CN105217585B - Double pressurized method nitric acid production plant - Google Patents
Double pressurized method nitric acid production plant Download PDFInfo
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- CN105217585B CN105217585B CN201410244264.1A CN201410244264A CN105217585B CN 105217585 B CN105217585 B CN 105217585B CN 201410244264 A CN201410244264 A CN 201410244264A CN 105217585 B CN105217585 B CN 105217585B
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Abstract
The invention provides a kind of double pressurized method nitric acid production plant, including ammonia feeding material component, air feeding material component, ammonia sky blender and Reconstruction of End Gas Separator；Wherein, ammonia feeding material component includes the ammonia evaporator, ammonia superheater, the ammonia filter that are sequentially connected by ammonia conveyance conduit, the output end of ammonia filter is connected by ammonia conveyance conduit with the ammonia entrance of ammonia sky blender, and ammonia control valve and ammonia emptying valve are disposed with along ammonia conveying direction on the ammonia conveyance conduit between ammonia superheater and ammonia filter；Air feeding material component includes air compressor machine, airflow pipe；Gas discharge outlet of the double pressurized method nitric acid production plant also including one end and Reconstruction of End Gas Separator is connected, the gas pipeline that the other end is connected on the ammonia conveyance conduit between ammonia control valve and ammonia superheater.Using device of the invention, tail gas tieback to ammonia conveyance conduit is carried out into the empty ratio experiment of ammonia instead of ammonia before nitric acid production, greatly reducing the ammonia cost in debugging stage.
Description
Technical Field
The invention belongs to the technical field of nitric acid production, and particularly relates to a nitric acid production device adopting a double-pressurization method.
Background
The most common method in the prior industrial dilute nitric acid production method is to adopt a double-pressurization method, firstly, two raw material gases, namely 0.45MPa air and 0.52MPa ammonia gas are subjected to primary pressurization oxidation under a platinum mesh catalyst according to a certain proportion to generate NOx, then the NOx and secondary air are pressurized to 1.1MPa through a nitrogen oxide compressor again, and then the NOx and the secondary air are absorbed in an absorption tower to generate dilute nitric acid.
The most important thing in the whole production process is the control of the mixing ratio of the raw material gas air and the ammonia gas, because the ammonia gas is a dangerous substance B, the ignition temperature is 651 ℃, the explosion limit is 15.5-27.0% volume fraction, and once the ammonia gas concentration in the ammonia-air mixing gas chamber is in the range, the explosion risk exists. Therefore, the ratio of the two raw material gases to be delivered needs to be strictly controlled, and the ammonia air ratio is generally controlled to be about 9.6% in domestic production, and about 9% in Japan. Wherein the control of the ammonia-air ratio is carried out in the production by using the device shown in figure 1, and figure 1 is a schematic diagram of the existing nitric acid production device by a double-pressurization method; raw material liquid ammonia is evaporated through an ammonia evaporator A and an ammonia evaporator B, the gas ammonia enters an ammonia superheater for heating again, and then is filtered and purified, enters an ammonia-air mixer together with air compressed by an air compressor to be mixed in a certain proportion, and then is oxidized.
Before production, operators adjust the flow rates of the ammonia gas and the air through an ammonia flow meter, an air flow meter and a central control ammonia air ratio display, and in order to make the ratio accurate, the operators test several ratios of 7%, 8%, 9% and 9.5%, and each value is operated for 4 times until the ammonia air ratio reaching the process requirement is stable. When each operation is carried out, the ammonia gas in the pipeline after the previous operation is finished must be emptied to ensure the accuracy of the next operation, so that the process is repeated to cause a large amount of waste of the raw material ammonia, and the ammonia gas discharged by a direct test causes bad smell and environmental pollution.
Disclosure of Invention
The embodiment of the invention aims to overcome the defects in the prior art and provide the double-pressurization method nitric acid production device for returning tail gas to the ammonia conveying pipeline to replace ammonia gas for performing the ammonia-to-air ratio test.
