A continuous slag slow cooling waste heat recovery system and method

Abstract

The application discloses a continuous molten slag slow cooling waste heat recovery system and method, and belongs to the non-ferrous metal smelting technical field.The continuous molten slag slow cooling waste heat recovery system and method adopt an automatic demolding system, a nitrogen circulating air system and a boiler steam-water heat exchange system, and simultaneously realize the effects of continuous molten slag slow cooling and waste heat recovery.In addition, the nitrogen circulating air system can ensure that no oxidation reaction occurs in the high-temperature zone of the molten slag, reduces black smoke, can reduce the circulating air to a lower temperature through a water-cooled heat exchanger without dew condensation, and can reduce the temperature of the ash slag to a temperature lower than the dew point temperature of water vapor, so that the heat efficiency of the whole system is improved, and no heavy metal sewage is generated.Furthermore, the automatic demolding system overcomes the problem that the traditional slag ladle has a large volume and cannot be directly crushed, and manual coarse crushing is required, and the manual operation risk is large.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of non-ferrous metal smelting, and particularly relates to a continuous smelt slag slow cooling waste heat recovery system and method. BACKGROUND

[0002] In the field of non-ferrous metal smelting, the purpose of fire smelting is to extract valuable metals from minerals. After the valuable metals are extracted from the minerals by smelting, a large amount of high-temperature smelt slag needs to be discharged. There are two kinds of high-temperature smelt slag treatment technologies in existing factories: one technology is to perform water quenching treatment on the smelt slag, that is, to disperse and cool the high-temperature smelt slag flowing out of a chute by using cold water with a certain pressure and flow rate, and then to cool the water by using a cooling tower; the other technology is to perform slow cooling on the smelt slag after traditional slag ladle slag receiving, that is, to perform slow cooling on the smelt slag in the slag ladle, usually for about 24 hours under natural air conditions, so as to promote the growth of valuable metal grains, and then to perform water spraying cooling after the smelt slag in the slag ladle is completely solidified, so as to accelerate the cooling speed and improve the slag ladle turnover rate. Both of the two kinds of high-temperature smelt slag treatment technologies in existing factories do not recover and utilize the waste heat of the smelt slag, and at the same time, a large amount of sewage containing heavy metals and unorganized steam diffusion problems are caused, which is not conducive to clean and green production.

[0003] For the slow cooling waste heat recovery technology of high-temperature smelt slag, the same industry is developing and researching a technology of water cooling after tunnel kiln or hot air room heat exchange. The technology uses traditional slag ladles to transport smelt slag for heat exchange in the tunnel kiln or hot air room, and performs water cooling after the smelt slag is solidified. The technology has the problem of low waste heat utilization rate. Other similar technologies also use traditional slag ladles to perform slow cooling on smelt slag. Manual intervention is needed to pour the traditional slag ladles, and the traditional slag ladles have large volume and cannot be directly crushed. Related machinery needs to be used for coarse crushing to meet the feeding requirements of the crusher.

[0004] Therefore, how to realize continuous slow cooling of high-temperature smelt slag and synchronous efficient recovery of waste heat is a problem to be solved in the industry. SUMMARY

[0005] In view of the above-mentioned defects of the prior art, the application provides a continuous smelt slag slow cooling waste heat recovery system and method.

[0006] To achieve the above-mentioned purpose, the technical scheme adopted by the application is as follows: a continuous smelt slag slow cooling waste heat recovery system comprises an automatic demolding chain plate system 3, a membrane wall chain plate flue 4, a water-cooled crusher, a water-cooled screw conveyor 8, a water-cooled slag machine 9, an air chamber 10, a fluidized furnace chamber 11, a cyclone separator 12, a convection tube bundle 13, an economizer 14, a water-cooled heat exchanger 15, a bag-type dust collector 16, and a desalted water or soft water tank.

[0007] The automatic demolding chain plate system 3 is located in the membrane wall chain plate flue 4; the membrane wall chain plate flue 4 is connected with the water-cooled crusher; the water-cooled crusher is connected with the first inlet below the fluidized hearth 11 through the water-cooled screw conveyor 8; the upper outlet of the fluidized hearth 11 is connected with the inlet above the cyclone separator 12, and the bottom outlet of the cyclone separator 12 is connected with the second inlet below the fluidized hearth 11; the bottom of the fluidized hearth 11 is connected with the air chamber 10 and the slag cooler 9 respectively; the top outlet of the cyclone separator 12 is connected with the convection tube bundle 13, the economizer 14, the water-cooled heat exchanger 15 and the bag-type dust collector 16 in sequence; the bag-type dust collector 16 is connected with the inlet of the membrane wall chain plate flue 4; and the outlet of the membrane wall chain plate flue 4 is connected with the air chamber 10.

[0008] The desalted water or soft water tank is connected with the water inlet of the water-cooled heat exchanger 15, the water inlet of the water-cooled screw conveyor 8 and the deaerator 18 in sequence; and the desalted water or soft water tank is connected with the water inlet of the water-cooled crusher, the water inlet of the slag cooler 9 and the deaerator 18 in sequence.

[0009] The deaerator 18 is connected with the water inlet of the economizer 14, the water outlet of the economizer 14 is connected with the steam drum 17, the steam drum 17 is connected with the membrane water-cooled wall of the membrane wall chain plate flue 4, the air chamber 10 and the fluidized hearth 11 and the convection tube bundle 13 through the downcomer, and then is connected with the steam drum 17 through the riser.

