This article simply compares and analyzes the unique advantages of scrap steel as a renewable resource in the iron and steel industry, and compares and analyzes in detail two types of scrap steel loading and unloading equipment commonly used in scrap steel loading and unloading operations, namely the working efficiency, benefit, and efficiency of the electric hydraulic grab and electromagnetic chuck. The advantages and disadvantages, etc., provide a certain reference for steel plants and scrap handling units to select scrap handling equipment suitable for on-site operation requirements.
Scrap is the recyclable steel that is scrapped and eliminated in production and life due to its service life or technological update. From the perspective of usage, scrap steel is mainly used as the main material for steelmaking in short-process electric furnaces or steel-making in long-process converters. Adding materials.
Extensive use of scrap steel resources can effectively reduce resource and energy consumption, especially in today's increasingly scarce primary mineral resources, the status of scrap steel resources in the sustainable development strategy of the world's steel industry has become more prominent.
At present, countries all over the world are actively and effectively recycling scrap steel resources to reduce dependence on mineral resources and long-term transitional consumption of energy.
With the development needs of the scrap steel industry, scrap handling has gradually changed from manual methods to mechanized and automated operations, and various types of scrap handling equipment have been developed.
1. Scrap steel handling equipment and working conditions
Most of the scrap produced in production and life cannot be directly used as furnace charge into the furnace for steelmaking, which requires a variety of scrap steel processing equipment to process scrap raw materials. Operation efficiency directly affects the efficiency of scrap steel processing and production.
The equipment mainly includes electro-hydraulic grabs and electromagnetic chucks, which can be used with various lifting equipment to meet the requirements of different working conditions. It has the characteristics of wide application, good applicability, and convenient disassembly and replacement.
2. Comparison of technical parameters and comprehensive benefits of hydraulic grab and electromagnetic chuck
Below, under the same working conditions, the performance parameters and comprehensive benefits of these two different equipment are compared.
1. Working conditions
Steelmaking equipment: 100 tons electric furnace.
Feeding method: feed in two times, 70 tons for the first time and 40 tons for the second time. The main raw material is structural steel scrap.
Material handling equipment: a 20-ton crane with a 2.4-meter diameter electromagnetic suction cup or a 3.2-cubic-meter hydraulic grab, with a lifting height of 10 meters.
Types of scrap steel: structural scrap, with a bulk density of 1 to 2.5 tons/m3.
Crane power: 75 kW+2×22 kW+5.5 kW, an average working cycle is calculated in 2 minutes, and the power consumption is 2 kW·h.
1. The main performance parameters of the two devices
The main performance parameters of these two devices are shown in Table 1 and Table 2 respectively. According to the relevant data in the table and the survey of some users, the following characteristics can be found:
∅2400mm Performance parameters of electromagnetic chuck
∅2400mm Performance parameters of electromagnetic chuck
|
Model |
Power consumption |
Current |
Dead weight |
dimension/mm |
suction/kg |
Average weight drawn each time |
|||
|
kW |
A |
kg |
diameter |
height |
Cut pieces |
Steel ball |
Steel ingot |
kg |
|
|
MW5-240L/1-2 |
25.3/33.9 |
115/154 |
9000/9800 |
2400 |
2020 |
2250 |
2600 |
4800 |
1800 |
3.2m3 electro-hydraulic grab performance parameters
|
Model |
Motor power |
Open time |
Close time |
Dead weight |
dimension/mm |
Grip force (suitable for various materials) |
Average lift weight |
|
|
kW |
s |
s |
kg |
Closed diameter |
Open height |
kg |
kg |
|
|
AMG-D-12.5-3.2型 |
30 |
8 |
13 |
5020 |
2344 |
2386 |
11000 |
7000 |
3.2m3 electro-hydraulic grab performance parameters
(1) For special working conditions such as scrap stainless steel and other scrap non-ferrous metals, the application of electromagnetic chucks has certain limitations.For example, scrap aluminum with scraps.
Comparison of performance and comprehensive benefits of 20t crane with hydraulic grab and electromagnetic chuck
|
|
electromagnetic chuck MW5-240L/1-2 |
hydraulic grab AMG-D-12.5-3.2 |
|
Electricity consumption for lifting a ton of scrap steel (KWh) |
0.67 |
0.14 |
|
Continuous operation hour capacity (t) |
120 |
300 |
|
Electricity consumption of one million tons of scrap steel spreader (KWh) |
6.7×105 |
1.4×105 |
|
Hours of lifting one million tons of scrap steel (h) |
8.333 |
3.333 |
|
Energy consumption of one million tons of scrap steel crane (KWh) |
1.11×106 |
4.3×105 |
|
Total power consumption for lifting one million tons of steel scrap (KWh) |
1.7×106 |
5.7×105 |
Comparison of advantages and disadvantages of electro-hydraulic grab electromagnetic chuck
|
|
Electromagnetic chuck |
Hydraulic grab |
|
safety |
When the power is cut off, accidents such as material leakage will occur, and safe operation cannot be guaranteed |
It has its own proprietary technology to keep the gripping force constant at the moment of power failure, safe and reliable |
|
Adaptability |
From regular steel scrap, high-density steel scrap to irregular crushed steel scrap, the absorption effect is diminishing |
All kinds of scrap steel, scrap non-ferrous metals, regular and irregular steel scraps, regardless of density can be grabbed |
|
One-time investment |
Electromagnetic chuck and electronic control system are put into use |
The hydraulic grab and the electronic control system are put into use |
|
Maintainability |
The electromagnetic chuck is overhauled once a year, and the electronic control system is overhauled at the same time |
The hydraulic grab is inspected once a month and once every two years. Why is the total cost equivalent? |
|
Service life |
The service life is about 4~6 years |
The service life is about 10-12 years |
|
Site cleaning effect |
Can be cleaned up |
Can't clean up |
2. concluding remarks
From the above comparative analysis, it can be seen that in the working conditions with large amount of scrap steel and high efficiency requirements, the electro-hydraulic grab equipment has obvious cost-effective advantages; while the working conditions are complicated, the efficiency requirements are not high, and the amount of scrap steel is small. In occasions, the electromagnetic chuck has better applicability.
In addition, for units with large scrap steel loading and unloading, in order to solve the contradiction between work efficiency and site cleaning effect, by adding two sets of electronic control systems to the lifting equipment, the exchange of electro-hydraulic grab and electromagnetic chuck can be realized. Grab is the main loading and unloading equipment, equipped with a small amount of electromagnetic chucks to clean up the site. The total investment cost is lower than the cost of all electromagnetic chucks, and higher than the cost of only using electro-hydraulic grabs, but on the whole, it is the best selection consider.
Post time: Jul-16-2021
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