In order to achieve the above purpose, the technical solution of the embodiment of the present invention is as follows:
a nitric acid production device adopting a double-pressurization method comprises an ammonia gas feeding assembly, an air feeding assembly, an ammonia-air mixer and a tail gas separator with a gas outlet; wherein,
the ammonia gas feeding assembly comprises an ammonia superheater, an ammonia filter and an ammonia conveying pipeline connecting the ammonia superheater and the ammonia filter; heating ammonia gas by an ammonia superheater, conveying the heated ammonia gas to an ammonia filter by an ammonia conveying pipeline, filtering, and outputting the filtered ammonia gas to an ammonia air mixer by the ammonia filter; an ammonia regulating valve and an ammonia emptying valve are sequentially arranged on the ammonia conveying pipeline along the ammonia conveying direction;
the air feeding assembly comprises an air compressor and an air conveying pipeline which is connected with the output end of the air compressor and the air input interface of the ammonia-air mixer;
the double-pressurization method nitric acid production device further comprises a gas transmission pipeline, wherein one end of the gas transmission pipeline is connected with a gas outlet of the tail gas separator, and the other end of the gas transmission pipeline is connected to an ammonia transmission pipeline between the ammonia regulating valve and the ammonia superheater.
In the ammonia-air ratio adjusting process before nitric acid production, the nitric acid production device adopting the double-pressurization method directly discharges tail gas to the front of an ammonia adjusting valve of an ammonia conveying pipeline, so that the tail gas is used for replacing ammonia to adjust the flow in an ammonia-air ratio adjusting test in the previous stage, and the cost of ammonia in the debugging stage is greatly reduced. In addition, only the air compressor is started to carry out the ammonia-air ratio regulation test in the debugging process, so that the environmental pollution caused by the emission of ammonia gas is reduced. In the test process, the air compressed and conveyed by the air compressor is not subjected to reaction and absorption, and is completely discharged from the tail gas separator in the sealed production device, so that the air tightness in the device can be detected according to the power of the air compressor and the indicating values of various flow meters.
Drawings
The invention will be further described with reference to the accompanying drawings and examples, in which:
FIG. 1 is a schematic diagram of a conventional apparatus for producing nitric acid by a double pressurization method;
FIG. 2 is a schematic diagram of a nitric acid production apparatus by a double pressurization method according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The embodiment of the invention provides a nitric acid production device by a double-pressurization method and a control method, and referring to fig. 2, fig. 2 is a schematic diagram of the nitric acid production device by the double-pressurization method in the embodiment of the invention, and the nitric acid production device comprises an ammonia gas feeding component 10, an air feeding component 20, an ammonia-air mixer 30 and a tail gas separator 40. The ammonia-air mixer 30 has an ammonia gas input port and an air input port. The tail gas separator 40 has a gas discharge port 41 for discharging the separated gas.
The ammonia gas feeding assembly 10 comprises an ammonia evaporator 11, an ammonia superheater 12 and an ammonia filter 13 which are sequentially communicated through an ammonia conveying pipeline 14; the input end of the ammonia evaporator 11 is used for receiving raw material liquid ammonia added in production, and the output end is connected with the input end of the ammonia superheater 12; the output end of the ammonia superheater 12 is connected to a gas ammonia input interface of the ammonia-air mixer 30 through an ammonia filter 13 by an ammonia conveying pipeline 14. The liquid ammonia raw material is evaporated into gaseous ammonia in an ammonia evaporator 11, then the gaseous ammonia is heated by an ammonia superheater 12 and then is sent to an ammonia filter 13 for filtering, and finally the gaseous ammonia is sent to an ammonia input interface of an ammonia-air mixer 30 from the ammonia filter 13 and is mixed with air in the ammonia-air mixer 30. The output end of the ammonia superheater 12 is connected with the input end of the ammonia filter 13 through an ammonia conveying pipeline 14. In order to realize the preparation of the ammonia air ratio, an ammonia gas regulating valve 141 near one end of the ammonia superheater 12 and an ammonia gas emptying valve 142 near one end of the ammonia gas filter 13 are sequentially arranged in the ammonia conveying pipeline 14 along the ammonia conveying direction, so that the flow of the ammonia gas is regulated. An ammonia pressure gauge 143, an ammonia flow meter 144 and an ammonia thermometer 145 are further arranged on the ammonia conveying pipeline 14 between the ammonia gas regulating valve 141 and the ammonia gas emptying valve 142, and specifically, the ammonia pressure gauge 143, the ammonia flow meter 144 and the ammonia thermometer 145 are sequentially arranged from the ammonia gas regulating valve 141 to the ammonia gas emptying valve 142 in the installation sequence of the ammonia pressure gauge 143, the ammonia thermometer 145 and the ammonia flowmeter 144; when the flow of the ammonia gas delivered in the ammonia delivery pipe 14 is regulated by the ammonia gas regulating valve 141, the flow can be checked and verified according to the readings of the ammonia pressure gauge 142 and the ammonia flow meter 143.
