CN1037194C

CN1037194C - Preheating device of raw briquet

Info

Publication number: CN1037194C
Application number: CN94107305A
Authority: CN
Inventors: 任志国
Original assignee: Central Iron and Steel Research Institute
Current assignee: Central Iron and Steel Research Institute
Priority date: 1994-06-29
Filing date: 1994-06-29
Publication date: 1998-01-28
Anticipated expiration: 2014-06-29
Also published as: CN1099420A

Abstract

The present invention relates to a preheating device of raw briquets, which is suitable to use for preheating cold raw briquets in an iron concentrate belt-type briquet roasting machine and a grate kiln. The device is composed of a raw briquet distributing system, a heat exchange system and a hot air supply system; the device is mainly characterized in that the present invention is utilized to preheat the raw briquets to an average temperature more than 60 DEG C before the raw briquets are roasted,; a forced air drying section is not arranged in the roasting system when the temperature exceeds a dew point temperature, which can prevent the briquets from being damaged because of overwetness during drying. The device effectively improves the utilization coefficient of roasting machines, and has the advantages of simple technological process, convenient operation, etc.

Description

Preheating device of raw briquet

The invention belongs to fine iron breeze agglomeration field, be specially adapted to iron ore concentrate belt pellet roasting machine and chain grate machine rotary kiln, be used for the cold green pellets of preheating.

Belt pellet roasting machine and chain grate machine rotary kiln in the prior art, all be with the direct cloth of cold green pellets to the chassis of belt type roasting machine or chain grate machine, enter roasting process then, because cold green pellets temperature is low, in the exhausting drying process, the pelletizing surface of material layer lower part forms one deck water of condensation, promptly forms so-called excessive moistening layer, influences the ventilation property of the bed of material.In order to overcome this problem, belt pellet roasting machine and chain grate machine will be established blasting drying period before the exhausting drying, with the pelletizing of preheating material layer lower part.This pre-heating mean, make the pellet roasting technological process become complicated, process gas flow is wayward, in the forced air drying process, the pelletizing on bed of material top will form excessive moistening layer equally, in addition, the roasting area because blasting drying period itself and intermediate seal thereof have accounted for has reduced the utilization coefficient of burning machine.

The object of the invention is to provide a kind of preheating device of raw briquet, it can not only avoid green pellets to produce wet destruction in the exhausting drying process, can also make belt pellet roasting machine and chain grate machine not establish blasting drying period, improves the utilization coefficient of burning machine, make technical process simple, be convenient to operation.

In order to achieve the above object, preheating device of raw briquet of the present invention is made up of green pellets cloth system, heat exchange system, hot wind supply system three parts, wherein the green pellets cloth system by shuttle-type distributor, green pellets fall snubber, the snubber cleaner is formed, heat exchange system is made up of petticoat pipe, feed bin, draught hood, pre-hott bed, wide leather belt material distributing device, and the hot wind supply system is made up of hot blast jet pipe, thermopair, cold wind mixing wind tube.The constructional feature of this device is: upward rectangle petticoat pipe and last rectangle inferior pyramidal feed bin connect the shell that constitutes heat exchange system under the shape of garden by flange, pre-hott bed is to be placed on along the axis direction by many grate bars, on the skeleton of center protrusion, forming center protrusion can be by the double inclined plane porous bed surface of hot gas, skeletal fixation is in the middle and upper part of feed bin, the shuttle-type distributor is positioned on the axis, top of pre-hott bed, the hot blast jet pipe of heat exchange system is positioned on the axis, pre-hott bed bottom, it is peripheral that draught hood is positioned at the outlet of feed bin lower end, and wide leather belt material distributing device is positioned at the bin outlet lower end.This inclined-plane that installs pre-hott bed equates with the natural angle of rest (repose) of green pellets with the angle of horizontal plane or is close, and can not coexist according to processing condition and adjust in 30 °～50 ° scopes, pre-hott bed two bevel edges from the distance of bin wall greater than 100mm, fall with the pelletizing that guarantees preheating, in addition, the hot blast temperature of hot wind supply system can require to adjust by the air quantity of regulating the cold wind mixing wind tube according to pre-heating technique.

Technical process of the present invention and principle are as follows: the green pellets of making, through the shuttle-type distributor to pre-hott bed, green pellets is spread certain thickness equably on pre-hott bed, form the cold green pellets bed of material, hot blast from the hot wind supply system, spray by the hot blast jet pipe, hot blast is through the double inclined plane porous grate bar bed surface of pre-hott bed, enter the green pellets bed of material, with the green-ball preheating,, remove a part of moisture content simultaneously by transmission of heat by convection to more than 60 ℃, in order to control the preheating speed of green pellets, prevent from the green pellets warm to produce cracked, can mix a part of cold wind sometimes from the hot blast of hot wind supply system, the good green pellets of preheating is distributed into wide leather belt material distributing device by the lower part outlet of feed bin, and moving ahead cloth to the chassis of burning machine thereupon, hot waste gas then enters in the atmosphere by petticoat pipe.

