Low temperature firing method of mixed loading porcelain body

Abstract

The application discloses a low-temperature firing method of mixed porcelain blanks, which comprises three stages. By controlling the kiln pressure, combustion-supporting wind, temperature-adjusting wind, natural gas flow and opening degree of each zone in each stage, the heating speed of each stage is controlled, the porcelain blanks prepared by dry and wet methods are fired together, the problem that the two kinds of porcelain blanks need to be fired respectively in the prior art is solved, the problem of main body cracking and burst of the porcelain blanks due to different water contents of the two kinds of porcelain blanks in the firing process is solved, and the firing efficiency is greatly improved under the premise of ensuring the quality of the porcelain blanks.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric porcelain product production, and particularly relates to a low-temperature firing method of mixed loading porcelain body. BACKGROUND

[0002] In the electric porcelain industry, the process of the porcelain body prepared by the dry method is as follows: the porcelain body powder is obtained by spray granulation, the water content of the powder is kept within a certain process range, the powder is formed into a porcelain body after being pressed, trimmed and dried, and the porcelain body prepared by the dry method still contains (0.6-0.8)% water.

[0003] Therefore, in the low-temperature stage of the firing of the porcelain body in the kiln, the mechanical combined water and the adsorbed water on the surface are mainly discharged, and in the firing process, the water content is uniformly discharged and the temperature rising speed is controlled to avoid the formation of a large steam pressure in the porcelain body due to the too fast temperature rising, which leads to the cracking or explosion of the porcelain body.

[0004] At present, the porcelain bodies prepared by the dry method and the wet method are fired in the same kiln, and the water content of the wet porcelain body is higher than that of the dry porcelain body, so that the water content of the wet porcelain body is volatilized when heated, which leads to the cracking or explosion of the dry porcelain body. Therefore, in order to ensure the firing quality of various types of porcelain bodies, the porcelain bodies need to be fired separately, which leads to a low production efficiency. SUMMARY

[0005] The present application aims to provide a low-temperature firing method of mixed loading porcelain body to overcome the technical problems in the prior art that the porcelain bodies prepared by the dry method and the wet method need to be fired separately and the porcelain body is easily cracked or exploded during the mixed loading firing of the two types of porcelain bodies.

[0006] To solve the above problems, the present application adopts the following technical scheme.

[0007] A low-temperature firing method of mixed loading porcelain body includes three stages: the first stage is 50 DEG C and below, the combustion-supporting air flow, the temperature-adjusting air flow, the natural gas flow, the pressure in the kiln and the opening degree of the branch pipe of the ignition valve in each zone of the kiln are controlled, so that when the actual temperature and the temperature of the intermediate main control point differ by (5-8) DEG C, the kiln is in a relative zero pressure state, and the temperature rising speed is (8-10) DEG C / h;

[0008] The second stage is (51-95) DEG C, the combustion-supporting air flow, the temperature-adjusting air flow, the natural gas flow, the pressure in the kiln and the opening degree of the branch pipe of the ignition valve in each zone of the kiln are controlled, so that when the actual temperature and the temperature of the intermediate main control point differ by (3-5) DEG C, the kiln is in a negative pressure state, and the temperature rising speed is (10-12) DEG C / h;

[0009] The third stage, (96-150) °C, the kiln each area combustion-supporting air flow, temperature-adjusting air volume, natural gas flow, kiln pressure and each area ignition valve branch opening degree are controlled, so that when the actual temperature and the intermediate main control point temperature difference is (2-3) °C, the kiln is in negative pressure state, the temperature rising speed is (12-15) °C / h.

[0010] Further, the first stage kiln each area combustion-supporting air flow range is (360-420) m 3 / h, the temperature-adjusting air volume range is (320-360) m 3 / h, the natural gas flow range is (0.5-1.5) m 3 / h, the kiln pressure range is (-0.2-+0.2) Pa; each area ignition valve branch opening degree is adjusted to (0-1.0) %.

[0011] Further, the second stage kiln each area combustion-supporting air flow range is (310-350) m 3 / h, the temperature-adjusting air volume range is (290-320) m 3 / h, the natural gas flow range is (1.0-1.5) m 3 / h, the kiln pressure range is (-4--2) Pa; each area ignition valve branch opening degree is adjusted to (1.0-2.0) %.

[0012] Further, the third stage kiln each area combustion-supporting air flow range is (280-300) m 3 / h, the temperature-adjusting air volume range is (260-280) m 3 / h, the natural gas flow range is (1.5-2.5) m 3 / h, the kiln pressure range is (-2--1) Pa; each area ignition valve branch opening degree is adjusted to (2.0-3.0) %.

[0013] Further, in the first stage firing process, the frequency conversion range of the exhaust fan is controlled to be (9-11) Hz, and the ratio of air to fuel gas is (260-275):1.

[0014] Further, in the second stage firing process, the frequency conversion range of the exhaust fan is controlled to be (20-25) Hz.

[0015] Further, in the third stage firing process, the frequency conversion range of the exhaust fan is controlled to be (25-30) Hz.

[0016] Further, in the second stage firing process, the ratio of air to fuel gas is (210-230):1.

[0017] Further, in the third stage firing process, the ratio of air to fuel gas is (150-180):1.

[0018] Further, the kiln is divided into zones, and in each stage of the firing process, the combustion air flow, temperature adjusting air flow, natural gas flow and ignition valve branch opening are adjusted according to the different positions of the porcelain body in the kiln.

[0019] Compared with the prior art, the present application has the following beneficial technical effects:

[0020] The present application relates to a low-temperature firing method for mixed porcelain bodies, which uniformly fires the porcelain bodies prepared by dry and wet methods, controls the flow of combustion air, temperature adjusting air, natural gas and the opening of each zone, and further controls the heating rate in each stage, so that the porcelain bodies prepared by dry and wet methods are fired together, solving the problem of separate firing of the two types of porcelain bodies in the prior art; and solving the problem of body cracking and bursting of the porcelain body due to the different water contents of the two types of porcelain bodies during the firing process; the present application uniformly fires the two types of porcelain bodies, greatly improving the firing efficiency under the premise of ensuring the quality of the porcelain body. DETAILED DESCRIPTION

[0021] The present application provides a low-temperature firing method for mixed porcelain bodies, which mainly includes three stages:

[0022] In the first stage, the combustion air flow of each zone of the kiln is controlled at (360-420) m 3 / h, the temperature adjusting air flow is controlled at (320-360) m 3 / h, the natural gas flow is controlled at (0.5-1.5) m 3 / h, the pressure in the kiln is controlled at (-0.2-+0.2) Pa, the opening of the ignition valve branch of each zone is adjusted to (0-1.0) %, so that when the actual temperature and the intermediate main control point temperature differ by (5-8) °C, the kiln is in a relative zero pressure state at this time, and this operation is the basis for realizing quality control in the second stage, and the heating rate in this stage is (8-10) °C / h.

[0023] In addition, during the firing process, the frequency of the exhaust fan is controlled at (9-11) Hz, and the ratio of air to fuel gas is (260-275):1, so that the temperature difference between the inside and outside of the porcelain body is reduced to within 10°C.

