KR20030032390A - Molten slag sensible heat recovery system in blast furnace - Google Patents

Abstract

PURPOSE: A sensible heat recovering system of molten slag in blast furnace is provided to effectively recover sensible heat and waste heat of high temperature molten slag that are emitted without recovery and reduce environmental problems compared with a conventional granulation facility. CONSTITUTION: The sensible heat recovering system of molten slag in blast furnace comprises a blast furnace molten slag atomization apparatus (A) for atomizing molten slag injected after being generated from the blast furnace in the high temperature state; a pipeline(109) which is constructed in a way that heat is transferred to a heat exchanger(108) connected to the pipeline(109) as the fallen particulate is being naturally transferred along the inclined lower surface after particulate of slag is fallen down; a direct heat exchange unit(111) into which the particulate of slag fallen down the lower part of the pipeline(109) is flown to be direct contact heat exchanged with air blown from the lower part to the upper part; a particle separator(113) for emitting the air introduced from the direct heat exchange unit(111) to the upper side and separation discharging the particulate after transferring heat to a heat exchanger(114) by dropping the particulate to the lower side; a heat exchange chamber(118) for releasing the air after transferring heat to a heat exchanger(119) inside the heat exchange chamber(118) from high temperature air introduced from the particle separator(113); a blower(116) for circulating the air released from the heat exchange chamber(118) to the direct heat exchange unit(111); and an electricity generating cycle system (B) for continuously generating electricity by circulating the operating fluid again after generating electricity by receiving operating fluid of high temperature and high pressure from the heat exchangers(114,108) and the heat exchanger(119).

Description

Molten SLAG SENSIBLE HEAT RECOVERY SYSTEM IN BLAST FURNACE

The present invention relates to a blast furnace molten slag sensible heat recovery system, in a molten slag crushing facility of a steel mill blast furnace, by atomizing the molten slag into a form capable of high temperature heat recovery, by using the atomized molten slag as a heat source of the power generation cycle and discharged The present invention relates to a sensible heat recovery system for blast furnace molten slag that enables efficient recovery of sensible heat and arrangement of hot molten slag that is not recovered.

1 is a schematic diagram of a conventional blast furnace molten slag hydration system, and illustrates a system configuration of a conventional hydrocracking installation used to hydrolyze high temperature molten slag (1500 ° C.) generated in a blast furnace.

The hot molten slag 10 is atomized by the sprayed cooling water 51 and injected into the stirring vessel 50, and the steam 52 is discharged to the upper portion of the stirring vessel, and the atomized slag of about 90 ° C. accumulated in the lower portion of the stirring vessel is accumulated. The particles are transferred to the dryer 55 by the slurry pump 53 so that the slag fine particles are separated into the hopper bottom of the dryer 55, and the hot water is separated and recovered and stored in a water reservoir 57, and then, the cooling tower ( 59) after being cooled to about 60 ° C., and then supplied to the cooling spray device for molten slag crushing by the supply pump 61 to circulate.

Reference numeral 63, which is not described in FIG. 1, is a granular pump, 65 is an agitator pump, 67 is a sump pump, 69 is a settling box, and 71 is a booster. A booster pump is shown, respectively.

However, in the conventional molten slag hydration process, there is a problem that the recovery of the array generated through the sensible heat and the process possessed by the hot molten slag is hardly made, and thus inefficient in terms of energy use.

In addition, since the atomization is achieved by the cooling water, there is a problem in that the amount of water used is excessive (30Nm ³ / min is used in the system in which the applicant is currently operating), and thus a very large amount of water is consumed by evaporation. Therefore, the heat loss was also a problem.

In consideration of this problem, it has been attempted to use the water (about 90 ℃) used in the above process as a heat source of the power generation system, but the heat efficiency of the system is very low because the temperature of the heat source is a medium-low temperature There is a problem that the economy is falling.

The present invention has been made in view of the above problems, in a molten slag crushing facility of a steelworks blast furnace, the molten slag is atomized in a form capable of high temperature heat recovery, and discharged after using the atomized molten slag as a heat source of the power generation cycle It is an object of the present invention to provide a blast furnace molten slag sensible heat recovery system capable of efficiently recovering the sensible heat and arrangement of the hot molten slag that is not recovered.

1 is a block diagram of a conventional blast furnace molten slag hydration system,

2 is a block diagram of the blast furnace molten slag sensible heat recovery system according to the present invention,

3 is a cross-sectional configuration diagram showing in detail the blast furnace molten slag atomization device (A) according to the present invention;

4 is a perspective view showing the blast furnace molten slag atomization device (A) portion according to the present invention in more detail.

to be.

