The iron and steel plant by its resources
crowded, the energy consumption crowded, the production scale big, the
thing flows the volume of goods handled in a big way and so on the
characteristic, since long ago was continuously considered is the mist
and dust withdrawal big, the reject are many, pollutes the big
enterprise. But the arc furnace steel-making is some iron and
steel plants creates one of mist and dust pollution main origins.
The arc furnace (is called electric stove) mainly is through
uses the scrap steel, the ferroalloy and the partial dregs material
carries on ingredient smelting, according to the different aluminum
request, may accept Gao Tange the molten iron and the
dephosphorization molten iron, then the melt generating carbon steel
or the stainless steel molten steel for build up casts uses. The
electric stove makes steel when produces the harmful pollution mainly
manifests in the electric stove feeds in raw material, smelting, the
tapping three stages. The electrosmelting generally divides into
熔化? 氧化?and 还原? 氧化?strengthening 脱炭,
because blows the oxygen or adds the ore to produce the massive
russets thick smoke. In the above three smelting time, the smoke
spirit which 氧化?produces biggest, contains the dust density and
the haze temperature is highest. Therefore, electric stove dust
removal system according to 氧化?the maximum mist and dust
displacement carries on the design. Increases security threshold
in the system greatest amount of wind demand foundation which 1.1~1.3
doubles to carry on the dust removal air blower shaping design.
In the entire steel-making process blows the oxygen time to
account for 30~35%, this time the air blower is in the higher load
movement, but other time are in the lower movement operating mode.
The dust removal system use factor very is very obviously low
also the system effect rate difference.
Since long ago, which movement stage no matter is the electric
stove at, produces the dust size causes to remove dust the air blower
full speed movement, uses the entrance back plate to open an
adjustment lowly, the efficiency, the power is big, creates the
massive electrical energies waste. Unceasingly intensifies along
with the market competition, the energy conservation falls consumes,
the enhancement production efficiency becomes the enterprise to
develop one of enhancement competitive ability effective methods.
But started the widespread application high-pressured high
efficiency frequency conversion velocity modulation technology in the
90's adapted the market demand, obtained the unceasing progress and
the development in the technology and the application domain.
Now, widely has applied to the electric power, the petroleum
chemical industry, the mine, the metallurgy, for draining water, the
locomotive tows and so on the domain.
Daye special steel group some steel mill is precisely under this
kind of condition, conducts the high-pressured frequency conversion
technological transformations research to the electric stove dust
removal system. This arc furnace dust removal system structure
following chart one shows. The electric stove in smelting
process dust mainly through the furnace top smoke Daoist scriptures
沉降?deposition, after the water cooling wall cools filters after
the dust removal system discharges; Simultaneously uses
集尘?walks the scene production workshop dust and the waste gas
prompt platoon, in order to avoid endangers the electric stove
peripheral staff the security, the pollution environment.
Removes dust the air blower is the main equipment which
discharges the haze absorption. A chart arc furnace dust removal
system structure drawing two, system technology plan research:
The Daye special steel group some steel mill #8 electric stove
for expands the 70tABB exchange arc furnace which accommodates.
The dust remover system uses the TFMC cloth sack type dust
remover, the design filters area 11985m2, biggest dust removal amount
of wind 450000m3/h.
The #8 electric stove steel-making cycle is the 70~85 minute, in
which feeds 6~10%, the power transmission melts 25~30%, blows oxygen
30~35%, 还原?15~20%, 冲渣 tapping 6~8%. In the different
production craft stage, the smoke spirit and the haze temperature
which the electric stove produces different, also the difference is
bigger. Feeds in raw material in the process, mainly is feeds
when the scrap steel and the dregs material produces raises the dust,
needs the dust removal amount of wind is not big, the request dust
non-proliferation, does not pollute the electric stove peripheral
working conditions is a standard. In the power transmission
process is the raw material power transmission pulls the arc to heat
up, initiation inflammable reject burning produces the waste gas.