[0024] In the second stage, the combustion air flow of each zone of the kiln is controlled at (310-350) m 3 / h, the temperature adjusting air flow is controlled at (290-320) m 3 / h, the natural gas flow is controlled at (1.0-1.5) m 3 / h, the opening degree of the branch pipe of the ignition valve of each zone is adjusted to (1.0-2.0)%, so that when the actual temperature of the firing point differs from the temperature of the intermediate main control point by (3-5)℃, the kiln is in a negative pressure state at this time, the temperature rising speed of this stage is (10-12)℃ / h, the residual moisture contained in the porcelain body of the porcelain body entering the kiln is (0.6-0.8)% for dry porcelain body and (1.2-2.0)% for wet porcelain body, and this operation realizes the uniform discharge of the mechanical combined water and the adsorbed water on the surface of the porcelain body, so that the porcelain body explosion in the next stage can be avoided.

[0025] During the firing process, the frequency of the exhaust fan is controlled to be (20-25)Hz, and the ratio of air to fuel gas is (210-230):1.

[0026] The third stage is (96-150)℃, the combustion-supporting air flow of each zone of the kiln is controlled to be (280-300)m 3 / h, the temperature-adjusting air flow is controlled to be (260-280)m 3 / h, the natural gas flow is controlled to be (1.5-2.5)m 3 / h, the pressure in the kiln is controlled to be (-2--1)Pa, the opening degree of the branch pipe of the ignition valve of each zone is adjusted to (2.0-3.0)%, so that when the actual temperature of the firing point differs from the temperature of the intermediate main control point by (2-3)℃, the kiln is in a negative pressure state at this time, the temperature rising speed of this stage is (12-15)℃ / h, and this operation realizes the uniform discharge of the mechanical combined water and the adsorbed water on the surface of the porcelain body.

[0027] During the firing process, the frequency of the exhaust fan is controlled to be (25-30)Hz, and the ratio of air to fuel gas is (150-180):1.

[0028] The kiln is divided into seven zones, each zone has three burners, each zone has three control points, and the seven zones are uniformly distributed; wherein, the middle part of each zone is the main control point, and the upper and lower parts are the auxiliary control points.

[0029] The first zone is close to the kiln door, the seventh zone is close to the rear wall of the kiln, the sealing property is relatively weak, and the temperature is relatively high compared with other regions, so it is required that the combustion-supporting air flow of this zone is relatively small, that is, the air-fuel ratio is small, and the temperature-adjusting air flow is relatively high, so that the temperature of this region can be prevented from rising too fast, and the specific control is as follows:

[0030] Example 1

[0031] The first stage is 50℃ and below, the combustion-supporting air flow of each zone of the kiln is controlled to be (360-390)m 3 / h, the temperature-adjusting air flow is controlled to be (320-340)m 3 / h, the natural gas flow is controlled to be (0.5-1)m 3 / h, the air-fuel ratio is 260:1. When the actual temperature of the firing point differs from the temperature of the intermediate main control point by (5-8) °C, the kiln is in a relative zero pressure state at this time, and this operation is the basis for realizing quality control in the second stage, and the temperature rising speed in this stage is (8-10) °C / h.

[0032] Zone 1: the combustion air flow is controlled at 360 m 3 / h, the temperature adjusting air flow is controlled at 320 m 3 / h, the natural gas flow is controlled at 0.5 m 3 / h, the kiln pressure is -0.2 Pa, the firing valve branch opening is adjusted to 0%, the frequency of the exhaust fan is 9 Hz, and the air-fuel ratio is 260:1. When the actual temperature of the firing point differs from the temperature of the intermediate main control point by 8 °C, the kiln is in a relative zero pressure state at this time, and the temperature rising speed in this stage is 10 °C / h.

[0033] Zone 4: the combustion air flow is controlled at 375 m 3 / h, the temperature adjusting air flow is controlled at 330 m 3 / h, the natural gas flow is controlled at 0.8 m 3 / h, the kiln pressure is -0.2 Pa, the firing valve branch opening is adjusted to 0%, the frequency of the exhaust fan is 9 Hz, and the air-fuel ratio is 260:1. When the actual temperature of the firing point differs from the temperature of the intermediate main control point by 6 °C, the kiln is in a relative zero pressure state at this time, and the temperature rising speed in this stage is 9 °C / h.

[0034] Zone 7: the combustion air flow is controlled at 390 m 3 / h, the temperature adjusting air flow is controlled at 340 m 3 / h, the natural gas flow is controlled at 1 m 3 / h, the kiln pressure is -0.2 Pa, the firing valve branch opening is adjusted to 0%, the frequency of the exhaust fan is 9 Hz, and the air-fuel ratio is 260:1. When the actual temperature of the firing point differs from the temperature of the intermediate main control point by 7 °C, the kiln is in a relative zero pressure state at this time, and the temperature rising speed in this stage is 10 °C / h.

[0035] The other zones are adjusted according to the ranges mentioned above.

[0036] The second stage, (51-95) °C, the combustion air flow of each zone of the kiln is controlled at (310-330) m 3 / h, the temperature adjusting air flow is controlled at (290-305) m 3 / h, the natural gas flow is controlled at (1.0-1.3) m 3h, the firing valve branch opening degree is adjusted to 1%, the kiln pressure is controlled at -4 Pa, the exhaust fan frequency is changed to 20 Hz, the air and gas ratio is 210:1, when the actual temperature of the firing point and the temperature of the intermediate main control point differ by 3-5°C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 10-12°C / h.

[0037] Zone 1: the combustion air flow is controlled at 310 m 3 / h, the temperature adjusting air flow is controlled at 290 m 3 / h, the natural gas flow is controlled at 1 m 3 / h, the firing valve branch opening degree is adjusted to 1%, the kiln pressure is controlled at -4 Pa, the exhaust fan frequency is changed to 20 Hz, the air and gas ratio is 210:1, when the actual temperature of the firing point and the temperature of the intermediate main control point differ by 5°C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 12°C / h.

[0038] Zone 4: the combustion air flow is controlled at 320 m 3 / h, the temperature adjusting air flow is controlled at 297 m 3 / h, the natural gas flow is controlled at 1.2 m 3 / h, the firing valve branch opening degree is adjusted to 1%, the kiln pressure is controlled at -4 Pa, the exhaust fan frequency is changed to 20 Hz, the air and gas ratio is 210:1, when the actual temperature of the firing point and the temperature of the intermediate main control point differ by 3°C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 10°C / h.

[0039] Zone 7: the combustion air flow is controlled at 330 m 3 / h, the temperature adjusting air flow is controlled at 305 m 3 / h, the natural gas flow is controlled at 1.3 m 3 / h, the firing valve branch opening degree is adjusted to 1%, the kiln pressure is controlled at -4 Pa, the exhaust fan frequency is changed to 20 Hz, the air and gas ratio is 210:1, when the actual temperature of the firing point and the temperature of the intermediate main control point differ by 4°C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 11°C / h.

