Prozessdetails
- Overview
- Overhead gas/ interisation pressure measurement
- DP level measurement raw buffer tank
- MIN/MAX level monitoring of formaldehyde gas separator
- Flow measurement at the filter inflow of the formaldehyde
- Temperature measurement in the formaldehyde feed to the polycondensation reactor
- Pressure measurement in the formaldehyde feed to the polycondensation reactor
- MIN/MAX level monitoring of polycondensation reactor
- MIN/MAX level monitoring of polycondensation reactor
- Continuous level measurement polycondensation reactor
- Temperature measurement in the polycondensation reactor and of the generated viscous urea resin
- Pressure measurement in the effluent of the produced urea resin
Production of aldehyde derivates in the organic chemical process
Instrumentation for Monitoring and Controlling the Composition in Aldehyde Derivative Production
The widely used aminoplasts are produced by polycondensation of formaldehyde either with urea (urea resins, UF for short) or with melamine (melamine-formaldehyde resins, MF for short), which is technically obtained in large quantities from urea in preliminary processes. The process for obtaining these resins is very similar in each case: When pre-filtered urea solution is added to the formaldehyde solution, viscous UF urea resin is produced in a polycondensation reactor in an acidic environment, which is used as wood glue in chipboard production, for example. Melamine-formaldehyde resins (MF) are used for thermosetting plastics with high hardness and abrasion resistance - for example for electrical insulation or switch parts or tableware. The production process here involves the intermediate product hydroxymethylmelamine, which is obtained by adding formaldehyde to melamine at low temperatures in an aqueous solution. The final curing of the MF resins usually takes place downstream by adding fillers via polycondensation at temperatures of around 100 °C, mainly with the aid of acidic catalysts. A cross-linked duromer is then formed by splitting off water and formaldehyde.
KROHNE has an extensive portfolio of measuring instruments for the process production of aldehyde derivatives, such as aminoplasts, combined with many years of experience in this sector. To optimise the correct molar ratio of formaldehyde and urea for polycondensation, reliable pressure measurement in the feed, continuous MIN/MAX level monitoring and precise temperature measurements in the reactor are essential. Here, KROHNE contributes proven vibration level switches, highly developed radar level measuring devices and tried and tested resistance thermometers.
Anforderungen
- Process control
- SIL 2/3
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Anforderungen
- Level/ filling control
- Insensitive against clogging
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Anforderungen
- Dry-run pump protection
- SIL2-compliant
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Anforderungen
- Optimised flow splitter for minimum pressure loss
- Many options (heat tracing, purge port etc.)
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Anforderungen
- Reactant temperature
- Thermowell material: 1.4404 / 316L or 1.4571 / 316Ti for standard applications
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Anforderungen
- Chemically resistant materials
- Long-term stable measurement
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Anforderungen
- Optional adapter for high temperatures up to +250°C / +482°F
- Gas-tight feedthrough for toxic gases
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Anforderungen
- TBM Tank Bottom Management
- Ellipsoidal shaped antenna and smooth surface minimise deposits
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Anforderungen
- SIL2-compliant
- Outputs: relay, transistor, 2-wire, NAMUR or contactless switch
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Anforderungen
- Chemically resistant metal thermowells
- Connection heads available up to IP68
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Anforderungen
- Chemically resistant materials
- Front flush process connection