CN115389708A - Test device for accelerating determination of ammonia nitrogen substance residue in concrete - Google Patents
Test device for accelerating determination of ammonia nitrogen substance residue in concrete Download PDFInfo
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- CN115389708A CN115389708A CN202210936247.9A CN202210936247A CN115389708A CN 115389708 A CN115389708 A CN 115389708A CN 202210936247 A CN202210936247 A CN 202210936247A CN 115389708 A CN115389708 A CN 115389708A
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- 238000012360 testing method Methods 0.000 title claims abstract description 37
- 239000000126 substance Substances 0.000 title claims abstract description 36
- XKMRRTOUMJRJIA-UHFFFAOYSA-N ammonia nh3 Chemical compound N.N XKMRRTOUMJRJIA-UHFFFAOYSA-N 0.000 title claims abstract description 35
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 162
- 238000003756 stirring Methods 0.000 claims abstract description 100
- 229910021529 ammonia Inorganic materials 0.000 claims abstract description 38
- 239000000463 material Substances 0.000 claims abstract description 33
- 238000000034 method Methods 0.000 claims abstract description 33
- 230000008569 process Effects 0.000 claims abstract description 22
- 238000012544 monitoring process Methods 0.000 claims abstract description 8
- 238000010521 absorption reaction Methods 0.000 claims description 73
- 238000002474 experimental method Methods 0.000 claims description 49
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 48
- 238000010438 heat treatment Methods 0.000 claims description 38
- 230000005540 biological transmission Effects 0.000 claims description 28
- 239000007789 gas Substances 0.000 claims description 24
- 239000007788 liquid Substances 0.000 claims description 22
- 238000010907 mechanical stirring Methods 0.000 claims description 22
- 238000004448 titration Methods 0.000 claims description 20
- 238000002156 mixing Methods 0.000 claims description 19
- 239000010881 fly ash Substances 0.000 claims description 18
- 238000001132 ultrasonic dispersion Methods 0.000 claims description 14
- 230000007246 mechanism Effects 0.000 claims description 10
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 claims description 9
- 239000004327 boric acid Substances 0.000 claims description 9
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 claims description 9
- 238000010998 test method Methods 0.000 claims description 9
- 230000001133 acceleration Effects 0.000 claims description 8
- 239000003153 chemical reaction reagent Substances 0.000 claims description 8
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N EtOH Substances CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 6
- 230000009471 action Effects 0.000 claims description 6
- 230000008859 change Effects 0.000 claims description 6
- 229960000907 methylthioninium chloride Drugs 0.000 claims description 6
- 238000007789 sealing Methods 0.000 claims description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 6
- 238000004804 winding Methods 0.000 claims description 6
- CVTZKFWZDBJAHE-UHFFFAOYSA-N [N].N Chemical group [N].N CVTZKFWZDBJAHE-UHFFFAOYSA-N 0.000 claims description 5
- 238000004364 calculation method Methods 0.000 claims description 4
- 238000011049 filling Methods 0.000 claims description 4
- 239000002994 raw material Substances 0.000 claims description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 3
- 239000002253 acid Substances 0.000 claims description 3
- 239000004568 cement Substances 0.000 claims description 3
- 238000007865 diluting Methods 0.000 claims description 3
- 239000012153 distilled water Substances 0.000 claims description 3
- 238000011068 loading method Methods 0.000 claims description 3
- 239000002184 metal Substances 0.000 claims description 3
- 125000000325 methylidene group Chemical group [H]C([H])=* 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 3
- 238000004321 preservation Methods 0.000 claims description 3
- 239000000741 silica gel Substances 0.000 claims description 3
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- 238000007664 blowing Methods 0.000 claims description 2
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- 238000001514 detection method Methods 0.000 abstract description 8
- 238000013461 design Methods 0.000 abstract description 4
- 239000002956 ash Substances 0.000 description 3
- 239000002585 base Substances 0.000 description 3
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- 238000009826 distribution Methods 0.000 description 2
- 239000000499 gel Substances 0.000 description 2
- 238000004806 packaging method and process Methods 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 239000006096 absorbing agent Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
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- 238000013401 experimental design Methods 0.000 description 1
- 239000003546 flue gas Substances 0.000 description 1
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- 238000002955 isolation Methods 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/0004—Gaseous mixtures, e.g. polluted air
- G01N33/0009—General constructional details of gas analysers, e.g. portable test equipment
- G01N33/0027—General constructional details of gas analysers, e.g. portable test equipment concerning the detector
- G01N33/0036—General constructional details of gas analysers, e.g. portable test equipment concerning the detector specially adapted to detect a particular component
- G01N33/0054—Ammonia
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/38—Concrete; Lime; Mortar; Gypsum; Bricks; Ceramics; Glass
- G01N33/383—Concrete or cement
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
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- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
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- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
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Abstract
The invention relates to the technical field of ammonia gas release detection in concrete, in particular to a test device and a method for accelerating determination of ammonia nitrogen substance residue in concrete. Through reasonable device structural design, solve the ammonia detector and can not accurately survey out the ammonia concentration problem in the proof box under the air feed condition, realize simultaneously throwing the material, stirring to the ammonia release amount monitoring of the hardening overall process that condenses to the concrete, improve detection method's accuracy and adaptability, shorten the survey cycle, improve detection efficiency.
Description
Technical Field
The invention relates to the technical field of ammonia gas release detection in concrete, in particular to a test device and a method for accelerating determination of ammonia nitrogen substance residue in concrete.
Background
The fly ash is an important admixture for premixed concrete production, the quality and the material property of the fly ash are changed along with the improvement of flue gas denitration of a coal-fired power plant, the fly ash which is used in a large amount in the prior engineering is the denitration fly ash, ammonia gas can be released to different degrees in the processes of storage, transportation, concrete mixing and pouring maintenance, and the harm to human health and the surrounding environment is caused.
Therefore, the method for measuring the ammonia nitrogen substance residue and ammonia gas release amount in the concrete is provided, and has important significance for determining the ammonia gas release rule in the concrete and guiding the denitration fly ash to be applied to the production and construction of the concrete.
