CN112708710A

CN112708710A - Waste heat recovery system for steel smelting

Info

Publication number: CN112708710A
Application number: CN202011503918.XA
Authority: CN
Inventors: 杨帆; 易启堂
Original assignee: Chongqing Yanyu Energy Saving Technology Co ltd
Current assignee: Chongqing Yanyu Energy Saving Technology Co ltd
Priority date: 2020-12-18
Filing date: 2020-12-18
Publication date: 2021-04-27

Abstract

The invention relates to the technical field of waste heat recovery equipment, and particularly discloses a waste heat recovery system for steel smelting, which is arranged close to a smelting furnace with a discharge hole at the bottom. This patent abandons the mode that utilizes the dolly to transport among the prior art, has improved the waste heat recovery of slag and broken efficiency.

Description

Waste heat recovery system for steel smelting

Technical Field

The invention relates to the technical field of waste heat recovery equipment, in particular to a waste heat recovery system for steel smelting.

Background

In a metallurgical process, a large amount of waste slag (for example, coal slag, iron slag, etc.) is generally generated, and the waste slag is molten at a high temperature, and is generally cooled, crystallized and crushed for convenience of collection, storage and secondary utilization. The traditional high-temperature slag cooling method comprises natural cooling, air cooling, water cooling and the like, but the method has the following problems: (1) the temperature of the high-temperature furnace slag is high (the temperature of the steel furnace slag is 1000-1600 ℃), so that the required cooling time is long; (2) a large amount of waste heat is contained in the high-temperature furnace slag, and the waste heat cannot be utilized in the mode, so that energy is wasted.

Based on such problem, I have carried out a series of technical research and development, developed one set and be applicable to high temperature lava, molten slurry, solution class waste heat recovery system, heat absorption head in this system, including the cavity roller that the level set up, scraper blade and disconnected sediment sword, roller half submergence is in the slag jar that is equipped with the melting slay, through the drive roller rotation, cooling medium (liquid metal) is in the inside continuous circulation flow of roller, under the cooperation of scraper blade and disconnected sediment sword, realized the waste heat recovery of mineral liquid, the slay that will solidify simultaneously is broken into piece or graininess.

Above-mentioned system has made the higher evaluation of enterprise in the waste heat recovery industrial application of slag, scum, but because in some steel smelting fields, the smelting furnace that often adopts is for empting the stove, therefore the slag need be transported to slag jar department through the dolly, and the mode has increased slag waste heat recovery's process like this, be unfavorable for the promotion of efficiency, especially to arrange the smelting furnace of row material and row sediment through bottom discharge gate, the waste heat recovery system of the smelting furnace that arranges material and arrange the sediment to carrying out from bottom discharge gate specially has been researched and developed based on this department to improve the waste heat recovery and the broken handle efficiency of slag.

Disclosure of Invention

The invention provides a waste heat recovery system for iron and steel smelting, which aims to solve the problems that in the prior art, high-temperature furnace slag is transported by a trolley, the process of recovering waste heat of the furnace slag is increased, and the efficiency is not improved.

In order to achieve the purpose, the technical scheme of the invention is as follows:

the waste heat recovery system for steel smelting is arranged close to a smelting furnace with a discharge hole at the bottom and comprises a frame, a heat absorption assembly, a slag cylinder, a granulator, a lifting conveyor, a secondary heat exchange system and a belt conveyor, the heat absorption component comprises a heat absorption head, the heat absorption head comprises a hollow roller and two hollow shafts, the two hollow shafts are respectively and coaxially fixed at two ends of the roller, the two hollow shafts are rotationally connected on the frame, the slag cylinder is arranged below the roller, a diversion trench is arranged on the frame, one end of the diversion trench is positioned below the discharge port, the other end of the diversion trench is positioned above the slag cylinder, one side of the diversion trench close to the slag cylinder is hinged on the frame, the granulator is characterized in that a driving piece for driving the diversion trench to swing around a hinge point is arranged on the rack, a plurality of barrier strips are arranged on the roller and are evenly distributed along the circumferential direction of the outer wall of the roller, a slag receiving hopper is further arranged at the top of the granulator, and the slag receiving hopper is close to the roller of the heat absorption head respectively.

