Fresh Water Distillate Pump

Fresh peeing Distillate essenceINTRODUCTION . on that point was MOD vas on the port and this vessel required a sportsmanlike piss musical arrangement for the 50 crew on the ship. So i support to make a clay to issue impertinently peeing on that ship. But the problem is that the ship is at port and there is lot of groundless present in the port ocean wet such as organic knock get by means of which fit mainly garbage ,untreated sewage which poop platterharge directly or indirectly in the ocean.treaces of dangerous metals also present mercury,cadmium,,chromium these take aimheaded metals be dangerous to health and also to the environment. loaded down(p) metals such as atomic number 30 and lead may causes corrosion .beside of these there was s single anthropogenic source of waste present which are listed be imp everywhereished. minelaying effluentsDomestic effluentsIndustrial effluentsShipping activities including those of goised boats and stooloes.Fertilizers pesticidesAtmospheric sources such as gas flaring, incineration of domestic waste manly garbage.Petroleum industries activities.According to uk piddle hand over regulation the perctange of close to heavy metals must be at certain levelCALCULATIONBefore choosing any generator I have to mastermind the peeing which fulfil the requirement of 50 persons.In a ship one person potentio thou MAXIUM 600 to 800 litres per twenty-four hours. A person whoremaster use the fresh weewee for subspeciesing clothes, washing utensils, wash room, insobriety, cooking, bathing, and etc.If we calculate the fresh body of weewee for the 50 persons is800*50= 40000 litres per solar dayso i have to chose a system which is capable for the turn break finished of minim 40000 liter per dayTYPES OF FREH WATER GENERATORin an efficient locomotive, muchover about half of the warming in the fuel is converted into useful mesh some of the wake energy is lost in the cooling systems and exhaust gas. b ut some of the set off lost is vulcanised . the Modern postgraduately pressure charged engines have a large amount of energy in scavenge pipeline cooling wateer and this can be provide as the source of alter to the bunkering .an oppositewise source of heat is jacket wet cooling and it also contain considerable amount of heat and this heat can be recovered in the fresh pissing evaporator system which ope appreciate at the pressure giving a corresponding saturation temperature fo wet clinical depressioner the the jacket water supply entering in to the heating mass medium .gasses dissolved when water is heated to its saturation temperature.There are deuce methods for generating fresh water,1.Reverse Osmosis2. distillment.is generally utilize were large quantities of relatively junior-grade part water is required. distinctive examples of water produced areTreatmentTotal HardnessCalcium HardnessSilicaSodium ChlorideTDS sea Water250200141500015000EvaporatorReverse Osmo sis205After Demineraliser0Trace. distillationThe most comm moreover use fresh water coevals is evaporative distillation, which uses engine jacket cooling water or go heat from exhaust or gas fired boilers to evapo sum up sea water, which is thusce condensed into fresh water. Evaporation distillers comes in two main designs, 1.multistage flash2 multi consummation evaporators.Simple unmarried effect evaporatorThe system above shows an evaporator characteristicly heated by Main Engine Jacket water with means to supply steam when the engine is shut downSingle and multi stage supply distillation was one of the early causes of fresh water generation. It uses heat clear uping by means of submerged coils or electron supply bundles immersed in sea water to produce the distillate, which when condensed becomes the fresh water.Single Stage Flash Evaporatorflash evapouratorit exist of two parts1.condensor2.evaporatorgenerally the heating method utilize is main engine heat or by heating oil usually the water boils at c degree. But in the freshwater generator the water inside the system usually boiled at 60 to 70 degree. By utilise ejector or edecutor.basically an alternative arrangement to the shell evaporator is the flash evaporator were heating takes place externally, the wild seawater enters the impression pressure chamber into a weir where some of the water flashes off. Water over executeing the weir is both out or expended on to a guerrilla stage. Multi stage units with each stage maintained at a lower pressure allow modify efficiency and high outputs. to cross off the percentage of brininess salinoemetre is used. its is important to use salinometere because if the percentage of coarseness in water became high because it can retrieve it and raised the alarmMulti Stage Flash Evaporatorflash flow diagramrin this make we use two evaporation stages in order to get a better typical multi stage flash system is based upon preheating of a pressu rised sea water germinate, or more typically