CN110701911A

CN110701911A - Baking furnace building process

Info

Publication number: CN110701911A
Application number: CN201910969968.8A
Authority: CN
Inventors: 蔡锦林
Original assignee: Gaoyou Jineng Refractory Factory
Current assignee: Gaoyou Jineng Refractory Factory
Priority date: 2019-10-12
Filing date: 2019-10-12
Publication date: 2020-01-17

Abstract

The invention relates to a baking furnace building process, which comprises the following process steps: firstly, building a furnace; secondly, baking the furnace; (III) opening the furnace for smelting; (IV) maintaining the furnace; fifthly, discharging the first furnace molten iron; and (VI) starting the cooling furnace. The invention has the characteristics of high refractoriness, good slag resistance, stable high-temperature volume, wear resistance, scouring resistance and simple and convenient construction operation, and is particularly environment-friendly with less solid garbage generated in use.

Description

Baking furnace building process

Technical Field

The invention relates to the technical field of furnace construction of refractory materials, in particular to a furnace construction process.

Background

Refractory material is by the cupola furnace of wide application in traditional casting smelting trade, intermediate frequency furnace, transfer ladle etc. and traditional furnace process of building is comparatively complicated, and the construction is got up comparatively trouble, and the preparation finished product contains impurity, and the layering takes place even after the long-term high temperature easily fracture simultaneously, influences the life of furnace body, and the problem that has now is solved to a new refractory material of building furnace process is waited for urgently.

Disclosure of Invention

The invention aims to solve the technical problem of providing a baking furnace building process.

In order to solve the technical problems, the technical scheme provided by the invention is as follows: a baking furnace manufacturing process comprises the following process steps:

(I) building a furnace: furnace front cleaning and preparation of furnace building:

1) and furnace front cleaning: after a new furnace or an old furnace is dismantled in front of the furnace, the furnace is cleaned and kept clean, the new furnace is dried to remove moisture so as to be dry, and meanwhile, the working site of the electric furnace needs to be kept clean to prevent impurities from being brought into a hearth or mixed into a furnace lining material;

2) and manufacturing a crucible: the method is characterized in that a tapered crucible is made of a thin iron plate, the thickness of the thin iron plate is determined by the tonnage of an electric furnace, but the thin iron plate must have certain strength to prevent cracking after high temperature, so that the service life of the crucible is greatly related to refractory materials, furnace building, furnace baking processes and operation, use and management, four major elements are fastened in a ring mode, one of the four major elements is unavailable, a certain radian is required to be arranged at the bottom of the crucible in a 6-12 cm mode, the radian is in direct proportion to the tonnage of the electric furnace, the crucible is smooth in one circle and at the bottom, and is provided with air holes, the air holes are uniformly distributed, the upper distance and the lower distance are 150mm, the left distance and the right distance are 200mm, the diameter of the air holes is 3.5mm, the size of the;

3) preparing a furnace lining material and a furnace building tool: the furnace lining material is required to be packaged completely, moisture-proof and anti-cracking, the dosage of each furnace is sufficient, the quality of the furnace lining material is ensured, a furnace building tool is used for ensuring the safety in use, and whether the electrification is normal is checked;

4) the requirements of furnace building, furnace bottom and furnace wall are as follows: firstly, determining the thickness of a furnace bottom, wherein the furnace bottom requires one-time feeding, one-time tamping vibration and repeated feeding, so that the layering is prevented, the service life of the furnace is influenced, the furnace wall is fed in times, and the repeated tamping vibration is suitable, one-time feeding is generally 100mm-150mm, the furnace bottom and the furnace wall require uniform vibration layer by layer when in tamping vibration until the furnace wall is compacted, the uneven vibration cannot be realized, the surface layer of the uppermost layer is scratched after one-layer vibration, and then feeding vibration is carried out, so that the layering phenomenon can be avoided between layers, and so on until the furnace wall is built;

(II) baking the furnace:

