Blast furnace slag flushing water heat energy comprehensive utilization system

Abstract

The utility model discloses a blast furnace slag flushing water heat energy comprehensive utilization system which comprises a slag flushing pool and evaporators, the evaporators comprise an upper evaporator and a lower evaporator, a cylinder is transversely arranged in the upper evaporator, a plurality of filter holes are evenly formed in the cylinder, a rotating shaft is concentrically arranged in the cylinder, and spiral blades are arranged on the rotating shaft. A slag box is arranged on the outer side of the upper evaporator, the discharging end of the cylinder extends into the slag box, a water inlet pipe is obliquely arranged on the side wall of the upper evaporator, the end of the water inlet pipe is communicated with the top of the feeding end of the cylinder, the two evaporators are communicated with vacuum pumps, exhaust pipes are arranged on the tops of the two evaporators, and the ends of the exhaust pipes are connected with a generator set. A condensate water outlet of the generator set is connected with a heat exchanger, a condensate water outlet of the heat exchanger is communicated with a slag flushing pool, and a water outlet of the slag flushing pool is communicated with a water inlet pipe. In conclusion, the waste heat recovery device has the advantages of being capable of fully recovering waste heat, not prone to blockage and high in recovery efficiency.

Description

Technical Field

[0001] The utility model relates to the technical field of waste heat recovery and utilization, in particular to a blast furnace slag flushing water heat energy comprehensive utilization system. Background Art

[0002] In the blast furnace ironmaking process, a large amount of slag with a temperature of about 1000℃ is produced, which contains about 30% of the heat in the blast furnace molten iron. The slag treatment method of most ironmaking companies is: the slag is quickly cooled into water slag and granulated in the slag box by a high-speed water flow provided by the slag pump for cement production. A large amount of hot water with a temperature of 80-95℃ is generated in this process. Usually, in order to ensure the recycling effect of the slag water, this part of the slag water needs to be introduced into an air cooling tower after sedimentation and filtration, and the temperature is reduced to below 50℃ and recycled for slag flushing. This will cause a large part of the heat in the slag to be lost in the air cooling tower, which not only causes energy waste, but also causes thermal pollution to the environment. Therefore, recovering the waste heat of blast furnace slag water can save energy and protect the environment, which is of great significance.

[0003] Heating mainly utilizes the waste heat from blast furnace slag flushing water, which has the advantages of simple technology and low transformation cost. However, it also has the following problems: First, the slag flushing water has a large volume and contains a large amount of heat, so the waste heat in the slag flushing water is often not fully utilized; second, the slag flushing water contains a large amount of impurities and the water quality is poor, which not only affects the recovery of waste heat, but also easily causes blockage of pipelines and equipment, affecting the recovery efficiency of the waste heat of the slag flushing water. Therefore, it is an objective need to develop a blast furnace slag flushing water heat energy comprehensive utilization system that can fully recover waste heat, is not easy to clog, and has high recovery efficiency. Utility Model Content

[0004] The purpose of the utility model is to provide a blast furnace slag flushing water heat energy comprehensive utilization system which can fully recover waste heat, is not easy to be blocked and has high recovery efficiency.

[0005] The purpose of the present invention is achieved in this way, including a slag flushing pool and an evaporator, the evaporator includes an upper evaporator and a lower evaporator, a slag discharge pipe is provided at the bottom of each evaporator, a gate valve is provided on the slag discharge pipe, the slag discharge pipe of the upper evaporator is connected to the top of the lower evaporator, a cylinder is horizontally arranged in the upper evaporator, a number of filter holes are evenly processed on the cylinder, a rotating shaft is concentrically arranged in the cylinder, spiral blades are provided on the rotating shaft, one end of the rotating shaft extends out of the upper evaporator and is connected to a motor for transmission, a slag box is provided on the outside of the upper evaporator, the discharge end of the cylinder extends into the slag box, a water inlet pipe is obliquely provided on the side wall of the upper evaporator, the end of the water inlet pipe is connected to the top of the cylinder feeding end, both evaporators are connected to a vacuum pump, both evaporators are provided with an exhaust pipe, the end of the exhaust pipe is connected to a generator set, the condensate outlet of the generator set is connected to a heat exchanger, the condensate drain outlet of the heat exchanger is connected to the slag flushing pool, and the drain outlet of the slag flushing pool is connected to the water inlet pipe.

