spray wash header design calculations
spray wash header design calculations
(OP)
I am designing a spray wash system for use underneath a belt filter. The system will have one inlet and go around the perimeter of the machine on three sides with an additional branch across the width of the machine in the center. It should look like a backwards E with the inlet on the top left corner. The machine is approximately 7' wide by 60' long, and the pipe will have flat fan spray nozzles aimed at the floor approximately every 2 feet. This results in 40 odd nozzles supplied by one inlet at about 30psig and 20GPM.
My question is about how to perform calculations to ensure that all nozzles will operate effectively. Do I need to do a pressure drop calculation between each nozzle adjusting for the flowrate as I go or is there some rule of thumb I can follow?
Thanks in advance.
Brandon
My question is about how to perform calculations to ensure that all nozzles will operate effectively. Do I need to do a pressure drop calculation between each nozzle adjusting for the flowrate as I go or is there some rule of thumb I can follow?
Thanks in advance.
Brandon
RE: spray wash header design calculations
I'd likely run 2" pipe for the first 10 nozzles or so, drop to 1 1/2" for the next 20 nozzles and then 1" for the last 10 nozzles. That should keep the dP through your header pretty low (less than a couple of psi) and keep the flows through each nozzle fairly constant. Of course, you could just run all 2" pipe also.
the difference in flow from one nozzle with 30 psi water supply pressure and the last one with 28 psi water pressure isn't that much (0.5 gpm versus 0.48 psi).
RE: spray wash header design calculations
Thanks!
Pete
RE: spray wash header design calculations
I am also concerned about the velocity in the pipe. With a 1.5" pipe (sch 40 galv.), I am only getting a linear velocity of 3.15fps, and with a 2" pipe, it is only 1.91fps. I know that typically, linear velocity should be between 5 and 12 fps. However, with 1" pipe or smaller I have the problem of too much drop through the pipe as well as an area smaller than the total area of the nozzles. There are 43 nozzles nominally 1/4" or 1/8" in size. I am not exactly sure how close the i.d. of the nozzle is to the nominal size, though I am checking into that. Any comments on the velocity issue and how to balance it with the sum of the nozzle areas? Thanks for all your help thus far.
Brandon
RE: spray wash header design calculations
RE: spray wash header design calculations
RE: spray wash header design calculations
I have just used it to design a system for spreading reuse water from a sewage plant over a vcery large area. I did the deign in less than a day. It paid for itself in time alone.
RE: spray wash header design calculations
THIS HAS WORKED ON STEEL PLANT.
I DONT KNOW WHERE IT CAME FROM SO I HAVE NO REFERANCES