Just as the Dox™ Extruder prepares oilseed material for more efficient mechanical extraction in an expeller press, the Solvex™ Expander prepares oilseed for more efficient solvent extraction.
Through its unique high pressure cooking process, this machine packs flaked soybean into a dense, porous structure that allows solvent to flow more easily through the material, extracting maximum fat to achieve residual oil levels as low as 0.6%. While expansion adds several critical benefits to increase solvent extraction efficiency, these benefits require the expander to run at peak performance.
To capitalize on the potential efficiency boost that an expander can bring, operators should know how to troubleshoot the most common Solvex issues and keep their machines at peak performance — and maximum oil recovery.
To dive deeper into diagnosing problems, download our Expander Troubleshooting Guide: Tips to Fix 12 Common Oilseed Expander Malfunctions
Unlocking the benefits of the Solvex Expander
Let’s start by reviewing how the Solvex Expander works and why expansion is so beneficial for efficient solvent extraction.
The expander is a specialized extruder with a rotating screw that compresses oilseed material inside of a barrel. As the screw turns, it shears the material and creates a high-pressure environment, rupturing the seed cells to free the oil for easier recovery.
Unlike extruders, which rely on frictional heat, expanders inject steam heat to elevate the temperature and rapidly transfer heat throughout the material as it churns inside the barrel. This high temperature, short time (HTST) “wet” cook quickly deactivates enzymes while changing the structure of the protein bonds in the seed material.
Inside the expander, seed material is compressed under pressure and heated above the boiling point of water. When the material is pushed out through the discharge at the end of the barrel, the sudden drop in atmospheric conditions forces the material to expand as the injected moisture vaporizes, creating a network of pores in its place. The expanded product solidifies as it cools, resulting in a dense, porous structure called collets.
Washing these collets with hexane during extraction causes the solvent to flow more easily through this porous structure than flaked soybean material. These collets are beneficial to the solvent extraction process.
- Increased capacity: The Solvex compresses the seeds into a denser form so that more product can fit inside the extractor — increasing its capacity downstream. Specifically, it increases extractor capacity by up to 50%.
- Improved oil recovery: By increasing the exposed surface area of the “expanded” material, the expander allows more efficient solvent flow, or percolation, through the porous collets. The greater exposed surface area facilitates easier oil recovery, which reduces the amount of solvent required per ton of product processed.
- Reduced solvent hold-up: Since less hexane is needed to extract oil from the collets, less residual solvent remains in the oil and meal byproducts after extraction. Specifically, the Solvex reduces solvent hold-up in the solid material by 40% and in the liquid oil mixture by 20%, reducing the additional processing required to recover residual solvent.
- Increased efficiency: Because less heat is required to remove residual solvent from the finished products, expanders can reduce a processing plant’s overall energy consumption. The increased extractor capacity can further reduce energy consumption and lower the operational costs of solvent extraction.
Troubleshooting Solvex issues
Like any industrial oilseed processing equipment, the Solvex Expander consists of many moving parts and other external factors that can impact its operation. Regardless of the specific setback you’re troubleshooting, these four steps are the first lines of defense against possible expander malfunctions:
1. Perform preventative maintenance.
With routine service and inspection, processors can monitor equipment wear and tear to prevent avoidable maintenance issues. Before diving too deep into expander troubleshooting, ensure the internal components aren’t worn out of tolerance, which could impede the machine’s performance.
2. Consider the material feed rate.
Optimal performance requires a steady flow of seed material into the expander. Confirm material is being conveyed into the machine at its rated capacity because excessive or insufficient feed rates can impact the whole operation.
3. Check the steam pressure valve.
Set the steam supply at 120-150 pounds per square inch gauge (PSIG). Low steam pressure could restrict the capacity of the expander or keep the machine from reaching the temperature needed to cook the material thoroughly.
4. Verify the condition of the raw material.
The old saying, “Garbage in, garbage out,” is especially true in oilseed processing. Feeding poor-quality, improperly prepared oilseeds into the expander will result in poor-quality products and other problems. Ensure all material is cleaned, conditioned, flaked, and otherwise pre-treated as needed for expansion.
Solvex service and support
If you’re still experiencing issues after checking those four factors, download Anderson’s Solvex Troubleshooting Guide for more detailed solutions to 12 of the most common expander malfunctions.
If you still can’t diagnose the issue after reading the guide, contact Anderson International for technical service and dedicated support. With over a century of experience installing and troubleshooting tens of thousands of oilseed processing systems around the world, the extraction experts at Anderson can assist with complicated troubleshooting, ongoing technical support, machine maintenance, rebuilds, and repairs.
In addition to supplying replacement parts and offering process audits to identify opportunities for improvement, Anderson provides unmatched experience and expertise to help processors optimize every step of the solvent extraction process.
Contact Anderson today for help troubleshooting and optimizing your Solvex Expander.