One, cool heat technique prepares silica brick hot-blast stove
According to producing need silica brick hot-blast stove should undertake cool furnace is operated. Leftover quartz is inside silica brick in crystal transition, its coefficient of expansion is bigger, the strength that causes silica brick is weakened, put in bigger risk. Hot-blast stove drops in temperature body of build by laying bricks or stones of unreasonable easy also attaint, affect hot-blast stove service life, accordingly, of hot-blast stove drop in temperature to the curve make reach drop in temperature speed all should be controlled strictly.
Hot-blast stove cool furnace prepares the job to be:
(1) hot-blast stove does not allow construction to work during cool furnace. During be like hot-blast stove cool furnace, inside blast furnace constant somebody construction, hot-blast stove and blast furnace do complete partition, block iron plate or bricklaying up in place of bend of blast furnace a place with a draught namely, prevent burned-out roof equipment.
(2) supports combustion twice fan and cool furnace are used small support combustion fan installation reachs the designated position, achieve manufacturing demand.
(3) each plan implement it is normal that appearance and demonstrative signal move, especially discharge of vault temperature, waste gas temperature, combustion air assures accurate and reliable. Roof measures lukewarm couple instead 900 ℃ of 0 ～ .
(System of 4) hot-blast stove each valve action is quick reliable, limit is correct, test-drive of personal computer control and linkage of hydraulic pressure system, chain ends, reach design requirement level, have normal production requirement.
(5) communication and illume establishment are complete.
(Kong Feng of everybody of system of 6) hot-blast stove is shut.
(Each platform safety, unobstructed is reached all round 7) hot-blast stove.
(Double preheater construction ends 8) , experiment of cold conditions air-tightness, qualification trying leakage, and gas make combustion oven. If construction did not end, bypass pipe construction is finished, block blind board up to cut off double intake air heater thoroughly.
(All sorts of tools that 9) prepares cool furnace to use, material and post operation record and chart.
(10) work out is very cool furnace regulations, organize concerned staff study.
Preparative work demand is sufficient, strict, overall.
2, silica brick hot-blast stove is cool furnace operates measure
Hot-blast stove noumenon drops in temperature use 3 to undertake at the same time. Hot-blast stove drops in temperature use 3 level different technological process undertakes to hot-blast stove system slow drop in temperature cool furnace.
(Phase of 1) front row: Hot-blast stove initial stage uses hot-blast stove to support combustion fan cool furnace, go to vault thermal drop 900 ℃ , temperature of control waste gas does not exceed 400 ℃ . Its technological process is:
Support combustion air of fan air control valve cuts off chimney of a powerful person of flue of hot-blast stove of a powerful person.
(2) the 2nd phase: The cool furnace metaphase of hot-blast stove uses blast furnace air-blower to regard wind as the source, its technological process is:
(3) the 3rd phase: Later period of hot-blast stove cool furnace uses hot-blast stove to support combustion fan regards wind as the source, its technological process is:
Support combustion manager of sirocco of a powerful person of sirocco of exit of sirocco of vault of hot-blast stove of checker brick of regenerator of control valve of air of fan furnace grate, burner flows backwards a powerful person emits into atmosphere.
3, how to consider silica brick hot-blast stove the bulk of the silica brick when cool furnace changes
Rise in body of hot-blast stove build by laying bricks or stones drop in temperature in the process, the bulk change of silica brick is the key of the consideration. Silica brick by scale quartz (80 ％ of 50 ％ ～ ) , Fang Shiying (30 ％ of 20 ％ ～ ) , quartz (10 ％ of 5 ％ ～ ) and a few composition of vitreous photograph place. Outside eliminating vitreous phase, 3 kinds of afore-mentioned quartz the bulk change when crystal brilliant change is distinct.
As a result of silica brick each crystal follows the reversibility that temperature changes, silica brick hot-blast stove is cool furnace becomes a possibility. The working temperature of area of silica brick of blast furnace hot-blast stove is in 13500 ℃ of 850 ～ . The main and chemical composition of silica brick is SiO2, fall in different temperature with different brilliant existence. Firing hind the main and mineral composition of silica brick is - scale quartz, - Fang Shiying reachs a few remains - quartz. Of scale quartz, , aberrant change temperature to be in 163 ℃ of 117 ～ , change of the bulk when changing is in 0.28 ％ of 0.2 ％ ～ ; Of square quartz, aberrant change temperature to be in 270 ℃ of 180 ～ , change of the bulk when changing is controlled in 2.8 ％ ; Of quartz, aberrant change temperature to be in 573 ℃ , change of the bulk when changing is in 0.82 ％ . As a result of the characteristic that the bulk when silica brick photograph changes changes, accordingly, cool furnace should make silica brick hot-blast stove severe cool heat drops in temperature curve.
