, finally use water or aqueous sulfuric acid to SO₃Absorb and forms sulfuric acid.Wherein, SO₂It is converted to SO₃Technique master To use two kinds of dry and wet：(1) dry process, SO are used₂Double-absorption life is carried out again after first passing through acid-scrubbing cleaning, drying At sulfuric acid, that is, need in SO₂Drying device is added before conversion；(2) wet processing is used, primarily solves the problems, such as it is that guarantee is dense The concentration of sulfuric acid, and control SO in emission₃Content in 18mg/m³Hereinafter, as in existing frequently-used Top's rope technique, Nucleus control device is added before condensation of sulfuric acid device, is burnt using methyl-silicone oil and is generated SiO₂As nucleus and SO₃Enter sulfuric acid together Condenser contributes to condensation of sulfuric acid at drop without forming acid mist.In actual production, SO₂In addition to coming from sulfur burning gas, Huang Iron ore combustion gas, non-ferrous metal metallurgy flue gas can also be transformed by other sulfur-containing compounds, as in acrylonitrile process by sulphur The SO that ammonium aoxidizes₂, sulfur waste acid cleavage generate SO₂, but the SO₂Fluctuation of concentration is larger, especially works as SO₂When concentration is relatively low, It is then difficult to meet the needs that contact method prepares sulfuric acid.Therefore, the equipment of existing contact process method is improved, seeks one Plant the SO of simple in structure and suitable low concentration₂The production equipment of conversion, it has also become the emphasis of relieving haperacidity industry at present.

Acrylonitrile is a kind of important Organic Chemicals, is generally produced using propylene and propane method for ammoxidation.Propylene Nitrile or propane, ammonia and oxygen generate acrylonitrile and by-product by fluidized-bed reactor, enter back into recycling and refining system purifying third Alkene nitrile (USP3936360).There are some unreacted ammonia in admixture of gas after the reaction, to ensure the quality of acrylonitrile, It must be driven off unreacted ammonia.United States Patent (USP) USP3649179 and USP3936360 are removed using sulfuric acid, hydrochloric acid, phosphoric acid or nitric acid Unreacted ammonia.Sulfuric acid is mostly used in China's acrylonitrile industrial production greatly and reacts the method for generation ammonium sulfate with ammonia to remove not instead The ammonium sulfate generated is recycled as chemical fertilizer by the ammonia answered, and mother liquor then enters incinerator and burns.Mother liquor can release when being burned SO₂、NO₂Equal gases, secondary pollution is caused to environment；And contain a large amount of waste heats, direct emission waste of resource in tail gas.Therefore, Develop a set of high efficiency, at low cost processing acrylic nitrile waste water equipment will be of great significance.

Utility model content

Therefore, the technical problem to be solved by the present invention is to overcome acrylic nitrile waste water processing waste water knot in the prior art The problem that structure is complicated, energy consumption is more, and a kind of energy-efficient and simple in structure acrylic nitrile waste water processing system is provided.

For this purpose, the technical solution that the application takes is：

The utility model provides a kind of system for preparing sulfuric acid, including：

Heating plant, including at least two-stage heat exchanger, be provided on every grade of heat exchanger first entrance, first outlet, Second entrance, second outlet；

Reforming unit, be internally provided with the one-to-one catalyst layer of the heat exchanger, offer position on wall surface The conversion entrance of both sides, conversion outlet above and below every grade of catalyst layer；

Absorption plant has and absorbs gas entrance, absorbent entrance and taphole；

Along airflow direction, the conversion entrance phase of the first outlet and catalyst layer described in initial stage of heat exchanger described in most final stage Connection, the first outlet of the heat exchanger in addition to final stage are connected with the first entrance of heat exchanger described in its next stage；Most The conversion outlet of catalyst described in final stage is connected with the absorption gas entrance, and the catalyst layer in addition to most final stage turns Mouth is dissolved with the conversion entrance of catalyst layer described in next stage to be connected.

Optionally, the conversion outlet of the catalyst layer in addition to most final stage enters with the second of the corresponding heat exchanger Mouthful be connected, the second outlet of heat exchanger described in initial stage is connected with the absorption gas entrance, in addition to initial stage described in The conversion entrance of the next stage catalyst layer of the corresponding catalyst layer of second outlet of heat exchanger is connected.

