CN1215349A

CN1215349A - Device for discharging and distributing an absorbent in a flue gas duct

Info

Publication number: CN1215349A
Application number: CN97193574A
Authority: CN
Inventors: 斯蒂芬·奥曼; 尼尔斯·布林格福思; 拉尔斯·E·约翰松
Original assignee: ABB Flaekt AB
Current assignee: ABB Technology FLB AB
Priority date: 1996-04-04
Filing date: 1997-03-17
Publication date: 1999-04-28
Also published as: EE9800316A; ID16651A; CZ291809B6; ZA972809B; SE9601303D0; EP0891219A1; CZ319298A3; SE9601303L; CA2251473A1; TR199700269A1; SI9720030A; AU2415297A; WO1997037747A1; HRP970182A2; PL329157A1; TW359741B; JP2000508576A; SE506249C2

Abstract

In a vertical flue gas duct (10), in which flue gases containing gaseous pollutants are to be conducted upwards, a discharging and distributing device is arranged. The device is adapted to discharge and distribute a particulate absorbent material which is reactive with the gaseous pollutants in the flue gases and which, during cleaning of the flue gases, is to be introduced into these gases in moistened state in order to convert the gaseous pollutants to separable dust. The device comprises at least one distributing plate (35) which extends obliquely downwards in the flue gas duct (10) and which is adapted to receive on its upper side moistened absorbent material and which has two well-defined side edges converging obliquely downwards seen in the direction of inclination.

Description

Be used for device at waste gas duct discharging and distribution absorbent material

The present invention relates to a kind of device that is arranged in the vertical substantially waste gas duct, in this conduit, the waste gas that contains gaseous contaminant such as sulfur dioxide is upwards guided, this device is used at waste gas duct discharging and dispersed particulates shape absorbent material, this absorbent material can react with the gaseous contaminant in the waste gas and be admitted to these gas with moistening state when purifying exhaust air, so that gaseous contaminant is transformed into separable dust.

When gaseous contaminant such as sulfur dioxide are prepared to be separated from waste gas, gas was led waste gas duct, in this conduit, can be admitted in the waste gas with moistening state with the granular absorbing material that gaseous contaminant reacts, so that gaseous contaminant is transformed into separable dust.After, just waste gas was led deduster, dust separates with waste gas in deduster, is drawn out of from deduster through purified waste gas.The dust that separates in deduster of a part is sent to blender, and it is mixed and water is moistening at this place, after, it is by along with adding that new absorbent is admitted to waste gas and being repeated to utilize as absorbent material.As new absorbent, all use calcium hydroxide (calcium hydroxide) usually.

In order to use the effective and efficient manner purifying exhaust air, important yes that absorbent material is sent in the waste gas as the mixture of homogeneous, and moisture content will distribute in the mixture of homogeneous equably.A kind of device is disclosed in WO96/16727, advantageous particularly when it is used to make the mixture of the absorbent material of homogeneous and water in above-mentioned method for treating exhaust gas.This mixing arrangement comprises a container, in mixture operation, the granular absorbing material in container by fluidization.Container has the port of export that stretches into waste gas duct, and it is used for by overflow the absorbent material of homogeneous and the mixture of water being disposed to waste gas duct.

For waste gas can be cleaned effectively, important also has, and in the entire cross section of waste gas duct, moistening absorbent material will evenly distribute.This uniform distribution is to reach with the overflow in the above-mentioned mixing arrangement.

Therefore, purpose of the present invention is for providing a kind of device, it can use in above-mentioned mixing arrangement and other mixing arrangement simultaneously, is dispersed on the entire cross section of waste gas duct in uniform mode so that will be disposed to the waste gas duct and with it from the moistening absorbent material that mixing arrangement receives.

