Background technology
72000 tons of prebaked anode roasting system's year design production capacities, two flame systems, the unlimited ring-form calcining furnace of 34 furnace chambers, the anode-baking furnace gas burning system software that domestic carbon industry furnace chamber of the same type generally adopts French SETRAM company to provide, 168~192 hours firing cycle heating curves under this software is supported, be the flame movement cycle between 28~32 hours, do not retrieve research data about 26 hours flame movement cycle roasting heating curves.Wherein: 28 hours flame movement cycles (promptly 168 hours firing cycle heating curves) output, energy consumption and curve setting are as follows:
1. output: according to 28 hours flame movement computation of Period output, 8 hoppers of each furnace chamber, each hopper is upright adorns 3 layers, i.e. 21 charcoal pieces, each furnace chamber is adorned 130.2 tons, supposes yield rate 95%, consider flue of needs cleaning in a year, the actual production time calculates by 345, and for the unlimited ring-form calcining furnace of 2 flame systems, whole year production charcoal piece total amount is:
345 (my god) * 24 (hour) ÷ 28 (hour) * 2 (system) * 130.2 (ton) * 95%=73154 tons
2. energy consumption: roasting Sweet natural gas unit consumption 97~100Nm
3/ ton, mean value is 98.5Nm
3/ ton.
3. curve setting: 28 hours flame movement during the cycle roasting heating curve formulate see the following form (table one, table two):
Product 28 T1 temperature setting programs (table one)
The segment sequence number | Time | Temperature set points (℃) | The temperature difference upper limit (℃) | Temperature difference lower limit (℃) |
1 | 00:00 | 260 | 30 | 30 |
2 | 01:00 | 290 | 30 | 30 |
3 | 10:00 | 400 | 30 | 30 |
4 | 15:00 | 450 | 30 | 30 |
5 | 25:00 | 540 | 30 | 30 |
6 |
26:00 |
550 |
30 |
30 |
7 |
28:00 |
580 |
30 |
30 |
Product 28 T4 T5 T6 temperature setting programs (table two)
The segment sequence number | Time | Temperature set points (℃) | The temperature difference upper limit (℃) | Temperature difference lower limit (℃) |
1 | 00:00 | 800 | 15 | 15 |
2 | 00:30 | 807 | 15 | 15 |
3 | 04:00 | 850 | 15 | 15 |
4 | 08:00 | 890 | 15 | 15 |
5 | 28:00 | 1035 | 15 | 15 |
6 | 56:00 | 1145 | 15 | 15 |
7 | 84:00 | 1145 | 15 | 15 |
4. 28 hours flame movement, 34 Room stoving oven horizontal distribution (table three) during the cycle
34 Room stoving oven flat distribution maps (table three)
18 sealings | 19 ER | 20 | 21 | 22 HR1 | 23 HR2 | 24 HR3 | 25 | 26 | 27 | 28 BR | 29 | 30 CR | 31 | 32 CR | 33 come out of the stove | 34 shove charges |
17 shove charges | 16 come out of the stove | 15 CR | 14 | 13 CR | 12 | 11 BR | 10 | 9 | 8 | 7 HR3 | 6 HR2 | 5 HR1 | 4 | 3 | 2 ER | 1 sealing |
5. the parameter regulation table (table four) that adopts of 28 hours periods
P.I.D coefficient adjustment table (table four)
Above-mentioned 28 hours roasting heating process, longer relatively because of its firing cycle, directly have influence on the production capacity and the energy consumption of roasting prebaked anode.
Summary of the invention
The object of the present invention is to provide and a kind ofly can guarantee under the product quality premise, shorten firing cycle, realize the prebaked-anode baking heating-up technology that increases production capacity, cuts down the consumption of energy.
