tailieunhanh - Cutting Fluids Part 4

Tham khảo tài liệu 'cutting fluids part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Cutting Fluids 411 Most fluid mixers operate based upon the venturi principle 21 and because of this there will usually be a degree of fluctuation of the dilution if the water pressure should change during its operation - particularly if other equipment within the factory draws water when required. In view of any potential water pressure variation it is normal practice to use a water supply that is not subject to such fluctuations. Many local water authorities may well require that a header tank with an air gap is used to prevent any possibility of contamination of the water mains. When mains water is used many local authorities will provide the necessary water quality information but if another water source is used it will need to be analysed by the user. In Fig. 207 the graph illustrates the results of concentration measurements taken from zero - 6 obtained by different techniques such as Refractometer assessment - more on this apparatus shortly Measurement of the total alkalinity of a product containing nitrate Boron determination by Atomic Absorption AA method Measurement of the total alkalinity of a product not containing nitrate Hypothetical real concentration R set arbitrarily at 3 Determination of anionic emulsifier content b @ water hardness of 10 GH Determination of anionic emulsifier content a @ water hardness of 10 GH Determination of nitride content Determination of anionic emulsifier content a @ water hardness of 30 GH. NB Water hardness can be easily determined with sufficient accuracy using indicators in tablet form while the pH value and bacteria count can be estimated as 21 Venturi principle is A convergent-divergent duct in which pressure energy is converted to kinetic energy at the throat. When utilised with its associated Venturi meter this being a flow meter in which the pressure drop in a Venturi is used to give an indication of flow. Source Carvill 1997 Where in the case of emulsion dilution ratios this fluid mixer arrangement - with the .