Dirt capacity test

The dirt capacity and pressure drop test are similar in the respect that they can use the same apparatus. The dirt capacity test can be used to determine the dirt holding capacity... 

Membrane filters Down to submicrometre sizes Low mechanical strength and poor dirt capacity. Main use is for extreme cleaning of test rigs, etc., or oil reclaiming. 

In on-line experiments with a plant effluent containing 2% detergents, 1% oil and 0.8% suspended solids (metal, dirt, etc.), tubular modules equipped with UF membranes of different pore-sizes and a microfiltration membrane have been tested. (The experiments were carried out in the gear and axle production of Daimler Benz AG.) As expected, the MF membrane produced the highest flux for detergents. Because of th relatively low retention capacity for oil, however, the use of MF membranes is limited to a maximum oil concentration of about 10% in the concentrate. In this case, the oil concentration of the permeate is about 50 mg/ , contrary to the UF membranes, where the oil concentration of the permeate is independent of the oil concentration of the concentrate up to the phase inversion concentration of about 41%. 

If laboratory tests using a disc of the filter membrane indicate that the filter will have insufficient throughput or life then prefiltration ould be considered. Ideally both filters should come to the end of their service life together, i.e. the dirt holding capacity of both filters should be exhausted at the same time. This enables both filters to be replaced together. A duplex system switching over both prefilter and fine filter is available. 

A 25 mm disc of 57% PAC media was challenged with a stream containing 250 NTU (nephelometric turbidity units) of A2 fine test dnst nntil the differential pressure reached 40 psi. The dirt holding capacity was 18 mg/cm as compared to 17 mg/cm for the nano aliunina media without PAC. It had been anticipated that the considerable amount of PAC in the structure would have an adverse affect on the retention of additional particles. The turbidity of both filtrates was less than detectable throughout the whole experimerrt. In both cases, the filtration efficiency exceeded 99.99%. In addition to demorrstrating... 

There are a wide range of liquid filters used in industries, especially in the filtration of fuel, lubricants, and water. Oil filters are required to compliance with international contamination code of cleanliness for the fluid contamination levels (ISO 4406) and corresponding filtration standards (eg, ASTM D3948-14). The required filtration efficiency and dirt holding capacity for the removal of solid particles, water droplets, and water moisture from oil fuel/lubricants depend on the filtration system used, the required cleanliness levels of the oil, and the oil properties (eg, viscosity and surface tension), which influence the fibre wetting process in liquid filtration. Examples of the standards defining the performance requirements and testing methods for fuel and lubricant filtrations are as follows. 

Apparatus—a dipper with a flared bowl and a handle of conventional lengffi made of a material such as tinned steel that will not affect the product being tested. The dipper should have a capacity suitable for the amount to be collected and must be protected from dust and dirt when not being used. Use a clean, dry sample container of the desired size. 

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