The apparatus and method of nitrogen content in a kind of Fast Measurement edible vegetable oil
The present invention relates to the measurement of nitrogen content in edible vegetable oil, refer in particular to the apparatus and method of nitrogen content in a kind of Fast Measurement edible vegetable oil.
Though nitrogen-charging fresh-keeping technology is existing application in edible oil field, but the quantitative detection of the nitrogen amount of being filled with in grease and nitrogen are dissolved in fast to hybrid mode few people's research of edible vegetable oil, customary practice is in the industry to be filled with by rule of thumb, being filled with time and the amount of being filled with all cannot be quantitative, causes the low and energy dissipation of production efficiency.Because whether nitrogen gas dissolved amount in packing oil product is sufficient without corresponding detection method, so often there is the phenomenon of oil product oil bottle distortion on shelf, this has brought very large infringement to Oils and fats enterprise, and the method for therefore inventing nitrogen content in a kind of Fast Measurement edible vegetable oil has very important realistic meaning.
The method of measuring at present gas solubility in liquid adopts volumetric method more, but (its mole fraction is roughly 10 because the solubleness of gas in liquid is generally very little
5 between), thereby this brings very large difficulty to experimental implementation, and very high to detecting instrument requirement, otherwise experimental result error is larger.And in existing mensuration liquid, the instrument of gas content and Method And Principle are all based on the Ideal-Gas Equation, to record the volume of liquid absorption gas, but the mensuration of nitrogen content in the inapplicable edible vegetable oil of these instruments, major defect has 3 points: the one, and it is longer that liquid phase reaches time of balance, is unfavorable for fast detecting; The 2nd, the measurement means when lacking liquid phase and reaching balance; The 3rd, cannot measure the gas flow having contained in liquid.
Summary of the invention
The object of the invention is for the shortcoming existing in background technology and problem improvement and bring new ideas in addition, a kind of monitoring that edible vegetable oil fills nitrogen process that is applicable to is provided, by adjusting the best, fill nitrogen oil temperature and can make vegetable oil absorb fast and efficiently nitrogen, not only guaranteed product quality but also saved the device of nitrogen content in the Fast Measurement edible vegetable oil of production cost.
Another object of the present invention is to provide a kind of method of utilizing nitrogen content in said apparatus Fast Measurement edible vegetable oil.
Apparatus of the present invention comprise magnetic stirrer, are placed on the thermostatic bath showing with temperature on magnetic stirrer, and are arranged on the cylinder body in isothermal liquid in the thermostatic bath showing with temperature, wherein:
Filling edible vegetable oil in cylinder body, top arranges gland bonnet component sealing cylinder body, on gland bonnet assembly, by pipeline, be connected with one end and stretch into the differential manometer in edible vegetable oil upper space in cylinder body, vacuum pump, gas composition instrument and nitrogen cylinder, on gland bonnet assembly, also by pipeline, be connected with ebullator and thermometer;
Described ebullator is provided with oil inlet pipe and flowline, and wherein oil inlet pipe stretches into cylinder body edible vegetable oil bottom, and flowline stretches in the interior edible vegetable oil upper space of cylinder body, and the oil-out of flowline is provided with spray head;
Described thermometer comprises the oil temperature signal piping stretching in cylinder body edible vegetable oil and stretches into the interior space temperature signal piping of the bottle in edible vegetable oil upper space in cylinder body.
Internal cavities and the ambient atmosphere of gland bonnet component sealing of the present invention and partition cylinder body, gland bonnet assembly comprises O-ring seal, clasp, bottle cap and bottle stopper, and the connecting line inserting end of described differential manometer, vacuum pump, gas composition instrument, ebullator, nitrogen cylinder and thermometer all stretches in cylinder body by bottle stopper.Described differential manometer, gas composition instrument and thermometer are all connected computer and read and recording detection data by computer.Described cylinder body is the flat glass bottle with scale, the stentplacement that cylinder body arranges by bottom in isothermal liquid, and at the bottom of the food plant oil level in cylinder body in isothermal liquid liquid level.Described cylinder base is 2-3cm with the thermostatic bath distance from bottom showing with temperature.