[0010] As a preferred embodiment of the present application, the automatic demolding chain plate system 3 comprises a first driving sprocket 301, a slag receiving disc 303, a slag disc thimble 304, a rotating chain 305, a second driving sprocket 306 and a demolding rolling ring 307; the rotating chain 305 is driven to rotate by the first driving sprocket 301 and the second driving sprocket 306 arranged at the head and tail ends respectively; the demolding rolling ring 307 is arranged on the second driving sprocket 306 and rotates integrally with the driving sprocket as a coaxial cylinder between the second driving sprocket teeth; and the slag receiving disc 303 is connected with the rotating chain 305.

[0011] As a preferred embodiment of the present application, the automatic demolding chain plate system 3 further comprises a slag receiving disc hinge point 302, and the slag receiving disc 303 is hinged with the rotating chain 305 through the slag receiving disc hinge point 302 arranged at the bottom.

[0012] As a preferred embodiment of the present application, the slag receiving disc 303 is provided with a hole at the middle position of the bottom, the slag disc thimble 304 is precisely matched with the hole at the bottom of the slag receiving disc 303, the slag disc thimble 304 is freely movable in the hole, and the bottom of the slag receiving disc 303 is sealed after the slag disc thimble is closed with the slag receiving disc 303.

[0013] As a preferred embodiment of the present application, when the slag disc ejector 304 is above the second driving sprocket 306, the slag disc ejector 304 contacts the demolding roller 307, and under the rotation of the demolding roller 307 and the second driving sprocket 306, the slag disc ejector 304 is lifted to realize automatic demolding of the slag disc 303. When the slag disc 303 rotates to be directly below the second driving sprocket 306, under the double action of the slag disc ejector 304 and the self-weight of the solidified slag, the solidified slag after the slag disc 303 is turned over is automatically demolded.

[0014] As a preferred embodiment of the present application, the slag disc 303 is uniformly distributed on the rotating chain 305.

[0015] As a preferred embodiment of the present application, the continuous molten slag slow cooling waste heat recovery system further comprises a rotating intermediate ladle 1 and a slag chute 2. The rotating intermediate ladle 1 is arranged between the metallurgical furnace slag outlet and the slag chute 2. One end of the slag chute 2 is below the rotating intermediate ladle 1, and the other end is above the automatic demolding chain plate system 3. The bottom of the rotating intermediate ladle 1 is provided with an electric rotating motor. The electric rotating motor, the first driving sprocket 301 of the automatic demolding chain plate system 3, and the driving motor of the second driving sprocket 306 are all servo motors. The rotation of the rotating intermediate ladle matches the slag receiving of the slag disc 303, that is, when each slag disc 303 is stopped at the slag chute slag falling position, the molten slag in the rotating intermediate ladle 1 can be rotated and poured into the slag disc. When the slag disc is walking, the rotating intermediate ladle is tilted back to the original position without pouring slag, so that the molten slag flows into the slag disc in an orderly manner. After the slag disc 303 completes demolding of the slag ingot directly below the second driving sprocket 306, it continues to circulate forward under the second driving sprocket 306. When it reaches above the first driving sprocket 301, the slag disc ejector 304 automatically falls under the action of its own weight, realizing automatic sealing of the bottom of the slag disc. When it reaches the third to fifth slag discs 303 above the first driving sprocket 301, it starts to circulate and receive molten slag, and the slow cooling and demolding are repeated.

[0016] As a preferred embodiment of the present application, the membrane wall chain plate flue 4 is sealed by the upper and lower and left and right and front and back six surfaces of the membrane water cooling wall structure.

[0017] As a preferred embodiment of the present application, the water-cooled crusher comprises a first water-cooled crusher 6 and a second water-cooled crusher 7, and the membrane wall chain plate flue 4 is connected with the slag hopper 5, the first water-cooled crusher 6 and the second water-cooled crusher 7 in sequence.

[0018] As a preferred embodiment of the present application, four sets of parallel automatic demolding chain plate systems 3 are arranged in the membrane wall chain plate flue 4. The four sets of parallel automatic demolding chain plate systems 3 are realized synchronous meshing rotation and movement by setting four sprockets with the same shape and size as the first driving sprocket 301 and the second driving sprocket 306.

[0019] As a preferred embodiment of the present application, the continuous slag slow cooling waste heat recovery system further comprises a slag bucket 5 connected with the membrane wall chain plate flue 4 and located below the second driving sprocket 306, and the slag bucket 5 is spliced into a funnel shape by a tube sheet type water cooling wall.

[0020] As a preferred embodiment of the present application, the bag-type dust collector 16 is connected with the inlet of the membrane wall chain plate flue 4 through a pipeline provided with a first circulating fan 19, and the outlet of the membrane wall chain plate flue 4 is connected with the air chamber 10 through a pipeline provided with a second circulating fan 20.

[0021] As a preferred embodiment of the present application, a connecting pipeline is provided between the outlet of the second circulating fan 20 and the air chamber 10 to the bottom of the cyclone separator 12.

[0022] As a preferred embodiment of the present application, the water cooling heat exchanger 15 and the economizer 14 are of a tube type heat exchanger structure, the water cooling screw conveyor 8, the second water cooling crusher 7 and the first water cooling crusher 6 are of a plate type and tube type heat exchange structure, and the slag cooler 9 is of a cylinder type and multi-tube type heat exchange structure.

[0023] As a preferred embodiment of the present application, the desalted water or soft water tank is connected with the water inlet of the water cooling heat exchanger 15 and the water inlet of the second water cooling crusher 7 through a first water pump 21 respectively, and the deaerator 18 is connected with the water inlet of the economizer 14 through a second water pump 22.

