Before reading this article, please click on the blue font " China Chemical Safety Association " under the heading of this article and then click " Follow ", so you can receive the article for free. Share every day, completely free subscription, please rest assured! On the evening of the 27th, the New Taipei City Baise Water Park had a dust explosion accident in the last 5 minutes of the party event. The New North City Health Bureau announced the list of 516 injured in Baxian Paradise at 10 am on the 28th, and received treatment in 39 hospitals, including 194 serious injuries. people. Because of wearing a swimsuit, many of the injured were burnt in large areas. It was confirmed that there were 4 mainland tourists and 1 mainland female graduate student studying in Taiwan. It is understood that the "color party" held by the incident park, known as the largest color party in Asia, is not the first time to hold, this time attracted 12,000 people to participate. According to the people on the spot, when the evening activities gradually came to an end, the last color of the colorful powder was sprayed from the left side, the right side and the front side of the stage. After the powder was launched, a large piece of fire was blasted in front of the stage, and then the blazing flames swept over the sky, quickly swept the people wearing cool swimwear in front of the stage. Why do these colored powders cause an explosion? What is the “dust explosion†mentioned in the news? [1, what is a dust explosion] The dust is in the explosion limit range, encountering the heat source (open flame or high temperature), the flame instantaneously propagates through the entire mixed dust space, the chemical reaction speed is extremely fast, and at the same time, a large amount of heat is released to form high temperature and high pressure. Because of the constant pressure in this process, shock waves are generated, so the explosion will cause great destructive power. [2, which dust is explosive] Any solid substance in the form of fine powder is called dust. Dust that can burn and explode is called combustible dust. The dust of the seven substances is explosive: Metal, such as magnesium powder, aluminum powder, etc.; coal; Food, such as wheat and starch; Feed, such as blood meal, fish meal; Agricultural and sideline products such as cotton and tobacco; Forest products, such as paper powder and wood flour; Synthetic materials such as plastics and dyes. [3. Conditions of dust explosion] (1) flammable dust is suspended in air at an appropriate concentration to form a dust cloud; (2) There is sufficient air and oxidant; (3) There is a source of fire or strong vibration and friction. It is generally believed that flammable dust has the potential to cause an accident as long as conditions (1) and (2) are met. [4, the process of dust explosion] (1) The suspended dust is rapidly retorted or vaporized by a heat source to generate a combustible gas; (2) combustible gas is mixed with air to burn; (3) The heat released by the dust combustion is transmitted to the nearby suspended or blown dust by heat conduction and flame radiation. The dust is heated and vaporized and then burned. As the cycle proceeds successively, the reaction rate is gradually increased, and an explosion is formed by intense combustion. [5, characteristics of dust explosion] (1) Multiple explosions are its greatest feature; (2) The minimum required ignition energy is higher, generally above tens of millijoules; (3) The pressure rises slowly, the higher pressure lasts for a long time, the energy released is large, and the destructive power is strong. [6, the danger of dust explosion] (1) It is highly destructive; (2) It is easy to produce a secondary explosion; (3) It can produce toxic gases. [7, how to prevent dust explosion] (1) reducing the concentration of dust in the air; (2) controlling the temperature; (3) Control fire source, where there is danger of dust explosion, use explosion-proof motor, explosion-proof electric lamp and explosion-proof switch; (4) Control humidity and oxygen content. In recent years, color running has become more and more popular among young runners. At present, the largest color running in China, The Color Run official website is introduced as follows: “Color runs in the United States, and the first running event was in March 2011. In promoting the concept of running healthy, happy and popular, The Color Run is known as “the most joyful 5km run on the planet.†The Color RunTM is the original color run, opening a new chapter in traditional running activities and continuing to be fast. grow. There are only two rules for participating in The Color Run: 1. Wearing white clothes to the starting point; 2. Passing the finish line with the most dazzling color. After crossing the finish line, the joy doesn't stop - waiting for the color runner is the highest color party on Earth before the end stage. At that time, everyone will throw the colored powder in the hand into the air and gather them into a beautiful rainbow in the air. Each color runner will also be as colorful as the palette. This happy and magical moment will be deeply imprinted on everyone's mind. in. Believe us, this will be the coolest destination party you have ever seen! †Regarding "color powder", the official website explains: The Color RunTM color powder is mainly composed of corn starch, 100% natural and harmless to humans. However, it can be seen from the accident that even natural corn starch still has a greater risk. For those who like color running, please pay attention to safety. Attached: The Five Regulations of the State Administration of Work Safety on Preventing Enterprise Dust Explosions and Interpretation of Articles In 2014, the State Administration of Work Safety issued the "Stipulations on the Five Preventions of Enterprise Dust Explosions" (General