A list of the contents of this article:
- 1 、What problems should be paid attention to in the process of pulling and closing of drop fuses?
- 2 、What checks should be made before pulling up the drop switch of the distribution transformer?
- 3 、Structure, principle and application of high voltage drop fuse
- 4 、What do you know about special containers?
- 5 、The difference between automatic drop packing machine and grab packing machine
- 6 、Five packaging principles and storage methods?
What problems should be paid attention to in the process of pulling and closing of drop fuses?
The main results are as follows: (1) in order to prevent accidents, load operation should be avoided during pulling and closing operation. Therefore, when pulling the switch, first pull the low-voltage side shunt switch, then pull the low-voltage master switch, and finally open the drop fuse (or oil switch) when the transformer is empty.
. When closing, the operation step is opposite to the above, that is, first close the drop fuse, then close the main switch on the low-voltage side, and then close the shunt switch according to the need.
(2) in order to prevent the wind action and cause the interphase arc short circuit, when opening the outdoor high voltage drop fuse, we should first pull the middle phase, then the wind phase, and finally the upwind phase; when closing, we should first close the upwind phase, then close the leeward phase, and finally close the middle phase. In the specific operation, you must use qualified insulated operating rods, wear insulated shoes, or stand on a dry wooden platform, and be supervised by personnel who are familiar with safety procedures.
The drop fuse is installed on the branch line of the 10kV distribution line, which can reduce the range of power outage, because it has an obvious break point and has the function of isolation switch, which creates a safe working environment for the line and equipment of the maintenance section and increases the sense of security of the maintenance personnel. Installed on the distribution transformer, it can be used as the main protection of the distribution transformer, so it has been widely used in 10kV distribution lines and distribution transformers.
Outdoor model
Outdoor drop fuses are suitable for overload and short circuit protection of transmission and distribution lines and power transformers and for dividing and matching rated load current in AC 50HZ and rated voltage 10KV power systems.
The widely used outdoor drop fuses are RW7 and RW11.
What checks should be made before pulling up the drop switch of the distribution transformer?
When pulling open the drop fuse, the operator must use a suitable voltage grade, qualified insulation rod, wear insulation shoes, insulation gloves, insulation cap and goggles or stand on a dry wooden platform, and be guarded to ensure personal safety.
The operator shall not have an impact at the beginning or end of the pull-and-close drop fuse. The impact will damage the fuse, such as breaking the insulator, crashing, duckbill deviation, pulling off the operating ring, breaking and so on. Staff in the fall fuse separation, closing operation, do not force too hard, impact, so as not to damage the fuse, and the separation and closing must be in place.
The process of closing the fuse is slow (start)-fast (when the moving contact is close to the static contact)-slow (when the moving contact is near the end of closing). The process of pulling the fuse is slow (start)-fast (when the moving contact is close to the static contact)-slow (when the moving contact is near the end of the pull). Fast is to prevent electrical short circuit and burn contacts caused by electric arc, slow is to prevent the impact of operation and cause mechanical damage to fuses.
Structure, principle and application of high voltage drop fuse
Drop fuse is a kind of short circuit protection switch most commonly used in 10kV distribution line branch lines and distribution transformers. It has the characteristics of economy, convenient operation and strong adaptability to outdoor environment. It is widely used in 10kV distribution lines and the primary side of distribution transformer as protection and equipment switching operation.