The technical principle and the effect of the technical scheme are as follows:

1. in this scheme, accomplish a stove after the smelting furnace and smelt, earlier make the guiding gutter leave the discharge gate bottom of smelting furnace through the driving piece, treat the steel and iron solution discharge back, the rethread driving piece makes the guiding gutter swing to the bottom of discharge gate, the slag in the back melting furnace passes through the discharge gate and discharges, enter into the guiding gutter, and in getting into the slag jar along the guiding gutter, because the slag temperature that discharges from the smelting furnace this moment is up to 1000 ~ 1600 ℃, therefore this in-process, the molten slag is difficult to condense, can flow into in the slag jar fast, by waste heat recovery and broken handle, therefore this scheme has abandoned the mode of utilizing the dolly to transport among the prior art, the waste heat recovery and the broken efficiency of slag have been improved.

2. Get into the melting slag of slag pot in this scheme, carry out waste heat recovery through the heat absorption subassembly, specific principle is: molten slag gets into in the slag ladle and makes roller part submergence in the solution, hollow shaft and roller synchronous rotation in the heat absorption head, simultaneously cooling medium passes through external circulation system and constantly flows from a left side to the right side or from a right side to the left side in the heat absorption head, when the roller rotates, molten slag attaches on the surface of roller in the slag ladle, and constantly keep away from the slag ladle along with the rotation of roller, and solidify into strip slag layer under the effect of cooling medium heat transfer gradually, and even the slag has solidified the caking at this moment, because blockking of blend stop, the slag layer is difficult for peeling off and dropping once more in the slag ladle from the outer wall of roller, and when removing to being close to slag receiving fill one side, strip slag layer is under the effect of self gravity and roller centrifugal force, fall into in the slag receiving fill, thereby the waste heat recovery and the broken handle to molten slag have been accomplished.

3. Compare in prior art's heat absorption head in addition, fused slag can form one deck solidification layer at the roller outer wall among the prior art, consequently need scraper subassembly and disconnected slag subassembly's combined action, accomplish the breakage of solidification layer, and in this scheme, a plurality of blend stop settings except can stopping that the slag blanket falls into the slag ladle, a plurality of blend stops can also make fused slag just form a plurality of banding slag blankets when roller surface solidifies, and a non-monoblock solidification layer, the bar slag blanket just can be broken when falling into and connect the slag fill like this, make the structure of heat absorption head simpler, the problem that the bold layer peeled off and falls into the slag ladle has also been prevented simultaneously from taking place.

4. The slag fragments that get into in this scheme and connect the sediment fill are broken into even granule under the granulator effect to convey the secondary heat transfer system through promoting the conveyer in, further reduce the temperature of granule to room temperature or lower temperature, later under band conveyer's effect, in being transported to rubbing crusher or finished product storehouse according to specific need.

Furthermore, the guiding gutter is the slope setting, and the guiding gutter is close to discharge gate one end and is located the top that is close to slag cylinder one end.

Has the advantages that: this enables slag discharged from the smelting furnace to quickly pass through the launder into the slag pot.

Furthermore, the side wall of the slag receiving hopper far away from the roller is higher than the side wall of the slag receiving hopper near the roller, and a permanent magnet is fixed on the side wall of the slag receiving hopper far away from the roller.

Has the advantages that: set up like this and can prevent on the one hand that solidification slag from throwing away the sediment fill under centrifugal force effect, on the other hand because most steel slag have magnetism, consequently under the magnetic attraction effect of permanent magnet, it breaks away from the roller more easily and drops in the sediment fill.