[0040] The other zones are adjusted according to the ranges mentioned above.

[0041] The third stage, (96-150) °C, the combustion air flow of each zone of the kiln is controlled at (280-290) m 3 / h, the temperature adjusting air flow is controlled at (260-270) m 3 / h, the natural gas flow is controlled at (1.5-2.0) m 3h, the firing valve branch pipe opening degree of each zone is adjusted to 2%, the frequency of the exhaust fan is 25 Hz, the air and gas ratio is 150:1, when the actual temperature of the firing point and the temperature of the intermediate main control point differ by (2-3) °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is (12-15) °C / h.

[0042] Zone 1: the combustion-supporting air flow is controlled at 280 m 3 / h, the temperature-adjusting air flow is controlled at 260 m 3 / h, the natural gas flow is controlled at 1.5 m 3 / h, the kiln pressure is controlled at -2 Pa, the firing valve branch pipe opening degree of each zone is adjusted to 2%, the frequency of the exhaust fan is 25 Hz, the air and gas ratio is 150:1, when the actual temperature of the firing point and the temperature of the intermediate main control point differ by 3 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 15 °C / h.

[0043] Zone 4: the combustion-supporting air flow is controlled at 285 m 3 / h, the temperature-adjusting air flow is controlled at 265 m 3 / h, the natural gas flow is controlled at 1.8 m 3 / h, the kiln pressure is controlled at -2 Pa, the firing valve branch pipe opening degree of each zone is adjusted to 2%, the frequency of the exhaust fan is 25 Hz, the air and gas ratio is 150:1, when the actual temperature of the firing point and the temperature of the intermediate main control point differ by 2 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 12 °C / h.

[0044] Zone 7: the combustion-supporting air flow is controlled at 290 m 3 / h, the temperature-adjusting air flow is controlled at 270 m 3 / h, the natural gas flow is controlled at 2 m 3 / h, the kiln pressure is controlled at -2 Pa, the firing valve branch pipe opening degree of each zone is adjusted to 2%, the frequency of the exhaust fan is 25 Hz, the air and gas ratio is 150:1, when the actual temperature of the firing point and the temperature of the intermediate main control point differ by 3 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 14 °C / h.

[0045] The other zones are adjusted according to the above-mentioned ranges.

[0046] From the inspection of the porcelain pieces, the qualified rate of the dry-process porcelain pieces is stably (97-98) %, and the qualified rate of the wet-process porcelain pieces is stably (97.5-98.5) %, which meets the expected effect.

[0047] Example 2

[0048] In the first stage, 50 °C and below, the combustion-supporting air flow of each zone of the kiln is controlled at (360-390) m 3 / h, the temperature-adjusting air flow is controlled at (320-340) m3 / h, the kiln pressure is controlled at 0 Pa, the branch opening of the ignition valve of each zone is adjusted to 0.5%, the frequency of the exhaust fan is 10 Hz, the ratio of air to gas is 270:1, when the actual temperature of the point and the temperature of the intermediate main control point differ by (5-8) °C, the kiln is in a relative zero pressure state at this time, and the temperature rising speed of this stage is (8-10) °C / h. 3 / h, the kiln pressure is controlled at 0 Pa, the branch opening of the ignition valve of each zone is adjusted to 0.5%, the frequency of the exhaust fan is 10 Hz, the ratio of air to gas is 270:1, when the actual temperature of the point and the temperature of the intermediate main control point differ by (5-8) °C, the kiln is in a relative zero pressure state at this time, and the temperature rising speed of this stage is (8-10) °C / h.

[0049] Zone 1: the combustion air flow is controlled at 360 m 3 / h, the temperature adjusting air flow is controlled at 320 m 3 / h, the natural gas flow is controlled at 0.5 m 3 / h, the kiln pressure is controlled at 0 Pa, the branch opening of the ignition valve of each zone is adjusted to 0.5%, the frequency of the exhaust fan is 10 Hz, the ratio of air to gas is 270:1, when the actual temperature of the point and the temperature of the intermediate main control point differ by 6 °C, the kiln is in a relative zero pressure state at this time, and the temperature rising speed of this stage is 9 °C / h.

[0050] Zone 4: the combustion air flow is controlled at 375 m 3 / h, the temperature adjusting air flow is controlled at 330 m 3 / h, the natural gas flow is controlled at 0.8 m 3 / h, the kiln pressure is controlled at 0 Pa, the branch opening of the ignition valve of each zone is adjusted to 0.5%, the frequency of the exhaust fan is 10 Hz, the ratio of air to gas is 270:1, when the actual temperature of the point and the temperature of the intermediate main control point differ by 6 °C, the kiln is in a relative zero pressure state at this time, and the temperature rising speed of this stage is 8 °C / h.

[0051] Zone 7: the combustion air flow is controlled at 390 m 3 / h, the temperature adjusting air flow is controlled at 340 m 3 / h, the natural gas flow is controlled at 1 m 3 / h, the kiln pressure is controlled at 0 Pa, the branch opening of the ignition valve of each zone is adjusted to 0.5%, the frequency of the exhaust fan is 10 Hz, the ratio of air to gas is 270:1, when the actual temperature of the point and the temperature of the intermediate main control point differ by 8 °C, the kiln is in a relative zero pressure state at this time, and the temperature rising speed of this stage is 10 °C / h.

[0052] The other zones are adjusted according to the range mentioned above.

[0053] The second stage is (51-95) °C, the combustion air flow of each zone of the kiln is controlled at (310-330) m 3 / h, the temperature adjusting air flow is controlled at (290-305) m 3 / h, the natural gas flow is controlled at (1.0-1.3) m 3 / h, the air-fuel ratio is 220:1, when the actual temperature of the firing point is different from the temperature of the main control point by (3-5) °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is (10-12) °C / h.

[0054] Zone 1: the combustion air flow is controlled at 310 m 3 / h, the temperature adjusting air flow is controlled at 290 m 3 / h, the natural gas flow is controlled at 1 m 3 / h, the firing valve branch opening is adjusted to 1%, the kiln pressure is controlled at -3 Pa, the firing valve branch opening of each zone is adjusted to 1.5%, the frequency of the exhaust fan is 23 Hz, the air-fuel ratio is 220:1, when the actual temperature of the firing point is different from the temperature of the main control point by 4 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 10 °C / h.

[0055] Zone 4: the combustion air flow is controlled at 320 m 3 / h, the temperature adjusting air flow is controlled at 297 m 3 / h, the natural gas flow is controlled at 1.2 m 3 / h, the kiln pressure is controlled at -3 Pa, the firing valve branch opening of each zone is adjusted to 1.5%, the frequency of the exhaust fan is 23 Hz, the air-fuel ratio is 220:1, when the actual temperature of the firing point is different from the temperature of the main control point by 3 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 10 °C / h.

