Before kiln, the characteristic that should burn base glair according to place decides a graph that warm up and drops in temperature. Distributinging circumstance of the curve and following element are having close relationship:
1, the composition of preform and purity;
2, the water content; when base substrate enters pit
3, the ply of base substrate and size, the temperature of base substrate conducts coefficient;
4, the type of kiln, construction and capacity, and; of density of loading of kiln
5, of photograph of high temperature crystallization create the character that reachs base with change. The kiln of size waits in, of fire white porcelain warm up speed is about inside following limits: Dehydration period- - warm up hourly 20-40 ℃ , burn all the time; oxidizes till 500 ℃ period- - warm up hourly 50-70 ℃ , come from 500 ℃ till 900 ℃ are controlled, ; Bo is changed period- - warm up hourly 25-35 ℃ , arrive from 900 ℃ till 1350 ℃ left and right sides; heat preservation period- - warm up about hourly 5 ℃ are controlled to 15 ℃ . Our country china is controlled in 1320 ℃ commonly firing, but the kiln fire temperature that has plant of some of porcelain yield a division at present has actually to high temperature firing the tendency that temperature develops, if Hunan has some of big porcelain plant,already amounted to 1410 ℃ . Fluctuant and following element, can control the temperature of kiln:
1, ventilated lose by force- - ventilated strong, warm up fast. Control is ventilated lose by force usable adjustment flashboard, change furnace bar space, the method such as artificial blast undertakes;
2, the temperature of the fluctuant gas that enter pit- - temperature of the gas that enter pit is high, be helpful for burn and warming up, use warm-up airy method to be able to increase the calorific value of kiln gas, carry high fever to become temperature thereby.
3, in preventing cold air to invade kiln- - cold air invades kiln in, meeting slow down warms up speed. Enter pit to prevent air conditioning, should seal close kiln wall, master go grey time and frequency.
4, coal also should notice to control every time coal quantity, the bulk that controls coal piece (the air much) with coal small piece, dominate the time of coal, and the method that masters coal.