The Complete Guide to Safety Management and Technology Sharing of Casting Workshop
The Complete Guide to Safety Management and Technology Sharing of Casting Workshop
Keywords: safety coefficient; Technology sharing; Development trend; Management
The safety of the casting workshop has always been an issue that the aluminum industry attaches great importance to.
The safety of the casting workshop must be the top priority of the work.
How to increase the safety coefficient of the casting workshop is also a matter of great concern to aluminum factories.
This article will introduce some methods for improving the safety coefficient of the casting workshop from staff management and equipment improvement.
1. Casting deep well explosion
The explosion of high-temperature molten aluminum is mainly a physical explosion,
That is, a large amount of liquid high-temperature metal encounters a large amount of water,
And the liquid solidifies and cools to release a large amount of heat, causing the water to become water vapor, and the high-temperature gas instantly expands thousands of times, causing an explosion.
Violent explosions can occur when molten aluminum and water are mixed under the right conditions due to a number of factors.
For example: At temperatures above 660°C, water in contact with molten metal evaporates into steam almost instantaneously.
The volume of the steam increases rapidly, throwing the molten metal a great distance, and this alone can cause serious injury and destruction.
This also breaks down the molten aluminum, known as fragmentation.
If there is a larger contact area between the water and the molten aluminum, this further increases the rate of heat transfer to the fluid and increases the rate of reaction between the steam and the aluminum.
Let’s first look at the physical explosion, which is easy to understand.
It can be imagined that if a group of liquid aluminum of 700-800℃ suddenly rushes into a group of water, the heat exchange process will occur rapidly, and the efficiency of heat conduction and heat convection is extremely high.
So that a large amount of water vapor is generated in a short time, if the place where the liquid aluminum and water both meet is still in a limited space, what do you think will happen?
That’s right, that is the sudden increase in internal pressure, the rapid expansion of water vapor volume, and an explosion.
Next, look at the chemical explosion.
The physical explosion is just the beginning because there will be a chemical reaction between the high-temperature aluminum liquid and water, as shown in the figure below:
It can be seen that hydrogen gas appeared in the product.
When it comes to this, many friends may know what will happen next.
After all, hydrogen explosions are too familiar.
From the perspective of conditions, once the volume concentration of hydrogen in the air reaches Between 4% and 75.6%,
It will explode immediately when it encounters a fire source.
We don’t need to say more about this power.
2. People management
2.1Reasonable management system
Establishing a reasonable safety management system is the most basic and indispensable thing for workshop safety management.
The workshop has a series of systems such as “Safe Production Management System”, “Equipment Safety Operation Regulations”, “Equipment and Infrastructure Management System”, “Hazardous Operation Safety Management System”, “Deformed Aluminum and Aluminum Alloy Process Operation Regulations” and so on for safe production management.
2.2 Clear staff job responsibilities
2.2.1 With clear personnel post responsibilities and a clear division of labor, everyone can perform their duties, do their own work well, give full play to their talents, and make the best use of everything.
There should never be a zone of “be nobody’s business”.
2.2.2 The workshop implements the “joint and several responsibility system” to mobilize all employees, participate in them, and work together for common progress and common safety.
2.3 Persistent management action
2.3.1 The monthly safety training time in the workshop must comply with the ” 533 Safety production rules and regulations ” requirements,
And the safety content training time should be at least 50% of the time, and it is often carried out by watching videos to increase employees’ intuitive awareness.
2.3.2 The manager watches the video monitoring for at least 15 minutes every day, and deal with problems in time if they find any problem.
2.3.3 Team leaders and workers submit a self-examination and self-correction hidden danger investigation report every day.
The workshop arranges special staff to sort out and summarize, and the manager personally designates the responsible person, stipulates the completion time, solves potential safety hazards, and improves the safety factor.
Potential safety hazards and violations must be dealt with quickly to kill bad behaviors in the cradle and not let them form a habit.
