Bulk transportation means that the unpackedGranular, powdery and liquid goods, using appropriate tools and equipment for transportation.The realization of bulk transportation requires equipment matching and work coordination in major links such as production, loading, transportation, unloading, storage and use.Some transportation tools should also have better sealing performance and larger load capacity.Bulk equipment shall be capable of continuous transportation and accurate measurement.In some technologically advanced countries, industrial television, telephone, computer and other monitoring and remote control systems are widely used in the process of loading, unloading, storage, processing and supply of freight yards, and the corresponding measuring equipment and process flow are also constantly improved.Bulk transportation is conducive to mechanized loading and unloading, accelerating the turnover of vehicles and ships;Save packaging materials, manpower and financial resources, and improveTransport efficiency；Reduce cargo loss and ensure transportation quality;Reduce environmental pollution, etc.Has becometransportationOne of the directions of technology development.[1]
Chinese name
Bulk transportation
Advantages
It is conducive to the implementation of mechanized loading and unloading to accelerate the turnover of vehicles and ships;Save packaging materials, manpower and financial resources, and improve transportation efficiency;Reduce cargo loss and ensure transportation quality;Reduce environmental pollution, etc
Development profile With the development of production, the packaging in the transportation process has also undergone corresponding changes.Granular and powdery goods have roughly gone through the process of barreled bagged bulk;Liquid cargo is transported from barrels (bottles) to bulk (see tanker transportation).Before the 1930s, wooden barrels and iron barrels were often used as containers for cement.Since the barrels are bulky, difficult to load and unload, large in size and high in cost, they will gradually be packed in bags in the future.Bagging is still not convenient for mechanized loading, unloading and handling, and will consume a large amount of high-quality wood for paper making.At the same time, packaging requires a lot of manpower and labor intensity.Since the 1950s, commercial concrete and concrete products have developed rapidly in some countries, cement users are concentrated, and the amount of cement is large, so bulk cement transportation has developed rapidly.The proportion of bulk cement transportation volume in the total cement transportation volume has reached 92% in the United States in the early 1970s;Japan reached 92% in 1974.Similarly, grain transportation has also experienced the development process from bagging to bulk.In wheat rich countries such as the United States, Canada, Australia, wheat storage and transportation, whether for export or domestic sales, are almost all in bulk.Others, such as sugar and fertilizer, are also common.In 1961, China began to pick up and unload ships carrying imported bulk grain at coastal ports;In 1964, Xinjiang Cement Plant began to test run bulk cement, which was gradually popularized later.
Implementation conditions
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The conditions for bulk transportation to realize bulk cargo transportation require equipment matching and work coordination in several major links, such as production, loading, transportation, unloading, storage and use.For granular and powdery goods, there are generally three kinds of loading equipment: mechanical, pneumatic and pneumatic loading equipment.The means of transport shall have good tightness and large load capacity. The vehicle shall also have light deadweight, low center of gravity and be easy to load and unload.Special vehicles and ships shall be universal within a certain range.Under appropriate conditions, containers (bags) can also be used for transportation.The unloading equipment used for special vehicles generally includes four types of unloading devices: gravity, mechanical, pneumatic and pneumatic;For special purpose ships, depending on the ship structure, the compressed air with higher pressure and the air with low pressure and large air volume shall be used respectively.The storage device is a repository.There are two types of bulk cement warehouses (or transit warehouses): permanent (applicable to perennial users) and mobile (applicable to mobile construction sites);Bulk grain storage warehouses are generally permanent or semi permanent, including vertical (round) silos, mechanized room type warehouses, etc., all of which are equipped with warehousing equipment and unloading equipment.
The equipment used in each link of bulk transportation shall be based on continuous transportation and accurate measurement.In some technologically advanced countries, industrial television, telephone, computer and other monitoring and remote control systems are widely used in the loading and unloading operations of freight yards, storage, processing and supply processes.The selection of measuring equipment shall consider the type, specification and load of the means of transport.Rail weighbridge is mostly used in railway transportation, ground weighbridge is mostly used in highway transportation, and electronic scale and measuring warehouse are mostly used in factories, warehouses, docks and ships for measurement.These are static metering equipment.In the 1960s, some countries such as the United States, the Federal Republic of Germany and Japan began to use dynamic metering equipment.This equipment is a kind of comprehensive technical equipment, basically composed of weighing platform and transducer（Load cell）And data processor.Sensor technology is the key to affect the measurement accuracy.Developed in China since 1965Dynamic track scale, already finalized products are used in some departments.
benefit
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Technical and economic effects Bulk transportation is beneficial to:
① Reduce working procedures, realize mechanization of loading and unloading, improve working conditionslabour productivity。
② Save packaging materials.If one ton of cement is packed, about 6 kilograms of wrapping paper is needed, and the production of these papers requires about 0.033 meters of red and white pine high-quality wood.A large amount of wood can be saved after bulk loading.Bulk grain can save a lot of packaging materials such as hemp and cotton than bagged grain.
③ Save expenses and reduce costs.For example, the packaging cost per ton of cement accounts for about 1/5 of the production cost of cement and 1/6 of the sales price.Saving packaging costs can significantly reduce production costs.
④ Reduce losses and ensure quality.For example, bagged cement generally goes through several operations from production to use, such as production loading transportation unloading storage use. The damage rate of paper bags is generally about 10%, sometimes up to 30%, and the cement loss is generally 2.5%~5.0%.Bulk cement is transported in sealed containers, and the loss can be reduced to 0.5%.At the same time, bagged cement is easy to change in quality during storage, especially high-grade cement. After six months of bagged storage, the strength of bagged cement decreases by about 20% on average, while bulk cement is not easy to damp and deteriorate due to sealed storage.In the case of bulk transportation of grain, the loss and pollution are also less under the condition of supporting equipment.