[0006] Furthermore, a splash mechanism is provided in the upper evaporator below the cylinder, which includes an inclined shaft and a disc arranged at intervals on the inclined shaft, with water guide strips evenly distributed on the circumference of the disc. A driving mechanism for driving the inclined shaft to rotate is installed on the outside of the upper evaporator.

[0007] Furthermore, an arc-shaped water baffle is provided in the upper evaporator between the splash mechanism and the cylinder, and a plurality of protrusions are provided on the lower surface of the water baffle.

[0008] Furthermore, demisters are provided at the tops of the upper evaporator and the lower evaporator.

[0009] Furthermore, the lower end of the slag discharge pipe of the lower evaporator is connected to a slag-water separator, and the water outlet of the slag-water separator is connected to the slag flushing pool through a pipeline.

[0010] Furthermore, a steam buffer tank is provided at the air inlet end of the generator set, and the exhaust pipes of the two evaporators are both connected to the steam buffer tank.

[0011] Furthermore, the pressure in the lower evaporator is lower than the pressure in the upper evaporator.

[0012] The utility model is used for the recovery and utilization of heat energy of blast furnace slag flushing water. During operation, the pressure in the two evaporators is first reduced by a vacuum pump, and the slag flushing water in the slag flushing pool enters the cylinder from the water inlet pipe. The motor is started, and the motor drives the rotating shaft and the spiral blades to rotate. The spiral blades push the slag flushing water forward during the rotation process. During the movement, the slag flushing water continuously leaks out from the filter holes on the cylinder, while the impurities in the slag flushing water are blocked and remain in the cylinder. The slag flushing water continues to move forward under the push of the spiral blades until it falls into the slag box from the discharge end of the cylinder. When the pressure is low, the boiling point of the slag water decreases and it continues to evaporate into water vapor. After a period of time, a certain amount of slag flushing water that has not evaporated will gather in the upper evaporator and be passed into the lower evaporator to continue evaporating into water vapor under low pressure. Water vapor is continuously generated in the two evaporators, and this water vapor is passed into the generator set to generate electricity. The discharged condensed water is passed into the heat exchanger, and the waste heat in the condensed water is used to heat domestic water to obtain hot water that can be used for heating. Finally, the discharged condensed water is returned to the slag flushing pool for continued use. In the above process, the principle of reducing pressure and thus lowering the boiling point of slag flushing water is adopted, so that the slag flushing water of about 80°C is quickly evaporated into water vapor, and a two-stage evaporation structure is adopted to evaporate the slag flushing water as much as possible, and then the water vapor is used to generate electricity, and the condensed water after power generation is used to heat the cold water to obtain hot water for heating. The whole process can be carried out continuously, and the waste heat in the slag flushing water can be fully utilized to reduce the heat loss in the slag flushing water. Secondly, the utility model adopts the structure of a screw conveyor to filter the impurities in the slag flushing water, and at the same time adopts the principle of reducing pressure and thus lowering the boiling point of the slag flushing water to separate the slag flushing water and impurities. The water vapor transmission pipeline is not easy to be blocked, and most of the impurities are sent to the slag box. A very small number of impurities with smaller particles are mixed in the slag flushing water, which is not easy to cause blockage of the pipeline and equipment, and the slag flushing water with separated impurities has a higher waste heat recovery efficiency. In summary, the utility model has the advantages that waste heat can be fully recovered, is not easy to be blocked, and has a high recovery efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0014] In the figure: 1-slag flushing pool, 2-upper evaporator, 3-lower evaporator, 4-slag discharge pipe, 5-cylinder, 6-filter hole, 7-spiral blade, 8-slag box, 9-water inlet pipe, 10-vacuum pump, 11-exhaust pipe, 12-generator set, 13-heat exchanger, 14-inclined axis, 15-disc, 16-drive mechanism, 17-water baffle, 18-demister, 19-slag-water separator, 20-steam buffer tank. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with the accompanying drawings, but the present invention is not limited in any way. Any changes or improvements based on the present invention fall within the scope of protection of the present invention.