a recycle brine stream to which the feed sea water is added the stream is heated in the heat input section brine heater. Double stage FWG is similar to the single stage FWG, the only difference being that the unharmed single stage process is repeated twice in 2-stage generator From here the recycle stream is passed into the first stage of a series of flash chambers. Here the pressure is released, permitting a portion of the brine stream to flash to anatomy salt- innocent(p) vapour which is condensed to give the fresh water. In condensing the vapour gives off its latent heat to the recycle brine stream. From the first stage the flashing brine stream is passed to the second stage which is kept at a slightly lower pressure more vapour flashes off. In the same way the flashing brine stream passes to the next stage and so on through the sow with a portion of the vapour flashing off at each stage. A heat balance shows that the heat supplie d in the brine heater has to be rejected. This is done in the last two stages of the plant which are cooled by a sea water stream which subsequently passes to waste.Modern Developments. oversize Multi-effect Alfa laval evaporatorIn 1990 Alfa-Laval Desalt introduced its D-TU concept-a ME desalination system based on tube type distillers, by using the evaporation under vacuum with the rising film principle. This is thath means the inner surfaces of the tube are invariably covered with a then film of the feed water . heating medium is circulates on the right(prenominal) of the tubes in the heat exchangerss.and The vacuum is created by water ejectors connected to each effects. A meshled amount of sea water is led to the bottom of each of the effect. where it is mixes with the brine from the previous effect and into the tubes in the heat exchanger, where it is heated. The generated vapors enter a separator where the brine droplets from the wet vapour are separated. The dry vapour pas s through the separator to the following effect where they condense. The remaining sea water which has been converted to brine, flows to the next effect as feed water. The brine is taken out and drop awayd overboard. The latent heat in the blue devils from the previous effect is used as a heating medium in the following effects. The process continues until the last effect where the generated vapours condense cooled by sea water. The condensate vapours flow from one effect to the next, and are retained in a collecting tank as distilled water. If a low temperature evaporator is to be used for domestic purposes certain restrictions apply. Operation is not allowed within 25 miles of the coast or 50 miles of an estuary. Chromate jacket water treatment must never be used. The condensate must be treated in order to destroy bacterium. Care must be taken if chemicals are used to inhibit marine growth in pipe work.Vapour CompressionThe boiler section is ab initio modify with fresh water. When the system is operating feed water is supplied via the level control valve. Hot steam is created in the boiler which passes over into the main section. Here the steam is mixed with a brine spray. near of the steam is condensed and some of the brine spray is flashed off. The combined steam passes over to the vapour section via a scrubber. Flow of vapour occurs due to the action of the compressor which increases the vapour pressure increaseing its saturation temperature.Reverse OsmosisOsmosis describes the process whereby a fluid will pass from a more dense to a less dense resolvent through a rig-permeable tissue layer. It is very important to the water absorption processes of plants. RO is a process which uses a semi permeable membrane which retains both salt and impurities from sea water man allowing water molecules to pass. Filtration of up to 90% is possible thus making the produced water unsuitable for boiler feed without further conditioning. Improved quality is possib le using a two or more pass system.diagram showing osmotic headThe parchment paper acts as the semi-permeable membrane and allows the water molecules to pass but not the larger salt molecules.Reverse osmosis is the process whereby a pressure greater than the osmotic head pressure is applied to a solution of high density. Fluid is forced from the high density side to the less dense side. For desalination plants the pressure is applied to sea water and the water is forced through the semi-permeable membrane.The semi permeable membrane which is typically make of polyamide membrane sheets wrapped in a spiral form near a perforated tube resembling a loosely aggravate toilet roll.Design of the cartridges is therefore such that the sea water feed passes over the membrane sheets so that the washing action keeps the surfaces clear of deposits. A dosing chemical is also injected to assist the action.Make up of membraneThe two membranes sealed on the out three edges, enclose porous under-la yer through which the filtrate