1) the crucible is filled with smelting materials at one time, the first three furnaces require the use of low-carbon, low-alloy, rust-free or rust-less clean furnace burden, so that the furnace lining is not corroded, the surface is smooth and convenient to sinter, the furnace wall is required to be covered for a circle during charging, and the situation that scrap iron or impurities fall into the furnace wall which is not built during charging to cause artificial unsuccessful furnace building loss is prevented;

2) heating: the crucible is well covered before heating and baking the furnace, the heat emission during the baking is prevented, the sintering on the furnace mouth is not ideal enough, and the heating is uneven, the direct current is electrified for 0-100A hour, 100-200A hour, 300-500A hour and 500-600A five hours, the melting point of the unmelted molten iron is controlled, the direct current voltage is 80-100V at the moment, the baking time of 8 hours is ensured, and the baking time of 3-10 tons of the electric furnace is required to be prolonged for 3-5 hours;

(III) blow-in smelting: after the furnace is dried for 8 hours, the current is gradually increased for 800A fifteen minutes at first and for 850A fifteen minutes at first, and then a certain current is properly increased for smelting to supplement the furnace burden in the crucible;

(IV) maintaining the furnace: when the first furnace is full of molten iron, performing furnace maintenance sintering, requiring the molten iron to be maintained in the furnace for 1.5-2 hours, measuring the temperature of the molten iron in the furnace by using a temperature gun, controlling the temperature between 1300 ℃ and 1500 ℃, stabilizing the current and the voltage, and achieving the best time for maintaining the furnace;

(V) discharging first furnace molten iron:

1) and preparing before discharging: before discharging, preparing the furnace charge of the next furnace, requiring the furnace charge to be discharged after the next furnace charge is in place, and placing the material with small furnace charge on the upper surface of the previous batch so as to execute the principle that the furnace charge cannot be broken by adding small materials and then adding large materials when starting charging;

2) the molten iron is discharged from the first furnace body, generally the molten iron is discharged twice preferably, the molten iron is 30-50% in the first time, then the molten iron is fed and smelted, and the molten iron is discharged after the molten iron is full, but the molten iron in each furnace needs to be 150-200 kg at the bottom and does not need to be completely discharged, so that the smelting time of the next furnace can be accelerated; if no production is carried out any more in the day, the molten iron is completely bright;

(VI) starting a cooling furnace: the cold furnace needs to be slowly and gradually heated for 2-3 hours when started, the current and the voltage are gradually increased, and the operation is carried out according to the principle that small materials are firstly added, then large materials are added, the furnace lining can not be broken by smashing and the materials are carefully and lightly placed when added.

Further, whether the coil is deformed, whether a cooling water path is smooth and whether a power supply is normal are required and checked in the step (one) -1).

Further, when the molten iron in the step (IV) is maintained in the furnace, the furnace maintenance time of the electric furnace of 3-10 tons needs to be prolonged by 2 hours.

The invention has the following advantages: the invention has the characteristics of high refractoriness, good slag resistance, stable high-temperature volume, wear resistance, scouring resistance and simple and convenient construction operation, and is particularly environment-friendly with less solid garbage generated in use.

Detailed Description

The present invention will be described in further detail with reference to examples.

A baking furnace manufacturing process comprises the following process steps:

1) and furnace front cleaning: after a new furnace or an old furnace is dismantled in front of the furnace, the furnace is cleaned and kept clean, whether a coil is deformed or not, whether a cooling water path is smooth or not and whether a power supply is normal or not are required to be checked, the new furnace is dried to remove moisture so as to be dried, and meanwhile, the working site of the electric furnace is required to be kept clean to prevent impurities from being brought into a hearth or mixed into a furnace lining material;

electric furnace tonnage	Size of furnace bottom (mm)	Furnace wall size (mm)
			1	280-300	90-100
1.5	300-320	100-110
			2	320-330	110-120
3	330-350	120
			5	350-380	130
10	380-400	135

Note: the wall of the tap hole is required to be thicker than the walls of the other peripheral walls by 1.5 mm.

