11 replies to this topic

[farid.k]

Hye there. I have 1 question. Anyone has example pump that can tolerate running dry condition? I've communicated with one of the pd pump supplier, they said his pd pump can tolerate running dry condition but they didn't recommend it.

Our requirement is to empty out the reactor as per current practise which is they pump out completely.

Definitely centrifugal pump is not a good choice. Any suggestion? I.e. blackmere, viking etc for typical rotary pump

[Saml]

In my experience, some sliding vane Blackmer pumps and double diaphragm like the Sand Pipers are able to  tolerate some abuse by running them dry for a few minutes.

Your vendor is right. The pumps can "tolerate" running dry. Hover they cannot tell you to run it dry as a "normal condition". If the operator forgets the pump for an entire shift, the next shift will probably find it broken.

[farid.k]

Saml:

 

Yea agreed with you sir.  I just afraid if operator compiled say maintain run dry for 3 minutes for every shift but after one year kaput due to too frequent.  Then need to change new.  They have scavenger pump that design for run dry but i am not sure the type/brand

[Saml]

I see that your needs are not what I had in mind. I was thinking on a continous process reactor that needed to be drained once in a while. You seems to be talking about a batch operation that happens once a shift.

 

My experience is with the use of the pumps I mentioned as "portable" pumps for sporadic use.

[breizh]

Hi farid,

Can you pressurize your reactor to empty it totally? It's what I get used to see for batch process .

 

Breizh

Edited by breizh, 23 December 2017 - 03:29 AM.

[farid.k]

Hi farid,
Can you pressurize your reactor to empty it totally? It's what I get used to see for batch process .

Breizh

Yes. Maybe i can consider that. On top of reactor has N2 supply.
Just that The modification should remain same operating manual.

[Zauberberg]

Check peristaltic pumps. They are the most likely candidate if flow is reasonably small. Make sure you test the pump hose compatibility with the pumped fluid. Otherwise the hose gets dissolved in a few hours at best.

[farid.k]

Check peristaltic pumps. They are the most likely candidate if flow is reasonably small. Make sure you test the pump hose compatibility with the pumped fluid. Otherwise the hose gets dissolved in a few hours at best.

Thanks sir for the reply. Can i know what is typical brand that can handle big flow i.e. 45m3/h? Normally they prefer to use api compliance pump.

[Zauberberg]

http://www.flowrox.c...ion_11-2017.pdf

[breizh]

Farid,

Another Brand :PCM delasco .

 

Note : make sure about the compatibility of the material with your product to echoe Zauberberg !

 

Breizh

[Na3BrO]

If pulsation on flow is okay, a 3" diaphragm pump can be operated dry (pulling air or just vacuum) for almost any length of time. Large peristaltic pumps (or hose pumps, as they are sometimes called when large) are hard to find.

 

Running any kind of pump that requires lubrication/cooling from the pumped fluid may not provide adequate life. Rotary vane/gear pumps may be okay for the services, provided the pumped fluid provides enough lubricity to stay coated on the gears even when run dry. You still would not want to run them dry for too long, as the seals would tend to overheat.

 

Diaphragm pumps can be run dry indefinitely, and are commonly used to pump out reactors in industries like the polymer industry. Temperature limitations are a concern, however.

 

Edit: Also note that if certainty of containment is required due to the hazard of the pumped fluid, diaphragm pumps are not the best choice. Diaphragm failures lead to loss of containment on these designs.

Edited by Na3BrO, 10 April 2018 - 04:00 PM.

[farid.k]

Thanks all for the reply..