Plate-and-frame washing problem
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We use diaphragm filter presses for the solid-liquid separation after leaching, with 2-meter large plate and frame filters of the Dark Flow model with a surface area of 800 square meters. We do not employ pulp washing; only plate and frame washing is used, and it seems that the efficiency of this washing method is not high. Are there any others who use this same washing method? Let’s exchange ideas to see how we can improve the washing efficiency Is there a better way? Thank you
The term \"degree of cleaning effectiveness\" is a bit too vague; what’s the level of cleaning effectiveness you currently have? It would be best to have numerical data showing that the washing efficiency when washing directly on the filter press is highly dependent on the operational controls.
Yes, whether the filter chambers of your filter press are fully filled, as well as factors such as the amount of water used for washing, acidity, and temperature, all of these can affect the effectiveness of the washing process. Data speaks for itself; by conducting more data analysis, we will know.
Reply 1# lemanob: It’s also possible to wash the machine itself with water, but the effect is not as good as washing the residue in a slurry tank before filtering it. It also depends on the washing method used by your filter press – whether it washes on one side only or with cross-washing, etc.
Our plate and frame filters previously used central washing as well as diagonal washing; the thickness of the filter chambers was designed to be 4.5 centimeters, but in practice it was 3 centimeters. When filtering acidic slurries, the washing water was initially neutral, and there were three stages of washing – first washing, second washing, and third washing – with the amount of washing water being equal to the weight of the filter cake. The washing effect seemed poor. Now, only one stage of central washing is used, with the washing water being neutral and heated to the same temperature as the slurry
Cross-washing will likely take a bit longer, but whether it’s a diaphragm type or a submersible type, using cross-washing requires more time for estimation; if it’s a chamber-type model, washing by alternately turning off the water valves will yield much better results
We have used box-type systems with single-direction washing; the sediment size is around 120 mesh, and the sulfuric acid content is about 10%. To wash with tap water until the pH reaches 1, it requires approximately 3 to 4 times the volume of tap water as the capacity of the filtration chamber
Observe during cake discharge whether the thickness of the filter cake is uniform across different chambers, as well as in different areas within the same chamber. If the filter cake thickness is not uniform, the water consumption for washing will be high and the washing efficiency will be poor.
Diaphragm filter presses are not suitable for washing; although dehydration can reduce the moisture content, their cost is too high and they pose significant safety risks. For better washing results, tape filters or ceramic filters are preferable, as they allow for multiple washing stages at relatively low costs, with continuous and stable operation
This post seems to be from a long time ago; I saw it before. Why is it showing up again today?
In addition to the water inflow conditions, it is also closely related to the quality of your slurry treatment; another factor is the method of operation!