The invention of the patent number CN109827917A, CN209878585U and the utility model patent disclose a device and a method for continuously measuring ammonia release amount in concrete, which simulate the concrete vibrating and hardening process by regulating and controlling the environmental conditions of temperature and wind speed in an experiment box, and realize the real-time detection of ammonia release amount in the whole process of concrete pouring and curing. However, the above technical solutions do not consider the release of a large amount of ammonia gas during the processes of concrete feeding, mixing and stirring, and the gas concentration in the experimental box is dynamically changed during the process of continuously supplying air to the box by the blower, so that the data recorded by the ammonia gas monitor may deviate from the actual data; the provided measuring method has the disadvantages of complex operation process and long detection period, and particularly, the step of detecting the ammonia concentration in the absorption liquid by a spectrophotometry method is very complicated, and the practical application and popularization are insufficient.
In summary, the invention provides a rapid testing device and a rapid testing method for ammonia nitrogen substance residues, so as to solve the problems.
Disclosure of Invention
The invention aims to provide a test device and a method for measuring ammonia nitrogen substance residue in concrete, and through reasonable device structure design, the problem that an ammonia gas detector cannot accurately measure the ammonia gas concentration in a test box under the condition of air supply is solved, and meanwhile, the ammonia gas release amount monitoring in the whole process from concrete feeding, stirring to coagulation hardening is realized, so that the accuracy and the adaptability of the detection method are improved, the measurement period is shortened, and the detection efficiency is improved.
The technical purpose of the invention is realized by the following technical scheme:
a test device for accelerating determination of ammonia nitrogen substance residue in concrete comprises an experiment box 1, an ammonia gas monitoring and absorbing system and an air supply system, wherein the experiment box 1 comprises a material stirring mechanism, a lifting mechanism and a heating structure;
the ammonia monitoring and absorption system comprises:
the ammonia gas detectors are fixed on the experiment box 1 and used for detecting the concentration of ammonia gas in the experiment box 1, and the number of the ammonia gas detectors is multiple;
the barometer 3 is fixed on the experimental box 1;
the ammonia absorption bottle 4 is connected with the exhaust hole 25 above the heat preservation box 1 through a gas path pipeline, and the gas path pipeline is provided with a gas valve 37 and a flow stopper 38;
the air supply system comprises an air diffuser 5, a flow controller 6, a ventilating pipe 39 and an air supply fan 7, wherein the air diffuser 5 is fixed at the bottom of the experiment box and is connected with the flow controller 6 and the air supply fan 7 outside the experiment box 1 through the ventilating pipe 39.
Further, the material stirring mechanism consists of a mechanical stirring unit, an ultrasonic dispersion unit 8, a mechanical vibration unit 9 and a transmission unit;
the transmission unit comprises a main shaft 14, a revolution plate 13 and a gear transmission device 40, wherein a collecting ring 19 is arranged on the main shaft 14;
the gear transmission device 40 comprises a main transmission gear and a planetary transmission gear;
the mechanical stirring unit consists of two planetary stirring shafts 10 and 11 and stirring blade paddles 12 connected with the stirring shafts 10, wherein the planetary stirring shafts 10 and the planetary stirring shafts 11 are symmetrically arranged on a revolution table 13, a main transmission gear and the revolution table 13 are driven to revolve through a main shaft 14, the main transmission gear is meshed with a planetary gear through an intermediate gear, and the planetary gear drives the stirring blade paddles 12 to rotate and revolve around the main shaft 14;
the ultrasonic dispersion unit 8 consists of an ultrasonic stirring rod 15 and an ultrasonic transducer 16, the ultrasonic transducer 16 is fixed on the revolution plate 13, the ultrasonic stirring rod 15 is directly contacted with materials, the ultrasonic stirring rod 15 revolves along with the revolution plate 13 under the action of the main shaft 14, and power supply and revolution are realized through a collecting ring 19 on the main shaft 14 without winding;
the mechanical vibration unit 9 is composed of a mechanical vibration rod 17 and a motor 18, the motor 18 is fixed on the revolution plate 13, the mechanical vibration rod 17 is in direct contact with materials, the mechanical vibration rod 17 revolves along with the revolution plate 13 under the action of the main shaft 14, and power supply and no winding of the revolution are achieved through a collecting ring 19 on the main shaft 14.
Further, the heating unit includes heating jacket 20 and temperature sensor, heating jacket 20 cover is in the agitator kettle outside, heating jacket 20's material is silica gel, pottery or metal, heating jacket 20 supplies power through current-collecting ring 19 on the main shaft 14, temperature sensor is used for detecting the temperature of material in the agitator kettle.
Furthermore, the experiment box 1 is a detachable sealed box body, the top of the experiment box 1 is fixedly provided with an ammonia gas detector 2, a speed reducing motor 21 and a barometer 3, a magnetic coupler 22 and an isolating sleeve 23 are arranged between the speed reducing motor 21 and the experiment box 1, and the magnetic coupler 22 and the isolating sleeve 23 are used for sealing connection of a motor shaft 24 and the experiment box 1.
Further, the lifting structure comprises an upright post 27 at one side of the experimental box 1, a lifting seat 29 is arranged at one side of the upright post 27, the lifting seat 29 is connected with the upright post through a sliding rail, a support arm is fixed on the lifting seat 29, and the tail end of the support arm is fixed with the stirring pot through a thread groove 36;
the inside screw thread dish 33, lead screw 31 and the threaded rod 32 of including of stand 27, the outside of lead screw 31 is equipped with silk covering frame 34, silk covering frame 34 one end is fixed with lift seat 29, lead screw 31 bottom is equipped with screw thread dish 33 and threaded rod 32, screw thread dish 33 meshes with threaded rod 32 mutually, threaded rod 32 is fixed mutually with the handle 28 of stand 27 side, through rotating handle 28 control agitator kettle goes up and down.
