CN100427177C - Semi-wet flue gas desulfurizing treatment method and system - Google Patents

Abstract

The present invention relates to a semi-wet smoke gas desulfurizing and treating method and a system thereof. The method comprises the following steps that: a desulfurizing agent and desulfurizing ash are conveyed into a desulfurizing tower; water mist is sprayed into a smoke channel and a tower to humidify the desulfurizing agent; smoke dust which is precipitated after the volume is enlarged and the weight is increased is collected; the treated desulfurizing ash is output and is made into the products of building materials. The system comprises the desulfurizing tower, a conveying system unit, a water supply system unit, water nozzles, a smoke gas distributor, a crushing disc and an ash bucket device, wherein the conveying system unit is used for conveying the desulfurizing agent and the desulfurizing ash into the desulfurizing tower. The water nozzles which spray water and are controlled by the water supply system unit are respectively arranged in a smoke channel between a boiler outlet and an outlet of the desulfurizing tower in the desulfurizing tower, the smoke gas distributor which leads smoke gas to be uniformly distributed is arranged in the inner upper part of the desulfurizing tower, and the crushing disc for large ash blocks is arranged below the inner part of the desulfurizing tower. The inner lower part of the desulfurizing tower is connected with the ash bucket device which forms smoke dust blocks after being collecting and treating and is additionally connected with an outlet on one side of a dust remover. An exhausting port of the dust remover is reversely communicated with a conveying system unit for the desulfurizing ash, and another exhausting port of the dust remover is communicated with a chimney. The system of the present invention has the advantages of low calcium sulfur ratio required by desulfurization, high desulfurizing efficiency and low energy consumption.

Description

Semi-dry semi-wet flue gas desulfurization and processing method and system

Technical field

The present invention relates to a kind of Semi-dry semi-wet flue gas desulfurization and processing method and system.

Background technology

A certain amount of oxysulfide is contained at flue gas middle part at industry, boiler and station boiler, and general employing of existing desulfur technology has: (1) in-furnace calcium spraying afterbody humidification desulfurization technology, it is with CaCO ₃Powder sprays in the boiler, under high temperature action, and CaCO ₃Decompose and generate CaO and CO ₂, enter flue with flue gas from burner hearth after, CaO and SO ₂Chemical reaction takes place in flue and conditioning Tower generate calcium sulfite, thereby reach the desulfurization purpose, its shortcoming is the required calcium sulfur ratio height of desulfurization (3～4), desulfuration efficiency low (60%), and owing to need partial heat energy to be used for CaCO ₃Decompose, partly give vent to anger so will influence boiler.(2) rotating spraying desulfur technology, nozzle with rotation (20000 rev/mins) at a high speed sprays into lime white in the desulfurizing tower, make its atomizing, generate calcium sulfite with SO2 reaction in the flue gas, thereby reach the desulfurization purpose, its shortcoming is that floor space is big, energy consumption is high, the swivel nozzle life-span short, the operator is many, maintenance capacity is big.(3) flue gas recirculation sulfuration bed desulfur technology, this technology is to spray into a large amount of desulfurizing agent Ca (OH) in flue gas ₂With the desulfurization ash (water capacity is 5%) of humidification, make in the flue gas dust concentration from 10 original～20g/m ³To 1000g/m ³, flue-gas temperature drops to 70 ℃, and water capacity is increased to 40-50% in the flue gas.SO in the flue gas ₂Generate the sulfurous acid metal salt class, thereby reach the purpose of desulfurization with highdensity desulfurizing agent, the reaction of desulfurization ash.Its shortcoming is: increased pre-duster, increased air-introduced machine power, increased digestive system, so energy consumption has been bigger.

Summary of the invention

The purpose of this invention is to provide a kind of desulfuration efficiency height, Semi-dry semi-wet flue gas desulfurization and processing method and system that energy consumption is low.

