The blast furnace gas drying bag dust removing system
Technical field
The utility model relates to a kind of dedusting of blast furnace gas system, relates to a kind of blast furnace gas drying bag dust removing system particularly.
Background technology
At smelting industry, the coal gas that blast furnace produces carries a large amount of heats and useful matter on the one hand, has a large amount of dusts on the other hand, and its dust content is up to 40g/m
3, can not directly be discharged into atmosphere.Before discharging, all must carry out purifying treatment.Two kinds of common treatment systems are arranged at present, are respectively wet method dedusting system and dry-dedusting system.Wet method dedusting system mainly washes coal gas with water, to reach the dedusting purpose.The subject matter that wet dedusting exists is running energy consumption cost height, particularly produces the sewage and the mud of a large amount of secondary pollutions.Contain hazardous and noxious substances in this sewage and the mud, its content surpasses emission standard, can not directly discharge or return use, must handle, and will handle, and needs huge facility and higher working cost.Simultaneously, in dust removal process, the pressure of blast furnace gas, temperature all greatly reduce, and cause the loss of energy.
In view of these deficiencies that wet method dedusting system exists, dry method dust more and more becomes the trend of current smelting industry.Most of dry-dedusting systems comprise gravitational precipitator, sack cleaner, reducing valve group and TRT (being that blast furnace furnace roof overbottom pressure reclaims power generation assembly), gravitational precipitator is connected with the blast furnace furnace roof by pipeline, State of Blast Furnace is ejected the raw gas that comes carry out just handling, purpose is the big dust particle in the raw gas to be filtered make raw gas become half purified gas.Gravitational precipitator connects by half clean coal tracheae and sack cleaner (be made up of several fly-ash separator casings, hang with some cloth bags in each casing), through the cloth bag filtration, makes half purified gas become purified gas.The outlet of sack cleaner is responsible for by coal gas and is connected with TRT with the reducing valve group respectively, by importing dry method heating gas house steward again after reducing valve group and the TRT shunt.Dry method heating gas house steward is provided with some branch roads, is connected with user's (as converter, boiler etc.) respectively, uses for the user.
Dry-dedusting system has overcome wet dedusting institute inherent defective because of water not, and the blast furnace gas sensible heat is increased substantially, reduce the pressure-losses and working cost, has avoided washing to take with generation sewage and the huge treatment facility and the place of bringing thus.Although its advantage is a lot, still exist not enough.From the introduction of above-mentioned dry-dedusting system as can be seen, gravitational precipitator directly is connected with sack cleaner by half clean coal tracheae, and owing to the reason of blast furnace, its temperature and pressure of half purified gas that comes out from gravitational precipitator can not be in steady state always, fluctuation might occur, especially temperature is lower in blow-on just, often is lower than 85 ℃, and when breaking down, temperature might be very high.The appearance of these situations, all very unfavorable to sack cleaner, because the temperature of general its works better of sack cleaner is 100---260 ℃, its maximum operating temperature is no more than 300 ℃.Temperature is too high, and the cloth bag filtrate will instantaneously burn, and must change, and causes blast furnace staying; And if low excessively, when being lower than 90 ℃, the cloth bag filtrate will make in the coal gas saturated water vapour separate out with dust and be bonded together, thereby form so-called " sticking with paste bag " phenomenon, make half purified gas (being raw gas) can not pass through cloth bag, cause blast furnace to be forced to stop production.In case sack cleaner needs repairing, blast furnace will be forced to damping down and cooperate handling failure, influence dust removing effects and ordinary production.
The utility model content
Exist the deficiency that sack cleaner may burn or " sticking with paste bag " stops up at existing dry-dedusting system; the purpose of this utility model just provides a kind of novel blast furnace gas drying bag dust removing system; it is the protecting cloth bag dust collector effectively, avoids occurring burning or " sticking with paste bag " phenomenon.
The purpose of this utility model is achieved in that the blast furnace gas drying bag dust removing system, comprise gravitational precipitator, sack cleaner, the input terminus of gravitational precipitator is connected with blast furnace by the rash tracheae, the output terminal of gravitational precipitator is connected with the input terminus of sack cleaner by half clean coal tracheae, is provided with reducing valve group and TRT in parallel between the output terminal of sack cleaner and dry method heating gas house steward.Its improvements are: be provided with temperature sensor in half clean coal tracheae, between temperature sensor and sack cleaner, be provided with the overtemperature corresponding and diffuse branch road with temperature sensor, the termination that overtemperature diffuses branch road with diffuse tower and be connected, overtemperature diffuses half clean coal tracheae between branch road and the sack cleaner and overtemperature and diffuses and be equipped with valve on the branch road.