Administration Order No. 68), which applies to coal, aluminum powder, magnesium powder, zinc powder, titanium powder, zirconium powder, Explosive dusting workplaces for flour, starch, powdered sugar, milk powder, blood meal, fish bone meal, textile fiber powder, wood powder, paper powder, rubber plastic powder, tobacco, etc. Among them, the first is for the factory regulations, the second is for dust prevention, the third is for fire prevention, the fourth is for waterproofing, and the fifth is for the system. Article 1 must ensure that the workplace meets the requirements of the standard specifications, and it is strictly forbidden to set up in illegal multi-storey buildings, safely spaced non-standard factory buildings and residential areas. Interpretation of the article: 1. The workshop of dust explosion hazard operation site must meet the requirements of "Code for Fire Protection of Building Design" (GB50016-2006) and "Safety Regulations for Dust Explosion Protection" (GB15577-2007). The plant should be designed in a single layer with a lightweight structure on the roof. If the plant is designed in multiple layers, it should be frame structure, and ensure that the surrounding wall has a sufficient area of ​​venting to ensure that the strength of the partition between the floors can withstand the impact of the explosion, ensuring that there is an independent safety exit on the floor above the floor. 2. The workshop of the dust explosion hazard operation site shall be separated from other workshops or buildings (structures), and the fire safety distance shall comply with the relevant provisions of GB50016. 3. Due to the huge power of dust explosion and wide range of hazards, it is strictly forbidden to set up in the residential area. Article 2 The ventilation and dust removal system must be designed, installed, used and maintained according to the standard specifications. Each class shall be cleaned and cleaned according to the regulations. The operation shall be strictly prohibited during the period when the dust removal system is out of service and when the dust exceeds the standard, and the production shall be suspended. Interpretation of the article: 1. The ventilation and dust removal system can effectively reduce the dust concentration in the workplace and reduce the dust deposition on the job site. Enterprises must design dust removal systems in accordance with GB15577, GB50016, "Explosion Guides for Dust Collectors for Dust Explosion Hazardous Locations" (GB/T17919-2008) and "Design Code for Heating Ventilation and Air Conditioning" (GB50019-2003). , installation, use and maintenance. 2. Dust explosion hazard The dust removal system of the work site must be set independently according to the provisions of GB15577 according to the process shards (partitions). All dust-producing points should be equipped with dust hoods. Interconnections are not allowed between the pipe networks of each dust removal system to prevent chain explosion. 3. In order to ensure the safe and reliable operation of the dust collector, the enterprise must inspect the indicators (parameters) such as the pressure difference between the inlet and outlet of the dust removal system, the temperature of the inlet and outlet ports and the temperature of the ash hopper according to the provisions of GB/T17919. The dust concentration is tested in accordance with the "Dust Determination in Workplace Air - Part 1: Total Dust Concentration" (GBZ/T192.1-2007). 4. When it is found that there is dust deposition in the dust removal system pipeline and the dust collector box, it is necessary to find out the cause and timely clean up. Vacuum cleaning should be used to prevent dust from flying. If it is necessary to use the blowing method, the source of the cleaning gas should be nitrogen, carbon dioxide or other inert gas to prevent dust explosion during the cleaning process. 5. The dust deposited in the workplace is the main factor causing the chain explosion and the big explosion. The enterprise shall establish a regular cleaning dust system in accordance with the provisions of GB15577, and each class shall promptly and comprehensively clean up the operation site. When cleaning dust, measures should be taken to prevent the dust from rising twice. It is best to use negative pressure to clean it. It is strictly prohibited to use compressed air to purge. 6. When the dust removal system is out of service and the dust accumulation in the job site is serious (more than 1mm in the thickest stack), it is easy to cause dust explosion. Therefore, the work must be stopped immediately and the personnel removed from the job. Article 3 Explosion-proof electrical equipment must be used in accordance with the regulations. Measures such as lightning protection and anti-static should be implemented to ensure the grounding of equipment and facilities. It is strictly forbidden to use various types of open fire and illegal use of working tools in the workplace. Interpretation of the article: 1. Dust explosion hazard workplaces should be prohibited from all types of open flames and sparks. The use of explosion-proof electrical equipment is a reliable measure to prevent electrical sparks. Explosion-proof electrical equipment must be installed and used in accordance with the Code for Design of Electrical Installations for Explosive and Fire Hazardous Environments (GB50058-1992) and the Safety Regulations for Electrical Explosion of Hazardous Locations (AQ3009-2007). 2. The huge discharge current generated during lightning discharge is extremely destructive, and it is easy to induce dust explosion accidents. Dust explosion dangerous workshops (construction and construction) must be installed in accordance with the "Lightning Protection Design Code for Buildings" (GB50057-2010) and grounded reliably. 