Kitchen effluent containing grease, solids and water flows into the Big Dipper grease trap via an inlet. Solids enter first, which are then immediately captured by an internal strainer, whilst grease flows through the strainer basket underneath the inlet baffle and into the main tank. Due to the fact that FOG (fats, oils and grease) are less dense than water they rise to the surface of water within the Big Dipper tank. Water flows from the bottom of the tank into an outlet baffle and through into the main drain.
Incidental food solids less than 1” (25 mm) in diameter (W-250-AST) and 1.5” (38 mm) in diameter (W-750-AST & W-1250-AST) are separated and flushed out of the system automatically by the Automatic Solids Transfer component.These incidental solids are typical of those that are rinsed from plates before going to a dishwasher. It is important to note that the Eductor Pump of the AST is not designed to handle non-food products such as plastic, rubber or metal items.
The operation of the unit is conducted from the control panel at the top of the Big Dipper unit so you can manage the timings of the grease removal process. Different settings are available in normal operation mode, which periodically skim grease from the main tank. Sixty minutes before a skim cycle begins the heater will activate, this heats the contents of the tank and liquifies any grease to prepare for a skimming session. When a skim cycle begins, the skimming wheel will run through the grease so it sticks to the sides. The skimming wheel has an oleophilic coating that attracts grease and repels water, in order to improve the efficiency of FOG removal. The wiper blade then scrapes the grease from the skimming wheel, which then runs through the trough and into the grease collector. No single skim will last for a duration of more than sixty minutes, however in specific settings the Big Dipper will skim multiple times throughout the day to achieve the complete skim time indicated.
The grease collector and solid strainer basket can then be emptied on a daily basis or more frequently if necessary.