Further improve being, the spraying cooling device is arranged being positioned at the half clean coal tracheae peripheral hardware that gravitational precipitator to overtemperature diffuses this section of branch road.Carry out spraying cooling by outer tube wall and handle, can make half purified gas that is in the overtemperature operating mode that the process of a preliminary cooling is arranged this section half clean coal tracheae.
Further improve and be, in dry method heating gas house steward, be provided with pressure transmitter, be provided with the step-down branch road corresponding with pressure transmitter on the dry method heating gas house steward of pressure transmitter back segment being positioned at, the step-down branch road is provided with valve, and they are advisable to be located at the dry method heating gas house steward section of beginning.Described back segment is specified by the coal gas flow path direction, and coal gas is toward leading portion stream, and what flow through is back segment.By the purified gas in the dry method heating gas house steward is carried out pressure monitoring, if pressure surpasses default higher limit, then open the step-down branch road and carry out step-down by the step-down branch road, purified gas pressure in the dry method heating gas house steward is remained in the preset value, guarantee that thus dry method heating gas house steward can not make its destruction because of hypertonia.
Adopt the utility model, move towards owing to half purified gas that comes out from gravitational precipitator has two-way, the one tunnel is the same with prior art, leads to the sack cleaner dedusting, and the overtemperature of leading up to diffuses branch road and leads to tower burning and exhausting or direct discharging of diffusing.When temperature sensor monitors is in greater than 260 ℃ overtemperature operating mode or during less than 100 ℃ worst cold case to half purified gas that comes out from gravitational precipitator, half clean coal is made that overtemperature diffuses branch road leave with rage and without dust removal process, is led to and diffuse tower burning or directly discharging.When temperature returns to standard state, just by sack cleaner dust collecting process dedusting routinely.Guaranteed that thus the gas temperature that enters sack cleaner can not cause bad damage to cloth bag, avoided cloth bag Yin Gaowen and burn or because of the appearance of low temperature " stick with paste bag " stopping state.
In addition, before the shunt of half purified gas, carry out spraying cooling by double clean coal tracheae of the spraying cooling device outer tube wall that is provided with, make half purified gas that is in the overtemperature operating mode that the process of a preliminary cooling be arranged, reduced by half purified gas by diffusing the possibility of tower discharging, correspondingly reduced the loss of gas pressure.The setting of step-down branch road has guaranteed that dry method heating gas house steward can not make its destruction because of hypertonia.
This blast furnace gas drying bag dust removing system drops into to increase on the basis of original dust-removal system and lacks, and is simple, is convenient to grasp and control, and it is in time convenient to regulate.
Description of drawings
Fig. 1 is a structural representation of the present utility model, and arrow is represented the coal gas trend.
Embodiment
The utility model is described in further detail below in conjunction with accompanying drawing.
Referring to Fig. 1, as can be seen, the utility model blast furnace gas drying bag dust removing system comprises gravitational precipitator 1, sack cleaner 2 from the figure.Gravitational precipitator 1 of the present utility model and sack cleaner 2 are prior art, and wherein the sack cleaner model is CGMC10-4700, are made up of 10 fly-ash separator casings, hang with 192 cloth bags in each casing, and the cloth bag specification is φ 130 * 6000.Cloth bag select for use fluorine beautiful this as filter cloth, it has advantages such as high temperature resistant, high strength, antiacid caustic corrosion, wear-resisting, anti-folding.The input terminus of gravitational precipitator 1 is connected with blast furnace 4 by rash tracheae 3.In the prior art, blast furnace 4 furnace roofs generally are provided with the raw gas passage of three parallel connections, and at the blow-on initial stage, the coal gas amount is little, and pressure and temperature is all not too even, and only open a main channel this moment, in addition two standby.After blast furnace 4 operations are normal, again two alternate channels are opened, enter three standard states of working simultaneously.The output terminal of gravitational precipitator 1 is connected with the input terminus of sack cleaner 2 by half clean coal tracheae 5, and 6 of the output terminal of sack cleaner 2 and dry method heating gas house stewards are provided with reducing valve group 7 and TRT8 in parallel.In half clean coal tracheae 5, be provided with temperature sensor 9, between temperature sensor 9 and sack cleaner 2, be provided with the overtemperature that corresponding with temperature sensor 9 half purified gas that is used for temperature exceeding standard diffuses and diffuse branch road 10.The termination that overtemperature diffuses branch road 10 with diffuse tower 11 and be connected, overtemperature diffuses half clean coal tracheae 5 between branch road 10 and the sack cleaner 2 and overtemperature and diffuses and be equipped with valve 12 on the branch road 10.If half purified gas temperature exceeding standard then will be closed towards the valve 12 of half clean coal tracheae 5 of sack cleaner 2, open the valve 12 that overtemperature diffuses branch road 10, half purified gas is introduced overtemperature diffuse branch road 10 and enter and diffuse tower 11 burnings or directly discharging.If half purified gas temperature meets the requirements, do not exceed standard, just it is fed sack cleaner 2 dust removal and filtrations.By diffusing the setting of branch road, can avoid half too high and low excessively purified gas of temperature to enter sack cleaner, guaranteed that cloth bag is not burnt or " sticking with paste bag ".
