CN115448261B - A method for producing sulfuric acid by vacuum concentration of waste sulfuric acid - Google Patents
A method for producing sulfuric acid by vacuum concentration of waste sulfuric acid Download PDFInfo
- Publication number
- CN115448261B CN115448261B CN202210991606.0A CN202210991606A CN115448261B CN 115448261 B CN115448261 B CN 115448261B CN 202210991606 A CN202210991606 A CN 202210991606A CN 115448261 B CN115448261 B CN 115448261B
- Authority
- CN
- China
- Prior art keywords
- sulfuric acid
- temperature
- acid
- forced circulation
- valve
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B17/00—Sulfur; Compounds thereof
- C01B17/69—Sulfur trioxide; Sulfuric acid
- C01B17/88—Concentration of sulfuric acid
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
Abstract
本发明公开了一种废硫酸真空浓缩生产硫酸的方法，具体涉及化工技术领域，本发明通过采用双酸酸换热器回收热量，用伴热管系统预热搪玻璃管线，降低搪玻璃管线温度差低于100℃，保护搪玻璃管线，并且采用冷热酸混酸器，控制进入酸酸换热器的酸温，保证酸温度稳定上升，避免设备温度骤变损坏设备，采用液位‑流量控制联合控制技术，实现双进料，实现同时或者交替生产91％浓度96％浓度硫酸产品的自动控制连续运行，且整个过程操作简便，硫酸浓度由平均95.5％提高到平均96.2％，可以同时满足一硝基甲苯与多硝基甲苯两种产品生产的需要，降低生产成本，从而可以消除废硫酸真空浓缩装置刷洗的频繁停产问题，延长装置使用寿命。
The invention discloses a method for producing sulfuric acid by vacuum concentrating waste sulfuric acid, and specifically relates to the technical field of chemical industry. The invention adopts a double acid-acid heat exchanger to recover heat, uses a heat tracing pipe system to preheat a glass-lined pipeline, reduces the temperature difference of the glass-lined pipeline to less than 100 DEG C, protects the glass-lined pipeline, adopts a hot and cold acid mixer to control the acid temperature entering the acid-acid heat exchanger, ensures that the acid temperature rises steadily, avoids the equipment from being damaged by a sudden temperature change, adopts a liquid level-flow control combined control technology, realizes double feeding, realizes automatic control and continuous operation of simultaneously or alternately producing sulfuric acid products with a concentration of 91% and a concentration of 96%, and the whole process is simple to operate. The sulfuric acid concentration is increased from an average of 95.5% to an average of 96.2%, can meet the production needs of two products, mononitrotoluene and polynitrotoluene, and reduce the production cost, thereby eliminating the problem of frequent shutdowns due to brushing of a waste sulfuric acid vacuum concentrator and extending the service life of the device.
Description
Technical Field
The invention relates to the technical field of chemical industry, in particular to a method for producing sulfuric acid by vacuum concentration of waste sulfuric acid.
Background
In the production process of the mononitrotoluene production line and the common nitration production line, two specifications of waste sulfuric acid are generally produced, one set of waste sulfuric acid vacuum concentration treatment device is usually shared by the two specifications of waste sulfuric acid, the waste sulfuric acid can obtain concentrated sulfuric acid with the concentration of about 95.5% after being treated, the waste sulfuric acid vacuum concentration production device always produces concentrated sulfuric acid with the concentration of 95.5% to meet the use requirement of the sulfuric acid concentration of the two nitration production lines, and when the required concentration of finished sulfuric acid is 96%, the forced circulation section of the waste sulfuric acid vacuum concentration device for producing 96% sulfuric acid needs to be stopped and scrubbed for 1.5 days every 10 days, and the production is stopped for 30 times in a year.
At present, the waste sulfuric acid vacuum concentration treatment technology mainly comprises three steps, namely a treatment technology for introducing the high vacuum and high-end temperature of the German PLINKE company by spraying mononitrotoluene as an anticoagulant, a treatment technology for introducing the German DDPS company by cooling with warm water to prevent condensation, ultrahigh vacuum and low-end temperature (180-185 ℃), and a domestic waste sulfuric acid treatment technology, wherein the concentration of the sulfuric acid obtained by the device is 88-96.5%, and is usually 88% and 93% of the concentration specification.
The above-described processing apparatus and method have the following problems in practical use:
1. The production line of mononitrotoluene generally uses concentrated sulfuric acid with concentration of more than 88% to meet the requirement of nitration production, and the production line of mononitrotoluene uses sulfuric acid with concentration of 96% to carry out nitration, so that on one hand, the concentration of sulfuric acid is excessive, on the other hand, the local ¢ value in the nitration process is too high, the nitration is easy to occur, the dinitrotoluene content in mononitrotoluene is not easy to control, and the rectification separation cost of mononitrotoluene is increased;
2. The equipment can only produce concentrated sulfuric acid with a certain concentration at the same time, and the waste sulfuric acid vacuum concentration treatment device is difficult to produce sulfuric acid with a concentration of more than 96%, generally keeps a concentration of about 95.5% stably, and when the required sulfuric acid concentration is higher than 95.5%, a section of heat conducting oil concentration device is added on the basis of the 96% concentration waste sulfuric acid vacuum concentration device, so that the production cost is increased sharply;
3. The waste sulfuric acid vacuum concentration device produces sulfuric acid with concentration of more than 91 percent, and the production cost is increased by more than 20 percent compared with 96 percent sulfuric acid, so that the production cost is greatly increased;
4. The forced circulation section of the waste sulfuric acid vacuum concentration device for producing 96% sulfuric acid needs to be stopped and scrubbed for 1.5 days every 10 days, production is stopped for 30 times every year, frequent start and stop cause device damage, scrubbing and scrubbing are needed for 45 days every year, and the production capacity of the waste sulfuric acid vacuum concentration device is seriously reduced.