The air feeding assembly 20 comprises an air compressor 21 and an air conveying pipeline 22 connected with the output end of the air compressor 21 and the air input end of the ammonia-air mixer 30; the air delivery pipe 22 is provided with an air emptying valve 221, and the air delivery pipe 22 is further provided with an air pressure gauge 222, an air thermometer 223 and an air flow meter 224 which are positioned between the air emptying valve 221 and the ammonia-air mixer 30. Because the power of the air compressor 21 is rated, the air output from the air compressor 21 can be conditioned by the air vent valve 221, and the air gauge 222 and the air flow meter 224 can monitor the air during the conditioning process.
The nitric acid production device adopting the double pressurization method further comprises a gas transmission pipeline 42, wherein one end of the gas transmission pipeline 42 is connected with a gas outlet 41 of the tail gas separator 40 and used for receiving tail gas discharged by the tail gas separator 40; the other end of the gas transmission pipeline 42 is connected to a section of the ammonia transmission pipeline 14 between the ammonia regulating valve 141 and the ammonia superheater 12, and the tail gas is recycled to be used as ammonia gas for an ammonia-to-air ratio test.
In the implementation, the gas transmission pipeline 42 is provided with a stop valve 421 for controlling the on-off of the gas transmission pipeline 42. When the ammonia air ratio test is carried out, the stop valve 421 is opened, and the tail gas is discharged at other times, so that the switching is simple.
In use, a three-way joint (not shown in the figure) can be arranged on the gas outlet 41 of the tail gas separator 40, a first sub-interface of the three-way joint is connected with the gas outlet 41 of the tail gas separator 40, a second sub-interface is used for connecting the gas transmission pipeline 42, and a third sub-interface is used for exhausting tail gas, and the tail gas can be connected back or exhausted by switching the on and off of the second sub-interface and the third sub-interface, so that the operation is simple.
In the production, depending on the amounts of raw gases and off gases of the off gases, in the case of the use according to the invention of the gas line 42, it is preferable to use a DN200 line, the nominal diameter of which is 200mm being the most suitable for the off gas emissions in the production of nitric acid.
Or the three-way joint is replaced by a three-way valve with one inlet and two outlets, the inlet of the three-way valve is connected with the gas outlet 41 of the tail gas separator 40, the first outlet of the three-way valve is connected to the part between the ammonia gas regulating valve 141 and the ammonia superheater 12 on the ammonia conveying pipeline 14 through a gas conveying pipeline 42, and the second outlet is used for tail gas removal. Then in use the three-way valve may itself be on-off regulated so that components such as stop valve 421 may be eliminated from gas line 42.
In addition, the raw material ammonia gas is completely separated in the ammonia-to-air ratio test process conveniently, and the connection with the ammonia conveying pipeline and the switching between the ammonia-to-air ratio test and the production are facilitated when the gas conveying pipeline 42 is connected back to the ammonia conveying pipeline 14; therefore, a flange 121 is arranged at the joint of the output end of the ammonia superheater 12 and the ammonia conveying pipeline 14, firstly, the connection and the assembly of the output end interface of the ammonia superheater 12 and the ammonia conveying pipeline 14 are facilitated, secondly, a flange blind plate can be added on the flange 121 during the ammonia space ratio test, then, the connection of the ammonia superheater 12 and the ammonia conveying pipeline 14 can be directly blocked through the blind plate, so that the interference of residual ammonia gas in the ammonia superheater 12 and the like can be completely avoided during the ammonia space ratio test, and the test is more accurate.