[0016] like Figure 1 As shown, the utility model includes a slag flushing pool 1 and an evaporator. The evaporator includes an upper evaporator 2 and a lower evaporator 3. A slag discharge pipe 4 is provided at the bottom of each evaporator. A gate valve is provided on the slag discharge pipe 4. The slag discharge pipe 4 of the upper evaporator 2 is connected to the top of the lower evaporator 3. A cylinder 5 is horizontally provided in the upper evaporator 2. A plurality of filter holes 6 are evenly processed on the cylinder 5. A rotating shaft is concentrically provided in the cylinder 5. A spiral blade 7 is provided on the rotating shaft. One end of the rotating shaft extends out of the upper evaporator 2 and is connected to a motor for transmission. The motor is an existing device. Its power, speed and other parameters are determined according to actual needs. A slag box 8 is provided on the outside of the upper evaporator 2. The discharge end of the cylinder 5 extends into the slag box 8. The upper evaporator 2 A water inlet pipe 9 is obliquely provided on the side wall, and the end of the water inlet pipe 9 is connected to the top of the feeding end of the cylinder 5. A vacuum pump 10 is connected to both evaporators. An exhaust pipe 11 is provided on the top of both evaporators. The end of the exhaust pipe 11 is connected to a generator set 12. The generator set 12 is a prior art and can generate electricity using water vapor. The condensate outlet of the generator set 12 is connected to a heat exchanger 13. The heat exchanger 13 is an existing structure. In the utility model, the heat exchanger 13 is used to realize the heat exchange between condensate water and heating water, reduce the temperature of condensate water, and increase the temperature of water for exchange. The condensate drain outlet of the heat exchanger 13 is connected to the slag flushing pool 1, and the drain outlet of the slag flushing pool 1 is connected to the water inlet pipe 9.

[0017] The utility model is used for the recovery and utilization of heat energy of blast furnace slag flushing water. During operation, the pressure in the two evaporators is first reduced by the vacuum pump 10, and the slag flushing water in the slag flushing pool 1 enters the cylinder 5 from the water inlet pipe 9. The motor is started, and the motor drives the rotating shaft and the spiral blade 7 to rotate. The spiral blade 7 pushes the slag flushing water forward during the rotation process. During the movement, the slag flushing water continuously leaks out from the filter holes 6 on the cylinder 5, while the impurities in the slag flushing water are blocked and remain in the cylinder 5. The impurities continue to move forward under the push of the spiral blade 7 until they fall into the slag box 8 from the discharge end of the cylinder 5. In the slag flushing water, the boiling point is lowered under low pressure and it continues to evaporate into water vapor. After a period of time, a certain amount of slag flushing water that has not evaporated will gather in the upper evaporator 2, and it will be passed into the lower evaporator 3 to continue evaporating into water vapor under low pressure. Water vapor is continuously generated in the two evaporators, and this water vapor is passed into the generator set 12 to generate electricity. The discharged condensed water is passed into the heat exchanger 13, and the waste heat in the condensed water is used to heat domestic water to obtain hot water that can be used for heating. Finally, the discharged condensed water is returned to the slag flushing pool 1 for continued use.

[0018] In the above process, the principle of reducing pressure and thus lowering the boiling point of slag flushing water is adopted, so that the slag flushing water at about 80°C evaporates quickly into water vapor, and a two-stage evaporation structure is adopted to evaporate the slag flushing water as much as possible, and then use the water vapor to generate electricity, and then use the condensed water after power generation to heat the cold water to obtain hot water for heating. The whole process can be carried out continuously, and the waste heat in the slag flushing water can be fully utilized to reduce the heat loss in the slag flushing water; secondly, the utility model adopts the structure of a screw conveyor to filter impurities in the slag flushing water, and at the same time adopts the principle of reducing pressure and thus lowering the boiling point of slag flushing water to separate the slag flushing water and impurities. The water vapor transmission pipeline is not easy to be blocked, and most of the impurities are sent to the slag box 8. A very small number of impurities with smaller particles are mixed in the slag flushing water, which is not easy to cause blockage of pipes and equipment, and the slag flushing water with separated impurities has a higher waste heat recovery efficiency. In addition, in the present invention, the upper evaporator 2 and the lower evaporator 3 are arranged in an upper and lower structure. The slag flushing water in the upper evaporator 2 can fall into the lower evaporator 3 under the action of its own gravity without consuming additional energy. Compared with some current methods that require special pipes and water pumps to pump, it can save manufacturing costs and energy consumption.