For achieving the above object, the present invention adopts following technical scheme:

This semi-wet flue gas desulfurizing and processing method are as follows:

A, startup batcher are carried desulfurizing agent, desulfurization ash with steam in desulfurizing tower;

B, start the water supply system unit, last water, atomized water spray in flue, in the desulfurizing tower is with to flue gas, desulfurizing agent humidification;

The flue dust of c, the increase back sedimentation of will increasing weight drops at the bottom of the desulfurizing tower after handling with large dust lump breaking disc, is discharged by the outlet at the bottom of the desulfurizing tower, collects; Simultaneously, the desulfurization ash is input in the deduster through soft pipeline by the side outlet;

D, after deduster is handled with the outlet output of a part of desulfurization ash at the bottom of the desulfurizing tower, add a certain proportion of fine sand, send another part desulfurization ash back to desulfurization ashes storehouse, use again in order to next flow process;

E, the desulfurization ash that will add fine sand are sent into compression moulding in the humidification make-up machine; Second hand rail road car is sent in the steam-cured jar of building materials, comes out after timing, makes building material product.

The system of this semi-wet flue gas desulfurizing and processing comprises:

One desulfurizing tower;

One carries the induction system unit of desulfurizing agent and desulfurization ash in desulfurizing tower:

One water supply system unit;

Respectively establish one group of (operating) water nozzle in flue between boiler export and desulfurizing tower inlet and the desulfurizing tower, each (operating) water nozzle is sprayed water by the water supply system unit controls; Establish one above in desulfurizing tower and make the equally distributed flue gas distributor of flue gas, a large dust lump breaking disc is established in the below, a bottom outlet and a side outlet are established in the bottom of desulfurizing tower, establish the ash hopper device that collection forms fume lump after treatment below the bottom outlet of desulfurizing tower, side outlet is connected to a deduster through flexible pipe; Deduster is established unconventional sulphur ash induction system unit mouth, mouth, the following row mouth to brickmaking building materials system unit that leads in chimney.

It is proportional that described desulfurizing tower diameter and boiler steam ton.

Flue gas distributor in the described desulfurizing tower is a disk with certain altitude (high 1 meter), is provided with vertically (calculate and be provided with by the formula of bottom) a plurality of smoke distribution barriers in the annulus of disk and is separated into the space of a fixed number.The empirical equation that concerns that the diameter D of flue gas distributor disk and boiler steam tonnage A is:

$D=0.5672\sqrt{A}-(\frac{A}{100}~\frac{A}{80})$

B is counted in the space that the smoke distribution barrier is separated in the flue gas distributor disk:

$B=\frac{A}{3}+(0.7~1)$

The unit of diameter D is a rice, and boiler steams tonnage A and do not get dimension.

The nozzle of the (operating) water nozzle in the described desulfurizing tower is provided with angle beta and is:

$\mathrm{\β}=\mathrm{arctg}[\mathrm{0,886}D(\sqrt{\frac{A}{10B}}~\sqrt{\frac{A}{6B}})$

Stove steams tonnage A and does not get dimension.

Advantage of the present invention is: the required calcium sulfur ratio of desulfurization low (1.5), and desulfuration efficiency height (75～90%), energy consumption is low.

Description of drawings

Fig. 1 is semi-wet flue gas desulfurizing of the present invention and treatment system structural representation

The specific embodiment

Semi-wet flue gas desulfurizing and processing method are as follows:

1, a kind of semi-wet flue gas desulfurizing and processing method is characterized in that method is as follows:

A, startup batcher are carried desulfurizing agent in desulfurizing tower;

B, start the water supply system unit, last water, atomized water spray in flue, in the desulfurizing tower is with to flue gas flue dust, desulfurizing agent humidification;

Discharge by the outlet at the bottom of the desulfurizing tower at the bottom of dropping to desulfurizing tower after the flue dust of c, the increase back sedimentation of will increasing weight is handled with large dust lump breaking disc, collect; Simultaneously, the desulfurization ash is arranged after soft pipeline is input in the deduster by side;

D, after deduster is handled with the outlet output of a part of desulfurization ash at the bottom of the desulfurizing tower, add a certain proportion of fine sand, send a part of desulfurization ash back to desulfurization ashes storehouse, use again in order to next flow process;

E, the desulfurization ash that will add fine sand are sent into compression moulding in the humidification make-up machine; Second hand rail road car is sent in the steam-cured jar of building materials, through come out after the timing (about maintenance 8 hours), makes building material product.