The principle and use of Tianheng high voltage drop fuse: the moving contacts at both ends of the fuse tube are fastened by fuse (melt). After pushing the upward contact into the protruding part of the “duck beak”, the upper static contact made of phosphorus and copper sheet is pressed against the upper moving contact, so the fuse tube is firmly stuck in the “duck beak”. When the short-circuit current fuses through the fuse, an arc is produced. Under the action of the arc, the steel paper tube lined with the fuse tube produces a large amount of gas because the upper end of the fuse tube is sealed, and the gas is ejected to the lower end to blow out the arc. Due to the fuse fuse, the up and down contacts of the fuse tube lose the fastening force of the fuse. Under the action of the gravity of the fuse tube and the spring of the upper and lower static contacts, the fuse tube falls rapidly, so that the circuit is broken and the fault line or fault equipment is cut off. The fuses in the real 10kV line system and on the distribution transformer can not operate correctly, one of the reasons is that the electrician’s quality is poor, the sense of responsibility is not strong, and the maintenance and repair of the drop fuse is not carried out all the year round; the second reason is that the product quality of the drop fuse is poor and can not pull and close flexibly. The function of the drop fuse is reduced for two reasons. In reality, there is often a lack of melting pipe, lack of melt or using copper wire, aluminum wire or even iron wire instead of melt. The trip rate of the line and the failure rate of the distribution transformer remain high.
What do you know about special containers?
Special containers “do not follow the international standards of containers, and their sizes and shapes are determined according to their use, such as some equipment boxes, engineering boxes, oil platform boxes, fire boxes, room boxes, advertising boxes, military boxes, etc., it can be said that special containers come in all shapes and sizes. Huizhou Juhui Container Technology Co., Ltd. is located in McCote Science and Technology Industrial Park, Weilong Management District, Liangjing Town, Huiyang District, Huizhou City, adjacent to Chaozhou Expressway, Huida Expressway and Huizhou Avenue. The company covers an area of 50000 square meters, including more than 10000 square meters of production workshop and more than 1200 square meters of office buildings. The company has several senior engineers and technicians who have been engaged in container design and production for many years, as well as a large number of technical workers who have been specialized in container production for many years, and have a complete set of container production lines. professional container production machinery and tooling equipment.
With a strong sales and service team, the company has won wide praise from customers for its product quality and after-sales service. The company adheres to the concept of perfect products and perfect service to provide customers with overall solutions. The company’s business scope: design and manufacture of all kinds of standards, non-standard containers, mechanical and electrical equipment containers, logistics containers, housing containers, modular computer rooms, modular container buildings, integrated data center containers, mobile container laboratories, energy storage photovoltaic containers, light steel structure, tanks, container parts processing, sales, and special container engineering projects. Yadong Weiye Container Co., Ltd. specializes in producing all kinds of special containers, special equipment boxes, photovoltaic inverter boxes, container module rooms, flying wing containers, SVG reactive power compensation containers, introducing foreign advanced production and testing equipment to provide qualified products for the majority of users.
The difference between automatic drop packing machine and grab packing machine
Drop type means that after accumulating a good quantity, open the load-bearing board and drop it into the carton to complete the packing; grasping is to lift the specified number of products through the grip or sucker, properly separate the interval between the products, and then put them into the carton. Are you looking for packing equipment?
Five packaging principles and storage methods?
Shockproof packaging, also known as cushioning packaging, plays an important role in various packaging methods. From production to use, the product has to go through a series of transportation, storage, stacking and loading and unloading process, placed in a certain environment. It will act forcefully on the product in any environment and cause mechanical damage to the product. In order to prevent the damage of the product, it is necessary to try to reduce the influence of external force. The so-called shockproof packaging refers to the packaging which takes certain protective measures to slow down the shock and vibration of the contents and protect them from damage. There are three main methods of shockproof packaging:
The main contents are as follows: (1) Comprehensive shockproof packaging method. The comprehensive shockproof packaging method refers to the shockproof packaging method in which the inner contents and outer packaging are all filled with shockproof materials.
(2) partial shockproof packaging methods. For products with good integrity and products with built-in containers, shock-proof materials can only be used in the corners or parts of the products or inner packaging. The main packaging materials used are foam shock cushion, inflatable plastic film shock pad and rubber spring.
(3) suspension shockproof packaging method. For some valuable and fragile items, in order to effectively ensure that they will not be damaged in the process of circulation, the outer packaging container is relatively strong, and then the contents will be suspended in the packaging container with ropes, belts, springs, etc., in logistics, no matter what the operation is. The contents are stably suspended without colliding with the packaging container, thus reducing damage.
