CN112678786B - System and method for preparing dilute nitric acid - Google Patents
System and method for preparing dilute nitric acid Download PDFInfo
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- CN112678786B CN112678786B CN202011547800.7A CN202011547800A CN112678786B CN 112678786 B CN112678786 B CN 112678786B CN 202011547800 A CN202011547800 A CN 202011547800A CN 112678786 B CN112678786 B CN 112678786B
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Abstract
The invention relates to a dilute nitric acid preparation system and a method, comprising the following steps: the gas circuit becomes line subassembly, lower flange and deflector etc.. The upper part in the reactor sets up gas circuit and becomes the line subassembly, the gas circuit becomes the line subassembly and is used for changing the gas circuit route trend in order to stop the gas-liquid mixture and march, the nitric oxide gas that generates in the reactor carries partial steam to constitute the upper portion of gas-liquid mixture and removes to the reactor, through gas circuit change line subassembly, gas-liquid mixture gas circuit route is changed to the horizontal direction by vertical direction, partial gas-liquid mixture begins the separation, gaseous part continues to move up, liquid part gathers the protruding part at the lower flange, and fall back to the reactor under self gravity effect along the protruding part of lower flange and continue to participate in the reaction, the setting through gas circuit change line subassembly makes gas-liquid separation effect good, need not to add the separator additionally and carries out gas-liquid separation, separation process is closed simultaneously, effectively prevent nitric oxide and air contact in the separation process and oxidized into nitrogen dioxide.
Description
Technical Field
The invention relates to the technical field of dilute nitric acid preparation, in particular to a dilute nitric acid preparation system and method.
Background
Nitric acid is strong acid with strong oxidizing property and corrosiveness, belongs to unitary inorganic strong acid, is one of six inorganic strong acids, and is also an important chemical raw material. Can be used for preparing chemical fertilizers, pesticides, explosives, dyes, salts and the like in industry; in organic chemistry, a mixed solution of concentrated nitric acid and concentrated sulfuric acid is an important nitrifying reagent, and the industrial application of nitric acid mainly comprises: as an essential raw material for nitrates and nitrates, nitric acid is used to produce a series of nitrate nitrogen fertilizers such as ammonium nitrate, potassium nitrate, etc.; also used for preparing nitrate or nitrate-containing explosive; is used for refining metal, namely firstly oxidizing impure metal into nitrate, removing impurities and then reducing; adding glycerol into concentrated nitric acid and concentrated sulfuric acid to obtain nitroglycerin. The nitric acid concentration requirements of the same industry are different.
Chinese patent publication No. CN104229761B discloses a dilute nitric acid preparation system and a preparation method thereof, and provides a dilute nitric acid preparation system which can directly prepare dilute nitric acid with concentration below 68% by utilizing fuming nitric acid and collect generated nitric oxide gas to meet social demands. The dilute nitric acid preparation device capable of circularly working is used for enabling the dilute nitric acid to circularly enter the reactor for reaction, so that on one hand, the reaction is more complete, on the other hand, the dilute nitric acid with different concentrations can be directly prepared by controlling the amount of injected soft water, the traditional route of generating concentrated nitric acid by fuming nitric acid and preparing the dilute nitric acid is changed, the method is convenient and quick, the turnover site and the turnover time in the traditional process are saved, the automatic collection of nitric oxide gas is realized, and the energy utilization rate is improved to a great extent.
However, in the above technical solution, the nitric oxide gas-liquid mixed gas is first separated by the condenser, and because the flow path of the nitric oxide gas-liquid mixed gas is single, the separation effect is poor, and an additional separator is required to be added for gas-liquid separation, and nitric oxide is very easy to be oxidized into nitrogen dioxide by contacting with air in the separation process, which finally results in the impurity of the collected nitric oxide gas, and affects the subsequent utilization of the collected nitric oxide.
Disclosure of Invention
Therefore, the invention provides a dilute nitric acid preparation system and method, which are used for solving the problems that in the prior art, the flow path of the nitric oxide gas-liquid mixed gas is single, the separation effect is poor, a separator is required to be additionally added for gas-liquid separation, nitric oxide is easily oxidized into nitrogen dioxide by contacting with air in the separation process, and finally the collected nitric oxide gas is impure, so that the subsequent utilization of the collected nitric oxide is affected.
