A method for filtering a gas includes passing a gas into a compartment of a casing that includes a polymeric film, the casing having: a first sleeve having a first outlet opening, a first filter being at least partially disposed within the first sleeve so that gas passing through the first sleeve must pass through the first filter; and a second sleeve having an second outlet opening, a second filter being at least partially disposed within the second sleeve so that gas passing through the second sleeve must pass through the second filter, the second sleeve being closed so that the gas passing into the compartment of the casing passes through the first sleeve and the first filter and directly contacts at least a portion of the first sleeve comprised of the polymeric film but does not pass through the second sleeve. Opening the second sleeve when a predetermined condition is met so that the gas passes through the second sleeve and the second filter.

A fine bubble generating apparatus has a storage tank, a liquid feeding unit suctioning and feeding liquid stored in the storage tank, a gas discharge unit discharging gas into the liquid which is being fed by the liquid feeding unit, and a storage tank. The gas discharge unit includes a gas discharge member with pores having pore diameters of 1.5 m or less, and a base member having a groove formed in a surface contacting the gas discharge surface of the gas discharge member. The liquid feeding unit moves the liquid along the gas discharge surface of the gas discharge member by causing the liquid to flow in a flow channel enclosed by the gas discharge surface of the gas discharge member and the groove of the base member such that a velocity relative to the gas discharge member is not less than 1 msec.

Fine-bubble-producing aeration units and large-bubble-producing (or other mechanical) mixing units are interspersed with each other in a given body of water to be treated. The two different types of units are independently controlled to independently regulate degrees of aeration and mixing in the given body of water.

A bag assembly for use with a heat exchanger includes a flexible bag having of one or more sheets of polymeric material, the bag having a first end that bounds a first compartment and an opposing second end that bounds a second compartment, a support structure being disposed between the first compartment and the second compartment so that the first compartment is separated and isolated from the second compartment. A first inlet port, a first outlet port, and a first drain port are coupled with the flexible bag so as to communicate with the first compartment. A second inlet port, a second outlet port, and a second drain port are coupled with the flexible bag so as to communicate with the second compartment.

A method of air scouring an immersed membrane is described in this specification. The method comprises a step of adjusting one or more aeration parameters during a permeation cycle, or between a permeation cycle and a back pulse or relaxation cycle, or between successive cycles. The method may be used with a gas delivery device described in this specification in which a supply of gas is provided to a manifold with multiple ports connected to multiple conduits. The method may further comprise bringing a flow of pressurized gas into a tank to near or below the bottom of a membrane module. At about this elevation, the flow of pressurized gas is split into multiple flows of pressurized gas. Each of the multiple flows of pressurized gas is directed to a different lateral position and then released as bubbles.

An airlift, water mixing system that passes biocides, algaecides and gas through a ship's ballast water tanks and its pipping to control water PH. Vertically moving diffusion grids provide air sparging in treated ballast water that accommodates variances in ballast water levels without changes in pressure or power used by an air compressor connected to a diffusion grid.

A filter assembly includes a casing having of a polymeric film and bounding a compartment, the casing having an inlet opening communicating with the compartment and a first outlet opening communicating with the compartment. A first filter includes a porous filter body through which gas can pass and has a pore size smaller than 1 m, the first filter being coupled with the casing so that the filter body is at least partially disposed within compartment of the casing and so that gas passing through the compartment of the casing from the inlet opening to the first outlet opening must pass through the filter body.

The present invention is directed to a process for producing precipitated calcium carbonate with improved resistance to structural breakdown, wherein the milk of lime is carbonated in the presence of at least one gas other than carbon dioxide, or the carbonation is carried out in the presence of a static gas bubble comminution unit as well as to precipitated calcium carbonate obtained by such a process.

Jet fuels' thermal oxidation characteristics are evaluated via the Standard Test Method for Thermal Stability of Aviation Turbine Fuels. This test method mimics the thermal stress conditions encountered by jet fuel in operation and is often carried out by laboratory devices, known as rigs. The rigs include a test section having a sleeve and a heater tube arranged therein. A pair of bus bars secure the test section to the rig and apply a current to the heater tube. The applied current heats the heater tube and subjects the sample jet fuels that are flowing in the volume between the sleeve and heater tube to high temperatures, which may produce thermal oxidation deposits on the heater tube. Heater tubes are difficult to install, however, and a gauge may be used to ensure accurate placement of the heater tube within the sleeve. In addition, the fuel sample must be prepared via an aeration process, and systems are disclosed for automating the aeration process such that the sample is prepared precisely according to the test standard. Moreover, the rig includes a pump system that moves the fuel sample through the test section, and a pump system is provided in a double syringe arrangement that optimizes fuel flow through the test section without fluctuation. Finally, the rigs include cooling systems for cooling the bus bars and maintaining an appropriate thermal profile within the heater tube, and cooling systems may be provided that independently control the temperature of each bus bar.

A treatment plant and method for controlling a treatment plant suitable for treatment of wastewater. The treatment plant includes a circulation channel housing liquid, a submersible flow generating machine arranged in the circulation channel and generating a liquid flow along the circulation channel, and a control unit that is operatively connected to the flow generating machine. The flow generating machine is driven in operation by the control unit. The method includes the steps of: driving the flow generating machine at a nominal speed, decreasing the rotational speed of the flow generating machine from the set nominal speed, detecting the rotational speed at which the torque of the flow generating machine is equal to a predetermined threshold, and determining the flow velocity of the liquid at the flow generating machine based on a predetermined relationship between the rotational speed of the flow generating machine and the flow velocity of the liquid.