水葫芦粉碎程度对脱水效果影响的中试

水葫芦脱水技术一直是实现其资源化利用的瓶颈,高效率、低成本的挤压脱水设备研发至关重要。试验以自主研发的SHJ-400型水葫芦固液分离机和特殊立式潜污泵(吸口朝上)为基础,采用人工进料方式粉碎水葫芦并通过调节立式粉碎机电动机频率和刀片层数获得不同粉碎程度的水葫芦,首先经过初步试验研究水葫芦粉碎粗细对脱水效果的影响,然后依据脱水设备适宜的水葫芦粉碎粗细要求设计出卧式甩刀粉碎机,并对整套设备(包括粉碎和脱水)进行中试试验。结果表明,随着水葫芦粉碎程度提高,脱水率增加,但与此同时,粉碎的耗能增加,脱水残渣中固形物以及氮、磷、钾等养分流失比例也随之增加,研究发现水葫芦粉碎度为32.92(即粉碎后水葫芦残体长度小于5cm达88%以上)的工况条件较好,所得残渣含水率为83.65%,且试验过程中的总耗能最低,仅6.39kW·h/t,在工程运行中,此结果得到进一步验证,且粉碎与脱水效率更高,总能耗(粉碎+脱水)已降低至2.28～2.72kW·h/t。按照日处理200t水葫芦折算其处理成本为4.5元/t(不考虑设备折旧等其他成本)。可见,此套设备(粉碎和脱水)及工程化技术的研发为水葫芦综合利用产业化的形成提供了技术保障,具有较好的应用前景。

Pilot-scale study on dehydration effect of water hyacinth with different pulverization degree

The dehydration technology of water hyacinth has been the choke point to achieve the utilization of its resources, so it was very important for developing the dewatering equipment with high efficiency and low cost. The selfmade equipment of SHJ-400 including solid-liquid separator and special vertical sewage pump was tested under different pulverization degree of water hyacinth through adjusting motor frequency or number of layers with blade on the vertical grinder. Firstly, influence of dehydration effect of water hyacinth under different degree of pulverization was tested in the laboratory, then the new grinder of horizontal and flail were designed based on requirements for pulverization efficiency of dewatering equipment, and a pilot test on operational effect of the whole equipment (including pulverization and dehydration) was carried out. The results showed that the dehydration rate increased with the pulverization degree of water hyacinth, but excessive pulverization caused more energy consumption of pulverization and more contents loss of dry matter as while as more proportion outflow of nitrogen, phosphorus, potassium and other nutrients of residue. The best operating condition was at pulverization degree of 32.92, i.e. 88% proportion of the remnant body length of water hyacinth was smaller than 5 cm after smashed, where moisture content of residue decreased to 83.65%, the lowest total energy consumption of 6.39 kW·h/t was obtained. In addition, the pilot test had the similar effect to laboratory test, particularly the efficiency of pulverization and dehydration were higher than that of laboratory test, the total energy consumption (including pulverization and dehydration) was reduced to 2.28-2.72 kW·h/t. According to 200 t/d processing capacity, the processing cost was 4.5 Yuan/t (the other costs including equipment depreciation was neglected). So the equipment and engineering technology are applicable for industrialization of comprehensive utilization of water hyacinth.