Device and method for preventing lime milk of smelting desulfurization system from scaling
Technical Field
The invention belongs to the field of non-standard equipment for preventing scaling of lime milk by treating three wastes in smelting, and relates to a device and a method for preventing scaling of lime milk in a smelting desulfurization system.
Background
In the treatment process of three wastes (waste gas, waste water and waste residue) in smelting, circulating lime milk used by a DS multi-item reactor contains a large amount of iron powder (the lime milk is prepared by ball milling), the lime milk reacts with flue gas to form calcium carbonate precipitate, the lime milk enters a primary pulp tank and an aeration tank in the circulating process, the lime waste liquid and the waste residue need to be detected and pumped regularly manually, a large amount of lime milk blocks are easy to bond in the primary pulp tank, the aeration tank and a DS tower section, the cleaning is difficult after the lime milk blocks are solidified, and the normal treatment of the flue gas is influenced. Waste water, waste gas and waste residue in the three wastes contain a large amount of harmful substances such as arsenic, lead, mercury, sulfur dioxide and the like, so that occupational hazards are easily caused by manual operation, and how to prevent lime milk from scaling is a technical problem of the three-waste smelting treatment process.
Disclosure of Invention
Aiming at the defects of lime slurry treatment of the traditional DS multi-reactor, the invention provides a device and a method for preventing lime milk of a smelting desulfurization system from scaling, the invention realizes automatic slag discharge and cyclic utilization of the lime milk of the DS multi-reactor, and solves the phenomenon that a large amount of lime milk is bonded in a primary pulp tank, an aeration tank and a DS tower section.
The invention is realized by adopting the following technical scheme:
the device for preventing lime milk of the smelting desulfurization system from scaling comprises a primary slurry tank, an aeration tank, a first reaction tower and a second reaction tower, wherein a lime milk outlet of the first reaction tower is connected with a liquid inlet of a first lime chute, a lime milk outlet of the second reaction tower is connected with a liquid inlet of a second lime chute, a liquid outlet of the first lime chute is respectively connected with the aeration tank and a tailing tank inlet through a first lime liquid flow dividing valve, a liquid outlet of the second lime chute is respectively connected with the primary slurry tank and the first lime chute through a second lime liquid flow dividing valve, the aeration tank is connected with a lime milk inlet of the first reaction tower through a first slurry pump pipeline and a first slurry pump pipeline, and the primary slurry tank is connected with a lime milk inlet of the second reaction tower through a second slurry pump pipeline and a second slurry pump. Because the lime emulsion used in the waste gas desulfurization process contains a large amount of iron powder (the iron powder is generated in the process of grinding lime emulsion), and the chemical formula of flue gas treated by the lime emulsion is SO2+ Ca (OH)2 ═ CaSO3+ H2O), wherein CaSO3 is precipitate, and the iron powder and the precipitate can not be discharged from the desulfurization treatment system in time and are easy to deposit on the bottom of the tank, SO that scale can be deposited in the stock slurry tank, the aeration tank and the DS tower section and are high in hardness and extremely difficult to clean, the lime emulsion can be controlled to flow between the stock slurry tank and the aeration tank by adopting the structure through the first lime liquid shunt valve and the second lime liquid shunt valve, the precipitates can be discharged in time, and the lime emulsion in the stock slurry tank and the aeration tank can be recycled by the first slurry pump and the second slurry pump, SO that the problem of scale deposition of the lime emulsion in the stock slurry tank, the aeration tank and the DS tower section is solved, ensures high utilization rate of the lime emulsion.
And the bottom of the raw pulp tank and the bottom of the aeration tank are both provided with a stirrer.
The first lime liquid shunt valve and the second lime liquid shunt valve are connected with a first PH value automatic detection device and a second PH value automatic detection device which are arranged in the aeration tank and the primary pulp tank through a PLC. The system is characterized in that a first water level monitor and a second water level monitor are arranged in the aeration tank and the primary pulp tank respectively, the first water level monitor and the second water level monitor are connected with a lime liquid flow divider valve through a PLC, a primary pulp feeding valve is installed on a feeding pipe of the primary pulp tank, and the primary pulp feeding valve is connected with the PLC. Through first PH value automatic checkout device, second PH value automatic checkout device, first water level monitor and second water level monitor the data of lime cream in former thick liquid pond and the aeration tank respectively, simultaneously feed back the signal to PLC, again through PLC control first lime wash flow divider, second lime wash flow divider and magma feed valve, thereby realized lime cream automatic row's sediment and cyclic utilization, the manual work has been practiced thrift greatly, workman and waste water have been reduced, waste gas, a large amount of arsenic in the waste residue, lead, mercury, harmful substance contact such as sulfur dioxide, workman's safety has been guaranteed, the efficiency of whole control has been improved simultaneously, regularly the drainage, arrange the sediment, lime cream has been solved at the magma pond, the aeration tank, DS tower section deposit scale deposit problem, manufacturing cost has been practiced thrift greatly.
