CN-117363818-B - Method for additionally installing furnace shell hoop for preventing furnace shell from cracking

CN117363818BCN 117363818 BCN117363818 BCN 117363818BCN-117363818-B

Abstract

A method for preventing furnace shell from cracking and installing furnace shell hoops comprises the following steps of S1, firstly constructing a hoop device, S2, respectively installing a plurality of layers of uniformly distributed first rib plates and second rib plates outside a hot blast stove and an air mixing chamber along the circumferential direction, placing a first fixing piece on the first rib plates and a second fixing piece on the second rib plates, S3, after the baking is finished, screwing the segmented first fixing piece and the segmented second fixing piece together through bolts after the hot blast stove and the air mixing chamber enter a normal production state, and then connecting the first fixing piece and the second fixing piece together through a pull rod. The method is simple, convenient to operate and low in cost, thoroughly solves the design defects of the rigid hoops and the rigid connecting pull rods, and the expansion and contraction of the furnace shell and the up-and-down expansion and contraction of the furnace shell are in a loose free state, thoroughly solves the cracking limit of the furnace shell, avoids the cracking of the furnace shell, and has remarkable social and economic benefits.

Inventors

ZHANG FUMING
LI XIANWU
CUI FANGHUI
LIU DONGPEI
AO AIGUO
ZOU DONGPING
GUO XIANZHEN
QIAN SHICHONG
WU HUIQING
ZHANG FENG
FU ZHENGXUE
LI YINGXIN

Assignees

郑州豫兴热风炉科技有限公司
河南省豫兴热风炉工程技术有限公司

Dates

Publication Date: 20260508
Application Date: 20231121

Claims (4)

1. The method for preventing the furnace shell from cracking and additionally installing the furnace shell hoop is characterized by comprising the following steps of: S1, firstly, constructing a hoop device, wherein the hoop device comprises a first fixing piece (1) and a second fixing piece (2), the first fixing piece (1) and the second fixing piece (2) are round formed by a plurality of sections of arc plates connected through bolts (3), a first connector (101) and a second connector (201) are respectively arranged on the arc plates opposite to the first fixing piece (1) and the second fixing piece (2), the first connector (101) and the second connector (201) are connected together through a pull rod (4), and then a hoop is additionally arranged according to the following method; S2, a first rib plate (7) and a second rib plate (8) which are uniformly distributed in multiple layers are additionally arranged outside the hot blast stove (5) and the air mixing chamber (6) along the circumferential direction respectively, a first fixing piece (1) is placed on the first rib plate (7), a second fixing piece (2) is placed on the second rib plate (8), a bolt (3) is unscrewed firstly, at the moment, the first fixing piece (1) and the second fixing piece (2) are in loose connection with the outer walls of the hot blast stove (5) and the air mixing chamber (6), and the calculation formula of the inner diameters of the first fixing piece (1) and the second fixing piece (2) is as follows: Expansion amount=temperature×linear expansion coefficient α×furnace shell circumference 1 Hoop inner diameter D= (furnace shell perimeter+expansion amount)/pi-type 2 Wherein, the expansion amount, D and the circumference of the furnace shell are in mm, the temperature is in DEG C, the linear expansion coefficient alpha=12×10 -6 , pi is 3.14; S3, after the baking furnace is finished and the hot blast furnace (5) and the air mixing chamber (6) enter a normal production state, the segmented first fixing piece (1) and the second fixing piece (2) are screwed and connected together through bolts (3), at the moment, the first fixing piece (1) and the second fixing piece (2) are tightly connected with the outer walls of the hot blast furnace (5) and the air mixing chamber (6), and then the first fixing piece (1) and the second fixing piece (2) are connected together through the pull rod (4), so that the hoop device is firmly additionally arranged on the furnace shell, and the cracking of the furnace shell is effectively prevented.
2. The method for preventing the cracking of the furnace shell and installing the furnace shell hoop according to claim 1, wherein the pull rod (4) comprises a first connecting rod (401), a second connecting rod (402), a connecting shaft (403) and a stud bolt (404), the end parts of the first connecting rod (401) and the second connecting rod (402) are respectively arranged on the first connecting head (101) and the second connecting head (201) through the connecting shaft (403), and the other end parts of the first connecting rod (401) and the second connecting rod (402) are connected with the stud bolt (404) through screw threads.
3. The method for preventing the cracking of the furnace shell and additionally installing the furnace shell hoop according to claim 1, wherein the first fixing piece (1) is a round formed by sequentially connecting more than 2 sections of arc plates end to end through a first bolt (301), and the second fixing piece (2) is a round formed by sequentially connecting more than 2 sections of arc plates end to end through a second bolt (302).
4. The method for preventing the cracking of the furnace shell and installing the furnace shell hoop according to claim 2, wherein the first connector (101) and the second connector (201) have the same structure and are in a right-angle groove shape, and connecting shafts (403) for connecting the first connecting rod (401) and the second connecting rod (402) are arranged on two symmetrical side walls of the groove.