The inventive method comprises the following steps:
1) computer and differential manometer, thermometer and gas composition instrument connected to machine and open, the cylinder body of known volume being put into the thermostatic bath showing with temperature, taking off bottle stopper and connecting line, the edible vegetable oil of known volume is slowly injected, by bottle stopper jam-pack, buckle well clasp again, record initial temperature T
0, pressure P
0, gas volume V
0with gas composition situation;
2) open ebullator, governing speed, makes edible vegetable oil by spray head, be vaporific spray by oil inlet pipe, flowline, observes pressure reduction, temperature and gas change of component curve, and after liquid phase reaches balance, pressure reduction is constant, record pressure P now
1and temperature T
1, by equation of gas state n=PV/RT, wherein R is constant, and the gas in sealed cylinder block is that constant is constant, and n is definite value, the equation of gas state P in the time of can releasing original state and equilibrium state thus
1, gas volume V while calculating equilibrium state
1, the amount that obtains this known volume edible oil absorption gas under this pressure and temperature environment is V
0, then divided by edible oil volume, obtain the amount S of unit edible vegetable oil absorption gas under this pressure and temperature environment
inhale, amount that can also dissolved gases;
3) above-mentioned suction there is is the cylinder body of the edible vegetable oil of gas move on large capacity magnetic stirrer, connect vacuum pump, while vacuumize, stir, the gas in edible vegetable oil is all extracted out; Then repeating 2) step operation is filled with nitrogen, makes liquid phase reach secondary balancing; Altogether to dissolve the amount S of nitrogen be saturation solubility to the volumescope unit of calculating edible vegetable oil by the equation of gas state and known edible vegetable oil again, the finally actual nitrogen amount containing in the unit's of drawing edible vegetable oil, the i.e. actual nitrogen amount=S-S containing in unit edible vegetable oil
Advantage of the present invention and beneficial effect:
1, first Application of the present invention, in edible oil field, can not only be measured gas content in edible oil, can also measure a bottle content for interior gas different component.
2, the present invention, by spray and the comprehensive utilization of stirring, makes oil droplet be vaporific by spray head and scatters, and regulates rate of circulation that gas is fully contacted with liquid, reaches gas-liquid phase equilibrium within the shortest time, has greatly shortened detection time.
3, detection speed of the present invention is fast, and result is accurate.Because gas-liquid can fully be mixed at short notice, the time of vapor liquid equilibrium is very short, generally, in 30 minutes, during gas-liquid phase equilibrium, can reflect by the change curve on computer, and data recording is accurate.Utilize the equation of gas state, can accurately obtain experiment front and back gas volume changing value.
4, by the present invention, can first calculate the gas flow (actual meltage) that can also dissolve or separate out in fuel-displaced, vacuumized again and extracted all gas that it contains, and then be filled with nitrogen it is reached after secondary balancing, can calculate the saturated meltage of gas, both differences are the gas flows having contained in oil.
The present invention not only can measure the variation of nitrogen gas dissolved amount and upper sheaf space gas composition in edible vegetable oil, is also applicable to the mensuration of other gas saturation solubility and actual meltage in different liquids.
Accompanying drawing explanation
Fig. 1 is apparatus of the present invention structural representations.