spirals to of import collecting tubeSchematic of RO plantPressurised feed water passes lengthways through the tubular spiral wound membrane element. Freshwater permeate travels through the membrane layers as directed along a spiral bath inot a central perforated tube, while brine is discharged out the end of the membrane element..The fluid could be water and the solutions sea water. Under normal conditions the water would pass from the less saline solution to the more saline solution until the coarseness was the same. This process will cease however if the level in the more saline side raises to give a difference greater than the Osmotic height.For practical use to allow the generation of large quantities of water. It is necessary to have a large surface area of membrane which has sufficient mechanized strength to resist the pressurised sea water.. The material used for sea water purification is spirally wound polyamide or polysulphonate sheets. One problem with any filtration system is that deposits accumulate and gradually blocks the gain vigor. The sea water is supplied at a pressure of 60bar, a relief valve is fitted to the system. The Osmosis production plant is best suited to the production of large quantities of water rather than smaller quantities of steam plant feed quality.Pre-treatment and post treatment.Sea water feed for reverse osmosis plant is pre-treated in the lead being passed through. The chemical sodium hexa phosphate is added to assist wash through of salt deposits on the surface of the elements and the sea water is sterilised to remove bacteria which could otherwise become resident in the click. Chlorine is reduced by compressed carbon filter while solids are removed by other filters. Treatment is also necessary to make the water drinkable.The disc tube module is supposed to have the main advantage over the spiral wound type in that it avoids the need for the difficult cleaning processes required. W ith long lasting membranes, typically 5 years and in built cleaning system the unit will recover 30% as pure water from sea water passing through itCoil or Tube Seawater EvaporatorThis is a upstart version of the type used when I was at sea in the 1960s they used heating coils in those days as opposed to the pipe nest heaters of today. The coils used to become surpassd in salt, with the attendant loss in output of distillate. I was in charge of the vaps and I remember the quondam(a) chief coming down to the engine room on my watch and balling me out for the downturn in distillate. We were having problems with the boiler feed water purity (next article will cover the testing and treatment of boiler feed water) so I was blowing down the boiler regularly with the associated make-up requirement meant we needed more water pronto. Anyway I took him up to the vaps and showed him the scaling on the heating coils, reminding him that I was philiaing Foss chemicals into the beast to submi t and break this away. He pushed me aside and shut off the seawater supply opening up the steam supply which rapidly dried the salt layer on the coils. He then opened the seawater inlet and hey presto the salt scale cracked and fell of the coils. I used this system some(prenominal) times until I was up for Seconds ticket and examiner wasnt too pleased to hear of this method, called the old psyche several unprintable names. Today we dont have to resort to these measures as there is an innovative device which uses a material that emits oscillations counteracting the natural seawater oscillations, thereby altering its properties and preventing atomic number 20 carbonate scale. (I will note the website brood in the relevant section I am too old for this new technology). A tube and coil evaporator consists of a steel vessel which has a nest of heating pipes near the bottom of the vessel being fed by steam or, hot water from the main engine. There is a tube electrical capacity coole d by seawater installed near the top of the vessel. A vacuum is drawn in the vessel by air ejectors operated by steam or pressurised seawater. Seawater is fed into the evaporator just covering the heating pipes. Heat is supplied to the pipes and, this combined with the vacuum conditions begins to boil the seawater producing steam. The steam rises up through a demister into the tube condenser where it is evaporated to distilled water. This is collected and pumped via the salinometer to the storageEVAPORATOR SCALE.There are numerous types of evaporators all working to produce pure water with concentrated sea-water as waste. This concentration effect can lead to the formation of negative scales within the evaporator. Over concentration is usually prevented by having a continuous stream of sea-water passing through the unit thus maintaining a satis positionory dilution of the sea-water side of the evaporator. However, because of the high salt content, when sea-water is elevated to tempe ratures above 30 C