Further, the ammonia gas detector 2 is fixed on the upper surface of the experiment box 1, the ammonia gas detector 35 is fixed on the lower side surface of the experiment box 1, the ammonia gas detector 35 is located above the diffuser 5, and the ammonia gas detector 2 and the ammonia gas detector 35 monitor and record the ammonia gas concentration change in the experiment box 1 in real time to obtain the ammonia gas concentration value changing along with time.
Further, boric acid absorption liquid with the mass fraction of 2.0% is contained in the ammonia gas absorption bottle 4, the loading amount of the absorption liquid is more than 1/3 of the capacity of the absorption bottle, and the bottom of the gas path pipeline in the absorption bottle is completely immersed.
The invention also discloses a test method for accelerating the determination of ammonia nitrogen residue in concrete, which comprises the following steps;
s1, preparing a boric acid solution with the mass fraction of 2.0%, measuring 200ml, and filling into an ammonia absorption bottle with the capacity of 250 ml. Preparing the experimental box, installing accessories such as an ammonia gas detector, a barometer, a diffuser and the like, and orderly connecting the experimental box with a speed reducing motor, a gear transmission device, a revolution plate, a fan, an ammonia gas absorption bottle and the like;
s2, fixing the stirring pot, filling concrete with the volume of more than 2/3 of the stirring pot according to the concrete formula, inserting an ultrasonic stirring rod and a mechanical vibrating rod into the concrete material to the depth of more than 1/3 of the total length of the concrete material, then lifting the stirring pot to be attached to the revolution plate, and then rapidly sealing the experiment box;
and S3, closing all connecting pipeline air valves of the experiment box, starting a mechanical stirring device, and setting the stirring revolution speed to be 30r/min for double-planet stirring for 1min so as to uniformly mix all the raw materials of the concrete.
S4, after the initial stirring is finished, changing the mechanical stirring rotating speed, simultaneously starting devices such as ultrasonic dispersion devices, mechanical vibration devices, heating devices and the like, setting corresponding parameters, and then entering a second-stage stirring;
s5, setting electromagnetic valves to automatically open and close all air valves within a set time, and blowing air into the experiment box by starting a fan to ensure that ammonia in the experiment box migrates into the absorption bottle and is absorbed and fixed by boric acid solution;
the air supply fan is started every 5min during the stirring period, all pipeline air valves are required to be opened at the moment, the air quantity is adjusted by observing the condition of air bubbles in the absorption bottle, and the phenomenon that absorption liquid in the absorption bottle is blown out due to overlarge air quantity is avoided.
And S6, after the second-stage stirring is finished, lowering the stirring pot to enable the materials to be separated from the stirring blade, entering a concrete curing stage, and continuing to control the air supply fan according to the method S5. Meanwhile, the new ammonia absorption bottles and absorption liquid are replaced at intervals of 24h, and the continuous collection of ammonia released by the concrete is realized by alternately using a plurality of absorption bottles.
S7, deriving data recorded by the ammonia gas detector, and determining the mass of the ammonia gas in the experimental box by combining the volume of the air in the box, wherein the calculation formula is as follows: m1=17 × (a × V1)/Vm.
Wherein M1 is the mass of ammonia gas in the experimental box, and the unit is ug; a is a numerical value displayed by an ammonia gas detector and the unit is ppm; v1 is the volume of air in the experimental box and has the unit of L; vm is the gas molar volume, 24.5 is carried out under the conditions of 25 ℃ and 101kPa, and the gas molar volume under other conditions can be calculated by an ideal gas equation PV = nRT; 17 is the molar mass of ammonia in g/mol.
S8, measuring the content (M2) of the ammonia nitrogen substances collected in the ammonia gas absorption bottle by adopting a chemical titration method, and finally, obtaining the total amount of the released ammonia gas in the concrete stirring and curing process by using M1+ M2.
And S9, reading results when the display values of the ammonia gas detectors at the top and the bottom of the experiment box are similar under the condition that no fan blows, and taking the results as the ammonia gas concentration value in the experiment box at the moment.
Further, the setting of the mechanical stirring, ultrasonic dispersion, mechanical vibration and heating parameters in the step S4 is determined according to concrete components, and is related to the water-cement ratio (water consumption to cementitious material ratio) and the denitration fly ash blending amount (fly ash to total cementitious material ratio). (1) When the water-to-gel ratio is 0.40-0.50, the mixing amount of the denitration fly ash is within 15%, the corresponding acceleration conditions are that the mechanical stirring revolution speed is 30-60 r/min, the ultrasonic frequency is 15-30 kHz, the ultrasonic power is 400-600 w, the mechanical vibration frequency is 30-40 Hz, the heating temperature is 40-60 ℃, and the second-stage stirring lasts for 10-20 min;
the acceleration condition that the doping amount of the denitration fly ash is 15-30% corresponds to that the mechanical stirring revolution speed is 30-60 r/min, the ultrasonic frequency is 15-30 kHz, the ultrasonic power is 400-800 w, the mechanical vibration frequency is 30-60 Hz, the heating temperature is 40-60 ℃, and the second-stage stirring lasts for 10-20 min;
(2) When the water-to-gel ratio is 0.30-0.40, the mixing amount of the denitration fly ash is within 15%, and the corresponding acceleration conditions are that the mechanical stirring revolution speed is 60-100 r/min, the ultrasonic frequency is 15-30 kHz, the ultrasonic power is 600-1000 w, the mechanical vibration frequency is 80-100 Hz, the heating temperature is 30-50 ℃, and the second-stage stirring lasts for 10-20 min;
the acceleration condition that the mixing amount of the denitration fly ash is 15-30% corresponds to that the mechanical stirring revolution speed is 60-100 r/min, the ultrasonic frequency is 15-30 kHz, the ultrasonic power is 600-1600 w, the mechanical vibration frequency is 80-120 Hz, the heating temperature is 30-50 ℃, and the second-stage stirring lasts for 10-20 min.
Further, the specific chemical titration method in step S7 is as follows:
s71, preparing reagents and instruments, wherein the reagents comprise a methyl red-methylene blue mixed indicator, 0.01-1.0 mol/L standard hydrochloric acid titration solution, a measuring cylinder, an acid burette, a beaker, a conical flask and the like.