[0056] Zone 7: the combustion air flow is controlled at 330 m 3 / h, the temperature adjusting air flow is controlled at 305 m 3 / h, the natural gas flow is controlled at 1.3 m 3 / h, the firing valve branch opening is adjusted to 1%, the kiln pressure is controlled at -3 Pa, the firing valve branch opening of each zone is adjusted to 1.5%, the frequency of the exhaust fan is 23 Hz, the air-fuel ratio is 220:1, when the actual temperature of the firing point is different from the temperature of the main control point by 5 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 11 °C / h.

[0057] The other zones are adjusted according to the ranges mentioned above.

[0058] The third stage, (96-150) °C, the combustion air flow of each zone of the kiln is controlled at (280-290) m 3 / h, the temperature adjusting air flow is controlled at (260-270) m 3 / h, the natural gas flow is controlled at (1.5-2.0) m 3 / h, the air-fuel ratio is 165:1, when the actual temperature of the firing point and the temperature of the intermediate main control point differ by 2-3°C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 12-15°C / h.

[0059] Zone 1 : the combustion-supporting air flow is controlled at 280 m 3 / h, the temperature-adjusting air flow is controlled at 260 m 3 / h, the natural gas flow is controlled at 1.5 m 3 / h, the kiln pressure is controlled at -1.5 Pa, the branch opening of the firing valve of each zone is adjusted to 2.5%, the frequency of the exhaust fan is 28 Hz, the air-fuel ratio is 165:1, when the actual temperature of the firing point and the temperature of the intermediate main control point differ by 3°C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 14°C / h.

[0060] Zone 4: the combustion-supporting air flow is controlled at 285 m 3 / h, the temperature-adjusting air flow is controlled at 265 m 3 / h, the natural gas flow is controlled at 1.8 m 3 / h, the kiln pressure is controlled at -1.5 Pa, the branch opening of the firing valve of each zone is adjusted to 2.5%, the frequency of the exhaust fan is 28 Hz, the air-fuel ratio is 165:1, when the actual temperature of the firing point and the temperature of the intermediate main control point differ by 2°C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 12°C / h.

[0061] Zone 7: the combustion-supporting air flow is controlled at 290 m 3 / h, the temperature-adjusting air flow is controlled at 270 m 3 / h, the natural gas flow is controlled at 2 m 3 / h, the kiln pressure is controlled at -1.5 Pa, the branch opening of the firing valve of each zone is adjusted to 2.5%, the frequency of the exhaust fan is 28 Hz, the air-fuel ratio is 165:1, when the actual temperature of the firing point and the temperature of the intermediate main control point differ by 3°C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 12°C / h.

[0062] The other zones are adjusted according to the above-mentioned ranges.

[0063] From the inspection of the porcelain pieces, the qualified rate of the dry-process porcelain pieces is stably (97.5-98.5)%, and the qualified rate of the wet-process porcelain pieces is stably (97.5-98.5)%, which meets the expected effect.

[0064] Example 3

[0065] In the first stage, the combustion-supporting air flow of each zone of the kiln is controlled at (360-390) m 3 / h, the temperature control of the air is 320-340 m 3 / h, the gas flow is controlled at 0.5-1 m 3 / h, the pressure in the kiln is controlled at 0.2 Pa, the branch opening of the ignition valve of each zone is adjusted to 1%, the frequency of the exhaust fan is 11 Hz, the ratio of air to gas is 275:1, when the actual temperature of the point is different from the temperature of the main control point by 5-8 °C, the kiln is in a relative zero pressure state at this time, and the heating speed of this stage is 8-10 °C / h.

[0066] Zone 1: the combustion air flow is controlled at 360 m 3 / h, the temperature control of the air is 320 m 3 / h, the gas flow is controlled at 0.5 m 3 / h, the pressure in the kiln is controlled at 0.2 Pa, the branch opening of the ignition valve of each zone is adjusted to 1%, the frequency of the exhaust fan is 11 Hz, the ratio of air to gas is 275:1, when the actual temperature of the point is different from the temperature of the main control point by 6 °C, the kiln is in a relative zero pressure state at this time, and the heating speed of this stage is 9 °C / h.

[0067] Zone 4: the combustion air flow is controlled at 375 m 3 / h, the temperature control of the air is 330 m 3 / h, the gas flow is controlled at 0.8 m 3 / h, the pressure in the kiln is controlled at 0.2 Pa, the branch opening of the ignition valve of each zone is adjusted to 1%, the frequency of the exhaust fan is 11 Hz, the ratio of air to gas is 275:1, when the actual temperature of the point is different from the temperature of the main control point by 6 °C, the kiln is in a relative zero pressure state at this time, and the heating speed of this stage is 8 °C / h.

[0068] Zone 7: the combustion air flow is controlled at 390 m 3 / h, the temperature control of the air is 340 m 3 / h, the gas flow is controlled at 1 m 3 / h, the pressure in the kiln is controlled at 0.2 Pa, the branch opening of the ignition valve of each zone is adjusted to 1%, the frequency of the exhaust fan is 11 Hz, the ratio of air to gas is 275:1, when the actual temperature of the point is different from the temperature of the main control point by 8 °C, the kiln is in a relative zero pressure state at this time, and the heating speed of this stage is 10 °C / h.

[0069] The other zones are adjusted according to the ranges mentioned above.

[0070] The second stage is (51-95) °C, the combustion air flow of each zone of the kiln is controlled at (310-330) m 3 / h, the temperature control of the air is (290-305) m 3 / h, the kiln pressure is controlled at -2 Pa, the branch opening of the ignition valve of each zone is adjusted to 2%, the frequency of the exhaust fan is 25 Hz, the ratio of air to gas is 230:1, when the actual temperature of the point differs from the temperature of the intermediate main control point by (3-5) °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is (10-12) °C / h. 3 / h, the kiln pressure is controlled at -2 Pa, the branch opening of the ignition valve of each zone is adjusted to 2%, the frequency of the exhaust fan is 25 Hz, the ratio of air to gas is 230:1, when the actual temperature of the point differs from the temperature of the intermediate main control point by (3-5) °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is (10-12) °C / h.

[0071] Zone 1: the combustion air flow is controlled at 310 m 3 / h, the temperature adjusting air flow is controlled at 290 m 3 / h, the natural gas flow is controlled at 1 m 3 / h, the kiln pressure is controlled at -2 Pa, the branch opening of the ignition valve of each zone is adjusted to 2%, the frequency of the exhaust fan is 25 Hz, the ratio of air to gas is 230:1, when the actual temperature of the point differs from the temperature of the intermediate main control point by 5 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 12 °C / h.

[0072] Zone 4: the combustion air flow is controlled at 320 m 3 / h, the temperature adjusting air flow is controlled at 297 m 3 / h, the natural gas flow is controlled at 1.2 m 3 / h, the kiln pressure is controlled at -2 Pa, the branch opening of the ignition valve of each zone is adjusted to 2%, the frequency of the exhaust fan is 25 Hz, the ratio of air to gas is 230:1, when the actual temperature of the point differs from the temperature of the intermediate main control point by 3 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 10 °C / h.

