The isocyanate-specific gear metering pump is essentially a high-precision positive displacement pump. Its working principle is based on the fixed volume changes generated by gear meshing, enabling the quantitative delivery of the medium.
Addressing the highly corrosive, high-viscosity, and reactive characteristics of isocyanates, this specialized gear metering pump has been optimized in terms of material selection, sealing structure, and precision control, resulting in core advantages that differentiate it from ordinary gear pumps:
In terms of corrosion-resistant materials, key components such as the pump body and gears are made of corrosion-resistant materials such as stainless steel and Hastelloy. Some models utilize a fluoroplastic lining process, effectively resisting the erosion of isocyanate media, preventing leakage risks caused by material aging, and extending equipment service life. For isocyanate transportation under high-temperature conditions, a heat transfer jacket structure can be equipped to maintain the pump body temperature through heat transfer oil or steam, preventing viscosity fluctuations or crystallization of the medium due to temperature changes.
Sealing performance is a critical guarantee for isocyanate transportation. This type of pump adopts a composite sealing structure of double seals + mechanical seals. The sealing surfaces are precisely ground, and combined with specialized corrosion-resistant sealing components, effectively preventing isocyanate leakage and preventing moisture from the air from entering the pump chamber and reacting with the medium.
High-precision metering capabilities stem from precision manufacturing processes. The gears adopt a multi-tooth involute tooth profile design, with the meshing gap controlled within 0.01mm, effectively reducing the flow pulsation rate. When the number of teeth reaches 20, the pulsation rate can be reduced to below 1.8%. CNC machining ensures the consistency of parameters such as gear modulus and tooth width, controlling the displacement error per revolution within ±0.3%, and achieving a full-range metering accuracy of ±1%, meeting the precise proportioning requirements of isocyanates and polyols in polyurethane production.
