Hybrid Ejectors - Ejector and Pump Combination System

Vacuum is necessary during various steps of edible / vegetable oil and food processing. These steps essentially include hydrogenation, fractionation, bleaching, deodorization and deacidification. Out of all vacuum equipments, Ejector Vacuum System has established the superiority and versatility of their use as compared to mechanical vacuum pumps. The most outstanding advantage of the Steam Jet Ejector is total absence of moving parts which eliminate mechanical breakdown, and assures constant and dependable operation with freedom from repairs. No adjustment or lubrication is required nor are any specially trained operator necessary as their operation is very simple. Over and above, Steam Jet Ejector Vacuum System convey at very high velocity which are many times the speed of sound, they are capable f handling large volume under vacuum thus making them eminently suitable for deodorization application wherein high quality of open / sparging steam has to be handled.

Based on the process requirement, a Multi Nozzle Ejectors can be designed five or seven nozzles type. Generally, one nozzle in the centre and remaining four or six nozzles are evenly circled around it. Multi Nozzle Ejectors can reduce the steam consumption by 15% to 20% as compared to Single Nozzle Ejectors when designed for the same conditions and it is more efficient to single nozzle ejectors. At times it is also considerably shorter in length when compared with same rated single nozzle ejectors.

The efficiency of a Steam turbine is mainly determined by the pressure of the steam at its outlet. The Turbine Surface Condenser is therefore maintained under vacuum. To enable this, the Steam Jet Ejector Vacuum System must be capable of removing all non condensable and associated water vapour from the Surface Condenser to produce the minimum steam condensing pressure consistent with physical dimensions and heat transfer and to provide for deaeration of the condensate. The sources of non condensables include air leakage through all system components operating below atmospheric pressure, gases released from feedwater drains and vents admitted to the condenser, gases released for makeup admitted to the condenser, condensate surge tank when utilized in a closed cycle and disassociation of feedwater into oxygen, hydrogen and non condensables.

Three Stage Ejector is similar in construction as of Single Stage Ejector, but having intermediate condensers. Three Stage Ejector comprises of Booster Ejector, Booster condenser and a Two Stage Ejector. And Two Stage Ejector consists of a high vacuum ejector, a inter condenser and a low vacuum ejector. This system will give higher vacuum and can handles larger quantity of condensable vapors. Gas or Gas vapor mixture is discharged from the first stage into the condenser where the operating steam is condensed and gases are cooled. The cooled gases are then entrained by the second stage and discharged into the second inter condenser. Here, the steam used in the second stage is condensed. The gases are finally entrained by the third stage and discharged to atmosphere.