For achieving the above object, the technical scheme taked of the present invention is:
A kind of prebaked-anode baking heating-up technology is characterized in that: adopt 26 hours roasting heating process (promptly 26 hours flame movement cycles), firing cycle is 156 hours, and the roasting heating process curve is provided with as following table:
Product 26 T1 temperature setting programs (table five)
The segment sequence number | Time | Temperature set points (℃) | The temperature difference upper limit (℃) | Temperature difference lower limit (℃) |
1 | 00:00 | 310 | 15 | 30 |
2 | 03:00 | 350 | 15 | 30 |
3 | 26:00 | 700 | 15 | 30 |
Product 26 T4 T5 T6 degree setting programs (table six)
The segment sequence number | Time | Temperature set points (℃) | The temperature difference upper limit (℃) | Temperature difference lower limit (℃) |
1 | 00:00 | 860 | 25 | 25 |
2 | 02:00 | 890 | 25 | 25 |
3 | 08:00 | 940 | 25 | 25 |
4 | 20:00 | 1050 | 25 | 25 |
5 | 26:00 | 1100 | 25 | 25 |
6 | 52:00 | 1150 | 25 | 25 |
7 | 78:00 | 1150 | 25 | 25 |
That is: the temperature rise rate of T1 was controlled between 310 ℃~350 ℃ in 0:00~3:00 time period, and the temperature difference is controlled between 350 ℃~700 ℃ in 3:00~26:00 time period between+15 ℃~-30 ℃, and the temperature difference is between+15 ℃~-30 ℃; T4, T5, the temperature rise rate of T6 is controlled at 860 ℃~890 ℃ in 00:00~02:00 time period, the temperature difference is between+25 ℃~-25 ℃, be controlled at 890 ℃~940 ℃ in 02:00~08:00 time period, the temperature difference is between+25 ℃~-25 ℃, be controlled at 940 ℃~1050 ℃ in 08:00~20:00 time period, the temperature difference is between+25 ℃~-25 ℃, be controlled at 1050 ℃~1100 ℃ in 20:00~26:00 time period, the temperature difference is between+25 ℃~-25 ℃, be controlled at 1100 ℃~1150 ℃ in 26:00~52:00 time period, the temperature difference is between+25 ℃~-25 ℃, be controlled at 1150 ℃~1150 ℃ in 52:00~78:00 time period, the temperature difference is between+25 ℃~-25 ℃.
Above-mentioned prebaked-anode baking heating-up technology provided by the invention, by adopting 26 hours roasting heating process (promptly 26 hours flame movement cycles, 156 hours firing cycle curves), to shorten firing cycle is main path, for 72000 tons of year design production capacities, 34 Room prebaked anode roaster furnaces of 2 flame systems, under the prerequisite that guarantees quality of prebaked anode, reach to exceed and design production capacity more than 5000 tons, roasting Sweet natural gas unit consumption on average reduces 7Nm
3The target of/ton.This has not only increased prebaked anode carbon piece output, and has reduced energy consumption, has obtained favorable economic benefit.Concrete numerical evaluation is as follows:
1. output: according to 26 hours flame movement computation of Period output, 8 hoppers of each furnace chamber, each hopper is upright adorns 3 layers, i.e. 21 charcoal pieces, each furnace chamber is adorned 130.2 tons, supposes yield rate 95%, consider flue of needs cleaning in a year, the actual production time calculates by 345, and for the unlimited ring-form calcining furnace of 2 flame systems, whole year production charcoal piece total amount is:
345 (my god) * 24 (hours) ÷ 26 (hour) * 2 (system) * 130.2 (ton) * 95%=78781 tons produce every year more: 78781 tons-73154 tons=5627 tons; With sale, 750 yuan of/ton expectations of net profit after tax, annual fecund is given birth to 4,220,000 yuan of the net profit output values.