In view of this, it is important to develop a new method for producing sulfuric acid by vacuum concentration of waste sulfuric acid to solve the above problems.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a method for producing sulfuric acid by vacuum concentration of waste sulfuric acid, and the technical problems that a set of waste sulfuric acid treatment equipment in the prior art only can produce concentrated sulfuric acid with a certain concentration simultaneously, the production of sulfuric acid with a concentration of more than 96% is difficult to realize, the production cost also increases sharply, and the production capacity of a waste sulfuric acid vacuum concentration device is seriously reduced because the waste sulfuric acid treatment equipment needs to be scrubbed and scrubbed for 45 days each year during the production of two kinds of sulfuric acid.
The method for producing sulfuric acid by vacuum concentration of waste sulfuric acid comprises a waste sulfuric acid treatment device, wherein the waste sulfuric acid treatment device comprises a first acid heat exchanger, connecting pipelines on the right sides of the first acid heat exchanger and a second acid heat exchanger are connected to the left upper side of a denitration tower, the upper side of the denitration tower is connected with a gas pipeline, the right lower side of the denitration tower is connected to the left lower side of a secondary concentrator, the right upper side of the secondary concentrator is connected with a secondary gas phase processor, and the right lower side of the secondary concentrator is connected with a high-temperature sulfuric acid tank.
The high-temperature sulfuric acid tank is characterized in that the right side of the high-temperature sulfuric acid tank is connected with a high-temperature hand pump, the right side of the high-Wen Zhuai hand pump is connected with a first high-temperature automatic regulating valve, the upper side of the first high-temperature automatic regulating valve is connected with a first high-temperature pipeline, the first high-temperature pipeline is a glass lining pipe, the left side of the first high-temperature pipeline is connected with a fourth temperature transmitter, the right side and the upper side of the first high-temperature pipeline are provided with heat tracing pipes, and the left side of the heat tracing pipes is connected to the acid mixing tank.
The lower side of the mixed acid tank is connected with a second acid heat exchanger, the lower side of the second acid heat exchanger is connected with a low-temperature sulfuric acid tank, the left lower side of the low-temperature sulfuric acid tank is connected with a low-temperature sulfuric acid pump, and the right side of the low-temperature sulfuric acid pump is connected with a second cooler.
The right side of the high-temperature hand rotating pump is connected with a second high-temperature automatic regulating valve, the upper side of the second high-temperature automatic regulating valve is connected with a second high-temperature pipeline, the upper left side of the second high-temperature pipeline is connected with a forced circulation heater, the upper left side of the forced circulation heater is respectively connected with a second temperature transmitter and a forced circulation flash evaporator, the lower side of the forced circulation flash evaporator is connected with a forced circulation pump, and the upper left side of the forced circulation flash evaporator is connected with a forced circulation gas phase processor.
The left lower side of the forced circulation flash evaporator is connected with a third high-temperature pipeline, the lower side of the third high-temperature pipeline is connected with a first acid-acid heat exchanger, the lower side of the first acid-acid heat exchanger is connected with a hand turning groove, and the left lower side of the third automatic regulating valve is connected with a first hand turning pump.
The method for vacuum concentration treatment of the waste sulfuric acid comprises the following steps:
S1, filling device materials.
S2, the device establishes vacuum.
S3, preheating and heating the device.
S4, feeding waste sulfuric acid and producing 96% concentration sulfuric acid.
S5, producing 91% sulfuric acid.
S6, automatic control of the device operation.
S7, brushing the device in a forced circulation section without stopping.
S8, reproduction of the forced circulation section without stopping the device.
The invention further provides a scheme that the left side of the first acid-acid heat exchanger is connected with a second waste sulfuric acid flowmeter, and the left side of the second waste sulfuric acid flowmeter is connected with a second automatic regulating valve.
The left side of the second acid heat exchanger is connected with a first waste sulfuric acid flowmeter, the left side of the first waste sulfuric acid flowmeter is connected with a first automatic regulating valve, and the left sides of the second automatic regulating valve and the first automatic regulating valve are connected to a waste sulfuric acid feeding pipe through pipelines.
The upper right side of the secondary concentrator is connected with a first pressure transmitter, the lower left side of the secondary concentrator is connected with a first temperature transmitter, the upper side of the high-temperature sulfuric acid tank is connected with a third liquid level meter, and the left side of the secondary concentrator is connected with a second starting valve.
The left side of the mixed acid tank is connected with a third temperature transmitter, the right lower side of the mixed acid tank is connected with a mixed acid valve, a pipeline at the left lower side of the low-temperature sulfuric acid pump is connected with a second scrubbing valve, and the right side of the low-temperature sulfuric acid pump is respectively connected with a low-temperature automatic regulating valve and the mixed acid valve.
As a further scheme of the invention, the upper side of the low-temperature sulfuric acid tank is connected with a first liquid level meter.
The right side of the second cooler is connected to the left side of the low-temperature automatic regulating valve, the right side of the low-temperature automatic regulating valve is connected with the low-temperature flowmeter, the low-temperature flowmeter is in signal association with the first high-temperature automatic regulating valve, and the second automatic regulating valve is in signal association with the third liquid level meter.
The left lower side of the forced circulation pump is connected with a first brushing valve, and the left upper side of the forced circulation flash evaporator is connected with a second pressure transmitter.
The upper right side of the forced circulation gas phase processor is respectively connected with a vacuum breaking valve and a switching valve, the left side of the switching valve is connected with a first vacuum pump, the left side of the first vacuum pump is connected to the left side of the secondary gas phase processor, and the upper right side of the secondary gas phase processor is connected with a second vacuum pump.
The upper side of the hand turning groove is connected with a second liquid level meter, the upper right side of the hand turning groove is connected with a third automatic regulating valve, and the second liquid level meter is in signal association with the third automatic regulating valve.
The left lower side of the first hand pump is connected with a third brushing valve, the right lower side of the third automatic regulating valve is connected with a first starting valve, and the right side of the first starting valve is connected with a second starting valve.