scales can begin to form on heat transfer surfaces. Additionally as the absolute majority of evaporators operate under vacuum there is a tendency for the make-up water side to foam, which can give rise to carry-over and contamination of the pure water stream. quartet scales which are principally sort in evaporators areCalcium Sulphate (CaSO4)-1200ppm, scale formation is principally on density, remains in solution under 140oC and/or 96000ppm.The worst scale forming salt forming a thin hard canescent scaleMagnesium Hydroxide Mg(OH)2remains in solution below 90oCMagnesium Bi-Carbonate 150ppmsoluble below 90oC, forms a soft scale, prevention by keeping operating temperature of evaporator below 90oCAbove 90oCbreaks down to form MgCO3 and CO2 and then Mg(OH)2 and CO2Calcium bicarbonate Ca(HCO3)2 180ppmSlightly solube, above 65oC breaks down to form insuluble calcium carbonate forming a soft white scale. scale formation prevented by chemical treatment Ca(HCO3)2 = Ca + 2HCO32HCO3 = CO3 + H20 + CO2If heated up to approximately 80oCCO3 + Ca = CaCO3If heated above 800CCO3 + H20 = HCO3 + OHMg + 2OH = Mg(OH)2Hence if sea water in the evaporator is heated to a temperature below 80oC calcium carbonate predominates. If it is heated above 80oC then magnesium hydroxide scale is deposited.Sodium Chloride 32230 to 25600ppm -generally ignoredSoluble below 225000ppm forms a soft encrustation, free ions promote galvanic action. It is unlikely to precipitate and is easily removedSupersaturationThis is where the concentration of dissolved salts exceed their solubility at the particular temperature encountered and precipitation begins to occur. When deposition occurs under these conditions heavy scale deposits can rapidly build up and lead to a loss of heat transfer efficiency. Scale deposition due to supersaturation is a great deal localised in areas of elevated temperature such as heat transfer surfaces in heat-exchangers. This is because of localised over c oncentration of salts with approve to the temperature of the thin water layer at the surface of the metal. Scale deposition can therefore occur on heat-exchange surfaces even when the conditions in the bulk of the water are not scale forming.FINALLY SELECTED GENERATORVACCUM VAPOUR COMPRESSION FRESHWATER GENERATORMAKER.. ALFA LAVALTYPE.. ORCA OFFSHORE SERIESCAPACITY20-70m3/per dayvacuum vapour compression is the efficient method of production of fresh water for both alcohol addiction and other use. by using this method we can convert the sea water in to fresh water by vacuum distillation process using electricity. The system has simple compact designee made from titanium heat exchanger plates with combined fresh water and feed water system. the system has low maintance cost any work on start and forget operation .and can produced very high quality of fresh water .BASIC Equipment.titanium plate heat exchanger for the combination evaporator and condenserstainless steel distiller shel l,air ejectorfreshwater pumpcompressorUL approved panelbuilt in freshwater quality monitoring system.ADDITIONAL Equipmentfresh water pH adjustment filter.silver-ion or we can say UV sterilisersVACCUME DISTILLATION PROCESS.vacuum distillation is the process use to convert sea water in to fresh water. by this process constant supply of fresh water with low salinity level and be achieved with continuous controlling the water quantity.WORKING PRINCIPAL .0feed water enter in to the lower section of the plate packs.plates is warmed by heating medium, heating medium is either a jacket water cooling medium or a closed circuit heating mediumwater is then evaporated at 40-60 degree centigrade in the vacuum of 85-95 %the vapour produces is raised between the plates in the middle section of plate pack. At this point seawater is almost completely removed.these droplet falls congest in to the brain sump by the gravity at the bottom of the fresh water generator.only the clean fresh water can ente r in to the condenser section and the water is cooled by flow of sea water. at that point vapour is condensed in to fresh water and pumped out by the fresh water pump.GHARP SHOWS THE % TONS PER DAY PRODUCTIONTechnical specifications (standard units without optional equipment)Water shaper type ORCA Offshore 20 ORCA Offshore 30 ORCA Offshore 40 ORCA Offshore 50 ORCA Offshore 60 ORCA Offshore 70 aloofness (L) mm/inch Width (W) mm/inch Height (H) mm/inchDry lean kg/lbsOperating weight kg/lbs FW pump motor kW/hpBrine pump motor kW/hpSW pump motor kW/hp (option)Circ. pump motorElectric power (kW installed)Power consumption kwh/m3 fresh water Fresh water qualityDimensions *)THE tipple SHOWS ORCA OFFSHOREE SERIES WITHOUT OPTIONS2450 / 96 2150 / 85 2400 / 943700 / 8175 3865 / 85211.3 / 1.7 1.3 / 1.7 12.5 / 1 1.9 / 2.678.518WHO standard, less than 5 ppm NaCl2800 / cx2150 / 852400/944000 / 8818 4185 / 92261.3 / 1.7 1.8 / 2.4 12.5 / 17 3.6 / 4.98118SLOW SAND FILTER (SSF) FOR THE REMOVAL OF dumb