Dynamic regulation and control method for glass hue fluctuation of float production line

Abstract

The method solves the problems that when the glass hue has abnormal deviation, a traditional debugging method cannot quickly and accurately debug the glass hue and cannot quickly return the glass hue to a normal hue through a coloring agent. The invention discloses a hue prediction method suitable for glass composed of multiple raw materials, the formula and hue research and development period of high-transmittance glass is shortened to be within 1 h, the glass hue debugging regulation and control time is shortened to be 1-3 days from 12 days or above, and the hue regulation and control accuracy of a formula is verified through glass experimental data under multiple formulas, so that the hue prediction method is suitable for the glass composed of multiple raw materials. The glass hue is predicted in advance according to a glass formula through the four equations, and the errors between the glass hue and the actual test hue of a target product are as follows: T is within + / -0.07%, L is within + / -0.03, a * is within + / -0.01, and b * is within + / -0.01. The precision of predicted values of the hue prediction equations is high, so that the problem that when the float glass hue is debugged through an artificial experience attempt method, the hue cannot be debugged easily is solved. And the production efficiency is influenced due to long-term debugging and production halt of a glass production line.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic glass and relates to a dynamic regulation method for glass tone fluctuations in a float production line. Background Art

[0002] The present invention relates to an efficient method for adjusting the tone of glass in a float production line. There are many factors affecting the tone of glass in a float production line, such as glass thickness, the amount of various colorants, the air-gas ratio at each position, the amount of carbon powder, the amount of glauber's salt, and their ratios, etc., which are very complex. Engineers make qualitative adjustments based on experience or some viewpoints in papers, then observe the results, and then make the next round of adjustments, with low efficiency and difficult to guarantee quality.

[0003] Problems of the prior art: By adjusting the glass thickness, the amount of various colorants, the air-gas ratio at each position (volume ratio of combustion-supporting mixture gas to fuel gas), the amount of carbon powder, the amount of glauber's salt, and their ratios, etc. in multiple rounds, and it is not necessarily possible to achieve the goal. It is impossible to predict in advance the glass tone situation after adjusting the amount of colorant, and the efficiency of adjusting the glass tone in a float production line is low.

[0004] Generally, the thicker the glass thickness, the more coloring ions in the thickness direction of the glass, the lower the transmittance, and the deeper the tone. There are many factors affecting the glass thickness, such as the composition of the glass, the viscosity of the glass, the pulling rate of the glass, the forming parameters, etc. The types of colorants, different colorants have different absorption bands for visible light, resulting in different colors. The amount of colorant, generally, the larger the amount, the lower the transmittance of the glass and the deeper the tone. However, in the mixed colorants, there may be color complementarity between different colorants. Although used together, the transmittance may decrease, but the tone may become lighter. The air-gas ratio is an important influencing factor for variable-valence coloring ions, especially iron element. By adjusting the air-gas ratio, the atmosphere of the glass is changed, thereby affecting the valence state of the iron element, and thus changing the glass tone. The air-gas ratio can be regulated by manual operation. Glauber's salt is a commonly used fining agent in float glass production. Reasonable use can largely eliminate the bubble defects in the glass. However, the sulfur element in glauber's salt will also be affected by the atmosphere to generate S -2 , which will form FeS with the iron in the glass, making the glass produce a yellow tone. The remaining oxygen content or the flue gas atmosphere after combustion affects the valence state change of the coloring ions in the glass, thereby affecting the glass color.

[0005] For the glass produced by the float method, due to the incomplete uniform dispersion of the glass thickness, the amount of various colorants, the air-gas ratio at each position, the amount of carbon powder, the amount of glauber's salt, raw materials during the continuous production of the glass production line, or the influence of factors such as high-temperature aging of the equipment control circuit and environmental factors, the glass color gradually deviates from the normal constrained color range.