[0019] A splash mechanism is installed within the upper evaporator 2 below the cylinder 5. The splash mechanism comprises an inclined shaft 14 and a disc 15 spaced apart on the inclined shaft 14. Water guide strips are evenly distributed around the circumference of the disc 15. A drive mechanism 16 is mounted on the exterior of the upper evaporator 2 to drive the inclined shaft 14. This drive mechanism 16 utilizes existing technology and can rotate the inclined shaft 14, which in turn drives the disc 15, which in turn drives the water guide strips. As the water guide strips rotate, they continuously draw up and discard the slag-flushing water, thereby forming more and smaller water droplets, promoting the vaporization of the slag-flushing water and accelerating its vaporization efficiency.

[0020] An arc-shaped water baffle 17 is provided in the upper evaporator 2 between the splash mechanism and the cylinder 5, and a plurality of protrusions are provided on the lower surface of the water baffle 17. In actual operation, it is found that the splash mechanism throws out the water in the upper evaporator 2. Due to the effect of inertia, the water droplets will fly a certain distance, and some water droplets will fly upwards and then hit the cylinder 5. On the one hand, this will affect the leakage of water in the cylinder 5. On the other hand, the impact of water droplets on the cylinder 5 will also cause vibration of the cylinder 5 and its internal parts, which is not conducive to the normal operation of the equipment. For this reason, the water baffle 17 is provided, which has two functions: first, it blocks water droplets so that they cannot hit the cylinder 5; second, when water droplets hit the water baffle 17, especially when they hit the protrusions, more and smaller water droplets will be produced, which is more conducive to the vaporization of slag flushing water, increases the vaporization speed of slag flushing water, and vaporizes as much slag flushing water as possible.

[0021] A demister 18 is provided on the top of the upper evaporator 2 and the lower evaporator 3. The demister 18 is an existing mechanism. During the operation of the utility model, the slag flushing water flashes in the upper evaporator 2 and the lower evaporator 3 to form water vapor. These water vapors contain a certain amount of moisture and impurities. Through the setting of the demister 18, these moisture and impurities are removed, the water content of the water vapor is reduced, the impurity content in the water vapor is reduced, the water vapor is purified, and the water vapor is prevented from entering the generator set 12 and affecting the normal operation of the generator set 12.

[0022] The lower end of the slag discharge pipe 4 of the lower evaporator 3 is connected to a slag-water separator 19, and the water outlet of the slag-water separator 19 is connected to the slag flushing pool 1 through a pipeline. During actual operation, there will always be some fine impurities mixed in the slag flushing water, which cannot be blocked by the filter holes 6 on the cylinder 5. These fine impurities first fall into the upper evaporator 2 and then fall into the lower evaporator 3. After the slag-water separator 19 is set, these impurities will enter the slag-water separator 19 along with part of the slag flushing water. The slag-water separator 19 is an existing technology, which is used to separate fine impurities and slag flushing water, improve the water quality of the slag flushing water, and then return the purified slag flushing water to the slag flushing pool 1 for continued recycling, saving water resources.

[0023] A steam buffer tank 20 is provided at the air inlet end of the generator set 12, and the exhaust pipes 11 of the two evaporators are connected to the steam buffer tank 20. Two evaporators are provided in the utility model, and the slag flushing water will enter the upper evaporator 2 and the lower evaporator 3 in turn. The order of flash evaporation also determines that the temperature of the steam obtained is different. Generally speaking, the steam temperature obtained in the upper evaporator 2 is about 70°C or above, and the steam temperature obtained in the lower evaporator 3 is about 60°C. It can be seen that there is a difference between the two steam temperatures. Directly passing them into the generator set 12 may cause unstable operation of the generator set 12 due to the difference in steam temperature and the fluctuation of steam supply. In order to solve this problem, a steam buffer tank 20 is provided, in which the two steams are mixed, the temperature is averaged, and the pressure output is stabilized, thereby outputting relatively constant temperature and pressure steam, so that the generator set 12 can operate normally and stably.