2. Anti-damage protection technology
Cushioning packaging has strong anti-damage ability, so it is an effective kind of anti-damage packaging technology. In addition, the following anti-damage protection techniques can be adopted:
(1) binding and fastening technology. The function of bundling and tightening technology is to make groceries and bulk goods form a solid whole, so as to increase integrity, facilitate handling and prevent bulk piles to reduce damage.
(2) Container technology. The use of containers to reduce contact with the goods, so as to prevent damage.
(3) choose high strength protective materials. Through the high strength of the outer packaging material to prevent the inner contents from being damaged by external forces.
3. Anti-rust packaging technology
(1) antirust oil anti-rust packaging technology. Atmospheric corrosion is the result of electrochemical action of oxygen, water vapor and other harmful gases in the air on the metal surface. If the metal surface is isolated from various factors that cause atmospheric corrosion (that is, the metal surface is protected), the purpose of preventing metal atmospheric corrosion can be achieved. Antirust oil packaging technology is based on this principle of metal coating to prevent corrosion.
Packaging metal products with antirust oil requires that the oil layer should have a certain thickness, the continuity of the oil layer is good, and the coating is complete. Different types of antirust oils should be coated with different methods.
(2) Vapor antirust packaging technology. Gas phase antirust packaging technology is the technology of using gas phase corrosion inhibitor (volatile corrosion inhibitor) to prevent rust of metal products in sealed packaging containers. Vapor phase corrosion inhibitor is a kind of substance that can slow down or completely stop the destruction process of metal in erosive medium, it is volatile at room temperature, it is in sealed packaging container, the corrosion inhibition gas volatilized or sublimated in a very short time can fill every corner and gap in the whole packaging container, and adsorb on the surface of metal products at the same time, so as to inhibit the atmospheric corrosion of metal.
4. Anti-mildew and rot packaging technology
When the goods of food and other organic carbohydrates are shipped in the transport package, mold may grow on the surface of the goods. if it is wet in the process of circulation, the mold grows and propagates very fast, and even extends to the interior of the goods, causing it to rot, mildew and deteriorate, so special protective measures should be taken.
The measures to prevent mildew and deterioration of packaging are usually frozen packaging, vacuum packaging or high temperature sterilization. The principle of frozen packaging is to slow down the process of bacterial activity and chemical changes in order to prolong the storage life, but can not completely eliminate the deterioration of food; high temperature sterilization can eliminate the microorganisms that cause food decay, and can be treated with high temperature to prevent mildew in the packaging process. Some dried food packaging, should prevent water vapor immersion to prevent mildew and rot, you can choose waterproof steam and airtight packaging materials, vacuum and inflatable packaging.
Vacuum packaging is also known as vacuum packaging or exhaust packaging. This kind of packaging can not only prevent outside water vapor from entering the packaging container, but also prevent moist air inside the airtight moistureproof package and dew when the temperature drops. Using vacuum packaging method, we should pay attention to avoid excessive vacuum. To prevent damage to the packaging material.
To prevent mildew of the goods in the transport package, anti-mildew agents can also be used. There are many kinds of anti-mildew agents, and non-toxic anti-mildew agents must be selected for food.
For large closed boxes of mechanical and electrical products, ventilation holes or ventilation windows and other corresponding anti-mildew measures can be set up as appropriate.
5. Insect-proof packaging technology
Insect-resistant packaging technology, commonly used is insect repellent, that is, put a certain degree of toxicity and smell of drugs in the packaging, the use of volatile gas in the packaging to kill and dispel all kinds of pests. Commonly used insect repellents are tea, p-benzene dichloride, camphor essence and so on. Vacuum packaging, inflatable packaging and deoxidizing packaging can also be used to make pests have no living environment, so as to prevent insect pests.