METAL.Slow rachis filters (SSFs) are probably the most effective, simplest and least expensive water treatment process. Micro-organisms and other particulate materials are effectively removed by SSFs. Considerable split upment has been done on SSFs with respect to particle remotion, but only a some works have been reported in the scene of the removal of heavy metals which are a severely toxic pollutant of surface waters. No extensive lab or pilot studies have been carried out to determine the performance or the mechanisms of removal of heavy metals by SSFs. This research is concerned with an experimental investigation of the removal of heavy metals from surface water by SSFs. Four laboratory scale SSFs were built and run according to standard design criteria. Removal of four park heavy metals copper (Cu), chromium (Cr), lead (Pb) and cadmium (Cd) were monitored. The filters were fed synthetic water made from tap water mixed with settled sewage, and each filter was dosed with one of the heavy metal salts. The concentrations of Cu, Cr, Pb and Cd in the influent were selected as 10 mg/l, 100 g/l, 60 g/l, and 100 g/l respectively considering their relative toxicity and WHO guidelines in drinking water. Settled sewage was added to change the total organic carbon (TOC) of the feed water. The reduction of heavy metal concentrations were monitored at various TOCs, filtration judge and filter bed depths. The results showed that SSFs succeeded in removing heavy metals from water. The removals of Cu, Cr, Pb and Cd at the conventional flow rate and filter depth are 99.6,97.2,100 and 96.6 % respectively. The results also showed that an increase in TOC in the feed water improved metal removal while increases of flow rates caused a decrease of the removal of metals. The removal of heavy metals also decreased with a reduction in sand bed depth. The optimisation of design parameters for SSFs for the removal of heavy metals depends on the individual heavy metal and on the TOC content of the feed water. Model equations were certain for, and linear correlation was observed between each of the three control parameters and the removal of the selected metal. The removal of heavy metal by SSFs was achieved through the combination of a number of mechanisms. Settlement, adsorption to both sand and organic matter and microbialWORKING PRCEDUREslow and sand filter work through the formation of a layer know as hypogeal layer or schmutzdecke .hypogeal layer contain microorganism that remove bacteria and trap condiments particles.it consist of bacteria,fungi,portozoa,rotera and a range of aquatic insect larva. the hypogal layer provides effective purification in potable water treatment.as the water passes through the hypogeal layer particles of foreign matter are pin down in the mucilaginous matrix and dissolved organic material is adsorbed and metabolised by bacteria, fungi and protozoa. Water produced form a well managed slow sand filter is free from h eavy metals and other hazards. Slow sand filter are simple, are easily used by small systems, and have been adapted to case plant construction . Slow sand filter are similar to single media rapid-rate filters in some respects, but there are crucial differences in functional mechanisms(other than the obvious difference in flow rate) the schmutzdecke removes suspended organic materials and microorganisms by biodegradation and other biological processes, instead of relying solely on simple filtration or physic-chemical sorption. Advantages of slow sand filtration include its low maintenance requirements (since it does not require backwashing and requires less frequent cleaning) and the fact that its efficiency does not depend on actions of the operator. However, slow sand filters do require time for the schmutzdecke to father after cleaning, during which the filtration performance steadily improves this interval is called the ripening period. The ripening period can last from sextup let hours to two weeks, but typically requires less than two days. A two day filter-to-waste period is recommended for typical sand filters . Since few remedies are available to an operator when the process is ineffective, slow sand filtration should be used with caution and should not be used without pre treatment or process modifications unless the raw water is low in turbidity, algae, and colour . Package plant versions with a granular activated carbon layer hardened beneath the slow sand filter can absorb organic materials that are resistant comme il faut to biodegradation to pass through the schmutzdecke. When used with source water of the appropriate quality, slow sand filtration may be the most suitable filtration technology for small systems (6). Slow sand filtration has demonstrated removal efficiencies in the 90 to 99.9999% range for viruses and greater than 99.99% for GuardiaFILTER DISCRUPTION.Square tankMedia depth 2-3 ftSurface area Filtration rate 2-10 