CN214131067U - Cement plant flue gas dust removal deNOx systems - Google Patents

Abstract

A flue gas dedusting and denitration system for a cement plant belongs to the technical field of flue gas dedusting and denitration. In industry, the flue gas waste heat is often utilized to firstly carry out denitration and then remove dust, so that the service life of the denitration catalyst is short, and the denitration and dust removal effects are poor. And then with greatly increased aftertreatment cost to denitration catalyst heating alone, the utility model discloses utilize dust collector (1), denitrification facility (2) and kiln section of thick bamboo wall waste heat recovery device (3), to the denitration of earlier dust removal of flue gas after, utilize kiln section of thick bamboo wall waste heat recovery device (3) and heating coil to provide the heat source to the catalyst, heat transfer efficiency is higher, the heating is more stable, has prolonged the life of denitrification facility (2) greatly, make full use of the kiln section of thick bamboo wall waste heat of cement plant, the energy saving.

Description

Cement plant flue gas dust removal deNOx systems

Technical Field

A flue gas dedusting and denitration system for a cement plant belongs to the technical field of flue gas dedusting and denitration.

Background

Denitration is a process for removing nitrogen oxides in combustion flue gas, and plays an important role in preventing environmental pollution. At present, dust removal and desulfurization technologies are widely applied, and the removal of nitrogen oxides is greatly restricted only by the limitation of the denitration technology.

At present, the activity temperature of a commercial selective catalytic reduction denitration (SCR) catalyst is 300-400 ℃, in order to utilize the waste heat of flue gas to be treated, the flue gas to be treated is required to pass through the denitration catalyst firstly in industry, the denitration catalyst is heated by the waste heat of the flue gas for denitration, and then the flue gas passes through a dust remover, so that a catalytic plate is easily polluted by impurities, the service life is reduced, the catalyst is easy to sinter and inactivate or generate NH due to high temperature₃Oxidized to NO, etc. Simultaneously, directly utilizing the flue gas waste heat to heat the denitration catalyst, the catalyst temperature directly receives flue gas temperature control, and it can the high temperature to go out, also can appear the temperature and hang down the catalyst activity unsatisfactory excessively, and the denitration is not abundant, leads to the flue gas nitrogen oxygen content after all denitrifications unstable. In addition, materials in the dust removal device sometimes need to be heated at a certain temperature, so that air channels are easy to pass through, smoke dust is not easy to attach to the dust remover, and the smoke carries heat greatly reduced after denitration, so that the dust removal effect is not reasonableWant.

Disclosure of Invention

The utility model discloses the technical problem that will solve is: overcome prior art's not enough, provide a cement plant flue gas dust removal deNOx systems that dust removal denitration effect is all good and stable, longe-lived.

The utility model provides a technical scheme that its technical problem adopted is: the utility model provides a cement plant flue gas dust removal deNOx systems, includes dust collector and denitrification facility, its characterized in that: the device also comprises a kiln cylinder wall waste heat recovery device; the denitration device comprises a shell and a catalytic plate arranged in the shell, wherein the shell is provided with an air inlet and an air outlet, and the catalytic plate is arranged inside the shell; the kiln cylinder wall waste heat recovery device is a heat exchange coil arranged on the outer side of the kiln cylinder wall, and an outlet and an inlet of the heat exchange coil are respectively connected with two ends of the heating coil; the heating coil is arranged on the surface of the catalytic plate.

The flue gas to be treated is dedusted by the dedusting and dedusting device, enters the denitration device for denitration, enters the denitration device from the gas inlet, is denitrated by the catalyst of the catalytic plate and is discharged from the gas inlet; after the kiln cylinder wall waste heat recovery device heats the heat transfer medium, the heat transfer medium is used for transferring heat to the heating coil, the heating coil heats the catalytic plate, and the heat transfer medium is preferably deionized water.