As shown in Figure 1, semi-wet flue gas desulfurizing of the present invention and treatment system, comprise that a desulfurizing tower 3, carries the induction system unit 2 of desulfurizing agent and desulfurization ash in desulfurizing tower, other is provided with a water supply system unit 1, respectively establish one group of (operating) water nozzle 4 in flue between boiler export and desulfurizing tower inlet and the tower, each (operating) water nozzle is sprayed water by the water supply system unit controls; Establish one above in desulfurizing tower and make the equally distributed flue gas distributor 301 of flue gas, a large dust lump breaking disc 302 is established in the below, a bottom outlet, a side outlet are established in the bottom, below bottom outlet, establish the ash hopper device 5 that collection forms fume lump after treatment, side outlet is connected to static or sack cleaner 6 through flexible pipe, and deduster is established a unconventional sulphur ash induction system unit mouth 601, and led to the following row mouth 603 of the mouth 602, of ten chimneys to brickmaking building materials system unit.

Water supply system unit 1 is made up of tank 101, high pressure water pump 102 and corresponding monitoring form, control valve and pipeline, its effect is with form while to flue, desulfurizing tower in the atomized water spray of water with water smoke 100-50 μ m, reach and reduce the cigarette temperature (from 150 ℃ → 70 ℃,), give flue dust, desulfurizing agent humidification in the flue gas, make SO ₂Generate H with the water reaction ₂SO ₃And CaO and H ₂O generates Ca (OH) ₂Purpose, play simultaneously and make Ca (OH) as the disturbing source of flue gas ₂With H ₂SO ₃Fully contact increases the two reaction probability, reduces the direct and H of CaO ₂The purpose of the chemical reaction activation energy of O reaction, during water, the flow velocity of water out is 30-45m/s, spray angle 35-100 ° on the water supply system.

The induction system unit 2 of desulfurizing agent and desulfurization ash is made up of desulfurizing agent feed bin 201, desulfurization ashes storehouse 203, desulfurizing agent, desulfurization ash constant feeder 202,204 and desulfurizing agent, desulfurization ash nozzle 205, and can to adopt steam to carry particle diameter be 200 orders-300 purpose CaO powder, the H of CaO in course of conveying and in the steam ₂The O reaction generates Ca (OH) ₂(CaO digestion process), and make Ca (OH) ₂Reach the effect of humidification, realized that desulfurizing agent CaO digestion conveying humidification is integrated.

Described desulfurizing tower 3 is improved on existing desulfurizing tower foundation structure, 301, one groups of (operating) water nozzles of one flue gas distributor, 4, one large dust lump breaking discs 302 are set in tower, a bottom outlet, a side outlet are established in the bottom, establish the ash hopper device 5 that collection forms fume lump after treatment below bottom outlet.It is proportional that described desulfurizing tower diameter and boiler steam ton.

Boiler steams the relation of injection flow rate in tonnage and tower diameter and the tower

Boiler steams tonnage	Tower diameter m	Injection flow rate t/h
			35	Φ3.6	3.5
65	Φ4.6	6.4
			75	Φ4.8	7.1
110	Φ5.8	10
			220	Φ8.2	20
410	Φ8.4	39

Because desulfurizing tower is to create H ₂SO ₃With Ca (OH) ₂Fully contact and make in the tower not condition, so the flue gas distributor structure in it and the calculating of nozzle angle and water pressure just seem very important because of the water spray fouling.

The flue gas distributor principles of structural design is after guaranteeing that flue gas enters desulfurizing tower, particularly under atomized water spray disturbance situation, still can keep the advection motion.It is the disk of a high 1m, the diameter of disk and different the changing of the interior smoke distribution barrier of annulus according to flue gas flow size and the total injection flow rate of get.The empirical equation that disk diameter changes is: $D=0.5672\sqrt{A}-(\frac{A}{100}~\frac{A}{80})$

The A-boiler steams tonnage (not getting dimension)

The diameter of D-disk (m)

The space number that the smoke distribution barrier is separated in the flue gas distributor disk with the empirical equation that boiler steams the tonnage variation is: $B=\frac{A}{3}+(0.7~1)$

The space number that the B-barrier is enclosed

The A-boiler steams tonnage (not getting dimension)

(operating) water nozzle 4 in the described desulfurizing tower is arranged in tower ringwise, generally arranges the 1-2 layer, every layer of 3-6 nozzle, and the angle beta that is provided with of nozzle is:

$\mathrm{\β}=\mathrm{arctg}[\mathrm{0,886}D(\sqrt{\frac{A}{10B}}~\sqrt{\frac{A}{6B}})$

Wherein: D-disk diameter (not getting dimension)

The A-boiler steams tonnage (not getting dimension)

B-barrier enclosed space number (not getting dimension)

β-nozzle angle (β °)

Nozzle angle is controlled at 35 ° of-100 ° of scopes.

