Oil Collection Pumps for Biodiesel
By Rick Da Tech
Pumping oil seems to be the way many get started. Each style of pump and motor will have unique advantages based on the unique properties of each. Which pump and motor you choose will depend on your needs and situation.
- Vane Pumps
- Gear Pumps
- Centrifugal Pumps
Types of Motors:
- A/C Motors
- D/C Motors
- Engine Motors
Vane Pumps are a class of pumps that either use sliding vanes or flex vanes. The sliding vane pumps are very often used in the cheap hand drum pumps. They are cylinders with an offset shaft slotted to accept the sliding vanes. The vanes slide in and out of the slotted shaft to keep contact with the outer cylinder. This creates pockets that capture the oil and move it from input to output. They are not really suitable for extended use pumping WVO. They have a lot of resistance to turning and low flow rates. A hand crank drum pump of this style will be a real workout to move a full drum of WVO.
A flex vane pump also has a cylinder with an offset shaft. In this case the vanes are flexible. This is the type commonly used on the inexpensive pony pumps and marine pumps that have a small motor attached. They have low flow rates and often have underpowered and unprotected motors running them.
This $39.00 stainless steel marine pump from Harbor Freight is an example of a vane pump. WVO is generally too viscous for these pumps and the rubber impeller often separates from the shaft. This style of pump is not really appropriate for pumping WVO except on a small scale in an emergency. If you flush the pump with water after use, they will usually last longer. A lot of WVO collectors have one of these style pumps lying around dead.
Gear pumps are great but will not tolerate contaminates and will seize up if they pick up something hard. As transfer pumps of clean oil they can’t be beat. The oil pump in your engine is an example of a gear pump. There have been a few people that have turned engine oil pumps into WVO collection pumps. Some machining is required for that conversion, but you wind up with a good pump for clean WVO.
Good gear pumps tend to be more expensive than other types of pumps. The Fill-Rite 1604 is an example of this style of pump. A lot of people use this pump exclusively for pumping WVO. It will pump a drum of WVO in about 15 to 20 minutes.
Redlinepumps.com makes WVO collection pumps based on the Chevy oil pump. They are a little more expensive than the Fill-Rite. They also do a good job of collecting oil. They are available without the motor or with AC or DC motors.
JOAT on infopop broke the handle off his hand crank gear pump so he mounted a drill on it. He collected 2000 gallons of WVO using it before he moved on to another system.
This pump style is a good option for those that don’t have a lot of oil to load onto the truck or that move the oil to smaller lighter containers to load into the trunk of your car. They are affordable and rugged but a little on the slow side. They can usually handle the semi-solid slushy oils, but not oil that is frozen solid.
Centrifugal pumps operate by pushing fluids from the center of a spinning impeller out to the edge. They need to be primed but can be operated by any style of motor. They are limited to 10% solids with a maximum particle size of ¼ the diameter of the ports. They perform well on oil but not slushy oil or solidified grease.
This little 1" water pump from Northern Tool is a good example of a centrifugal pump used for WVO collections. It is light weigh and portable and can handle liquid oils with no problem.
Trash pumps are a special type of centrifugal pump designed specifically to handle more solids making them better for WVO collections than the standard centrifugal pumps. They can handle solids up to ½ the diameter of the ports and up to 25% solids. They do very well with all WVO except the stuff that’s frozen solid. These types of pumps have high power requirements making them more expensive than the standard centrifugal pumps. In most cases they have gasoline or diesel powered engines attached to them making them heavy. Make sure you either have a strong person holding the discharge or connect it directly to the tank. Holding on to the discharge line of one of these is like holding onto a fire hose. If it gets away, your looking at twenty to thirty gallons of WVO sprayed everywhere before you can shut the pump down.
These are some of the best pumps available for serious WVO collections. With a 2” trash pump you can drain a drum in a few minutes. Prices start at about $500 and go up.
A/C (alternating current) motors use regular household power to run them. They are cheap, powerful, and cost effective. They are great at the shop, but not so great on the collection site. You need A/C power to operate it. Most restaurants do not have an electrical outlet outside and you would need to run an extension cord inside the restaurant. This can distract the restaurant workers, cause a safety hazard (tripping on the cord) and track crap onto the clean floors at the restaurant.
D/C (Direct Current) motors are battery operated. The ones we are interested in are all 12V and operate on the same voltage as your car or truck. Many people will have a battery, a pump, and hoses all mounted on a two-wheeled dolly to make collections easier. Often people collecting from drums using this setup will pump into 5 gallon or smaller containers taking only the clear oil from the top and load it in the trunk of the car. Some will pump into a small 10 or 20 gallon tank sitting in the trunk. Marine deep cycle batteries are best for this application.
This Dixon 12V pump is made of aluminum to reduce the weight and would make a great pump for collections but would need to be directly connected to the vehicle due to it’s high power draw.
For people without trucks that can’t get the restaurant to put the oil into smaller containers, a DC motor on a gear pump will provide excellent service for collections. Just make sure the DC motor has sufficient duty cycle to withstand 30 minutes of continuous duty and has a thermal switch to protect the motor from overheating. There are some pumps out there like the Fill-Rite 1604 or the Redline that can handle the job.
If you have a trash pump, you will be using one powered by a gasoline or diesel engine. Some centrifugal (water) pumps are available with small lightweight engines, but most are heavy enough that you would want to use a dolly to move it around.