The invention provides a dilute nitric acid preparation system, which comprises:
the device comprises a reactor, wherein a space is provided for dilute nitric acid preparation, an air passage line changing component is arranged at the upper part in the reactor and used for changing the trend of an air passage path so as to block the gas-liquid mixture from advancing, the air passage line changing component provides space for separating the gas-liquid mixture, the air passage line changing component comprises a lower convex plate, the lower convex plate is provided with a convex part along the vertical direction and towards the bottom of the reactor, two ends of the lower convex plate are fixedly connected to the inner side wall of the reactor, guide plates which are matched with the lower convex plate are symmetrically and fixedly connected to the lower side of the inner side wall of the reactor, and the lower convex plate and the guide plates form a guide cavity which is vertically and horizontally changed in the air passage path and communicated with a nitric oxide collecting tank through connecting pipes;
the circulating tank is communicated with the liquid outlet end of the reactor and is used for receiving dilute nitric acid discharged by the reactor;
the heat exchanger is communicated with the circulating tank and used for radiating the dilute nitric acid in the circulating process;
a dilute nitric acid discharge port located on a line between the recycle tank and the heat exchanger for discharging dilute nitric acid to a target concentration.
Preferably, the outside of connecting tube surrounds and is provided with the cooling jacket, connecting tube includes slope section and vertical section, the one end of slope section the direction cavity is linked together, the other end of slope section with the one end of vertical section is connected, the other end of vertical section with the nitric oxide collecting vessel is linked together.
Preferably, the pipe diameter area of the inclined section is larger than that of the vertical section, a plurality of partition plates penetrate through the connecting pipe fitting, the partition plates divide the connecting pipe fitting into a plurality of air path paths, and the partition plates are made of aluminum alloy.
Preferably, a connecting pipe is arranged between the vertical section and the nitric oxide collecting tank, the connecting pipe is fixedly connected with the vertical section, the connecting pipe is detachably connected with the nitric oxide collecting tank, a one-way inlet valve is arranged on the connecting pipe, and a one-way outlet valve is arranged at the outlet of the nitric oxide collecting tank.
Preferably, the nitric oxide collecting tank is internally provided with water, and the nitric oxide collecting tank receives nitric oxide in a drainage way.
Preferably, the lower convex plate is composed of flat plates which are symmetrically and obliquely arranged, the two flat plates are integrally connected towards one end of the bottom of the reactor to form a triangular bulge, the other ends of the two flat plates are fixedly connected with one end of a connecting plate, and the other end of the connecting plate is fixedly connected with the inner side wall of the reactor.
Preferably, the connecting plate is parallel to the guide plate, and the connecting plate is horizontally arranged.
Preferably, the auxiliary separation assembly is fixedly suspended on the inner top wall of the reactor, the auxiliary separation assembly comprises a fixing rod, one end of the fixing rod is fixedly connected with the inner top wall of the reactor, a spiral guide plate is fixedly connected to the fixing rod and used for assisting in separating a gas-liquid mixture, and the lower convex plate is uniformly provided with permeation holes.
Preferably, the inside of the fixed rod is of a cavity structure, and a semiconductor refrigerating sheet is arranged in the cavity of the fixed rod.
The invention provides a preparation method of dilute nitric acid, which comprises the following steps:
step 1: outputting fuming nitric acid into the reactor, spraying deionized water into the reactor from top to bottom in a spraying mode, reacting the fuming nitric acid in the reactor with the deionized water to generate nitrogen dioxide gas and dilute nitric acid, and reacting the nitrogen dioxide gas with the deionized water to generate nitric oxide gas and dilute nitric acid;
step 2: the nitric oxide gas generated in the reactor in the step 1 carries partial vapor to form a gas-liquid mixture, the gas-liquid mixture moves to the upper part of the reactor, the gas path of the gas-liquid mixture is changed from the vertical direction to the horizontal direction through the gas path line changing assembly, the gas-liquid mixture is blocked by the gas path line changing assembly, the gas-liquid mixture moves along a guide cavity formed by the lower convex plate and the guide plate, at the moment, partial gas-liquid mixture starts to separate, the gas part continuously moves upwards, the liquid part is gathered on the convex part of the lower convex plate and falls back into the reactor along the convex part of the lower convex plate under the action of self gravity to continuously participate in the reaction;
step 3: in the step 2, the gas part enters the nitric oxide collecting tank along the connecting pipe fitting to be collected, water is filled in the nitric oxide collecting tank, the nitric oxide collecting tank receives nitric oxide in a drainage method, and in the moving process of the connecting pipe fitting, the gas-liquid mixture continuously separates liquid from gas and falls down;
step 4: the dilute nitric acid obtained by the reaction in the step 1 flows into the circulating tank from the bottom of the reactor, the dilute nitric acid in the circulating tank enters the heat exchanger through the circulating pump, the heat exchanger dissipates heat of the dilute nitric acid in the circulating process, and the dissipated dilute nitric acid flows back to the middle upper part in the reactor through the reflux port to participate in the reaction again, so that the reaction is promoted to be complete;
step 5: and (3) according to the required nitric acid concentration, in the reaction of the step (4), reducing or stopping spraying deionized water, enabling the dilute nitric acid in the circulating tank to enter the heat exchanger through the circulating pump for heat exchange, then entering the reactor, enabling water in the dilute nitric acid to further react with nitrogen dioxide in the step to generate dilute nitric acid, and enabling the dilute nitric acid to flow into the circulating tank, so that the concentration of the dilute nitric acid in the circulating tank is gradually increased until the required concentration of the dilute nitric acid is obtained, and discharging the dilute nitric acid through the dilute nitric acid discharge port.
