Prevent Equipment Failure and Down-Time With Thermal Analysis
Process equipment is subject to high temperature and pressure as well as heavy external loading and static fatigue. Component failure means costly repairs and down time.
Artisan has the tools and the engineering expertise to help prevent these problems.
Our Finite Element Analysis Tools Include:
- ANSYS CFX and Fluent Computational Fluid Dynamics- (CFD)
- ANSYS Mechanical
- Bentley Auto PIPE (Pipe Stress & Vessel Analysis)
Sample Stress Analyses
Complex piping arrangements were analyzed to better design a large column and a series of five Rototherm®’s. Piping analysis and redesign saved our customer the cost of more than three 20” piping expansion joints. The piping analysis was also used to determine the skirt and lug support loading from all the connected equipment and their supporting structure.
Heat Transfer Analysis
This customer wanted to use a standard steam jet for a non-standard application. The standard design shown in the photo made a sharp transition between the nozzle and a thin conical shell. The fillet weld added a reasonable transition for routine applications, but was unsuitable for rapid increases in temperature. Start-up and operation parameters were severe because steam jet components were being heated at a rapid rate. Our engineers used Transient Finite element heat transfer analysis to learn that standard stainless steel parts would not uniformly heat, causing severe thermal discontinuity stress leading to part failure. The analysis was then used as a redesign tool for optimizing the part for the lowest thermal discontinuity stress.
The improved design for high temperature cyclic operation smoothly blended the cone to the steam nozzle, limiting the transient differential thermal strain. The picture of the 125 lb nozzle insert assembly shows the smooth transition at the 100% radio-graphed circumferential weld seam. The surfaces were also polished to reduce surface imperfection; thus increasing the fatigue limit of the material.
Thermal Stress Analysis
New mechanical components are routinely checked for their effect on equipment performance. The collar shown below was designed to connect to a rotating shaft using set screws. Too much deflection of the collar would cause interference during cold start of the equipment, so the part was analyzed then optimized to eliminate the risk of interference.
Finnite Element Analysis (FEA)
Artisan also has the ability to analyze rotating equipment. For example, rotor design is often governed by rigidity and mechanical seal specifications. In the analysis shown, a 600 lb. rotor was checked for blame strength, critical speed, and dynamic deflection when the mechanical seal specification, on the machine, was changed. FEA allowed redesign of the rotor to minimize deflection, which enabled the rotor to operate within the tolerance of the specified seal.