<Description of Symbols for Main Parts of Drawings>

10: molten slag 101: molten slag gutter

102: molten slag reservoir 103: accelerated drum

104: coolant nozzle 105: impingement wall

106: piping loop (for cooling water) 107: pump (for cooling water)

108,114,119: heat exchanger 109: transport pipe

110: by-pass 111: direct heat exchanger

113: particle separator 115,117 connection pipe

116: blower 118: heat exchange chamber (chamber)

120 turbine 121 condenser

122: pump (for working fluid) A: blast furnace molten slag atomization device

B: Cycle system for power generation

The present invention for achieving the above object, the hot molten slag generated in the blast furnace and injected along the gutter 101 is stored and discharged in the molten slag reservoir 102, the discharged molten slag acceleration drum Accelerated by the rotating surface of 103 to impart kinetic momentum in the tangential direction, to cause the accelerated slag to collide with and collide with the collision wall 105, between the acceleration drum 103 and the collision wall 105 A blast furnace molten slag atomizing device (A) having a coolant nozzle (104) for freely dropping cooling water on the fluidized bed of the granular material to atomize the molten slag to a high temperature state;

A transport pipe 109 which is formed to be naturally transported along the inclined lower surface after the particles reflected by the impingement wall 105 fall, and is configured to transfer heat of the particles to the heat exchanger 108 connected thereto;

Particles dropped to the lower portion of the transport pipe 109 is introduced through the lower portion of the side, and discharged through the upper portion of the side by the pressure of the air blown from the lower portion to the upper portion, the direct contact heat exchange between the air and the particulate is formed A direct heat exchanger (111);

Particles and air are introduced from the direct contact heat exchanger 111, light air is discharged to the top, and relatively heavy particles are dropped to the bottom to transfer heat to the heat exchanger 114, and then separated and discharged at a low temperature. A particle separator 113;

A heat exchange chamber 118 passing heat through the hot air introduced from the particle separator 113 to transfer heat to the heat exchanger 119 installed therein, and then discharging the heat downward;

A blower (116) for supplying air discharged from the heat exchange chamber (118) to the direct heat exchange device (111);

The working fluid evaporated while sequentially passing through the heat exchanger 114 and 118 and the working fluid evaporated while passing through the heat exchanger 119 are supplied to the turbine 120 to generate power, and then the condenser 121. Condensed in, characterized in that configured to include a power generation cycle system (B) formed to be separately supplied to the heat exchanger 114 and the heat exchanger 119 again by the pump 122.

Further, in the present invention, the blast furnace molten slag atomizing device (A) stores the hot molten slag 10 generated in the blast furnace and injected into the upper portion along the gutter, and the molten slag 10 by using an upper and lower pressure difference. ) Is continuously discharged through the lower outlet, and has a molten slag flow rate control door (102a) for adjusting the size of the lower outlet in the up and down opening and closing, molten slag reservoir lower portion 102b inclined downward toward the lower outlet side. A molten slag reservoir (102) having an inner bottom surface and having a guide vane (102c) for separating and discharging molten slag at a rear end of the lower outlet;

An acceleration drum 103 installed below the rear end of the guide slab for discharging and discharging the molten slag, for accelerating the discharged molten slag 10 by its rotating surface to impart kinetic momentum in a tangential direction;

A collision wall (105) installed to collide with the accelerated slag and reflect it, but to reflect the slag off and to be discharged to the transport pipe (109);

Located in the upper portion of the flow between the acceleration drum 105 and the impingement wall 105, the cooling water is rapidly cooled by contacting the molten slag freely dropping and passing through the pump 107 and the pipe loop 106 It characterized in that it comprises a cooling water nozzle 104 is circulated supply through.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

2 is a configuration diagram of the blast furnace molten slag sensitization recovery system according to the present invention, Figure 3 is a cross-sectional view showing in detail the blast furnace molten slag atomization device (A) according to the present invention, Figure 4 is a blast furnace according to the present invention It is a perspective view which showed the molten slag atomization apparatus A part in detail.

The blast furnace molten slag sensation recovery system according to the present invention, the blast furnace molten slag atomization device (A), the transport pipe 109, direct heat exchange device 111, particle separator 113, heat exchange chamber 118, blower 116 ), The cycle system for power generation (B) is composed of the main components.

The molten slag of high temperature (1550 ° C.), which is separated from the molten iron due to the difference in specific gravity in the blast furnace, is injected into the molten slag collector 102 along the molten slag runner 101 and the molten slag reservoir 102 The molten slag falling from the lower outlet of the c) collides with the acceleration drum 103 located below.

At this time, the molten slag that is in contact with the surface of the acceleration drum 103 is subjected to the momentum of movement in the tangential direction of the acceleration drum 103 by the rotation of the acceleration drum 103, thereby causing the flow in the direction of the collision wall 105 do.

On the other hand, in case the acceleration drum 103 is troubled due to a cooling problem, a coolant injection nozzle (not shown) is installed under the molten slag reservoir 102, and slag is impinged by the momentum of the sprayed coolant. It is preferably configured to impinge directly onto 105.