Then, in the ammonia air ratio adjusting process before the nitric acid production, the nitric acid production apparatus adopting the double-pressurization method of the present invention may adopt the gas discharged from the tail gas separator 40 to replace ammonia gas to perform an ammonia air ratio test, and specifically, the following steps may be referred to:
s1, starting the air compressor 21; wherein the air compressor 21 can adopt the type commonly used for producing nitric acid by the existing double-pressurization method, the rotating speed of the air compressor reaches more than 95 percent when the nitric acid is normally produced, the load of a steam turbine is 70 percent, the outlet pressure is 0.27MPa, and the temperature is 206 ℃; the test was also conducted in accordance with the state at the time of production.
S2, check the reading of the air flow meter 224, and open the air release valve 221 by about 20%.
S3, slowly opening the stop valve 421 on the gas transmission pipeline 42 when the air flow meter 224 is stable, and then transmitting the tail gas of the tail gas separator 42 to the ammonia transmission pipeline 14. Of course, according to the above process, in the whole nitric acid production apparatus, since only the air compressor 21 is turned on for air transportation, the tail gas transported into the ammonia transportation pipeline 14 through the gas transportation pipeline 42 is air that is not subjected to the ammoniation and absorption reactions.
S4, checking the indication number of the ammonia pressure gauge 143 on the ammonia conveying pipeline 14 until the indication number of the ammonia pressure gauge 143 is the same as the preset value of the test and tends to be stable, and then opening the ammonia emptying valve 142 by 20 percent. The predetermined value of the ammonia pressure gauge 143 was 0.52MPa in terms of the ammonia air ratio and the flow rate of ammonia gas at the time of production.
And S5, adjusting the ammonia gas adjusting valve 141 according to the ratio of the ammonia-to-air ratio required until the ammonia flow meter 144 and the display numerical value of the central control ammonia-to-air ratio are equal to the set value in the test and tend to be stable.
S6, repeating the operations of steps S1-S5 according to the test values of the ammonia air ratio of 7%, 8%, 9% and 9.5% until all the states of the instruments and the valves accord with the states required in production, finally closing the stop valve 421 and stopping the operation of the device.
In the ammonia-air ratio adjusting process before the production of nitric acid, the gas discharged by the tail gas separator 40 is returned to the front end of the ammonia adjusting valve 141 of the ammonia conveying pipeline 14 by adopting the nitric acid production device adopting the double-pressurization method, so that the flow is adjusted by replacing ammonia in an ammonia-air ratio adjusting test before the production, and the cost of ammonia in the debugging stage is greatly reduced. According to the calculation of benefits in the existing ammonia-air ratio regulation, the unit price of a liquid ammonia raw material is 2600 yuan/ton; the ammonia consumption of each ammonia-air ratio test is 6 tons/time; the number of operators is 4; the operation times are 4 times; the total waste of raw material ammonia is 2600 yuan/ton × 6 ton/times × 4 persons × 4 times 249600 yuan.
In addition, only the air compressor 21 is started for simulation in the debugging process, so that air is discharged in the test process, and the environmental pollution caused by the emission of ammonia gas is reduced. In the simulation process, the air compressed and conveyed by the air compressor 21 is not subjected to reaction and absorption and is completely discharged from the tail gas separator 40 in the sealed production device, the process flow can be opened, an air medium is adopted for carrying out a pre-production test before production, and then whether the air tightness in the device is good or not can be judged according to the power of the air compressor 21 and the indicating values of the flow meters in the test process.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (8)
1. A nitric acid production device adopting a double-pressurization method comprises an ammonia gas feeding assembly, an air feeding assembly, an ammonia-air mixer and a tail gas separator with a gas outlet; wherein,
the ammonia gas feeding assembly comprises an ammonia evaporator, an ammonia superheater and an ammonia filter which are sequentially communicated through an ammonia conveying pipeline, the output end of the ammonia filter is communicated with an ammonia gas inlet of the ammonia air mixer through an ammonia conveying pipeline, and an ammonia regulating valve and an ammonia emptying valve are sequentially arranged on the ammonia conveying pipeline connected between the ammonia superheater and the ammonia filter along the ammonia gas conveying direction;
the air feeding assembly comprises an air compressor and an air conveying pipeline connected with the output end of the air compressor and the air inlet of the ammonia-air mixer;
the double-pressurization method nitric acid production device further comprises a gas transmission pipeline, wherein one end of the gas transmission pipeline is connected with a gas outlet of the tail gas separator, and the other end of the gas transmission pipeline is connected to an ammonia transmission pipeline between the ammonia regulating valve and the ammonia superheater.