Compared with the prior art, the invention has the beneficial effects that the upper part in the reactor is provided with the gas path line changing component which is used for changing the trend of the gas path to block the gas-liquid mixture from advancing, the gas path line changing component provides space for separating the gas-liquid mixture, the gas path line changing component comprises the lower convex plate, the lower convex plate is provided with the convex part towards the bottom of the reactor along the vertical direction, the two ends of the lower convex plate are fixedly connected on the inner side wall of the reactor, the inner side wall of the reactor is symmetrically and fixedly connected with the guide plate which is matched with the lower convex plate and is positioned on the lower side of the lower convex plate, the lower convex plate and the guide plate form the guide cavity of the vertical direction-changing horizontal gas path, the nitric oxide gas generated in the reactor carries partial vapor to form the gas-liquid mixture to move towards the upper part of the reactor, the gas-liquid mixture is changed from the vertical direction to the horizontal direction through the gas path line changing component, the gas-liquid mixture moves along a guide cavity formed by the lower convex plate and the guide plate, at the moment, part of the gas-liquid mixture starts to separate, the gas part continuously moves upwards, the liquid part gathers on the convex part of the lower convex plate and falls back into the reactor along the convex part of the lower convex plate under the action of self gravity to continuously participate in reaction, the guide cavity is communicated with the nitric oxide collecting tank through a connecting pipe fitting, the gas part enters the nitric oxide collecting tank along the connecting pipe fitting to be collected, water is filled in the nitric oxide collecting tank, the nitric oxide collecting tank receives nitric oxide in a drainage way, in the moving process of the connecting pipe fitting, liquid and gas are continuously separated and fall down, the trend of a gas path is changed through the arrangement of the gas-path wire changing assembly to block the gas-liquid mixture from moving, the space is provided for the separation of the gas-liquid mixture, the gas-liquid separation effect is good, a separator is not required to be additionally added for gas-liquid separation, and the separation process is closed, so that nitric oxide is effectively prevented from being oxidized into nitrogen dioxide when being contacted with air in the separation process;
further, the outside of connecting pipe fitting surrounds and is provided with the cooling jacket, connecting pipe fitting includes slope section and vertical section, the one end direction cavity of slope section is linked together, the other end of slope section is connected with the one end of vertical section, the other end of vertical section is linked together with the nitric oxide collecting vessel, gas-liquid mixture is at connecting pipe fitting removal in-process, receive the cooling effect of cooling jacket, gas-liquid further separates, constantly have liquid and gas separation and whereabouts, the messenger of slope section and vertical section connects the pipe fitting and has the route inflection point, can further increase gas-liquid separation effect.
Further, the pipe diameter area of the inclined section is larger than that of the vertical section, the plurality of partition plates penetrate through the connecting pipe fitting, the plurality of partition plates divide the inner part of the connecting pipe fitting into a plurality of air path paths, the partition plates are made of aluminum alloy, the aluminum alloy is fast in heat conduction, the partition plates are especially formed to further increase the air-liquid separation effect, and the partition plates divide the inner part of the connecting pipe fitting into a plurality of air path paths, so that the air-liquid mixture can separately advance, and the working noise of the system can be reduced to a certain extent.
Further, be provided with the connecting pipe between vertical section and the nitric oxide collecting tank, fixed connection between connecting pipe and the vertical section, can dismantle between connecting pipe and the nitric oxide collecting tank and be connected, install one-way inlet valve on the connecting pipe, the one-way outlet valve is installed to the exit of nitric oxide collecting tank, the connecting pipe sets up for making things convenient for being connected between vertical section and the nitric oxide collecting tank, nitric oxide gas gets into in the nitric oxide collecting tank along the one-way inlet valve, the inside of nitric oxide collecting tank is equipped with water, the nitric oxide collecting tank receives the nitric oxide with the drainage method, the water is discharged along the one-way outlet valve simultaneously, this kind of nitric oxide collecting mode can avoid nitric oxide and air contact, by oxidation, thereby guarantee the purity of nitric oxide.
