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Exchange Column Sizing and Configuration


  7) How much DW-R™ resin do I need?

For columns treating B-100 with less than 1,000 parts per million (<0.1%) glycerin divide the B-100 flow in gallons per hour by three to get the gallons of DW-R™ resin required. Multiply gallons of DW-R™ times 6.7 to get the pounds of DW-R required.

For columns treating B-100 with more than 1,000 parts per million (>0.1%) glycerin divide B-100 flow in gallons per hour by 1.8 to get the gallons of DW-R™ required. Multiply gallons of DW-R™ times 6.7 to get the pounds of DW-R™ required.

  8) How deep should my bed of DW-R™ resin be?

A minimum of 30 inches of dry media is recommended.  Remember that the DW-R will swell to 2.25 times its dry depth when it becomes wet with glycerin and water.

  9) How tall should my exchange column be?

Allowing for doubling of the bed depth due to expansion, and 100 percent freeboard above the resin, the column should be a minimum of four times the bed depth. Columns that are too tall and narrow will be subject to greater stresses as the media swells.

  10) How should my strainers at the bottom of the bed be designed?

The laterals should have a screen mesh capable of filtering particle down to 125 microns. Strainers must be able to withstand pressures generated by the swelling of the media.

  11) What other design features should be considered in designing the exchange columns?

A top fill port configured to allow easy access for media replacement.

A bottom access door to allow for media removal and/or strainer repair or replacement.

An air vent at the top to allow air removal from the system.

Sight glasses in the side of the vessel for larger installations to allow for monitoring of the bed.

  12) How many columns do I need and how should my process flow be set up?

              We recommend two columns in series at a minimum. A third standby column is recommended for systems that will run continuously.  Having two columns in a series allows              the lag column to catch any contaminants that get through when the lead column is exhausted. This allows the lead column to be run to complete exhaustion. The lag column is then moved to the lead position. The standby column is then put into the lag position while the exhausted column that was in the lead position is rinsed with methanol to remove excess glycerin, or reloaded with fresh DW-R  media. Of course a well designed manifold makes this process go smoothly.

  13) What do I need to consider when handling DW-R™ Dry Wash Media?

As always, safety comes first!

Closely review the MSDS.

Insure that everyone wears PPE

Remember that the beads act like ball bearings on hard surfaces! Sweep up any spilled material immediately!

  14) How do I load DW-R™ in my exchange vessel?

Add clean biodiesel to the vessel until at least four inches covers the bottom strainer.

Add the resin slowly at first to avoid damaging the strainer at the bottom of the vessel.

After the proper quantity of resin is added, fill the vessel from the bottom slowly with B-100. Be sure to have a top vent open during this step. This approach will displace air from the bed.

Do not leave the DW-R™ exposed to air any longer than necessary. It will absorb humidity from the air.