Optionally, the conversion entrance is located at the top of every grade of catalyst layer, and the conversion outlet is located at every grade of institute State the lower section of catalyst layer.

Optionally, further include cooling device, the cooling device includes surge tank and cooler, the entrance of the surge tank It is connected with the taphole, the outlet of the surge tank is connected with the entrance of the cooler；In the cooler Return line is also set up between outlet and the entrance of the surge tank.

Optionally, it is additionally provided with conveying device between the outlet and the entrance of the cooler of the surge tank.

Optionally, the absorption plant is packed tower or plate column；The absorption gas entrance is located at the absorption plant Lower part, the absorbent entrance is located at the top of the absorption plant, and the taphole is located at the bottom of the absorption plant End；The absorption plant top is further opened with waste gas outlet.

The utility model also provides a kind of waste water treatment system including above-mentioned system for preparing sulfuric acid.

Optionally, further include incinerator connected in sequence, waste-heat recovery device, dust-extraction unit, denitrification apparatus；It is described de- The outlet of nitre device is connected with the first entrance of heat exchanger described in initial stage.

Optionally, the incinerator has waterwater entrance, fuel inlet, fuel gas inlet and incineration tail gas is helped to export；Institute Incineration tail gas outlet is stated with the waste-heat recovery device entrance to be connected.

Optionally, the ammonia source inlet being connected with external ammonia source is additionally provided on the denitrification apparatus.

Technical solutions of the utility model have the following advantages that：

1. system for preparing sulfuric acid provided by the utility model, including heating plant, reforming unit and absorption plant.Wherein, it supplies Thermal is internally provided with and the one-to-one catalyst layer of heat exchanger including at least two-stage heat exchanger, reforming unit.

Containing SO₂Unstripped gas after heat exchanger stepped heating, reforming unit is entered by most final heat exchanger, in multistage catalytic It is converted to SO under oxidant layer catalytic action₃, high conversion rate, without before reforming unit be arranged acid-scrubbing cleaning, drying device, be suitable for The more SO of moisture content, dust₂Gas expands the scope of application of system for preparing sulfuric acid, and simple in structure, and operation simplifies, at This reduction.

2. system for preparing sulfuric acid provided by the utility model, the exhanst gas outlet of the catalyst layer in addition to most final stage with it is corresponding The second medium entrance of heat exchanger is connected, and the second medium outlet of initial stage heat exchanger is connected with conversion gas entrance, except most The second medium of heat exchanger except primary exports the smoke inlet phase of the next stage catalyst layer of corresponding catalyst layer Connection.

Containing SO₂Unstripped gas reach SO after multi-stage heat exchanger heats₂→SO₃Conversion temperature, passed through in reforming unit One stage catalyzing oxidant layer catalysis, part SO₂It is converted into SO₃, obtain the higher SO of temperature₂、SO₃Gaseous mixture, then by second medium Entrance enters heat exchanger at the same level, contains SO to entering the low temperature in heat exchanger by first medium entrance₂Unstripped gas heated, so SO afterwards₂、SO₃Gaseous mixture enter back into reforming unit by the further catalyzed conversion of next stage catalyst layer.The Sulphuric acid system of this structure System, makes full use of the higher SO of temperature₂、SO₃Gaseous mixture to containing SO₂Unstripped gas carry out Multi-stage heating, be not necessarily to external heat source, Energy is saved, production cost is reduced；Meanwhile containing SO₂、SO₃Gaseous mixture by multistage catalytic oxidant layer catalyzed conversion, improve SO₂→ SO₃Conversion ratio.

3. system for preparing sulfuric acid provided by the utility model, absorption plant is packed tower or plate column, is absorbent and SO₃ Larger contact area is provided, SO is conducive to₃It is converted into sulfuric acid, the generation of tower top acid mist is reduced, saves in Top's rope technique Combusting silicone oil equipment reduces investment cost and operating cost.

4. system for preparing sulfuric acid provided by the utility model, in absorbent to SO₃During being absorbed, absorption plant Temperature can rise, the cooling device after absorption plant, and the sulfuric acid generated to absorption plant cools down, and is further reduced acid mist Generation, improve SO₃→H₂SO₄Conversion ratio；Meanwhile buffer unit is also set up between absorption plant and cooling device, it is cooling Return line is set between the outlet and buffer unit entrance of device, recycle acid amount is small, reduces equipment size, reduces energy consumption.

