Development of an air conditioning pre-filter suitable for volcanic regions

研制了两种空气滤清器试验件，并对其性能进行了试验研究。首先，根据惯性集尘理论设计了试验过滤器。使用从樱岛周围几个地方收集的火山灰，检查灰收集系数。当风速小于4 m/s时，带槽除尘器的总除尘系数为70%~ 90%，不带槽除尘器的总除尘系数为65%~ 85%。当风速为3 m/s时，灰粒径0 ~ 75、75 ~ 125、125 ~ 250、250 ~ 500范围内的部分集灰系数分别为22%、75%、98%和100%。经验证，由部分集灰系数合成的总集灰系数与实测值基本一致。接下来，检查湿式灰过滤器的效率。该过滤器的集灰系数大于97%。但是，由于湿灰会随着喷水逐渐粘在除尘器上，最终需要维护，因此只能推荐在灰影响显著的限制区域使用。

Two kinds of trial air filters are producted and the performances of them are experimentally examined. First, trial filters, designed on the theory of inertial dust collection, are produced. Ash collection coefficients are examined using volcanic ash collected from several places around Sakurajima. The overall ash collection coefficients are between 70% to 90% for eliminators with grooves, 65% to 85% for eliminators without grooves, when the air velocity is less than 4m/s. The partial ash collection coefficients, corresponding to the ash diameter regions 0-75,75-125,125-250,250-500 are 22%, 75%, 98% and 100%, respectively, when the air velocity is 3m/s. It is verified that the overall ash collection coefficients synthesized from the partial collection coefficients are similar to those measurements. Next, the efficiency of a wet type ash filter is examined. The ash collection coefficient by this filter is more than 97%. However, as wet ash gradually sticks on the eliminator with water spraying, which will eventually require the maintenance, it can only be recommended to use in the restricted area where the influence of ash is remarkable.