[0024] A continuous slag slow cooling waste heat recovery method, comprising the following steps:

[0025] (1) The high-temperature melt discharged from the slagging port of the pyrometallurgical furnace is introduced into the rotating intermediate slag ladle 1, and then introduced into the slag receiving disc 303 through the slag chute 2, the slag receiving disc 303 rotates with the rotating chain 305, and when the slag receiving disc 303 rotates to the position directly above the second driving sprocket 306, the slag receiving disc ejector pin 304 contacts the demolding roller ring 307, and the slag receiving disc ejector pin 304 is lifted up; when the slag receiving disc 303 rotates to the position directly below the second driving sprocket 306, the slag receiving disc 303 is turned over, and the solidified slag is automatically demolded;

[0026] (2) The solidified slag after falling off is placed in the slag hopper 5, and then is crushed into slag particles after passing through the first water-cooled crusher 6 and the second water-cooled crusher 7, and the slag particles are transported to the fluidized hearth 11 by the water-cooled screw conveyor 8, the nitrogen circulating air from the membrane wall chain plate flue 4 head enters the fluidized hearth 11 through the air chamber 10, the slag particles in the fluidized hearth 11 present a fluidized state, and heat exchange is performed with the nitrogen circulating air, the slag particles are cooled, and the nitrogen circulating air is heated; the nitrogen circulating air with part of the slag particles enters the cyclone separator 12, and large-particle slag particles are settled to the bottom by rotation, and fine-particle slag particles and the nitrogen circulating air sequentially pass through the convection tube bundle 13, the coal economizer 14 and the water-cooled heat exchanger 15 from the top of the cyclone separator 12, the temperature of the nitrogen circulating air is lowered, and then the nitrogen circulating air enters the bag-type dust collector 16 for purification and dust removal;

[0027] (3) The nitrogen circulating air after dust removal by the bag-type dust collector 16 enters the membrane wall chain plate flue 4 tail, and moves reversely with the slag receiving disc 303 containing the high-temperature melt, the high-temperature slag in the slag receiving disc 303 is cooled into solid slag, and the nitrogen circulating air flows out at the membrane wall chain plate flue 4 head and enters the air chamber 10; at the same time, the water in the membrane water-cooled wall tube of the membrane wall chain plate flue 4 is heated into a steam-water mixture and enters the steam drum 17;

[0028] (4) The water in the desalted water tank or soft water tank is output in two ways, the first way is to first enter the water inlet of the water-cooled wall tube of the water-cooled heat exchanger 15, enter the water outlet of the water-cooled wall tube of the water-cooled heat exchanger 15, enter the water inlet of the water-cooled wall tube of the water-cooled screw conveyor 8, and enter the deaerator 18 through the water outlet of the water-cooled wall tube of the water-cooled screw conveyor 8; the second way is to first enter the water inlet of the water-cooled wall tube of the second water-cooled crusher 7, enter the water outlet of the water-cooled wall tube of the second water-cooled crusher 7, enter the water inlet of the water-cooled wall tube of the first water-cooled crusher 6, enter the water inlet of the water-cooled wall tube of the slag cooler 9 through the water outlet of the water-cooled wall tube of the first water-cooled crusher 6, and enter the deaerator 18 through the water outlet of the water-cooled wall tube of the slag cooler 9;

[0029] (5) The water in the deaerator 18 is transported to the water inlet of the coal economizer 14, and then enters the steam drum 17 through the water outlet of the coal economizer 14, the water in the steam drum 17 enters the membrane water-cooled wall of the membrane wall chain plate flue 4, the air chamber 10, the fluidized hearth 11 and the water-cooled wall tube of the convection tube bundle 13 through the downcomer respectively, the water in the membrane water-cooled wall of the membrane wall chain plate flue 4, the air chamber 10, the fluidized hearth 11 and the water-cooled wall tube of the convection tube bundle 13 is heated by the high-temperature nitrogen circulating air and returns to the steam drum 17 through the riser, and steam is generated after steam-water separation in the steam drum 17, and the steam is used for power generation or heat supply.

[0030] Compared with the prior art, the continuous slag slow cooling and waste heat recovery system and method has the advantages that the automatic demolding system, the nitrogen circulating air system and the boiler steam-water heat exchange system are adopted, and the effects of continuous slag slow cooling and waste heat recovery are realized. In non-ferrous metallurgical plants, oxygen-enriched smelting is generally adopted, a large amount of nitrogen is generated in the oxygen production process, and most of the nitrogen is discharged, so the nitrogen is very convenient to obtain in the non-ferrous metallurgical plant without additional investment. Therefore, the nitrogen circulating air system is adopted, on the one hand, the oxidation reaction in the high-temperature zone of the slag can be prevented, and the black smoke is reduced, and on the other hand, the circulating air can be reduced to a lower temperature through the water-cooled heat exchanger without dewing, and the temperature of the ash slag can be reduced to a temperature lower than the dew point temperature of the water vapor, so that the heat efficiency of the whole system is improved, and no heavy metal sewage is generated. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The continuous slag slow cooling and waste heat recovery system.

[0032] Figure 2 The nitrogen circulating system diagram of the continuous slag slow cooling and waste heat recovery system.

[0033] Figure 3 The boiler steam-water system diagram of the continuous slag slow cooling and waste heat recovery system.

[0034] Figure 4 The structure diagram of the automatic demolding chain plate system, wherein figure (a) is the structure front view of the automatic demolding chain plate system, and figure (b) is the structure top view of the automatic demolding chain plate system.

