Goal: DEMCON macawi respiratory systems is a total solution provider of Respiration Technology. DEMCON macawi respiratory systems has a high level of knowledge and experience in development and manufacturing of medical ventilator systems. Recently, new high performance OEM blower modules were developed for use in respiratory or anesthesia systems or other oxygen rich environments.
The MACAWI radial turbine blower for Respiratory applications is specially designed for high pressure efficiency combined with high flow capability. For optimal responsiveness, very low rotary inertia is essential. This has been an important requirement for the choice of the motor and the construction of the impeller of the turbine. Furthermore, the mechanical design has been optimised for simple integration into a housing regarding noise reduction and mechanical vibration absorption.
Approach: Determination of the reliability is an important part of the design process, especially for medical applications. In order to reduce the necessary time for extensive durability tests, in-depth analysis of the strength and dynamics behaviour of the blower module is needed.
Together with the manufacturer the specifications are defined; loads, rotations, environment and lifetime. After modeling and meshing the blower geometry, Finite Element Analysis (FEA/FEM) are performed. The analysis includes the rotational effects to determine maximum stresses and possible unstable behavior during operation cycle.
Making use of Campbell diagrams, representing the system’s response as a function of its oscillation, a whirl speed map was created.
Critical areas are localized and identified, making sure that the critical speeds are well-damped.
Results: From the FEA study, an optimized design is realized which is producible and unstable behaviour is prevented.
Moreover, the lifetime of the product has been extended significantly, giving our client the advantage. The patented technology of the dynamic blower module has now successfully been introduced to the market.