Further, the lower convex plate is composed of flat plates which are symmetrically and obliquely arranged, the two flat plates are integrally formed and connected towards one end of the bottom of the reactor to form a triangular bulge, the other ends of the two flat plates are fixedly connected with one end of a connecting plate, the other ends of the connecting plate are fixedly connected with the inner side wall of the reactor, a gas-liquid mixture advances along a guiding cavity formed by the lower convex plate and the guiding plate, at the moment, part of the gas-liquid mixture starts to separate, the gas part continuously moves upwards, the liquid part gathers at the triangular bulge, and the bulge along the lower convex plate falls back into the reactor under the action of self gravity to continuously participate in the reaction.
Further, the connecting plate is parallel to the guide plate, the connecting plate is horizontally arranged, the connecting plate and the guide plate form a horizontal cavity part of the guide cavity, the gas-liquid mixture advancing route is changed, and a space is provided for gas-liquid mixture separation.
Further, the auxiliary separation assembly is fixedly suspended on the inner top wall of the reactor, the auxiliary separation assembly comprises a fixing rod, one end of the fixing rod is fixedly connected with the inner top wall of the reactor, a spiral guide plate is fixedly connected to the fixing rod and used for assisting in separating a gas-liquid mixture, a transmission hole is uniformly formed in the lower convex plate, the auxiliary separation assembly is used for further assisting in separating the gas-liquid mixture, part of the gas-liquid mixture enters into the part of the auxiliary separation assembly through the lower convex plate, the auxiliary separation assembly continuously moves upwards along the spiral guide plate, and liquid and gas are separated and fall under the action of gravity in the moving process.
Further, the inside of dead lever is the cavity structure, installs the semiconductor refrigeration piece in the cavity of dead lever, through the work of semiconductor refrigeration piece for the dead lever becomes the cold source, and in the continuous upward advancing process of gas-liquid mixture along spiral stock guide, constantly with the cold source contact, further increase gas-liquid separation effect.
Drawings
FIG. 1 is a schematic diagram of a dilute nitric acid preparation system according to the present invention;
FIG. 2 is a schematic diagram of the gas circuit variable line assembly of the present invention;
FIG. 3 is a side view of the connection tubing and nitric oxide collection canister of the present invention;
fig. 4 is a schematic view of the structure of the lower convex plate of the present invention.
In the figure: 1-reactor, 2-gas circuit change line subassembly, 201-lower flange, 202-deflector, 203-direction cavity, 3-connecting tube spare, 301-inclined section, 302-vertical section, 4-nitric oxide collection jar, 5-circulation jar, 6-heat exchanger, 7-rare nitric acid discharge port, 8-division board, 9-connecting pipe, 10-connecting plate, 11-auxiliary separation subassembly, 111-dead lever, 112-spiral stock guide.
Detailed Description
Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are merely for explaining the technical principles of the present invention, and are not intended to limit the scope of the present invention.
Referring to fig. 1, which is a schematic structural diagram of a dilute nitric acid preparation system according to the present invention, the dilute nitric acid preparation system includes:
the reactor 1, it provides space for dilute nitric acid preparation, the upper portion is provided with the gas circuit lane change subassembly 2 in the reactor 1, the gas circuit lane change subassembly 2 is used for changing the gas circuit route trend in order to stop gas-liquid mixture and march, it provides space for gas-liquid mixture separation, please refer to the FIG. 2 and show, the gas circuit lane change subassembly 2 includes down the flange 201, down the flange 201 along vertical direction and towards the reactor 1 bottom is provided with protruding portion, the both ends of flange 201 down fixedly connected with on the inside wall of reactor 1, on the inside wall of reactor 1 and be located the downside symmetry fixedly connected with of flange 201 with the deflector 202 that the flange 201 used down cooperatees, the flange 201 down with deflector 202 constitutes by vertical diversion horizontal gas circuit route's direction guide cavity 203, the vapor carried by the nitric oxide gas generated in the reactor 1 forms a vapor-liquid mixture, the vapor-liquid mixture moves to the upper part of the reactor 1, the vapor-liquid mixture gas path is changed from the vertical direction to the horizontal direction through the gas path changing line assembly 2, the vapor-liquid mixture is blocked by the gas path changing line assembly 2, the vapor-liquid mixture moves along the guiding cavity 203 formed by the lower convex plate 201 and the guiding plate 202, at the moment, part of the vapor-liquid mixture starts to separate, the gas part continuously moves upwards, the liquid part gathers at the convex part of the lower convex plate 