6. Packaging technology of dangerous goods
There are thousands of dangerous goods, which are divided into ten categories according to their dangerous nature, that is, explosives, oxidants, compressed and liquefied gases, spontaneous combustion, water-burning articles, flammable liquids, flammable solids, poisons, corrosive goods, radioactive materials, and so on. Some articles have more than two dangerous properties at the same time.
The packaging of toxic goods should be clearly marked with toxic signs. The main measure of anti-virus is tight packing, non-leakage and airtight. For example, potassium dichromate (potassium bauxite) and sodium dichromate (sodium dichromate) are red with transparent crystallization and toxic, so they should be packed with strong buckets, the mouth of the barrel should be tight and the thickness of the iron plate should not be less than 1.2 mm. For commodities such as organic pesticides, they should be packed in asphalt sacks with tight seams. If it is packed in plastic or asphalt paper bags, it should be packed in gunny or cloth bags. Zinc phosphide, which is used as a rodenticide, is highly toxic. It is sealed in a plastic bag and then packed in a human wooden case, which is lined with two layers of Kraft paper, moisture-proof paper or plastic film to isolate it from the outside world.
For corrosive goods, we should pay attention to chemical changes in the materials of commodities and packaging containers. Metal packaging containers should be coated with paint on the container walls to prevent corrosive goods from corroding the containers. For example, the inner wall of the iron drum for packing synthetic fatty acids should be coated with an acid-resistant protective layer to prevent the iron barrel from being corroded by the commodity, thus the commodity will deteriorate. As another example, hydrofluoric acid is an inorganic acid corrosive product, which is highly toxic and can corrode glass, so it can not be packed in a glass bottle. It should be packed in a metal bucket or plastic bucket, but then in a wooden case. Formic acid is volatile and its gas is corrosive. it should be packed in a good acid-resistant jar, glass bottle or plastic bucket, tightly sealed, and then packed in a strong wooden box or metal bucket.
For the packaging of yellow phosphorus and other spontaneous combustion commodities, it is appropriate to put it into an iron barrel with a wall thickness of not less than 1 mm. The inner wall of the bucket shall be coated with acid-resistant protective layer, the bucket is filled with water, and the surface of the product is immersed. The mouth of the barrel is tightly closed, and the net weight of each barrel is not more than 50 kg. Another example is through the water bow [burning articles such as calcium carbide, which decompose in contact with water and produce flammable acetylene, which is packed in a strong iron drum and filled with nitrogen. If the barrel is not filled with nitrogen, a deflating piston should be installed.
For flammable and explosive goods, such as those with strong oxidizability, there are trace impurities or heated products that rapidly decompose and cause explosion. The effective method of explosion-proof packaging is to use plastic buckets for packaging, and then put the plastic buckets into iron buckets or wooden cases, each with a net weight of not more than 50 kg, and there should be a safety valve for automatic deflation, which can be deflated automatically when the barrel reaches a certain gas pressure.
7. Special packaging technology
(1) inflatable packaging Inflatable packaging is a packaging technology in which inactive gases such as carbon dioxide or nitrogen are used to replace the air in the packaging container, so it is also called gas replacement packaging. According to the characteristics of aerobic metabolism of aerobic microorganisms, this packaging method changes the composition of gases in sealed packaging containers, reduces the concentration of oxygen, and inhibits the physiological activities of microorganisms, the activity of enzymes and the respiratory intensity of fresh goods, so as to achieve the purpose of anti-mildew, anti-corrosion and preservation.
(2) vacuum packing. Vacuum packaging is a packaging method in which items are put into an airtight container and vacuumed before the container is sealed, so that there is basically no air in the sealed container.
General meat commodities, grain processing commodities and some commodities that are prone to oxidation can be packaged in vacuum. Vacuum packaging can not only avoid or reduce fat oxidation, but also inhibit the growth of some molds and bacteria. At the same time, when it is heated and sterilized, the heat transfer is accelerated because the gas in the container has been removed. The utility model not only improves the sterilization efficiency at high temperature, but also avoids the rupture of the packaging container due to the expansion of gas during heating sterilization.
