Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: Pump for condenser and aspirator
Jerbanzo bean
Harmless
*




Posts: 4
Registered: 28-3-2017
Member Is Offline

Mood: No Mood

[*] posted on 28-3-2017 at 23:14
Pump for condenser and aspirator


Hi, I've been running my 400mm condenser with a real cheap submersible aquarium pump. It got the job done perfectly fine but recently kicked the bucket :( I also sometimes use a water aspirator.

To save on my water bill I was wondering if I could just run a strong enough pump through my aspirator. If I can, I could get a little valve to lower the pressure when I'm using the pump for my condenser. Has anyone has any experience using a pump for their water aspirator?

Bonus question; do you think I could use both at the same time with a splitter after the aspirator? I think there might be a way to get just enough pressure to use both and not have too much pressure after the aspirator to mess with the vacuum. Just guessing here :P
View user's profile View All Posts By User
JJay
International Hazard
*****




Posts: 3440
Registered: 15-10-2015
Member Is Offline


[*] posted on 29-3-2017 at 01:46


I've done that before with tap water, but I definitely prefer to use a tap and a pump or perhaps two pumps. You want pretty high water pressure for a high vacuum; while your aspirator may start functioning at well below 15 psig, to pull the most effective vacuum, you want much higher water pressure, and it can be scary running that kind of pressure through your condenser.



View user's profile View All Posts By User
XeonTheMGPony
International Hazard
*****




Posts: 1640
Registered: 5-1-2016
Member Is Offline

Mood: No Mood

[*] posted on 29-3-2017 at 04:17


Well you can providing the pump is large enough and can handle the flow and pressure (You can find this info on the pumps head curve)

When controlling pressure ideally you never want to dead head the pump so you bleed pressure by diverting valve, this diverter can feed the condenser, Alt: You can have two diverter valves to independently control pressure and flow through the condenser.

from here it gets complex with buffer tanks to remove pulsations from diaphragm pumps and pressure regulating valves.

------Condenser----Pressure
----------^--------------Bleed
----------^-------------^
------- Valve---------Valve
Pump > ^-------------^----> Aspirator

Simpler if possible is a 3 way diverter valve as it will automatically balance when you want more condenser flow Vs more pressure bleed off.

Alt:

--------------------------------Condenser
----------------------------------------^
----------------------------------Globe valve
----------------------------------------^
---------------------------------------PRV
Pressure pump > Buffer tank >--^---> Globe valve > Aspirator


[Edited on 29-3-2017 by XeonTheMGPony]

[Edited on 29-3-2017 by XeonTheMGPony]
View user's profile View All Posts By User
Sulaiman
International Hazard
*****




Posts: 3695
Registered: 8-2-2015
Location: 3rd rock from the sun
Member Is Online


[*] posted on 29-3-2017 at 04:31


I have been using a 5 way valve (intended for aquarium air supply) for vacuum,
so must be good for water I guess.
cheap e.g. http://www.ebay.co.uk/itm/1-2-3-4-5-Way-Air-Flow-Distributor...




CAUTION : Hobby Chemist, not Professional or even Amateur
View user's profile View All Posts By User
XeonTheMGPony
International Hazard
*****




Posts: 1640
Registered: 5-1-2016
Member Is Offline

Mood: No Mood

[*] posted on 29-3-2017 at 04:45


Quote: Originally posted by Sulaiman  
I have been using a 5 way valve (intended for aquarium air supply) for vacuum,
so must be good for water I guess.
cheap e.g. http://www.ebay.co.uk/itm/1-2-3-4-5-Way-Air-Flow-Distributor...


Sadly not even close for the volume of flow, remember water is 800 times more dense then air this friction losses amount to a huge number in such manifolds, globe valves are required as they where built for throttling so provide smooth adjustments, ball valves get eaten up from cavitation erosion over time.