3. The transportation, discharge, mixing, stirring, filtration, solid pulverization, grinding, sieving, etc. of the powder will generate static electricity, which may cause the dust to burn or explode. Dust explosion hazard All metal equipment, equipment casings, metal pipes, brackets, components, components, etc. in the workplace shall be protected against static electricity in accordance with GB15577 and the General Guidelines for Anti-static Accidents (GB12158-2006). All metal pipe joints (such as flanges) should be bridged. 4. Collisions and friction between iron components can cause sparks. In the workplace where dust explosion is dangerous, it is forbidden to use iron working tools that are prone to collision sparks. Use explosion-proof tools during maintenance. Especially in the presence of metal powders such as aluminum, magnesium, titanium, zirconium, etc., effective measures should be taken to prevent friction and impact with stainless steel and sparks. Article 4 must be equipped with waterproof and moisture-proof facilities for the production, collection and storage of metal dust such as aluminum and magnesium. It is strictly forbidden to spontaneously ignite dust. Interpretation of the article: The wet flammable metal dusts listed in the Catalogue of Hazardous Chemicals include: lithium, sodium, potassium, calcium, barium, magnesium, magnesium alloys, aluminum, aluminum-magnesium, zinc, and the like. In the process of production, collection and storage of these metal dusts, measures to prevent self-ignition of powders must be taken in accordance with GB15577, and waterproof and moisture-proof facilities should be installed to prevent dust from spontaneously burning and causing dust explosions and fire accidents. Article 5 The safety operation procedures and labor protection system must be strictly implemented. It is strictly forbidden to wear unqualified staff and wear protective equipment such as dustproof and anti-static. Interpretation of the article: 1. The safety operation procedures mainly include the maintenance and maintenance of the dust removal system, the dust cleaning operation, the polishing and polishing operation, the inspection and maintenance work, and the hot work. 2. In accordance with the "Safe Production Law" and GB15577 regulations, the main responsible person and safety production management personnel of the workplace where there is a danger of dust explosion must have the corresponding dust explosion safety production knowledge and management capabilities. Enterprises must conduct safety production and dust explosion-proof education for all employees, popularize dust explosion-proof knowledge and safety regulations, so that employees can understand the danger degree and explosion-proof measures of the dust explosion dangerous places of the enterprise; employees of dust explosion dangerous positions should carry out special safety technology. And business training, and passed the exam, the party is allowed to go to work. 3. It is easy for field workers to inhale dust for a long time to cause pneumoconiosis or silicosis. Field workers must wear dust-proof labor insurance products to work as required. In order to prevent static electricity from rubbing between human skin and clothing, between clothes and clothes, dust explosion hazard workers in the workplace are prohibited from wearing chemical fiber-like tools that are prone to static electricity. They must comply with GB15577 and the Rules for the Selection of Personal Protective Equipment (GB/T11651- 2008) stipulates that wearing anti-static tooling. (Source: Health, Safety and Environmental Protection Assistant) [Editor: Chen Guofang] Good things not only need to be collected, but also don't forget to share friends!
The rolled aluminium plate can be divided into twe types : Aluminium Hot Rolled Plate and aluminium cold rolled plate . Rolling is classified according to the temperature of the metal rolled. If the temperature of the metal is above its recrystallizationtemperature, then the process is known as hot rolling. If the temperature of the metal is below its recrystallization temperature, the process is known as cold rolling.
Different of cold rolled plate and hot rolled plate:
1. The accuracy of cold rolled plate is higher, the thickness of cold rolled plate is not more than xxxxxx mm.
2. The thinner, the thinner and the thin rolling 0.001mm steel strip; Hot rolling is now the thinnest to reach 0.78 mm.
3. The surface quality is superior, cold rolled steel plates can even produce mirror surface; On the surface of hot rolled plate, there are iron oxide and other defects.
4. Cold rolling can adjust its mechanical properties according to user requirements, such as tensile strength and process performance such as stamping performance. Cold rolling and hot rolling are two different kinds of rolling steels. As the name implies, cold rolling is made in steel at room temperature. Hot rolled steel is rolled in high temperature.
Hot rolled palte
Product Type
Typical Alloys
Typical Temper
Specification (mm)
Thickness
Width
length
Hot Rolled plate
3XXX & 5XXX
F/112
12-260
1000-3800
2000-38000
2XXX & 6XXX&7XXX
F/112
12-260
1000-3800
2000-38000
Annealed Plate
3XXX & 5XXX
O/H111
3.0-12
1000-2600
2000-24000
O
12-260
1000-3800
2000-38000
2XXX & 6XXX&7XXX
O
3.0-12
1000-2600
2000-24000
O
12-260
1000-3800
2000-38000
Quenched plate
2XXX & 6XXX&7XXX
T4/T6
4.0-12
1000-2600
2000-24000
12-260
1000-3800
2000-38000
Stretching Plate
2XXX & 6XXX&7XXX
T351/T451/T651
4.0-12
1000-2600
2000-24000
12-260
1000-3800
2000-38000
Cold rolled plate
Aluminium Rolled Plate,Hot Rolled Thick Plate,Aluminium Hot Rolled Plate,Aluminium Thick Plate La Ya Aluminium products Co.,Ltd. , https://www.layametal.com
3003/5052/5083/5A06
2024/6061/7020/7075/7021
3003/5052/5754/5182/5083/5086/5A06
2024/6061/7020/7075
2024/6005A/6061/6082
/7020/7N01/7075/7050
2017/2024/6061/6082/7020
/7N01/7075/7050
T7X51
