farahnaz77:
I've only heard of two instances where an engineer took to designing and building his own ejector. Both ended in failure. This is understandable, since a lot of the technology is locked up by the existing manufacturers who have spent a lot of time and money in developing their designs.
With proven designs available, why would you feel pressed to design, test, modify, and install your own personal design? Are you limited in being able to buy an existing, proven & warranted design?
What you are proposing is not the conventional case since you yourself admit you know little or nothing of designing such a unit. It is obvious that someone (you or your supervisors) will have to take the risk and gamble of seeing to it that your design works as per specified needs. This is not done in conventional engineering circles. Professional and experienced suppliers are called upon to furnish proven and warranted products.
I have done what you propose by buying a catalog listed unit from Penberthy. Depending on the capacity, it should be very low cost. I hope this experience helps.
Art Montemayor
Spring, TX