In order to encourage workers to actively discover potential safety hazards and report them, the company and the workshop will regularly reward the workers with good performance.
2.3.4 Every week, the workshop manager leads a team to conduct a thorough “safety 5S” special inspection activity on the whole workshop.
2.3.5 When resuming work after each major festivals, the manager must implement ” have a special meeting on production safety,
Make a comprehensive plan for resumption of work and production, hold a general meeting of employees, conduct a safety education for all employees, make a set of emergency response plans, and organize a plant-wide safety inspection”,
And employees must implement ” Listen to a safety production expert class, watch a safety production warning education film, and distribute a set of safety production brochures. ” to ensure safe operations.
2.3.6 Conduct targeted safety emergency exercise at least once a year
2.3.7 Have a meeting before and after work every day.
3. Equipment improvement
The explosion-proof technical setting for non-stop water supply in case of failure during casting;
In case of casting failure, non-stop water supply requires the setting of the casting machine and the setting of the casting cooling water pool.
3.1 Setting requirements for casting machines:
3.1.1 The water supply system must have an emergency water supply circuit.
3.1.2 The main waterway must be equipped with a backup water pump, and equipped with a water pressure gauge and a pressure alarm device.
3.1.3 In case of abnormality, it shall be possible to automatically switch from the main waterway to the emergency waterway for water supply through the electric control valve.
3.1.4 The emergency water source control valve can use both electric and manual valves.
3.2 Setting requirements for cooling water pool
3.2.1 The cooling water pool must be equipped with a high-level water pool, and the main water supply pump of the casting machine must draw water from the high-level water pool.
3.2.2 The capacity of the high-level water pool must be sufficient to provide sufficient emergency water supply in case of failure of the main water supply circuit for emergency casting safety stop.
3.2.3 The high-level water pool shall be equipped with an audible and visual alarm device for the lower limit of the water level and an automatic water replenishment device.
3.2.4 Bottom discharge valves and filtering devices shall be installed on the main water supply and emergency water pipelines to ensure that the pipelines are not blocked.
3.2.5 The cooling tower should be added above the high-level water pool to ensure the temperature of the cooling water.
3.3 Containment and non-expansion emergency prevention operations in case of accidents.
3.3.1 Remove the water accumulation in the production and ensure that the melting furnace and holding furnace themselves and their surroundings are dry.
3.3.2 Ensure that the furnace opening is locked before smelting to prevent aluminum leakage.
3.3.3 Auxiliary equipment and tools related to casting machines (especially those in contact with molten aluminum) should be kept dry.
3.3.4 Each casting machine shall be equipped with at least 5 emergency residual aluminum buckets.
3.3.5 During casting, if a large amount of molten aluminum leaks into the water and cannot be controlled,
It is necessary to block the furnace hole of the melting furnace (holding furnace) in time, and the operator should evacuate to a safe area immediately.
3.3.6 Guarantee the height of the high-level water pool, the casting can be started when it reaches the specified water level.
3.3.7 Guarantee the quality of cooling water to prevent pipeline blockage caused by poor water quality, resulting in water shortage in casting and leakage of molten aluminum.
3.3.8 Be sure to prepare emergency plans.
4. Discussion on upgrading from passive safety to active safety
4.1 By adding a laser level gauge on the launder and mold plate
The supply of molten aluminum is automatically controlled, and the dangers caused by the sudden gushing of molten aluminum and the interruption of flow are avoided during the casting process.
The flow control of molten aluminum in the traditional aluminum alloy casting process can only be controlled by artificially opening iron braze, which has the disadvantages of low control accuracy and poor safety factor.
4.2 The melting furnace (holding furnace) adopts automatic tilting back to cut off the flow
Completely eradicate difficult locking due to deformation of the water outlet
4.3 Casting system control components DC control and UPS power supply during failure period
All solenoid valves and alarm node voltages are DC24V;
When the power system fails, all valves and alarm power are powered by UPS;
When the hydraulic pump stops working, the continuous casting will not be affected at this time, and the platform will descend at the original speed;
When the power system and UPS fail at the same time, the emergency lowering valve on the hydraulic station can be manually opened to ensure that the platform is lowered.