According to the present invention, this purpose can reach by a kind of device, this device is the sort of type of mentioning as foreword, it is characterized by, it comprises that at least one stretches into the distribution grid in the above-mentioned waste gas duct obliquely downwards, this plate is used for the absorbent material of side joint hygroscopic profit thereon, and above-mentioned distribution grid has two lateral margins that are perfectly clear, and this lateral margin is along inclined direction looked to shrinking downwards obliquely.

Device preferably has at least two distribution grids respect to one another.

In a preferred embodiment, distribution grid is centrally located on the waste gas duct from its distribution apparatus that stretches out downwards obliquely, to be emitted on the moistening absorbent material on the distribution grid.

Distribution grid is preferably triangle.

With reference now to accompanying drawing, the present invention is described in more detail, in these accompanying drawings,

Fig. 1 is the schematic representation of apparatus of waste gas that is used to purify the center heating power factory of spontaneous combustion coal;

Fig. 2 is the side view that the blender of device of the present invention is housed, and some part is broken away;

Fig. 3 is the plan view from above of the blender of Fig. 2; And

Fig. 4 is the cutaway view of the IV-IV line along Fig. 3.

Fig. 1 schematically shows the device of the waste gas of the center heating power factory 1 that is used to purify spontaneous combustion coal, and above-mentioned waste gas contains dust such as coal ash.One preheater 2 is set, the waste gas of heat from heat is reached the combustion air, this combustion air is sent to center heating power factory 1 with fan 3 through conduit 2a.

The waste gas of heat is sent in the deduster 5 by conduit 4, and this deduster shown in an embodiment be a fabric filter, and it contains many row's filter bags in the mode of knowing, and waste gas is cleaned by its preparation.So be conducted to exhaust fan 7 through purified waste gas by conduit 6, fan 7 is further delivered to chimney 9 by conduit 8 with it, is disposed in the atmosphere.Deduster can for example be an electrostatic precipitator also.

Conduit 4 has a vertical component 10.Blender 11 is communicated with this part in its underpart.Blender 11 is sent into moistening grit in the waste gas in the bottom of duct portion 10 in the mode that is described in greater detail below.

The grit that separates in deduster 5 is collected in the feed bin 12 of deduster 5.The grit that a part is collected was repeated to utilize in system by sending blender 11 (arrow P 1).The remainder of the grit of collecting for example is removed with auger conveyor in a kind of mode of not describing in detail.

Blender 11 is blenders of disclosed the sort of type in WO 96/16727, and in more detail shown in Fig. 2～4.

Blender 11 shown in Fig. 2～4 comprises a container 13, and it makees the chest of the parallelepiped of growth basically.Container 13 have the vertical front bulkhead 17 of two vertical sidewalls 14 aft bulkhead vertical 16,, a level with 15, one upper base 18, a level 19 and one level of going to the bottom the top or cover 20.

In the rear end, container 13 has an inlet 21, is sent into (arrow P 1 among Fig. 1 and 2) in the container 13 from the grit of feed bin 12 from above by it, at front end, container has an outlet 22, and the uniform homogeneous blend of grit and water is discharged (arrow P 2 among Fig. 3 and 4) by it.

In the drawings, the front end of container 13 inserts vertical duct portion 10, and waste gas is upwards guided (arrow P 3 among Fig. 1,2 and 4) by it.In this used, outlet 22 was overfalls, its formation be because, when container inserted in the major part of part of duct portion 10,

sidewall

14 and 15 will be lower than the part that container is positioned at the outside of duct portion 10.Can find out that from Fig. 2 and 3 top 20 21 extends to outlet 22 from entering the mouth, promptly until duct portion 10.

Marking a Room 23 at the bottom of two between 18 and 19, it in side direction by two

sidewalls

14 and 15 boundaries, vertically by two

end walls

16 and 17 boundaries.The fluffy fluidization cloth that is upper base 18 is made of polyester by breathable in sky of chamber 23 is formed, and this cloth is contained in the container 13 with the state of upholding.Be provided with one herein by two

air intakes

24 and 25 air feeders of forming, with to chamber 23 air supplies (arrow P 4 among Fig. 2 and 3), so that grit fluidization in container 13.