2. energy consumption: 26 hours flame movement cycle roasting Sweet natural gas unit consumption 90~93Nm
3/ ton, mean value is 91.5Nm
3/ ton calculates, and has reduced 7Nm than 28 hours flame movement cycle roasting gas consumptions
3/ ton is 0.76 yuan/Nm with the Sweet natural gas unit price
3Meter, the pre-baked anode carbon blocks expense of reducing cost per ton is: 0.76 yuan/Nm
3* 7Nm
3/ ton=5.32 yuan/ton, every year, the expense of reducing cost was: 5.32 yuan/ton * 78781 tons=41.9 ten thousand yuan.
Embodiment
26 hours provided by the invention roasting heating process (promptly 26 hours flame movement cycles, 156 hours firing cycle curves) adopt on the basis in 28~32 hours flame movement cycles, may produce more following problems:
1, after roasting time shortens, on original technology basis, will cause the charcoal piece to burn not " ripe ", the situation that physical and chemical indexs such as resistivity, ultimate compression strength descend.
2, owing to reduce cooling time, the tapping temperature height, to multifunction crane come out of the stove, compile separate group job, the furnace retaining operation is made troubles, even can damage equipment.
3, on the basis of original negative pressure, because of firing cycle shortens, preheating furnace chamber heat-up rate can not satisfy heating process.
Can 4, because of firing cycle shortens, the firing system rate of heating will be accelerated, regulate station power divider, PTD (proportional integral) adjusting and P+T (negative pressure, temperature integrated adjusting) and satisfy the demand.
For this reason, the present invention studies burning position and each stage heat-up rate of the original technology of whole roasting, fugitive constituent in the specific implementation process of 34 Room prebaked anode roaster furnaces of 72000 tons of production capacities of year design, two flame systems; Each link that influences technology, quality is tackled key problems, and the every index after technical scheme implemented carried out the demonstration of science,, adopted following method to settle one by one by further adjustment:
At problem 1: mainly be by improving the roasting bulk temperature, T4 promptly is in the temperature in charcoal lump coke stage, brings up to 1100 ℃ by original 1050 ℃, prolong the soaking time of charcoal piece in the coking stage, guarantee the thermoosmosis of heat, make the thorough coking of charcoal piece internal bond agent the charcoal piece; With T1 is the temperature eventually of preheating furnace chamber, by original 620 ℃, bring up to 700 ℃ with the speed in 20 ℃/cycle, to change the position that fugitive constituent overflows in a large number in furnace chamber, it just in time is in T3~T2 (second, third preheating furnace chamber) furnace chamber greater than the fugitive constituent burning-point, can heats up the heat deposit is provided for the later stage on the one hand, make the fully burning on the spot of a large amount of fugitive constituents on the other hand, to reduce unit consumption of fuel, can alleviate the pressure of smoke evacuation frame and purification system simultaneously.
But owing to fugitive constituent overflows in advance, if system's negative pressure regulation range does not guarantee that occur the phenomenon of string Sweet natural gas probably, when whole temperature, owing to T1 has reached 700 ℃, system can often catch fire.Qingtongxia Aluminium Smeltery invites French SETRAM company once with after the T1 temperature regulation to 700 ℃, and the number of times that catches fire weekly just reaches 2~3 times, causes very big loss.At ignition issues, we to the negative pressure regulation range by originally-50Pa~-150Pa is increased to-80Pa~-180Pa, with zero-pressure frame ZPR set(ting)value by originally+5Pa is increased to+15Pa.Its objective is to make Sweet natural gas and fugitive constituent that competent oxygen be arranged in the combustion zone, cross oxygen quotient at the waste gas discharge area and reduce to minimum.Under normal conditions, judge according to the color of combustion of natural gas flame: the combustion of natural gas flame is light blue, and air is suitable; Combustion of natural gas flame is white in color, air excess; The combustion of natural gas flame is orange, lack of air; Also can by pinkeye lid down fugitive constituent burning flash-point how much come to determine the peroxide amount, as shown in Figure 1: flash-point is few, it is not obvious to catch fire, the oxygen-supplying amount deficiency.