[0073] Zone 7: the combustion air flow is controlled at 330 m 3 / h, the temperature adjusting air flow is controlled at 305 m 3 / h, the natural gas flow is controlled at 1.3 m 3 / h, the kiln pressure is controlled at -2 Pa, the branch opening of the ignition valve of each zone is adjusted to 2%, the frequency of the exhaust fan is 25 Hz, the ratio of air to gas is 230:1, when the actual temperature of the point differs from the temperature of the intermediate main control point by 4 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 11 °C / h.

[0074] The other zones are adjusted according to the ranges mentioned above.

[0075] The third stage, (96-150) °C, the combustion air flow of each zone of the kiln is controlled at (280-290) m 3 / h, the temperature adjusting air flow is controlled at (260-270) m 3 / h, the natural gas flow is controlled at (1.5-2.0) m 3 / h, the opening degree of the branch pipe of the ignition valve of each zone is adjusted to 3%, the frequency of the exhaust fan is 30 Hz, the ratio of air to gas is 180:1, when the actual temperature of the point differs from the temperature of the main control point by (2-3) °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is (12-15) °C / h.

[0076] Zone 1: the combustion-supporting air flow is controlled at 280 m 3 / h, the temperature-adjusting air flow is controlled at 260 m 3 / h, the natural gas flow is controlled at 1.5 m 3 / h, the kiln pressure is controlled at -1 Pa, the opening degree of the branch pipe of the ignition valve of each zone is adjusted to 3%, the frequency of the exhaust fan is 30 Hz, the ratio of air to gas is 180:1, when the actual temperature of the point differs from the temperature of the main control point by 3 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 15 °C / h.

[0077] Zone 4: the combustion-supporting air flow is controlled at 285 m 3 / h, the temperature-adjusting air flow is controlled at 265 m 3 / h, the natural gas flow is controlled at 1.8 m 3 / h, the kiln pressure is controlled at -1 Pa, the opening degree of the branch pipe of the ignition valve of each zone is adjusted to 3%, the frequency of the exhaust fan is 30 Hz, the ratio of air to gas is 180:1, when the actual temperature of the point differs from the temperature of the main control point by 2 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 12 °C / h.

[0078] Zone 7: the combustion-supporting air flow is controlled at 290 m 3 / h, the temperature-adjusting air flow is controlled at 270 m 3 / h, the natural gas flow is controlled at 2 m 3 / h, the kiln pressure is controlled at -1 Pa, the opening degree of the branch pipe of the ignition valve of each zone is adjusted to 3%, the frequency of the exhaust fan is 30 Hz, the ratio of air to gas is 180:1, when the actual temperature of the point differs from the temperature of the main control point by 3 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 14 °C / h.

[0079] The other zones are adjusted according to the above-mentioned range.

[0080] From the inspection of the porcelain pieces, the qualified rate of the dry-process porcelain pieces is stably (97-98)%, and the qualified rate of the wet-process porcelain pieces is stably (97-98.5)%, which meets the expected effect.

[0081] Example 4

[0082] In the first stage, when the temperature is 50 °C or below, the combustion-supporting air flow of each zone of the kiln is controlled at (390-420) m 3 / h, the temperature-adjusting air flow is controlled at (340-360) m 3 / h, natural gas flow rate controlled at (1~1.5)m 3 / h, kiln pressure -0.2Pa, ignition valve branch pipe opening adjusted to 0%, flue gas fan frequency conversion 9Hz, air to gas ratio 260:1, when the actual temperature at the point differs from the intermediate main control point temperature by (5~8)℃, the kiln is in a relatively zero pressure state at this time. This operation is the basis for achieving quality control in the second stage. The heating rate in this stage is (8~10)℃ / h.

[0083] Zone 1: Combustion air flow rate controlled at 390m³ 3 / h, temperature-controlled airflow is maintained at 340m³ / h 3 / h, natural gas flow rate controlled at 1m 3 / h, kiln pressure -0.2Pa, ignition valve branch pipe opening adjusted to 0%, flue gas frequency converter 9Hz, air to gas ratio 260:1, when the actual temperature at point 7℃ differs from the intermediate main control point temperature, the kiln is in a relatively zero pressure state at this time, and the heating rate at this stage is 10℃ / h.

[0084] Zone 4: Combustion air flow rate controlled at 405m³ 3 / h, temperature-controlled airflow is maintained at 350m³ / h. 3 / h, natural gas flow rate controlled at 1.3m 3 / h, kiln pressure -0.2Pa, ignition valve branch pipe opening adjusted to 0%, flue gas frequency converter 9Hz, air to gas ratio 260:1, when the actual temperature at point 6℃ differs from the intermediate main control point temperature, the kiln is in a relatively zero pressure state at this time, and the heating rate at this stage is 9℃ / h.

[0085] Zone 7: Combustion air flow rate controlled at 420m³ 3 / h, temperature-controlled airflow is maintained at 360m³ / h. 3 / h, natural gas flow rate controlled at 1.5m 3 / h, kiln pressure -0.2Pa, ignition valve branch pipe opening adjusted to 0%, flue gas frequency converter 9Hz, air to gas ratio 260:1, when the actual temperature at point 8℃ differs from the intermediate main control point temperature, the kiln is in a relatively zero pressure state at this time, and the heating rate at this stage is 9℃ / h.

[0086] Other areas will be adjusted according to the range mentioned above.

[0087] In the second stage, the combustion air flow rate in each zone of the kiln is controlled at (51-95)℃ and (330-350)m³. 3 / h, temperature-regulating air volume controlled at (305~320)m³ 3 / h, natural gas flow rate controlled at (1.3~1.5)m 3 / h, the air-fuel ratio is 210:1, when the actual temperature of the firing point is different from the temperature of the main control point by (3-5) °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is (10-12) °C / h.

[0088] Zone 1: the combustion air flow is controlled at 330 m 3 / h, the temperature adjusting air flow is controlled at 305 m 3 / h, the natural gas flow is controlled at 1.3 m 3 / h, the kiln pressure is controlled at -4 Pa, the branch opening of the firing valve of each zone is adjusted to 1%, the frequency of the exhaust fan is 20 Hz, the air-fuel ratio is 210:1, when the actual temperature of the firing point is different from the temperature of the main control point by 5 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 12 °C / h.

[0089] Zone 4: the combustion air flow is controlled at 340 m 3 / h, the temperature adjusting air flow is controlled at 313 m 3 / h, the natural gas flow is controlled at 1.4 m 3 / h, the kiln pressure is controlled at -4 Pa, the branch opening of the firing valve of each zone is adjusted to 1%, the frequency of the exhaust fan is 20 Hz, the air-fuel ratio is 210:1, when the actual temperature of the firing point is different from the temperature of the main control point by 4 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 10 °C / h.

[0090] Zone 7: the combustion air flow is controlled at 350 m 3 / h, the temperature adjusting air flow is controlled at 320 m 3 / h, the natural gas flow is controlled at 1.5 m 3 / h, the kiln pressure is controlled at -4 Pa, the branch opening of the firing valve of each zone is adjusted to 1%, the frequency of the exhaust fan is 20 Hz, the air-fuel ratio is 210:1, when the actual temperature of the firing point is different from the temperature of the main control point by 5 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 12 °C / h.