This time, the electric stove needs to heat up the furnace
charge to the melting condition, the request mist and dust can
promptly discharge, also cannot excessively many carry off the furnace
body quantity of heat to guarantee the steel-making cycle. But
is blowing oxygen period, not only the request dust removal system can
prompt be rapid walks the waste gas and the dust platoon, also must
guarantee the furnace body has the appropriate blowing temperature,
guarantees the outlet temperature. Therefore, to removes dust
the system request to be higher. Enters 还原? blows the
oxygen to be completed, dust reduces once again. When 冲渣
tapping, mainly discharges the steam and the few waste gas which the
thing is 冲渣 produces.
Through to smelts the craft the analysis: The electric
stove to removes dust the amount of wind in the steel-making process
different stage the size to have the obvious difference, take blows
oxygen smelting as in a big way, feeds in raw material the dust
removal for to be lowest. In view of the fact that in the
electric stove dust removal system removes dust the air blower the
movement way and the equipment characteristic, to removes dust the air
blower the control formulation following plan. 2.1 equipment
parameters: Dust removal air blower parameter: Electric
motor parameter: Thermistor cabinet parameter: Frequency changer technical specification: Model:
Y4-73 No31.5F model: Y6304-8
model: HTR 5-2 model: Harsvert-A06/220
current capacity: 456200m3/h rated voltage:
6000V rated voltage: 6000V input voltage: 6000V wind
pressure: 352kPa nominal current: 185A nominal current: 200A nominal current: 220A
轴转? 730r/min rated speed: 741r/min nominal frequency: 50Hz nominal
frequency: 50Hz shaft power: 1470kW rated power:
1600kW rated capacity: 2000kVA output
voltage: 0~6000V output frequency: 0~50Hz rated capacity:
2000kVA2 2 system electricity constitution
According to the scene production craft situation,
selects 利德 the Chinese luck production Harsvert-A frequency
changer to make primarily, this frequency conversion velocity
modulation system has the harmonic content slightly, the power factor
high, the programming nimble, the ease of operation, the modular
structure, the failure rate low, exempt the maintenance, is easy to
service and so on the characteristic. The dust removal air
blower electrical system main wiring structure drawing like chart two
shows. The 6kV power source turns on the system through female
line segment network side high-voltage switch DL, uses multiple moves
the coherent insulating transformer to carry on the power source side
electricity isolation, reduces to the electrical network overtone
pollution; The transformer outputs after the power cabinet
inversion output the direct drive three-phase asynchronous motor, the
realization dust removal amount of wind control. In order to
guarantee the dust removal air blower safe reliable movement, system
design labor/frequency conversion two sets of dynamic systems.
When system frequency conversion movement, separation isolator
QS21, QS22; Gathers isolator QS11, QS12. Opens by the
frequency changer stops the equipment, the realization removes dust
the air blower the rotational speed and the amount of wind control.
When the frequency conversion line appears the breakdown, system
cut to original labor frequency movement way; Separation
isolator QS11, QS12; Gathers isolator QS21, QS22. Starts
the air blower by the original dust removal system through the
thermistor cabinet, the entrance back plate control amount of wind.
The chart two dust removal air blowers electrical system main
wiring structure drawing 2.3 systems controls plan because the
different craft stage haze temperature has the obvious difference,
therefore the temperature height has directly reflected the electric
stove movement operating mode. The system has not certainly used
in the examination electric stove work the dust density way to come
the positive governing dust removal amount of wind, but is gathers a
smoke temperature to take the system adjustment the basic parameter,
infers under the different movement operating mode through the
nonlinear function relations the dust removal amount of wind
participation systems control. Says from the project angle, the
temperature changes delivering to be allowed in the bad industry
situation application, the antijamming ability strong, the work
stability good, the control precision high, safe reliable, to exempt
the maintenance also the price is cheap. But the dust density
detector set price expensive, the stability bad, the failure rate
high, the maintenance quantity big, the scene 检?data
acquisition is very difficult to have shortcoming and so on widespread
representation. Based on the above reason, selects the dust
removal smoke haze temperature to take the scene process quantity.
