Recent content by zhangbd

I'm working with a supplier to upgrade the air handling unit of our fluid bed granulator, exiting inlet filter(F9) and exhaust filter(F9)will be replaced with HEPA, and fan will also be change accordingly, Question comes from supplier: to ensure the fan's performance, they said exhaust filter...

Very thanks to everyone for your concern, Colleagues from lab said this unkown white powder is aluminum oxide, so till to now, we can make a conclusion to this case, even though which has brought us so much trouble. It's caused by bad AHU designed, like ChasBean1 described above, the air...

Thanks very much, quark and tbrght: We have tried out every repair to indentify root cause: clean out the duct, change all of HEPA, and even check& clean all damps on duct, but the unkown white powder still blow out continually. is it zinc oxide? i think the high humudity air throgh the long...

Dear quark, Thanks for your concern, That HVAC is once through system, we are finding this powder on the floor,and also on the material bags, seems everywhere in the controlled area. The return points are at the floor level, and we conduct integrity test annually by third-party service. We are...

Hello, We're experiencing a serious non-conformance events that inspector has found out some unkown powder were blowing out of room vents, which dropped on the floor like floc, and it could be pressed and grinded into white powder by your fingers. Air is humidified and filtered(H14) after...

As far as I know, high moisture balls maybe be due to one or some reasons as below: 1: Jam of spraying nozzle result in un-balance solution spraying in chamber. 2: Insufficient powder also cause failure formation of particle. 3: Please check your inlet fan and chamber mesh, jam mesh also could...

Thanks SAK9 , but I couldn't open the link you gave. and you mentioned that double pipe exchanger, we also call it concentric tube exchanger, I think that would be a good solution to our problem. Dear greg87, Our existing distribution system pump purity water via a VDF pump, the setting...

Dear Daragh Did you mean the double-sheet exchanger? We have double-sheet exchangers installed in out purity water 80C and 20C production system, and I know why you plan to install a same one on your distribution loop, maybe that the ambient temperature is higher than 30C and with purpose of...

Dear cooky and SAK9: Yes you're right, I prefer to install a wrapping cooling jacket around the pipe to cool down the water temp. The diameter is DN40, and the peak temperature in summer is 35C. I have contacted some suppliers but they cannot provide us with this unit you mentioned, could you...

Dears, I have a problem with our 20C Purity water loop, in summer the water temperature of this loop is higher than 30C,under this temperature, you know, the risk of bio-fouling is high, however we don't want to install another exchanger to cooling the water temp. down, that would be a large...

Dear Daragh, Thanks very much for your kindly help and, you're right this drainer is a potential area bio-fouling. The existing U-shape section is to separate the tank side from outside, and the pressure inside actually is at ambient pressure due to another breather filter installed. Auditor's...

Our deionized water storage tank has a overflow drainer installed to avoid overflow when level switch fails, which is a U-shape PVC pipe leads to ambient, you know, generally, that's always one U-pipe full of water. However the question is that how and when do you know there is full of water in...

Dear All, There are some problem with our deionized water system pipe disinfectants selection: We just finished a deionized water system installation, you know, the pipe system is made by PVC pipe to connect the R/O unit, storage tank, Fixed bed demineralizers, Minxed bed demineralizers. Before...

Hi Bmoorthy, Thanks for your reply, and this HE is a type of double-sheet tubular heat exchanger with tube bundle of 80 pieces, at each end of the tube bundle there are two tube plate. The inner two of the tube plates are used for sealing off the shell, the two outer tube plates together with...

Dear All, Tubular heat exchanger in our plant we use to produce purified and process water(high temperature) for about 5years but, now condensate leakage is visible at the inner tube plate due to the failed sealing off between tube and plate. Because of the special running condition under which...