Guanzeng Li Yuqi Zhang Jincao

　　Abstract: The seal of sinter is a difficult problem in sintering industry, the eight sinters of Capital Steel has been used for many years. Leaking air always is a serious problem. For this reason, it not only wastes energy, but also infects the quality and output of sintering mine. We adopt the sinter seal new technology of Beijing Jindu Metallurgy Mechanism Mill to change the four sinters' trolley and sinter head & end seal in No.1 workshop. It has good effect. At present, it has been applied in produce formally.

Keywords: Sinter Seal; Trolley Seal; Head & End Seal

　　 Preface

Capital Steel Puddling Mill has eight sinters, among them, five are 90m 2, three are 75m 2. Because tight material, we have not given a heavy repair. Leaking wind is very serious, not only wastes energy (mainly waste electricity), but also infects the quality and output of sintering mine. So we do a series of exploration and practice.

　　We pay more attention to the blocking and leaking wind of sinter in daily produce, especially blocking and leaking wind about convulsions system and controlling the cinerary, but the leaking wind of sinter, including the leaking wind between trolley slideway and fix slideway and the leaking wind of head and end machine, have not solved for long time. Therefore, we collaborated with Beijing Jindu Metallurgy Mechanism Mill in 2004; we researched the trolley slidway of sinter and the seal board of head and end machine together; we also reconstruct the four-sinter trolley and head and end machine in No.1 workshop while we repaired. The trolley slideway of sinter adopts the patent technology of Beijing Jindu Metallurgy Mechanism Mill, SB sinter trolley double spring seal slideway (patent No. 01220108.1 ); the head and end seal adopts mature parallel bars head and end seal patent technology (Patent No. 02281664.x ). The leaking wind rate has decreased obviously after reconstructing; the output has increased; many craft parameters' change indicates the effect of reconstruction.

§ 1 Before reconstruction

There are four 90m 2 cooling sinters in a workshop, we reconstructed the four sinters with seal technology while repaired in 2004.

§ 1.1 the reconstruction situation of trolley sliding plate seal

Before reconstruction, the trolley sliding plate seal of No.1 workshop is spring seal; installing it on the two sides of trolley; pressing the trolley slideway on the fixing slideway depending on the bounce of circle spring; making trolley slideway and fixing slideway closely; and then it can seal perfectly.

The defect of this method: first: the seal device on the two sides of the trolley adopts wire-helix springs; there is 1mm gap between the slideway plate and slideway channel in order to keep the slide board sliding freely, and then form a board to leak air (see the following picture). The leaking wind area of a 90 mm 2 is about 60000mm 2 between the slidway board and slideway channel; it is equal to a hole that the length is 1m and the width is 60 mm. Second, it will pin the seal board when the board is distortion; and then infect the effect of seal; with the times lapse, the springs will lose springiness; and then decrease the effect of seal.

Circle Spring

1mm 间隙

the flowing orientation of the air

We change the old trolley slideway into the SB type trolley double spring seal slidway that adopts the patent technology of Beijing Jindu Metallurgy Mechanism Mill. The character as following:

a) The SB type trolley double spring seal slidway installs two spring between the upper cover of the slideway and glide swimming board, and the two springs was riveted with glide swimming board and the upper cover of the slideway, and then diminish the leaking wind between the glide swimming board and the upper cover of the slideway.

b) Because the two springs press the slideway board at the same time, the sliding board is pressed uniformly; it can guarantee the close between the glide swimming board and the fixed slideway, and then improve the effect of seal.

c) SB trolley double spring slideway's externality is same with the common slideway's externality, can interconvert with old slidway. It is convenient when you examine or repair.

In the reconstruction of the two sinters, in order to make the seal reach the best effect between the trolley slideway board and the fixed slideway, we adjust each slideway's standard as 4mm according to the abrasion of each sinter.

We examine matching situation between the new trolley sliding board and fixed slideway while we examine and repair the trolley. Because of old trolley, the different abrasion cause the different size of the trolley wheel, and then make the condensation of the trolley different; now, the condensation of the trolley sliding board is 2~8mm; it satisfies the seal demand of the trolley sliding board. After the sinter start, we can observe that the noise of leaking wind decrease greatly.

§ 1.2After reconstructing the head and end seal board

The head and end seal board adopts that spring support seal board before reconstruction; at the early days of the device used, it has good effects; after a period of time, the gravity and high temperature decrease springiness of spring; and then make the seal board not float; the gap between the bottom of the trolley and the seal board increase; plenty of wind come in; and then cause heavy wind.

The picture of old-style head and end seal device as follow:

Seal board

Circle spring

The mature parallel bars head and end seal technology that was developed by Beijing Jindu Metallurgy Mechanism Mill can decrease leaking wind of head and end. Its character as follow:

Parallel bars sinter head and end seal device depends on the two levers which lift the seal board, and then make the seal board contact with the bottom of the trolley. The two pivots of the levers not only move point but also the seal point.

