The bypass in low pressure dense phase pneumatic conveying system consists of the main duct and fixed in the wall at the top of the bypass pipe of the bypass pipe is equipped with drainage - damping plate, the bottom along the axial according to the technological requirements of every certain distance set an opening, through the regulation of the pipeline turbulent state of fly ash conveying. From conveying mechanism is different from the conventional positive pressure pneumatic conveying system, on the change of suspension conveyor for hydrostatic transmission, which changes the conventional positive pressure conveying low concentration, high velocity, easy to wear, easy to pipe wall condition, is to resolve high wear, big output, dense phase conveying abrasion resistant materials (such as boiler fly ash) ideal scheme, represents the advanced level of the ash removal technology today.
The bypass in dense-phase pneumatic conveying system from conveying mechanism is different from the conventional positive pressure pneumatic conveying system, static pressure instead of suspension conveyor for conveying, which changes the conventional positive pressure conveying low concentration, high velocity, easy to wear, easy to pipe wall condition, is to resolve high wear, big output, dense phase conveying abrasion resistant materials (such as boiler fly ash) ideal scheme, represents the advanced level of the ash removal technology today. System through pipelines inside the self-adjusting of by-pass pipe transport the steady state, and to prevent the pipe wall.
The bypass in dense phase pneumatic conveying system is the structure characteristics of the duct, it is made of the main duct and the by-pass pipe of the bypass pipe is equipped with drainage - damping plate, through the regulation of the pipeline turbulent state of fly ash conveying. Conveying air at the same time through the main duct and the by-pass pipe, special design on the by-pass pipe opening in turbulent flow is formed on the main line, in the turbulent state, the fly ash accumulation and segmentation ChengLiao section, the main working principle is as follows:
NgLiao section, the main working principle is as follows: Low speed transmission condition, along with the increase of distance pipeline, the material flow turbulence state are destroyed, and accumulate at the bottom, and pipe main pipeline because of material accumulation and blocking pipe, resistance increases, makes into the by-pass pipe of the air flow to increase. Within the air into the by-pass pipe, due to the pressure difference between the two air jet point is greater than the pressure at the conveying of material between two points, the by-pass pipe of the air to flow into the main duct, back into the main duct air form turbulence in the region. This period of continuous segmentation, mobile, blow, continuous conveying material. Conveying mechanism of the above is not to get through the expensive or complex system, but on a very simple physics implementation: air will toward the direction of least resistance.
High-speed wear is pneumatic conveying are difficult to solve a problem. Due to the particularity of gas-solid two-phase flow, the conventional velocity of calculating system is based on air flow rate, and can't really determine the flow of material, but from the system transmission mechanism which can diagnose the movement speed of the material, the conventional positive pressure conveying system is suspended conveying mechanism, material in suspension speed in compressed air movement, material movement resistance is small, so its movement speed is close to the gas velocity; And by-pass system is in hydrostatic transmission mechanism, the material is half embolism movement, and by-pass pipe inside the upper and shunt airflow, so the rate of movement of the material is much lower than the gas velocity, compared with the conventional positive pressure conveying system, even the same system to calculate the velocity, the material flow rate is far lower than conventional positive pressure conveying system. As we all know, the material of other objects of the wear rate and the material of the movement speed of three direct ratio, the by-pass pipe - low-speed dense-phase conveying system with conventional systems
Blocking pipe pneumatic conveying is more difficult to solve another problem, in case of blocking pipe, will influence the normal operation of the system, and increase a lot of dredge maintenance work, even affect the safe operation of the generator set. Bypass in the operation of the conveying system from another perspective, is actually a wall pipe - open - to open - open again repeated cycle, system in seems stuck under the condition of transportation, is a dynamic process of automatic blowing plugging, and will not happen like conventional positive pressure conveying system blocking pipe shall stop the normal delivery process, be dedicated, and even discharge pipe dredge, time-consuming work fee of material damage, fundamentally solve the problem of blocking pipe.
High ash-gas ratio with low-energy transmission, low energy consumption is the purpose of each conveying system to pursue, in order to achieve better economic benefit. Bypass in dense phase conveying system of the characteristics of low velocity, no blocking by the tube, determines its will in the other delivery systems/gas ratio much higher under the condition of running, even when the design choice/gas ratio is too high, only affect delivery time, will not result in a blocking pipe, and the conventional positive pressure conveying system choose high concentration of blocking pipe conveying easily happened; Because of is high concentration of delivery, and ensure the realization of the by-pass system in conveying mechanism. So, compared with other conventional positive pressure conveying system, bypass in dense phase conveying system realize the high concentrations of transportation, have higher cost performance.
Because of high levels of transmission, certain cases when the system power, low consumption of transportation volume, resulting in ash conveying pipe diameter decreases, the corresponding exhaust dust removal filter bag area reduction, etc., in general, transport the farther the distance, the system output, the greater the economy, the more obvious.
The bypass in dense phase conveying system of high concentrations of transportation and be sent more than one tank at the same time, ash conveying pipe is less, so it need less switching valve, by-pass conveying system in general the same type unit ash conveying pipe is only 1/2 or 1/3 of the conventional positive pressure conveying system, conventional positive pressure conveying system more ash conveying pipe, more discharge valve switch, will cause system layout difficult and more failures, the bracket investment increase, the daily maintenance workload increases.
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