Compared with prior art, the invention has the advantages that:

1, adopt preheating device of raw briquet preheating green pellets of the present invention, because the temperature after the pelletizing preheating has surpassed dew-point temperature, the down-draft drying zone of pelletizing in roasting process can not form excessive moistening layer like this, and wet destruction taken place.

2, behind employing the present invention, pellet firing machine can not established blasting drying period, has improved the utilization coefficient of burning machine effectively.Simplify the tightness system of burning machine, reduced burning machine and leaked out, improved the burning machine environment.

3, technical process is simple, and is easy to operate.Can arbitrarily adjust pre-hot gas flow with processing requirement.Make the roasting process process gas flow more reasonable.

Below in conjunction with accompanying drawing green pellets preheater of the present invention is described further.

Fig. 1 is the structural representation of facing of preheating device of raw briquet of the present invention.

Fig. 2 is an A-A diagrammatic cross-section among Fig. 1.

Among Fig. 1, Fig. 2,1 is wide leather belt material distributing device, and 2 is draught hood, and 3 is feed bin, and 4 is the hot blast jet pipe, 5 is pre-hott bed, the 6 pelletizing bed of materials of making a living, and 7 for green pellets falls snubber, and 8 is rib formula distributor, 9 is petticoat pipe, and 10 is the snubber cleaner, and 11 is thermopair, and 12 is the cold wind mixing wind tube.

Technical process of the present invention realizes as follows: the green pellets of making, by shuttle-type distributor (8), green pellets falls snubber (7), cloth is to the pre-hott bed of green-ball (5) equably, because the surface slope of the pre-hott bed of green-ball (5) is identical or approaching with green-ball nature angle of rest (repose), become uniform one deck by the gravity green-ball on pre-hott bed upper berth, form the green pellets bed of material (6), break when the green pellets bed of material (6) is gone up for preventing that green pellets from falling from rib formula distributor (8), be provided with green pellets and fall snubber (7), for preventing that green pellets from falling snubber (7) sizing when working, be provided with snubber cleaner (10), can fall snubber (7) to green pellets periodically and carry out Hand scarf.Hot blast from the pellet roasting system, requirement according to pre-heating technique, by cold wind mixing wind tube (12), the temperature of control hot blast, cracked in warm to prevent green pellets, by thermopair (11) calorimetric wind-warm syndrome degree, and then spray in the empty thorax below pre-hott bed (5) the grate bar by the spray orifice on the hot blast jet pipe (4), hot blast enters the green pellets bed of material (6) by the grate bar and realizes convective heat exchange, cold green pellets is preheating to average more than 60 ℃, and remove a part of moisture content, the waste gas that comes out from the green pellets bed of material (6) enters in the petticoat pipe (9), then enter in the atmosphere, the green-ball that preheating is good, enter feed bin (3) bottom, have wide leather belt material distributing device (1) at feed bin (3), during work, wide belt on the wide leather belt material distributing device (1) moves forward, even area preheating, and good green-ball advances cloth to the roasting chassis, because the interior bed of material of feed bin (3) constantly descends, the pelletizing on the pre-hott bed (5) constantly moves down, and has formed a successive production process, for preventing that useless flue gas and dust from overflowing from the feed opening of feed bin (3), is provided with draught hood (2).

Claims

1, a kind of preheating device of raw briquet, form by green pellets cloth system, heat exchange system, hot wind supply system, it is characterized in that: the green pellets cloth system by shuttle-type distributor (8), green pellets fall snubber (7), snubber cleaner (10) is formed, heat exchange system is made up of petticoat pipe (9), feed bin (3), draught hood (2), pre-hott bed (5), wide leather belt material distributing device (1), and the hot wind supply system is made up of hot blast jet pipe (4), thermopair (11), cold wind mixing wind tube (12).

2, preheating device of raw briquet according to claim 1, it is characterized in that: the shell that is connected into heat exchange system by the feed bin (3) of orthogonal petticoat pipe (9) and last rectangle inferior pyramidal under the shape of last garden by flange, pre-hott bed (5) is to calculate bar by many to be placed on along the axis direction, on the skeleton of center protrusion, form the double inclined plane porous bed surface of center protrusion (5) by hot gas.Pre-hott bed (5) skeletal fixation is in the middle and upper part of feed bin (3), rib formula distributor (8) is positioned on the axis on pre-hott bed (5) top, the hot blast jet pipe (4) of heat exchange system is positioned on pre-hott bed (5) axis, bottom, draught hood (2) is positioned at the outlet periphery, lower end of feed bin (3), and wide leather belt material distributing device (1) is positioned at feed bin (3) outlet lower end.

3, according to the described preheating device of raw briquet of claim 2, it is characterized in that: two inclined-planes of pre-hott bed (5) can equate with the natural angle of rest (repose) of the green pellets of wanting preheating with the angle of horizontal plane or be close, and can in 30 °～50 °, adjust, two bevel edges of pre-hott bed (5) are from the distance 〉=100mm of feed bin (3) wall.