The invention further provides a concrete method for filling the device with materials, which comprises the following steps:
And filling 91% sulfuric acid into the first acid heat exchanger, the second acid heat exchanger, the hand turning tank, the first cooler, the first hand turning pump, the low-temperature sulfuric acid tank, the low-temperature sulfuric acid pump, the denitration tower, the secondary concentrator, the high-temperature sulfuric acid tank, the high-temperature hand turning pump, the forced circulation heater, the forced circulation pump and the forced circulation flash evaporator through the second automatic regulating valve, the first automatic regulating valve and related pipelines, and sealing the equipment to establish high-vacuum isolated air.
The specific method for establishing vacuum by the device comprises the following steps:
The first vacuum pump and the second vacuum pump are started, the value of the first pressure transmitter is between 6.5KPa and 8.5KPa, and the value of the second pressure transmitter is between 1.1KPa and 1.2KPa.
As a further scheme of the invention, the specific method for preheating and heating the device comprises the following steps:
The first starting valve and the second starting valve are opened, the forced circulation pump, the forced circulation flash evaporator and the connecting pipeline are started to perform forced circulation, and meanwhile, the first hand-rotating pump, the low-temperature sulfuric acid pump and the high-temperature hand-rotating pump are started, so that 91 percent sulfuric acid circulates to the high-temperature sulfuric acid tank from the high-temperature sulfuric acid tank through the second high-temperature automatic regulating valve, the forced circulation heater, the forced circulation flash evaporator, the third high-temperature pipeline, the first acid heat exchanger, the hand-rotating tank, the first cooler, the first starting valve and the second starting valve, the denitration tower is heated to 90-100 ℃, the secondary concentrator is heated to 120-130 ℃, and the forced circulation heater, the forced circulation pump and the forced circulation flash evaporator are heated to 120-130 ℃ so that the thermal shock temperature of the device is lower than 70 ℃.
As a further scheme of the invention, the concrete method for producing 96% concentration sulfuric acid by feeding the waste sulfuric acid comprises the following steps:
Closing the first starting valve and the second starting valve, opening the second automatic regulating valve, metering the waste sulfuric acid by a second waste sulfuric acid flowmeter, then feeding the waste sulfuric acid into a first acid heat exchanger, a denitration tower, a secondary concentrator and a high-temperature sulfuric acid tank, feeding the waste sulfuric acid into a forced circulation system consisting of a forced circulation pump, a forced circulation flash evaporator and a forced circulation gas-phase processor by a second high-temperature automatic regulating valve and a second high-temperature pipeline, feeding the concentrated sulfuric acid into a hand turning tank after exchanging heat with the waste sulfuric acid by a third high-temperature pipeline, and feeding the waste sulfuric acid into a finished product tank after being cooled to below 40 ℃ by the first hand turning pump and a first cooler.
The second automatic regulating valve is regulated to enable the flow of the measured waste sulfuric acid to be gradually increased through the second waste sulfuric acid flowmeter, the increasing amount is less than or equal to 1m 3/h every 30 minutes, the temperature of the denitration tower is gradually increased, the value of the first temperature transmitter of the secondary concentrator is increased to 185-187 ℃, and the value of the temperature transmitter at the outlet of the forced circulation heater is increased to 182-185 ℃.
As a further scheme of the invention, the specific steps for producing 91% concentration sulfuric acid are as follows:
s51, starting the heat tracing pipe, and heating the first high-temperature pipeline to the temperature of 100-120 ℃ of the temperature transmitter.
S52, opening an acid mixing valve, enabling the cold 91% sulfuric acid from the second cooler to enter an acid mixing tank, enabling the cold 91% sulfuric acid to enter a low-temperature sulfuric acid tank through a second acid heat exchanger, and enabling the cold 91% sulfuric acid to circulate to the second cooler through a low-temperature sulfuric acid pump.
And S53, setting the value of the first liquid level meter to be 50%, setting the value of the low-temperature flowmeter according to the product quantity requirement, correlating the value signal with the first high-temperature automatic regulating valve, slowly regulating the opening of the mixed acid valve, controlling the value of the third temperature transmitter of the mixed acid tank, and closing the mixed acid valve when the value reaches 100 ℃.
S54, calculating and setting the value of the first waste sulfuric acid flowmeter according to the value of the low-temperature flowmeter, wherein the value of the first waste sulfuric acid flowmeter is related to the first automatic regulating valve.
S55, the 91% sulfuric acid is cooled to below 40 ℃ by a second cooler and then discharged into a 91% sulfuric acid storage tank.
As a further aspect of the invention, the automatic control of the operation of the device comprises the following methods:
According to the requirement of the waste sulfuric acid treatment capacity, setting the value of a second waste sulfuric acid flowmeter, wherein the value of the second waste sulfuric acid flowmeter is related to a second automatic regulating valve, the liquid level of a third liquid level meter of a high-temperature sulfuric acid tank is set to be 50%, the third liquid level meter is related to the second high-temperature automatic regulating valve, 91% high-temperature sulfuric acid enters a forced circulation heater, a forced circulation pump and a forced circulation flash evaporator according to the liquid level, the system is concentrated to 96% sulfuric acid, 96% sulfuric acid enters a hand turning tank through a first acid heat exchanger, the second liquid level meter is set to be 50%, the second liquid level meter is related to the third automatic regulating valve, and 96% sulfuric acid is discharged into a 96% sulfuric acid storage tank after being cooled to below 40 ℃ through a first cooler.
The invention further provides a specific method for brushing the non-stop forced circulation section of the device, which comprises the following steps:
When the forced circulation system consisting of the forced circulation heater, the forced circulation pump, the forced circulation flash evaporator, the first acid-acid heat exchanger, the hand rotating tank, the first cooler and the first hand rotating pump is required to be scrubbed, the system required to be scrubbed is stopped, the first vacuum pump and the switch valve are closed, the vacuum breaking valve is opened, sulfuric acid in the system is cleaned by the first scrubbing valve and the third scrubbing valve, the scrubbing water is injected through the first scrubbing valve and the third scrubbing valve for scrubbing, and after the scrubbing is finished, the scrubbing water is cleaned by the first scrubbing valve and the third scrubbing valve, so that the scrubbing is completed.