[0035] Figure 5 The slag receiving disc structure schematic diagram of the application, wherein figure (a) is the front view of the slag receiving disc, and figure (b) is the top view of the slag receiving disc.

[0036] In the figure, 1-rotating intermediate ladle; 2-slag chute; 3-automatic demolding chain plate system; 4-membrane wall chain plate flue; 5-slag hopper; 6-first water-cooled crusher; 7-second water-cooled crusher; 8-water-cooled screw conveyor; 9-slag cooler; 10-air chamber; 11-fluidized furnace; 12-cyclone separator; 13-convection tube bundle; 14-economizer; 15-water-cooled heat exchanger; 16-bag-type dust collector; 17-steam drum; 18-deaerator; 19-first circulating fan; 20-second circulating fan; 21-first water pump; 22-second water pump; 301-first driving sprocket; 302-slag receiving disc hinge point; 303-slag receiving disc; 304-slag disc thimble; 305-rotating chain; 306-second driving sprocket; 307-demolding roller ring; 308-bearing sprocket. DETAILED DESCRIPTION

[0037] For better illustrating the purpose, technical scheme and advantages of the present application, the present application will be further described in combination with specific examples.

[0038] Example 1

[0039] A continuous slag slow cooling waste heat recovery system comprises:

[0040] The rotating intermediate ladle 1, the slag chute 2, the automatic demolding chain plate system 3, the membrane wall chain plate flue 4, the slag bucket 5, the first water-cooled crusher 6, the second water-cooled crusher 7, the water-cooled screw conveyor 8, the slag cooler 9, the air chamber 10, the fluidized hearth 11, the cyclone separator 12, the convection tube bundle 13, the coal economizer 14, the water-cooled heat exchanger 15, the bag-type dust collector 16, the first circulating fan 19, the second circulating fan 20 and the desalted water or soft water tank.

[0041] The rotating intermediate ladle 1 is arranged between the slag discharge port of the metallurgical furnace and the slag chute 2, one end of the slag chute 2 is located below the rotating intermediate ladle 1, and the other end is located above the automatic demolding chain plate system 3. The bottom of the rotating intermediate ladle 1 is provided with an electric rotating motor, the electric rotating device motor and the driving motors of the first driving sprocket 301 and the second driving sprocket 306 of the automatic demolding chain plate system 3 are all servo motors, and the rotating intermediate ladle 1 is matched with the slag receiving disc 303 during rotation to receive slag, that is, when each slag receiving disc 303 stops rotating at the slag discharge port position of the slag chute 2, the molten slag in the rotating intermediate ladle 1 can be just rotated and poured into the slag receiving disc 303, and when the slag receiving disc 303 is walking, the rotating intermediate ladle 1 is tilted back to the original position without pouring slag, so that the molten slag flows into the slag receiving disc in an orderly manner.

[0042] The automatic demolding chain plate system 3 comprises a first driving sprocket 301, a slag receiving plate 303, a slag receiving plate pin 304, a rotating chain 305, a second driving sprocket 306 and a demolding ring 307; the rotating chain 305 is driven to rotate by the first driving sprocket 301 and the second driving sprocket 306 arranged at the head and tail ends of the rotating chain 305 respectively; a plurality of load bearing sprockets 308 can be arranged between the first driving sprocket 301 and the second driving sprocket 306 as needed to increase the load bearing performance of the rotating chain 305. The bottom of the slag receiving plate 303 is hinged to the rotating chain 305 by arranging a slag receiving plate hinge point 302; a hole is opened in the middle of the bottom of the slag receiving plate 303, the slag receiving plate pin 304 is precisely matched with the hole in the bottom of the slag receiving plate 303, the slag receiving plate pin 304 moves freely in the hole, and the slag receiving plate pin is sealed after closing with the slag receiving plate 303, without leakage of molten slag. The outer dimensions of the slag receiving plate 303 are strictly controlled to control the size of the slag ingot, so that the size of the slag ingot does not exceed the maximum feeding size of the first water-cooled crusher 6. The demolding ring 307 is arranged on the second driving sprocket 306, the demolding ring 307 is a coaxial cylinder between the second driving sprocket tooth ring, and rotates integrally with the driving sprocket; the high-temperature molten slag begins to flow into the slag receiving plate 303 above the first driving sprocket 301 on the rotating chain 305, the slag receiving plate 303 after receiving the high-temperature molten slag slowly walks forward under the action of the first driving sprocket 301, the second driving sprocket 306 and the rotating chain 305, during which the high-temperature melt in the slag receiving plate 303 slowly cools down, the cooling time of the molten slag is controlled by controlling the distance between the first conveying sprocket 301 and the second conveying sprocket 306, and the high-temperature molten slag reaches the front of the second driving sprocket 306 after completely solidifying; when the slag receiving plate 303 rotates to the above of the second driving sprocket 306, the slag receiving plate pin 304 arranged on the slag receiving plate 303 contacts the demolding ring 307, under the rotating action of the demolding ring 307 and the second driving sprocket 306, the slag receiving plate pin 304 is lifted up; then when the slag receiving plate 303 rotates to directly below the second driving sprocket 306, the solidified slag ingot after the slag receiving plate 303 is turned over is automatically demolded under the double action of the slag receiving plate pin 304 and the self-weight of the solidified slag ingot. After the slag receiving plate 303 completes the demolding of the slag ingot directly below the second driving sprocket 306, it continues to circulate and advance under the second driving sprocket 306, when it reaches above the first driving sprocket 301, the slag receiving plate pin 304 automatically falls down under the action of the self-weight, realizing the automatic sealing of the bottom of the slag receiving plate 303, and when it reaches the third slag receiving plate 303 position above the first driving sprocket 301, it begins to circulate and receive molten slag, and the slow cooling and demolding are circularly performed.

