The Ultrafoam GX™ Process
One of the most economical and environmentally friendly techniques
is to introduce some water into the process to cause the AC to
foam. The foaming results when the hot AC contacts the water causing
conversion to a steam while being contained within the asphalt
cement in the form of small bubbles. The process of foaming aids
in uniform distribution of the AC across the aggregate surfaces
to obtain maximum coating and temporarily lower the AC viscosity,
improving the coating and workability of the mixture at lower
temperatures. To hold the steam in the AC foam, the AC must retain
enough viscosity and cohesiveness to encapsulate the steam, requiring
the appropriate injection water to AC ratio. Warm mix can lower
emissions, improve quality, and lower costs in four major areas:
- Reduce the emissions of volatile hydrocarbons.
- Eliminate objectionable odors.
- Diminish asphalt cement oxidation during production.
- Reduce fuel consumption.
Gencor has devised a simple, robust, and reliable method to inject steam into the foaming process, using only the energy of the pump or head supplying the AC and water. The Ultrafoam GX™ can achieve consistent foaming at varying production rates without the use of a powered mixing device. As a result, the AC and water can be introduced at widely different flow rates, temperatures, and pressures.
The Ultrafoam GX’s™ patent pending design provides variable orifices for both AC and water and a means to keep the two flows in intimate contact so that the available mixing energy is used efficiently. While the Ultrafoam GX™ can be used with any two fluids, it is especially valuable when used with two liquids where one is a very small percentage of the second, as with warm mix asphalt production. It is also especially valuable when one of the liquids changes to a gas, producing a foam mixture.
When making foamed asphalt, a small percentage (one to two percent by weight) of water is injected into the center of the AC flow. The Ultrafoam GX™ design has a centrally located spring loaded water valve that will open when the pressure of the water is impressed behind the valve. External to the centrally located nozzle is a unique design diaphragm plate which provides a means to introduce and direct the flow of AC to the process. This unique diaphragm allows the AC to flow through at varying rates while keeping a constant fluid pressure. As the flow of the AC is increased, the fingers of the diaphragm will deflect allowing for increased flow area. Equally important is that the flow stream of the AC is directed toward the center nozzle such that the AC flow converges to the center of the injection point of the water. Due to this unique patent pending design, the Ultrafoam GX™ maintains the perfect ratio of AC and water at all production rates and creates smaller more stable bubbles for even, consistent asphalt foaming.
Advantages:
- Mixes AC and water together in a proportionate and continuous fashion.
- Good foaming at all production rates.
- No loss of pressure drop and mixing energy.
- Generates evenly sized bubbles.
- Improves workability of the mix.
- All of the mixing energy is provided by the pumping system.
- Simple and reliable.
In addition, the Ultrafoam GX™ provides several other important features.
- Water sealing:
- Foam expansion:
- Clearing of AC flow line:
The special valve design prevents the AC from back-flowing into the water piping system.
The foaming action causes a significant expansion in the foamed AC. The design of the device allows for a substantially smaller flow area for the normal AC materials with a greatly expanded flow area for foamed AC.
The Ultrafoam GX™ can deflect either upstream or downstream AC and therefore when not running production, the AC lines can be cleaned by reversing the pump.