Cannabis

Our experience in building equipment to the sanitary ASME-BPE standard and 3-A Sanitary Standard ensures that the stainless steel heat exchangers that we design will be safe for processing products being consumed by their customers.

Our customers also value the safety standards that we follow, including the ASME Boiler and Pressure Vessel Code, which gives them the peace of mind that our exchangers will safely hold up to the most rigorous cryogenic and high temperature applications when subjected to vacuum and high pressure conditions.

Enerquip designs each exchanger to be easy to disassemble, inspect, clean and maintain. To ensure sanitary processing, our stainless steel product contact surfaces all have a food-grade finish of 32Ra or better, gaskets are chemical resistant and easy to replace, and product connections can be sanitary tri-clamp ferrules.

Since many of the exchangers that Enerquip designs for oil extraction processes are custom, there are a wide variety of styles, orientations and upgrade options available.

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Shell and tube condensers are safe, efficient and can be designed for much higher pressures and temperatures than other heat exchanger types. When stainless steel condensers are built to ASME pressure vessel code and TEMA standards for best fabrication processes, they can handle design pressures up to 3000 psig and temperatures from cryogenic up to 1000°F.

Keep reading to learn more about common applications and equipment for product extraction. Leave the calculations and design specifics to us.

Solvent Recovery Condensers

For solvent recovery, closed vapor recovery condenser systems provide a safe, environmentally friendly method for compressing vapors without emitting them into the atmosphere. This allows for the reuse of costly chemicals that would have otherwise been lost. Direct condensation of chemical and petroleum vapors using shell and tube heat exchangers can condense the vapors into a usable liquid, which can then be returned to the original source or repurposed.

To prevent fouling and scaling inside the tubes and bonnets, the surface finishes for condensers in the oil extraction market should be polished to a food-grade 32Ra or better. These condensers can be electropolished to a near mirror-like finish, like those commonly found in the pharmaceutical and personal care markets, to eliminate crevices that can hold material and lead to contamination.

Ethanol Coolers

The use of a shell and tube heat exchanger for ethanol cooling is an effective way to achieve temperatures well below zero. These coolers can be designed as single-pass or multi-pass units, with removable bonnets for easy inspection and cleaning of the tubes and other product contact surfaces. They can also be designed as U-tube exchangers with removable tube bundles. Thermal oil or liquid nitrogen is run through the shell side of the cooler, while the ethanol is run through the sanitary tube side.

Evaporators & Reboilers

After oil extraction using ethanol or hydrocarbons, there is a need to vaporize and recover the solvents from the product. An efficient way to perform this evaporation it to feed the product stream up through a vertical shell and tube heat exchanger, often called an external calandria or reboiler. This exchanger will typically have steam or hot thermal oil running through the shell of the unit, and the oil and solvent mix is fed upward through the tubes. As the steam or thermal oil heats the solution in the tubes, the solvents in the product flash off as vapor and exit the top of the exchanger to be condensed, while the remaining product is piped to the next step in the process.

Another type of evaporator used for this type of separation is a falling film evaporator, where the product mix flows down through the tubes instead of upward. Heating medium is provided in the shell side of the exchanger, and the vapors flash off as the product drips down the inside of the tubes.

Since oil and solvent mix, and their thermal properties can vary from case to case, design of evaporators is often performed by OEM’s that specialize in evaporation. Many of them have R&D test centers where products can be tested and thermal performance confirmed, in order to properly size the shell and tube exchanger used as the evaporator. Evaporators and reboilers are not easily scalable, and can have performance issues when flow is turned down, or if flow exceeds the tested rate. Because of this, it may be necessary to have multiple evaporators sized for different flow rates on different production lines.

Evaporators and reboilers used to remove solvents from product should have product contact surfaces polished to at least food grade 32Ra levels. Better finishes like those found in pharmaceutical applications can also be provided, typically 20Ra and electropolished. Because of these finish considerations, it is best to keep the product in the tube side of the exchanger, and utilize the shell side for utility streams.

Coolers & Chillers

Following the separation of solvents from the product, the organic vapors are sent to a condenser to recover them for re-use. The product also needs to be cooled down before it can be tested and packaged for distribution. A shell and tube cooler works well for this process.

The product can be fed through the tube side of the exchanger, which is sanitary and typically has at least a food-grade surface finish. The cooling utility is fed through the shell of the exchanger and is directed back and forth across the tubes by utilizing baffles, wiping away the heat from the product running inside of the tubes. This occurs safely without any mixing of the product in the tubes and the utility fluids in the shell. The sanitary stainless steel design of the shell and tube cooler also makes it easier to clean and inspect than coil type coolers or plate and frame coolers.

Typically the cooling utility is chilled water, a water and glycol mix, or thermal oil provided in a closed loop system from a refrigeration glycol chiller. These chiller units typically have user friendly controls that allow you to set a temperature point for the coolant, that is consistent with the design of the shell and tube exchanger. Your shell and tube exchanger designer should be able to calculate how much coolant is needed, and help determine an optimal inlet temperature for your glycol chiller, allowing for a typical 10°F rise in the coolant temperature.

Learn more about the advantages of including a shell and tube heat exchanger in your extraction process. 

Whether you’re in the research phase or the ready-to-buy phase, reach out. We can answer any questions along the way. 

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