In standard eductors the drive pressure liquid discharges through a single nozzle to start the pumping action. The ejector doesnвЂ™t need electricity, only sufficient quantity of working substance.At the beginning, thereвЂ™s no need to fret over the differences thatВ the different is in the motive fluid:ДЄn ejector uses a gas phase motive, usually steam or air.ДЄn eductor uses a liquid phase motive, usually water.Д®ductors/Ejectors are liquid Jet pumps that use water or other liquids or gasВ under pressure to create a pumping action. The biggest advantage of the ejector is the lack of rotating parts as well as its construction simplicity. Pivotal dimensions are calculated from specified operating parameters of working and suctioned liquid. It is suitable to use the ejector at locations with sufficient working substance for device powering. parameters and the type of primary and secondary liquid. Selection of the design as well as the material of the body and suction nozzle of the ejector depends on operational and max. It can be made of plastic materials, too. Upon agreement, the injector can be made of special refractory steels and materials based on nickel titanium alloys, or tantalum. Mostly used materials are carbon or stainless steels. Suction nozzle can be manufactured by machining. The body of the ejector can be cast, machined from a forge, or it is welded from bent centring. Wafer type design has advantage of easy replacement of ejector in case of eventual modification of technological parameters as well as better access for servicing. The weld insertion in the pipe has advantages such as material and mass savings on the flanges as well as minimization of leakage at the flange joints. Then admixture of working and suctioned substance with the steady pressure and velocity profile leaves the ejector.Д®jectors can be produced in wafer as well as so-called welded-in designs. reduced velocity) as well as increase in liquid pressure was caused. At the inlet of the divergent section (expanding channel) there must be subcritical flow according to Huguenot theorem, so that compression (i.e. In case of subcritical flow, the mixing chamber has a shape of a cylinder and in case of supercritical flow it is tapered to slow down the flow. At the outlet of the suction chamber of the nozzle the admixture of substances has the same pressure but different velocity profile, that is to be conditioned in the mixing chamber. Thanks to that there is a negative pressure formed in the suction chamber and it begins to suck-in the secondary (driven) liquid. Due to expansion in the nozzle the pressure is dropped and the velocity of the primary liquid is increased. The ejector works on the principle that the working substance enters the suction nozzle, that can be either classical tapering or LavalвЂ™s one, downstream which there can be supercritical flow.

In that case the ejector releases mixture of two liquids.

According to type and state of driving and driven liquid, the ejectors are divided to water (water is both primary and secondary medium), gas, steam ones etc. For this reason, it is referred to as вЂњjet pumpвЂќ. Primary (working) liquid is its source of driving energy. It is similar to a pipe fitting and it has the same function as a pump. Ejector is a device whose task is to transport liquids through the pipeline.

Liquid ejector design calculation