2. The apparatus for producing nitric acid by a double pressure method as set forth in claim 1, wherein a stop valve is provided on the gas transmission line.
3. The apparatus for producing nitric acid according to claim 1 or 2, wherein a flange is provided at the connection between the ammonia superheater and the ammonia delivery pipe.
4. The apparatus for producing nitric acid according to claim 3, wherein the flange is provided with a blind plate.
5. The double-pressurization nitric acid production device of claim 1 or 2, wherein the gas transmission pipeline is a DN200 pipeline.
6. The apparatus for producing nitric acid by a double pressurization method according to claim 1 or 2, wherein a three-way joint is provided on a gas discharge port of the tail gas separator; the first sub-interface of the three-way joint is connected with the gas outlet, the second sub-interface is connected to an ammonia conveying pipeline between the ammonia regulating valve and the ammonia superheater through the gas conveying pipeline, and the third sub-interface is used for discharging tail gas.
7. The apparatus for producing nitric acid according to claim 1 or 2, wherein the ammonia delivery pipe is further provided with an ammonia pressure gauge, an ammonia flow meter and an ammonia temperature gauge between the ammonia regulating valve and the ammonia vent valve.
8. The apparatus for producing nitric acid by the double pressure method according to claim 1 or 2, wherein an air vent valve, an air pressure gauge, an air temperature gauge and an air flow meter are arranged on the air conveying pipeline and are positioned between the air vent valve and the ammonia air mixer.
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| CN201410244264.1A CN105217585B (en) | 2014-06-04 | 2014-06-04 | Double pressurized method nitric acid production plant |
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| CN201410244264.1A CN105217585B (en) | 2014-06-04 | 2014-06-04 | Double pressurized method nitric acid production plant |
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| CN105217585B true CN105217585B (en) | 2017-06-23 |
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| CN105786055A (en) * | 2016-03-07 | 2016-07-20 | 重庆大学 | Control system and control method for ammonia-to-air ratio automatic set value in nitric acid production oxidation furnace |
| CN105883735A (en) * | 2016-05-13 | 2016-08-24 | 河南心连心化肥有限公司 | Oxygen-enriched-process nitric acid production device and nitric acid production method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10011335A1 (en) * | 2000-03-10 | 2001-09-20 | Krupp Uhde Gmbh | Production of nitric acid of specified concentration, useful in the production of adipic acid, caprolactam, toluene diisocyanate etc., by one- or 2-pressure combustion of ammonia and absorption uses dried air supply |
| CN201447362U (en) * | 2009-07-31 | 2010-05-05 | 山东联合化工股份有限公司 | Nitric acid production equipment system |
| CN202785660U (en) * | 2012-08-31 | 2013-03-13 | 安徽华尔泰化工股份有限公司 | Energy-saving type gaseous ammonia generating system for dilute nitric acid device |
| CN202898028U (en) * | 2012-11-14 | 2013-04-24 | 中国石油天然气股份有限公司 | Feeding system of device for producing nitric acid by oxidizing ammonia gas |
| CN204162423U (en) * | 2014-06-04 | 2015-02-18 | 贵州芭田生态工程有限公司 | Double pressurized method nitric acid production plant |
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- 2014-06-04 CN CN201410244264.1A patent/CN105217585B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10011335A1 (en) * | 2000-03-10 | 2001-09-20 | Krupp Uhde Gmbh | Production of nitric acid of specified concentration, useful in the production of adipic acid, caprolactam, toluene diisocyanate etc., by one- or 2-pressure combustion of ammonia and absorption uses dried air supply |
| CN201447362U (en) * | 2009-07-31 | 2010-05-05 | 山东联合化工股份有限公司 | Nitric acid production equipment system |
| CN202785660U (en) * | 2012-08-31 | 2013-03-13 | 安徽华尔泰化工股份有限公司 | Energy-saving type gaseous ammonia generating system for dilute nitric acid device |
| CN202898028U (en) * | 2012-11-14 | 2013-04-24 | 中国石油天然气股份有限公司 | Feeding system of device for producing nitric acid by oxidizing ammonia gas |
| CN204162423U (en) * | 2014-06-04 | 2015-02-18 | 贵州芭田生态工程有限公司 | Double pressurized method nitric acid production plant |
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