5. waste water treatment system provided by the utility model, acrylic nitrile waste water successively through incinerator, waste-heat recovery device, Dust-extraction unit and denitrification apparatus, incinerator carry out high temperature incineration to acrylic nitrile waste water, in acrylic nitrile waste water a large amount of sulphur ammonium with And minimal amount of acrylonitrile, acetonitrile, hydrogen cyanide are converted into SO₂、CO₂、H₂O and NO_xEqual high temperature incineration tail gas, incinerator it After waste-heat recovery device is set, to recycle the heat in high temperature incineration tail gas, save the energy, reduce production cost.

Dust-extraction unit and denitrification apparatus are set gradually after waste-heat recovery device, dust-extraction unit removes low temperature incineration tail gas In dust, catalyst poisoning when avoiding subsequent denitration reaction；Denitrification apparatus selects SCR denitration reactor, and temperature is relatively low, with Follow-up SO₂→SO₃Conversion temperature be closer to, denitration tail gas be not required to excessively heat up or cooling, you can carry out next step SO₂→SO₃The energy is saved in conversion, reduces production cost.

Description of the drawings

In order to make the content of the utility model be more likely to be clearly understood, below according to the specific implementation of the utility model Example and in conjunction with attached drawing, the utility model is described in further detail, wherein：

Fig. 1 is the system for preparing sulfuric acid structural schematic diagram realized described in the utility model embodiment 1；

Fig. 2 is the waste water treatment system structural schematic diagram realized described in the utility model embodiment 1；

Reference numeral is expressed as in figure：

1- heating plants；11- first order heat exchangers；111- first order first entrances；112- first order first outlets；113- First order second entrance；114- first order second outlets；The second level 12- heat exchanger；The second level 121- first entrance；122- second Grade first outlet；The second level 123- second entrance；The second level 124- second outlet；

2- reforming units；21- first order catalyst layers；The 22- first order converts entrance；23- first order conversion outlet；24- Second level catalyst layer；The second level 25- converts entrance；The conversion outlet of the second level 26-；

3- absorption plants；31- absorbs gas entrance；32- absorbent entrances；33- tapholes；34- waste gas outlets；

4- cooling devices；41- surge tanks；42- coolers；421- third entrances；422- thirds export；43- conveying devices；

5- incinerators；51- waterwater entrances；52- fuel inlets；53- helps fuel gas inlet；54- incineration tail gas exports；

6- waste-heat recovery devices；61- high-temperature flue gas entries；62- low-temperature flue gas exports；The 4th entrances of 63-；64- the 4th goes out Mouthful；

7- dust-extraction units；

8- denitrification apparatus；81- ammonia source inlets；

The first pipelines of 901-；The second pipelines of 902-；903- third pipelines；The 4th pipelines of 904-；The 5th pipelines of 905-；906- 6th pipeline；The 7th pipelines of 907-；The 8th pipelines of 908-；The 9th pipelines of 909-；The tenth pipelines of 910-；The 11st pipelines of 911-； The 12nd pipelines of 912-；The 13rd pipelines of 913-；The 14th pipelines of 914-；The 15th pipelines of 915-；The 16th pipelines of 916-； The 17th pipelines of 917-；The 18th pipelines of 918-；The 19th pipelines of 919-；The 20th pipelines of 920-；The 21st pipelines of 921-.

Specific implementation mode

The technical solution of the utility model is clearly and completely described below in conjunction with attached drawing, it is clear that described Embodiment is the utility model a part of the embodiment, instead of all the embodiments.Based on the embodiments of the present invention, originally The every other embodiment that field those of ordinary skill is obtained without making creative work, belongs to this practicality Novel protected range.As long as in addition, technical characteristic involved in the utility model different embodiments disclosed below Not constituting a conflict with each other can be combined with each other.

Embodiment 1

The present embodiment provides a kind of system for preparing sulfuric acid, as shown in Figure 1, including：Heating plant 1, absorbs dress at reforming unit 2 Set 3, cooling device 4.

Wherein, heating plant 1 includes at least two-stage heat exchanger, and first entrance, first are provided on every grade of heat exchanger Outlet, second entrance, second outlet.