[0091] The other zones are adjusted according to the above-mentioned range.

[0092] The third stage, (96-150) °C, the combustion air flow of each zone of the kiln is controlled at (290-300) m 3 / h, the temperature adjusting air flow is controlled at (270-280) m 3 / h, the natural gas flow is controlled at (2-2.5) m 3 / h, the opening degree of the branch pipe of the ignition valve of each zone is adjusted to 2%, the frequency of the exhaust fan is 25 Hz, the ratio of air to gas is 150:1, when the actual temperature of the firing point is different from the temperature of the main control point by (2-3) °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is (12-15) °C / h.

[0093] Zone 1: the combustion-supporting air flow is controlled at 290 m 3 / h, the temperature-adjusting air flow is controlled at 270 m 3 / h, the natural gas flow is controlled at 2 m 3 / h, the pressure in the kiln is controlled at -2 Pa. The opening degree of the branch pipe of the ignition valve of each zone is adjusted to 2%, the frequency of the exhaust fan is 25 Hz, the ratio of air to gas is 150:1, when the actual temperature of the firing point is different from the temperature of the main control point by 3 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 14 °C / h.

[0094] Zone 4: the combustion-supporting air flow is controlled at 295 m 3 / h, the temperature-adjusting air flow is controlled at 275 m 3 / h, the natural gas flow is controlled at 2.3 m 3 / h, the pressure in the kiln is controlled at -2 Pa. The opening degree of the branch pipe of the ignition valve of each zone is adjusted to 2%, the frequency of the exhaust fan is 25 Hz, the ratio of air to gas is 150:1, when the actual temperature of the firing point is different from the temperature of the main control point by 2 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 13 °C / h.

[0095] Zone 7: the combustion-supporting air flow is controlled at 300 m 3 / h, the temperature-adjusting air flow is controlled at 280 m 3 / h, the natural gas flow is controlled at 2.5 m 3 / h, the pressure in the kiln is controlled at -2 Pa. The opening degree of the branch pipe of the ignition valve of each zone is adjusted to 2%, the frequency of the exhaust fan is 25 Hz, the ratio of air to gas is 150:1, when the actual temperature of the firing point is different from the temperature of the main control point by 3 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 13 °C / h.

[0096] The other zones are adjusted according to the above-mentioned ranges.

[0097] From the inspection of the porcelain pieces, the qualified rate of the dry-process porcelain pieces is stably (96.5-97.5)%, the qualified rate of the wet-process porcelain pieces is stably (96-97.5)%, which basically meets the expected effect.

[0098] Example 5

[0099] In the first stage, 50 °C and below, the combustion-supporting air flow of each zone of the kiln is controlled at (390-420) m 3 / h, the temperature-adjusting air flow is controlled at (340-360) m3 / h, natural gas flow rate controlled at (1~1.5)m 3 / h, the pressure inside the kiln is controlled at 0Pa, the opening of the branch pipe of the ignition valve in each zone is adjusted to 0.5%, the frequency converter of the exhaust fan is 10Hz, the ratio of air to gas is 270:1, when the actual temperature at the point differs from the temperature at the intermediate main control point by (5~8)℃, the kiln is in a state of relative zero pressure. This operation is the basis for achieving quality control in the second stage. The heating rate in this stage is (8~10)℃ / h.

[0100] Zone 1: Combustion air flow rate controlled at 390m³ 3 / h, temperature-controlled airflow is maintained at 340m³ / h 3 / h, natural gas flow rate controlled at 1m 3 / h, kiln pressure 0Pa, ignition valve branch pipe opening adjusted to 0.5%, flue gas frequency conversion 10Hz, air to gas ratio 270:1, when the actual temperature at point 8℃ differs from the intermediate main control point temperature, the kiln is in a relatively zero pressure state, and the heating rate at this stage is 10℃ / h.

[0101] Zone 4: Combustion air flow rate controlled at 405m³ 3 / h, temperature-controlled airflow is maintained at 350m³ / h. 3 / h, natural gas flow rate controlled at 1.3m 3 / h, kiln pressure 0Pa, ignition valve branch pipe opening adjusted to 0.5%, flue gas frequency conversion 10Hz, air to gas ratio 270:1, when the actual temperature at point 5℃ differs from the intermediate main control point temperature, the kiln is in a relatively zero pressure state, and the heating rate at this stage is 8℃ / h.

[0102] Zone 7: Combustion air flow rate controlled at 420m³ 3 / h, temperature-controlled airflow is maintained at 360m³ / h. 3 / h, natural gas flow rate controlled at 1.5m 3 / h, kiln pressure 0Pa, ignition valve branch pipe opening adjusted to 0.5%, flue gas frequency conversion 10Hz, air to gas ratio 270:1, when the actual temperature at point 6℃ differs from the intermediate main control point temperature, the kiln is in a relatively zero pressure state at this time, and the heating rate at this stage is 10℃ / h.

[0103] Other areas will be adjusted according to the range mentioned above.

[0104] In the second stage, the combustion air flow rate in each zone of the kiln is controlled at (51-95)℃ and (330-350)m³. 3 / h, temperature-regulating air volume controlled at (305~320)m³ 3 / h, natural gas flow rate controlled at (1.3~1.5)m 3 / h, the air-fuel ratio is 220:1, when the actual temperature of the firing point is different from the temperature of the intermediate main control point by (3-5) °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is (10-12) °C / h.

[0105] Zone 1: the combustion air flow is controlled at 330 m 3 / h, the temperature adjusting air flow is controlled at 305 m 3 / h, the natural gas flow is controlled at 1.3 m 3 / h, the kiln pressure is controlled at -3 Pa, the branch opening degree of the firing valve of each zone is adjusted to 1.5%, the frequency of the exhaust fan is 23 Hz, the air-fuel ratio is 220:1, when the actual temperature of the firing point is different from the temperature of the intermediate main control point by 5 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 12 °C / h.

[0106] Zone 4: the combustion air flow is controlled at 340 m 3 / h, the temperature adjusting air flow is controlled at 313 m 3 / h, the natural gas flow is controlled at 1.4 m 3 / h, the kiln pressure is controlled at -3 Pa, the branch opening degree of the firing valve of each zone is adjusted to 1.5%, the frequency of the exhaust fan is 23 Hz, the air-fuel ratio is 220:1, when the actual temperature of the firing point is different from the temperature of the intermediate main control point by 3 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 11 °C / h.

[0107] Zone 7: the combustion air flow is controlled at 350 m 3 / h, the temperature adjusting air flow is controlled at 320 m 3 / h, the natural gas flow is controlled at 1.5 m 3 / h, the kiln pressure is controlled at -3 Pa, the branch opening degree of the firing valve of each zone is adjusted to 1.5%, the frequency of the exhaust fan is 23 Hz, the air-fuel ratio is 220:1, when the actual temperature of the firing point is different from the temperature of the intermediate main control point by 4 °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 11 °C / h.