gal/min-ft2Flo w through filter 350-3,500 gpmBackwash frequency every 24 houreCALCULATIONWe have required maximum 40000 litter per day production per day. and the filtration rate of this filter is max 51000 litter per day which fulfil our requirement. and we have to put two filter in parellal for the standby and maintaince purpose. So that if one filter stop working we can use the other standby filter to run the system as per requirement.IMPORTANT POINTsthere is one go around line in slow sand filter in front the water enter in to the sand filters. and this bypass meet the discharge line of distilled pump. The reason for this bypass is that if the ship is in the sea we can open the bypass valve and the fresh water then groovy go to the mineraliser unit. because in the roiling and pitching condition the slow sand filter does not work properlythe sand filter unit is completely fixed with proper fitting. so that when the main engine runs it does not move from his place.one the important is that th e system will take at least 2 day to start working .so for days the ship master has to arrange some external sources of drinking water.CLEANING METHODThere is two method of cleaning of sand filter1. the top few millimetres of fine sand is scraped off to expose a new layer of clean sand. Water is then decanted back into the filter and re-circulated for a few hours to allow a new Schmutzdecke to develop. The filter is then filled to full depth and brought back into service2. The second method, sometimes called wet harrowing, involves lowering the water level to just above the Schmutzdecke, stirring the sand and thereby suspending any solids held in that layer and then racecourse the water to waste. The filter is then filled to full depth and brought back into service. Wet harrowing can allow the filter to be brought back into service more quickly. POSITION.we can fit the sand filter before the discharge of distilled pump.CHEMICAL TREATMENT.VAPTREAT.chemical known as vaptreat is add i n to the system before the point where sea water is going inside the system .because this chemical make the sea water soft.IMPORTANT PROPERTIESOdour OdourlessAppearance Liquid, pale yellow, soluble in waterContact with eyeball Mildly irritating to eyesContact with skin In cases of severe exposure, irritation may developInhalation Vapours or aerosols may cause irritation of eyes, nose and respiratory tract white plague May cause gastro-intestinal disturbancesMINERALISER AND CHLORINE UNITAfter the discharge of distilled pump the water then pass through the mineraliser after the mineraliser chlorine is added to the water.capacity of mineraliser=3800liter/hourcapacity of chlorine unit.=3800liter/hourPUMPS REQUIREMENTSEjector PumpThe ejector pump is a single-stage centrifugal pump which supplies thecondenser with sea water and the brine/air ejector with jet water as well asfeed water for evaporation.Fresh Water/Distillate PumpThe single-stage centrifugal fresh water pump extracts the di stillate from thecondenser and pumps it to the fresh water tank.POSITION OF EJECTOR PUMPThe pump is fitted after the suction of low sea chest. because at the low sea chest suction there is no oil present .and is the best point of taking the main sea water suction .TYPE OF PUMP.TEHNICAL DATACASING.. Cast iron, Nodular cast iron, Bronze, innoxious steelIMPELLER.. Cast iron, Bronze, Stainless steelMAXIMUM CAPACITY.850m3 per hourMAXIMUM DELIVER HEAD105MMAXIMUM luculent TEMPERATURE120 CENTIGRADEMAXIMUM PRESSURE.1000KPaMAXIMUM SPEED3600 rpmSalinometerThe salinometer continuously checks the salinity of the produced water.The alarm set point is adjustable. salinometer continuously check the quality of the distillate, a salinometer is provided at the outlet side of the distillate pump.If the salinity of the produced fresh water exceeds the chosen maximum value,the solenoid valve is activated to automatically dump the distillate to the bilgeand an alarm is soundedControl PanelThe control panel contains motor starters, running lights, salinometer andcontacts for remote alarm.DISTILLED WATER TRANSFER AND DISTRIBUTIONEach fresh water generator distillate pump discharges through a salinometerand a flow meter. Positioned before the flow meter is a solenoid valve. Thisopens when the salinometer detects too high a salinity level, diverting thedistillate pump output to the bilge.The discharge from the FW generators flows to either the distilled water tankwhich is situated in the steering gear room on the maneuver side though inletvalve or to the fresh water tanks which are both situated on the port and starboard sides of the steering gear room.The distilled water tank supplies water to the boiler feed water tank via valveFresh water produced in the generator that is to be used for domesticpurposes is directed through a mineraliser and a chlorination sterilising unitbefore entering the fresh water tanks. The fresh water tanks supply water tothe d