As a further scheme of the invention, the device comprises the following specific methods of reproduction of the forced circulation section without stopping the device:
injecting cold 91% sulfuric acid through the first brushing valve and the third brushing valve, closing the vacuum breaking valve, opening the switching valve and the first vacuum pump until the value of the second pressure transmitter reaches 1.2KPa, slowly starting the forced circulation heater, the forced circulation pump and the forced circulation flash evaporator system, controlling the temperature rising value of the second temperature transmitter to be less than or equal to 1 ℃ per minute until the temperature value of the second temperature transmitter reaches more than 180 ℃, and opening the second high-temperature automatic regulating valve, the forced circulation heater, the forced circulation pump and the forced circulation flash evaporator to enable the system to be switched into normal operation.
The invention has the beneficial effects that:
according to the invention, a double-acid heat exchanger is adopted to recover heat, a heat tracing pipe system is used to preheat a glass lining pipeline, the temperature difference of the glass lining pipeline is reduced to be lower than 100 ℃, the glass lining pipeline is protected, a cold-hot acid mixer is adopted to control the acid temperature entering the acid-acid heat exchanger, the stable rising of the acid temperature is ensured, the equipment temperature is prevented from suddenly changing and damaging the equipment, the liquid level-flow control combined control technology is adopted to realize double feeding, automatic control continuous operation of simultaneously or alternately producing 91% concentration 96% concentration sulfuric acid products is realized, the whole process is simple and convenient to operate, the sulfuric acid concentration is improved from 95.5% on average to 96.2% on average, the production requirements of mononitrotoluene and polynitrotoluene can be simultaneously met, the production cost is reduced, the frequent production stopping problem of scrubbing of a waste sulfuric acid vacuum concentration device can be eliminated, and the service life of the device is prolonged;
The invention solves the problems of discontinuous production, high equipment failure rate and reduced production capacity of the device caused by scaling and frequent scrubbing of ferric sulfate salt of the waste sulfuric acid vacuum concentration device, and ensures that the waste sulfuric acid vacuum concentration device can increase the production capacity by 15 percent, thereby improving the profitability of the upstream nitrified products and achieving the annual comprehensive economic benefit of more than 500 ten thousand yuan.
Drawings
FIG. 1 is a schematic diagram of the apparatus used in the process for producing spent sulfuric acid according to the present invention;
In the figure, 1, a first acid heat exchanger; 2, a second acid heat exchanger; 3, turning the hand groove; the system comprises a first cooler, a first hand pump, a low-temperature sulfuric acid tank, a first cooler, a second cooler, a low-temperature sulfuric acid pump, a second cooler, a high-temperature sulfuric acid tank, a high-temperature pipeline, a high-temperature hand pump, a forced circulation heater, a forced circulation pump, a forced circulation flash evaporator, a forced circulation gas phase processor, a first pressure transducer, a second pressure transducer, a third pressure transducer, a fourth pressure transducer, a vacuum transducer, and a vacuum, respectively, wherein the vacuum transducer, and the vacuum transducer and the vacuum pump and the vacuum and vacuum.
Detailed Description
The following description of the technical solutions in the embodiments of the present invention will be clear and complete, and it is obvious that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The method for producing sulfuric acid by vacuum concentration of waste sulfuric acid comprises a waste sulfuric acid treatment device, wherein the waste sulfuric acid treatment device comprises a first acid heat exchanger 1, right side connecting pipelines of the first acid heat exchanger 1 and a second acid heat exchanger 2 are connected to the left upper side of a denitration tower 41, the upper side of the denitration tower 41 is connected with a gas pipeline, the right lower side of the denitration tower 41 is connected to the left lower side of a secondary concentrator 9, the right upper side of the secondary concentrator 9 is connected with a secondary gas phase processor 10, and the right lower side of the secondary concentrator 9 is connected with a high-temperature sulfuric acid tank 11.
The right side of the high-temperature sulfuric acid tank 11 is connected with the high Wen Zhuaishou pump 12, the right side of the high Wen Zhuaishou pump 12 is connected with the first high-temperature automatic regulating valve 24, the upper side of the first high-temperature automatic regulating valve 24 is connected with the first high-temperature pipeline 26, the first high-temperature pipeline 26 is a glass lining pipe, the left side of the first high-temperature pipeline 26 is connected with the fourth temperature transmitter 47, the right side and the upper side of the first high-temperature pipeline 26 are provided with the heat tracing pipe 48, the left side of the heat tracing pipe 48 is connected to the acid mixing tank 45, the heat tracing pipe 48 is used for heating the cold glass lining pipe to 100-120 ℃ through the heat tracing pipe 48, the first high-temperature pipeline 26 is used for suddenly conveying 180 ℃ sulfuric acid, the first high-temperature pipeline 26 is not exploded by thermal shock, the acid mixing tank 45, the first high-temperature pipeline 26 and the acid mixing valve 44 form an acid mixing system, the 91% sulfuric acid temperature in the acid mixing tank 45 is slowly and stably increased, and the second acid heat exchanger 2 is prevented from being damaged by thermal shock.
The lower side of the mixed acid tank 45 is connected with the second acid heat exchanger 2, the lower side of the second acid heat exchanger 2 is connected with the low-temperature sulfuric acid tank 6, the left lower side of the low-temperature sulfuric acid tank 6 is connected with the low-temperature sulfuric acid pump 8, the right side of the low-temperature sulfuric acid pump 8 is connected with the second cooler 7, and the low-temperature sulfuric acid tank 6, the second cooler 7, the low-temperature sulfuric acid pump 8, the mixed acid tank 45, the first high-temperature automatic regulating valve 24, the connecting pipeline, the first pressure transmitter 31, the first temperature transmitter 32, the second pressure transmitter 33, the second temperature transmitter 34, the third temperature transmitter 46 and the fourth temperature transmitter 47 form a 91% sulfuric acid product system for simultaneously producing 91% sulfuric acid.