The molten slag is rapidly cooled by the contact with the coolant (approximately 60 ° C.) falling from the coolant nozzle 104 located in the fluidized bed between the acceleration drum 103 and the impingement wall 105, thereby increasing the vitrification rate of the slag. Is increased. In other words, since rapid cooling does not give time for the internal particles of slag to sufficiently crystallize, the vitrification rate of the fine slag (80% or more) is increased, thereby improving the affinity with cement. As it can be used as roadbed or concrete extender, it is possible to increase the added value of the wood slag itself.

The free-falling coolant is circulated along the pipe loop 106 by the pump 107, and some of the lost coolant is supplied by an external auxiliary line (not shown).

The slag falling through vitrification and parabolic movement becomes primary atomization by collision with the collision wall 105, and the secondary atomization proceeds as it falls on the particle transport pipe 109 at a temperature of about 900 ° C. do.

On the other hand, the lower surface of the transport pipe 109 is formed to be inclined downward, is configured so that the slag particles are naturally transported inside the transport pipe 109 as the secondary atomization proceeds.

The slag particles transported as described above fall down to the lower portion of the transport pipe 109 and are preheated by the heat exchanger 114 at the front end, and the working fluid of the power generation cycle system B introduced through the connection pipe 115 is transferred to the heat exchanger. It is evaporated through 108, and flows into the direct heat exchanger 111 of the rear stage. At this time, since the slag particles may block the lower outlet of the transport pipe 109 due to the pressure of the air supplied by the blower 116, it is preferable to prevent this by placing a bypass 110 line.

On the other hand, the air velocity in the direct heat exchanger 111 supplied by the blower 116 should be greater than the critical velocity of the fluidized bed velocity to enable engineering transport.

After direct contact heat exchange between the air supplied by the blower 116 and the slag particles is carried out, the slag particles and the air pass through the particle separator 113 at a later stage, wherein light air is supplied to the heat exchange chamber 118. Relatively heavy slag particles fall to the lower portion of the particle separator 113 to be separated and discharged in a low temperature state through the heat exchanger 114 serving as a preheater of the working fluid cycle system B.

The hot air supplied to the heat exchange chamber 118 is heat-exchanged and cooled by the heat exchanger 119 serving as a preheater, an evaporator and a superheater of the power generation cycle system B, and the lower portion of the heat exchange chamber 118 in a low temperature state. The process is repeated by the blower 116 to be discharged to and discharged again.

The working fluid of the cycle system (B) for power generation passes through the turbine 120 in a superheated state at high temperature and high pressure by the heat exchanger 119 and the heat exchanger 114,108, and at this time, generates power while undergoing a thermodynamic change to a low temperature and low pressure state. After the condensation in the condenser 121, the working fluid pump 122 circulates the power generation cycle system B again.

In the system of the present invention, a shell & tube type heat exchanger generally used as the heat exchanger 108, 114 and 119 may be used, but is not necessarily limited to this type of heat exchanger, and may have an equivalent effect. Other types of heat exchangers may of course be used. In addition, the cycle system (B) for power generation may use steam as the working fluid, or an organic refrigerant having a similar effect may be used.

By the above system, the sensible heat of the hot molten slag can be recovered efficiently and high quality slag fine particles can be produced.

On the other hand, the blast furnace molten slag atomization device (A) according to the present invention will be described in detail as follows.

The blast furnace molten slag atomization apparatus according to the present invention comprises a molten slag reservoir 102, an acceleration drum 103, an impingement wall 105, and a coolant nozzle 104 as main components.

The molten slag 10 having a high temperature (about 1550 ° C.), which is separated from the molten iron due to the difference in specific gravity in the blast furnace, is injected into the molten slag reservoir 102 along the gutter, and the upper and lower parts from the lower outlet of the molten slag reservoir 102. The molten slag 10 stored as described above is discharged by the pressure difference (gravity). At this time, the molten slag discharged from the molten slag reservoir 102 is flow rate controlled by the molten slag flow rate control door 102a which is operated in the vertical direction so that the molten slag 10 discharged intermittently from the blast furnace can be continuously supplied. It is configured to be.

On the other hand, the molten slag reservoir lower portion 102b constituting the inner bottom surface of the molten slag reservoir 102 is configured to be inclined downward toward the lower outlet side, it is easier to discharge molten slag, the horizontal direction of the molten slag discharged The speed was increased to increase the amount of momentum exchange with the impingement wall 105, so that the atomization rate was further increased.

At the rear end of the lower outlet of the molten slag reservoir 102, a guide vane 102c for separating and discharging molten slag is installed to promote atomization of the molten slag.