The utility model discloses earlier with the flue gas through flue gas dust collector, utilize the higher waste heat of flue gas to make the flue gas obtain higher passing speed and smoke and dust filtration efficiency, then pass through denitrification facility again, thoroughly give up the heating of flue gas waste heat, but regard as the heat source with kiln wall waste heat to heat transfer medium conducts heat, heats the catalysis board with heating coil, and heat transfer efficiency is higher, and the heating is more stable: the heat transfer medium is used for buffering the residual heat of the kiln cylinder wall in one step, which is equivalent to the specific heat capacity of the heat transfer medium, so that the heat transferred to the catalytic plate is more stable, and the problems that the catalyst is sintered and inactivated at a higher temperature and the like, or the catalyst is insufficient in activity and insufficient in denitration due to too low temperature are avoided; the waste heat of the kiln cylinder wall of the cement plant is fully utilized, and the energy is saved; the flue gas is dedusted and then denitrated, so that the service life of the denitration device is greatly prolonged.

Preferably, the dust removal device include the dust removal shell with inside exhaust fan and the filter equipment of dust removal shell, be equipped with flue gas entry and exhanst gas outlet on the dust removal shell, dust removal device passes through the air inlet of exhanst gas outlet connection denitrification facility, filter equipment preferably cross filter bag and metal picture peg. The flue gas gets into the back from the flue gas entry, filters the smoke and dust through filter equipment, then blows off through exhaust fan and exhanst gas outlet, and the exhaust fan provides filtering pressure for filter equipment, improves filtration efficiency.

Preferably, a vibration motor is arranged on the outer side of the shell of the dust removal device, and a dust collection device is arranged below the filtering device. Can shake off the smoke and dust on the filter equipment through the vibrations motor, easily clear up after falling into dust collection device, prolong dust collector's life.

Preferably, the catalytic plate is a honeycomb catalytic plate. The honeycomb type catalytic plate has larger contact area and flue gas flow area with flue gas, and the denitration efficiency is high; meanwhile, the heating coil pipe has a faster heat conduction rate and a more uniform heating effect.

Preferably, the air inlet is arranged at the upper part of the denitration device, the air outlet is arranged at the side surface of the bottom of the denitration device, and the catalytic plates are provided with a plurality of blocks which are all arranged perpendicular to the air inlet direction. Set up like this and make flue gas top-down denitration to avoid the dust that falls to block up the gas outlet or discharge along with the gas outlet, the catalysis board can be with the biggest windward side to flue gas catalysis denitration simultaneously, improves denitration efficiency and catalysis board utilization ratio.

Preferably, a water feeding pump is arranged between the water inlet of the kiln cylinder wall waste heat recovery device and the water outlet of the heating coil, and a pressure stabilizing and water supplementing device is further arranged between the water feeding pump and the heating coil. The stable pressure moisturizing device cooperates with the water feeding pump to stably control the flow speed and pressure of the heat transfer medium in the kiln cylinder wall waste heat recovery device and the heating coil, so that the phenomenon that the heat received by the catalytic plate is unstable due to unstable flowing speed is avoided, the catalytic effect of the catalytic plate is influenced, the flowing pressure of the heat transfer medium can be increased under the condition that the residual temperature of the kiln cylinder wall is higher, the heat transfer efficiency is improved, and the temperature of the catalytic plate is stably increased.

Preferably, the bottom of the denitration device is a detachable cover plate. The apron that preferably passes through screw or buckle structure is fixed can be dismantled as required to the inside dust that falls of clearance denitrification facility also is convenient for change the inside catalysis board of maintenance.

Preferably, the denitration device further comprises a one-way valve, and the one-way valve is arranged on a pipeline between the denitration device and the dust removal device. The one-way valve prevents the flue gas from flowing backwards when the pressure in the denitration device is too high, and can control the opening and closing of the whole system.

Compared with the prior art, the utility model discloses the beneficial effect who has is: the denitration catalyst has the advantages that the flue gas is dedusted and then denitrated, a catalytic heat source is provided by using the waste heat of the kiln cylinder wall, the dedusting efficiency is improved, the temperature of the denitration catalyst is stable and controllable, the denitration effect is improved, the dedusting and denitration are stable for the flue gas, the service life of the whole system is longer, the flue gas only needs to pass through two devices in the whole process, the structure is simple, the maintenance is easy, the operation is convenient, the energy provided by the required outside is less, the environment is protected, and the energy is saved.