In the present embodiment, along airflow direction, heating plant 1 is two-stage heat exchanger：First order heat exchanger 11 and the second level are changed Hot device 12.First order first entrance 111, first order first outlet 112, the first order second is provided on first order heat exchanger 11 to enter Mouth 113 and first order second outlet 114；Second level first entrance 121 is provided on second level heat exchanger 12, the second level first goes out Mouth 122, second level second entrance 123 and second level second outlet 124.First order first outlet 112 by the first pipeline 901 with Second level first entrance 121 is connected.

Dividing wall type heat exchanger may be selected in first order heat exchanger 11 and second level heat exchanger 12, such as jacketed type exchanger, board-like Heat exchanger or shell-and-tube heat exchanger.

In the present embodiment, first order heat exchanger 11 and second level heat exchanger 12 are shell-and-tube heat exchanger.

As shown in Figure 1, reforming unit 2 be internally provided with the one-to-one catalyst layer of heat exchanger, open up on wall surface Have positioned at the conversion entrance of both sides, the conversion outlet up and down of every grade of catalyst layer.

In the present embodiment, reforming unit 2 is vertical reaction tower, and a partition board is arranged in reaction tower, reaction tower inner cavity is divided into Mutual disconnected two inner cavities up and down.First order catalyst layer 21, corresponding side wall are provided with along airflow direction, upper lumen On offer first order conversion entrance 22 above first order catalyst layer 21, positioned at the lower section of first order catalyst layer 21 First order conversion outlet 23；It is provided with second level catalyst layer 24 in lower lumen, is offered positioned at second on corresponding side wall The second level conversion entrance 25 of 24 top of grade catalyst layer converts outlet positioned at the second level of 24 lower section of second level catalyst layer 26.Second level first outlet 122 converts entrance 22 with the first order by the second pipeline 902 and is connected, first order conversion outlet 23 It is connected with second level second entrance 123 by third pipeline 903, second level second outlet 124 passes through the 4th pipeline 904 and Two level conversion entrance 25 is connected, and second level conversion outlet 26 is connected by the 5th pipeline 905 with first order second entrance 113 It connects.

As shown in Figure 1, absorption plant 3 is vertical absorption tower, it is provided in bottom sidewall and absorbs gas entrance 31, upper side Absorbent entrance 32 is provided on wall；The bottom end of reforming unit 3 is provided with taphole 33, and top is provided with waste gas outlet 34. It absorbs gas entrance 31 by the 6th pipeline 906 to be connected with first order second outlet 114, the 7th is connected on absorbent entrance 32 Pipeline 907 is connected with the 8th pipeline 908 on waste gas outlet 34.Packed absorber, turbulent contact absorber, plate may be selected in absorption plant 3 Formula absorption tower, wherein filler is the anticorrosion materials such as ceramic packing, polytetrafluoroethylene (PTFE) valve stem packing in packed absorber.

In the present embodiment, absorption plant 3 is packed absorber, and selected filler is ceramic packing.

As shown in Figure 1, cooling device 4 includes surge tank 41 and cooler 42.The entrance of surge tank 41 passes through the 9th pipeline 909 are connected with taphole 33, and the outlet of surge tank 41 is connected by the tenth pipeline 910 with the entrance of cooler 42, cold But it is connected with the 11st pipeline 911 in the outlet of device 42.Third entrance 421 and third outlet 422 are set on cooler 42.It is cooling Dividing wall type heat exchanger may be selected in device 42, such as jacketed type exchanger, plate heat exchanger, shell-and-tube heat exchanger.In going out for cooler 42 The 12nd pipeline 912 is additionally provided between mouth and the entrance of surge tank 41, the 12nd pipeline 912 and the tenth pipeline 910 composition are closed Circuit is closed, and setting conveying fills 43 on the tenth pipeline 910, is carried out for the liquid in surge tank 41 to be delivered to cooler 42 Cooling down.Centrifugal pump, reciprocating pump may be selected in conveying device 43.

In the present embodiment, cooler 42 is shell-and-tube heat exchanger, and conveying device 43 is centrifugal pump.