201 and falls back into the reactor 1 under the action of self gravity along the convex part of the lower convex plate 201 to continuously participate in the reaction, the guiding cavity 203 is communicated with the nitric oxide collecting tank 4 through the connecting pipe fitting 3, the gas part enters into the nitric oxide collecting tank 4 along the connecting pipe fitting 3 to be collected, the nitric oxide collecting tank 4 is internally filled with water, the nitric oxide collecting tank 4 receives nitric oxide in a drainage method, in the moving process of the connecting pipe fitting 3, liquid and gas are separated and fall continuously, the arrangement of the gas path line changing assembly 2 changes the trend of a gas path to block the gas-liquid mixture from advancing, a space is provided for separating the gas-liquid mixture, the gas-liquid separation effect is good, a separator is not required to be additionally added for gas-liquid separation, the separation process is closed, and nitric oxide is effectively prevented from being oxidized into nitrogen dioxide when being contacted with air in the separation process;
a circulation tank 5 which is communicated with the liquid outlet end of the reactor 1 and is used for receiving the dilute nitric acid discharged from the reactor 1;
the heat exchanger 6 is communicated with the circulating tank 5 and is used for radiating the dilute nitric acid in the circulating process, the dilute nitric acid obtained by the reaction in the reactor 1 flows into the circulating tank 5 from the bottom of the reactor 1, the dilute nitric acid in the circulating tank 5 enters the heat exchanger 6 through a circulating pump, the heat exchanger 6 radiates the dilute nitric acid in the circulating process, and the radiated dilute nitric acid flows back to the middle upper part in the reactor 1 through a backflow port to participate in the reaction again, so that the reaction is promoted to be complete;
a dilute nitric acid outlet 7, which is located on the pipeline between the circulation tank 5 and the heat exchanger 6, and is used for discharging dilute nitric acid reaching the target concentration, and spraying deionized water is reduced or stopped according to the required nitric acid concentration, the dilute nitric acid in the circulation tank 5 enters the heat exchanger 6 through a circulation pump to exchange heat, then enters the reactor 1, water in the dilute nitric acid further reacts with nitrogen dioxide in the step 1 to generate dilute nitric acid, and flows into the circulation tank 5, so that the concentration of the dilute nitric acid in the circulation tank 5 is gradually increased until the required concentration of the dilute nitric acid is obtained, and the dilute nitric acid is discharged at the dilute nitric acid outlet 7.
Referring to fig. 1, specifically, the connecting tube 3 is provided with a cooling jacket around the outside of the connecting tube 3, the connecting tube 3 includes an inclined section 301 and a vertical section 302, one end of the inclined section 301 is connected to the guiding cavity 203, the other end of the inclined section 301 is connected to one end of the vertical section 302, the other end of the vertical section 302 is connected to the nitric oxide collecting tank 4, the gas-liquid mixture is cooled by the cooling jacket during the moving process of the connecting tube 3, the gas and the liquid are further separated, the liquid and the gas are continuously separated and fall, and the inclined section 301 and the vertical section 302 enable the connecting tube 3 to have a path inflection point, so that the gas-liquid separation effect can be further increased.
Referring to fig. 3, specifically, the pipe diameter area of the inclined section 301 is larger than that of the vertical section 302, and a plurality of partition boards 8 penetrate through the inside of the connecting pipe 3, the partition boards 8 divide the inside of the connecting pipe 3 into a plurality of gas paths, the partition boards 8 are made of aluminum alloy, the aluminum alloy has faster heat conduction, and especially the partition boards 8 further increase the gas-liquid separation effect, and the partition boards 8 divide the inside of the connecting pipe 3 into a plurality of gas paths, so that the gas-liquid mixture separately advances, and the system working noise can be reduced to a certain extent.
Referring to fig. 3, specifically, a connecting pipe 9 is disposed between the vertical section 302 and the nitric oxide collecting tank 4, the connecting pipe 9 is fixedly connected with the vertical section 302, the connecting pipe 9 is detachably connected with the nitric oxide collecting tank 4, a one-way inlet valve is installed on the connecting pipe 9, a one-way outlet valve is installed at the outlet of the nitric oxide collecting tank 4, the connecting pipe 9 is provided for facilitating the connection between the vertical section 302 and the nitric oxide collecting tank 4, nitric oxide gas enters the nitric oxide collecting tank 4 along the one-way inlet valve, water is filled in the nitric oxide collecting tank 4, the nitric oxide collecting tank 4 receives nitric oxide in a drainage manner, and meanwhile, the water is discharged along the one-way outlet valve.