[0006] At present, when the glass tone on the production line is abnormal, it can only be manually debugged by the trial-and-error method, which not only wastes glass raw materials, but also has great blindness. It can only be judged and debugged by manual experience, and then the finished glass produced by debugging is subjected to tone inspection until the color of the target product glass meets the normal production constraints, and then production can be restarted. During this period, a large amount of glass raw materials are wasted, and the production line equipment needs to verify the debug test pieces, which seriously affects the mass production of normal production line glass.

[0007] Moreover, when unqualified products appear in the produced glass, it will also cause a large amount of waste of the raw materials for producing glass. There is an urgent need to develop a set of debugging equations to facilitate quickly predicting how to quickly adjust various influencing factors on the continuous production line after the glass color deviates, and correcting various influencing parameters to adjust the glass tone back to the normal qualified tone range. Avoid the problem of downtime verification and debugging. When normal production is carried out, only the tone of the already produced glass products can be tested passively, resulting in the production line being unable to be adjusted in time, and it is easy for a large number of glass products to have unqualified tones, resulting in glass scrapping, low production efficiency and yield, and waste of raw materials.

[0008] The theoretical basis of the formula of the present invention: "Handbook of Glass Properties and Technology" edited by Wang Chengyu and Tao Ying, Chemical Industry Press. Summary of the Invention

[0009] The present invention solves the problem that when the glass tone on the production line shows abnormal deviation, the traditional debugging method cannot quickly and accurately debug the glass tone, and the problem that the glass tone cannot be quickly returned to the normal tone through the colorant.

[0010] To solve the above problems, the present application is achieved through the following technical solutions: A dynamic regulation method for glass tone fluctuation in a float production line, comprising the following steps: S1. Substitute d, p, q, r, x, s, and α into the tone equation to obtain T, L, a*, and b*; S2. Judge whether T, L, a*, and b* in step S1 simultaneously satisfy the constraint conditions: 90.2% ≤ T ≤ 92.1%, 94.5 ≤ L ≤ 97.5, -0.1 ≤ a* ≤ 0.25, -0.26 ≤ b* ≤ 0.3; S2.1. If satisfied, dynamically regulate the glass tone in accordance with d, p, q, r, x, s, and α in step S1 and substitute them into steps S2.1.1 to S2.1.4 in sequence; S2.1.1. Substitute SiO 2 , Al 2 O 3 , MgO, K 2 O, Na 2 O, Li 2 O, ZrO2 , CaO, B 2 O 3 , Fe 2 O 3 Mix them evenly to obtain mixture A; S2.1.2. Add colorants Co 2 O 3 , Er 2 O 3 , Nd 2 O 3 to mixture A to obtain batch B; S2.1.3. Add Na 2 SO 4 to batch B and stir evenly to obtain mixture C; S2.1.4. Place mixture C in step S2.1.3 in a mixed gas of methane and nitrogen oxides and heat it to melt to obtain glass melt D. Stretch and form glass melt D to a thickness of d, anneal and cool it to room temperature to obtain a high transmittance glass with a regulated hue; S2.2. If not satisfied, substitute d + △d, p + △p, q + △q, r + △r, x + △x, s + △s, α + △α into the hue equation in step S1, and repeat steps S1~S2; wherein, d is the glass thickness, and p, q, r, x are the mass ratios of Co 2 O 3 , Er 2 O 3 , Nd 2 O 3 , NiO to the mass of mixture A respectively, s is the mass of Na 2 SO 4 contained in each kg of batch B.

