我厂密实砌块车间采用自然沉淀法进行粉煤灰脱水。原来在沉灰池下铺设砂滤层为过滤介质,但在长期使用中,发现池底全部采用黄砂则当池内粉煤灰快拉完时,拉铲斗子就会将池底下的黄砂拉掉。而我厂40×15×3.3米的池子每月要周转4～5次,所以池底新铺上的黄砂用不多久就会被拉铲拉掉。同时还会拉掉真空管子上的钢丝网布,导致池底需重新翻修,而每次翻修需人工材料费约1.2万元,据统计使用寿命仅半年左右。为此,我们对粉煤灰池底部结构进行了改造,采用我厂生产的24×38×88厘米的密实砌块来代替大部分黄砂,结构布置见图1。这样既不影响粉煤灰脱水效果,并且大大延长了粉煤灰沉 Our factory dense block workshop uses natural precipitation method to dewater fly ash. Originally, the sand filter layer was placed under the sink tank as the filter medium. However, in the long-term use, it was found that all yellow sand was used at the bottom of the pool. When the fly ash in the pool was pulled quickly, the bucket shovel would pull off the yellow sand under the pool. The 40×15×3.3 meter tank of our factory has to be turned around 4 to 5 times a month, so the yellow sand on the bottom of the tank will be pulled out by the shovel sooner. At the same time, the wire mesh on the vacuum tube will be pulled off, resulting in the need to renovate the bottom of the pool, and the artificial materials cost about 12,000 yuan for each renovation. According to statistics, the service life is only about six months. To this end, we have reformed the bottom structure of the fly ash pool and replaced most of the yellow sand with 24×38×88 cm solid blocks produced by our factory. The structural layout is shown in Figure 1. This will not affect the dewatering effect of fly ash, and greatly extend the fly ash