At the same time, blows the oxygen quantity and the cold air
throttle opens to repair and maintain the parameter as the dust
removal amount of wind, thus enhances the system speed of response,
the improvement control quality, achieved the good dust removal
effect, the realization dust removal amount of wind automatic control,
reduces the movement personnel labor intensity, enhances the system
efficiency, achieves the best electricity saving effect. The
concrete control logic sees the chart three to show. Chart
three
In order to guarantee the system the reliability,
moreover increased the dust removal amount of wind hand control return
route, to removes dust the amount of wind the control to use the
partition velocity modulation the way by the stove in front of the
control desk control frequency conversion movement frequency spot,
thus realizes under the different movement operating mode amount of
wind adjustment. The control logical diagram like chart four
shows. Chart four
The practice proved that, The system after
designed two sets of controls plans greatly to enhance the system
usability and may be operational, very good has satisfied the scene
production request. At the same time, is improving the field
work environment, improves the product quality, reduced the ton steel
energy consumption aspect to get up the positive role. Third,
system characteristic: The frequency conversion velocity
modulation technology after the electric stove dust removal system the
application, has mainly manifested following several characteristics:
1. dust removal equipment power loss changes the load movement
along with the electric stove steel-making production craft, enhanced
the system efficiency; Has realized the dust removal system best
operating mode movement. Obtains the remarkable energy
conservation effect. 2. greatly effectively reduced the dust
removal system load factor, lengthened the dust remover, has removed
dust the air blower, removes dust the electrical machinery, smoke and
so on the equipment service life. 3. pairs reduce in the stove
the quantity of heat to lose, the reasonable controlled process
temperature, guarantees the outlet temperature to play the certain
role. 4. pair of dust removal systems carry on the frequency
conversion transformation, is helpful to improves in the stove the
blowing operating mode, reduces the steel-making time, enhances the
steel output improvement tapping quality. 5. reduces 补炉 the
period energy consumption and the furnace lining radiation loss.
Fourth, energy conservation analysis:
In order to after removes dust the system frequency conversion
transformation the effect to carry on the appraisal, has carried on
the determination and the data analysis in a system investment normal
operation month to the equipment actual use and the electricity saving
situation.
Stochastically extracts a regular production date, uses the
system cut to the labor frequency movement system the back plate
control adjustment amount of wind. Uses the net side to have the
merit electric meter to carry on the power consumption measurement,
see Table 1. Then, continuously gathers the frequency conversion
movement 7 regular productions everyday use electric quantity to carry
on under the frequency conversion movement operating mode only to
consume the computation, approaches the real movement operating mode
by the time frequency conversion movement data, the concrete data
sampling value see Table 1. Table one
Through to on table primary data processing, may obtain:
Before the dust removal system comparatively transforms after
the frequency conversion transformation, the ton steel dust removal
electricity consumed reduced 17.390kW h. The equipment
electricity saving rate reaches as high as 58.63%, the energy
conservation effect is remarkable. When labor frequency movement
when record curve frequency conversion movement record curve
When interception labor frequency movement builds up
when the one heat of steel dust removal air blower electric current
operating record curve and the frequency conversion movement builds up
the one heat of steel the net side electric current record curve
comparison, may direct-viewing see the air blower electric current to
reduce obviously, the equipment movement operating mode conforms to
the actual production craft need. Fifth, conclusion:
Through to around the Daye special steel group some steel mill
#8 electric stove dust removal system frequency conversion
transformation technical analysis, may see: Applies the
high-pressured frequency conversion velocity modulation technology in
the arc furnace dust removal system not only to the effective
improvement scene production condition, enhances the steel output to
reduce the ton to consume has the vital significance; Moreover
every year may save 2.3 million Yuan about the electrical bill
expenditure. Applies the high-pressured frequency conversion
velocity modulation technology in the arc furnace dust removal system
is entirely accurate.
Reference:
Qiu Shaoqi, wishes Gui Huabian the. electric stove steel-making
principle and craft. Beijing: Metallurgical industry publishing
house, 1,996
Shen Caifang and so on arranges. the arc furnace
steel-making craft and the equipment (2nd edition). Beijing:
Metallurgical industry publishing house, 2,001
High-pressured frequency changer application material
assembly. metallurgy profession: Beijing 利德 China luck
electricity technology limited company, 2,004
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