Automatic casting slag raking machine

Traditional slag raking relies on manual observation and control of related equipment operations and relies on manual experience to judge and control the slag raking path and depth. This can easily lead to long production times, serious iron loss, excessive or under-removal of slag, and no standard for iron residue in the ladle. To help the industry solve the above problems, our company independently developed an automatic slag raking system.

The automatic slag raking system is a comprehensive system based on intelligent slag raking machines, intelligent analysis, deep self-learning, neural networks and intelligent control, and can realize remote slag raking and remote operation and maintenance. Through the slag surface evaluation function of the automatic slag raking system, the system controls the slag raking machine to move according to the set path to realize automatic slag raking. It is an essential product for intelligent process production and management in the steel industry.

Standardize the operation process and stabilize the process cycle;
The production process can be traced to facilitate process upgrading;
Automatic slag raking frees the operator's hands.

This system mainly includes automatic slag removal, exception handling, and intelligent diagnosis.

1. Automatic casting slag raking part

This part contains seven subsystems, which completely constitute the automatic slag raking system.

slag remove System

The automatic slag raking system establishes communication with equipment such as slag skimming machines, hydraulic stations, desulfurization PLCs and tipping trucks, and controls the intelligent tipping of ladles and the slag skimming machines to operate according to planned paths, improving the stability of slag raking and eliminating the randomness of manual slag raking. It achieves the purpose of unified determination of the endpoint of slag raking, reducing iron loss and improving intelligent control.

1) Inclination sensor – detects the tipping angle of the ladle car.

2) Liquid level radar – detects the liquid level of molten iron.

3) Binocular vision cameras – No. 1 and No. 2 vision cameras. No. 1 vision camera: bale edge identification, slag surface identification, slag surface determination; No. 2 vision camera: path planning, tipping and overflow detection, and redundant design.

4) Remote camera – remote slag raking and large screen display in the operating room.

5) Surveillance cameras – monitor the entire slag raking operation platform to ensure personnel safety.

6) Vision Camera No. 3 – detects the amount of slag in the slag basin to ensure there is no overflow.

7) Displacement sensor – detects the stroke of the slag scraper cylinder.

8) Telescopic encoder – detects the telescopic distance of the slag scraper.

9) Rotary encoder – detects the rotation angle of the slag scraper.

Intelligent tipping of ladle

The intelligent slag-raking system detects the height of the molten steel level through radar, and automatically calculates the tipping angle based on the parameters of the ladle, thereby controlling the tipping angle of the ladle to a position conducive to slagging. At the same time, it monitors the molten steel level and the molten iron ladle in real time through the camera. When the edge position reaches the threshold position, tipping is forced to stop to ensure system safety.

During LTS slag skimming in the Second Steelmaking Plant, there is a molten slag pouring operation, and it is difficult to distinguish between molten slag and molten steel. In this project, automatic tipping can allow a certain degree of surface liquid slag to overflow and then tilt back. At the same time, the tilting angle can be manually intervened to discharge part of the liquid slag.

steelmaking, casting, casting slag

There is a movable fume hood on site. The ladle liquid level measurement and automatic slag raking process are completed before the fume hood moves into the workstation to avoid the detection interference of the fume hood on radar and visual cameras. It also standardizes the overall process flow of the LTS workstation: When the ladle enters the station, it first removes the slag, then conducts fume hood temperature measurement and sampling and bottom blowing of materials.

Slag Raking machine

The slag scraper has arm lifting, arm lowering, left-hand rotation, right-hand rotation, and slag scraper arm lifting and contraction movements. Each action is equipped with a position feedback sensor.

Function control:

All action controls of the slag scraper adopt a closed-loop control mode. This control method can not only ensure the smooth and reliable operation of the equipment but also ensure the positioning accuracy and meet the system requirements. The PLC module receives the path coordinate information transmitted by the slag raking path planning and converts it into the target position for telescopic, pitch, rotation, etc. control of the slag raking machine through the coordinate transformation algorithm, thus realizing the closed-loop control of the slag raking machine.