In order to make half purified gas that is in the overtemperature operating mode that the process of a preliminary cooling be arranged, the utility model is provided with spraying cooling device 13 being positioned at outside the half clean coal tracheae 5 that gravitational precipitator 1 to overtemperature diffuses branch road 10 these sections, carry out spraying cooling by outer tube wall and handle, half purified gas temperature of overtemperature operating mode can will be got off this section half clean coal tracheae.Do not meet the requirements if temperature does not still drop to, diffuse branch road 10 by overtemperature so again and diffuse processing, the half purified gas temperature that has further guaranteed to enter sack cleaner 2 is satisfactory, is equivalent to be provided with the twice insurance.For it is perfectly safe to accomplish, can two temperature sensors be set in half clean coal tracheae, be positioned at two places of appropriate intervals, have only half purified gas temperature all to meet the requirements when two places, just can enter sack cleaner, diffuse the branch road discharging otherwise enter overtemperature.
Because entering dry method heating gas house steward 6 purified gas pressure may be very high, hypertonia, there is ruined danger in dry method heating gas house steward 6, therefore, present embodiment is provided with pressure transmitter 14 in dry method heating gas house steward 6, on the dry method heating gas house steward 6 who is positioned at pressure transmitter 14 back segments, be provided with the step-down branch road 15 corresponding, be provided with valve 12 on the step-down branch road 15 equally with pressure transmitter 14.By the purified gas in the dry method heating gas house steward 6 is carried out pressure monitoring, if pressure surpasses default higher limit (higher limit of present embodiment is made as 16kPa), the valve 12 of then opening step-down branch road 15 carries out step-down by step-down branch road 15, purified gas pressure in the dry method heating gas house steward 6 is remained in the preset value, guarantee that thus dry method heating gas house steward 6 can not destroyed because of hypertonia, also guaranteed to be sent to user 16 safely and reliably.
For the ease of operation, guarantee the reliability of system works, above-mentioned temperature sensor all is connected with the operator's console of far-end with pressure transmitter, by the operation to the various buttons of operator's console, finishes unlatching, the closure of various valves and the degree of opening, and realizes remote control.
Principle of work of the present utility model and coal gas trend are:
At first, ejecting the raw gas that comes from State of Blast Furnace just makes it become half purified gas after the processing by gravitational precipitator to the big dust particle that wherein contains.By this processing, generally the thick dirt more than 100 μ can be got rid of.
If be in overtemperature operating mode (temperature is greater than 300 ℃) or worst cold case (temperature is less than 90 ℃) after half purified gas of handling by the last step enters half clean coal tracheae, then be introduced into overtemperature and diffuse branch road and enter and diffuse tower burning or directly discharging; If temperature meets the requirements, just it is fed the sack cleaner dust removal and filtration.
After half purified gas after sack cleaner is handled becomes purified gas and comes out, entering coal gas is responsible for, this moment, coal gas divided two-way, and one the tunnel through reducing valve group remittance dry method heating gas house steward, and one the tunnel imports dry method heating gas house steward after TRT (blast furnace furnace roof overbottom pressure reclaims power generation assembly) generating.If the purified gas pressure in the dry method heating gas house steward exceeds standard, the valve of then opening on the step-down branch road imports the step-down of step-down branch road with the part purified gas, and import volume can pass through valve regulated, till the purified gas pressure in dry method heating gas house steward meets the requirements.
At last, send the user to use the coal gas in the dry method heating gas house steward, these users comprise converter, boiler etc.