Design concept of the present invention:
Cylinder body 11 of the present invention is connected into and out of oil pipe with ebullator 7, in cylinder body 11 bottoms, there is oil inlet pipe 17, at cylinder body 11 tops, there is flowline 18, flowline 18 ends are connected with spray head 10, cylinder port O-ring seal is closely connected with bottle stopper 3, bottle sealing encloses sealing function, and bottle internal cavity and ambient atmosphere are separated, and guarantees that the interior sealing of cylinder body 11 is good.Cylinder body 11 is placed on to 12 li of the thermostatic baths that show with temperature, and three small racks 15 are arranged at cylinder body 11 bottoms, and making cylinder body 11 bottoms is 2-3cm from the distance of thermostatic bath 12 bottoms that show with temperature, guarantees that nitrogen and edible vegetable oil are in isoperibol.In the bottle on vegetable oil 14 upper stratas, the temperature in space is measured and is connected with computer by thermometer 9 with vegetable oil 14 oil temperatures, and in bottle, the pressure in space is changed by precision pressure gauge and differential manometer 4 monitoring pressures, and differential manometer 4 is connected with computer, and during balance, pressure reduction is constant.In bottle, space is connected with gas composition instrument 6, for measuring a bottle variation for interior space gas composition.The vegetable oil that has contained gas can be placed on cylinder body 11 on large capacity magnetic stirrer 16, while stir, vacuumizes, and after the gas in oil is all extracted out, is filled with nitrogen again, by circulation, makes liquid phase reach balance.
Groundwork principle of the present invention is to be filled with nitrogen after the gas in edible vegetable oil is all extracted out again, by circulation, makes liquid phase reach balance, records saturated inspiratory capacity.Directly edible vegetable oil is circulated air-breathing, reach after balance and record the gas flow sucking again, the former deducts the latter and is the actual gas flow containing in oil.
Below in conjunction with drawings and Examples, the invention will be further described.
As shown in Figure 1, all pipelines and device connect.Open the stopper that is connected with pipeline, slowly edible vegetable oil is injected to cylinder body, by the scale on cylinder body, can read the volume (V oil=5.01L) of edible vegetable oil, filled in rapidly bottle stopper, buckle well clasp, now record initial temperature, pressure, chamber inner volume and gas composition situation, record records now the pressure P in bottle by differential manometer
0=101.12 KPa, thermometer records temperature T in cavity
0=15 ℃+273=288K, by cylinder body scale, can calculate a bottle internal cavity volume V
0=6.210 L, can measure the content of each component gas, N by gas composition instrument
2=22%.Open ebullator, adjusting circulation pump speed is 3000r/min, makes oil droplet be vaporific spray, observes pressure reduction, temperature and gas change of component curve, and after liquid phase reaches balance, pressure reduction is constant, record pressure P now
1=101.72 KPa, temperature=16 ℃+273=289K, the content of each component gas, N
2=19%, by the equation of gas state, can be calculated the amount of dissolved gas, divided by edible oil volume, obtain the amount that unit edible oil under this pressure and temperature environment absorbs gas.
0 = P
This is vacuumized to reach the cylinder body of vapor liquid equilibrium, open large capacity stirrer and vacuum pump, while vacuumize, stir, gas in coil neutralization bottle is all extracted out, stop stirrer and vacuum pump, close rapidly nitrogen valve after being then filled with a certain amount of nitrogen, now P
0＇=101.96 KPa, T
0＇=6.210 L, the content of each component gas, N
2=0, ON cycle pump, single job before repeating, makes to reach secondary balancing, P
1＇=71.35 KPa, T
1＇=293K, the content of each component gas, N
2=0.By the equation of gas state, can calculate V
1＇ is saturated gas meltage S.
101.96×6.21/289 = 71.35 V
1＇= S = 8.997 （L）
The saturated inspiratory capacity of 5.01L oil is 8.997L, and every liter of oil absorbs 1.796 L nitrogen.
Actual gas flow=the S containing-V suction=8.997-0.015=8.982(L in 5.01L oil)
Embodiment of the present invention is only the description that the preferred embodiment of the present invention is carried out; not design of the present invention and scope are limited; do not departing under the prerequisite of design philosophy of the present invention; various modification and improvement that in this area, engineering technical personnel make technical scheme of the present invention; all should fall into protection scope of the present invention; the technology contents that the present invention asks for protection, is all documented in claims.