[0043] The membrane wall chain plate flue 4 is a long strip box-shaped structure, and the upper, lower, left, right, front and back six surfaces are all membrane water-cooled wall structures, which are combined to form a sealed membrane wall flue. The automatic demolding chain plate system 3 is supported and fixed on the steel frame outside the membrane wall chain plate flue 4 through the first driving sprocket 301, the second driving sprocket 306 and the bearing sprocket 308, and then the automatic demolding chain plate system 3 is fixed in the membrane wall chain plate flue 4. Four groups of parallel automatic demolding chain plate systems 3 are arranged in the membrane wall chain plate flue 4, and the four groups of parallel automatic demolding chain plate systems 3 are synchronously meshed and rotated and moved through the four sprockets of the same shape and size arranged on the first driving sprocket 301 and the second driving sprocket 306.

[0044] The membrane wall chain plate flue 4 is connected with the slag hopper 5 at the outlet below the second driving sprocket 306, the slag hopper 5 is spliced into a funnel shape by the tube plate type water-cooled wall, which can effectively reduce the mechanical damage of the membrane wall and also can temporarily store a certain amount of slag ingot. The slag hopper 5 is sequentially connected with the first water-cooled crusher 6 and the second water-cooled crusher 7; the second water-cooled crusher 7 is connected with the first inlet below the fluidized hearth 11 through the water-cooled screw conveyor 8. The size of the slag ingot is controlled by controlling the size of the slag receiving disc 303, and the size of the slag ingot is within the feeding size range of the first water-cooled crusher 6, so that the slag ingot is automatically dropped into the first water-cooled crusher 6 after being temporarily stored in the slag hopper 5, the slag ingot is crushed into slag particles of a certain particle size in the first water-cooled crusher 6, and then enters the second water-cooled crusher 7, and is further crushed into slag particles of smaller particle size, and then enters the water-cooled screw conveyor 8 and is conveyed to the fluidized hearth 11.

[0045] The bottom of the fluidized hearth 11 is connected with the air chamber 10 and the slag cooler 9; the upper outlet of the fluidized hearth 11 is connected with the upper part of the cyclone separator 12, the bottom outlet of the cyclone separator 12 is connected with the second inlet below the fluidized hearth 11 through the ash and slag pipe; the top outlet of the cyclone separator 12 is the flue gas outlet connected with the top inlet of the flue formed by the light furnace wall. The flue formed by the light furnace wall includes, from top to bottom, the convection tube bundle 13, the economizer 14 and the water-cooled heat exchanger 15. The bottom of the flue formed by the light furnace wall is provided with a steel ash hopper and an air outlet, and the air outlet is connected to the bag-type dust collector 16 through an air pipe.

[0046] The bag-type dust collector 16 is connected with the inlet of the membrane wall chain plate flue 4 through the pipeline of the first circulating fan 19; the outlet of the membrane wall chain plate flue 4 is connected with the air chamber 10 through the second circulating fan 20. The cooled air in the bag-type dust collector 16 enters from the tail of the membrane wall chain plate flue 4 under the action of the first circulating fan 19, flows backward through the membrane wall chain plate flue, flows out from the head of the membrane wall chain plate flue 4, and then enters the air chamber 10 again under the action of the second circulating fan 20 for recycling, and the second circulating fan is a high-temperature fan.

[0047] The desalted water or soft water tank is connected to the water-cooled heat exchanger 15, the water-cooled screw conveyor 8 and the deaerator 18 in sequence; the desalted water or soft water tank is connected to the second water-cooled crusher 7, the first water-cooled crusher 6, the slag cooler 9 and the deaerator 18 in sequence.

[0048] The deaerator 18 is connected to the inlet of the economizer 14, the outlet of the economizer 14 is connected to the steam drum 17, the steam drum 17 is respectively connected to the water-cooled membrane wall of the membrane wall chain plate flue 4 and the water-cooled wall tube of the convection tube bundle 13, and then connected to the steam drum 17.

[0049] Example 2

[0050] The continuous slag slow cooling waste heat recovery system described in Example 1 is used to perform a continuous slag slow cooling waste heat recovery method, comprising the following steps:

[0051] (1) The high-temperature melt is discharged from the slag outlet of the pyrometallurgical furnace into the rotating intermediate slag ladle 1, and then enters the slag receiving pan 303 through the slag chute 2. The slag receiving pan 303 rotates with the rotating chain 305. When it rotates to the top of the second driving sprocket 306, the slag pan ejector 304 contacts the demoulding roller 307. Under the dual action of the demoulding roller 307 and the second driving sprocket 306, the slag pan ejector 304 is lifted up; when the slag receiving pan 303 rotates to the bottom of the second driving sprocket 306, under the dual action of the slag pan ejector 304 and the self-weight of the solidified slag, the solidified slag is automatically demoulded after the slag receiving pan 303 is turned over.