4, drop in temperature what does note of cool furnace operation have
(Before 1) cool furnace is operated, hot-blast stove burns furnace no longer, fall roof temperature by 1350 ℃ gradually 900 ℃ .
(2) is in cool furnace period ask should drop in temperature strictly by cool furnace curve, can use the bulk that moves wind force and blast furnace vent valve open degree of total plan that will control cool furnace; Of the cold air-valve that uses each hot-blast stove leave to spend and flow backwards of a powerful person degree will adjust of each hot-blast stove drop in temperature speed.
(3) presses a regulation in vault when cool furnace curve drops in temperature ceaselessly, want special attention silica brick and clay brick (or tall aluminous brick) the temperature of face of have a common boundary changes, if the poor value with roof temperature is too great, can reduce hot-blast stove appropriately cool furnace speed and when raising constant temperature, ask.
(4) vault temperature is controlled. If temperature is too high, increase empty tolerance.
(Force of 5) furnace internal pressure is controlled. In drop in temperature in the process, what 98.06Pa should maintain inside furnace is tiny pressing, support combustion with preventing to divide the air beyond the air that fan offers is entered, and bring about the total empty throughput inside furnace to be controlled not easily, in order to get this one tiny pressing, want a powerful person of watchful adjustment flue leave degree, but the valve that notices to have a side of test point of waste gas temperature cannot close completely, in order to assure the accuracy of data of waste gas temperature.
(6) vault temperature is when 573 ℃ , the quartz that silica brick exists changes to expand with bulk, and when 500 ℃ are the following, change to expand with bulk phenomenal aggravate, want special attention to drop in temperature in this phase so speed, those who prevent temperature is acuteness and fluctuant and destroy system of silica brick build by laying bricks or stones (control is in) of 2 ℃ less than, achieve when the temperature inside furnace when 200 ℃ are the following, can consider stew furnace nature to drop in temperature.
5, cool furnace operation has silica brick hot-blast stove He Te is nodded
The cool furnace of silica brick hot-blast stove: Silica brick has good high temperature capability and low temperature (600 ℃ are the following) instability. In the past, once silica brick hot-blast stove throws production, cannot drop in temperature again 600 ℃ are the following, because silica brick contracts suddenly,meet otherwise, create system of silica brick build by laying bricks or stones;burst;ulcerate;fester to defeat and collapse. Domestic and international many experiment considers to discover, the cool furnace of silica brick hot-blast stove, substantially has two kinds of methods.
(1) nature is slow cool furnace.
(2) is fast cool furnace. Silica brick hot-blast stove uses nature slow cool furnace is a success, but the relation as a result of time limit for a project, natural delay is cold have not enough time, do even fast the attempt of cool furnace.
(3) cool furnace operates:
1) stops furnace sky in blast furnace during makings line, hot-blast stove burns furnace no longer, fall roof temperature by L350 ％ gradually 900 ℃ .
2) blast furnace stops furnace to rest after wind, the technological process that uses blast furnace to send wind (watchful hot air-valve does not open) , the air cooling of will other blast furnace dials hot-blast stove, from burner of pottery and porcelain manhole is discharged.
3) should press cool furnace curve strictly to drop in temperature during cool furnace, can use the bulk that moves wind force and a powerful person of blast furnace diffuse open degree of total plan that will control cool furnace; Of the cold air-valve that uses each hot-blast stove spend and the open of exhaust valve Kong Gai is spent will adjust the drop in temperaturing of each hot-blast stove speed.
4) presses a regulation in vault when cool furnace curve drops in temperature ceaselessly, want special attention silica brick and clay brick (or tall aluminous brick) the temperature of face of have a common boundary changes, if the poor value with roof temperature is too great, can reduce hot-blast stove appropriately cool furnace speed and increase constant temperature time.
Get Price
WhatsApp