The right side of the high-temperature hand rotating pump 12 is connected with a second high-temperature automatic regulating valve 25, the upper side of the second high-temperature automatic regulating valve 25 is connected with a second high-temperature pipeline 27, the upper side of the second high-temperature pipeline 27 is connected with a forced circulation heater 13, the left upper side of the forced circulation heater 13 is respectively connected with a second temperature transmitter 34 and a forced circulation flash evaporator 15, the lower side of the forced circulation flash evaporator 15 is connected with a forced circulation pump 14, the left upper side of the forced circulation flash evaporator 15 is connected with a forced circulation gas-phase processor 16, and the forced circulation heater 13, the forced circulation pump 14, the forced circulation flash evaporator 15, the first acid heat exchanger 1, the hand rotating tank 3, the first cooler 4 and the first hand rotating pump 5 form a forced circulation system for producing 96% sulfuric acid.
The left lower side of the forced circulation flash evaporator 15 is connected with a third high-temperature pipeline 28, the lower side of the third high-temperature pipeline 28 is connected with the first acid-acid heat exchanger 1, the lower side of the first acid-acid heat exchanger 1 is connected with the hand rotating tank 3, and the left lower side of the third automatic regulating valve 30 is connected with the first hand rotating pump 5.
The left side of the first acid heat exchanger 1 is connected with a second waste sulfuric acid flowmeter 20, and the left side of the second waste sulfuric acid flowmeter 20 is connected with a second automatic regulating valve 19.
The left side of the second acid heat exchanger 2 is connected with a first waste sulfuric acid flowmeter 18, the left side of the first waste sulfuric acid flowmeter 18 is connected with a first automatic regulating valve 17, and the left sides of the second automatic regulating valve 19 and the first automatic regulating valve 17 are connected to a waste sulfuric acid feeding pipe through pipelines.
The upper right side of the secondary concentrator 9 is connected with a first pressure transmitter 31, the lower left side is connected with a first temperature transmitter 32, the upper side of the high-temperature sulfuric acid tank 11 is connected with a third liquid level meter 49, the left side is connected with a second starting valve 43, the third liquid level meter 49 feeds back a liquid level signal to a second high-temperature automatic regulating valve 25 of a 96% end section from an outlet of a high Wen Zhuaishou pump 12, the second high-temperature automatic regulating valve 25 automatically regulates 91% sulfuric acid quantity of the 96% end section according to a set liquid level, the second liquid level meter 29 feeds back a liquid level signal to a third automatic regulating valve 30, the third automatic regulating valve 30 automatically regulates according to a liquid level set value, waste sulfuric acid from the second automatic regulating valve 19 exchanges heat with high-temperature 96% sulfuric acid to recover heat, the flow value of the second waste sulfuric acid flowmeter 20 is set according to a 96% sulfuric acid flow value conversion of a product, the flow signal of the second waste sulfuric acid flowmeter 20 is fed back to the second automatic regulating valve 19, and 96% sulfuric acid product production is automatically completed.
The third temperature transmitter 46 is connected to the left side of mixing acid tank 45, and mix sour valve 44 is connected to the lower right side, and low temperature sulfuric acid pump 8 left side downside pipeline is connected second scrubbing valve 36, and low temperature automatically regulated valve 22 and mix sour valve 44 are connected respectively to the right side.
The upper side of the low-temperature sulfuric acid tank 6 is connected with a first liquid level meter 21.
The right side of the second cooler 7 is connected to the left side of the low-temperature automatic regulating valve 22, the right side of the low-temperature automatic regulating valve 22 is connected with the low-temperature flowmeter 23, the low-temperature flowmeter 23 is in signal association with the first high-temperature automatic regulating valve 24, the automatic regulating valve II is in signal association with the third liquid level meter 49, the low-temperature flowmeter 23 is provided with a flow value, the flow signal is fed back to the first high-temperature automatic regulating valve 24, the automatic regulating valve automatically regulates, the first liquid level meter 21 feeds back the liquid level signal to the low-temperature automatic regulating valve 22, the low-temperature automatic regulating valve 22 automatically regulates according to a liquid level set value, heat exchange recovery heat is carried out between waste sulfuric acid from the first automatic regulating valve 17 and hot 91% sulfuric acid, a waste acid first waste sulfuric acid flowmeter 18 flow value is converted according to a product 91% sulfuric acid flow value, and the waste acid first waste sulfuric acid flowmeter 18 flow signal is fed back to the first automatic regulating valve 17, and the production of 91% sulfuric acid product is automatically completed.
The lower left side of the forced circulation pump 14 is connected with a first brushing valve 35, and the upper left side of the forced circulation flash evaporator 15 is connected with a second pressure transmitter 33.
The upper right side of the forced circulation gas phase processor 16 is respectively connected with a vacuum breaking valve 50 and a switching valve 38, the left side of the switching valve 38 is connected with a first vacuum pump 39, the left side of the first vacuum pump 39 is connected with the left side of the secondary gas phase processor 10, and the upper right side of the secondary gas phase processor 10 is connected with a second vacuum pump 40.
The upper side of the hand turning groove 3 is connected with a second liquid level meter 29, the upper right side is connected with a third automatic regulating valve 30, and the second liquid level meter 29 is in signal association with the third automatic regulating valve 30.
The left lower side of the first hand pump 5 is connected with a third brushing valve 37, the right lower side of the third automatic regulating valve 30 is connected with a first starting valve 42, and the right side of the first starting valve 42 is connected with a second starting valve 43.
Examples
The method for vacuum concentration treatment of the waste sulfuric acid comprises the following steps:
S1, filling device materials, namely filling 91% concentration sulfuric acid into a first acid heat exchanger 1, a second acid heat exchanger 2, a hand turning tank 3, a first cooler 4, a first hand turning pump 5, a low-temperature sulfuric acid tank 6, a low-temperature sulfuric acid pump 8, a denitration tower 41, a secondary concentrator 9, a high-temperature sulfuric acid tank 11, a high-temperature hand turning pump 12, a forced circulation heater 13, a forced circulation pump 14 and a forced circulation flash evaporator 15 through a second automatic regulating valve 17 and related pipelines, and performing equipment sealing to establish high vacuum air isolation.