[0052] (2) The slag in the slag pot 5 exchanges heat with the tube-plate water-cooled wall of the slag pot 5. A first water-cooled crusher 6 is arranged below the slag pot 5, and the shaft and the moving and static plates of the first water-cooled crusher 6 are of water-cooled plate structure to ensure the crushing performance. A second water-cooled crusher 7 is arranged below the first water-cooled crusher 6, and the shaft and the counter-roller of the second water-cooled crusher 7 are of water-cooled tube and plate structure to ensure the crushing performance. The solidified slag that falls off is placed in the slag pot 5, and the slag in the slag pot 5 is crushed into coarse particles with a particle size of not more than 100 mm in the first water-cooled crusher 6 and then enters the second water-cooled crusher 7 to be crushed into fine particles with a particle size of not more than 10 mm. The fine slag particles enter a water-cooled screw conveyor 8 under the action of gravity, and the water-cooled screw conveyor 8 is of shell water-cooled structure. The high-temperature fine slag particles are conveyed to the fluidized hearth 11 through the water-cooled screw conveyor 8. At the same time, the nitrogen circulating air from the membrane wall chain plate flue 4 head enters the fluidized hearth 11 through the air chamber 10 under the action of the second circulating air fan 20. Under the action of the circulating air with a certain flow rate and flow velocity, the slag particles in the fluidized hearth 11 present a fluidized state, the thickness of the slag particle layer in the fluidized hearth 11 is controlled to form a fluidized bed, the slag particles in the fluidized hearth 11 present a suspended state, the heat exchange area and the heat exchange intensity with the nitrogen circulating air increase, the slag particles are cooled, and the nitrogen circulating air is heated. Under the action of the nitrogen fluidized circulating air, part of the slag particles are carried to the cyclone separator 12. In the cyclone separator 12, larger slag particles fall into the bottom under the action of cyclone separation and enter the fluidized hearth 11 through the connecting pipe connected to the lower part of the fluidized hearth 11 to be cooled in circulation. A connecting air pipe is arranged between the outlet of the second circulating air fan 20 and the air chamber 10 to the bottom of the cyclone separator 12, so that the large particles at the bottom of the cyclone separator can return to the fluidized hearth 11 smoothly. The thickness of the slag layer in the fluidized hearth is controlled within the target range through the slag discharging pipe arranged at the bottom of the fluidized hearth 11, and the slag particles in the slag layer of the fluidized hearth are discharged into the slag cooler 9 through the slag discharging pipe. The slag particles are further cooled to about 65℃ in the slag cooler and then discharged into the slag yard for storage as raw material of the slag preparation plant.

[0053] (3) The nitrogen circulating air, under the action of the cyclone separator 12, rotates and settles the large particle slag particles to the bottom, and a small amount of fine particle slag particles and nitrogen circulating air enter the flue formed by the light furnace wall from the top of the cyclone separator 12, and then pass through the convection tube bundle 13, the coal economizer 14, and the water-cooled heat exchanger 15 in sequence in the flue, and the temperature of the nitrogen circulating air is reduced to about 65°C, and then enters the bag dust collector 16 for purification and dust removal. The nitrogen circulating air has a certain amount of heat loss after passing through the bag dust collector 16 and the corresponding pipeline, and is introduced into the tail part of the membrane wall chain plate flue 4 under the action of the first circulating fan 19 at about 60°C. Because nitrogen is used as the circulating air, it will not condense at a low temperature of 60°C, and the normal operation of the bag dust collector 16 can be ensured. Steel hoppers are arranged at the bottom of the light furnace wall flue and the bottom of the bag dust collector 16 to collect the smoke dust particles carried by the circulating air. These smoke dust particles are fine particles formed in the solidification and crushing process of the molten slag, which are discharged to the slag yard through the ash discharge valve under the steel hopper for storage as raw materials of the slag preparation plant.

[0054] For the continuous slag slow cooling waste heat recovery system and device, because the circulating air is used, the heat loss of exhaust smoke can be avoided, the temperature of the discharged ash and slag is reduced to 65°C, the heat loss of the ash and slag is greatly reduced, and the overall thermal efficiency of the system is greatly improved compared with the traditional waste heat boiler.

[0055] (4) The nitrogen circulating air, after entering the tail of the membrane wall chain plate flue 4, expands rapidly in volume, the flow rate decreases, and flows out of the head of the membrane wall chain plate flue 4. Inside the membrane wall chain plate flue 4, the slag receiving tray 303 containing high-temperature melt moves in the opposite direction of the nitrogen circulating air. The molten slag in the slag receiving tray 303 is slowly cooled under the action of the nitrogen circulating air. The nitrogen circulating air is heated and its temperature is increased in the process of cooling the rotating chain 305 and the slag receiving tray 303. In actual operation, the maximum size of the slag receiving tray is controlled to be between 600-1000 mm. Because the size of the slag receiving tray 303 is much smaller than that of the traditional slag ladle, the time difference between the surface and the surrounding of the high-temperature molten slag in the slag receiving tray 303 cooling to solidification and the center cooling to solidification is greatly shortened, which can ensure that the molten slag in the slag receiving tray is slowly cooled to complete solidification within 8-10 hours, which is consistent with the cooling and solidification time of the surface and the surrounding of the traditional slag ladle. This cooling time can not only promote the growth of valuable metal grains, but also greatly shorten the time of the center cooling to solidification of the traditional slag ladle, without affecting the growth of metal grains, and also without affecting the normal operation of slag dressing. The running time of the slag receiving tray 303 is controlled to be about 10 hours, which can ensure that it is completely solidified before reaching the second driving sprocket 306. At this time, the temperature of the solidified molten slag in the slag receiving tray 303 is about 800-860℃, and the normal growth of valuable metal grains is not affected in this process. At the same time, the temperature of the nitrogen circulating air flowing out of the head of the membrane wall chain plate flue 4 is about 350℃. The membrane wall chain plate flue 4 absorbs heat through the radiation heat transfer of the slag receiving tray 303 and the molten slag and the convection heat transfer of the circulating nitrogen, heats the water in the membrane water cooling wall pipe into a steam-water mixture, and the steam-water mixture enters the steam drum 17 through the riser pipe.

