The design of a steam ejector vacuum system involves a complex set of technical principles and engineering practices. Here’s a basic design process and related considerations:
First, the design principle
The vacuum system of the steam ejector mainly uses the gas dynamic principle of the conversion of static pressure energy and kinetic energy during fluid flow to form a vacuum. When water vapor with a certain pressure passes through a nozzle (such as a Laval nozzle), it reaches the speed of sound or even supersonic speed, while a vacuum is formed at the outlet of the nozzle. The pumped gas is pumped into the suction chamber under the action of differential pressure, mixed with steam and discharged through the diffuser. A higher vacuum level can be obtained by connecting multiple ejectors in series and adding a condenser in between.
Second, the design steps
Determine the system requirements
Determine the vacuum requirements of the system, the pumping volume, the conditions of the working steam, the conditions of the cooling water, etc. These parameters will have a direct impact on the design and selection of the injector.
Choose the right injector
Choose the right injector model and specification according to your system needs. Efficient and stable steam ejectors, such as the German Körting steam ejector, can be considered.
Design the injector structure
According to the performance parameters of the selected injector, design the internal structure of the injector, including the nozzle, diffusion part, diffuser and other parts. Make sure that the steam can flow smoothly and create a vacuum inside the ejector.
Determine the condenser configuration
In cases where a higher vacuum level is required, consider adding a condenser between the ejectors to condense the steam and further increase the vacuum level.
System Integration and Optimization: Multiple ejectors and condensers are integrated according to the design requirements to form a complete steam ejector vacuum system. Through customized modeling and analysis, the optimal modular device is selected to ensure that the system configuration is reasonable and the performance is stable.
3. Considerations
Steam consumption and heat transfer efficiency
Steam consumption is directly related to the amount of heat required, and it is necessary to ensure that the design of the steam injection system ensures maximum heat transfer efficiency and avoids heat loss caused by steam bubbles bursting on the surface of the liquid and escaping into the atmosphere.
Vacuum stability and safety
The vacuum system of the steam ejector should have good vacuum stability and safety, which can avoid safety problems such as cavitation of the vacuum pump and rotor breakage.
Maintenance and operation costs
In the design process, the maintenance convenience and operating cost of the system should be considered, and the components and equipment with simple structure, low maintenance and stable performance should be selected.
4. Testing and verification
Once the system design is complete, actual testing and validation work is required. By building an experimental platform or testing in actual application scenarios, it is verified whether the performance indicators such as vacuum degree and pumping volume of the system meet the design requirements. At the same time, the system is optimized and adjusted according to the test results to ensure that the system performance reaches the best state.
In conclusion, the design of a steam ejector vacuum system is a complex and important engineering task that requires a comprehensive consideration of multiple factors and technical requirements. Through reasonable design and optimization, we can ensure that the system has good performance and stability to meet the actual application requirements.