Referring to fig. 4, specifically, the lower convex plate 201 is formed by symmetrically and obliquely arranged flat plates, one ends of the two flat plates facing the bottom of the reactor 1 are integrally formed and connected to form a triangular protrusion, the other ends of the two flat plates are fixedly connected to one end of the connecting plate 10, the other end of the connecting plate 10 is fixedly connected to the inner side wall of the reactor 1, the gas-liquid mixture advances along the guiding cavity 203 formed by the lower convex plate 201 and the guiding plate 202, at this time, part of the gas-liquid mixture begins to separate, the gas part continues to move upwards, the liquid part gathers in the triangular protrusion, and the liquid part falls back into the reactor 1 along the protrusion of the lower convex plate 201 under the action of self gravity to continue to participate in the reaction.
Referring to fig. 4, specifically, the connection plate 10 is parallel to the guide plate 202, the connection plate 10 is horizontally disposed, the connection plate 10 and the guide plate 202 form a horizontal cavity portion of the guide cavity 203, and a gas-liquid mixture travelling path is changed to provide a space for separating the gas-liquid mixture.
Referring to fig. 1, specifically, an auxiliary separation assembly 11 is fixedly suspended on the inner top wall of the reactor 1, the auxiliary separation assembly 11 includes a fixing rod 111, one end of the fixing rod 111 is fixedly connected with the inner top wall of the reactor 1, a spiral material guiding plate 112 is fixedly connected to the fixing rod 111, the spiral material guiding plate 112 is used for assisting in separating a gas-liquid mixture, a transmission hole is uniformly formed in the lower convex plate 201, the auxiliary separation assembly 11 further assists in separating the gas-liquid mixture, part of the gas-liquid mixture enters the auxiliary separation assembly 11 through the lower convex plate 201, and continuously travels upwards along the spiral material guiding plate 112, and liquid and gas separated continuously falls under the action of gravity in the travelling process.
Referring to fig. 1, specifically, the inside of the fixing rod 111 has a cavity structure, a semiconductor refrigeration sheet is installed in the cavity of the fixing rod 111, and the semiconductor refrigeration sheet works to make the fixing rod 111 become a cold source, and in the process that the gas-liquid mixture continuously travels upwards along the spiral guide plate 112, the gas-liquid mixture is in contact with the cold source at any time, so as to further increase the gas-liquid separation effect.
Referring to fig. 1, a method for preparing dilute nitric acid comprises the following steps:
step 1: outputting fuming nitric acid into the reactor 1, spraying deionized water into the reactor 1 from top to bottom in a spraying manner, and reacting the fuming nitric acid in the reactor 1 with the deionized water to generate nitrogen dioxide gas and dilute nitric acid, wherein the nitrogen dioxide gas reacts with the deionized water to generate nitric oxide gas and dilute nitric acid;
step 2: in the step 1, the nitric oxide gas generated in the reactor 1 carries part of water vapor to form a gas-liquid mixture, the gas-liquid mixture moves to the upper part of the reactor 1, the gas path of the gas-liquid mixture is changed from the vertical direction to the horizontal direction through the gas path changing line assembly 2, the gas-liquid mixture is blocked by the gas path changing line assembly 2, the gas-liquid mixture moves along the guiding cavity 203 formed by the lower convex plate 201 and the guiding plate 202, at the moment, part of the gas-liquid mixture starts to separate, the gas part moves upwards continuously, the liquid part gathers on the convex part of the lower convex plate 201 and falls back into the reactor 1 along the convex part of the lower convex plate 201 under the action of self gravity to continuously participate in the reaction;
step 3: in the step 2, the gas part enters the nitric oxide collecting tank 4 along the connecting pipe fitting 3 to be collected, water is filled in the nitric oxide collecting tank 4, the nitric oxide collecting tank 4 receives nitric oxide in a drainage method, and in the moving process of the connecting pipe fitting 3, the gas-liquid mixture continuously separates liquid from gas and falls down;
step 4: the dilute nitric acid obtained by the reaction in the step 1 flows into the circulating tank 5 from the bottom of the reactor 1, the dilute nitric acid in the circulating tank 5 enters the heat exchanger 6 through a circulating pump, the heat exchanger 6 dissipates heat of the dilute nitric acid in the circulating process, and the dissipated dilute nitric acid flows back to the middle upper part in the reactor 1 through a backflow port to participate in the reaction again, so that the reaction is promoted to be complete;
step 5: according to the required nitric acid concentration, in the reaction of the step 4, spraying deionized water is reduced or stopped, the dilute nitric acid in the circulating tank 5 enters the heat exchanger 6 through a circulating pump to exchange heat, then enters the reactor 1, water in the dilute nitric acid further reacts with nitrogen dioxide in the step 1 to generate dilute nitric acid, and the dilute nitric acid flows into the circulating tank 5, so that the concentration of the dilute nitric acid in the circulating tank 5 is gradually increased until the required concentration of the dilute nitric acid is obtained, and the dilute nitric acid is discharged from the dilute nitric acid discharge port 7.