The operation principle of this structure system for preparing sulfuric acid is：A upper process contains SO₂Unstripped gas by first order first entrance 111 Into first order heat exchanger 11, enter in second level heat exchanger 12 after the heating of first order heat exchanger 11, then by the first pipeline 901 It is heated again, at this point, containing SO₂Unstripped gas reach SO₂→SO₃Conversion temperature, then through the second pipeline 902 enter turn 2 upper lumen, under 21 catalytic action of first order catalyst layer, the part SO in unstripped gas are set in makeup₂It is converted into SO₃, obtain Conversion gas for the first time, it is SO to convert gas for the first time₂、SO₃Mixture.Since the reaction is exothermic reaction, gas is converted for the first time Temperature is higher, enters in second level heat exchanger 12, with second level heat exchanger 12 through third pipeline 903 and contains SO₂Unstripped gas hair Raw second level heat exchange reduces and converts gas own temperature for the first time to SO₂→SO₃Conversion temperature, in favor of converting gas for the first time Catalyzed conversion again, while improving the temperature of the unstripped gas in second level heat exchanger 12.For the first time after the cooling of conversion gas, by the 4th Pipeline 904 enters the lower lumen of reforming unit 2, in the second level under the action of catalyst layer 24, carries out secondary catalysis and turns Change so that remaining SO in conversion gas for the first time₂It is completely converted into SO₃, obtain higher second of conversion gas of temperature.Second It converts gas and enters first order heat exchanger 11 by the 5th pipeline 905, contain SO in first order heat exchanger 11₂Unstripped gas occur First order heat exchange, to improve the temperature of the unstripped gas in first order heat exchanger 11.Due to SO₂→SO₃Reaction is that reversible heat release is anti- It answers, conventional primary conversion is difficult to take higher conversion ratio to, and the present embodiment is to containing SO₂Unstripped gas carry out two-stage catalysis turn Change, improves conversion ratio.What is more important, the first time conversion temperature degree flowed out from reforming unit 2 is higher, is unfavorable for SO₂ →SO₃Forward reaction, then next stage catalyzed conversion could be entered by needing to drop it, and the utility model is using conversion gas to raw material Gas is heated, and to improve the temperature of unstripped gas, unstripped gas is made to reach SO₂→SO₃Conversion temperature, while reducing conversion gas Temperature is conducive to the catalyzed conversion again for converting gas.First order heat exchanger 11 and second level heat exchanger 24 are correspondingly arranged, second Grade heat exchanger 12 is correspondingly arranged with first order heat exchanger 21, and the higher conversion gas of temperature is made full use of to carry out multistage add to unstripped gas Heat is not necessarily to external heat source and low-temperature receiver, saves energy, reduces production cost.Moreover, system provided by the utility model is not necessarily to turning Setting acid-scrubbing cleaning, drying device before makeup sets 2, are suitable for the more SO of moisture content, dust₂Gas expands Sulphuric acid system The scope of application of system, it is simple in structure, it is easily operated.

Second of conversion gas is SO₃Gas is entered by the 6th pipeline 906 after the cooling of first order heat exchanger 11 and absorbs dress 3 are set, absorption plant 3 is ceramic packing tower, SO₃Rise from bottom to top along packing layer, meanwhile, it is passed through 30 DEG C by the 7th pipeline 907 Sulfuric acid weak solution as absorbent from top to bottom along filler laminar flow, SO₃It is absorbed to form sulfuric acid concentrated solution by sulfuric acid weak solution, And it is discharged by taphole 33.Wherein, sulfuric acid weak solution and SO₃Molar ratio be 2: 5~2: 1.

In the present embodiment, sulfuric acid weak solution and SO₃Molar ratio be 2: 3.

Packing layer in absorption plant 3 is sulfuric acid weak solution and SO₃Larger contact area is provided, SO is conducive to₃It is converted into Sulfuric acid.Although SO₃Cool down through first order heat exchanger 11, but temperature is still higher (280 DEG C of ＞), and SO₃It can also be put when absorbing Go out a large amount of heat, generate a large amount of acid mists, etching apparatus, absorbent may be selected de- desalted water or inorganic acid less than 40 DEG C, have Conducive to the generation of acid mist is reduced, the combusting silicone oil equipment in Top's rope technique is saved, reduces investment cost and operating cost；Together When, waste gas outlet 34 is set on 3 top of absorption plant, a small amount of acid mist is discharged, maintains the stable gas pressure in absorption plant 3.

