EWT Water Technology – Water Treatment

EWT Water Technology

Dosing System

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In water treatment, chemical conditioning is a process for altering the behaviour or properties of water by addition of chemical agents. These chemical agents may for example be pH-conditioners, inhibitors, dispersants, coagulants or flocculants, film-forming agents, or biocides.

A dosing system includes equipment for injection, handling, preparation, mixing, and storing of chemical agents. Depending upon the application and the type of chemical agent, this equipment may for example include metering pumps, transfer pumps, pipelines, valves, instrumentation, calibration vessels, storage tanks, agitators, chemical drip trays, chemical vapour traps, etc.

Metering pumps are usually designed as reciprocating pumps, e.g. diaphragm metering pumps or piston metering pumps. For certain applications, water-jet pumps are also used.

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Design Example:

dosing system

Dosing and transfer system for volatile conditioning agents for boiler feed water treatment. Including metering pumps, transfer pumps, agitators, day tanks, calibration vessels, chemical vapours traps, valves, piping, and instrumentation.

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Technical Data:

chemical agent mass flow available within an extremely wide range, depending upon the dilution ratio
chemical agent dilution ratio depending upon application requirements, limited by solubility, handling considerations, and safety considerations
chemical dilution volume flow available from ≈ 0.05 L/h to ≥ 500 L/h, depending upon application requirements and liquid properties
discharge pressure available from ≤ 10 bar to ≈ 250 bar, depending upon application requirements and liquid properties
amount of lines usually 1x100% or 2x100%
storage tank volume available from 35 L to ≥ 10 m³
usually 60 L to 1000 L
storage tank allowable pressure usually atmospheric
storage tank allowable temperature usually ≤ 40 °C
material options metering pump wetted parts • polyvinyl chloride (PVC)
• polypropylene (PP)
• polyvinylidene fluoride (PVDF)
• Acrylglas (PMMA)
• stainless steel (e.g. 1.4571)
storage tank • polyethylene (PE)
• stainless steel (e.g. 1.4306, 1.4404)
pipelines • polyvinyl chloride (PVC)
• polypropylene (PP)
• polyethylene (PE)
• polyvinylidene fluoride (PVDF)
• stainless steel (e.g. 1.4571)
valves • polyvinyl chloride (PVC)
• polypropylene (PP)
• polyvinylidene fluoride (PVDF)
• stainless steel (e.g. 1.4408)
gaskets • ethylene propylene diene monomer rubber (EPDM)
• fluoroelastomer (FKM)
• polytetrafluoroethylene (PTFE)
skid • polyethylene high-density (PE-HD)
• stainless steel (e.g. 1.4301)
control options process control • depending upon application requirements
metering pump stroke frequency • local manual adjustment
• remote, by analogue signal
• remote, by pulse signal
metering pump stroke length • local manual adjustment
• remote, by analogue signal
filling of the storage tank,
preparation of the dosing dilution
• manually
• partly automated, PLC
• partly automated, control circuit

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further downloads

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2018-05-05 • water treatment made in GermanyCompany InformationPrivacy