Thus far, the technical solution of the present invention has been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of protection of the present invention is not limited to these specific embodiments. Equivalent modifications and substitutions for related technical features may be made by those skilled in the art without departing from the principles of the present invention, and such modifications and substitutions will be within the scope of the present invention.
The foregoing description is only of the preferred embodiments of the invention and is not intended to limit the invention; various modifications and variations of the present invention will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (8)
1. A dilute nitric acid production system comprising: the device comprises a reactor (1), wherein a space is provided for dilute nitric acid preparation, an air passage wire changing component (2) is arranged at the upper part in the reactor (1), the air passage wire changing component (2) is used for changing the trend of an air passage path so as to block an air-liquid mixture from advancing, the space is provided for separating the air-liquid mixture, the air passage wire changing component (2) comprises a lower convex plate (201), the lower convex plate (201) is provided with a convex part along the vertical direction and towards the bottom of the reactor (1), two ends of the lower convex plate (201) are fixedly connected to the inner side wall of the reactor (1), guide plates (202) which are matched with the lower convex plate (201) are symmetrically and fixedly connected to the lower side of the reactor (1), the lower convex plate (201) and the guide plates (202) form a guide cavity (203) of a vertical direction-changing horizontal air passage path, and the guide cavity (203) is communicated with a nitric oxide collecting tank (4) through a connecting pipe fitting (3);
a circulation tank (5) which is communicated with the liquid outlet end of the reactor (1) and is used for receiving the dilute nitric acid discharged from the reactor (1);
a heat exchanger (6) which is communicated with the circulating tank (5) and used for radiating the dilute nitric acid in the circulating process;
a dilute nitric acid discharge port (7) located on a line between the circulation tank (5) and the heat exchanger (6) for discharging dilute nitric acid reaching a target concentration;
the outside of the connecting pipe fitting (3) is surrounded by a cooling jacket, the connecting pipe fitting (3) comprises an inclined section (301) and a vertical section (302), one end of the inclined section (301) is communicated with the guide cavity (203), the other end of the inclined section (301) is connected with one end of the vertical section (302), and the other end of the vertical section (302) is communicated with the nitric oxide collecting tank (4);
the inside of the nitric oxide collecting tank (4) is provided with water, and the nitric oxide collecting tank (4) receives nitric oxide in a drainage mode.
2. The dilute nitric acid preparation system according to claim 1, wherein the pipe diameter area of the inclined section (301) is larger than the pipe diameter area of the vertical section (302), a plurality of partition plates (8) are arranged inside the connecting pipe fitting (3) in a penetrating manner, the partition plates (8) divide the inside of the connecting pipe fitting (3) into a plurality of air path paths, and the partition plates (8) are made of aluminum alloy.
3. The dilute nitric acid preparation system according to claim 2, wherein a connecting pipe (9) is arranged between the vertical section (302) and the nitric oxide collecting tank (4), the connecting pipe (9) is fixedly connected with the vertical section (302), the connecting pipe (9) is detachably connected with the nitric oxide collecting tank (4), a one-way inlet valve is arranged on the connecting pipe (9), and a one-way outlet valve is arranged at the outlet of the nitric oxide collecting tank (4).
4. The dilute nitric acid preparation system according to claim 1, wherein the lower convex plate (201) is composed of flat plates which are symmetrically and obliquely arranged, one ends of the two flat plates, which face the bottom of the reactor (1), are integrally connected to form a triangular bulge, the other ends of the two flat plates are fixedly connected with one end of a connecting plate (10), and the other end of the connecting plate (10) is fixedly connected with the inner side wall of the reactor (1).
5. A dilute nitric acid production system according to claim 4, wherein said connection plate (10) is parallel to said guiding plate (202), said connection plate (10) being arranged horizontally.
6. The dilute nitric acid preparation system according to any of claims 1 to 5, wherein an auxiliary separation assembly (11) is fixedly suspended on the inner top wall of the reactor (1), the auxiliary separation assembly (11) comprises a fixing rod (111), one end of the fixing rod (111) is fixedly connected with the inner top wall of the reactor (1), a spiral material guide plate (112) is fixedly connected on the fixing rod (111), the spiral material guide plate (112) is used for assisting in separating a gas-liquid mixture, and the lower convex plate (201) is uniformly provided with permeation holes.
7. The dilute nitric acid preparation system according to claim 6, wherein the inside of the fixing rod (111) is of a cavity structure, and a semiconductor refrigerating sheet is arranged in the cavity of the fixing rod (111).
