Frequently Asked Questions (FAQ’s)

Why has the performance of my distillation unit changed?

• Several factors can affect the efficiency or throughput of a distillation unit, including reduced vacuum levels, higher solids in the waste stream, solids buildup inside the evaporator vessel, a dirty solvent tank, or deterioration of the oil jacket. If you need assistance, contact the PRI Service team and we’ll be glad to help diagnose and resolve the issue.

Why are vacuum systems used in certain distillation units?

• Vacuum systems are used to reduce the boiling temperature of solvents.  A vacuum level of -27″ hg can reduce the boiling temperature of certain solvents by up to 100 degrees F.

How often should I change the heat transfer oil?

• Reference the PRI Recommended Heat Transfer Oil change chart in your manual.  Your manual is located on disc and can be saved to your computer for easy reference.  If you need a replacement manual, please contact PRI.

How often should I perform preventative maintenance?

• Your operator manual has recommended maintenance schedules for your equipment.  PRI offers annual preventative maintenance service on all our equipment and can provide ongoing reminders for you to schedule service at a time that is most convenient for you.

What do I do when I need to order replacement parts?

• PRI maintains a comprehensive parts list for your equipment and has an extensive parts inventory at our facility.  Contact the PRI service team and we can provide a detailed price quote to ship you the parts you need.

When are the Operators and Maintenance personnel trained, and how often?

• Operator and Maintenance personnel are trained during the commissioning of a new system. Additional training should be performed any time new personnel is going to be operating the PRI equipment or as needed to update or refresh the training. The PRI Service Team can assist you in training your personnel.

How safe is my PRI equipment to operate?

• Safety is the primary focus of the design, engineering, and commissioning of our equipment. All our equipment is designed to be “fail safe” with several backup safety measures and alarms.  If you have a safety or hazard concern, please do not operate your PRI equipment until you have established a safe operational condition.  For questions or troubleshooting, please contact the PRI Service Team.

How do I clean my distillation unit?

• Cleaning should be performed regularly to maintain the optimal efficiency of your system. The cleaning procedures are explained in your PRI Owners Manual. Your manual is located on disc and can be saved to your computer for easy reference. If you need a replacement manual, please contact PRI.

What type of maintenance needs to be performed on a distillation unit?

• A distillation unit will work for many years with a minimum of maintenance.  The heat transfer oil should be checked annually and changed as required.  On scraped units, a visual inspection of the blade condition should be done annually.  Gaskets should be visually checked on a routine basis and replaced if necessary.  Vacuum pump strainers should be cleaned.

What type of permits will I need for the equipment?

• Appropriate local permits, including construction and necessary air permits.  Emissions from a distillation unit are very small and may not need a permit.  You do not need an EPA permit to recycle the solvents that you own firm produces at that facility.

Why should I have a unit with internal scraper blades?

• If your dirty solvent contains a high solids content, the scraped unit will prevent the solids from building on the side of the unit and reduce the heat transfer.  It will also make it easier to dump the still bottoms.

Isn’t distillation dangerous?

• Distillation is a properly designed unit for the solvent you wish to recover and is a very a safe process. Units are designed to meet all the applicable standards for the application and have many sensors and safety devices built in to prevent problems. Make sure all your equipment is designed to be installed and operated in a Class 1 Division 1 area.  PRI has thousands of units working in the field with an outstanding safety record.

I do not have a classified area in which to put a unit.  What alternatives can you offer?

• There are many options in this situation.  Units can be designed as outdoor installation or they can be built as self contained Class 1 , Division 1, or 2 enclosures.

Why should I have a sample of my solvent tested?

• The contaminant in a solvent may significantly affect the distillation characteristics .  Testing a sample in a lab situation will determine the distillation characteristics, what percent recovery can be expected, develop the operational set points of the unit, determine whether there are any problems with the still bottoms and be sure there is clean distillate recovered with no carry over.

Can I separate solvents through distillation?

• Partial or complete separation can be achieved depending on the particular solvents being used.  If high purity levels of distillate are required, enrichment towers ( fractionation columns ) can be used to achieve the desired results.

Can I separate water from solvents?