Furthermore, the number of the heat absorption heads is three, the transverse cross section of the slag cylinder is in a convex shape, one heat absorption head is positioned at the convex part at the top of the slag cylinder, and the other two heat absorption heads are positioned at the convex parts at the two sides of the slag cylinder.

Has the advantages that: because the heat absorption head is equipped with threely in this scheme, and the form of arranging of three heat absorption head, can make and accomplish waste heat recovery and the broken handle of a large amount of melting slag simultaneously in the slag pot, such mode can reduce the problem that the slag is detained in the slag pot, thereby also reduce the piling up that the melting slag solidifies the formation, in addition when one of them heat absorption head need overhaul, two other heat absorption heads need not shut down, waste heat recovery and the broken handle of slag can not interrupt promptly, thereby made things convenient for the maintenance to whole heat absorption subassembly to overhaul.

Furthermore, the barrier strips are arc-shaped, planes of two ends of the barrier strips do not coincide with a plane of the middle of the barrier strips, and the orientation of the arc-shaped concave surface of each barrier strip is the same as the rotation direction of the roller.

Has the advantages that: because when the heat absorption head works, the temperature of the roller close to the input end of the cooling medium is lower than that of the output end of the cooling medium, so that the cooling speed of the molten slag attached to the input end is slightly higher than that of the molten slag attached to the other end, the molten slag has a higher solidification speed on the outer wall of the roller at the input end, the thickness of the solidified slag layer is larger than that of other parts at the same time, if the solidified thickness exceeds the height of the barrier strip, the barrier strip can have a limited blocking effect, and therefore, by adopting the scheme, the molten slag has a tendency of flowing towards the middle part of the barrier strip, and the tendency of solidifying the molten slag layer to be thicker at the end part of the roller is slowed down.

Furthermore, the barrier strips are provided with scraping seams, the scraping seams on the upper and lower adjacent barrier strips are located on the same circumferential line of the roller, a scraper is arranged on one side, close to the slag cylinder, of the slag receiving hopper, and the tops of the scrapers are close to the outer wall of the roller and can pass through the scraping seams.

Has the advantages that: the arrangement is that when the strip-shaped slag layer solidified on the roller rotates to one side close to the slag receiving hopper, the strip-shaped slag layer is cut off under the action of the scraper, so that the function of helping the strip-shaped slag layer to be broken is achieved.

Furthermore, the upper scraping seams of the barrier strips are provided with a plurality of scrapers, and the corresponding scrapers are also provided with a plurality of scrapers.

Has the advantages that: this causes the scraper to break the strip-shaped slag layer more finely.

Furthermore, an annular groove is formed in the outer wall of the roller along the circumferential direction of the roller, and the annular groove is communicated with the vertically adjacent scraping seams.

Has the advantages that: the scraper top can enter the annular groove when being installed, so that the solidified strip-shaped slag layer is better crushed.

Drawings

FIG. 1 is a process flow diagram of example 1 of the present invention;

fig. 2 is a plan view of a heat absorbing member in embodiment 1 of the present invention;

FIG. 3 is a front view of a heat absorption head at a bulge at the top of a slag cylinder in embodiment 1 of the invention;

FIG. 4 is a left side view of the heat absorption head at the top projection of the slag pot in embodiment 1 of the present invention;

FIG. 5 is a front view of a heat absorption head at a bulge at the top of a slag cylinder in embodiment 2 of the invention;

FIG. 6 is a front view of a heat absorption head at a bulge at the top of a slag cylinder in embodiment 3 of the invention;

FIG. 7 is a left side view of a heat absorption head located at a projection of the top of a slag pot in embodiment 3 of the present invention;

fig. 8 is a front view of the heat absorption head at the top projection of the slag pot in embodiment 4 of the present invention.