8. The preparation method of the dilute nitric acid is characterized by comprising the following steps of:
step 1: outputting fuming nitric acid into the reactor (1), spraying deionized water into the fuming nitric acid in a spraying manner from top to bottom in the reactor (1), and reacting the fuming nitric acid in the reactor (1) with the deionized water to generate nitrogen dioxide gas and dilute nitric acid, wherein the nitrogen dioxide gas reacts with the deionized water to generate nitric oxide gas and dilute nitric acid;
step 2: in the step 1, nitric oxide gas generated in the reactor (1) carries partial vapor to form a gas-liquid mixture, the gas-liquid mixture moves towards the upper part of the reactor (1), the gas path of the gas-liquid mixture is changed from the vertical direction to the horizontal direction through the gas path line changing assembly (2), the gas-liquid mixture is blocked by the gas path line changing assembly (2) to travel, the gas-liquid mixture travels along a guide cavity (203) formed by the lower convex plate (201) and the guide plate (202), at the moment, partial gas-liquid mixture starts to separate, the gas part continuously moves upwards, and the liquid part gathers on the convex part of the lower convex plate (201) and falls back into the reactor (1) along the convex part of the lower convex plate (201) under the action of self gravity to continuously participate in the reaction;
step 3: in the step 2, the gas part enters the nitric oxide collecting tank (4) along the connecting pipe fitting (3) to be collected, water is filled in the nitric oxide collecting tank (4), the nitric oxide collecting tank (4) receives nitric oxide in a drainage method, and the gas-liquid mixture continuously separates liquid from gas and falls in the moving process of the connecting pipe fitting (3);
step 4: the dilute nitric acid obtained by the reaction in the step 1 flows into the circulating tank (5) from the bottom of the reactor (1), the dilute nitric acid in the circulating tank (5) enters the heat exchanger (6) through a circulating pump, the heat exchanger (6) dissipates heat of the dilute nitric acid in the circulating process, and the dissipated dilute nitric acid flows back to the middle upper part in the reactor (1) through a backflow port to participate in the reaction again, so that the reaction is promoted to be complete;
step 5: according to the required nitric acid concentration, in the reaction of the step 4, spraying deionized water is reduced or stopped, the dilute nitric acid in the circulating tank (5) enters the heat exchanger (6) through a circulating pump to exchange heat, then enters the reactor (1), water in the dilute nitric acid further reacts with nitrogen dioxide in the step 1 to generate dilute nitric acid, and the dilute nitric acid flows into the circulating tank (5), so that the concentration of the dilute nitric acid in the circulating tank (5) is gradually increased until the required concentration of the dilute nitric acid is obtained, and the dilute nitric acid is discharged from the dilute nitric acid discharge port (7).
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5670127A (en) * | 1995-09-26 | 1997-09-23 | The Boc Group, Inc. | Process for the manufacture of nitric oxide |
| CN102838096A (en) * | 2012-09-24 | 2012-12-26 | 杭州先进富春化工有限公司 | Joint production method and production device of dilute nitric acid and concentrated nitric acid |
| JP2014189471A (en) * | 2013-03-28 | 2014-10-06 | Sumitomo Seika Chem Co Ltd | Apparatus for recovering nitrogen monoxide gas |
| CN104229761A (en) * | 2014-08-22 | 2014-12-24 | 安徽淮化股份有限公司 | Preparation system and preparation method of dilute nitric acid |
| CN204151072U (en) * | 2014-08-22 | 2015-02-11 | 安徽淮化股份有限公司 | A kind of dust technology preparation system |
| CN212127531U (en) * | 2019-09-11 | 2020-12-11 | 南京延长反应技术研究院有限公司 | Nitric acid industry preparation system based on micro-interface is reinforceed |
-
2020
- 2020-12-24 CN CN202011547800.7A patent/CN112678786B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5670127A (en) * | 1995-09-26 | 1997-09-23 | The Boc Group, Inc. | Process for the manufacture of nitric oxide |
| CN102838096A (en) * | 2012-09-24 | 2012-12-26 | 杭州先进富春化工有限公司 | Joint production method and production device of dilute nitric acid and concentrated nitric acid |
| JP2014189471A (en) * | 2013-03-28 | 2014-10-06 | Sumitomo Seika Chem Co Ltd | Apparatus for recovering nitrogen monoxide gas |
| CN104229761A (en) * | 2014-08-22 | 2014-12-24 | 安徽淮化股份有限公司 | Preparation system and preparation method of dilute nitric acid |
| CN204151072U (en) * | 2014-08-22 | 2015-02-11 | 安徽淮化股份有限公司 | A kind of dust technology preparation system |
| CN212127531U (en) * | 2019-09-11 | 2020-12-11 | 南京延长反应技术研究院有限公司 | Nitric acid industry preparation system based on micro-interface is reinforceed |
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