4.4 There is a separate emergency pool
The capacity and height of the emergency pool must be sufficient to provide sufficient emergency water supply for emergency casting to stop safely in the event of failure of the main water supply circuit.
The main water outlet of the general emergency pool must be 2.5m higher than the casting plate.
If the emergency pool only supplies one casting well, and the effective water capacity shall not be less than 20m³.
If the emergency pool is supplied with more than two casting wells, and the effective water capacity is not less than 80m³.
When there are more than 3 casting wells, the supporting high-level water emergency pool should also be equipped with an audible and visual alarm device for the lower limit of the water level and an automatic water replenishment device.
When the water level is low, the cooling water should be able to automatically replenish water to ensure the water volume of the high-level water pool.
4.5 Coat a layer of high density and good elasticity coating on the wall of main and auxiliary casting well
It can prevent microorganisms in the well from accumulating and adhering to the casting well wall to ferment and produce harmful gases, greatly increase the surface toughness of the casting well wall, resist explosion impact and effectively reduce damage.
Summary: The safety and explosion protection of aluminum casting has changed from passive safety to active safety, which provides new ideas for equipment control, facility safety protection and standardized design.
Changing the traditional man-made management and control methods, and upgrading the active safety of equipment control can reduce the unstable factors caused by man-made operations, greatly improve the safety of aluminum casting, reduce the probability of accidents, and curb the expansion of accidents.
Technical recommendation
Aluminum slag recycling grab bucket
Well Cleaning magic weapon –Aluminum slag cleaning grab bucket
It is used to clean and recover the aluminum slag at the bottom of the aluminum billets casting well, without pumping water or manually going down the well to clean it.
Save labor and effectively protect the safety of staff.
The use of a single-rope grab bucket can completely replace the status of manual slag removal in deep wells (wire rope casting), and avoid safety accidents when people work in a limited space such as deep wells
Workers are killed or injured by falling objects;
Harmful gases lead to personnel poisoning or hypoxia, etc.
At the same time, it can greatly save manpower and material resources
It usually takes 5 workers at least 2 days to clear a deep well aluminum slag, now, with the casting well cleaning magic weapon, it only takes 2 workers and half a day to clear a deep well aluminum slag.
This is a safe and efficient device, and it is recommended for the casting workshop.
Casting liquid aluminum outlet gate locking device
Add a locking device to the upper cover of the flow launder opposite the aluminum liquid outlet of the fixed melting furnace, use the flow hole tapping bar to block the casting water outlet, and then turn the rotating handle clockwise until it stops, as long as the rotating handle is rotated in place.
It is ensured that the aluminum liquid will not wash away the flow hole tapping bar, so that the aluminum liquid will flow out and cause a safety accident.
5. Cost reduction and efficiency increase, environmental protection and energy saving are the main development directions of new aluminum casting technology
At present, the development status of casting technology is mainly the coexistence of multiple casting technologies, and the requirements of cost, quality and efficiency of products are as high as ever, while the requirements of environmental protection, energy saving and safety are gradually strengthening.
With the continuous emergence of new technologies, backward technologies are gradually eliminated.
With the demands of competition in the industry and the regulation and guidance of national policies, the technology of melting and casting technology has been continuously improved.
It not only pays more attention to reducing costs, improving product quality, and improving production efficiency, but also pays more attention to environmental protection, energy saving and safety requirements, and is closely related to information technology.
The combination of technology has become an inevitable trend, Cost reduction and efficiency increase, environmental protection and energy saving are the main development directions of new aluminum casting technology.
Not only casting well aluminum slag cleaning grab bucket, but also aluminum dross machine, the total solution and turnkey project for aluminum melting and casting workshops!
Contact us now to get a reliable No-obligation quote on your aluminum melting and casting project!
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February 22, 2023