Reference numerals in the drawings of the specification include: the device comprises a diversion trench 1, an electric cylinder 2, a permanent magnet 3, a roller 10, a hollow shaft 11, a bearing seat 12, a slag cylinder 13, a motor 14, a gear transmission mechanism 15, a barrier strip 16, a slag receiving hopper 17, a scraping seam 18 and a scraper 19.

Detailed Description

The following is further detailed by way of specific embodiments:

example 1:

substantially as shown in figures 1, 2, 3 and 4 of the accompanying drawings: the waste heat recovery system for steel smelting is arranged close to a smelting furnace, wherein a discharge hole for discharging and deslagging is formed in the bottom of the smelting furnace; the waste heat recovery system in this embodiment includes frame, guiding gutter 1, heat absorption subassembly, slag cylinder 13, granulator, lifting conveyor, secondary heat transfer system and band conveyer, and wherein secondary heat transfer system can adopt horizontal rotary kiln or vertical cooling kiln, adopts vertical cooling kiln in this embodiment.

One end of the diversion trench 1 is located below the discharge port, the other end of the diversion trench is located above the slag cylinder 13, one side of the diversion trench 1, which is close to the slag cylinder 13, is hinged to the frame, the frame is provided with an electric cylinder 2 which drives the diversion trench 1 to swing around a hinge point, the diversion trench 1 is arranged in an inclined manner, and one end of the diversion trench 1, which is close to the discharge port, is located above one end of the slag cylinder 13.

The heat absorption assembly comprises three heat absorption heads, wherein each heat absorption head comprises a hollow roller 10 and two hollow shafts 11, the two hollow shafts 11 are respectively and coaxially fixed at two ends of the roller 10, so that the hollow shafts 11 are communicated with the interior of the roller 10, the hollow shafts 11 and the interior of the roller 10 are used for heat absorption medium to pass through, a bearing seat 12 is fixedly arranged on the rack, a ball bearing is arranged in the bearing seat 12, the hollow shafts 11 are horizontally fixed in the ball bearing, namely the hollow shafts 11 and the roller 10 are horizontally and rotatably connected to the rack; a plurality of barrier strips 16 are arranged on the roller 10, and the barrier strips 16 are uniformly distributed along the circumferential direction of the outer wall of the roller 10.

The slag cylinder 13 is arranged below the roller 10, the transverse section of the slag cylinder 13 is in a convex shape, one heat absorption head is positioned at the convex part at the top of the slag cylinder 13, the other two heat absorption heads are positioned at the convex parts at two sides of the slag cylinder 13, slag discharged from the smelting furnace enters the slag cylinder 13 through the diversion trench 1, and the roller 10 in the heat absorption heads is partially immersed in molten slag in the slag cylinder 13.

The rack is also provided with a motor 14 and a gear transmission mechanism 15, wherein the motor 14 is fixed on the rack through the base, the gear transmission mechanism 15 comprises a driving gear and a driven gear, the driven gear is coaxially fixed on one of the hollow shafts 11, the driving gear is fixed with an output shaft of the motor 14, the driving gear is meshed with the driven gear, the wheel diameter of the driving gear is smaller than that of the driven gear, and thus the motor 14 drives the hollow shaft 11 to rotate at a slow speed through the gear transmission mechanism 15.

Three slag receiving hoppers 17 are further arranged at the top of the granulator, each slag receiving hopper 17 is arranged close to the roller 10 of the heat absorption head, in addition, in the embodiment, the side wall of the slag receiving hopper 17 far away from the roller 10 is higher than the side wall of the slag receiving hopper 17 near the roller 10, and the permanent magnet 3 is fixed on the side wall of the slag receiving hopper 17 far away from the roller 10, and the rotating direction of each roller 10 in the embodiment is the direction indicated by the arrow in fig. 1.

