Roots blower used for pneumatic conveying ash removal

Roots blower for dust removal, Can roots blower be used for pneumatic ash handling? When designing pneumatic ash handling system with roots blower, it is necessary to ensure that the expected conveying task can be completed first, and at the same time, the type and capacity of the equipment to be used, as well as the related problems and design, should not only depend on the cost of the equipment, but also comprehensively consider the impact of material properties on the quality For example, for some materials, the conditions of various equipment are suitable for pneumatic conveying, but the pneumatic conveying of Roots blower cannot be adopted due to the material containing a lot of moisture and adhesion. Even if the cost of mechanical conveying equipment is large, mechanical conveying mode should be selected. There are also such cases, when conveying certain materials, such as limestone powder to the storage bin in front of the circulating fluidized bed boiler, the power required for pneumatic conveying of Roots blower is large. At first glance, the operation cost is relatively high, but from the perspective of system rationality or production technology, it is better to use pneumatic conveying.

The following requirements should be followed for which method and technology should be adopted under what circumstances:

The economy is reasonable. Generally speaking, mechanical transportation is favorable for short distance transportation; on the contrary, for long-distance transportation, the pneumatic conveying system with roots blower is unfavorable in terms of required power, but in terms of equipment cost, pneumatic conveying system is often advantageous. The equipment cost, power required and operation cost vary greatly with the surrounding conditions, so it can not be compared generally. Meanwhile, it should be noted that with the different conditions of various platform supports and ancillary equipment, the variation range is also large. In a word, when designing the pneumatic ash handling system of Roots blower, the most suitable conveying system and corresponding equipment should be selected according to the specific conditions of the project and after comprehensive technical and economic comparison.

If the conveying output and conveying distance of the system have been determined, the economy of the system generally depends on the mixture ratio of ash and air. From the point of view of energy consumption of the equipment, the power required by the pressure (extraction) equipment is directly proportional to the product of the system pressure and air flow. If the mixing ratio of ash and air is increased, the amount of air to be transported can be reduced. Under the condition that the conveying speed is kept constant, the air quantity for conveying is directly proportional to the square of the pipe diameter, that is, Q ∝ D2, while the system pressure, that is, the resistance of the conveying pipeline is inversely proportional to the inside diameter of the pipe, i.e. P ∝ 1 / D, but not in direct proportion to the ash gas ratio, It is very beneficial to reduce the energy consumption of low pressure (extraction) equipment

Secondly, from the system infrastructure cost point of view, due to the increase of ash gas ratio, the equipment and pipeline inner diameter, support and installation costs can be reduced correspondingly, and the effect of reducing the system infrastructure cost is also obvious. The larger the ash gas ratio μ is, the more favorable it will be for increasing the conveying capacity and obviously the economy will be improved. However, if the ash air ratio is too high, the blockage may occur under the same air velocity, and the conveying pressure will also increase. For the negative pressure and low positive pressure pneumatic conveying system, it may exceed the suction pressure or exhaust pressure allowed by the pressure machinery. Therefore, the value of ash air ratio is limited by the physical properties of materials, transportation methods and transportation conditions.

Roots blower can be used for pneumatic conveying ash. Especially for the pneumatic conveying system of positive pressure roots blower, considering the size and structure of bin pump, the inner diameter and length of conveying pipe, the number of elbows and the amount of air used, the ash gas is more restricted than nature.