The TRI-MIX warm-mix injection system from Tarmac International Inc., Lee’s Summit, Mo., is designed for dual use—the producer can set it up for water or chemical injection to create foamed liquid asphalt cement (AC) at lower production temperatures than hot-mix asphalt. Here’s how it works.
First, the operator sets the percentage of injected liquid into the controls, which will follow the production rate of the plant.
The variable frequency driven pump then delivers the liquid from the pump skid to the dual injection nozzles inserted on opposite sides of the static mixer. (The static mixer is located in the AC line before the entry into the drum mixer or pugmill.) The high pressure liquid spraying into the static mixer on opposite sides of the AC line provides full agitation for foaming the liquid AC to approximately 10 times its normal volume.
Three spiral flights located in the downstream nozzle section further mix the injected liquid and AC to make the foamed AC.
Once the AC is foamed, it continues down the existing AC pipe to enter the drum in the mixing area to coat the aggregate. When the liquid spray is not in use, the 40 psi compressed air supply is provided through the hose to the nozzles to prevent the AC from backing up into the system and clogging the injection nozzles and hose.
For more information, contact Tarmac’s sales team at (816) 220-0700.