S2, the device establishes vacuum, namely, the first vacuum pump 39 and the second vacuum pump 40 are started, the value of the first pressure transmitter 31 is 6.5KPa-8.5KPa, and the value of the second pressure transmitter 33 is 1.1KPa-1.2KPa.
S3, preheating and heating the device, namely opening a first starting valve 42 and a second starting valve 43, starting a forced circulation pump 14 and a forced circulation heater 13, forcibly circulating the forced circulation pump 14, a forced circulation flash evaporator 15 and connecting pipelines, simultaneously starting a first hand pump 5, a low-temperature sulfuric acid pump 8 and a high-temperature hand pump 12, enabling 91% sulfuric acid to circulate to the high-temperature sulfuric acid tank 11 from the high-temperature sulfuric acid tank 3, the first cooler 4, the first starting valve 42 and the second starting valve 43 through a second high-temperature automatic regulating valve 25, the forced circulation heater 13, the forced circulation flash evaporator 15, a third high-temperature pipeline 28, and the first acid heat exchanger 1, the hand tank 11, and heating the denitration tower 41 to 90-100 ℃, and heating the secondary concentrator 9 to 120-130 ℃, wherein the forced circulation heater 13, the forced circulation pump 14 and the forced circulation flash evaporator 15 are all heated to 120-130 ℃, and the thermal shock temperature of the device is lower than 70 ℃. .
S4, feeding waste sulfuric acid and producing 96% concentration sulfuric acid, namely closing a first starting valve 42 and a second starting valve 43, opening a second automatic regulating valve 19, metering the waste sulfuric acid by a second waste sulfuric acid flowmeter 20, feeding the waste sulfuric acid into a first acid heat exchanger 1, a denitration tower 41, a secondary concentrator 9 and a high-temperature sulfuric acid tank 11, feeding the waste sulfuric acid into a forced circulation system consisting of a forced circulation pump 14, a forced circulation flash evaporator 15 and a forced circulation gas phase processor 16 by a second high-temperature automatic regulating valve 25 and a second high-temperature pipeline 27, feeding the concentrated sulfuric acid into a hand-turning tank 3 after heat exchange between the concentrated sulfuric acid and the waste sulfuric acid by a third high-temperature pipeline 28, cooling the waste sulfuric acid to below 40 ℃ by a first hand-turning pump 5 and a first cooler 4, and feeding the concentrated sulfuric acid into a finished product tank area.
The second automatic regulating valve 19 is regulated to gradually increase the flow rate of the waste sulfuric acid measured by the second waste sulfuric acid flowmeter 20, the increment is less than or equal to 1m < 3 >/h every 30 minutes, the temperature of the denitration tower 41 is gradually increased, the value of the first temperature transmitter 32 of the secondary concentrator 9 is increased to 185-187 ℃, and the value of the temperature transmitter at the outlet of the forced circulation heater 13 is increased to 182-185 ℃.
S5, producing 91% sulfuric acid, S51, starting the heat tracing pipe 48, and heating the first high-temperature pipeline 26 to the temperature of 100-120 ℃ as the value of the temperature transmitter.
S52, opening the mixed acid valve 44, enabling the cold 91% sulfuric acid from the second cooler 7 to enter the mixed acid tank 45, enabling the cold 91% sulfuric acid to enter the low-temperature sulfuric acid tank 6 through the second acid heat exchanger 2, and enabling the cold 91% sulfuric acid to circulate to the second cooler 7 through the low-temperature sulfuric acid pump 8.
S53, setting the value of the first liquid level meter 21 to be 50%, setting the value of the low-temperature flowmeter 23 according to the product quantity, correlating the value signal with the first high-temperature automatic regulating valve 24, slowly regulating the opening of the mixed acid valve 44, controlling the value of the third temperature transmitter 46 of the mixed acid tank 45, and closing the mixed acid valve 44 when the value reaches 100 ℃.
S54, calculating and setting the value of the first waste sulfuric acid flow meter 18 according to the value of the low-temperature flow meter 23, wherein the value of the first waste sulfuric acid flow meter 18 is related to the first automatic regulating valve 17.
S55, 91% sulfuric acid is cooled to below 40 ℃ by a second cooler 7 and then discharged into a 91% sulfuric acid storage tank.
S6, automatic control of device operation, namely setting a value of a second waste sulfuric acid flowmeter 20 according to the requirement of waste sulfuric acid treatment capacity, setting the value of the second waste sulfuric acid flowmeter 20 to be related to a second automatic regulating valve 19, setting the liquid level of a third liquid level meter 49 of a high-temperature sulfuric acid tank 11 to be 50%, setting the liquid level of the third liquid level meter 49 to be related to a second high-temperature automatic regulating valve 25, automatically regulating high-temperature 91% sulfuric acid to enter a forced circulation heater 13, a forced circulation pump 14 and a forced circulation flash evaporator 15 according to the liquid level, concentrating the system to 96% sulfuric acid, enabling 96% sulfuric acid to enter a hand turning tank 3 through a first acid heat exchanger 1, setting the second liquid level meter 29 to be 50%, setting the second liquid level meter 29 to be related to a signal of the third automatic regulating valve 30,96% sulfuric acid to be cooled to below 40 ℃ through a first cooler 4, and discharging the sulfuric acid to a 96% sulfuric acid storage tank.