The sulfuric acid concentrated solution temperature of generation is higher, enters surge tank 41 through the 9th pipeline 909, under the effect of conveying device 43 It is delivered to cooler 42, heat exchange is carried out with the cooling water for being passed through cooler 42 by third entrance 421, to reduce sulfuric acid concentrated solution Temperature.Sulfuric acid concentrated solution is produced through 42 rear portion of cooler, and another part is back to surge tank by the 12nd pipeline 912 41, reduce the temperature of sulfuric acid solution in surge tank 41.According to actual needs, the ratio of extraction and the reflux of sulfuric acid is controlled.This reality It applies example and cooling device 4 is set after absorption plant 3, the sulfuric acid concentrated solution generated to absorption plant 3 cools down, and further subtracts The generation of few acid mist, improves SO₃→H₂SO₄Conversion ratio；Meanwhile cooling device 4 is closing of constituting of surge tank 41 and cooler 42 Circuit is closed, realizes the multiple circulation temperature lowering to sulfuric acid concentrated solution, and recycle acid amount is small, equipment size is small, at low cost.

Embodiment 2

The present embodiment provides a kind of waste water treatment systems, as shown in Fig. 2, including：Incinerator 5, waste-heat recovery device 6, The system for preparing sulfuric acid that dust-extraction unit 7, denitrification apparatus 8 and embodiment 1 provide.

As shown in Fig. 2, being provided with waterwater entrance 51, fuel inlet 52 on incinerator 5, helping fuel gas inlet 53 and burning tail Gas outlet 54.Wherein, it is connected with the 13rd pipeline 913 on waterwater entrance 51, the 14th pipeline is connected on fuel inlet 52 914, it helps on fuel gas inlet 53 and is connected with the 15th pipeline 915.

As shown in Fig. 2, being provided with high-temperature flue gas entry 61 on waste-heat recovery device 6, low-temperature flue gas exports the 62, the 4th entrance 63, the 4th outlet 64.Wherein, high-temperature flue gas entry 61 is connected by the 16th pipeline 916 with incineration tail gas outlet 54；4th Entrance 63 is connected with the 17th pipeline 917, for being passed through cold medium into waste-heat recovery device 6, by cooling high-temperature fume；4th Outlet 64 is connected with the 18th pipeline 918, and the heat absorbed in waste-heat recovery device 6 is discharged, with using it for anything else.Waste heat recovery Waste heat boiler or the heat exchanger of other forms can be selected in device 6.In the present embodiment, waste heat boiler is selected.

As shown in Fig. 2, dust-extraction unit 7 is used to remove the dust in waste-heat recovery device 6 in low-temperature flue gas.Dust-extraction unit 7 Entrance be connected by the 19th pipeline 919 and low-temperature flue gas outlet 62.

As shown in Fig. 2, the NO in the incineration tail gas that denitrification apparatus 8 is used to generate incinerator 5_xIt is converted into N₂.Denitration fills It sets 8 entrance by the 20th pipeline 920 to be connected with the outlet of dust-extraction unit 7, the outlet of denitrification apparatus 8 passes through the 21st Pipeline 921 is connected with the first order first entrance 111 for the system for preparing sulfuric acid that embodiment 1 provides.Ammonia source is set on denitrification apparatus 8 Entrance 81, for providing ammonia source to denitrification apparatus 8.

The operation principle of above-mentioned acrylic nitrile waste water processing system is：By the waste water containing sulphur ammonium through the 13rd pipeline 913 into Enter incinerator 5, with the fuel being passed through by the 14th pipeline 914, the combustion-supporting gas being passed through by the 15th pipeline 915 in incinerator It is mixed in 5, at 1100~1200 DEG C, the residence time is 0.2~1.0S, converts sulphur ammonium contained in waste water to for temperature control SO₂Equal gaseous mixtures.Since the waste water containing sulphur ammonium is the sulphur ammonium waste liquid or four-effect evaporation residual night that acrylonitrile preparation process generates In one kind, also contain a small amount of acrylonitrile, acetonitrile, hydrogen cyanide etc., wherein the mass fraction of sulphur ammonium is 3~30%, SO₂It is mixed It closes in gas and also contains NO_x、CO、CO₂And H₂O etc..

