[ summary of the invention ]
The invention aims to overcome the defects of the prior art and provide a white smoke eliminating device based on smoke condensation and chemical adsorption, which can fully condense and separate out water vapor in smoke by strengthening the full heat exchange between the smoke and a condensing pipe in a circulating fluidized bed, enhance the mixing of the smoke and a chemical water absorbent, remove moisture in the smoke, reduce the absolute moisture content of the smoke and eliminate white smoke.
In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:
a white smoke abatement device based on flue gas condensation and chemisorption, comprising:
the device comprises a circulating fluidized bed reactor, a circulating fluidized bed reactor and a water absorption and drying device, wherein a feed inlet for drying water absorbent is formed in the side surface of the upper part of the circulating fluidized bed reactor, a condensing pipe is arranged in the circulating fluidized bed reactor, and a feed outlet for saturated water absorbent is formed in the bottom of the circulating fluidized bed reactor; the lower part of the circulating fluidized bed reactor is provided with an annular flue gas chamber and an air inlet; a cyclone separator is arranged behind the circulating fluidized bed reactor;
the inside of the condensing pipe is provided with a refrigerant which is used for heat exchange of flue gas in the circulating fluidized bed reactor;
a drying crawler belt is arranged below the feed opening; the drying belt is provided with a smoke-water absorbent heat exchanger for converting the saturated water absorbent into the dry water absorbent; the tail end of the drying crawler is provided with a feeding crawler, and the feeding crawler is used for feeding the dry water absorbent into the feeding hole;
the material return port of the cyclone separator is communicated with the circulating fluidized bed reactor, and the flue gas outlet is connected with a bag-type dust collector.
The invention further improves the following steps:
the flue gas-water absorbent heat exchanger is arranged in an inlet flue of the desulfurizing tower.
The feeding baffle is arranged at the feeding port, and an included angle of 60 degrees is formed between the feeding baffle 14 and the vertical direction.
One end of the condensing pipe is sequentially connected with the air compressor, the condenser and the throttle valve, and the outlet of the throttle valve is connected to the other end of the condensing pipe to form refrigerant circulation.
The outside of the condenser pipe is laid with a ceramic coating, and the inside adopts a material with strong heat conductivity coefficient.
The refrigerant is R134 a.
Compared with the prior art, the invention has the following beneficial effects:
according to the white smoke eliminating device based on smoke condensation and chemical adsorption, the refrigerant with lower gasification temperature flows in the condensation pipe, evaporates and absorbs heat, the low-temperature state of the surface of the condensation pipe is maintained, and the heat dissipation capacity of smoke under the same heat exchange area is increased; the reverse Carnot cycle is utilized to form a closed cycle of heat absorption and heat dissipation of the refrigerant, so that the consumption and investment of the refrigerant are reduced; the chemical water absorbent absorbs the water condensed and separated out from the flue gas in time, and the heat capacity of the gas in the fluidized bed is reduced; by utilizing the advantage of the state that materials in the fluidized bed roll up and down, the chemical water absorbent is in a fluidized state and frequently collides with the condenser pipe, so that a liquid film is prevented from being formed on the surface of the condenser pipe, and the phenomenon that the heat exchange between the flue gas and the surface of the condenser pipe is weakened by film condensation is avoided; the saturated chemical water absorbent after absorbing water exchanges heat with the flue gas before entering the desulfurizing tower, the temperature of the flue gas entering the desulfurizing tower is reduced while the chemical water absorbent is dried, and the moisture carried by the flue gas after entering the desulfurizing tower is reduced; the flue gas is separated from the chemical water absorbent through the cyclone separator, so that the circulation rate of the chemical water absorbent in the fluidized bed is ensured, and the chemical water absorbent is in full contact with the flue gas for multiple times; the broken small-particle water absorbent in the fluidized bed is collected through the bag-type dust collector, so that the water absorbent is prevented from being brought into the atmosphere to form secondary pollution. The advantages enable the invention to be applied to the field of flue gas whitening after the desulfurizing tower, and improve the input-output ratio on the premise of high-efficiency whitening.
[ detailed description ] embodiments
In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments, and are not intended to limit the scope of the present disclosure. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present disclosure. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Various structural schematics according to the disclosed embodiments of the invention are shown in the drawings. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity of presentation. The shapes of various regions, layers and their relative sizes and positional relationships shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, according to actual needs.
In the context of the present disclosure, when a layer/element is referred to as being "on" another layer/element, it can be directly on the other layer/element or intervening layers/elements may be present. In addition, if a layer/element is "on" another layer/element in one orientation, then that layer/element may be "under" the other layer/element when the orientation is reversed.
It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The invention is described in further detail below with reference to the accompanying drawings:
referring to fig. 1, the white smoke eliminating device based on flue gas condensation and chemical adsorption comprises a circulating fluidized bed reactor, wherein a feed inlet 13 for drying a water absorbent is arranged above the circulating fluidized bed reactor, and the water absorbent directly falls into the fluidized bed to contact with flue gas for subsequent reaction; the middle part of the circulating fluidized bed reactor is provided with a condensing tube 10 which provides a low-temperature surface for condensation and separation of water vapor in the flue gas, the flue gas can fully impact and contact with the condensing tube 10, the heat exchange between the flue gas and the condensing tube is enhanced, the condensation and separation of water in the flue gas are promoted, and the separated water is fully contacted with a water absorbent in the circulating fluidized bed reactor to be adsorbed; the water absorbent which rolls up and down is arranged in the circulating fluidized bed reactor and can impact the condensation pipe 10 to remove water drops which can be attached to the surface of the condensation pipe 10, so that the heat exchange of the surface of the condensation pipe 10 is further enhanced; a feed opening 6 for saturated water absorbent is arranged below the fluidized bed reactor, and the water absorbent is discharged after reaching a saturated state; the desulfurized flue gas enters an annular air chamber 7 positioned at the bottom of the fluidized bed and enters the fluidized bed through an air inlet 8 arranged above the annular air chamber 7 to form uniform flue gas flow, and the gas flow velocity passing through the air inlet can enable the water absorbent to reach a fluidized state, so that the flue gas can enter the fluidized bed at a uniform high speed.