In this embodiment, after a stove is smelted to the smelting furnace completion, make guiding gutter 1 leave the discharge gate bottom through electric cylinder 2 earlier, treat the steel and iron solution discharge back, rethread electric cylinder 2 makes guiding gutter 1 swing to the bottom of discharge gate, the slag in the back smelting furnace is discharged through the discharge gate, enter into guiding gutter 1, and in getting into slag jar 13 along guiding gutter 1, because the slag temperature who discharges from the smelting furnace this moment is up to 1000 ~ 1600 ℃, therefore this in-process, the molten slag is difficult to condense, can flow into in slag jar 13 fast, by waste heat recovery and broken handle.

The molten slag entering the slag cylinder 13 is subjected to waste heat recovery through the heat absorption assembly, and the method specifically comprises the following steps: molten slag enters a slag cylinder 13 to ensure that the roller 10 is partially immersed in the solution, a motor 14 is started, a hollow shaft 11 in the three heat absorption heads and the roller 10 rotate synchronously, meanwhile, the cooling medium continuously flows from left to right or from right to left in the heat absorption head through an external circulating system, when the roller 10 rotates, the molten slag in the slag cylinder 13 is attached to the surface of the roller 10, and is continuously far away from the slag cylinder 13 along with the rotation of the roller 10, and is gradually solidified into a strip-shaped slag layer under the heat exchange effect of the cooling medium, even if the slag is solidified and agglomerated at the moment, due to the blocking of the barrier strips 16, the slag layer is not easy to peel off from the outer wall of the roller 10 and fall into the slag cylinder 13 again, when the molten slag moves to a side close to the slag receiving hopper 17, the strip-shaped slag layer falls into the slag receiving hopper 17 under the action of the self gravity, the centrifugal force of the roller 10 and the suction force of the permanent magnet 3, so that the waste heat recovery and the crushing treatment of the molten slag are completed.

Because the heat absorption head is equipped with threely in this embodiment, and the form of arranging of three heat absorption head, can make and to accomplish waste heat recovery and the broken handle of a large amount of melting slag simultaneously in the slag jar 13, such mode can reduce the problem that the slag is detained in the slag jar 13, thereby also reduce the accumulation that melting slag solidifies the formation, in addition when one of them heat absorption head need overhaul, two other heat absorption heads need not shut down, waste heat recovery and the broken handle of slag can not break off promptly, thereby made things convenient for the maintenance of whole heat absorption subassembly to overhaul.

Example 2:

as shown in fig. 5, the difference from embodiment 1 is that: in this embodiment, the barrier strips 16 are arc-shaped, that is, the planes of the two ends of the barrier strips 16 are not coincident with the plane of the middle part thereof, and the direction of the arc-shaped concave surface of each barrier strip 16 is the same as the rotation direction of the roller 10; the reason for this is that, when the heat absorbing head is working, the temperature of the roller 10 near the input end of the cooling medium is lower than that of the output end of the cooling medium, so the cooling speed of the molten slag attached to the input end is slightly higher than that of the molten slag attached to the other end, so the molten slag has a faster solidification speed on the outer wall of the roller 10 at the input end, the thickness of the slag layer solidified at the same time is larger than that of other parts, if the solidified thickness exceeds the height of the barrier strips 16, the barrier effect of the barrier strips 16 is limited, therefore, by adopting the scheme, the molten slag has a tendency of flowing towards the middle of the barrier strips 16, and the tendency of the molten slag layer to be solidified into a thicker slag layer at the end parts of the roller 10 is reduced.

Example 3:

as shown in fig. 6 and 7, the difference from embodiment 1 is that: in this embodiment, each barrier strip 16 is provided with one or more scraping seams 18, in this embodiment, the number of the scraping seams 18 is two, the width of the scraping seam 18 is less than 10mm, the adjacent scraping seams 18 on the upper and lower adjacent barrier strips 16 are located on the same circumferential line of the roller 10, in addition, a scraper 19 is fixed on one side of the slag receiving hopper 17 close to the slag cylinder 13, the number of the scrapers 19 is consistent with the number of the scraping seams 18 on the barrier strips 16, that is, in this embodiment, the two scrapers 19 are provided, the top of the scraper 19 is close to the outer wall of the roller 10 and can pass through the scraping seams 18, so that when the strip-shaped slag layer solidified on the roller 10 rotates to the side close to the slag receiving hopper 17, the strip-shaped slag layer is cut off by the action of the scraper 19, and the strip-.