In the present embodiment, the incineration temperature of incinerator 5 is 1150 DEG C, residence time 0.5S, and the combustion-supporting gas being passed through is Contain CO₂、CO、NO_xAir.

Since the temperature of high temperature incineration tail gas is up to 1000 DEG C, to recycle its waste heat, by the high temperature incineration tail gas through the tenth Six pipelines 916 be passed through waste-heat recovery device 6 carry out waste heat recovery, control waste-heat recovery device 6 in absolute pressure be 105~ 110kPa.Cooling water is passed through into the 17th pipeline 917, cooling water exchanges heat in waste-heat recovery device 6 with high temperature incineration tail gas Become saturated vapor afterwards, be discharged by the 18th pipeline 918, used as other process, improves waste heat utilization.Through waste heat recovery The low temperature incineration tail gas dustiness of 6 gained of device is higher, then is passed through 7 dedusting of dust-extraction unit by the 19th pipeline 919 and is purified Incineration tail gas, denitrification apparatus 8 is then passed through by the 20th pipeline 920.From ammonia source inlet 81 ammonia is passed through into denitrification apparatus 8 Source, such as ammonia, ammonium hydroxide, and containing NO_xPurification incineration tail gas occur SCR reaction, reaction temperature be 200~400 DEG C, by NO_x's It is converted to N₂And H₂O.Denitration tail gas enters the system for preparing sulfuric acid of subsequent processing, carries out SO₂Conversion absorbs, and equipment and process are same Described in embodiment 1.

In the present embodiment, ammonia source is ammonium hydroxide, and denitration reaction temperature is 350 DEG C.

Embodiment 3

The present embodiment provides a kind of system for preparing sulfuric acid, compared with the system for preparing sulfuric acid that embodiment 1 provides, difference lies in： The top that gas entrance 31 is located at absorption plant 3 is absorbed, absorbent entrance 32 is located at the top of absorption plant 3, and the two is from upper And lower movement, it can also realize SO₃Absorption；

As deformation, absorption plant 3 selects tubulent contact tower, built-in a certain number of lightweight bead fillers to utilize the rapids of bead Dynamic rotation, improves absorption efficiency.

Embodiment 4

The present embodiment provides a kind of system for preparing sulfuric acid, compared with the system for preparing sulfuric acid that embodiment 1 or embodiment 3 provide, Difference lies in：Return line and conveying device 43 are not provided between the outlet of cooler 42 and the entrance of surge tank 41, but Cooler 42 is arranged in the lower section of surge tank 41, using directly producing sulfuric acid concentrated solution under gravity.

Embodiment 5

The present embodiment provides a kind of system for preparing sulfuric acid, with embodiment 1, the system for preparing sulfuric acid of any offer of embodiment 3 or 4 It compares, difference lies in：It is not provided with cooling device 4, but sulfuric acid concentrated solution prepared by absorption plant 3 carries out natural cooling, together The acid mist that Shi Liyong decompressors generate absorption plant 3 is discharged, and reduces the corrosion of absorption plant 3.

Embodiment 6

The present embodiment provides a kind of system for preparing sulfuric acid, with embodiment 1, the system for preparing sulfuric acid of any offers of embodiment 3-5 It compares, difference lies in：Conversion entrance is located at the lower section of every grade of catalyst layer, and conversion outlet is located at the top of every grade of catalyst layer, Also the effect of above-mentioned catalyzed conversion can be realized.

Embodiment 7

The present embodiment provides a kind of system for preparing sulfuric acid, with embodiment 1, the system for preparing sulfuric acid of any offers of embodiment 3-6 It compares, difference lies in：Using external heat source to containing SO₂Unstripped gas heated, be allowed to be warming up to SO₂→SO₃Conversion temperature Degree；Every grade of conversion gas is cooled down using additional low-temperature receiver, is allowed to be cooled to SO₂→SO₃Conversion temperature, can also realize this reality With novel effect.

Embodiment 8

The present embodiment provides a kind of system for preparing sulfuric acid, with embodiment 1, the system for preparing sulfuric acid of any offers of embodiment 3-7 It compares, difference lies in：The setting series of heat exchanger is three-level, level Four, Pyatyi etc., accordingly, reforming unit in heating plant 1 The setting series of catalyst layer is three-level, level Four or Pyatyi etc. in 2, using the conversion gas of certain catalyst layer to corresponding heat exchange Unstripped gas in device is heated.

