Current location：Home》News center

Selection of pneumatic ash removal system

When designing a pneumatic ash removal system, the first step should be to ensure that the expected transportation tasks can be completed. At the same time, you should reasonably determine the type and capacity of the equipment used, as well as related issues. When designing, you not only need to consider the cost of the equipment, but more importantly, you need to comprehensively consider the impact of material properties on quality, transportation volume, transportation distance, transportation route conditions, as well as the simplicity and cost of operation and management. For example, for certain materials, various equipment conditions are suitable for pneumatic conveying, but due to the large amount of water contained in the material, it has adhesion and other reasons. Even if mechanical conveying equipment is expensive, pneumatic conveying cannot be used. You should choose mechanical conveying. In some cases, such as when transporting limestone powder to the storage tank in front of a circulating fluidized bed boiler, a large amount of power is required for pneumatic conveying. At first glance, the operating costs may seem high, but from the perspective of system rationality or production technology, energy should be reduced.

Which technology should be used under what circumstances

When the economy is relatively reasonable, mechanical transportation is generally advantageous in short distance transportation; On the other hand, for long-distance transportation, although pneumatic transmission systems are disadvantageous from the perspective of required power, they are usually advantageous in terms of equipment cost. The equipment cost, required power, and operating costs vary greatly depending on the surrounding conditions, so they cannot be generalized. Meanwhile, it should be noted that due to the different conditions of various platform supports and auxiliary equipment, there are also significant changes. In short, when designing a pneumatic ash removal system, it should be determined based on the specific circumstances of the project. After technical and economic comparisons, a suitable conveyor system and corresponding equipment were selected. If the transmission power and distance of the system have been determined, from the perspective of equipment energy consumption, the economy of the system usually depends on the mixing ratio of the mixed gas and air. From the perspective of equipment energy consumption, the power required for pressure (pumping) equipment is directly proportional to the product of system pressure and air flow rate. If the ash air mixture ratio is increased, the amount of air to be transported can be reduced. Under the condition of maintaining the conveying speed, the amount of air to be conveyed is proportional to the square of the pipe diameter, that is, Q ∝ D2, and the system pressure is. Resistance is inversely proportional to the reversal of the tube. The inner diameter, i.e. P ∝ 1/D, is not proportional to the ash ratio. Therefore, increasing the gas/gas ratio and reducing the air volume are very beneficial for reducing the energy consumption of pressure (exhaust) gas equipment. Secondly, from the perspective of system infrastructure costs, due to the gas gas ratio, the inner diameter of equipment and pipelines can correspondingly reduce support and installation costs, and the effect of reducing system infrastructure costs is also significant.

The larger the gas air ratio μ, the more advantageous it is for increasing transport capacity and significantly improving economy. However, if the gas to air ratio is too high, blockages may occur at the same wind speed and the delivery pressure may increase. For negative pressure and low positive pressure pneumatic conveying systems, it may exceed the suction pressure or exhaust pressure. Therefore, the value of ash/gas ratio is limited by the physical properties of the material, transportation methods, and transportation conditions. Especially for positive pressure pneumatic conveying systems, considering the size and structure of the silo pump itself, the inner diameter and length of the conveying pipe, the number of elbows, and the amount of air used, the ash gas is more restricted than natural.