[0011] The hue equation in step S1 includes four groups of equations of T, L, a*, and b*. Among them, T = (0.92104 - 0.00183×d + 0.00106×(1 - 1 / α) - 0.000001264×q - 0.000001438×r - 0.000077×p - 0.00002567×x - 0.0015×s)×100%; L = 96.86 - 0.07168×d + 0.436×(1 - 1 / α) - (0.45 / 10000)×q - (0.512 / 10000)×r - (52.8 / 10000)×p - (17.6 / 10000)×x - 1.5×s; a* = 0.02101 - 0.020391×d - 0.0003971×(1 - 1 / α) - (0.275 / 10000)×q - (0.312 / 10000)×r + (22.4 / 10000)×p - (4.48 / 10000)×x; b* = 0.1064 - 0.02429×d - 0.012×(1 - 1 / α) + (1.596 / 10000)×q + (1.814 / 10000)×r - (38.8 / 10000)×p + (12.933 / 10000)×x + 0.258×s / α; where α = 20.9% / (20.9% - O 2 remaining volume percentage), α = 1.3 to 20, s = 0.15 g to 1 g per kg of batch B, s is the added mass of Na 2 SO 4 in per kg of batch B; where T is the transmittance, L is the luminance, a* is the red - green chromaticity value, b* is the yellow - blue chromaticity; α is the excess nitrogen - oxygen mixture coefficient; all are dimensionless; at most two of p, q, r, x can be 0 simultaneously; The unit of the values of each parameter in the hue equation: the unit of d is mm; p, q, r, x are converted to ppm, the unit of s is g / kg of batch B, and the values in the above units are substituted into the hue equation for calculation.

[0012] In the mixture A in step S2.1.1, by mass, SiO 2 is 50% - 70%, Al 2 O 3 is 10% - 25%, MgO is 2% - 7%, K 2 O is 3% - 8%, Na 2 O is 10% - 18%, Li 2 O is 0 - 6%, ZrO 2 is 0 - 5%, CaO is 0 - 6%, B 2 O 3 is 0 - 10%, Fe 2 O 3 is 0.009% - 0.0115%.

[0013] The mixture A satisfies at least one of the following conditions: Li 2 O is 0.5% - 5.5%, ZrO 2 is 0.5% - 3%, CaO is 0.03% - 2%, B 2 O 3 is 0.3% - 3%.

[0014] In step S2.1.2, by mass ratio, mixture A: Co 2 O 3 : Er 2 O 3 : Nd 2 O 3 : NiO = mixture A: p: q: r: x = 1: 0 - 100 ppm: 0 - 300 ppm: 0 - 300 ppm: 0 - 300 ppm.

[0015] In step S2.1.3, by mass ratio, Na 2 SO 4 : batch B = 0.15 - 1: 1000.

[0016] In step S2.1.4, the melting temperature is 1600 °C - 1650 °C.

[0017] In step S2.1.4, by volume ratio, oxygen-nitrogen mixture: methane = 12.44 - 191.38: 1.

[0018] In step S2.1.4, the thickness d of the thickening of the high transmittance glass is 0.2 - 1.3 mm.

[0019] In step S2.2, Δd = 0 - 0.05, Δp = 0 - 1, Δq = 0 - 5, Δr = 0 - 3, Δx = 0 - 3, Δs = 0 - 0.02, Δα = 0 - 1.

[0020] 20.9% is the volume percentage of O in the initial oxygen-nitrogen mixture, and the remaining volume percentage is the volume percentage content of the remaining O 2 ; 2 The remaining volume percentage is the volume percentage content of the remaining oxygen; 2 The excess oxygen-nitrogen mixture coefficient α is the ratio of the actual amount of oxygen-nitrogen mixture required for methane combustion to the theoretical amount of oxygen-nitrogen mixture required, L (luminance): represents the light and dark degree of the color, ranging from 0 (black) to 100 (white). a* (red-green chromaticity): represents the shift of the color in the red and green directions, with positive values indicating red and negative values indicating green.

[0021] b* (yellow-blue chromaticity): represents the shift of the color in the yellow and blue directions, with positive values indicating yellow and negative values indicating blue.

[0022] Compared with the prior art, the beneficial effects of the present invention:

[0023] ​1. The present invention discloses a method for predicting the color tone of glass composed of multiple raw materials, shortening the formula and color tone research and development debugging cycle of the high transmittance glass in the present invention to within 1 hour. When producing finished glass with qualified color tone, the color tone debugging time for each piece of finished glass is shortened from more than 12 days to within 3 days. The present invention verifies the accuracy of formula-controlled color tone with glass experimental data under multiple formulas, as shown in Table 1 and Table 2. According to these four groups of equations, the glass color tone can be predicted in advance based on the glass formula, and the errors from the actual measured color tone of the target product are respectively: within ±0.07% for T, within ±0.03 for L, within ±0.01 for a*, and within ±0.01 for b*. The accuracy of the predicted values of the color tone prediction equation is very high, and the errors can be ignored, solving the problem that when the color tone of float glass is debugged by the manual experience trial method, the glass production line is in a debugging and shutdown state for a long time, affecting production efficiency.