A method for preventing lime milk of a smelting desulfurization system from scaling comprises the following steps:
when the first automatic PH value detection device detects that the PH value in the aeration tank is lower than 6, controlling a first lime liquid flow dividing valve to communicate a first lime chute with an inlet of a tailing pond, and discharging lime emulsion which does not reach the standard into the tailing pond; when the first PH value automatic detection device detects that the PH value in the aeration tank is higher than 6, controlling a first lime liquid flow dividing valve to communicate a first lime chute with the aeration tank;
when the second PH value automatic detection device detects that the PH value in the raw pulp tank is lower than 11, the second lime liquid shunt valve is started, the second lime chute is controlled to be communicated with the first lime chute, the lime raw pulp which does not reach the standard is discharged into the aeration tank, and the raw pulp feed valve is controlled to be opened to feed; when the second automatic PH value detection device detects that the PH value in the primary pulp pool is higher than 11, controlling a second lime liquid flow dividing valve to communicate a second lime chute with the primary pulp pool;
when the first water level monitor detects that the water level of the aeration tank exceeds a set upper limit, controlling a first lime liquid shunt valve to start, controlling a first lime chute to be communicated with an inlet of a tailing tank until the water level of the aeration tank is below a set value and the PH value is greater than 6, and controlling the first lime chute to be communicated with the aeration tank by the first lime liquid shunt valve;
when the second water level monitor detects that the water level of the primary pulp pool exceeds the set upper limit, the primary pulp feeding valve of the primary pulp pool is closed, feeding is stopped, meanwhile, the second lime liquid diversion valve is started, the second lime chute is controlled to be communicated with the first lime chute until the water level of the primary pulp pool is below the set value, the PH value is larger than 11, and the second lime liquid diversion valve controls the second lime chute to be communicated with the primary pulp pool.
In conclusion, the invention realizes the timed drainage and slag discharge of lime milk in the DS multi-reactor, solves the problems of lime milk deposition and scaling in the primary pulp tank, the aeration tank and the DS tower section, the problem of low utilization rate of lime milk, the problem of production cost, the problem of environmental pollution and the problem of occupational hazard, and greatly improves the economic benefit.
Drawings
Fig. 1 is a front view of the present device.
Fig. 2 is a top view of the present device.
Detailed Description
The following describes a specific implementation method of a device for preventing lime milk from scaling in a smelting desulfurization system with reference to the accompanying drawings.
The utility model provides a prevent to smelt device of desulfurization system lime breast scale deposit, includes former thick liquid pond 1, aeration tank 2, mixer 3, slurry pump 4, first slurry pump pipeline 5, second slurry pump pipeline 6, first lime chute 7, second lime chute 8, first lime liquid flow divider 9, second lime liquid flow divider 10, first pH value automatic checkout device 11, second pH value automatic checkout device 12, first water level monitor 13, second water level monitor 14.
The first slurry pump 41 pumps the lime milk in the aeration tank 2 to the first reaction tower 15 of the DS multi-reactor through a first slurry pump pipeline 5, and the lime milk is circulated from a first lime chute 7 at the bottom of the tower to the aeration tank after the spraying reaction.
And a second slurry pump 42 is arranged at the bottom of the raw slurry pool 1, the second slurry pump 42 pumps the lime slurry in the raw slurry pool to the second reaction tower 16 of the DS multi-phase reactor through a second slurry pump pipeline 6, and the lime slurry circularly enters the raw slurry pool 1 from a second lime chute 8 at the bottom of the tower after the spraying reaction.
The first lime chute 7 is connected with a first lime floating flow divider 9, the first lime liquid flow divider 9 is connected with a first PH value automatic detection device 11, the first PH value automatic detection device 11 is installed in the aeration tank 2, the device can automatically detect the PH value in the aeration tank, when the PH value is lower than 6, the first lime liquid flow divider 9 is started, and accumulated waste residues such as non-standard lime emulsion, calcium carbonate and iron powder can be automatically discharged from a circulating system to enter a tailing tank 17.
The second lime chute 8 is connected with a second lime liquid shunt valve 10, the second lime liquid shunt valve 9 is connected with a second PH value automatic detection device 12, the second PH value automatic detection device 12 is installed in the original slurry tank 1, the device can automatically detect the PH value in the original slurry tank, when the PH value is lower than 11, the second lime liquid shunt valve 10 is started, and accumulated non-standard lime emulsion, calcium carbonate, iron powder and the like can be automatically discharged to the first lime chute 7 and enter the aeration tank 2.
The water level is controlled and fed back to the first lime liquid shunt valve 9 through the first water level monitor 13, when the water level of the aeration tank 1 is too high, the first lime liquid shunt valve 9 is started, the water level is controlled and fed back to the raw pulp feeding control valve 18 through the second water level monitor 14, and when the water level of the raw pulp tank 1 is too high, the raw pulp feeding valve 18 is closed and feeding is stopped. The raw pulp feeding amount of the raw pulp tank 1 is matched with the discharge amounts of the raw pulp tank and the aeration tank, and automatic slag and liquid discharge is realized.
The lime chute and the inlet pipe of the slurry pump are used for discharging and pumping slurry at multiple points, and the bottom of the tank is provided with a slope, so that the phenomenon that metal iron powder and lime milk are agglomerated at the bottom can be avoided.
While the preferred embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.