[0108] In the third stage, (96-150) °C, the combustion air flow of each zone of the kiln is controlled at (290-300) m 3 / h, the temperature adjusting air flow is controlled at (270-280) m 3 / h, the natural gas flow is controlled at (2-2.5) m 3 / h, the kiln pressure is controlled at -1.5 Pa, the branch opening degree of the firing valve of each zone is adjusted to 2.5%, the frequency of the exhaust fan is 28 Hz, the air-fuel ratio is 165:1, when the actual temperature of the firing point is different from the temperature of the intermediate main control point by (2-3) °C, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is (12-15) °C / h.

[0109] Zone 1 : combustion air flow controlled at 290 m 3 / h, temperature control air flow controlled at 270 m 3 / h, natural gas flow controlled at 2 m 3 / h, kiln pressure controlled at -1.5 Pa, each zone ignition valve branch opening adjusted to 2.5%, exhaust fan frequency 28 Hz, air to gas ratio 165:1, when the actual temperature of the point and the intermediate main control point temperature difference 3°C, the kiln at this time in the relative zero pressure state, the heating rate of this stage 14°C / h, when the actual temperature of the point and the intermediate main control point temperature difference 3°C, the kiln at this time in the negative pressure state, the heating rate of this stage 14°C / h.

[0110] Zone 4: combustion air flow controlled at 295 m 3 / h, temperature control air flow controlled at 275 m 3 / h, natural gas flow controlled at 2.3 m 3 / h, kiln pressure controlled at -1.5 Pa, each zone ignition valve branch opening adjusted to 2.5%, exhaust fan frequency 28 Hz, air to gas ratio 165:1, when the actual temperature of the point and the intermediate main control point temperature difference 2°C, the kiln at this time in the negative pressure state, the heating rate of this stage 13°C / h.

[0111] Zone 7: combustion air flow controlled at 300 m 3 / h, temperature control air flow controlled at 280 m 3 / h, natural gas flow controlled at 2.5 m 3 / h, kiln pressure controlled at -1.5 Pa, each zone ignition valve branch opening adjusted to 2.5%, exhaust fan frequency 28 Hz, air to gas ratio 165:1, when the actual temperature of the point and the intermediate main control point temperature difference 2°C, the kiln at this time in the negative pressure state, the heating rate of this stage 15°C / h.

[0112] The other zones are adjusted according to the above mentioned range.

[0113] From the inspection of the porcelain pieces, the dry method porcelain piece porcelain inspection qualified rate is stable at (96-97)%, the wet method porcelain piece porcelain inspection qualified rate is stable at (96.5-97.5)%, basically in line with the expected effect.

[0114] Example 6

[0115] First stage, 50°C and below, kiln combustion air flow controlled at (390-420) m 3 / h, temperature control air flow controlled at (340-360) m 3 / h, natural gas flow controlled at (1-1.5) m 3 / h, the opening degree of the ignition valve branch pipe is adjusted to 1%, the frequency converter of the exhaust fan is 11 Hz, the ratio of air to gas is 275:1, when the actual temperature of the firing point and the temperature of the intermediate main control point differ by (5-8) °C, the kiln is in a relative zero pressure state at this time, and the temperature rising speed of this stage is (8-10) °C / h.

[0116] Zone 1: the combustion-supporting air flow is controlled at 390 m 3 / h, the temperature-adjusting air flow is controlled at 340 m 3 / h, the natural gas flow is controlled at 1 m 3 / h, the kiln pressure is 0.2 Pa, the opening degree of the ignition valve branch pipe is adjusted to 1%, the frequency converter of the exhaust fan is 11 Hz, the ratio of air to gas is 275:1, when the actual temperature of the firing point and the temperature of the intermediate main control point differ by 7 °C, the kiln is in a relative zero pressure state at this time, and the temperature rising speed of this stage is 10 °C / h.

[0117] Zone 4: the combustion-supporting air flow is controlled at 405 m 3 / h, the temperature-adjusting air flow is controlled at 350 m 3 / h, the natural gas flow is controlled at 1.3 m 3 / h, the kiln pressure is 0.2 Pa, the opening degree of the ignition valve branch pipe is adjusted to 1%, the frequency converter of the exhaust fan is 11 Hz, the ratio of air to gas is 275:1, when the actual temperature of the firing point and the temperature of the intermediate main control point differ by 6 °C, the kiln is in a relative zero pressure state at this time, and the temperature rising speed of this stage is 10 °C / h.

[0118] Zone 7: the combustion-supporting air flow is controlled at 420 m 3 / h, the temperature-adjusting air flow is controlled at 360 m 3 / h, the natural gas flow is controlled at 1.5 m 3 / h, the kiln pressure is 0.2 Pa, the opening degree of the ignition valve branch pipe is adjusted to 1%, the frequency converter of the exhaust fan is 11 Hz, the ratio of air to gas is 275:1, when the actual temperature of the firing point and the temperature of the intermediate main control point differ by 7 °C, the kiln is in a relative zero pressure state at this time, and the temperature rising speed of this stage is 10 °C / h.

[0119] The other zones are adjusted according to the ranges mentioned above.

[0120] The second stage is (51-95) °C, the combustion-supporting air flow of each zone of the kiln is controlled at (330-350) m 3 / h, the temperature-adjusting air flow is controlled at (305-320) m 3 / h, the natural gas flow is controlled at (1.3-1.5) m 3h, the pressure in the kiln is controlled at -2 Pa, the branch opening of the ignition valve in each zone is adjusted to 2%, the frequency of the exhaust fan is 25 Hz, the ratio of air to gas is 230:1, when the actual temperature at the point differs from the temperature at the main control point by (3-5) °C, the kiln is in a state of negative pressure at this time, and the temperature rising speed in this stage is (10-12) °C / h.

[0121] Zone 1: the combustion air flow is controlled at 330 m 3 / h, the temperature adjusting air flow is controlled at 305 m 3 / h, the natural gas flow is controlled at 1.3 m 3 / h, the pressure in the kiln is controlled at -2 Pa, the branch opening of the ignition valve in each zone is adjusted to 2%, the frequency of the exhaust fan is 25 Hz, the ratio of air to gas is 230:1, when the actual temperature at the point differs from the temperature at the main control point by 4 °C, the kiln is in a state of negative pressure at this time, and the temperature rising speed in this stage is 12 °C / h.

[0122] Zone 4: the combustion air flow is controlled at 340 m 3 / h, the temperature adjusting air flow is controlled at 313 m 3 / h, the natural gas flow is controlled at 1.4 m 3 / h, the pressure in the kiln is controlled at -2 Pa, the branch opening of the ignition valve in each zone is adjusted to 2%, the frequency of the exhaust fan is 25 Hz, the ratio of air to gas is 230:1, when the actual temperature at the point differs from the temperature at the main control point by 3 °C, the kiln is in a state of negative pressure at this time, and the temperature rising speed in this stage is 10 °C / h.