Description

Method for additionally installing furnace shell hoop for preventing furnace shell from cracking Technical Field The invention relates to the field of hot blast stoves, in particular to a method for preventing a stove outer covering from cracking and additionally installing a stove outer covering hoop. Background At present, common cracking phenomenon appears on the shells of high-pressure high-wind-temperature hot blast stoves of blast furnaces, and personal safety of the hot blast stoves and workers is seriously influenced. In addition to the factors of discovered furnace shell material defects, insufficient furnace shell resistance thickness, stress concentration, slightly changed yield of welding seams and heat affected zone, changed hardness, nitrate generated by high-temperature air in the air supply period and thousands of PPM in the air supply period, and the like, the furnace shell cracking of the hot-blast furnace also has an industry neglected factor, the furnace shell variable caused by the air supply pressure of the furnace shell is strengthened to firmly weld the reinforcing hoop on the furnace shell of the hot-blast furnace, a rigid connection structure is formed, the arranged rigid hoop structure leads to the gradual expansion of the furnace shell in the heating period of the hot-blast furnace to the normal production period to be limited by the reinforcing hoop and can not be expanded and contracted, the furnace shell outside the hoop area is free to be expanded, the furnace shell can not be completely and freely expanded and contracted, the furnace shell is also limited to be expanded upwards by the connecting rod of the hoop and the transverse connection, and the two factors are neglected factors causing the cracking of the furnace shell, and the furnace shell expansion value is calculated according to the standard 12×10 -6 in the present cracking case: Furnace shell hoop limited circumferential expansion amount of furnace shell: In the first case, the inner diameter of a straight section furnace shell of an safety steel hot air outlet is 11260mm, the temperature of the furnace shell is 80 ℃, the circumferential expansion amount is 33.96mm, the temperature of the furnace shell is 100 ℃, the circumferential expansion amount is 42.45mm, the temperature of the furnace shell is 120 ℃, the circumferential expansion amount is 50.94mm, and the temperature of the furnace shell is 150 ℃ and the circumferential expansion amount is 63.67mm. In the second case, the inner diameter of a straight section furnace shell of a Zhanjiang hot air outlet is 12590mm, the temperature of the furnace shell is 80 ℃, the circumferential expansion amount is 37.97mm, the temperature of the furnace shell is 100 ℃, the circumferential expansion amount is 47.46mm, the temperature of the furnace shell is 120 ℃, the circumferential expansion amount is 56.96mm, and the temperature of the furnace shell is 150 ℃ and the circumferential expansion amount is 71.19mm. In case three, the inner diameter of a straight section furnace shell of a Jing Tang hot air outlet is 13520mm, the temperature of the furnace shell is 80 ℃, the circumferential expansion amount is 40.77mm, the temperature of the furnace shell is 100 ℃, the circumferential expansion amount is 50.97mm, the temperature of the furnace shell is 120 ℃, the circumferential expansion amount is 61.16mm, and the temperature of the furnace shell is 150 ℃ and the circumferential expansion amount is 76.45mm. Furnace shell hoop limited upward expansion amount of furnace shell: for example, the rigid connection of the anchor ear and the pull rod of the blast furnace hot blast stove with the safety steel 4747m3 limits the upward expansion amount of the furnace shell, namely, assuming that the average furnace shell temperature is 70 ℃, the height from the furnace bottom to a hot blast outlet is 32.1m, the expansion amount is about 26.96mm, the height from the furnace bottom to the furnace top is 51.54m, the expansion amount is 43.29mm, the average furnace shell temperature is 100 ℃, the expansion amount from the furnace bottom to the hot blast outlet is about 38.52mm, and the expansion amount from the furnace bottom to the furnace top is 61.86mm. 2. The rigid connection of the Baohan river 5050m3 blast furnace hot blast stove hoop and the pull rod limits the upward expansion amount of the furnace shell, wherein the average furnace shell temperature is 70 ℃, the expansion amount from the furnace bottom to the hot blast outlet is about 23.27mm, the expansion amount from the furnace bottom to the furnace top is about 48.3m and 40.57mm, the average furnace shell temperature is 100 ℃, the expansion amount from the furnace bottom to the hot blast outlet is about 33.24mm, and the expansion amount from the furnace bottom to the furnace top is 57.96mm. 3. The rigid connection of the anchor ear and the pull rod of the Jing Tang 5500m3 blast furnace hot blast stove limits the upward expansion