S7, the device does not stop the forced circulation section for brushing, namely when a forced circulation system consisting of the forced circulation heater 13, the forced circulation pump 14, the forced circulation flash evaporator 15, the first acid heat exchanger 1, the hand rotating tank 3, the first cooler 4 and the first hand rotating pump 5 is required to be brushed, the system required to be brushed is stopped, the first vacuum pump 39 and the switch valve 38 are closed, the vacuum breaking valve 50 is opened, sulfuric acid in the system is discharged from the first brushing valve 35 and the third brushing valve 37, brushing water is injected through the first brushing valve 35 and the third brushing valve 37 for brushing, and after brushing is finished, the cleaning water is discharged through the first brushing valve 35 and the third brushing valve 37, so that brushing is finished.
S8, the device is in the regeneration of a non-stop forced circulation section, namely cold 91% sulfuric acid is injected through a first brushing valve 35 and a third brushing valve 37, a vacuum breaking valve 50 is closed, a switching valve 38 and a first vacuum pump 39 are opened until the value of a second pressure transmitter 33 reaches 1.2KPa, a forced circulation heater 13, a forced circulation pump 14 and a forced circulation flash evaporator 15 system are slowly started, the temperature rising value of the second temperature transmitter 34 is controlled to be less than or equal to 1 ℃ per minute until the temperature value of the second temperature transmitter 34 reaches more than 180 ℃, and a second high-temperature automatic regulating valve 25, the forced circulation heater 13, the forced circulation pump 14 and the forced circulation flash evaporator 15 are opened, so that the system is switched into normal operation.
Examples
The low-temperature flowmeter 23 is provided with a flow value, a flow signal is fed back to the first high-temperature automatic regulating valve 24, the automatic regulating valve is used for automatic regulation, the first liquid level meter 21 feeds back a liquid level signal to the low-temperature automatic regulating valve 22, the low-temperature automatic regulating valve 22 is used for automatic regulation according to a liquid level set value, the waste sulfuric acid from the first automatic regulating valve 17 exchanges heat with hot 91% concentration sulfuric acid to recover heat, the flow value of the waste acid first waste sulfuric acid flowmeter 18 is converted and set according to the flow value of 91% sulfuric acid of the product, and the flow signal of the waste acid first waste sulfuric acid flowmeter 18 is fed back to the first automatic regulating valve 17, so that the production of 91% sulfuric acid products is automatically completed.
Examples
The third liquid level meter 49 feeds back a liquid level signal to the second high-temperature automatic regulating valve 25 from the outlet of the high Wen Zhuaishou pump 12 to the 96% end section, the second high-temperature automatic regulating valve 25 automatically regulates the 91% sulfuric acid amount of the 96% end section according to the set liquid level, the second liquid level meter 29 feeds back the liquid level signal to the third automatic regulating valve 30, the third automatic regulating valve 30 automatically regulates according to the liquid level set value, the waste sulfuric acid from the second automatic regulating valve 19 exchanges heat with the high-temperature 96% concentration sulfuric acid to recover heat, the flow value of the second waste sulfuric acid flowmeter 20 is converted and set according to the 96% sulfuric acid flow value of the product, and the flow signal of the second waste sulfuric acid flowmeter 20 is fed back to the second automatic regulating valve 19 to automatically finish the production of the 96% sulfuric acid product.
Examples
When the forced circulation system of 96% sulfuric acid consisting of the forced circulation heater 13, the forced circulation pump 14, the forced circulation flash evaporator 15, the first acid-acid heat exchanger 1, the hand turning tank 3, the first cooler 4 and the first hand turning pump 5 is required to be scrubbed, the system required to be scrubbed is stopped, the first vacuum pump 39 and the switch valve 38 are closed, the vacuum breaking valve 50 is opened, 91% sulfuric acid products are continuously produced, the forced circulation system is scrubbed, and the waste sulfuric acid vacuum concentration device continuously processes the waste sulfuric acid.
Examples
When the production of 96% concentration sulfuric acid needs to be restored, cold 91% sulfuric acid is injected through the first brushing valve 35 and the third brushing valve 37, the vacuum breaking valve 50 is closed, the switch valve 38 and the first vacuum pump 39 are opened until the value of the second pressure transmitter 33 reaches 1.2KPa, the forced circulation heater 13, the forced circulation pump 14 and the forced circulation flash evaporator 15 system are slowly started, the temperature rising value of the second temperature transmitter 34 is controlled to be less than or equal to 1 ℃ per minute, the temperature value of the second temperature transmitter 34 reaches more than 180 ℃, the second high-temperature automatic regulating valve 25 is opened, and the waste sulfuric acid forced circulation system is enabled to restore the production of 96% concentration sulfuric acid.
In summary, the invention adopts the double acid heat exchanger to recycle heat, uses the heat tracing pipe 48 system to preheat the glass lining pipeline, reduces the temperature difference of the glass lining pipeline to be lower than 100 ℃, protects the glass lining pipeline, adopts the cold and hot acid mixer to control the acid temperature entering the acid heat exchanger, ensures the stable rising of the acid temperature, avoids the sudden change of the equipment temperature and damages the equipment, adopts the liquid level-flow control combined control technology to realize double feeding, realizes the automatic control continuous operation of simultaneously or alternately producing the sulfuric acid product with the concentration of 91 percent and 96 percent, has simple and convenient operation in the whole process, improves the sulfuric acid concentration from average 95.5 percent to average 96.2 percent, can simultaneously meet the production requirements of the two products of mononitrotoluene and polynitrotoluene, reduces the production cost, thereby eliminating the frequent production stopping problem of scrubbing of the waste sulfuric acid vacuum concentration device, prolonging the service life of the device, and simultaneously realizing the simultaneous production of 91 percent sulfuric acid and more than 96 percent sulfuric acid in the waste sulfuric acid vacuum concentration treatment device, or the continuous and alternately producing the sulfuric acid with the concentration of 91 percent and 96 percent sulfuric acid.
The problems of discontinuous production, high equipment failure rate and reduced production capacity of the device caused by scaling and frequent scrubbing of ferric sulfate salt of the waste sulfuric acid vacuum concentration device are solved, and the production capacity of the waste sulfuric acid vacuum concentration device can be increased by 15%, so that the profitability of an upstream nitrified product is improved, and the annual comprehensive economic benefit reaches more than 500 ten thousand yuan.