[0024] 2. By adjusting the glass thickness d (d = 0.2 - 1.3 mm), the dosage p of Co 2 O 3 (p = 0 - 100 ppm), the dosage q of Er 2 O 3 (q = 0 - 300 ppm), the dosage r of Nd 2 O 3 (r = 0 - 300 ppm), the dosage x of NiO (x = 0 - 300 ppm), the dosage s of mirabilite (s = 0.15 - 1 g per kg of glass B), and the coefficient α of excess nitrogen-oxygen mixture during glass melting (α = 1.3 - 20), and then calculating in combination with four groups of equations, the color adjustment of float glass production line can be quickly carried out. Compared with the traditional multiple trial adjustments, it greatly improves the glass production efficiency and color tone accuracy. At the same time, it greatly shortens the glass R & D cycle, avoids wasting glass raw materials, saves glass production raw materials, and greatly improves the glass production efficiency. Specific Embodiments

[0025] Add raw materials to the raw materials according to the glass composition ratio of the present invention. After mixing them evenly in sequence, put them into the kiln furnace by a feeding machine. After being heated to a high temperature of 1600°C - 1650°C by the heat provided by methane combustion in the kiln furnace to melt into glass liquid, it is cooled in the working section, and finally the glass liquid flows into the tin bath and is formed under the action of a pulling machine, and then annealed and cooled in an annealing furnace to obtain the glass product of the present invention. 1 ppm (one part per million) in Table 1 and Table 2 of the present invention is 0.0001%.

[0026] Since the color of the glass is sensitive to the addition amount of the colorant, the glass color - matching formula is first brought into the equation to predict the values of T, L, a*, and b*; to avoid exceeding the constraint range: T is 90.2% - 92.1%, the brightness L is 94.5 - 97.5, the red - green chromaticity value a* is - 0.1 - 0.25, and the yellow - blue chromaticity value b* is - 0.26 - 0.3. If the constraint range is satisfied, then actual production is carried out. If it exceeds the constraint range, correction is performed through the equation Co 2 O 3 ,Er 2 O 3 ,Nd 2 O 3 ,The addition amount of NiO is until the constraint range is satisfied, and then the glass is prepared according to this formula. The measured values of T, L, a*, and b* of the obtained finished glass are compared.

[0027] In the formula, the coefficient α of the excess nitrogen - oxygen mixture is 1.3 - 20. α will affect the color of the glass. Because when the oxygen content is too high, Fe 2 O 3 melting will turn into light yellow Fe 3+ ,When the oxygen content is insufficient, Fe 3+ will be converted into light blue Fe 2+ ,It is necessary to continuously maintain the oxygen content in the atmosphere within a range that has less influence on Fe 2 O 3 to reduce the influence. The same is true for NiO.

[0028] The role of mirabilite (Na 2 SO 4 ): Mirabilite can be used as a fining agent for the glass melt, which can reduce the bubble defects in the glass. When the mirabilite content is too high, the S 2- in the glass will increase, forming sulfur chains or FeS, making the glass color turn yellow; at the same time, when the mirabilite content is too high, it is not good for the refractory bricks of the melting furnace and affects the life of the melting furnace. When the mirabilite content is too low, the fining effect of the glass melt is not good, resulting in too many bubble defects.

[0029] Fe 2 O 3 ,Co 2 O 3 ,Er 2 O 3 ,Nd 2 O 3 ,NiO are all glass color regulators: Fe 2 O 3 will make the glass show light yellow (Fe 3+ )or light blue (Fe 2+ ); Co 2 O 3will make the glass appear blue, Er 2 O 3 will make the glass appear magenta, NiO will make the glass appear grayish purple, Nd 2 O 3 can adjust the refractive index and transparency of the glass, thereby affecting the coloring of the glass. When the content of these four increases, the glass color will become darker and the transmittance will decrease.