[0056] (5) The continuous molten slag slow cooling waste heat recovery system also has a desalted water or soft water tank as the feed water of the whole system. The normal temperature water in the desalted water or soft water tank is pumped out in two ways under the action of the first water pump 21. The first way first enters the water inlet of the water cooling heat exchanger 15, enters the water outlet of the water cooling heat exchanger 15, enters the water inlet of the water cooling screw conveyor 8, and then enters the deaerator 18 through the water outlet of the water cooling screw conveyor 8. The second way first enters the water inlet of the second water cooling crusher 7, enters the water outlet of the second water cooling crusher 7, enters the water inlet of the first water cooling crusher 6, enters the water outlet of the first water cooling crusher 6, enters the water inlet of the slag cooler 9, and then enters the deaerator 18 through the water outlet of the slag cooler 9. The first way of water can reduce the temperature of the nitrogen circulating air to 65℃ through the counter-flow arranged water cooling heat exchanger 15, and then flows into the water cooling screw conveyor 8 to prevent the screw conveyor from being overheated and damaged. The second way of water, after being used as the cooling water of the first water cooling crusher 6 and the second water cooling crusher 7, enters the slag cooler 9 to further cool the slag particles discharged from the fluidized hearth 11. The two ways of water are very important for improving the thermal efficiency and stability of the continuous molten slag waste heat recovery system.

[0057] (6) The hot water in the deaerator 18 is pumped to the water-cooled wall pipe inlet of the economizer 14 by the second water pump 22, is further heated in the countercurrently arranged economizer, and then enters the steam drum 17 through the water-cooled wall pipe outlet of the economizer 14. The hot water in the steam drum 17 enters the water-cooled membrane wall of the membrane wall chain plate flue 4, the air chamber 10, the fluidized hearth 11, and the water-cooled wall pipe of the convection tube bundle 13 through the downcomer, respectively, is heated by the high-temperature nitrogen circulating air in these heating surfaces, and then returns to the steam drum 17 through the riser. After steam-water separation in the steam drum 17, steam is generated, which can be used for power generation or heat supply. In the process, the high-temperature circulating nitrogen gas is cooled for recycling.

[0058] The existing tunnel kiln or hot air room heat exchange technology is being developed and researched, and the waste heat recovery rate is generally lower than 30%. The high-temperature molten slag is slowly cooled to 60℃ by the present application, and the molten slag slow cooling waste heat recovery efficiency can reach 85% by the boiler steam. The system thermal efficiency is improved, no heavy metal sewage is produced, and no artificial mechanical coarse crushing is needed, which greatly reduces the risk of manual operation.

[0059] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and are not intended to limit the scope of protection of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A continuous slag slow cooling waste heat recovery system, characterized by, The automatic demolding chain plate system, the membrane wall chain plate flue, the water-cooled crusher, the water-cooled screw conveyor, the slag cooler, the air chamber, the fluidized hearth, the cyclone separator, the convection tube bundle, the coal economizer, the water-cooled heat exchanger, the bag-type dust collector, the desalted water tank or the soft water tank; The automatic demolding chain plate system is located in the membrane wall chain plate flue; the membrane wall chain plate flue is connected with the water-cooled crusher; the water-cooled crusher is connected with the first inlet below the fluidized hearth through the water-cooled screw conveyor; the outlet of the upper part of the fluidized hearth is connected with the inlet of the upper part of the cyclone separator, and the outlet of the bottom of the cyclone separator is connected with the second inlet below the fluidized hearth; the bottom of the fluidized hearth is connected with the air chamber and the slag cooler; the outlet of the top of the cyclone separator is sequentially connected with the convection tube bundle, the coal economizer, the water-cooled heat exchanger and the bag-type dust collector; the bag-type dust collector is connected with the inlet of the membrane wall chain plate flue; and the outlet of the membrane wall chain plate flue is connected with the air chamber. The desalted water tank or the soft water tank is sequentially connected with the water-cooled wall pipe water inlet of the water-cooled heat exchanger, the water-cooled wall pipe water inlet of the water-cooled screw conveyor and the deaerator; the desalted water tank or the soft water tank is sequentially connected with the water-cooled wall pipe water inlet of the water-cooled crusher, the water-cooled wall pipe water inlet of the slag cooler and the deaerator. The deaerator is connected with the water inlet of the coal economizer, and the water outlet of the coal economizer is connected with the steam drum; the water in the steam drum enters the membrane wall chain plate flue, the air chamber, the membrane water-cooled wall of the fluidized hearth and the water-cooled wall pipe of the convection tube bundle through the downcomer, and then the water in the membrane wall chain plate flue, the air chamber, the membrane water-cooled wall of the fluidized hearth and the water-cooled wall pipe of the convection tube bundle returns to the steam drum through the upcomer. The automatic demolding chain plate system comprises a first driving sprocket, a slag receiving disc, a slag disc thimble, a rotating chain, a second driving sprocket and a demolding ring; the rotating chain is driven to rotate by the first driving sprocket and the second driving sprocket arranged at the head and tail ends respectively; the second driving sprocket is provided with the demolding ring coaxial with the second driving sprocket; the slag receiving disc is connected with the rotating chain; a hole is formed in the middle of the bottom of the slag receiving disc; the slag disc thimble is precisely matched with the hole in the bottom of the slag receiving disc; the slag disc thimble is freely movable in the hole; and the bottom of the slag receiving disc is sealed after the slag disc thimble and the slag receiving disc are closed. The membrane wall chain plate flue is formed by the upper and lower and left and right and front and back six surfaces of the membrane water-cooled wall structure; the slag hopper is connected with the membrane wall chain plate flue and located below the second driving sprocket; the slag hopper is formed in the shape of a funnel by the pipe plate type water-cooled wall. The continuous molten slag slow cooling waste heat recovery system further comprises a rotating intermediate slag ladle and a slag chute; the rotating intermediate slag ladle is arranged between the metallurgical furnace kiln slag discharge port and the slag chute; one end of the slag chute is located below the rotating intermediate slag ladle, and the other end is located above the automatic demolding chain plate system; the bottom of the rotating intermediate slag ladle is provided with an electric rotating motor; the first driving sprocket and the second driving sprocket of the automatic demolding chain plate system are respectively connected with driving motors; and the electric rotating motor and the driving motors are all servo motors.