The water smoke flow velocity of nozzle ejection should be 5-10 with the ratio of flue gas flow rate, can reach like this to make the humidification air be covered with water smoke, simultaneously flue gas is had the effect of disturbance.Under the water smoke effect, flue gas becomes around the tower wall flue gas flow rate and accelerates to some extent by evenly flowing in the original tower, alleviated wet wall phenomenon greatly, makes flue gas, the water smoke flow field in tower reach perfect condition.

SO in the flue gas in desulfurizing tower and flue ₂Generate H with the water reaction ₂SO ₃, and the same Ca of humidification (OH) ₂Reaction generates CaSO ₃* H ₂Thereby O has changed CaO and SO ₂Directly Fan Ying course greatly reduces reaction activity, has improved reaction speed, has reached higher desulfuration efficiency (75-90%).Because flue gas flow velocity in tower reduces, and has created condition for atomized water spray makes the flue gas disturbance, makes H ₂SO ₃With Ca (OH) ₂The reaction probability improves, and also plays the purpose that improves desulfuration efficiency indirectly.In the flue gas humidification process, also make the flue dust humidification simultaneously, the flue dust weight behind the humidification increases, and is easy to mutual closing with fixed attention, and the flue dust particle diameter is increased, and the flue dust after the increase weightening finish is deposited in the bottom of tower under the gravity effect, reached the purpose of dedusting.

Deduster 6 is established unconventional sulphur ash induction system unit mouth 601 one time: can with through the desulfurizing agent after the desulfurization and the feedback of part flyash in desulfurization ashes storehouse 203, together use jointly with new desulfurizing agent, give full play to the desulfurizing agent of not utilization and the active component of flyash, reach utilization ratio that improves desulfurizing agent and the effect that improves desulfuration efficiency.

Deduster 6 is provided with mouth 602, the one following row to a brickmaking building materials system unit [mouth 603 that leads in chimney in addition.

Described brickmaking building materials system unit comprises can complete operation one humidification make-up machine 7, steam-cured jar 9 of a railcar 8, building materials, and desulfurization ash and flyash after recycling (contain FeO, Na ₂O, SiO ₂Deng), a certain proportion of fine sand of adapted (200-300 order) again, compression moulding in the humidification make-up machine is sent in steam-cured jar of the building materials with railcar, in steam-cured jar, unreacted CaO, Ca (OH) in the desulfurization refuse of humidification moulding ₂, H ₂O and devitrification accessory substance CaSO ₃, CaSO ₄And initiate sand (main component SiO ₂) effect of oxidation in steam (1.0MPa～1.5MPa, 110-150 ℃) and air generates down the hydrate gel.

MCa (OH) ₂+ SiO ₂+ (n-1) H ₂O-→ CaOSiO ₂NH ₂O (CAH gel)

MCa (OH) ₂+ Al ₂O ₃+ (r-1) H ₂O-→ CaOAl ₂O ₃NH ₂O (CAH gel)

CaSO ₃Under the effect of oxygen oxidation reaction taking place, generates CaSO ₄Following reaction in the presence of gypsum, takes place in (gypsum)

mCaO·Al ₂O ₃·nH ₂O+CaSO ₄·2H ₂O-→

MCaOAl ₂O ₃3CaSO ₄(n+2) H ₂O) (tungsten aluminite)

And generating tungsten aluminite, this material helps the generation of gel.

Ca (OH) here ₂, CaSO ₄Promoted the generation of gel as exciting agent, the building materials that desulfurization ash, sand are formed have the intensity more taller than traditional common brick.Owing to contained CaO, Ca (OH) in the desulfurization ash ₂, CaSO ₄So,, this method adds the cost low 20% of CaO than pure brick making from fly-ash.In native system, realized CaSO ₃Oxidation and steam-cured legal system building materials integrated simplified system building materials technology greatly, reduced the consumption that flyash system building materials will add fresh CaO, played twice laid, reduces the effect of flyash system building material cost.

