Pneumatic conveying

Pneumatic conveying

Pneumatic conveying, also known as airflow conveying, is a transport technology that USES the energy of air to carry out continuous conveying of powdery and granular materials. In electric power, chemical industry, food processing, steel, metallurgy, machinery manufacturing, medicine and other industries have a wide range of applications.  According to the mass of the powder carried in the gas carrier per unit volume, it can be divided into dilute phase pneumatic conveying and concentrated phase pneumatic conveying, while concentrated phase pneumatic conveying is divided into concentrated phase dynamic pneumatic conveying and concentrated phase static pressure bolt-flow pneumatic conveying.  According to the transmission mode can be divided into: suction type, pressure type and mixed type. Pneumatic conveying system of powder materials can be divided into suction type, pressure type or two combined three.     

1- silencer; 2- induced fan; 3 - bin; 4- dust collector; 5- discharge gate valve; 6- steering valve; 7- feeding bin; 8- feeding valve; 9- railway hopper car; 10 to the cabin  The system is simple, with no dust flying in the sky, and can take materials from multiple points at the same time. The working pressure is low (less than 0.1mpa), but the conveying distance is short, and the gas-solid separator has strict sealing requirements.  The working pressure is large (0.1~ 0.7mpa), the conveying distance is long, the requirements for the separator's dense filling are slightly lower, but it is easy to mix with oil, water and other sundries, and the system is more complex.  Pressure feeding is divided into two types: low pressure conveying and high pressure conveying. The working pressure of the former is generally less than 0.1mpa. The feeding equipment includes air conveying chute, pneumatic lift pump and low pressure jet pump. The working pressure of the latter is 0.1~ 0.7mpa, and the feeding equipment includes warehouse pump, screw pump and jet pump.     

1- dust collector; 2- gas-solid separator; 3- feeder; 4- blower; 5 - feed hopper  Direct delivery of bulk materials, no packaging, high efficiency. Simple equipment, small floor space, low maintenance costs. Can achieve automatic remote control, low management costs. Flexible pipeline layout, so that the factory equipment configuration rationalization. In the conveying process, the materials can not be easily affected by damp, dirt and mixed with sundries, but also can reduce dust, improve environmental hygiene. The process of mixing, grading, drying, heating, cooling and separating of materials can be carried out simultaneously in the conveying process. It is convenient to realize concentrated, dispersed, large height (up to 90m), long distance (up to 2000m), and powder transportation suitable for various terrain.     

Power consumption is large, especially for short distance transmission. Compressed air system is required. It is not suitable for conveying materials with strong adhesion and particle size greater than 30mm.  Air transport chute is a dense phase fluidized transport equipment. It is composed of two fluted shells made of thin steel plate, with a breathable layer sandwiched between the two shells. The whole chute is arranged at a certain Angle. The material is added into the upper shell by the charging device, and the air is blown into the lower shell by the blower through the air permeability layer to fluidize the material. The inflatable material flows forward along the slope to achieve the purpose of transportation.  The equipment itself has no moving parts, so the probability of wear is greatly reduced, durable, simple equipment, easy maintenance and overhaul; Less investment, no noise in operation, less power consumption, safe and reliable operation; Easy to change the direction of conveying, suitable for multi-point feeding and multi-point unloading.  It is suitable for small particles or powdery non-cohesive materials. If there are too many coarse particles in the materials, they will accumulate in the tank during the conveying process. When they accumulate to a certain amount, they can only be operated after manual slag discharge. It is necessary to ensure that there is an accurate downward inclination arrangement, so the drop is larger when the distance is longer, which leads to the difficulty of civil construction.