Demineralisation of water

A. Lhassani, M. Rumeau, D. Benjelloun, M. Pontie, Selective demineralisation of water by nanofiltration application to the defluoridation of brackish water, Water Res. 

Ion exchange Liquid Resin with ion-active sites Demineralisation of water... 

A single-stage rotary vane pump ( S0 = 25m3h ) is used to remove residual water from a vacuum vessel which has been cleaned, washed with demineralised water and drained. The pump is fitted with an oil-mist filter. If the exhaust temperature is 75 °C and ambient air ( T= 20 °C, RH = 50%, p0 = 1013 mbar) is used as the ballast gas, calculate the maximum amount of water that can be handled by the pump. (Assume that the pump is directly connected to the chamber.)... 

The available energy flou through five major sections of sulphuric acid plant is given in figure 2. The major inputs to this system are sulphur and pouer, with demineralised (DM) water uet air, process water and cooling water from environment. The useful outputs from the system are sulphuric acid and steam. Losses to environment include heat losses from various equipments blowdown water steam from deaerator vent warm water and stack gas. 

The Annex of the Council Directive on the approximation of the laws of the Member States on extraction solvents used in the production of foodstuffs and food ingredients (88/344/EEC, dated 13 June 1988 as amended (annex I)), is divided into Parts 1, II, and III (below) and lists extraction solvents which may be used during the processing of raw materials of foodstuffs, of food components or of food ingredients. Additionally usage of water (e.g. demineralised water, distilled water, potable water) is also permitted. Regulations and permitted extraction solvents, such as n-octyl alcohol and trichloroethylene, are different in the USA and relevant legislation should be consulted. 

Demineralised water is used primarily to generate HP and MP steam. Recouered condensate from both the condensing turbines and the reformer process is recycled to minimise water consumption. Approximately 140 t/d of water is generated when the crude methanol is conuerted to gasoline in the MTG unit. This water is contaminated with trace quantities of... 

The standard DSC heat-flow calibration procedure with indium is not longer accurate enough, due to the change from a closed to an open cell system (the standard platinum cell lids are removed). Demineralised water is used, therefore, as calibration substance for the vaporisation experiments. The heat of vaporisation of demineralised water was measured six times which each of the sample cups. The average heat of vaporisation measured was compared with the known heat of vaporisation of water (43.9 kJ/mol., [20]) to calculate a correction factor for each sample cup ... 

Water absorptivity was measured by adding demineralised water to 5g of dried alumina until the mixture just became fluid. The amount of water required was measured and the percentage solids calculated. Reproducibility was 1%. 

Boiler Feed Water System—Check the demineralised water plant units, water piping, operation of water pumps, condensate recycle lines, deaerator tank, drain lines, calibration of Boiler Feed Water tank, operation of level indicator, external insulation, location of temperature indicators, etc. Get examined the hydraulic test certificates for all pressure parts and subsequentiy obtain permission from Statutory Boiler Inspection Authority to commission the boiler. Note BFW pumps shall be run one by one to feed water into the boiler. Backpressure shall be created by throttiing overflow from WHB. Water flow... 

Demineralised (DM) water plant DM water is required for the absorption of NO2 to form HNO3 and also for WHRB Will affect the quality of product and operation of WHRB Use of untreated water not advisable... 

Conductivity None (expressed as microSiemens/cm) High conductivity can increase the corrosive characteristics of water Demineralisation, lime softening, RO, ED, NF... 

Sodium Na"" Adds to sohds content of water. When combined with OH, causes corrosion under certain conditions Demineralisation, RO, ED, distillation... 

Process. The big engines of the ship are cooled by circnlating treated demineralised, DM) water in their jackets which can get heated np to 75-80 °C. Sea water... 

The most important application of electrodialysis is the production of potable water from brackish water [82]. Avery special application is the reverse case, the production of salt. In the latter case the concentrate is the product stream whereas in the former case the diluate stream is the product. Moreover, there is an increasing number of industrial applications where ions have to be removed from.a process stream such as demineralisation of whey, deacidification of fruit juices, production of boiler feed water, removal of organic acids from a fermentation broth.lt is even possible to separate amino acids from each other as will be shown below. 

The driving force for the regeneration is the 30-fold increase in the dissociation of water at the higher temperature. The actual regenerants are the additional protons and hydroxyl ions formed on heating. The vital parameters are the buffering characteristics of the resins, the levels of basicity and acidity of the component resins and the way they change with temperature, the oxidation resistance of the resins (especially the basic resin) and the salinity level. The process is well suited to the partial demineralisation of brackish waters. 

S. Loeb and S. Sourirajan, "Sea Water Demineralisation by Means of an Osmotic Membrane," in Saline Water Conversion-11, Fidvances in Chemistry Series Number 28, American Chemical Society, Washington, D.C., 1963. 

Trends in ED appear to be reduction in pumping and direct ED energy, increase in electric current density, and the use of EDR and hybrid processes in plants in which the manufacturer of the demineralisation plant owns and operates the plant, selling water to the user or water distributor. 

In recent years there has been a great increase in the use of demineralised water for rinsing, especially before electrophoretic painting. The demineralised water is generally applied by misting jets at the end of all other pretreatment stages and allowed to flow back into the last rinse tank. 

Reagents. In view of the sensitivity of the method, the reagents employed for preparing the ground solutions must be very pure, and the water used should be re-distilled in an all-glass, or better, an all-silica apparatus the traces of organic material sometimes encountered in demineralised water (Section 3.17) make such water unsuitable for this technique unless it is distilled. The common supporting electrolytes include potassium chloride, sodium acetate-acetic acid buffer solutions, ammonia-ammonium chloride buffer solutions, hydrochloric acid and potassium nitrate. 

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