(II) baking the furnace:

(IV) maintaining the furnace: when the first furnace is full of molten iron, furnace maintenance sintering is carried out, the molten iron is required to be maintained in the furnace for 1.5-2 hours, the furnace maintenance time of an electric furnace of 3-10 tons needs to be prolonged for 2 hours, a temperature gun is used for measuring the temperature of the molten iron in the furnace and controlling the temperature between 1300 ℃ and 1500 ℃, the current and the voltage are stabilized, and the furnace maintenance time is optimal;

(V) discharging first furnace molten iron:

Although the invention has been described in detail hereinabove with respect to a general description and specific embodiments thereof, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims

1. A baking furnace manufacturing process is characterized by comprising the following process steps:

1) and furnace front cleaning: after a new furnace or an old furnace is dismantled in front of the furnace, the furnace is cleaned, the new furnace is dried to remove moisture so as to be dry, and meanwhile, the working site of the electric furnace needs to be kept clean to prevent impurities from being brought into a hearth or mixed into a furnace lining material;

2) and manufacturing a crucible: the method is characterized in that a tapered crucible is made of a thin iron plate, the bottom of the crucible is required to have a certain radian in 6-12 centimeters, the radian is in direct proportion to the tonnage of an electric furnace, the crucible is smooth in one circle and the bottom and is provided with air holes, the air holes are uniformly distributed, the vertical distance is 150mm, the horizontal distance is 200mm, the diameter of each air hole is 3.5mm, and the size of the crucible is determined according to the tonnage of the electric furnace;

4) the requirements of furnace building, furnace bottom and furnace wall are as follows: firstly, determining the thickness of a furnace bottom, wherein the furnace bottom requires one-time feeding, one-time tamping vibration, and the bottom is fed in times to prevent layering and influence the service life of the furnace, the furnace wall is fed in times, and the vibration is suitable for the tamping in times, wherein one-time feeding is generally 100mm-150mm, and the furnace bottom and the furnace wall require uniform vibration layer by layer when in tamping vibration until the furnace wall is compacted, and after one layer is vibrated, the surface layer on the uppermost layer is scratched, and then feeding vibration is carried out, and so on in sequence until the furnace wall is built;

(II) baking the furnace:

1) the crucible is filled with smelting materials at one time, the first three furnaces require to use clean furnace materials with low carbon, low alloy, no rust or less rust, and the furnace wall is required to be covered for a circle during charging so as to prevent scrap iron or impurities from falling into the furnace wall which is not built;

2) heating: covering the crucible before heating and baking the furnace, electrifying direct current for 0-100A hour, 100-200A hour, 300-500A hour and 500-600A five hours, controlling the direct current voltage between the melting points of the unmelted molten iron, ensuring the baking time of 8 hours, and prolonging the baking time of 3-10 tons of electric furnace for 3-5 hours;

(IV) maintaining the furnace: when the first furnace is full of molten iron, performing furnace maintenance sintering, requiring the molten iron to be maintained in the furnace for 1.5-2 hours, measuring the temperature of the molten iron in the furnace by using a temperature gun, controlling the temperature to be between 1300 ℃ and 1500 ℃, and stabilizing the current and the voltage;

(V) discharging first furnace molten iron:

1) and preparing before discharging: before discharging, preparing the furnace burden of the next furnace, requiring the furnace burden to be discharged after the next furnace burden is in place, and placing the material with small furnace burden on the upper surface of the previous batch so as to perform the steps of adding the small material and then adding the large material when starting charging;

2. A furnace construction process according to claim 1, wherein: and (2) in the step (one) -1), whether the coil is deformed, whether the cooling water path is smooth and whether the power supply is normal are required and checked.

3. A furnace construction process according to claim 1, wherein: and (3) when the molten iron in the step (IV) is maintained in the furnace, the furnace maintenance time of the electric furnace of 3-10 tons needs to be prolonged by 2 hours.