[0123] Zone 7: the combustion air flow is controlled at 350 m 3 / h, the temperature adjusting air flow is controlled at 320 m 3 / h, the natural gas flow is controlled at 1.5 m 3 / h, the pressure in the kiln is controlled at -2 Pa, the branch opening of the ignition valve in each zone is adjusted to 2%, the frequency of the exhaust fan is 25 Hz, the ratio of air to gas is 230:1, when the actual temperature at the point differs from the temperature at the main control point by 5 °C, the kiln is in a state of negative pressure at this time, and the temperature rising speed in this stage is 12 °C / h.

[0124] The other zones are adjusted according to the ranges mentioned above.

[0125] In the third stage, (96-150) °C, the combustion air flow in each zone of the kiln is controlled at (290-300) m 3 / h, the temperature adjusting air flow is controlled at (270-280) m 3 / h, the natural gas flow is controlled at (2-2.5) m 3 / h, the opening degree of the branch pipe of the ignition valve of each zone is adjusted to 3%, the frequency of the exhaust fan is 30Hz, the ratio of air to gas is 180:1, when the actual temperature of the point differs from the temperature of the main control point by (2-3)℃, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is (12-15)℃ / h.

[0126] Zone 1: the combustion air flow is controlled at 290m 3 / h, the temperature adjusting air flow is controlled at 270m 3 / h, the natural gas flow is controlled at 2m 3 / h, the kiln pressure is controlled at -1Pa, the opening degree of the branch pipe of the ignition valve of each zone is adjusted to 3%, the frequency of the exhaust fan is 30Hz, the ratio of air to gas is 180:1, when the actual temperature of the point differs from the temperature of the main control point by 3℃, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 13℃ / h.

[0127] Zone 4: the combustion air flow is controlled at 295m 3 / h, the temperature adjusting air flow is controlled at 275m 3 / h, the natural gas flow is controlled at 2.3m 3 / h, the kiln pressure is controlled at -1Pa, the opening degree of the branch pipe of the ignition valve of each zone is adjusted to 3%, the frequency of the exhaust fan is 30Hz, the ratio of air to gas is 180:1, when the actual temperature of the point differs from the temperature of the main control point by 3℃, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 14℃ / h.

[0128] Zone 7: the combustion air flow is controlled at 300m 3 / h, the temperature adjusting air flow is controlled at 280m 3 / h, the natural gas flow is controlled at 2.5m 3 / h, the kiln pressure is controlled at -1Pa, the opening degree of the branch pipe of the ignition valve of each zone is adjusted to 3%, the frequency of the exhaust fan is 30Hz, the ratio of air to gas is 180:1, when the actual temperature of the point differs from the temperature of the main control point by 3℃, the kiln is in a negative pressure state at this time, and the temperature rising speed in this stage is 15℃ / h.

[0129] The other zones are adjusted according to the above-mentioned range.

[0130] From the inspection of the porcelain pieces, the qualified rate of the dry-process porcelain pieces is stably (96-98)%, the qualified rate of the wet-process porcelain pieces is stably (97-98)%, which basically meets the expected effect.

[0131] The above-mentioned is only the preferable specific embodiment of the present application, but the protection scope of the present application is not limited to this, any change or replacement which can be easily thought of by the person skilled in the art within the technical range disclosed by the present application should be covered in the protection scope of the present application.

Claims

1. A method for low-temperature firing of mixed ceramic blanks, characterized in that, It includes three stages: In the first stage, at 50℃ and below, the flow rate of combustion air, the flow rate of temperature regulating air, the flow rate of natural gas, the pressure inside the kiln, and the opening degree of the branch pipe of the ignition valve in each zone are controlled so that the actual temperature at the current point is (5~8)℃ different from the temperature at the intermediate main control point, the kiln is in a relatively zero pressure state, and the heating rate is (8~10)℃ / h. In the second stage, at (51-95)℃, the flow rate of combustion air, the flow rate of temperature regulating air, the flow rate of natural gas, the pressure inside the kiln, and the opening degree of the branch pipe of the ignition valve in each zone are controlled so that the actual temperature at the current point is (3-5)℃ different from the temperature at the intermediate main control point, the kiln is in a negative pressure state, and the heating rate is (10-12)℃ / h. In the third stage, at (96-150)℃, the flow rate of combustion air, the flow rate of temperature regulating air, the flow rate of natural gas, the pressure inside the kiln, and the opening degree of the branch pipe of the ignition valve in each zone are controlled so that the actual temperature at the current point is (2-3)℃ different from the temperature at the intermediate main control point, the kiln is in a negative pressure state, and the heating rate is (12-15)℃ / h. The mixed porcelain blanks are porcelain blanks produced by dry and wet methods.

2. The low-temperature firing method for mixed ceramic blanks according to claim 1, characterized in that, In the first stage, the combustion air flow rate in each zone of the kiln is (360~420) m³ / h, the temperature regulating air flow rate is (320~360) m³ / h, the natural gas flow rate is (0.5~1.5) m³ / h, the pressure inside the kiln is (-0.2~+0.2) Pa, and the opening degree of the ignition valve branch pipe in each zone is adjusted to (0~1.0)%.

3. The low-temperature firing method for mixed ceramic blanks according to claim 1, characterized in that, In the second stage, the combustion air flow rate in each zone of the kiln is (310~350) m³ / h, the temperature regulating air flow rate is (290~320) m³ / h, the natural gas flow rate is (1.0~1.5) m³ / h, the pressure inside the kiln is (-4~-2) Pa, and the opening of the branch pipe of the ignition valve in each zone is adjusted to (1.0~2.0)%.

4. The low-temperature firing method for mixed ceramic blanks according to claim 1, characterized in that, In the third stage, the combustion air flow rate in each zone of the kiln is (280~300) m³ / h, the temperature regulating air flow rate is (260~280) m³ / h, the natural gas flow rate is (1.5~2.5) m³ / h, the pressure inside the kiln is (-2~-1) Pa, and the opening degree of the ignition valve branch pipe in each zone is adjusted to (2.0~3.0)%.

5. The low-temperature firing method for mixed ceramic blanks according to claim 1, characterized in that, During the first stage of firing, the frequency range of the exhaust fan is controlled at (9-11) Hz, and the ratio of air to gas is (260-275):

1.

6. The low-temperature firing method for mixed ceramic blanks according to claim 1, characterized in that, During the second stage of firing, the frequency range of the exhaust fan is controlled within (20~25) Hz.

7. The low-temperature firing method for mixed ceramic blanks according to claim 1, characterized in that, During the third stage of firing, the frequency range of the exhaust fan is controlled within (25~30) Hz.

8. The low-temperature firing method for mixed ceramic blanks according to claim 1, characterized in that, During the second stage of firing, the ratio of air to fuel gas is (210-230):

1.

9. The low-temperature firing method for mixed ceramic blanks according to claim 1, characterized in that, During the third stage of firing, the ratio of air to fuel gas is (150-180):

1.

10. The low-temperature firing method for mixed ceramic blanks according to claim 1, characterized in that, The kiln is divided into zones, and during each firing stage, the flow rate of combustion air, temperature regulating air, natural gas flow rate, and the opening degree of the ignition valve branch pipe are adjusted according to the different positions of the porcelain blanks in the kiln.