(3) shrink packing. Shrink packaging is a packaging technology in which the goods (or inner packages) are wrapped with shrink film, and then the film is properly heated so that the film shrinks and clings to the goods (or inner packages).
The shrinking film is a kind of polyethylene film treated by special stretching and cooling, because the film produces residual shrinkage stress during directional tension, which will be eliminated after receiving a certain amount of heat, so that it shrinks sharply both horizontally and longitudinally. at the same time, the thickness of the film is increased, the shrinkage rate is usually 30-70%, and the shrinkage force reaches the maximum in the cooling stage and can be maintained for a long time.
(4) stretch packaging. Stretch packaging is a new packaging technology adopted since 1970s, which is developed from shrink packaging. Stretch packaging relies on mechanical devices to stretch and tightly wrap the elastic film around the package at room temperature. and a packaging method of sealing at the end. Since stretch packaging does not require heating, the energy consumption is only 1/20 of that of shrink packaging. Stretch packaging can be used for bundling individual items or for collective packaging such as pallet packaging.
(5) deoxidizing packaging. Deoxidizing packaging is a new deoxidizing packaging method after vacuum packaging and inflatable packaging. Deoxidization packaging is to use the deoxidizer which can react with oxygen in the sealed packaging container, so as to remove the oxygen in the packaging container, so as to protect the contents. The deoxidization packaging method is suitable for some items that are particularly sensitive to oxygen, and can be used in food packaging where even a small amount of oxygen will cause the quality to deteriorate.
8. Honeycomb packaging technology
(1) Honeycomb paperboard
Honeycomb cardboard has the advantages of large load-bearing capacity, good buffering, not easy to deform, high strength, environmental protection, low cost and so on. It can be prefabricated into various shapes instead of foamed plastic, and is suitable for the packaging of fragile products used in large quantities, especially for large or bulky fragile products.
(2) Honeycomb carton
Honeycomb carton is a box-shaped container made of honeycomb cardboard. Honeycomb paperboard has the advantages of light weight, compression, bending and shear strength, and has good cushioning and vibration isolation performance.
Classification: there are three kinds of packing boxes with honeycomb cardboard as the main material. One is the composite packing box. The outer layer of the box is made of fibreboard or plywood with strong piercing ability, the middle layer is made of honeycomb paper core, and the inner wall is bonded with straw cardboard; second, the whole honeycomb cardboard packing box. That is, honeycomb paper as the core, internal and external cardboard bonded; third, the inner-lined packing box, with corrugated cardboard as the box body, the upper and lower walls of the box are lined with honeycomb cardboard, which has strong shock resistance, pressure resistance, heat preservation and anti-puncture ability.
Advantages: compared with traditional corrugated cartons, honeycomb cartons have better mechanical properties, such as destructive drop, heavy palletizing, actual rolling and other experiments. the breakage rate of fragile items in honeycomb cardboard boxes is 50% lower than that in corrugated cartons. 600 kg weights placed on empty boxes will not deform for three months, and there is no need for polystyrene liner. The weight ratio of 2:5 to the corrugated carton of the same specification can save 60% of the cardboard. The popularization and application of this kind of carton will play a positive role in reducing the damage rate of goods in circulation and improving the quality of packaging products. Especially for high-value jade carvings, handicrafts and so on, honeycomb cartons are the best choice.
Disadvantages: however, due to the complex manufacturing process of honeycomb cardboard, especially the automatic box-making can not be realized at present, it is limited in application, which is mainly used in the packaging of fragile products with small batch, large volume and weight.
This is the end of the introduction on how to prevent bottle jumping in drop packing and drop packing machines. I wonder if you have found the information you need? If you want to know more about this, remember to collect and follow this site.