Cyclone 12 has been arranged at fluidized bed reactor rear, separates out the water absorbent in the flue gas, prevents that the water absorbent from being taken out to cloth bag dust remover 5 has been arranged at cyclone 12 rear, fully desorbs the water absorbent that carries in the flue gas, further reduces the particulate matter that probably carries in the flue gas, and the flue gas gets into the chimney behind cloth bag dust remover 5, the atmosphere of discharging.
And a drying crawler 3 is arranged below the feed opening 6, the saturated water absorbent falls on the crawler 3 firstly, and moves to the flue gas-water absorbent heat exchanger 1 in the flue along with the crawler, and the water absorbent is heated by utilizing the waste heat of the flue gas, so that the water in the saturated water absorbent is recycled and evaporated, and the saturated water absorbent is further converted into the dry water absorbent. A flue gas-water absorbent heat exchanger 1 is arranged in the inlet flue 2.
The end of the drying crawler 3 is provided with a feeding crawler 16, and the dry water-absorbing agent is carried to the upper part of the feeding baffle 14 through the feeding crawler 16 and enters the circulating fluidized bed through the feeding hole 13.
The feeding baffle 14 is at an angle of 60 degrees to the vertical and ensures a smooth baffle surface, the dry water-absorbing agent can slide down smoothly and will not adhere to the baffle.
The condenser pipe 10 is connected with a compressor 17, a condenser 18 and a throttle valve 19, and a refrigerant flows inside to form a refrigeration cycle, so that heat released by condensation of water in the flue gas is brought into the atmosphere.
The ceramic coating is laid on the outer side of the condensation pipe 10, and the material with strong heat conductivity coefficient is adopted on the inner side, so that the heat exchange is enhanced under the condition that the surface of the condensation pipe is prevented from being corroded.
The refrigerant adopts R134a, the gasification temperature is-20 ℃, the difference with the flue gas temperature is large, and the heat exchange quantity requirement can be met in a small area during heat exchange.
The annular flue gas chamber 7 and the air inlet 8 can uniformly desulfurize flue gas, and the total ventilation area of the air inlet is adjusted according to the total flue gas volume, so that the speed of the flue gas can reach the fluidization speed when the flue gas enters the fluidized bed.
The principle and the working process of the invention are as follows:
the dry water absorbent enters the circulating fluidized bed through the feed port 13, the ratio of the initial water absorbent to the amount of water carried in the flue gas in unit time is controlled to be 3:1, the water absorbent starts to move downwards under the action of gravity, the flow direction of the initial flue gas is opposite, then the water absorbent is in a boiling state under the double action of the flue gas and the gravity, the water absorbent collides with the surface of a condensing pipe 10 arranged in the middle of the fluidized bed for many times to adsorb condensed water formed on the condensing surface, when the water absorbent has enough water absorption capacity and reaches a saturated state, the gravity of the water absorbent mainly plays a role in falling into the discharge port 6, when the water absorbent accumulates to a certain amount, the discharge port 6 is opened, the saturated water accumulation agent falls onto the drying crawler 3, part of the water absorbent is possibly taken out of the circulating fluidized bed under the action of the flue gas, the water absorbent is separated from the flue gas, part of particles which are not completely separated by the cyclone separator 12 enter the bag-type dust collector 5 arranged at the rear part along with the smoke, and the circulating process of the water absorbent outside the circulating fluidized bed is separated from the flowing process of the smoke and does not physically contact with the smoke.
The water absorbent falling on the drying caterpillar 3 enters the smoke-water absorbent heat exchanger 1 through the caterpillar, is heated to 125 ℃ by using the waste heat of the smoke, and the moisture in the water absorbent is fully evaporated at the temperature to form the dry water absorbent. The conveying speed of the drying crawler 3 is equal to the falling speed of the saturated water absorbent, the heat exchange speed of the smoke and the water absorbent is equal to the conveying speed of the drying crawler 3, then the drying water absorbent falls into the feeding crawler 16, and enters the circulating fluidized bed through the feeding hole 13 arranged at the upper right of the circulating fluidized bed under the lifting action of the feeding crawler 16, the feeding speed of the feeding crawler is equal to the drying speed of the water absorbent, and therefore the external circulation subsystem of the water absorbent can be in a quasi-stable dynamic balance process.
The refrigerant R134a with the gasification temperature of-20 ℃ is left in the condensation pipe 10, the flow rate is determined according to the flue gas flow rate and the flue gas moisture content, the refrigerant is gasified in the condensation pipe 10 to maintain the surface of the condensation pipe 10 at-20 ℃, the flue gas and the condensation pipe 10 exchange heat and cool, water in the flue gas is slowly separated due to supersaturation, part of separated water is directly absorbed by the water absorbent in the circulating fluidized bed, and part of separated water is adhered to the surface of the condensation pipe 10, desorbed under the impact action of the water absorbent and further contacted with and absorbed by the water absorbent. The evaporated refrigerant enters the compressor 17 to form high-temperature and high-pressure gas, then enters the condenser 18 to release heat and condense, passes through the throttle valve 19, and finally enters the inside of the condenser pipe to form a refrigeration sub-cycle.
The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.