Drawings

FIG. 1 is a schematic view of a flue gas dedusting and denitration system of a cement plant in embodiment 1.

Fig. 2 is a schematic view of a kiln wall waste heat recovery device in embodiment 1.

Fig. 3 is a right side view of the kiln tube wall waste heat recovery device in fig. 2.

FIG. 4 is a top view of the inside of a denitration apparatus according to example 1.

FIG. 5 is a schematic view of a flue gas dedusting and denitration system of a cement plant in embodiment 2.

Wherein, 1 dust collector, 2 denitrification facility, 3 kiln bobbin wall waste heat recovery device, 4 air inlets, 5 catalysis board, 6 gas outlets, 7 heating coil, 8 exhanst gas outlets, 9 exhaust fan, 10 filter equipment, 11 flue gas entry, 12 shock motors, 13 dust collection device, 14 water-feeding pump, 15 steady voltage moisturizing device, 16 check valves, 17 kiln bobbin wall waste heat recovery device delivery ports, 18 kiln bobbin wall waste heat recovery device water inlets, 19 heating coil water inlets, 20 lower floor's heating coil handing-over department.

Detailed Description

The present invention will be further explained with reference to fig. 1 to 5, and fig. 5 is a preferred embodiment of the present invention.

Example 1

Referring to the attached figures 1-4: a cement plant flue gas dedusting and denitration system comprises a dedusting device 1, a denitration device 2 and a kiln cylinder wall waste heat recovery device 3, wherein the dedusting device 1 is connected with a gas inlet 4 of the denitration device 2, the denitration device 2 comprises a shell and a catalytic plate 5, the gas inlet 4, the catalytic plate 5 and a gas outlet 6 are sequentially arranged in the denitration device from top to bottom, the catalytic plate 5 is provided with three honeycomb catalytic plates which are fixed in a direction perpendicular to the gas inlet direction, and the gas outlet 6 is arranged on the side surface of the denitration device 2; the kiln cylinder wall waste heat recovery device 3 is a heat exchange coil arranged on the outer side of the kiln cylinder wall, heat transfer media are respectively shunted from a water inlet 18 of the kiln cylinder wall waste heat recovery device to 4 water inlets to be filled into the serpentine pipeline, carry out heat exchange with radiant heat of the kiln cylinder wall and flow into a water outlet 17 of the kiln cylinder wall waste heat recovery device from the 4 water outlets, so that the serpentine pipeline is divided into four independent serpentine pipes, and the installation and the maintenance are convenient; the water outlet 17 of the kiln wall waste heat recovery device is connected with the water inlet 19 of the heating coil, and the water inlet 18 of the kiln wall waste heat recovery device is connected with the water outlet of the heating coil 7; the heating coil 7 is arranged on the surface of the catalytic board 5 in a coil form, and the heat transfer medium from the kiln wall waste heat recovery device 3 flows into the lower heating coil from the junction 20 of the lower heating coil after passing through the surface of the catalytic board 5 of one layer in the heating coil 7 to heat the lower catalytic board 5. The heat transfer medium is deionized water.

The inside top-down of dust collector 1 has set gradually exhanst gas outlet 8, exhaust fan 9, filter equipment 10 and flue gas entry 11, and dust collector 1 passes through 8 air inlets of connecting denitrification facility 2 of exhanst gas outlet, and the dust collector 1 casing outside is equipped with shock motor 12, and inside bottom is equipped with the dust collection device 13 that dirt fill and dust collection box constitute, and the dirt fill is the infundibulate, connects the dust collection box, and the opening enables the dust to fall into in the dust collection box to filter equipment (10).