Regulate by long period, catch fire the flash-point position control below 2P the 2nd vision slit when roasting is warm eventually, accomplish the end in view, as shown in Figure 2: flash-point is many, and it is not obvious to catch fire, and oxygen-supplying amount is suitable.
Through each link temperature raising is regulated, solved the charcoal piece and burnt not " ripe ", the problem that physical and chemical indexs such as resistivity, ultimate compression strength descend.11~December in 2005, charcoal piece physics and chemistry statistical indicator saw Table seven:
Prebaked anode survey report (table seven)
Numbering | Volume density | True specific gravity | Intensity | Resistivity | Grade |
173266 | 1.54 | 2.03 | 44 | 55 | One-level |
175075 | 1.56 | 2.03 | 42 | 54 | One-level |
66276 | 1.53 | 2.05 | 42 | 54 | One-level |
041213 (little) | 1.55 | 2.04 | 42 | 55 | One-level |
65377 | 1.54 | 2.05 | 39 | 55 | One-level |
69936 | 1.57 | 2.04 | 45 | 54 | One-level |
62074 | 1.53 | 2.06 | 41 | 56 | Secondary |
88800 | 1.54 | 2.03 | 48 | 52 | One-level |
041101 (little) | 1.56 | 2.05 | 49 | 54 | One-level |
Mean value | 1.547 | 2.042 | 43.556 | 54.333 | One-level |
At problem 2: every shortening of roasting flame movement cycle 2 hours, (168 hours~156 hours) force cooling time will to shorten 12 hours for each cooling furnace chamber, the hopper temperature is up to more than 400 ℃ when coming out of the stove, multifunction crane can't works better, especially in summer, very big to material sucking pipes and the damage of overhead traveling crane induction installation, the charcoal deblocking temperature exceeded than 28 hours about 50 ℃~100 ℃ simultaneously, system of solutions optoelectronic switch and the roasting disconnected phenomenon of signal wire quilt often occurred compiling.Can't enter the hopper operation for the furnace retaining operating personnel, and then influence multifunction crane shove charge operation.In order to solve the cooling problem, 1,2 systems are changed to Room 9 (19~27,28~32) runnings (table nine) { system's running furnace chamber changes the computer program that must revise in the anode-baking furnace gas burning system } by original Room 10 (19~28,29~32) runnings (table eight), increase the cooling furnace chamber, prolong relatively and force 26 hours cooling times, preferably resolve the high problem of furnace chamber temperature.
28 hours flame movement, 34 Room stoving oven horizontal distribution (table eight) during the cycle
18 sealings | 19 ER | 20 | 21 | 22 HR1 | 23 HR2 | 24 HR3 | 25 | 26 | 27 | 28 BR | 29 | 30 CR | 31 | 32 CR | 33 come out of the stove | 34 shove charges |
17 shove charges |
16 come out of the stove |
15 CR |
14 |
13 CR |
12 |
11 BR |
10 |
9 |
8 |
7 HR3 |
6 HR2 |
5 HR1 |
4 |
3 |
2 ER |
1 sealing |
26 hours flame movement, 34 Room stoving oven horizontal distribution (table nine) during the cycle
18 sealings | 19 ER | 20 | 21 | 22 HR1 | 23 HR2 | 24 HR3 | 25 | 26 | 27 BR | 28 | 29 CR | 30 | 31 CR | 32 | 33 come out of the stove | 34 shove charges |
|
17 shove charges | 16 come out of the stove | 15 | 14 CR | 13 | 12 CR | 11 | 10 BR | 9 | 8 | 7 HR3 | 6 HR2 | 5 HR1 | 4 | 3 | 2 ER | 1 sealing |
At problem 3: shortening all after dates, heat-up rate will be accelerated, needing a large amount of fuel and fugitive constituent within a certain period of time fully burns, under the changeless situation in quirk combustion space, a large amount of oxygen need be provided, test through nearly two cycles shows, only improve negative pressure and can bring the fugitive constituent reach, be unfavorable for system's normal operation, therefore we are set at 95% by the power of fan with the BR frame, the windsurfing block of valve of CR (forcing cooling) frame fixes on maximum position, come the supplemental oxygen deficiency by strengthening blast volume, not only solved the oxygen supply problem, simultaneously the air that enters quirk has been shifted to an earlier date preheating, reduced in the heating zone and the preheating zone freezing air absorption energy consumption that heat caused.So, can allow fugitive constituent burn in advance relatively, remedy the problem that preheating furnace chamber heat-up rate can not satisfy the heating curve requirement at the preheating furnace chamber.