Methyl red-methylene blue mixed indicator: the indicator is prepared by mixing a methyl red-ethanol solution with the concentration of 2g/L and a methylene blue-ethanol solution with the concentration of 1g/L in equal volume, and the effective period of the prepared mixed indicator is not more than 7 days;
0.01-1.0 mol/L hydrochloric acid: purchasing 1.0mol/L standard hydrochloric acid titration solution, then diluting the titration solution to different concentrations by using distilled water, and calibrating the diluted hydrochloric acid before use;
and S72, titrating the absorption liquid in each absorption bottle. Adding 2-3 drops of mixed indicator into the absorption bottle, observing the color change of the solution, titrating the absorption solution by adopting a standard hydrochloric acid titration solution, gently shaking the reagent bottle containing the absorption solution in the titration process, and recording the dosage of hydrochloric acid when the solution is changed from yellow green to light red.
S73, calculating the content of ammonia nitrogen substances in the absorption liquid according to the following formula:
MNH3＝ΔVHCl×CHCl×0.017×106
wherein MNH3 represents the content of ammonia nitrogen substances measured by the absorption liquid, and the unit is g; Δ VHCl represents the hydrochloric acid consumption in ml at the end of the titration; CHCl represents the concentration of titrated hydrochloric acid in mol/L.
Compared with the prior art, the invention has the beneficial effects that:
(1) The material stirring and lifting mechanism is arranged in the closed experiment box, so that the simulation of the concrete stirring and curing process is realized, and meanwhile, the test method for measuring the ammonia release amount in the concrete is further optimized.
(2) The proposal of intermittently opening the fan and comprehensively judging the distribution uniformity of ammonia in the experimental box by the multi-part ammonia gas detector is provided, the problems that the gas flow in the experimental box causes the uneven distribution of ammonia in the experimental box and the ammonia gas detector can not accurately measure the ammonia gas concentration in the box due to the continuous air supply of the fan in the prior art are solved, and then the continuous measurement of the ammonia gas release amount from the concrete stirring to the whole condensation hardening process is finally realized, and the accuracy of the measurement result is improved.
(3) By providing a synergistic excitation technical means of applying ultrasonic dispersion, mechanical vibration and heating coupling in the concrete stirring process, the ammonia nitrogen substance in the concrete is greatly improved to generate ammonium-alkali reaction degree, ammonia volatilization in the concrete is accelerated, ammonia nitrogen substance residue in the concrete can be determined in a short time, and the test period is shortened.
(4) By the test device and the test method, the ammonia gas release rule of the whole process from stirring to hardening of the concrete can be mastered, and meanwhile, by the accelerated determination method, the determination period is shortened, and the actual production and construction of the denitration fly ash in the concrete can be conveniently guided.
(5) The device is simple and easy to operate, and the test method is simple, reliable and quick, and has popularization significance and economic and social effects.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a front view of a testing apparatus for accelerated determination of residual ammonia nitrogen in concrete according to the present invention.
FIG. 2 is a reverse view of a test apparatus for accelerated determination of ammonia nitrogen species remaining in concrete.
Fig. 3 is a schematic structural view of the pillar.
FIG. 4 is a time-dependent curve of the mass of ammonia gas in the laboratory box M.
FIG. 5 is a curve showing the cumulative mass of ammonia absorbed by the absorber flask as M flasks varied with time.
FIG. 6 is a curve showing the variation of ammonia release in concrete in M boxes and M bottles over time.
Reference numerals
1. An experimental box;
2. an ammonia gas detector;
3. a barometer;
4. an ammonia gas absorption bottle;
5. a diffuser;
6. a flow controller;
7. a fan;
8. an ultrasonic dispersion unit;
9. a mechanical vibration unit;
10. a planetary stirring shaft;
11. a planetary stirring shaft;
12. stirring blade paddles;
13. a revolution plate;
14. a main shaft;
15. an ultrasonic stirring rod;
16. an ultrasonic transducer;
17. a mechanical vibrating rod;
18. a motor;
19. a collector ring;
20. heating a jacket;
21. a reduction motor;
22. a magnetic coupler;
23. an isolation sleeve;
24. a motor shaft;
25. an exhaust hole;
26. sealing the threading hole;
27. a column;
28. a handle;
29. a lifting seat;
30. a stirred pot;
31. a screw rod;
32. a threaded rod;
33. a threaded disc;
34. a wire sleeve frame;
35. an ammonia gas detector;
36. a thread groove;
37. an air valve;
38. a flow stopper;
39. a breather pipe;
40. a gear transmission;
41. a load shaft;
42. a slide rail.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.
The present invention will be described in further detail with reference to the accompanying drawings.
Example 1
As shown in FIG. 1, the test device for accelerated determination of ammonia nitrogen residue in concrete comprises a test box 1, an ammonia gas monitoring and absorbing system and an air supply system, wherein the test box 1 comprises a material stirring mechanism, a lifting mechanism and a heating structure;
the ammonia monitoring and absorption system comprises:
the ammonia gas detectors are fixed on the experiment box 1 and used for detecting the concentration of ammonia gas in the experiment box 1, and the number of the ammonia gas detectors is multiple;
the barometer 3 is fixed on the experimental box 1;
the ammonia absorption bottle 4 is connected with the exhaust hole 25 above the heat preservation box 1 through a gas path pipeline, and the gas path pipeline is provided with a gas valve 37 and a flow stopper 38;
the air supply system comprises an air diffuser 5, a flow controller 6, a ventilating pipe 39 and an air supply fan 7, wherein the air diffuser 5 is fixed at the bottom of the experiment box and is connected with the flow controller 6 and the air supply fan 7 outside the experiment box 1 through the ventilating pipe 39.