2. The continuous slag slow cooling waste heat recovery system according to claim 1, wherein, The water-cooled crusher comprises a first water-cooled crusher and a second water-cooled crusher; and the membrane wall chain plate flue is sequentially connected with the slag hopper, the first water-cooled crusher and the second water-cooled crusher.

3. The continuous slag slow cooling waste heat recovery system according to claim 1, wherein The membrane wall chain plate flue is internally provided with four sets of parallel automatic demolding chain plate systems, and the four sets of parallel automatic demolding chain plate systems are synchronously meshed, rotated and moved through four sprockets which are provided with the same shape and size as the first driving sprocket and the second driving sprocket.

4. The continuous slag slow cooling waste heat recovery system according to claim 1, wherein The cloth bag dust collector is connected with the membrane wall chain plate flue inlet through a pipeline provided with the first circulating fan; and the membrane wall chain plate flue outlet is connected with the air chamber through the second circulating fan.

5. The continuous slag slow cooling waste heat recovery system according to claim 4, wherein A connecting air pipe is arranged between the outlet of the second circulating fan and the air chamber and connected to the bottom of the cyclone separator.

6. The continuous slag slow cooling waste heat recovery system according to claim 2, wherein The desalted water or soft water tank is connected with the water inlet of the water-cooled heat exchanger and the water inlet of the second water-cooled crusher through the first water pump; and the deaerator is connected with the water inlet of the economizer through the second water pump.

7. A method for continuously recovering the waste heat of a smelted slag by using the continuously smelted slag slow cooling waste heat recovery system according to claim 2, characterized in that, The method comprises the following steps: (1) The high-temperature melt discharged from the slagging port of the pyrometallurgical furnace is introduced into a rotating intermediate slag ladle, and then introduced into a slag receiving disc through a slag chute, the slag receiving disc rotates with the rotating chain, and when the slag receiving disc rotates to the position directly above the second driving sprocket, the slag receiving disc needle contacts the demolding rolling ring, and the slag receiving disc needle is lifted; when the slag receiving disc rotates to the position directly below the second driving sprocket, the slag receiving disc is turned over, and the solidified slag is automatically demolded; (2) The solidified slag after demolding is placed in a slag hopper, and then crushed into slag particles by the first water-cooled crusher and the second water-cooled crusher, the slag particles are conveyed into the fluidized furnace chamber by the water-cooled screw conveyor, the nitrogen circulating air from the head of the membrane wall chain plate flue enters the fluidized furnace chamber through the air chamber, the slag particles in the fluidized furnace chamber are in a fluidized state, and heat exchange is performed between the slag particles and the nitrogen circulating air, the slag particles are cooled, and the nitrogen circulating air is heated; the nitrogen circulating air carrying part of the slag particles enters the cyclone separator, and the large-particle slag particles are rotated and settled to the bottom, the fine-particle slag particles and the nitrogen circulating air sequentially pass through the convection tube bundle, the economizer and the water-cooled heat exchanger from the top of the cyclone separator, the temperature of the nitrogen circulating air is lowered, and then the nitrogen circulating air enters the cloth bag dust collector for purification and dust removal; (3) The nitrogen circulating air after dust removal by the cloth bag dust collector enters the tail of the membrane wall chain plate flue, and moves reversely with the slag receiving disc containing the high-temperature melt, the high-temperature slag in the slag receiving disc is cooled into solid slag, and the nitrogen circulating air flows out of the head of the membrane wall chain plate flue into the air chamber; at the same time, the water in the membrane wall of the membrane wall chain plate flue is heated into a steam-water mixture and enters the steam drum; (4) The water in the desalted water or soft water tank is output in two ways, the first way of water first enters the water inlet of the water-cooled heat exchanger, enters the water inlet of the water-cooled screw conveyor through the outlet of the water-cooled heat exchanger, and enters the deaerator through the water outlet of the water-cooled screw conveyor; the second way of water first enters the water inlet of the second water-cooled crusher, enters the water inlet of the first water-cooled crusher through the outlet of the second water-cooled crusher, enters the water inlet of the slag cooler through the outlet of the first water-cooled crusher, and enters the deaerator through the outlet of the slag cooler. (5) The water in the deaerator is transported to the water inlet of the economizer, and then enters the steam drum through the water outlet of the economizer, and the water in the steam drum enters the membrane wall chain flue, the air chamber, the membrane water cooling wall pipe of the fluidized hearth and the water cooling wall pipe of the convection pipe bundle respectively, and the water in the membrane wall chain flue, the air chamber, the membrane water cooling wall pipe of the fluidized hearth and the water cooling wall pipe of the convection pipe bundle is heated by high-temperature nitrogen circulating air and returned to the steam drum, and steam is generated after steam-water separation in the steam drum, and the steam is used for power generation or heat supply.

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