The water supply line 26 that is arranged on the top of container 13 links to each other with a plurality of nozzles 27 that are arranged in the top of container 13, to cut apart to such an extent that very thin shape was sprayed grit in the container with water.The nozzle 27 that a few only is shown is in the drawings put with two parallel arranging and is extended along container 13.

Two trunnion axis arranged side by side 28,28 ' extend and use bearing 29,29 ' and 30,30 ' rotatably to be contained on two

end walls

16 and 17 respectively along entire container 13.One motor 31 is set, by transmission device 32 turning cylinders 28,28 '.

Every axle 28,28 ' all supports a plurality of oblong-shaped disc 33,33 ', a separate each other axial distance and be installed on the axle 28,28 ' with the state that tilts around its minor axis of this dish.Axle 28,28 ' passes dish 33 separately, 33 ' center.In the example shown, each dish 33,33 ' so tilts with respect to axle 28,28 ', so that the angle [alpha] between the major axis of dish and the axle 28,28 ' is about 60 ° of (see figure 2)s.This angle [alpha] can change between 45 ° and 80 °.Dish 33,33 ' so tilts with respect to axle 28,28 ' separately, and so elliptical shape is arranged, so that as shown in Figure 4, the axis projection of a circle is arranged.Dish 33,33' will so be positioned on separately the axle 28,28 ', so that the dish on axle stretches in the space between another the dish.

The dish arranging and design by top pointed mode 33,33 ' each all when axle 28,28 ' rotation, carry out a sling movement, the whole process of mixing through grit.

The partition 34 of the front portion by container 13, chamber 23 is divided into anterior chamber 23a and chamber, the rear portion 23b that is arranged in duct portion 10.Can see that from Fig. 2 air intake 24 openings are in the 23b of chamber, rear portion, air intake 25 then opening arrives in the anterior chamber 23a.Chamber 23 is so cut apart, just might in two parts chamber 23a and 23b, be obtained different fluidization situations, particularly in order so to be adjusted to the air supply of anterior chamber 23a, so that people can obtain being used for the fluidized state of material discharge at this place.

The part that is used for reusing in system of the grit of collecting in the feed bin 12 of deduster 5 is admitted to blender 11 through inlet 21.Grit is moistening with the water of supplying with by nozzle 27.Owing to the structure of mechanical mixture mechanism with owing to be conducted to the fluidization of the grit of blender, blender 11 is produced the moistening equably uniform homogeneous blend of grit, and it is sent in the duct portion 10 continuously by the overfall 22 of blender 11.

In order to scatter the moistening equably uniform homogeneous blend of grit equably on the entire cross section of duct portion 10 in waste gas, above-mentioned blender 11 has all added according to device of the present invention.

This dissemination apparatus comprises four straight distribution grids 35 in the example shown, and each all has the shape of isosceles triangle.The ratio of the end of isosceles triangle with height is 0.2～0.4, is preferably 0.25～0.35.

Two of plate 35 are contained on the sidewall 14 of container 13 of the container part that inserts duct portion 10 in a parallel manner.All the other two plates 35 are contained on another sidewall 15 of container 13, one front in each plate on being contained in sidewall 14.The end of each distribution grid 35, all be arranged on the level identical with overfall 22 and the

sidewall

14,15 that is parallel to separately extends.Distribution grid 35 tilts, and stretches out downwards on duct portion 10 medium dips ground.Plate 35 and horizontal plane be β at angle, and it is about 45 ° in the embodiment shown.Angle beta can change in 10 °～80 °, and is preferably 30 °～50 °.

The horizontal range a that each distribution grid 35 leaves the adjacent wall of duct portion 10 is 0～0.5 with its ratio (see figure 4) along the length b of the projection in a horizontal plane of projection direction, is preferably 0.1～0.3.