Example 4:

substantially as shown in figure 8: the difference with embodiment 3 is that in this embodiment, an annular groove is formed in the outer wall of the roller 10 along the circumferential direction thereof, and the annular groove communicates with the vertically adjacent scraping seams 18, so that the top of the scraper 19 can enter the annular groove when being installed, and the solidified strip-shaped slag layer can be better crushed.

The foregoing is merely an example of the present invention and common general knowledge of known specific structures and features of the embodiments is not described herein in any greater detail. It should be noted that, for those skilled in the art, without departing from the structure of the present invention, several changes and modifications can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.

Claims

1. Waste heat recovery system for steel smelting, the smelting furnace setting that has the discharge gate near the bottom, including frame, heat absorption subassembly, sediment jar, granulator, promotion conveyer, secondary heat transfer system and band conveyer, the heat absorption subassembly includes heat absorption head, and heat absorption head includes hollow roller and two hollow shafts, and two hollow shafts are coaxial fixation respectively at the both ends of roller, and two hollow shafts rotate to be connected in the frame, and the sediment jar sets up in the below of roller, its characterized in that: the granulator comprises a granulator body, and is characterized in that a diversion trench is arranged on the machine frame, one end of the diversion trench is located below a discharge port, the other end of the diversion trench is located above a slag cylinder, one side, close to the slag cylinder, of the diversion trench is hinged to the machine frame, a driving piece for driving the diversion trench to swing around a hinged point is arranged on the machine frame, a plurality of blocking strips are arranged on a roller, the blocking strips are evenly distributed along the circumferential direction of the outer wall of the roller, a slag receiving hopper is further arranged at the top of the granulator body, and.

2. The heat recovery system for iron and steel smelting according to claim 1, characterized in that: the guiding gutter sets up for the slope, and the guiding gutter is close to discharge gate one end and is located the top that is close to slag cylinder one end.

3. The heat recovery system for iron and steel smelting according to claim 1, characterized in that: the side wall of the slag receiving hopper far away from one side of the roller is higher than the side wall of the slag receiving hopper near one side of the roller, and a permanent magnet is fixed on the side wall of the slag receiving hopper far away from one side of the roller.

4. The heat recovery system for iron and steel smelting according to claim 1, characterized in that: the three heat absorption heads are arranged, the transverse cross section of the slag cylinder is in a convex shape, one heat absorption head is positioned at the convex part at the top of the slag cylinder, and the other two heat absorption heads are positioned at the convex parts at the two sides of the slag cylinder.

5. The heat recovery system for iron and steel smelting according to claim 4, characterized in that: the barrier strips are arc-shaped, planes of two ends of the barrier strips are not overlapped with a plane of the middle of the barrier strips, and the orientation of the arc-shaped concave surface of each barrier strip is the same as the rotation direction of the roller.

6. The heat recovery system for iron and steel smelting according to claim 4, characterized in that: the scraping seam has been seted up on the blend stop, and the scraping seam on the upper and lower adjacent blend stop is located the same circumference line of roller, connects the sediment fill to be close to slag jar one side and is equipped with the scraper, and the top of scraper is close to the outer wall of roller and can follow the scraping seam and pass through.

7. The heat recovery system for iron and steel smelting according to claim 6, characterized in that: the barrier strip is provided with a plurality of scraping seams, and the corresponding scrapers are also provided with a plurality of scrapers.

8. The heat recovery system for iron and steel smelting according to claim 7, characterized in that: the outer wall of the roller is provided with an annular groove along the circumferential direction, and the annular groove is communicated with the vertically adjacent scraping seams.