pneumatic conveying system for powder

Pneumatic powder conveying system is a system that uses gas as the conveying medium to convey powder from one place to another through pipelines. ‌This kind of system can be divided into various types such as suction type, pressure feeding type and suction pressure mixing type based on material characteristics, process configuration and material requirements.
The main components of the powder pneumatic conveying system include powder collection tanks, filter systems and conveying pipelines. The powder collection tank is used to temporarily store inhaled powder materials, usually made of stainless steel, which is easy to clean and install; the filtration system is used to filter the air and dust in the powder collection tank to ensure the normal operation of the system; the conveying pipeline is for powder transportation The main channel‌.
According to different classification standards, powder pneumatic conveying systems can be divided into the following categories:
‌Medium and low pressure positive pressure pneumatic conveying system‌: Using Roots blower and centrifuge as the air source, it is suitable for short-distance, low-pressure transportation and has the characteristics of reliable transportation‌.
‌Low vacuum negative pressure pneumatic conveying system‌: Negative pressure is generated through a vacuum pump, which is suitable for long-distance and large-scale powder transportation. It has the advantages of reliable sealing and suitable for large-scale transportation.
‌Rotary valve high-pressure pneumatic conveying system‌: Uses high-pressure gas for continuous conveying, suitable for medium and long-distance transportation, and suitable for conveying easy-flowing particulate matter‌.
Powder pneumatic conveying systems are widely used, including fly ash in power plants, cement in cement plants, powder for metallurgy, etc.

Pneumatic conveyor working principle

‌‌The working principle of a pneumatic conveyor is to use the energy of air flow to transport granular materials in a closed pipe along the direction of the air flow. ‌This process is a specific application of fluidization technology, which uses pressurized air as the transport medium to transport materials from one place to another.
Basic Principle‌: Pneumatic conveyors use the energy of air flow to transport granular materials from one place to another through closed pipes. This conveying method can be carried out in horizontal, vertical or inclined directions, and during the conveying process, physical operations such as heating, cooling, drying and air flow classification of materials or certain chemical operations can be performed simultaneously.
‌System composition‌: Pneumatic conveying system usually consists of feeder, conveying pipeline, separator and ‌material warehouse. The feeder is responsible for feeding materials into the conveying pipeline, which is the main channel for material transmission. The separator is used to separate the transported gas and materials, and the material warehouse is the storage location of the materials.

Pneumatic conveyor diagram

Dense phase pneumatic conveying system

Dense phase pneumatic conveying technology realizes the transportation of bulk materials by forming a pressure difference along the pipeline and using air to move to areas with lower pressure. This process can be done with a vacuum inducer or by injecting compressed air into one end of the pipe or along the pipe. A small amount of air is used to move a large amount of closely connected block material through a conveyor line, much like an extrusion. Dilute phase conveying systems typically use large volumes of air to convey relatively small amounts of suspended material at high speeds, while dense phase conveying systems have the advantage of being able to efficiently move denser solid particles through the conveyor line at relatively low speeds.
type:
Dense Phase Pressure Conveying – This method is typically used to convey abrasive or friable materials over long distances at very low speeds. Materials commonly transferred by this method are hazelnuts, cocoa beans, cereals, candies and glass granules. This system is known to have the advantage of stopping or starting conveyor lines filled with material.
Dense Phase Vacuum Conveying – This type is used to convey abrasive or friable materials at low speeds over short distances. Dense phase vacuum conveying is commonly used to unload materials from railcars and trucks in a fluid state. It has also been used in pharmaceutical and food applications.
Features:
Since the conveying pipe is densely packed with bulk materials, air cannot "slip" through the materials, which is a common reason for the inefficiency of the pneumatic conveying system. If slippage is eliminated, efficiency increases.
When the conveying pipe is filled to its maximum, only a small portion of the particles remain in contact with the conveying pipe at any given time. Most particles remain inside the pipe, reducing pipe wear.
Under a given transfer rate and pipe diameter, the conveying speed can be reduced by increasing the density of the material in the pipe.
principle:
The dense phase conveying pump is a relatively reliable dense phase dynamic pressure pneumatic conveying device for conveying powdery materials under high pressure (below about 1000kPa). There are two unloading methods of dense phase pumps. Bottom discharging is a common method. The material in the tank is fluidized through aeration through a conical surface aeration tank, air injection from a nozzle, or other methods; a fluidized aeration plate layer is provided at the bottom to allow the material to be fluidized. The material is discharged from the upper part of the tank, and the distribution of the conveying gas on different input planes in the tank depends on the properties of the conveyed material.

pneumatic conveying system for powder

How is pneumatic conveying system calculated?

The calculation of the pneumatic conveying system mainly includes the following aspects: calculation of system preset parameters, calculation of transportation capacity, calculation of gas volume flow, calculation of gas pressure drop, etc. ‌
Calculations for pneumatic conveying systems involve several key parameters, including:
Solid-to-gas ratio‌: The ratio of the mass of materials transported per unit time to the mass of air passing through the pipeline at the same time.
‌Air flow velocity‌: including gas velocity, solid velocity, suspension velocity, settling velocity, etc.‌.
‌Conveying distance and pipe diameter‌: affect the calculation of gas pressure drop‌.
‌Material characteristics‌: including the specific gravity, particle size, etc. of the material, which affect the calculation of transportation capacity and gas volume flow rate.