Positive Pressure Conveying System

The positive pressure conveying system is composed of roots blowers, manual gate valves, rotary feeding devices, conveying pipelines, pipeline diverter valves, as well as storage bins, top - of - bin dust removal devices, electrical control systems and related auxiliary equipment.It adopts the pneumatic conveying method to transport materials. The conveying pipelines can be arranged according to the specific terrain, realizing centralized, decentralized, large - height and long - distance conveying. The conveying process is not affected by climatic conditions, which can ensure that materials are not damp, conducive to production and environmental protection, and has the characteristics of high efficiency, energy conservation and environmental protection.The positive pressure conveying system is widely used in the power, metallurgy, petrochemical, plastic, food, building materials and hydropower industries.

The positive pressure conveying system is a way of conveying materials by using positive pressure gas. It is also called the pressure - feeding conveying system. During pressure - feeding pneumatic conveying, gas is input into the feeder to mix air and materials. The mixed gas and materials pass through the separator, where the materials and gas are separated. The gas is discharged into the air after passing through the dust removal device, and the materials are deposited into the silo.The positive pressure conveying system has the characteristics of simple system, flexible layout, reliable operation, high degree of automation, low system investment, high ash - gas ratio in conveying, low flow rate, strong wear resistance, small maintenance workload and low annual operation cost.

Working principle of Positive Pressure Conveying System:

The positive pressure conveying equipment uses gas with a pressure lower than 0.1MPa (usually air or nitrogen) to blow materials to a designated position at a relatively high speed, and the gas - solid ratio is generally 1 to 10.The initial speed of the system is generally more than 12m/s, the terminal speed can be as high as 35m/s, the terminal pressure is basically close to the atmospheric pressure. The power is generally provided by roots blowers, and multi - point feeding and multi - point discharging can be realized through valve control.Sometimes it can also be used in combination with negative pressure vacuum conveying to meet special requirements.

The positive pressure conveying system usually uses roots blowers to provide air source. When the system works, the roots blowers are started to generate high - pressure columnar air flow. The high - pressure columnar air flow passes through the jet pump, and a negative pressure is generated inside, so that the materials supplied by the rotary feeder are timely sucked into the injection port of the ejector.The materials are transported to the storage bin through the conveying pipeline.Then, the top - of - bin dust remover installed on the top of the storage bin separates the materials from the conveying air flow, and the remaining air flow is discharged outdoors in a timely manner, which also avoids generating too much dust on the site.

Application fields of Air Conveying:

It is often suitable for long conveying pipeline distances and fine, granular, abrasive, non - abrasive and other difficult - to - convey materials, such as PVC powder, ternary materials, nano calcium carbonate, elastic rubber, flour, sugar alcohol, white sugar, milk powder, water - absorbing resin, lithium battery raw materials, etc. And a variety of process combinations can be realized in the middle, such as iron removal, filtration, drying, pressure maintenance, vacuum pumping, etc.

Composition of Pneumatic Conveying:

It is mainly composed of power source (fan), feeder, conveying pipe, material separator and dust remover.

• Power source: Blowers, compressors, exhaust fans or vacuum pumps, etc., which are used to generate air flow and provide energy for the entire conveying process.
• Feeder/loading machine: A kind of equipment that can mix materials with air and send them into the conveying pipe.The rationality of the feeder structure directly affects the conveying capacity, working stability and power consumption of the entire pneumatic device.
• Conveying pipe: Reasonable arrangement, selection of conveying pipe and structural size can avoid blockage of the pipeline system or reduce wear, reduce pressure loss, and have a great impact on the productivity, energy consumption and use reliability of the conveying device.
• Material separator: It can separate the conveyed materials from the air flow. The commonly used separators include centrifugal separators and volumetric separators.
• Dust remover: The gas coming out of the separator contains 5 to 40 microns of dust. The dust remover can remove the dust to prevent air pollution and fan wear.

Working process of Pressure Conveying:

• Feeding stage: The material sealing valve, airtight valve and exhaust valve are opened, and the other valves are closed. Materials fall into the bin pump under the action of gravity. When the time reaches the set value, the material sealing valve, airtight valve and exhaust valve are closed, and a feeding process is completed.
• The air inlet valve opens automatically, compressed air enters the bin pump, diffuses and passes through the fluidized bed. While the materials are fully fluidized, the air pressure in the bin pump will gradually increase.
• When the pressure of the transmitter reaches a certain value, the pressure transmitter sends a signal, the discharge valve opens automatically, the fluidization of materials on the fluidized bed is strengthened, and the conveying starts. When the materials in the bin pump gradually decrease, the pressure display gradually drops.During this process, the materials on the fluidized bed are always in a state of being fluidized while being conveyed.
• Purging stage: After the materials in the pump are conveyed, when the pressure drops to the empty pipeline resistance, the air inlet valve is closed. After a certain interval, the discharge valve is closed, the pressure boost lasts for 3 - 5 seconds to clean the pipeline, and the feed valve is opened. So far, a conveying cycle is completed.

Advantages of Pneumatic Transfer System:

• High working pressure and large conveying capacity.Therefore, long - distance and high - capacity conveying can be realized, and ultra - long - distance conveying can be realized by using a booster.
• Due to the low conveying speed of materials, there is less wear on the conveying pipeline and materials.
• High material - gas ratio, low air consumption and saving operation cost.
• It can convey from a single point to multiple points, or have multiple points for feeding and discharging, which is easy for process design.
• The system has high pressure and low air consumption.
• Small conveying air volume, and material - gas separation is easy to realize.
• High degree of automation. During the conveying process, the processes of metering and batching, screening, mixing, iron removal and impurity removal can be realized at the same time to meet your production needs.
• Conveying in a fully closed pipeline, environmentally friendly and pollution-free.
• Stable and reliable operation, no leakage and no dust emission.
• Modular design makes maintenance simpler and more convenient.

This series of products are highly customized according to the customers' requirements. Therefore, we are unable to provide the procedures and parameters at present. If you are interested in this series of products, please contact us immediately. Audop Company will assign experienced engineers to communicate with you as soon as possible.