Case Study: Skid Mounted Centrifuge Separator

Project Background

Our customer is a premiere producer of various spirits including wine. At a major winery located in Monterey County, a combination of centrifuge separators and a diatomaceous earth press filter were used to clarify the wine after fermentation. As production demands and fermentation capacities grew, the winery’s filtration capacity was creating a production choke-point. 

The existing press filter was large, costly to maintain and operate, and had a limited capacity, whereas the separators had a small footprint, were simple to operate with automated controls, and had large flow rate capacities. The customer decided to decommission the press filter and replace it with two new centrifugal separators. 

Placer Process Systems was hired as the general contractor and system integrator to provide turnkey services for all facets of the installation including structural foundation design, foundation installation, separator and auxiliary equipment installation, and electrical services.

Project Hurdles

Separators generate extreme dynamic loads due to the heavy mass of the bowl rotating at high speeds. To restrain these dynamic loads, the separator is typically anchored to a large metal frame embedded in a deep concrete support foundation. The support foundation must be on stable ground with minimal settlement properties to ensure the support foundation and separator remain level over time. The soil to which the new separators were to be installed had the potential to be saturated with water and become unstable. 

This could potentially cause the equipment support foundations to unevenly sink, resulting in an unbalanced separator which would ultimately lead to premature bearing failure. Placer Process Systems needed to create a way to install the separators that would ensure the separator would remain balanced, as well as properly restrain the separator’s large dynamic loads and high frequency vibration.

The project timeline was very tight. There was a small window to install the separators from when they arrived to when they would be needed for harvest. The separators required multiple utilities to operate, and were supplied with auxiliary equipment that would all need to be installed before the separators would be operational. The estimated duration from pouring new foundations to installing and commissioning the separators would not meet the estimated deadline for harvest.

Solution

Placer Process Systems designed, fabricated, and skid mounted the separators to above ground stainless steel frames. By skid mounting the separators, the skid mounting feet could be leveled and bolted to above ground anchor rods instead of attaching the separators to permanent concrete embedded steel frames. As the concrete support foundations would potentially unevenly settle, the separator skids could be re-leveled by simply adjusting the leveling nuts under the skid mounting feet. This resolved the critical issue of the foundation settlement as the skid leveling, thus, the separator balance was independent of the concrete foundation.

The typical installation sequence for a separator is to pour the support foundation with embed frame, wait for the concrete to cure, mount the separator, install auxiliary equipment, complete interconnect tubing, and connect electrical power and instrumentation in series. This timeline structure greatly lengthens the project duration as one task is dependent on another. Skid mounting the separators allowed the installation steps to be performed in parallel rather in series because the skid could be built while support foundation was installed and cured. Once the concrete had cured, the fully assembled separator and auxiliary equipment system skid was immediately installed with only final utility and process line tie-ins left to be completed

SKID Mounted Centrifuge

Results

The addition of the two new separators proved to be invaluable to the Monterey County winery at the commencement of harvest, as they greatly increased their filtration capacity. Without the new separators, the winery would not have been able to meet the average plant production requirements, let alone the increase in production requirements due to that year’s above average grape yield. What would have been a disastrous production year for the winery ended in great success with well above average wine production.

Thorough design and analysis of the separator stainless steel skid frames and anchoring methods showed the separators’ dynamic loads could be properly restrained and transferred to the support foundation. Mechanical run tests proved the viability of the skid mount concept and design, as the separators’ vibration stayed well below the separators’ acceptable vibration limits during heavy solids discharges. Vibration transfer from the separators to the auxiliary equipment was also well below the acceptable limits during heavy solids discharge, proving the skids were properly anchored to the support foundation.

As the support foundations settle over time, our customer will have the ability to maintain the separators’ level and balance by simple adjusting the skid leveling nuts. This design feature will help prevent premature bearing failure throughout the separators’ life span. This will ultimately lead to greater machine reliability and reduce the potential for service and repair downtime during harvest, the time when separators are needed the most.

By performing the separator skid assembly in parallel with the support foundation installation, Placer Process Systems was able to reduce the original project timeline by a matter of weeks. This allowed the winery to have sufficient time to commission the separators before the commencement of harvest.