The sketch map of the structure

The situation of construction at the spot

2 the prime effect of application

In order to validate the seal of the reconstruction, we organize the result of leaking wind rate about the four sinters before and after reconstruction. At the same time, we also arrange the craft parameter before and after reconstruction. We just arrange the No.4 sinter's data, the concrete data as follow:

§ 2.1 4# the situation of No.4 sinter

§ 2.1.1 the checking result of leaking wind rate about No.4 sinter before and after reconstruction

the checking result before reconstruction

the checking result of the leaking wind rate after reconstruction

Analyze: After the reconstruction, the system leaking wind of sinter has changed from 56.77 ％ to 41.64 ％, the noumenon leaking wind rate of sinter has changed from 52.74 ％ to 35.57 ％.

§ 2.1.2 4# The change of main parameter after reconstruction

In order to research the change of craft parameter after reconstruction, we arrange the output before reconstruction and after construction, the concrete data as follow:

Analyze: Because the leaking-wind rate decrease after reconstruction, the velocity is improved from 1.16m/m to 1.26m/m; the output of every sinter improve 8.6 ％ ; It has obvious benefit; it excludes other factors' effect; we can decrease the leaking wind rate through reconstruction, and then improve the output of sinter about 4%. Because the leaking wind rate has decreased, the pressure in sintering part has improved from 5430pa to 5670pa after reconstruction. Because the leaking wind has declined, the temperature of total pipeline has increased from 102 ℃ to 122℃, increasing 20℃. At the same time, because the harm leaking wind decreased, the utilizing of effective wind increased; so the pressure in cool part has decrease (about 640 pa), and the wind accelerate, (improve about 1204m 3/m). the speed of sinter improves about 0.11m/s.

§ 2.2 The reconstruction of other three sinters

Other three sinters also were reconstructed; the situation is similar with No.4 sinter; the system leaking wind rate decrease below 45%, the sinter noumenal leaking wind rate decrease below 40%.

§ 2.3

Analyze: both the output and the coefficient of sinter increase, the daily output increase 129t. The waste of electricity decrease 1.41kwh/t. the quality of sinter also improve.

3 Some problems in reconstruction

§ 3.1 、 Because of the reconstruction of seal, the lubricating system of sinter has reconstructed, but the former lubricating system reserve the traditional lubricating system, so the different lubricating point has different position, different distance from oil pump and different resistance; Maybe there is not enough oil; some has more; some has less, even has not any; if under the situation, it can't lubricate the fixed slideway well; some times there is dry rub between the trolley sliding board and sinter fixed slideway in some part; it not only decrease the seal, but also decrease the life of the sliding board; So we reconstruction the sinter lubricating system with intelligent lubricating technology; and then we get those character: firstly, offering oil point by point, that is to say, we supply oil according to procedure and order. The lubricating pump just offer oil for a point in unit time; secondly, checking point by point, in other word, checking the shifting signal in pipeline, and then reflecting the situation of lubricating character; thirdly, judging the trouble intelligently can judge the trouble of every lubricating point and lubricating component.

At present, it has been used in No.3 sinter of No.1 workshop, it has good effect and get good lubricant effect; we will reconstruct the rest sinters in No.1 workshop.

§ 3.2 、 We should consider every detail in the process of reconstruction, we find No.2 sinter end seal board fretted seriously when the device run. After examination, we find that the main reason, the material can't go easily after pressurizing the board; and then the finished products was blocked on the seal board. The grain of sinter rub, erode the seal board for the long time, and then effect the life of the seal board. We will draw a lesson in the following reconstruction, and then solve the problem.

Besides, we find that the trolley board was crashed while the seal device run; the reason of the phenomenon is old trolley, some trolley has been fretted about 1m; although we have considered the problem before we design, but because of the big abrasion, it also make some trolley sliding board longer then the trolley body, under the situation, it can make few sliding board crashed while the trolley pass the bending road. Therefore, we demand the length of the sliding board longer than the trolley body about 1mm when we process the trolley sliding board.

§ 3.3 、 the seal of sinter is a whole system, in daily work, we should strengthen the daily operation management, for example, strengthen the end discharge the ash valve; Strengthen examination to the slideway lubricant; adjust the sinter's deviation; avoid leaking wind. It not only decrease leaking wind, but also guarantee the seal device that can run for long time, and then make the sinter leak air scarcely in long time.

4 Conclusion

§ 4.1 The sinter leaking wind rate will decrease below 40 ％ according to the technical reconstruction of sinter seal; the system of sinter's leaking wind rate reach below 45%. That is to say, it is effective to decreasing the leaking wind rate of sinter that the reconstruction to trolley slideway, fix slideway and head and end seal

§ 4.2 It improve the output and save the energy according to technical reconstruction of the sinter seal; the output of sinter improve about 4%; at the same time, because the effective wind accelerate, the consume of electricity decrease about 1kwh per ton; the quality of sinter is also improved. The economic benefit is more obvious.