After entering from the flue gas inlet 11, flue gas filters smoke dust through the filtering device 10, and then is blown out through the exhaust fan 9 and the flue gas outlet 8, the exhaust fan 9 provides filtering pressure for the filtering device 10, so that the filtering efficiency is improved, and then enters the denitration device 2 for denitration, enters from the gas inlet 4 in the denitration device 2, and is discharged from the gas outlet 6 after being denitrated by the catalyst of the catalytic plate 5; wherein, after the kiln tube wall waste heat recovery device 3 heats the deionized water, the deionized water is utilized to send the heat to the heating coil 7, and the heating coil 7 heats the catalytic plate 5. The deionized water can effectively avoid the corrosion of the inner wall of the pipeline and prolong the service life of the system. And starting the vibration motor 12 every time the dust collector 1 runs for a period of time, shaking off the dust in the dust collector 1 into the dust collector 13, and prolonging the service life of the dust collector 1.

Example 2

Referring to fig. 5: a cement plant flue gas dedusting and denitration system is characterized in that on the basis of embodiment 1, a water feed pump 14 is arranged between a water inlet of a kiln cylinder wall waste heat recovery device 3 and a water outlet of a heating coil 7, and a pressure-stabilizing water supplementing device 15 is further arranged between the water feed pump 14 and the heating coil 7; the bottom of the denitration device 2 is provided with a detachable cover plate; a one-way valve 16 is also arranged on the pipeline between the denitration device 2 and the dust removal device 1.

The pressure in the kiln cylinder wall waste heat recovery device 3 is controlled to be stable through the water feeding pump 14 and the pressure stabilizing and water supplementing device 15, the temperature of the catalytic plate 5 is further controlled to be more stable, and the temperature variation amplitude is reduced; the cover plate can be detached at any time, and accumulated dust in the denitration device 2 is cleaned or the catalytic plate 5 is maintained and replaced; the one-way valve 16 prevents the flue gas from flowing backwards when the pressure in the denitration device is too high, and can control the opening and closing of the whole system.

While the invention has been described with reference to a preferred embodiment, 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. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical substance of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims (8)

1. The utility model provides a cement plant flue gas dust removal deNOx systems, includes dust collector (1) and denitrification facility (2), its characterized in that: the device also comprises a kiln cylinder wall waste heat recovery device (3); the denitration device (2) comprises a shell and a catalytic plate (5) arranged in the shell, wherein the shell is provided with an air inlet (4) and an air outlet (6), and the catalytic plate (5) is arranged inside the shell; the kiln cylinder wall waste heat recovery device (3) is a heat exchange coil arranged on the outer side of the kiln cylinder wall, and an outlet and an inlet of the heat exchange coil are respectively connected with two ends of a heating coil (7); the heating coil (7) is arranged on the surface of the catalytic plate (5).

2. The cement plant flue gas dedusting and denitration system of claim 1, characterized in that: dust collector (1) including dust removal shell with inside exhaust fan (9) of dust removal shell and filter equipment (10), be equipped with flue gas entry (11) and exhanst gas outlet (8) on the dust removal shell, dust collector (1) is through air inlet (4) of exhanst gas outlet (8) connection denitrification facility (2).

3. The cement plant flue gas dedusting and denitration system of claim 2, characterized in that: the dust removal device (1) is characterized in that a vibration motor (12) is arranged on the outer side of a shell, and a dust collection device (13) is arranged below the filtering device (10).

4. The cement plant flue gas dedusting and denitration system of claim 1, characterized in that: the catalytic plate (5) is a honeycomb catalytic plate.

5. The cement plant flue gas dedusting and denitration system of claim 1, characterized in that: the gas inlet (4) is arranged at the upper part of the denitration device (2), the gas outlet (6) is arranged at the side surface of the bottom of the denitration device (2), and the catalytic plate (5) is provided with a plurality of blocks.

6. The cement plant flue gas dedusting and denitration system of claim 1, characterized in that: the kiln barrel wall waste heat recovery device is characterized in that a water feeding pump (14) is arranged between an inlet of the kiln barrel wall waste heat recovery device (3) and the heating coil (7), and a pressure stabilizing and water supplementing device (15) is further arranged between the water feeding pump (14) and the heating coil (7).

7. The cement plant flue gas dedusting and denitration system of claim 1, characterized in that: the bottom of the denitration device (2) is a detachable cover plate.

8. The cement plant flue gas dedusting and denitration system of claim 1, characterized in that: still include check valve (16), check valve (16) set up on the pipeline between denitrification facility (2) and dust collector (1).

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