Further, the material stirring mechanism consists of a mechanical stirring unit, an ultrasonic dispersion unit 8, a mechanical vibration unit 9 and a transmission unit;
the transmission unit comprises a main shaft 14, a revolution plate 13 and a gear transmission device 40, wherein a collecting ring 19 is arranged on the main shaft 14;
the gear transmission device 40 comprises a main transmission gear and a planetary transmission gear;
the mechanical stirring unit consists of two planetary stirring shafts 10 and 11 and stirring blades 12 connected with the stirring shafts 10, wherein the planetary stirring shafts 10 and the planetary stirring shafts 11 are symmetrically arranged on a revolution plate 13, a main transmission gear and the revolution plate 13 are driven to revolve through a main shaft 14, the main transmission gear is meshed with a planetary gear through an intermediate gear, and the planetary gear drives the stirring blades 12 to rotate and revolve around the main shaft 14;
the ultrasonic dispersion unit 8 consists of an ultrasonic stirring rod 15 and an ultrasonic transducer 16, the ultrasonic transducer 16 is fixed on the revolution plate 13, the ultrasonic stirring rod 15 is directly contacted with materials, the ultrasonic stirring rod 15 revolves along with the revolution plate 13 under the action of the main shaft 14, and power supply and revolution are realized through a collecting ring 19 on the main shaft 14 without winding;
the mechanical vibration unit 9 is composed of a mechanical vibration rod 17 and a motor 18, the motor 18 is fixed on the revolution plate 13, the mechanical vibration rod 17 is in direct contact with materials, the mechanical vibration rod 17 revolves along with the revolution plate 13 under the action of the main shaft 14, and power supply and revolution are realized through a collecting ring 19 on the main shaft 14 without winding.
Further, the heating unit includes heating jacket 20 and temperature sensor, the heating jacket 20 cover is in the agitator kettle outside, the material of heating jacket 20 is silica gel, pottery or metal, heating jacket 20 supplies power through current-collecting ring 19 on main shaft 14, temperature sensor is used for detecting the temperature of material in the agitator kettle.
Furthermore, the experiment box 1 is a detachable sealed box body, the top of the experiment box 1 is fixedly provided with an ammonia gas detector 2, a speed reducing motor 21 and a barometer 3, a magnetic coupler 22 and an isolating sleeve 23 are arranged between the speed reducing motor 21 and the experiment box 1, and the magnetic coupler 22 and the isolating sleeve 23 are used for sealing connection of a motor shaft 24 and the experiment box 1.
The lifting structure comprises an upright post 27 at one side of the experimental box 1, a lifting seat 29 is arranged at one side of the upright post 27, the lifting seat 29 is connected with the upright post through a sliding rail, a support arm is fixed on the lifting seat 29, and the stirring pot is fixed at the tail end of the support arm through a thread groove 36;
as shown in FIG. 3, the experimental box 1 comprises a column 27 completely attached to the experimental box, a handle 28 for adjusting the height of the mixing pot 30 is provided on the side of the column 27, a sliding groove and a lifting base 29 are provided on the front side of the column 27, the lifting base 29 is installed in a sliding rail manner, and an arm is fixed on the lifting base 29, and a threaded groove 36 for fixing the mixing pot 30 is provided at the end of the arm. In addition, lead screw and threaded rod 32 are installed with the reel mode in the inside of stand 27, the screw 34 frame is installed through the helicitic texture in the outside of lead screw 31, and screw 34 frame one end is fixed with lift seat 29 through the bolt, the bottom of lead screw 31 is equipped with screw dish 33 and threaded rod 32, and screw dish 33 meshes with threaded rod 32 mutually, and the one end of threaded rod 32 extends to the stand 27 outside, is fixed mutually with handle 28 on the stand 27 side.
The screw rod 31 is rotated by rotating the handle on the side surface of the upright post 27 through the transmission of the threaded rod 32 and the threaded disc 33, so that the screw sleeve frame 34 and the lifting seat 29 are driven to move in the vertical direction, and the lifting process of the stirring pot 30 is controlled and fixed by combining the self-locking characteristic of any angle of the threaded rod 32. By means of the design of the sliding groove on the front surface of the upright post 27, the lifting seat 29 extends to the inside of the upright post 27 and is fixed with the thread sleeve frame 34, so that the stability of the lifting seat 29 in the vertical moving process is improved.
The ammonia gas detector 2 is fixed on the upper surface of the experiment box 1, the ammonia gas detector 35 is fixed on the lower side surface of the experiment box 1, the ammonia gas detector 35 is positioned above the air diffuser 5, and the ammonia gas detector 2 and the ammonia gas detector 35 monitor and record the ammonia gas concentration change in the experiment box 1 in real time to obtain the ammonia gas concentration value changing along with time.
The ammonia gas absorption bottle 4 is filled with boric acid absorption liquid with the mass fraction of 2.0%, the loading amount of the absorption liquid is more than 1/3 of the capacity of the absorption bottle, and the bottom of a gas circuit pipeline in the absorption bottle is completely immersed.
Example 2
A test method for accelerating determination of ammonia nitrogen substance residue in concrete comprises pouring concrete raw materials into a stirring pot of a test box, packaging, and accelerating volatilization and determination of ammonia nitrogen substance residue in concrete by one or more, one group or a plurality of groups of stirring forms of planetary stirring, ultrasonic stirring and heating stirring.
The mixing proportion of the concrete is shown in table 1, the denitration ash can smell obvious ammonia smell, and the ammonia content (calculated by NH 3) is 180-220 mg/kg after multiple times of detection.