• Water can be separated dependent upon azeotrope binding  and binary distillation characteristics.  Resin adsorption can be used to further separate the water resulting in high degrees of solvent purity.  Membrane technology from Sulzer can also be used to separate solvents.

How much labor should I allocate per day to run a distillation system?

• Distillation can be a manual operation or fully automated.  A small system can be timer controlled and work to and from drums.  This type of system may involve an hour a day labor.  Larger systems can be fully automated and not require any labor on a routine basis.

I want to run a distillation system for only 8 hours per day.  Is this feasible?

• As with any piece of equipment, the smaller the unit and the more hours it operates, the more cost effective it will be.  A unit that only runs 8 hours per day may need to be greatly over-sized and very expensive compared to a unit that would be allowed to operate up to 24 hours per day.  PRI designs units to run unattended, 24 hours per day for some applications.

What do I do with the sludge leftover form the distillation process?

• Most sludge will be a liquid hazardous waste and need to be disposed of through a licensed hazardous waste service.  This type of service is readily available in all areas.  The least expensive waste to dispose of will be one that is pumpable and not solid.

Why can’t I just cook the sludge into a solid and then dispose of it in my trash?

• Regardless of how dry that sludge appears, the EPA has declared that if there once solvents in it, despite going through the distillation process, the sludge is assumed to contain those solvents and must be disposed of as hazardous waste.

Is it safe to allow distillation equipment to run unattended?

• There are multiple levels of sensors and safety equipment built into a system.  If any operating parameter falls out of its normal range, the equipment will safely shut down and indicate an alarm situation.

How to troubleshoot alarm situations?

• Systems that have text and graphic operator interface screens also have “help” screens available for each specific alarm condition.  These screens display the most common causes of a particular alarm that can be checked by an operator or maintenance personnel.  An alarm history is also maintained to allow supervisors to see a history of alarms.  NOTE: alarms are important, please do not reset them more than once.  If you are uncomfortable with an alarm state, please contact the PRI Service team.

How do I keep operators from changing the operating parameters?

• There are several levels of security available on systems.  Operators may have no, or limited authority to make changes.  Supervisors will have access to make changes to the operating parameters.

I can’t find the problem with my unit. Now what?

• Give our customer service department a call and describe the problem.  They maybe able to walk you through a troubleshooting process or may refer you to a field service technician for more advice.  Our customer service team members have many years of experience between them, and many have actually worked in the field.

Phone calls have not been able to fix the problem. Now what?

• PRI has a staff of full time Field Service Technicians.  Give us a call to have one of our expert technicians visit your site to troubleshoot and repair your unit.

Why do you ask so many questions? I just want a quote on a still.

• There are many factors that need to be taken into account to be sure that we understand what you want to accomplish, how it fits into your facility and the manner of operation.  A distillation unit should last 15 years or more so you need to be sure all factors are taken into account up front.

How do your units compare to a wiped film (thin film) evaporator?

• Wiped film (thin film for WFE) evaporators are designed to run in an application where there is continuous input from a manufacturing process and the composition of the input does not change significantly.  PRI’s units are designed to handle variable waste streams with little or no input from the operator.  Because PRI’s systems do not use high speed rotating parts and do not require tight tolerances , little maintenance is required compared to a wiped form unit.

Why do I need field service start up?

• A field service technician will commission the unit, determine operational profiles and parameters as well as train the personnel on the system’s operation and preventative maintenance procedures.  Training ensures the understanding of the system which improves safety, efficiency and service life.

How much can I reduce my waste solvent?

• Normally, you can expect recovery to be around 85-95 % of the available solvent.  This is dependent on the make up of the dirty solvent, the nature of the contamination and the condition/type of distillation unit.

Why don’t you offer turnkey installations?

• We are primarily an equipment manufacturer. There are several companies who specialize in equipment installations and have crews who do this as a living resulting in an inability to compete with local laborers that are more familiar with local codes, standards, and requirements.

What is the delivery time on equipment?

• It all depends on the activity in our engineering department and shop status.  Some equipment is easier to build than others and some designs are more standard than others.

Can I get a list of references?

• Yes, we have extensive lists of many industries and clients that we have worked with and we can provide that upon your request.