Claims (10)

1, a kind of semi-wet flue gas desulfurizing and processing method is characterized in that method is as follows:

A, startup batcher are carried desulfurizing agent, desulfurization ash with steam in desulfurizing tower;

B, start the water supply system unit, last water, atomized water spray in flue, in the desulfurizing tower, with to flue gas flue dust, desulfurizing agent humidification:

Discharge by the outlet at the bottom of the desulfurizing tower at the bottom of dropping to desulfurizing tower after the flue dust of c, the increase back sedimentation of will increasing weight is handled with large dust lump breaking disc, collect; Simultaneously, the desulfurization ash is arranged after soft pipeline is input in the deduster by side;

D, after deduster is handled with the outlet output of a part of desulfurization ash at the bottom of the desulfurizing tower, add a certain proportion of fine sand, send a part of desulfurization ash back to desulfurization ashes storehouse, use again in order to next flow process;

E, the desulfurization ash that will add fine sand are sent into compression moulding in the humidification make-up machine; Second hand rail road car is sent in the steam-cured jar of building materials, and building material product is made in maintenance 8 hours.

2, semi-wet flue gas desulfurizing as claimed in claim 1 and processing method is characterized in that: during water, the flow velocity of water out is 30-45m/s, spray angle 35-100 ° on the water supply system unit.

3, a kind of semi-wet flue gas desulfurizing and treatment system that realizes the described method of claim 1, comprise that a desulfurizing tower, carries the induction system unit of desulfurizing agent and desulfurization ash in desulfurizing tower, it is characterized in that: a water supply system unit is set, respectively establish one group of (operating) water nozzle in flue between boiler export and desulfurizing tower inlet and the desulfurizing tower, each (operating) water nozzle is sprayed water by the water supply system unit controls; Establish one above in desulfurizing tower and make the equally distributed flue gas distributor of flue gas, a large dust lump breaking disc is established in the below, a bottom outlet and a side outlet are established in the bottom of desulfurizing tower, below the bottom outlet of desulfurizing tower, establish the ash hopper device that collection forms fume lump after treatment, side outlet is connected to a deduster through flexible pipe, and deduster is established the mouth of a unconventional sulphur ash induction system unit.

4, semi-wet flue gas desulfurizing as claimed in claim 3 and treatment system is characterized in that: it is proportional that described desulfurizing tower diameter and boiler steam ton.

5, semi-wet flue gas desulfurizing as claimed in claim 3 and treatment system is characterized in that: the flue gas distributor in the described desulfurizing tower is a high disk of 1 meter, is provided with a plurality of smoke distribution barriers in the annulus of disk.

6, semi-wet flue gas desulfurizing as claimed in claim 5 and treatment system is characterized in that the diameter D of described flue gas distributor disk and the empirical equation that concerns that boiler steams tonnage A are:

$D=0.5672\sqrt{A}-(\frac{A}{100}~\frac{A}{80})$

The unit of diameter D is a rice, and boiler steams tonnage A and do not get dimension.

7, semi-wet flue gas desulfurizing as claimed in claim 5 and treatment system is characterized in that the smoke distribution barrier is separated in the described flue gas distributor disk space counts B and steam the empirical equation that tonnage A changes with boiler and be:

$B=\frac{A}{3}+(0.7~1)$

Boiler steams tonnage A and does not get dimension.

8, semi-wet flue gas desulfurizing as claimed in claim 3 and treatment system, the nozzle that it is characterized in that one group of (operating) water nozzle in the described desulfurizing tower is provided with angle beta and is:

9, semi-wet flue gas desulfurizing as claimed in claim 3 and treatment system is characterized in that: it is 200 orders-300 purpose CaO powder that the described desulfurization ash of carrying in desulfurizing tower can adopt steam to carry particle diameter.

10, semi-wet flue gas desulfurizing as claimed in claim 3 and treatment system, it is characterized in that: described deduster also is provided with one to the following row of brickmaking building materials system unit mouthful, described brickmaking building materials system unit comprise one can complete operation steam-cured jar of humidification make-up machine, railcar, building materials.