[0030] Example 1 Prepare a glass mixture A1 with the following composition according to the above formula and steps: SiO 2 61.48%, Al 2 O 3 13%, MgO 5%, K 2 O 6%, Na 2 O 13%, Li 2 O 0.05%, ZrO 2 1%, CaO 0.05%, B 2 O 3 0.5%, Fe 2 O 3 0.01%.

[0031] Prepare glass raw materials with different thicknesses and different addition amounts of colorants respectively. The prepared glasses correspond to the 1st to 10th group of data in Table 1.

[0032] Example 2 Prepare a glass mixture A2 with the following composition according to the above formula and steps: SiO 2 55.89%, Al 2 O 3 17%, MgO 4%, K 2 O 3%, Na 2 O 13%, Li 2 O 5%, ZrO 2 1%, CaO 0.1%, B 2 O 3 1%, Fe 2 O 3 0.01%.

[0033] Prepare glass raw materials with different thicknesses and different addition amounts of colorants respectively. The prepared glasses correspond to the 11th to 20th group of data in Table 2.

[0034] Table 1

[0035] Table 2

[0036] Through the hue debugging method disclosed in the present invention, those skilled in the art can also adjust according to the constraint ranges of T, L, a*, and b*, and thus obtain different coloring formulas. The improvement of this method also falls within the protection scope of the present invention. Those skilled in the art can use the existing formula combined with the coefficient α of the excess nitrogen-oxygen mixture to inversely deduce the air-gas ratio of the fuel gas nitrogen-oxygen mixture to methane (the air-gas ratio is the volume usage ratio of the nitrogen-oxygen mixture to methane), which will not be elaborated in detail in the present invention. In the present invention, the molten glass fuel gas is methane, and the combustion-supporting gas is the nitrogen-oxygen mixture. In the nitrogen-oxygen mixture, the oxygen content is 20.9%. The initial temperatures and pressures of methane and the nitrogen-oxygen mixture are 25°C and 101.325 KPa. After determining the air-gas ratio of the nitrogen-oxygen mixture to methane, the volume flow rates of methane and the nitrogen-oxygen mixture entering the kiln and the exhaust gas flow rate of the exhaust gas are the same to maintain the constant oxygen content concentration in the kiln. The selection of methane and the nitrogen-oxygen mixture to melt glass in the present invention is only for convenience of explanation, rather than limiting that methane and the nitrogen-oxygen mixture must be used in the present invention.

Claims

1. A method for dynamically controlling the color tone fluctuation of float glass production line, characterized in that: The following steps are involved: S1. Substitute d, p, q, r, x, s, and α into the hue equation to obtain T, L, a*, and b*; S2. Determine whether T, L, a*, and b* in step S1 simultaneously satisfy the constraints: 90.2%≤T≤92.1%, 94.5≤L≤97.5, -0.1≤a*≤0.25, -0.26≤b*≤0.3; S2.

1. If satisfied, substitute d, p, q, r, x, s, and α in step S1 into steps S2.1.1 to S2.1.4 in sequence to dynamically control the glass tint; S2.1.

1. Evenly stir SiO2, Al2O3, MgO, K2O, Na2O, Li2O, ZrO2, CaO, B2O3 and Fe2O3 to obtain a mixture A; S2.1.2, adding colorants Co2O3, Er2O3, Nd2O3, NiO to mixed material A to obtain mixed material B; S2.1.3, add Na2SO4 to batch B and stir evenly to obtain mixture C; S2.1.4, placing the mixture C in step S2.1.3 in a mixture of methane and nitrogen and oxygen to heat and melt to obtain a glass liquid D, drawing the glass liquid D to a thickness of d, annealing and cooling to room temperature to obtain a high-transmittance glass with a well-controlled color tone; S2.2, if not satisfied, substitute d+△d, p+△p, q+△q, r+△r, x+△x, s+△s, α+△α into the hue equation in step S1, and repeat steps S1-S2; Where d is the glass thickness, p, q, r, and x are the mass ratios of Co2O3, Er2O3, Nd2O3, and NiO to the mass ratio of the mixed material A, respectively. s is the mass of Na2SO4 contained in each kg of batch B.

