Reduce the device of wet process of FGD water consumption
Technical field
The utility model belongs to the energy-saving and emission-reduction field, relates to the device that reduces the wet method fume desulfurizing system water consumption in a kind of large-scale power station.
Background technology
China is SO
2Discharging big country is in order to reduce SO
2Pollute, flue gas desulfurization technique has been adopted in a lot of thermal power plants.In various sulfur removal technologies, wet process of FGD (being called for short FGD) is used the most extensive, and construction cost is low, and desulfuration efficiency is high.But it is big that its shortcoming is a water consumption; Along with the continuous popularization of Air-cooled Unit and the widespread usage of pneumatic ash handling technology; Main system of power plant reduces with other accessory system water consumptions greatly; The ratio that the wet desulphurization water consumption accounts for power plant's total water amount increases, and becomes the key factor of the full power plant water amount height of decision.
Wet process of FGD (FGD) system water comprises that mainly being brought into the water, crystal water of gypsum, the desulfurizer that are brought in the atmosphere with liquid form in the water (evaporation water in the tower) in the atmosphere, the wet saturated flue gas with the steam state form in lime stone pulping system water, demister wash water, vacuum belt dewaterer wash water, the wet saturated flue gas discharges aspects such as waste water.Wherein, maximum water consumption point is an evaporated water in the desulfurizing tower, accounts for about 90% of whole desulphurization system water consumption.Under the normal condition; Steam quality mark in the boiler smoke is 8%-10%, at this moment, does not reach its saturation state (state that exhaust gas temperature and pressure thereof are corresponding); But through the flue gas behind the desulphurization reaction of absorption tower, (general liquid-gas ratio is 10-14L/Nm after the countercurrent washing of lime stone slurry
3), water vapor concentration generally is in saturation state, has carried moisture evaporated in a large amount of towers, and this part water enters atmosphere after passing through the absorption tower demisting device with boiler smoke, can not reclaim use.The size of evaporated water has determined the height of the water consumption of whole desulfurizer, and it accounts for the 1/6-1/10 of entire power plant water consumption (Air-cooled Unit).Therefore, to take away the gaseous state water yield be one of main factor of decision full factory (Air-cooled Unit) water consumption level to the clean flue gas of wet process of FGD (FGD) device.
It is thus clear that the key point of the water saving of wet method fume desulfurizing system is to reduce flue gas to take away moisture.Part power plant adopts flue gas heat exchange device (GGH) to reduce the desulfurizing tower entrance flue gas temperature, can reduce the water yield of evaporation loss, but flue gas heat exchange device (GGH) is installed shortcomings such as easy burn into energy consumption increase is arranged also.Therefore, seeking a kind of simple relatively method reduces and realizes that wet process of FGD (FGD) water saving is significant.
The utility model content
The technical problem that the utility model solved is to provide that a kind of cost is lower, the device of the reduction wet process of FGD water consumption of easy realization.
The technical scheme of the utility model is: a kind of device that reduces the wet process of FGD water consumption; It comprises the loop slurry spraying layer; This loop slurry spraying layer top is provided with demister; The fresh water (FW) conveyance conduit connects demister, between demister and loop slurry spraying layer atomizer is set, and this atomizer connects supply channel.
Wherein, this fresh water (FW) transfer pipeline sets up supply channel separately.
This supply channel is provided with valve.
This atomizer is near demister.
The utlity model has following advantage.
There is the large quantity of moisture evaporation to be taken in the atmosphere in the wet fuel gas desulfurizing technology, can't recycles by flue gas.This method can effectively reduce evaporated water in the absorption tower, reduces whole wet process of FGD (FGD) system water consumption.
(1) simple, the realization easily of device.This method need not be done bigger change to the existing wet method fume desulfurizing system of power plant, only need to increase and arrange that an atomizing spray layer and respective line get final product, so cost of investment is low, realizes easily.
(2) operating cost is low.The atomizing water directly comes from fresh water (FW), and spray is equivalent to replenish the required fresh water (FW) of desulfurization in tower, does not need extra increase water consumption, and it is simple to add structure, be not easy to break down, so operating cost is very low.
(3) can reduce the desulphurization system water consumption by a relatively large margin, after experiment proof atomizing effect improved, desulphurization system can reduce 10% ~ 20% because of the water yield that evaporation consumes.
Description of drawings
Fig. 1 is the structural representation of the utility model.
The specific embodiment
As shown in Figure 1; A kind of device that reduces the wet process of FGD water consumption of the utility model; It comprises loop slurry spraying layer 1, and this loop slurry spraying layer 1 top is provided with demister 3, and fresh water (FW) conveyance conduit 6 connects demister 3; 1 of demister 3 and loop slurry spraying layer are provided with atomizer 2, and this atomizer 2 connects supply channel 4.4 pairs of atomizers 2 of supply channel supply water.Wherein, in the present embodiment, this fresh water (FW) transfer pipeline 6 sets up supply channel 4 separately, and the atomizing spray of atomizer 2 directly comes from fresh water (FW), and is provided with valve 5 at supply channel 4, with control flow size.This atomizer 2 does not influence the sweetening process of absorber portion near the below of demister 3.
The operation principle of the utility model is following.
Can improve the atomizing effect in the tower through atomizer 2, reduce the water yield that wet desulfurization system consumes because of evaporation.Because atomizer 2 is arranged in loop slurry spraying layer 1 top, near the below of demister 3, therefore water spray does not influence the sweetening process of absorber portion.Simultaneously, the atomizing water comes from fresh water (FW), and sprays in tower, is equivalent to replenish the desulfurization consume water, therefore adopts the atomizing water not have the extra increase system process water yield.
Along with the lifting of atomizing effect, strengthened the gas-liquid heat exchanging process, flue gas is by fully cooling, and evaporated water can reduce 10% ~ 20% in the tower.Simultaneously, atomizing spray can be to accomplishing SO
2The saturated flue gas of absorption process plays cooling effect, makes the steam in the partial fume condense, and gets back in the desulphurization system.
The utlity model has following advantage.
There is the large quantity of moisture evaporation to be taken in the atmosphere in the wet fuel gas desulfurizing technology, can't recycles by flue gas.This method can effectively reduce evaporated water in the absorption tower, reduces whole wet process of FGD (FGD) system water consumption.
(1) simple, the realization easily of device.This method need not be done bigger change to the existing wet method fume desulfurizing system of power plant, only need to increase and arrange that an atomizing spray layer and respective line get final product, so cost of investment is low, realizes easily.
(2) operating cost is low.The atomizing water directly comes from fresh water (FW), and spray is equivalent to replenish the required fresh water (FW) of desulfurization in tower, does not need extra increase water consumption, and it is simple to add structure, be not easy to break down, so operating cost is very low.
(3) can reduce the desulphurization system water consumption by a relatively large margin, after experiment proof atomizing effect improved, desulphurization system can reduce 10% ~ 20% because of the water yield that evaporation consumes.