Embodiment 8

The present embodiment provides a kind of waste water treatment systems, and compared with the waste water treatment system that embodiment 8 provides, difference exists In：Along incineration tail gas flow direction, dust-extraction unit 7, waste-heat recovery device 6 and denitrification apparatus 8 or other companies are set gradually Mode is connect, as long as the waste heat in incineration tail gas can be recycled, and contained dust, NO can be removed_x.

Obviously, the above embodiments are merely examples for clarifying the description, and does not limit the embodiments.It is right For those of ordinary skill in the art, can also make on the basis of the above description it is other it is various forms of variation or It changes.There is no necessity and possibility to exhaust all the enbodiments.And it is extended from this it is obvious variation or Among the protection domain that variation is created still in the utility model.

Claims (10)

1. a kind of system for preparing sulfuric acid, which is characterized in that including：

Heating plant (1), including at least two-stage heat exchanger are provided with first entrance, first outlet, on every grade of heat exchanger Two entrances, second outlet；

Reforming unit (2), be internally provided with the one-to-one catalyst layer of the heat exchanger, offer on wall surface and be located at The conversion entrance of both sides, the conversion outlet up and down of every grade of catalyst layer；

Absorption plant (3) has and absorbs gas entrance (31), absorbent entrance (32) and taphole (33)；

Along airflow direction, the first outlet of heat exchanger described in most final stage is connected with the conversion entrance of catalyst layer described in initial stage It connects, the first outlet of the heat exchanger in addition to final stage is connected with the first entrance of heat exchanger described in its next stage；Most end The conversion outlet of the grade catalyst is connected with the absorption gas entrance (31), the catalyst layer in addition to most final stage Conversion outlet is connected with the conversion entrance of catalyst layer described in next stage.

2. system for preparing sulfuric acid according to claim 1, which is characterized in that turn of the catalyst layer in addition to most final stage It dissolves mouth with the second entrance of the corresponding heat exchanger to be connected, the second outlet of heat exchanger described in initial stage and the absorption Gas entrance (31) is connected, under the corresponding catalyst layer of the second outlet of the heat exchanger in addition to initial stage The conversion entrance of one stage catalyzing oxidant layer is connected.

3. system for preparing sulfuric acid according to claim 1 or 2, which is characterized in that the conversion entrance be located at every grade described in urge The top of agent layer, the conversion outlet is positioned at the lower section of every grade of catalyst layer.

4. system for preparing sulfuric acid according to claim 1 or 2, which is characterized in that further include cooling device (4), the cooling Device (4) includes surge tank (41) and cooler (42), and the entrance of the surge tank (41) is connected with the taphole (33) It connects, the outlet of the surge tank (41) is connected with the entrance of the cooler (42).

5. system for preparing sulfuric acid according to claim 4, which is characterized in that delay with described in the outlet of the cooler (42) It rushes between the entrance of tank (41) and is provided with return line, and entering in the outlet of the surge tank (41) and the cooler (42) It is provided with conveying device (43) between mouthful.

6. system for preparing sulfuric acid according to claim 1 or 2, which is characterized in that the absorption plant (3) be packed tower or Plate column；The lower part for absorbing gas entrance (31) and being located at the absorption plant (3), the absorbent entrance (32) is located at described The top of absorption plant (3), the taphole (33) are located at the bottom end of the absorption plant (3)；Absorption plant (3) top End is further opened with waste gas outlet (34).

7. a kind of waste water treatment system including any system for preparing sulfuric acid of claim 1-6.

8. waste water treatment system according to claim 7, which is characterized in that

Further include incinerator connected in sequence (5), waste-heat recovery device (6), dust-extraction unit (7), denitrification apparatus (8)；It is described The outlet of denitrification apparatus (8) is connected with the first entrance of heat exchanger described in initial stage.

9. waste water treatment system according to claim 8, which is characterized in that the incinerator (5) has waterwater entrance (51), fuel inlet (52), help fuel gas inlet (53) and incineration tail gas to export (54)；Incineration tail gas outlet (54) with it is described Waste-heat recovery device (6) entrance is connected.

10. waste water treatment system according to claim 8 or claim 9, it is additionally provided with and external ammonia source on the denitrification apparatus (8) The ammonia source inlet (81) being connected.