Volumetric Dosing Pump Stator Coating for Aggressive Solvents
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pumps with progressive recesses for high viscosity products face compatibility issues with aggressive solvents, leading to increased material costs due to the limited compatibility of rubber stators, resulting in excessive costs for severe applications.
Innovation Solution
A volumetric dosing pump with a rubber stator coated with a polyethylene layer, allowing the pump to handle aggressive solvents while maintaining a reduced cost structure, where the stator is made of thermoplastic rubber through injection co-moulding with the polyethylene coating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rubber stators are used in pumps with progressive recesses, then the pump achieves reliable sealing and continuous accurate delivery, but the pump has limited compatibility with aggressive solvents and requires expensive materials for severe applications
Solution Approach 1:
The stator is constructed as a composite material system combining rubber (providing elasticity and sealing) with a polyethylene coating layer (providing chemical resistance to aggressive solvents). This composite structure allows the stator to simultaneously achieve reliable sealing through the rubber base material and compatibility with aggressive solvents through the protective polyethylene coating, eliminating the need for expensive specialized materials while maintaining performance in severe applications
2Adaptability or versatility
If expensive materials are used to manufacture stators for aggressive solvents, then compatibility with aggressive solvents is improved, but the pump cost becomes excessive and misaligned with reference market levels
Solution Approach 1:
The stator uses a cost-effective composite structure where inexpensive rubber provides the base mechanical properties and a relatively low-cost polyethylene coating provides the necessary chemical resistance. This approach achieves compatibility with aggressive solvents without requiring expensive specialized materials, keeping pump costs aligned with reference market levels while maintaining performance in severe applications
Solution Approach 2:
The polyethylene coating is applied locally on the inner surface of the rubber stator where it contacts the pumped product. This localized application provides chemical resistance exactly where needed (at the product-stator interface) without requiring the entire stator structure to be made from expensive materials, thereby reducing overall pump cost while maintaining compatibility with aggressive solvents
Data Source
Figure 1
Figure 2
AI summary
A volumetric dosing pump (10) is described, for delivering and dosing powdery, liquid, pasty or creamy products, comprising a first duct (5) for entering the product to be dosed, a second duct (9) for exiting such dosed product, an internal recess (12) connected to the first duct (5) for entering the product to be dosed and at least one pumping element with progressive recesses (7), which doses such product, operatively connected to motor means and fluid connected to the internal recess (12) and to the second duct (9) for exiting such dosed product, the pumping element with progressive recesses (7) comprising an external stator case (14) and an internal rotor (15) driven in rotation by the motor means, the internal rotor (15) being shaped as a worm screw with progressive recesses and the stator comprising an internal surface (16) in contact with the rotor (15) and shaped as worm screw.