Diffuser (sewage)

About: Diffuser (sewage) is a research topic. Over the lifetime, 6487 publications have been published within this topic receiving 40404 citations.

Submergible centrifugal pump having improved diffuser bushings

Abstract: A submergible, centrifugal pump utilizes an improved bushing system for absorbing downthrust at each stage of the pump. The centrifugal pump is a multi-stage pump having a plurality of impellers keyed to a rotatable shaft. Diffusers cooperate with the impellers to conduct the pumped fluid upwardly from one impeller to the next. The improved support system comprises simple diffuser bushings that are generally cylindrical in shape, and relatively inexpensive to manufacture. Each diffuser bushing is disposed between a diffuser and the next upwardly sequential impeller to support that impeller with respect to the downthrust created during pumping.

Compost tea system

Abstract: A compost tea system uses a water-holding tank for containing process water. Compost is immersed into the water in the tank in baskets defining a filter media. Air is pumped into membrane disk diffuser modules in the tank and the liquid is sparged with fine bubbles to thoroughly agitate the liquid, extract nutrients and microorganisms from the compost, and to ensure a high concentration of dissolved oxygen in the liquid. The high level of oxygen selects for desired aerobic organisms to produce a rich compost tea. The finished tea is drained out of the tank and the tank and its components are easily cleaned and sanitized.

The Box Method: a Practical Procedure for Introduction of an Air Terminal Device in CFD Calculation

Abstract: The Box Method a Practical Procedure for Introduction of an Air Terminal Device in CFD Calculation by Peter V. Nielsen Aalborg University The velocity level in a room ventilated by jet ventilation is strongly influenced by the supply conditions. The momentuni flow in the supply jets controls the air movement in the room and , th~refore, it is very important that the inlet conditions and the numerical method can generate a satisfactory descriptign of this momentum flow. The Box Method is a practical method for the description of an Air Terminal Device which will save grid points and ensure the right level of the momentum flow. Introduction Figure I shO\~/s the decay of the maximum velocity in the flow that runs along the ceiling in a room with two-dimensional recirculating air movement. The velocity level obtained by two different inlet conditions, corresponding to two different supply openings, is retained in the flow along the ceiling. The differenc~ in the velocity level will be retained in the occupied zone as well. A satisfactory description of the inlet conditions is, therefore, very important for the prediction of the flow in the whole room . Figure I also shows that the velocity decay below the ceiling corresponds to the conditions in a wall jet, except close to the end wall opposite the supply opening. This means that the air movement below the ceiling can be expressed by parabolic equations, although the flow as a whole is recirculating and , therefore, described by elliptic equations. This strong upstream influence in the first part of the flow is the background for the wall jet description of boundary conditions for supply openings discussed in this paper. The momentum flow in the wall jet below the ceiling controls the air movement in . ~ room. For example, the maximum velocity in the occupied zone is proportional to the inlet velocity multiplied by the square root of the supply area, which expresses the square root of the supply momentum flow. Therefore, it is very important that the inlet conditions and the numerical method produce a satisfactory description of the momentum flow . The supply momentum flow from diffusers depends on small details in the design. This means that a numerical prediction method should be able to handle small details in the order of a few millimetres to room dimensions of many metres. This wide range of geometry necessitates the use of many grid points and demands, therefore, a large computer or a procedure which can reduce the number of grid points.