It should be noted that, although the present invention has been described in detail by way of general description and specific embodiments, the above embodiments are merely illustrative and not restrictive, and although the present invention has been described in detail by way of reference to the above embodiments, it should be understood by those skilled in the art that the technical solutions described in the above embodiments may be modified or some or all of the technical features may be equivalently replaced, and these modifications or substitutions do not depart from the spirit of the technical solutions of the embodiments of the present invention.
Claims (9)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210991606.0A CN115448261B (en) | 2022-08-18 | 2022-08-18 | A method for producing sulfuric acid by vacuum concentration of waste sulfuric acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210991606.0A CN115448261B (en) | 2022-08-18 | 2022-08-18 | A method for producing sulfuric acid by vacuum concentration of waste sulfuric acid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115448261A CN115448261A (en) | 2022-12-09 |
| CN115448261B true CN115448261B (en) | 2025-02-07 |
Family
ID=84299183
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210991606.0A Active CN115448261B (en) | 2022-08-18 | 2022-08-18 | A method for producing sulfuric acid by vacuum concentration of waste sulfuric acid |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115448261B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108358176A (en) * | 2018-05-15 | 2018-08-03 | 杭州东日节能技术有限公司 | A kind of dilute sulfuric acid vacuum concentrating apparatus and method |
| CN110422827A (en) * | 2019-08-05 | 2019-11-08 | 贵州兰鑫石墨机电设备制造有限公司 | A kind of the Waste Sulfuric Acid recycling device and technique of dry chlorine gas |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3545519A (en) * | 1968-08-06 | 1970-12-08 | Maruzen Oil Co Ltd | Process and apparatus for the treatment of waste sulfuric acid |
| JP4328335B2 (en) * | 2006-03-31 | 2009-09-09 | 日鉱金属株式会社 | Operation method of contact sulfuric acid factory |
| JP2016180187A (en) * | 2016-07-05 | 2016-10-13 | パンパシフィック・カッパー株式会社 | Concentrating apparatus of sulfuric acid acidic solution, concentrating method of sulfuric acid acidic solution, and recovery method of crude nickel sulfate |
| CN206645816U (en) * | 2016-12-30 | 2017-11-17 | 上海奥格利环保工程有限公司 | A kind of sulfuric acid apparatus low temperature exhaust heat recovery system for setting up sour heat exchanger |
| CN108046222B (en) * | 2017-11-30 | 2021-07-09 | 湖北东方化工有限公司 | High-concentration sulfuric acid forced circulation heating system with quick scrubbing function and using method thereof |
| CN208532231U (en) * | 2018-07-04 | 2019-02-22 | 湖北东方化工有限公司 | A kind of fast cooling device of high-temperature concentrated sulfuric acid forced circulation system |
| CN112121452A (en) * | 2020-09-27 | 2020-12-25 | 江苏科技大学 | Desalination system and desalination method of ethylene glycol lean liquid containing high solubility salt in deep sea natural gas exploitation |
| CN213375167U (en) * | 2020-10-10 | 2021-06-08 | 南通星球石墨股份有限公司 | Electric heating kettle type evaporator for sulfuric acid concentration |
| CN114288700A (en) * | 2021-12-30 | 2022-04-08 | 安徽华尔泰化工股份有限公司 | Concentrated recovery system of waste sulfuric acid |
-
2022
- 2022-08-18 CN CN202210991606.0A patent/CN115448261B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108358176A (en) * | 2018-05-15 | 2018-08-03 | 杭州东日节能技术有限公司 | A kind of dilute sulfuric acid vacuum concentrating apparatus and method |
| CN110422827A (en) * | 2019-08-05 | 2019-11-08 | 贵州兰鑫石墨机电设备制造有限公司 | A kind of the Waste Sulfuric Acid recycling device and technique of dry chlorine gas |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115448261A (en) | 2022-12-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN115448261B (en) | A method for producing sulfuric acid by vacuum concentration of waste sulfuric acid | |
| CN209663273U (en) | A kind of cement water reducing agent reaction kettle | |
| CN204182620U (en) | Energy-saving full-automatic cleaning station | |
| CN100434570C (en) | Chromium stainless steel pickling apparatus and its cooling method | |
| CN108046222B (en) | High-concentration sulfuric acid forced circulation heating system with quick scrubbing function and using method thereof | |
| CN206404756U (en) | A kind of multi-function outer circulation kettle system | |
| CN110801784A (en) | Acrolein reaction system | |
| CN201704219U (en) | Concrete admixture production device | |
| CN211463086U (en) | Acrolein reaction system | |
| CN201074870Y (en) | Thermoregulation type device for supplying heat using sulfuric acid production low temperature waste heat | |
| CN212431916U (en) | Acid washing device of circulating gas heat exchanger | |
| CN104192864B (en) | The preparation facilities of ammonium bifluoride with high purity and preparation method | |
| CN221816087U (en) | A new reaction device for producing cross-linking agent TAIC | |
| CN211060217U (en) | Condensate water recovery device of heat exchange station | |
| CN220245632U (en) | Washing water system for phosphoric acid production | |
| CN207350991U (en) | A kind of totally-enclosed heat exchange cycle water system | |
| CN201209910Y (en) | Closed type heating device utilizing low temperature exhaust heat of sulfuric acid production | |
| CN220194828U (en) | Comprehensive temperature control additive production device | |
| CN219880758U (en) | Hot alkali liquor cleaning desilication silicon mud device | |
| CN110793340A (en) | Device and process for recovering waste heat of sewage in water seal tank of ore dressing shaft furnace | |
| CN219168412U (en) | Metronidazole reaction temperature control dropping device | |
| CN222799798U (en) | A chlorinated paraffin heat exchanger cleaning device | |
| CN221173053U (en) | Waste heat recovery device | |
| CN221832930U (en) | An online immersion circulation cleaning device for sulfonator | |
| CN204939365U (en) | A kind of energy-efficient reaction unit preparing polyether macromonomer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |