Constant speed filtration test of belt filter

If the industrial belt filter designed belongs to one of the following conditions, the pilot test shall be carried out: 1 The filtering area is more than 50 ㎡; 2 The filter cake is washed strictly; 3 The filter cake is dried strictly; 4 The filter cake is difficult to be removed The pilot filtration device must be able to simulate the working procedure of industrial belt filter, and have a smaller outline size (the filtration area is usually 5-10 ㎡) That is to say, the intermediate test is conducted with a quasi industrial filter It includes pre coating filtration test, constant speed filtration test, filter cake washing, drying and removal test When using ceramic funnel test can't decide whether pre coating is needed or not, pilot plant should be used for pre coating test During the test, circulate between the filtrate outlet of the belt filter and the slurry tank for 3-15min at the speed of 500L If the filtrate fails to be clarified during this period, it indicates that the pore of the filter medium is too large, or that the solid particles cannot form a uniform thick filter cake on the filter medium In this case, the precoating filter should be used In the constant speed filtration test, the flow of filtrate is maintained by the quantitative valve, and the filtrate flow and pressure difference are measured every 3-6min When one of the following three conditions occurs, the constant speed filtration will end: 1 There is a large allowable pressure difference of Zui; 2 The thickness of filter cake reaches 25 mm; 3 The filtration speed drops to the level not allowed In the cake washing test, take one washing filtrate every 3 minutes and measure the solute concentration When the solute concentration measured several times is constant, the best washing effect of Zui is obtained, and the test is finished immediately The drying test of filter cake of belt filter was carried out for 4 times, and the drying time of each time was 5, 10, 20 and 30 minutes respectively In each test, the moisture content of filter cake shall be measured and the curve of moisture content of filter cake to drying time shall be drawn The time corresponding to the low point of the curve Zui is the economic drying time of Zui.