As described above, the molten slag discharged through the lower discharge port and the guide vane 102c for discharging and separating the molten slag is brought into contact with the surface of the acceleration drum 103 installed at the lower rear end of the guide vane 102c for the molten slag separation and discharging. Then, by the rotation of the acceleration drum 103, the moment of motion is applied in the tangential direction to increase the flow in the direction of the impingement wall 105.

On the surface of the acceleration drum 103, a plurality of disc- or protrusion-shaped baffles 103a are installed along the axial direction to generate turbulence in the flow of the molten slag, through which instability of the molten slag flows. Causing it to promote atomization.

On the other hand, the molten slag applied with the kinetic momentum in the tangential direction by the rotation of the acceleration drum 103 is located in the upper portion of the flow between the acceleration drum 103 and the collision wall 105 during the flow in the direction of the collision wall 105. In contact with the cooling water (about 60 ℃) falling from the cooling water nozzle 104 is to be rapidly cooled.

At this time, the free-falling coolant is circulated along the pipe loop 106 by the pump 107, and some of the lost coolant is replenished by an external auxiliary line (not shown) as described above.

Thereafter, the molten slag is atomized by the collision with the impingement wall 18, wherein the temperature of the fine particles is about 900 ℃, and is discharged to the post-process through the fine particle transport pipe 109.

Such blast furnace molten slag sensation recovery system of the present invention, in the molten slag crushing facility of the blast furnace of the steel mill, the molten slag is atomized into a form capable of high temperature heat recovery, by using the atomized molten slag as a heat source of the power generation cycle, It provides the effect of efficiently recovering the sensible heat and arrangement of the hot molten slag that is not recovered, and reduces the environmental problems compared to the conventional crushed equipment.

It also provides the effect of increasing the added value of the handmade slag itself by increasing the vitrification rate of the slag and improving its affinity with cement.

Claims (2)

The hot molten slag generated in the blast furnace and injected along the trough 101 is stored and discharged into the molten slag reservoir 102, and the discharged molten slag is accelerated by the rotating surface of the acceleration drum 103 to tangentially Direction to impart movement momentum, the accelerated slag impinges on the impact wall 105 and is reflected therein, and a coolant nozzle freely dropping the coolant on the fluidized bed between the acceleration drum 103 and the impact wall 105 ( A blast furnace molten slag atomization device (A) having 104) for atomizing molten slag to a high temperature state; A transport pipe 109 which is formed to be naturally transported along the inclined lower surface after the particles reflected by the impingement wall 105 fall, and is configured to transfer heat of the particles to the heat exchanger 108 connected thereto; Particles dropped to the lower portion of the transport pipe 109 is introduced through the lower portion of the side, and discharged through the upper portion of the side by the pressure of the air blown from the lower portion to the upper portion, the direct contact heat exchange between the air and the particulate is formed A direct heat exchanger (111); Particles and air are introduced from the direct contact heat exchanger 111, light air is discharged to the top, and relatively heavy particles are dropped to the bottom to transfer heat to the heat exchanger 114, and then separated and discharged at a low temperature. A particle separator 113; A heat exchange chamber 118 passing heat through the hot air introduced from the particle separator 113 to transfer heat to the heat exchanger 119 installed therein, and then discharging the heat downward; A blower (116) for supplying air discharged from the heat exchange chamber (118) to the direct heat exchange device (111); The working fluid evaporated while sequentially passing through the heat exchanger 114 and 118 and the working fluid evaporated while passing through the heat exchanger 119 are supplied to the turbine 120 to generate power, and then the condenser 121. The condensation at the blast furnace molten slag sensible heat recovery system, characterized in that it comprises a cycle system (B) for power generation formed to be separately supplied to the heat exchanger (114) and the heat exchanger (119) again by the pump (122). The blast furnace molten slag atomization device (A) according to claim 1, Store the hot molten slag 10 generated in the blast furnace and injected into the upper portion along the gutter, and continuously discharge the molten slag 10 through the lower outlet using the upper and lower pressure difference, the lower outlet in the vertical opening and closing And a molten slag flow rate control door 102a for controlling the size of the molten slag, and having a molten slag reservoir lower portion 102b inclined downward toward the lower outlet side as an inner bottom surface, and separating molten slag at the rear end of the lower outlet port. A molten slag reservoir (102) having a discharge guide vane (102c); An acceleration drum 103 installed below the rear end of the guide slab for discharging and discharging the molten slag, for accelerating the discharged molten slag 10 by its rotating surface to impart kinetic momentum in a tangential direction; A collision wall (105) installed to collide with the accelerated slag and reflect it, but to reflect the slag off and to be discharged to the transport pipe (109); Located in the upper portion of the flow between the acceleration drum 105 and the impingement wall 105, the cooling water is rapidly cooled by contacting the molten slag freely dropping and passing through the pump 107 and the pipe loop 106 The blast furnace molten slag sensible heat recovery system, characterized in that it comprises a cooling water nozzle 104 is circulated supply through.