Abstract: A drinking water distribution reservoir has a new draft tube mixing arrangement. An intermediate opening in the draft tube enables water to flow between the central passage of the draft tube and an intermediate portion of the tank. Directional walls can provided on the intermediate opening to help direct flow, and a check valve can be used to prevent flow from the intermediate section of the tank into the draft tube or prevent flow from the draft tube into the intermediate section of the tank. A venturi portion can also be provided on the draft tube to help draw water from the intermediate portion of the tank into the draft tube.

Abstract: A ClariCone-type clarifier is provided with a level sensor, a flow-condition detector, and a controller that work together for automatic control of a blow-down valve. The flow-condition detector detects a condition of the flow through the tank. The detector sends the input to the controller, which uses the input to determine a desired blow-down level. The level sensor detects the height of slurry in the tank, and the controller opens the valve when the slurry level reaches the level determined by the controller. The valve can be set to close after a predetermined fixed period of time, by a timer, or when the level sensor detects that the slurry level has fallen to a predetermined or calculated blow-down termination level.

Abstract: A ClariCone-type clarifier is provided with a level sensor, a flow-condition detector, and a controller that work together for automatic control of a blow-down valve. The flow-condition detector detects a condition of the flow through the tank. The detector sends the input to the controller, which uses the input to determine a desired blow-down level. The level sensor detects the height of slurry in the tank, and the controller opens the valve when the slurry level reaches the level determined by the controller. The valve can be set to close after a predetermined fixed period of time, by a timer, or when the level sensor detects that the slurry level has fallen to a predetermined or calculated blow-down termination level.

Abstract: A control system for an upflow clarification tank comprises a regulator for controlling one or more characteristics of the flow within the tank (such as the power, pressure, velocity, momentum, or velocity head of the flow), a sensor for measuring one or more of the characteristics of the flow, and a linkage that automatically adjusts the regulator to a desired setting based on the sensor measurement. A processor may be used to determine the desired setting for the regulator. The control system may also include structure enabling the operator to manually select between multiple methods for determining the desired setting.

Abstract: A control system for an upflow clarification tank comprises a regulator for controlling one or more characteristics of the flow within the tank (such as the power, pressure, velocity, momentum, or velocity head of the flow), a sensor for measuring one or more of the characteristics of the flow, and a linkage that automatically adjusts the regulator to a desired setting based on the sensor measurement. A processor may be used to determine the desired setting for the regulator. The control system may also include structure enabling the operator to manually select between multiple methods for determining the desired setting.