[0024] The pressure in the lower evaporator 3 is lower than the pressure in the upper evaporator 2. In the present invention, the slag flushing water will enter the upper evaporator 2 and the lower evaporator 3 successively, among which the upper evaporator 2 is the main evaporator, and most of the slag flushing water is vaporized in the upper evaporator 2, while the lower evaporator 3 is the auxiliary evaporator, which is used to vaporize the slag flushing water that does not have time to vaporize in the upper evaporator 2. In order to improve the vaporization efficiency of the slag flushing water, the slag flushing water is vaporized into water vapor as much as possible to reduce the pressure in the lower evaporator 3. Generally speaking, the air pressure of the upper evaporator 2 can be controlled at about 30KPa, and the air pressure of the lower evaporator 3 can be controlled at about 20KPa, to ensure that the slag flushing water can flash evaporate quickly after entering the upper evaporator 2 and the lower evaporator 3.

Claims

1. A blast furnace slag flushing water heat energy comprehensive utilization system, comprising a slag flushing pool (1) and an evaporator, characterized in that The evaporator comprises an upper evaporator (2) and a lower evaporator (3), a slag discharge pipe (4) is provided at the bottom of each evaporator, a gate valve is provided on the slag discharge pipe (4), the slag discharge pipe (4) of the upper evaporator (2) is connected to the top of the lower evaporator (3), a cylinder (5) is transversely provided in the upper evaporator (2), a plurality of filter holes (6) are uniformly processed on the cylinder (5), a rotating shaft is concentrically provided in the cylinder (5), a spiral blade (7) is provided on the rotating shaft, one end of the rotating shaft extends out of the upper evaporator (2) and is connected to a motor for transmission, and a slag box (8) is provided on the outer side of the upper evaporator (2) The discharge end of the cylinder (5) extends into the slag box (8), a water inlet pipe (9) is obliquely provided on the side wall of the upper evaporator (2), the end of the water inlet pipe (9) is connected to the top of the feed end of the cylinder (5), both evaporators are connected to a vacuum pump (10), both evaporators are provided with an exhaust pipe (11), the end of the exhaust pipe (11) is connected to a generator set (12), the condensate outlet of the generator set (12) is connected to a heat exchanger (13), the condensate drain port of the heat exchanger (13) is connected to the slag flushing pool (1), and the drain port of the slag flushing pool (1) is connected to the water inlet pipe (9).

2. A blast furnace slag washing water heat energy comprehensive utilization system according to claim 1, characterized in that A splash mechanism is provided in the upper evaporator (2) below the cylinder (5), and the splash mechanism comprises an inclined shaft (14) and a disk (15) spaced apart on the inclined shaft (14), and water guide strips are evenly distributed on the circumference of the disk (15). A driving mechanism (16) for driving the inclined shaft (14) to rotate is installed outside the upper evaporator (2).

3. A blast furnace slag washing water heat energy comprehensive utilization system according to claim 2, characterized in that An arc-shaped water baffle (17) is provided in the upper evaporator (2) between the splash mechanism and the cylinder (5), and a plurality of protrusions are provided on the lower surface of the water baffle (17).

4. A blast furnace slag washing water heat energy comprehensive utilization system according to claim 1, characterized in that : A defoamer (18) is provided at the top of each of the upper evaporator (2) and the lower evaporator (3).

5. A blast furnace slag washing water heat energy comprehensive utilization system according to claim 1, characterized in that The lower end of the slag discharge pipe (4) of the lower evaporator (3) is connected to a slag-water separator (19), and the water outlet of the slag-water separator (19) is connected to the slag flushing pool (1) through a pipeline.

6. A blast furnace slag washing water heat energy comprehensive utilization system according to claim 1, characterized in that The air inlet end of the generator set (12) is provided with a steam buffer tank (20), and the exhaust pipes (11) of the two evaporators are both connected to the steam buffer tank (20).

7. A blast furnace slag washing water heat energy comprehensive utilization system according to claim 1, characterized in that The pressure in the lower evaporator (3) is lower than the pressure in the upper evaporator (2).

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