All the pump lines should be 1/2 as with the valves and only bush down to where the tube connect

But for low flow systems those are a nice looking valve! be good for air supply setups for the lab
View user's profile View All Posts By User
Jerbanzo bean
Harmless
*




Posts: 4
Registered: 28-3-2017
Member Is Offline

Mood: No Mood

[*] posted on 29-3-2017 at 06:02


Quote: Originally posted by XeonTheMGPony  
Well you can providing the pump is large enough and can handle the flow and pressure (You can find this info on the pumps head curve)

When controlling pressure ideally you never want to dead head the pump so you bleed pressure by diverting valve, this diverter can feed the condenser, Alt: You can have two diverter valves to independently control pressure and flow through the condenser.

from here it gets complex with buffer tanks to remove pulsations from diaphragm pumps and pressure regulating valves.

------Condenser----Pressure
----------^--------------Bleed
----------^-------------^
------- Valve---------Valve
Pump > ^-------------^----> Aspirator

Simpler if possible is a 3 way diverter valve as it will automatically balance when you want more condenser flow Vs more pressure bleed off.

Alt:

--------------------------------Condenser
----------------------------------------^
----------------------------------Globe valve
----------------------------------------^
---------------------------------------PRV
Pressure pump > Buffer tank >--^---> Globe valve > Aspirator


[Edited on 29-3-2017 by XeonTheMGPony]

[Edited on 29-3-2017 by XeonTheMGPony]


Hmm yes this does look good. I like your solution with the buffet tank especially.
View user's profile View All Posts By User
Jerbanzo bean
Harmless
*




Posts: 4
Registered: 28-3-2017
Member Is Offline

Mood: No Mood

[*] posted on 29-3-2017 at 06:05


Quote: Originally posted by JJay  
I've done that before with tap water, but I definitely prefer to use a tap and a pump or perhaps two pumps. You want pretty high water pressure for a high vacuum; while your aspirator may start functioning at well below 15 psig, to pull the most effective vacuum, you want much higher water pressure, and it can be scary running that kind of pressure through your condenser.


A buddy of mine does odd jobs. He scraps a lot of HVAC equipment and told me he could get me a condenser out of a fridge or dehumidifier pretty easily. I might just start on the condenser to vacuum project I've been planning out and buy another cheap aquarium pump.

Might be cheaper over all and most likely more effective and a longer lasting solution.
View user's profile View All Posts By User
XeonTheMGPony
International Hazard
*****




Posts: 1640
Registered: 5-1-2016
Member Is Offline

Mood: No Mood

[*] posted on 29-3-2017 at 10:58


a refrigerant condenser is a gas to gas exchanger, with care full cleaning you can us them as a gas to water Hx but being copper and aluminium not sure what you can do chem wise with it.

Less you're going to use it as a heat rejection source for your water after the glass condenser int he lab, but then you need an isolated circuit! As any corrosive gasses absorbed into the water from the aspirator will make fast work of the riffled copper tubing! (Lots of surface area!)
View user's profile View All Posts By User
Jerbanzo bean
Harmless
*




Posts: 4
Registered: 28-3-2017
Member Is Offline

Mood: No Mood

[*] posted on 30-3-2017 at 14:43


Quote: Originally posted by XeonTheMGPony  
a refrigerant condenser is a gas to gas exchanger, with care full cleaning you can us them as a gas to water Hx but being copper and aluminium not sure what you can do chem wise with it.

Less you're going to use it as a heat rejection source for your water after the glass condenser int he lab, but then you need an isolated circuit! As any corrosive gasses absorbed into the water from the aspirator will make fast work of the riffled copper tubing! (Lots of surface area!)


I'm actually going to just pull a vacuum with the condenser rather than use my aspirator. I think it would hold up for a while, but yes I'll probably damage it with anything corrosive that ends up not getting trapped in my condenser.
View user's profile View All Posts By User
XeonTheMGPony
International Hazard
*****




Posts: 1640
Registered: 5-1-2016
Member Is Offline

Mood: No Mood

[*] posted on 30-3-2017 at 18:21


How on earth do you do that with a coil of copper?!

All cooling systems using the Carnot cycle have an evaporating coil, a metering device, a compressor and a condensing coil.

I can not think of any way you'd make any vacuum using a coil of fined copper, so I'll go on a limb and guess you mean the: Compressor

[Edited on 31-3-2017 by XeonTheMGPony]
View user's profile View All Posts By User

  Go To Top