TABLE 1 concrete test mix proportion
The test method for accelerating determination of ammonia nitrogen substance residue in concrete comprises the following specific steps:
s1) preparing a boric acid solution with the mass fraction of 2.0%, and measuring a plurality of 200ml solutions to be injected into a plurality of ammonia absorption bottles. Preparing an experimental box, installing accessories such as an ammonia gas monitor, a barometer, a flow controller, a diffuser and the like, and orderly connecting the experimental box with a motor, a gear box, a planetary disc, a fan, an ammonia gas absorption bottle, a vent valve and the like;
s2) pouring concrete raw materials such as water, additives, cement, gravel and the like or fresh concrete into the stirring pot, and then fixing the stirring pot. Rotating a handle at the side of the upright column, lifting the stirring pot to be completely attached to the planetary disc, and then completely packaging the experimental box;
s3) opening each air valve, starting a fan, adjusting a flow controller, setting the air flow in the box, checking the air tightness in the box and ensuring that each air channel is normal;
s4) starting the mechanical stirring device, and after the stirring time and the rotating speed are set, starting planetary stirring by the equipment;
s5) starting the ultrasonic dispersion and heating device according to the requirement, correspondingly setting the ultrasonic power, the ultrasonic starting time and the ultrasonic finishing time, and starting the corresponding device after the heating temperature and the heating starting time and the heating finishing time are set;
s6) after the stirring is finished, rotating a handle beside the upright post, and lowering the stirring pot to enter a concrete curing stage;
s7) ammonia released in the concrete stirring and curing process is discharged from a vent hole in a top cover of the experiment box under the driving of air supply from bottom to top by an air diffuser, and then is continuously absorbed by boric acid absorption liquid in an ammonia absorption bottle. The absorption bottles and the absorption liquid are replaced at intervals, and a plurality of absorption bottles are used alternately, so that the continuous collection of released ammonia gas is realized;
s8) deriving data recorded by the ammonia gas monitor, and determining the mass of ammonia gas in the experimental box by combining the volume of air in the box, wherein the calculation formula is as follows: m bins =17 × (a × V bins)/Vm. Wherein, M box is the mass of ammonia gas in the experimental box, and the unit is ug; a is a numerical value displayed by an ammonia gas monitor and has a unit of ppm; v box is the volume of air in the experiment box, and the unit is L; vm is the gas molar volume, 24.5 is carried out under the conditions of 25 ℃ and 101kPa, and the gas molar volume under other conditions can be calculated by an ideal gas equation PV = nRT; and 17 is the ammonia gas molar mass with the unit of g/mol.
Meanwhile, the content M bottle of the ammonia nitrogen substances collected by the absorption bottle is determined by a chemical titration method, and the M box and the M bottle are the mass of the ammonia gas released in the concrete stirring and curing process.
The specific method of chemical titration analysis comprises the following steps:
s81, preparing reagents and instruments, including a methyl red-methylene blue mixed indicator, 0.01-1.0 mol/L dilute hydrochloric acid, a measuring cylinder, an acid burette, a beaker, a conical flask and the like. Methyl red-methylene blue mixed indicator: the indicator is prepared by mixing a methyl red-ethanol solution with the concentration of 2g/L and a methylene blue-ethanol solution with the concentration of 1g/L in equal volume, wherein the existence time of the mixed indicator is not more than 7 days; 0.01-1.0 mol/L hydrochloric acid: purchasing 1.0mol/L standard hydrochloric acid solution, then diluting the hydrochloric acid solution into hydrochloric acid solutions with different concentrations by using distilled water, and calibrating the diluted hydrochloric acid solution before use;
s82, titrating the absorption liquid in each absorption bottle. Adding 2-3 drops of mixed indicator into the absorption bottle, observing the color change of the solution, titrating the absorption solution by adopting hydrochloric acid solution, gently shaking the reagent bottle containing the absorption solution in the titration process, and recording the dosage of the hydrochloric acid when the solution is changed from yellow green to light red.
S83, calculating the content of ammonia nitrogen substances in the absorption liquid according to the following formula: MNH3= Δ VHCl × CHCl × 0.017 × 106. Wherein MNH3 represents the content of ammonia nitrogen substances measured by the absorption liquid, and the unit is g; Δ VHCl represents the hydrochloric acid consumption in ml at the end of the titration; CHCl represents the concentration of titrated hydrochloric acid and is expressed in mol/L.
TABLE 2 Experimental design for accelerated determination of residual ammonia nitrogen in concrete
Note: the concrete mixing amount of the specific group and all the test groups is 20L;
in combination with the results of the experiment shown in FIGS. 4-6, it can be seen that:
(1) The comparison of the comparison group and the test group 1 shows that a large amount of ammonia is released in the concrete stirring process, and the total ammonia release amount (comparison group) for completing concrete stirring and maintenance in the test box under the same condition is obviously higher than the result of indoor stirring and then placing the test box for maintenance.
(2) The comparison of the comparison group and the test group 2 shows that the volatilization of ammonia nitrogen substances in the concrete is greatly promoted by the cooperation of the ultrasonic dispersion, the heating and the mechanical stirring. The ammonia content of the denitration ash used in the test is 180-200 mg/kg through inspection, the dosage of the single-material concrete denitration ash in the test design is 80kg, and the theoretical ammonia content of the concrete is 288000-32000 g according to the calculation of 20L. Therefore, the method can more accurately measure the ammonia nitrogen residues in the concrete.
The above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still 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 corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. The utility model provides a test device that ammonia nitrogen material is remained in accelerated survey concrete, includes experimental box (1), ammonia monitoring and absorption system and air supply system, its characterized in that:
the experiment box (1) comprises a material stirring mechanism, a lifting mechanism and a heating structure;
the ammonia monitoring and absorption system comprises:
the ammonia gas detectors are fixed on the experiment box (1) and used for detecting the concentration of ammonia gas in the experiment box (1), and the number of the ammonia gas detectors is multiple;
the air pressure meter (3), the air pressure meter (3) is fixed on the experiment box (1);
the ammonia absorption bottle (4) is connected with the exhaust hole (25) above the heat preservation box (1) through a gas path pipeline, and the gas path pipeline is provided with a gas valve (37) and a flow stopper (38);
the air supply system is composed of an air diffuser (5), a flow controller (6), a ventilating pipe (39) and an air supply fan (7), wherein the air diffuser (5) is fixed at the bottom of the experiment box and is connected with the flow controller (6) and the air supply fan (7) outside the experiment box (1) through the ventilating pipe (39).
