Coriolis Mass Flow Meter for MDI Liquid Measurement

Coriolis Mass Flow Meter for MDI Liquid Measurement

Coriolis Mass Flow Meter for MDI Liquid Measurement: An Irreplaceable "Hardcore" Choice for the Polyurethane Industry

In the production processes of polyurethane, coatings, adhesives, and other chemical products, MDI (diphenylmethane diisocyanate)

 is an extremely common yet exceptionally "difficult" liquid raw material.

It possesses characteristics such as high viscosity, easy crystallization, violent reaction with water, toxicity, flammability, and explosiveness,

 with extreme fluctuations in temperature, pressure, and density. Faced with such a "temperamental" medium, traditional turbine flow

 meters and gear flow meters are simply inadequate—they either jam or cause leaks due to seal failure.

In such industrial scenarios, the Coriolis mass flow meter, with its advantages of directly measuring mass flow rate, being unaffected by

 fluid properties, and resisting high pressure and high temperature, has become the only "hardcore" choice for MDI metering.

Typical Industrial Scenarios for MDI Measurement with Coriolis Mass Flow Meters

1. Core Ratio for Polyurethane Foaming (The Most Critical Scenarios)

In the production of flexible/rigid polyurethane foam, MDI must be mixed with polyether polyols in a strictly controlled mass ratio. The

 precision of this control directly affects the product's foam density, uniformity, and mechanical properties.

Common Applications:

Furniture foam, automotive interior foam

Cold chain cold storage insulation panels

Building insulation materials

If the ratio is out of control, it can lead to foam cracking, substandard density, and even the scrapping of the entire batch. Coriolis mass

 flow meters can achieve closed-loop control of MDI flow, ensuring minimal ratio deviation.

2. MDI Chemical Synthesis and Distillation Purification

In large-scale MDI production plants, stable and precise flow control is required for reactor feed, distillation column reflux, and

 high-temperature heat exchanger piping.

Coriolis mass flow meters are high-temperature resistant and anti-crystallization, and can operate stably for extended periods under heat

 tracing and insulation conditions, ensuring uniform polymerization reaction quality.

3. Tanker Loading/Unloading and Tanker Area Storage Trade Transfer

As a hazardous chemical, MDI requires extremely high accuracy and compliance in long-distance tanker loading/unloading, storage area

 entry/exit, and upstream/downstream quality settlement.

Coriolis mass flow meters are unaffected by temperature and viscosity changes and can replace traditional weighbridges or volumetric

 flow meters, enabling true quality trade transfer.

4. Polyurethane Adhesive and Waterproof Coating Production Lines

Coriolis mass flow meters also perform excellently in the quantitative delivery of MDI concentrate, precise proportioning of AB adhesives,

 and the metering of raw materials for sealants and waterproof membranes, ensuring formula consistency and product stability.

5. High-Pressure Spraying and Sealing Casting Processes

High-pressure conditions such as pipeline anti-corrosion PU spraying, building sealing casting, and high-pressure injection (MDI working

 pressure can reach 50~120 bar) require flow meters with good pressure resistance and sealing performance.

Coriolis mass flow meters have a simple structure and no moving parts, making them naturally suitable for such high-pressure and harsh

 environments.

Key Selection Criteria for MDI Flow Meters

Due to the unique characteristics of MDI, the following points must be considered when selecting a flow meter:

Key Requirements | Description

Anti-Crystallization Design | Piping must be sealed and dry, with a smooth, non-stick inner wall to prevent MDI from crystallizing and

 clogging upon contact with water.

Heat Tracing and Insulation Capability | Supports heat tracing and insulation from 60~180℃ to prevent low-temperature crystallization

 and solidification.

Explosion-proof Rating | Must meet Ex d IIC T4, suitable for Zone 1 hazardous areas.

Material Corrosion Resistance | 316L stainless steel or Hastelloy, resistant to strong isocyanate corrosion.

Sealing Material | Must use PTFE (tetrafluoroethylene); rubber is strictly prohibited (it reacts with MDI and fails).

Unaffected by Viscosity | Measures mass flow directly using the Coriolis principle, unaffected by high viscosity or changes in flow regime.

Conclusion | For flow measurement of challenging media like MDI, the Coriolis mass flow meter is almost the only choice. It not only

 handles harsh process conditions but also directly impacts product quality, production safety, and fair trade.

If you are struggling with MDI liquid flow meter selection, high-temperature heat tracing solutions, or explosion-proof compliance issues, 

please contact us for professional advice and a detailed quote.

Email: [email protected]

WhatsApp: +86 18049841995

Contact Person: Winny