Deduction is stretched into the cross-sectional area that the blender of duct portion partly occupies, distribution grid 35 projection in a horizontal plane occupy duct portion 10 total cross section 5%～50%, be preferably for 20%～30% (being about 30% in the example shown).

Blender 11 is emitted on moistening equably grit on the distribution grid 35 by overfall 22.These grits also in turn arrive lateral margin that it be perfectly clear along plate 35 to gliding by the gravity effect.At this place, because the structure and the position of plate 30, the waste gas stream in the duct portion 10 obtains high velocity gradient, and any grit piece that may exist is torn, and grit is dispensed on the entire cross section that is dispersed in duct portion in the waste gas and in waste gas.In addition, because their structure, plate 35 produces vortex in waste gas, and it produces comprehensive mixing of the reinforcement of grit in waste gas.

Will be appreciated that above-mentioned dissemination apparatus can improve within the scope of the invention in various manners.Thereby, distribution grid 35 can have with shown in the different triangle of isosceles triangle.Plate 35 even need not to be triangle, but diverse shape can be arranged, as long as they just have two lateral margins that are perfectly clear of along inclined direction looking and shrinking for obliquely, distribution grid 35 needs not to be straight, but can be recessed or epirelief in some applications.Certainly, the number of distribution grid 35 will adapt to relevant application.In some cases, only just enough with a plate 35.

Naturally it should also be appreciated that dissemination apparatus of the present invention also can be used in other mixing arrangement or tapping equipment rather than the top blender described in detail 11.That part of of duct portion 10 that stretch into of blender 11 can be for example replaces with a level board, and moistening grit can be delivered on this level board from the blender of any kind.

Claims

1. device that is arranged in the vertical substantially waste gas duct (10), in this conduit, the waste gas that contains gaseous contaminant such as sulfur dioxide is upwards guided, this device is used at waste gas duct (10) discharging and dispersed particulates shape absorbent material, this absorbent material can react with the gaseous contaminant in the waste gas and be admitted to these gas with moistening state when purifying exhaust air, so that gaseous contaminant is transformed into separable dust, it is characterized by, it comprises that at least one stretches into the distribution grid (35) in the above-mentioned waste gas duct (10) obliquely downwards, this plate is used for the absorbent material of side joint hygroscopic profit thereon, above-mentioned distribution grid has two lateral margins that are perfectly clear, and this lateral margin is along inclined direction looked to shrinking downwards obliquely.

2. device as claimed in claim 1 is characterized by, and it has at least two distribution grids respect to one another (35).

3. device as claimed in claim 2 is characterized by, and it has a tapping equipment (11,22), and this device is centrally located in the waste gas duct (10), and distribution grid (35) stretches out downwards obliquely from it, and this device is used for moistening absorbent material is disposed to distribution grid.

4. device as claimed in claim 3 is characterized by, and the horizontal range (a) that each distribution grid (35) leaves the adjacent wall of waste gas duct is 0～0.5 with its ratio along the length (b) of the projection in a horizontal plane of projection direction, is preferably 0.1～0.3.

5. as the device of claim 3 or 4, it is characterized by, deduction is discharged the cross-sectional area that device (11,22) occupies, distribution grid (35) projection in a horizontal plane occupy waste gas duct (10) total cross-sectional area 5%～50%, be preferably 20%～30%.

6. as each the device in the claim 1～5, it is characterized by, each distribution grid (35) becomes 10 °～80 ° angles (β) that are preferably 30 °～50 ° with horizontal plane.

7. as each the device in the claim 1～6, it is characterized by, each distribution grid (35) all is leg-of-mutton.

8. device as claimed in claim 7 is characterized by, and each distribution grid (35) is made the shape of isosceles triangle.

9. device as claimed in claim 8 is characterized by, and the ratio of the end of isosceles triangle with height is 0.2～0.4, is preferably 0.25～0.35.