2. The test device for accelerating the determination of ammonia nitrogen substance residue in concrete according to claim 1, wherein the material stirring mechanism is composed of a mechanical stirring unit, an ultrasonic dispersion unit (8), a mechanical vibration unit (9) and a transmission unit;
the transmission unit comprises a main shaft (14), a revolution disc (13) and a gear transmission device (40), and a collecting ring (19) is arranged on the main shaft (14);
the gear transmission device (40) comprises a main transmission gear and a planetary transmission gear;
the mechanical stirring unit consists of two planetary stirring shafts (10) and (11) and stirring blade paddles (12) connected with the stirring shafts (10), wherein the planetary stirring shafts (10) and the planetary stirring shafts (11) are symmetrically arranged on a revolution plate (13), a main transmission gear and the revolution plate (13) are driven to revolve through a main shaft (14), the main transmission gear is meshed with a planetary gear through an intermediate gear, and the planetary gear drives the stirring blade paddles (12) to rotate and revolve around the main shaft (14);
the ultrasonic dispersion unit (8) consists of an ultrasonic stirring rod (15) and an ultrasonic transducer (16), the ultrasonic transducer (16) is fixed on the revolution table (13), the ultrasonic stirring rod (15) is directly contacted with materials, the ultrasonic stirring rod (15) revolves along with the revolution table (13) under the action of a main shaft (14), and power supply and no winding of revolution are realized through a power collecting ring (19) on the main shaft (14);
the mechanical vibration unit (9) is composed of a mechanical vibration rod (17) and a motor (18), the motor (18) is fixed on the revolution plate (13), the mechanical vibration rod (17) is in direct contact with materials, the mechanical vibration rod (17) revolves along with the revolution plate (13) under the action of the main shaft (14), and power supply and no winding of the revolution are achieved through a power collecting ring (19) on the main shaft (14).
3. The test device for accelerating the determination of ammonia nitrogen substance residue in concrete according to claim 1, wherein the heating unit comprises a heating jacket (20) and a temperature sensor, the heating jacket (20) is sleeved outside the mixing kettle, the material of the heating jacket (20) is silica gel, ceramic or metal, the heating jacket (20) is powered by a power collecting ring (19) on the main shaft (14), and the temperature sensor is used for detecting the temperature of materials in the mixing kettle.
4. The test device for accelerated determination of ammonia nitrogen residue in concrete according to claim 1, wherein the experimental box (1) is a detachable sealed box body, the top of the experimental box (1) is fixedly provided with an ammonia gas detector (2), a speed reducing motor (21) and a gas pressure gauge (3), a magnetic coupler (22) and an isolating sleeve (23) are arranged between the speed reducing motor (21) and the experimental box (1), and the magnetic coupler (22) and the isolating sleeve (23) are used for sealing connection of a motor shaft (24) and the experimental box (1).
5. The test device for accelerating the determination of ammonia nitrogen substance residue in concrete according to claim 1, wherein the lifting structure comprises a column (27) on one side of the test box (1), a lifting seat (29) is arranged on one side of the column (27), the lifting seat (29) is connected with the column through a sliding rail, a support arm is fixed on the lifting seat (29), and the stirring pot (30) is fixed at the tail end of the support arm through a threaded groove (40);
stand (27) are inside including thread dish (33), lead screw (31) and threaded rod (32), the outside of lead screw (31) is equipped with silk cover frame (34), silk cover frame (34) one end is fixed with lift seat (29), lead screw (31) bottom is equipped with thread dish (33) and threaded rod (32), thread dish (33) meshes with threaded rod (32) mutually, threaded rod (32) are fixed mutually with handle (28) of stand (27) side, through rotating handle (28) control agitated kettle (30) go up and down.
6. The test device for accelerating the determination of ammonia nitrogen residue in concrete according to claim 1, wherein the ammonia gas detector (2) is fixed on the upper surface of the test box (1), the ammonia gas detector (35) is fixed on the lower side surface of the test box (1), the ammonia gas detector (35) is located above the diffuser (5), and the ammonia gas detector (2) and the ammonia gas detector (35) monitor and record the ammonia gas concentration change in the test box (1) in real time to obtain the ammonia gas concentration value changing with time.
7. The test device for accelerating determination of ammonia nitrogen substance residue in concrete according to claim 1, characterized in that the ammonia gas absorption bottle (4) contains boric acid absorption liquid with mass fraction of 2.0%, the loading amount of the absorption liquid is more than 1/3 of the capacity of the absorption bottle, and the bottom of the gas path pipeline in the absorption bottle is completely immersed.
8. A test method for accelerated determination of residual ammonia nitrogen substances in concrete by using the test apparatus for accelerated determination of residual ammonia nitrogen substances in concrete according to any one of claims 1 to 7, characterized by comprising the steps of;
s1, preparing a boric acid solution with the mass fraction of 2.0%, measuring 200ml, and filling into an ammonia absorption bottle with the capacity of 250 ml. Preparing the experiment box, installing accessories such as an ammonia gas detector, a barometer, a diffuser and the like, and orderly connecting the experiment box with a speed reduction motor, a gear transmission device, a revolution disc, a fan, an ammonia gas absorption bottle and the like;
s2, fixing the stirring pot, filling concrete with the volume of more than 2/3 of the stirring pot according to the concrete formula, inserting an ultrasonic stirring rod and a mechanical vibrating rod into the concrete material to the depth of more than 1/3 of the total length of the concrete material, then lifting the stirring pot to be attached to the revolution plate, and then rapidly sealing the experiment box;
and S3, closing all connecting pipeline air valves of the experiment box, starting a mechanical stirring device, and setting the stirring revolution speed to be 30r/min for double-planet stirring for 1min so as to uniformly mix all the raw materials of the concrete.
S4, after the initial stirring is finished, changing the mechanical stirring rotating speed, simultaneously starting devices such as ultrasonic dispersion devices, mechanical vibration devices, heating devices and the like, setting corresponding parameters, and then entering a second-stage stirring;
s5, setting an electromagnetic valve to automatically open and close each air valve within a set time, and blowing air into the experiment box by starting a fan to make ammonia in the experiment box migrate into the absorption bottle and be absorbed and fixed by boric acid solution;
and during stirring, the air supply fan is started every 5min, all pipeline air valves are required to be opened at the moment, and the air quantity is adjusted by observing the condition of air bubbles in the absorption bottle, so that the phenomenon that absorption liquid in the absorption bottle is blown out due to overlarge air quantity is avoided.