At problem 4: because adjusting station power divider, PID (proportional integral) in the anode-baking furnace gas burning system that French SETRAM company provides regulate and P+T (negative pressure, temperature integrated adjusting) is a close loop negative feedback regulation system, its characteristic and parameter value are generally recommended by software company.The characteristic of our factory and parameter value are the empirical value of charcoal piece composition through drawing after repeatedly adjusting, and each adjustment amount is controlled between 1~2, also can provide Principles of Regulation with reference to following (A, B, C) matrix integral formula in real work:
The A formula: Cv=Kc[(E)+1/Ti ∫
0 1(E) dt+Td*D (pv)/dt]+skew
In the formula: t is a time variable, and E is error (Pv-Sp); K is a coefficient: generally get 0.6~0.8; Other alphabetical implications can find it to represent meaning in anode-baking furnace gas burning system software.
B formula: temperature PID is used to calculate PT1, BU1, BU2, BU3 order, and it mainly depends on the value of temperature T 1, T4, T5, T6, and it is constructed as follows:
PT(x)=KPt*ET(x)+KIt*d{ET(x)/dt}+KDt*d
2{ET(x)/dt
2}
BU(x)=KPt*ET(x)+KIt*d{ET(x)/dt}+KDt*d
2{ET(x)/dt
2}
C formula: pressure P ID is used to calculate EX and BL order, and it mainly depends on the value of temperature P1, P6, and it is constructed as follows:
EX=KPp*EP(x)+Kip*Ep(x)+KDp*Ep(x)
BL=KPp*EP(x)+Kip*Ep(x)+KDp*Ep(x)
, adjust by the Comparative Examples value parameter under the constant prerequisite of integral parameter keeping for this reason, draw to draw a conclusion:
1. 28 hours flame movement cycles were adopted table ten parameter, and system keeps track is more stable;
2. 26 hours flame movement cycles were adopted table ten parameter, and system keeps track is more stable.
P.I.D coefficient adjustment table (table ten)
P.I.D coefficient adjustment table (table ten one)
For P+T mode (adjusting of temperature negative pressure), after the time shortens, must take into full account the negative pressure maximin.Shown in table ten two, increase relatively on the one hand because of the fugitive constituent spillage, the negative pressure maximum value should remain on-more than the 80Pa, produces blast when avoiding the too much or system of entrap bubble undesired.Minimum value should remain on-below the 180Pa, prevent that excessive negative pressure from bringing the single fire passage overtemperature; Also need consider burner power maximum value on the other hand, though power can improve heat-up rate greatly, can not guarantee that Sweet natural gas fully burns, maximum harm is can cause Sweet natural gas to collaborate to catch fire.By long period test, negative pressure, power adopt table ten two parameter effects better.
Press at the angle, power parameter table (table ten two)
| LIMITS | Backup Values by Flue Wall |
ACTUATORS | Min | Max | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
EX(%) | 20 | 95 | 75 | 75 | 75 | 75 | 75 | 75 | 75 | 75 | 75 |
BU1(%) | 5 | 70 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 |
BU2(%) | 5 | 75 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 |
BU3(%) | 5 | 75 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 | 15 |
BL(%) | 25 | 95 | 50 | 50 | 50 | 50 | 50 | 50 | 50 | 50 | 50 |
PT1(Pa) | -180 | -80 | Burner ratio in backup mode | 50 |