Renovation of telescopic motion control of slag raking machine

On the opposite side of the telescopic hydraulic motor, a non-contact encoder is mounted on the active sprocket shaft. By recording the number of rotations of the sprocket shaft during movement, the purpose of measuring the telescopic distance is achieved to ensure the safety and reliability of the main telescopic movement.

Modification of pitch action control of slag scraper

A pull cord encoder is installed outside the oil cylinder to detect the expansion and contraction stroke of the oil cylinder according to the displacement length of the pull cord and then converts it into a pitch angle to achieve the purpose of controlling the pitch. The baffle is used to protect the encoder cord from dust.

Rotation action control modification of slag skimming machine

Install a rope encoder on the arm of the slag scraper. Different rotation angles of the arm will result in different rope displacements. The PLC calculates the rotation angle of the slag scraper through distance conversion to achieve precise control.

Overall lifting action control of the slag skimming machine

A rope encoder is installed on one side of the oil cylinder that lifts the entire slag scraper. When the oil cylinder is running, the rope encoder will have a corresponding displacement to measure the lifting height of the oil cylinder.

Intelligent evaluation of slag raking

According to the established rules (such as the remaining slag area, etc.), the slag raking results are intelligently evaluated and graded.

Intelligent decision-making

A high-precision camera collects real-time images of the molten iron surface, intelligently analyzes the distribution of iron slag, calculates the coordinates of the slag through a self-learning algorithm, and plans a reasonable path for raking the slag.

Remote scrapping

A video surveillance system is installed on the slag raking station platform to monitor the slag raking platform and slag raking status in real time. In the operation room, the operator can check the slag raking status through the video surveillance system and manually control the slag raking machine to carry out slag removal. The slag removal evaluation system evaluates the iron slag content in real time. When the process conditions are reached, it will alarm and prompt the operator to end the slag raking. This method realizes remote slag raking operation.

casting slag remove

The position of the surveillance camera can be installed on the beam above or on the side of the small house of the slag scraper so that the line of sight is as close as possible to the original manual slag scraper.

2. Monitoring of slag basin

A high-precision vision camera and dust-proof cooling shield are used to adapt to the high temperature and high metal dust environment in the slag removal area. The camera is installed above the side of the slag basin to monitor the accumulation of iron slag in the slag basin. If the set overflow alarm threshold is exceeded, the alarm will prompt the replacement of the slag basin.

3. Exception handling

Serial number


Failure type

Treatment measures


Network failure

Industrial computer and secondary network interruption

The system automatically switches to manual state

Record the status and cause of the fault point

After the network is restored, the control mode needs to be manually switched


Industrial computer and PLC network interruption


PLC and original system PLC network interruption


Sensor failure

Displacement sensor failure

The system automatically switches to manual state

Fault information alarm prompt

Manual inspection of sensors

Manual inspection of communication lines


Radar ranging failure


Machine vision failure


Limit switch failure


Angle sensor failure


Mechanical failure

Tipping truck mechanical failure

System stops running

Run time monitoring alarm

Fault information alarm prompt

Manual inspection and maintenance


Slag scraper telescopic failure


Slag scraper rotation failure


Pitching failure of slag scraper


Hydraulic failure

The system is not stressed

Check motor operation\check oil pump


Uncontrolled speed

Check proportional valve\Check proportional valve controller


High hydraulic oil temperature

Check cooling pump


Motor does not run

Check motor protector

4. Intelligent diagnosis

The intelligent operation and maintenance system can intelligently diagnose equipment. When an abnormality occurs, it can remotely analyze and view status data of all equipment and software, analyze faults in real time, and quickly solve on-site problems to save maintenance time.

5. Technical indicators

Warranty terms

Number of packages of hot metal cans

Guarantee value

The success rate of slag raking

50 pack


Steel slag area identification up and down offset

50 pack


Average slag raking time

50 pack


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