And S6, after the second-stage stirring is finished, lowering the stirring pot to enable the materials to be separated from the stirring blade, entering a concrete curing stage, and continuing to control the air supply fan according to the method S5. Meanwhile, the new ammonia absorption bottles and absorption liquid are replaced at intervals of 24h, and the continuous collection of ammonia released by the concrete is realized by alternately using a plurality of absorption bottles.
S7, deriving data recorded by the ammonia gas detector, and determining the mass of the ammonia gas in the experimental box by combining the volume of the air in the box, wherein the calculation formula is as follows: m1=17 × (a × V1)/Vm.
Wherein M1 is the mass of ammonia gas in the experimental box, and the unit is ug; a is a numerical value displayed by an ammonia gas detector and the unit is ppm; v1 is the volume of air in the experimental box and has the unit of L; vm is the gas molar volume, 24.5 under the conditions of 25 ℃ and 101kPa, and the gas molar volume under other conditions can be calculated by an ideal gas equation PV = nRT; 17 is the molar mass of ammonia in g/mol.
And S8, measuring the content (M2) of the ammonia nitrogen substances collected in the ammonia gas absorption bottle by adopting a chemical titration method, and finally, obtaining M1+ M2 as the total amount of the released ammonia gas in the concrete stirring and curing process.
And S9, reading results when the display values of the ammonia gas detectors at the top and the bottom of the experiment box are close to each other under the condition that no fan blows, and taking the results as the ammonia gas concentration value in the experiment box at the moment.
9. The test method for accelerated determination of residual ammonia nitrogen in concrete according to claim 8, wherein the mechanical stirring, ultrasonic dispersion, mechanical vibration and heating parameters in step S4 are set according to concrete components, and are related to water-cement ratio (water consumption and cementing material ratio) and denitration fly ash content (fly ash to total cementing material ratio).
(1) When the water-adhesive ratio is 0.40 to 0.50, the mixing amount of the denitration fly ash is within 15 percent, the corresponding acceleration conditions are that the mechanical stirring revolution speed is 30 to 60r/min, the ultrasonic frequency is 15 to 30kHz, the ultrasonic power is 400 to 600w, the mechanical vibration frequency is 30 to 40Hz, the heating temperature is 40 to 60 ℃, and the stirring is continued for 10 to 20min in the second stage;
the acceleration condition corresponding to the mixing amount of the denitration fly ash of 15 to 30 percent is that the mechanical stirring revolution speed is 30 to 60r/min, the ultrasonic frequency is 15 to 30kHz, the ultrasonic power is 400 to 800w, the mechanical vibration frequency is 30 to 60Hz, the heating temperature is 40 to 60 ℃, and the stirring is continued for 10 to 20min in the second stage;
(2) When the water-adhesive ratio is 0.30 to 0.40, the mixing amount of the denitration fly ash is within 15 percent, the corresponding acceleration conditions are that the mechanical stirring revolution speed is 60 to 100r/min, the ultrasonic frequency is 15 to 30kHz, the ultrasonic power is 600 to 1000w, the mechanical vibration frequency is 80 to 100Hz, the heating temperature is 30 to 50 ℃, and the stirring is continued for 10 to 20min in the second stage;
the denitration fly ash mixing amount is 15-30% under the corresponding acceleration condition that the mechanical stirring revolution speed is 60-100r/min, the ultrasonic frequency is 15-30kHz, the ultrasonic power is 600-1600 w, the mechanical vibration frequency is 80-120Hz, the heating temperature is 30-50 ℃, and the stirring is continued for 10-20min in the second stage.
10. The test method for accelerating the determination of ammonia nitrogen substance residue in concrete according to claim 8, wherein the chemical titration method in step S7 is as follows:
s71, preparing reagents and instruments, wherein the reagents comprise a methyl red-methylene blue mixed indicator, a standard hydrochloric acid titration solution of 0.01 to 1.0mol/L, a measuring cylinder, an acid burette, a beaker, a conical flask and the like.
Methyl red-methylene blue mixed indicator: the indicator is prepared by isovolumetrically mixing a methyl red-ethanol solution with the concentration of 2g/L and a methylene blue-ethanol solution with the concentration of 1g/L, and the effective period of the prepared mixed indicator is not more than 7 days;
0.01 to 1.0mol/L hydrochloric acid: purchasing 1.0mol/L standard hydrochloric acid titration solution, then diluting the titration solution to different concentrations by using distilled water, and calibrating the diluted hydrochloric acid before use;
and S72, titrating the absorption liquid in each absorption bottle. Adding 2~3 drops of mixed indicator into the absorption bottle, observing the color change of the solution, titrating the absorption solution by using a standard hydrochloric acid titration solution, gently shaking the reagent bottle containing the absorption solution in the titration process, and recording the dosage of hydrochloric acid when the solution is changed from yellow green to light red.
S73, calculating the content of ammonia nitrogen substances in the absorption liquid according to the following formula:
MNH3=ΔVHCl×CHCl×0.017×106
wherein MNH3 represents the content of ammonia nitrogen substances measured by the absorption liquid, and the unit is mug; Δ VHCl represents the hydrochloric acid consumption in ml at the end of the titration; CHCl represents the concentration of titrated hydrochloric acid in mol/L.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116338152A (en) * | 2023-05-31 | 2023-06-27 | 湖北迪飞商品混凝土有限公司 | Device and method for rapidly measuring chloride ion content of concrete |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116338152A (en) * | 2023-05-31 | 2023-06-27 | 湖北迪飞商品混凝土有限公司 | Device and method for rapidly measuring chloride ion content of concrete |
| CN116338152B (en) * | 2023-05-31 | 2023-08-22 | 湖北迪飞商品混凝土有限公司 | Device and method for rapidly measuring chloride ion content of concrete |
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