Powder dense phase pneumatic conveying device model and mechanism

Powder is a pneumatic conveying solid particles transported by the gas energy efficient technology of ancient and so far more than 100 years of history. In powder pneumatic

conveying of development history, especially in recent decades, powder pneumatic conveying technology has been rapid progress. In dilute phase suspension

Pneumatic conveying respect, researchers have studied different industries have reached the level of a higher level, and in some parameters have been calculated and its Extendable conveyor

transport mechanism of consensus. Dilute phase pneumatic conveying suspension technology in the building materials, metallurgy, chemical industry has a wide range of

applications. Theory and Practice

Have proved powder pneumatic conveying with mechanical conveying do not have the advantages, such as simple equipment, layout flexibility, easy collecting, etc., but at the same

time, such a dilute phase pneumatic conveying suspension inadequacies gradually raises attention, such as the required power is larger, the bucket elevator

Machine 2-4 times that of the belt conveyor 15-40 times; tube feeding fast, generally about 20-30m / s, resulting in very serious wear and tear duct; solid separation volume and

other. These drawbacks pneumatic conveying researchers to provide another research project - the development of a low energy consumption, solid-gas ratio

, A small amount of gas-solid separation performance superior delivery technology. Recent gradual rise of dense phase pneumatic conveying pneumatic conveying technology has Pipe conveyor

aroused great interest of researchers.
Dense phase pneumatic conveying technology mainly refers to the plug-flow pneumatic conveying of powder in the pipeline is no longer spread out, but the formation of bolt

material, relying on static pressure difference across the material bolt moves forward, with a low, dense and low power index characteristics, and the flow rate due to material

wear and quadratic or tri-

Power proportional to the flow velocity reduces the wear significantly prolonged. With the improvement of solid-gas ratio, pneumatic conveying power index decreased

significantly, is a better method of transport.
1 dense phase pneumatic conveying flow model and mechanism
From the current form of points, dense phase pneumatic conveying embolization can be divided into pneumatic conveying and non-embolic type dense phase pneumatic conveying two

kinds. Non-embolic type dense phase pneumatic conveying mainly dynamic pressure dense phase conveying, material non-uniform distribution in the pipe, into a dense state, but the

material has not been clogged pipes due to

The kinetic energy is still relying on air transport. General air transport speed is 8-15m / s, solid-gas ratio range is generally between 30-70. Embolism style is generally

dense phase pneumatic conveying hydrostatic transmission, refers to the material in the pipeline material within the reactor integrated bolt. Between the bolt material filled

with air, totally dependent

Static pressure difference across the pushing forward. This method of transport air velocity 8m / s or less, the delivery pressure is generally about 0.2MPa, the solid-gas ratio

between 25-250.
(2) Non-embolic type dense phase pneumatic conveying flow model
Most theoretical and experimental embolization of non-dense phase pneumatic conveying consider is the complete suspension flow, but even in a stable horizontal tube dilute-phase

flow, the upper and lower solids mass flow rate should not be ignored compared.
3 embolism style dense phase pneumatic conveying flow model and mechanism
(1) in front of the air feed bolt bolt, the top is dispersed particles, the lower is stationary material layer;
(2) is moved forward bolt material, piled up in front of stationary material layer while leaving a certain amount of the subsequent material. When the material is equal to bolt

left piled material materials, material tied stable conveying; When this balance is disrupted, they may form a long bolt or bolt material material damage.
4 Non-embolic pneumatic conveying device
Non-embolic pneumatic conveying technology is widely used in industry, industrial equipment used mainly spiral pneumatic pump, warehouse-style pumps, pneumatic conveying

fluidized tank installations and turbulence double pipe system.
(1) spiral pneumatic pump: mainly by decreasing pitch screw conveyor and jet chamber. Delivery pressure of about 0.2MPa, solid-gas ratio of 30-40, the conveying speed at 10-20m

/ s between.
(2) Position pump: also known as pneumatic conveying tank sending unit, the most widely used in the cement industry is sending lower feed-in tank, which is a single-chamber pump

system. This system tank and pipeline through the horn adjustable pipe connection, and in the horn adjustable tube conveying air into the tail. In the actual

Application, the delivery pressure is usually about 0.5MPa, solid-gas ratio is between 10-30, and a single-chamber pump is intermittent transportation.
(3) Conveying the fluidizing gas tank: this technique the material is installed in a closed tank for inflatable fluidization, and then press-send it. Examples from the transport

point of view, the use of the average pressure is generally 0.2-0.3MPa, the solid-gas ratio is 20-60.