2. The method for dynamically controlling the color tone fluctuation of float glass production line according to claim 1, characterized in that: The hue equation in step S1 includes four sets of equations: T, L, a* and b*, where: T=(0.92104-0.00183×d+0.00106×(1-1 / α)-0.000001264×q-0.000001438×r-0.000077×p-0.00002567×x-0.0015×s)×100%; L=96.86-0.07168×d+0.436×(1-1 / α)-(0.45 / 10000)×q-(0.512 / 10000)×r-(52.8 / 10000)×p-(17.6 / 10000)×x-1.5×s; a*=0.02101-0.020391×d-0.0003971×(1-1 / α)-(0.275 / 10000)×q-(0.312 / 10000)×r+(22.4 / 10000)×p-(4.48 / 10000)×x; b*=0.1064-0.02429×d-0.012×(1-1 / α)+(1.596 / 10000)×q+(1.814 / 10000)×r-(38.8 / 10000)×p+(12.933 / 10000)×x+0.258×s / α; Among them, α=20.9% / (20.9%-O2 residual volume percentage), α=1.3~20, s = 0.15 g ~ 1 g / kg batch B, s is the added mass of Na2SO4 per kg batch B; Wherein, T is transmittance, L is brightness, a* is red-green value, b* is yellow-blue value; α is excess nitrogen-oxygen mixture coefficient; all are dimensionless; At most two of p, q, r, and x are 0 at the same time; The units of the parameters in the color tone equation are: d is in mm; p, q, r, x are converted to ppm, and s is in g / kg of compound B. Substitute the values ​​in the above units into the color tone equation for calculation.

3. The method for dynamically controlling the color tone fluctuation of float glass production line according to claim 1, characterized in that: In the mixed material A of step S2.1.1, by mass, SiO2 is 50%~70%, Al2O3 is 10%~25%, MgO is 2%~7%, K2O is 3%~8%, Na2O is 10%~18%, Li2O is 0~6%, ZrO2 is 0~5%, CaO is 0~6%, B2O3 is 0~10%, and Fe2O3 is 0.009%~0.0115%.

4. The method for dynamically controlling the color tone fluctuation of float glass production line according to claim 3, characterized in that: The mixed material A satisfies at least one of the following conditions: Li2O is 0.5%~5.5%, ZrO2 is 0.5%~3%, CaO is 0.03%~2%, and B2O3 is 0.3%~3%.

5. The method for dynamically controlling the color tone fluctuation of float glass production line according to claim 1, characterized in that: In the step S2.1.2, the mass ratio is: mixture A: Co2O3: Er2O3: Nd2O3: NiO = mixture A: p: q: r: x = 1: 0~100ppm: 0~300ppm: 0~300ppm: 0~300ppm.

6. The method for dynamically controlling the color tone fluctuation of float glass production line according to claim 1, characterized in that: In step S2.1.3, the mass ratio of Na2SO4: batch material B is 0.15~1:1000.

7. The method for dynamically controlling the color tone fluctuation of float glass production line according to claim 1, characterized in that: The melting temperature in step S2.1.4 is 1600°C to 1650°C.

8. The method for dynamically controlling the color tone fluctuation of float glass production line according to claim 1, characterized in that: In step S2.1.4, the volume ratio of oxygen-nitrogen mixed gas to methane is 12.44-191.38:

1.

9. The method for dynamically controlling the color tone fluctuation of float glass production line according to claim 1, characterized in that: The thickness d of the high transmittance glass drawn in step S2.1.4 is 0.2-1.3 mm.

10. The method for dynamically controlling the color tone fluctuation of float glass production line according to claim 1, characterized in that: In the step S2.2, △d=0~0.05, △p=0~1, △q=0~5, △r=0~3, △x=0~3, △s=0~0.02, and △α=0~1.

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