Shell and tube avaporators

[skyboy6142]

Dear friends,
Sometimes when I open a shell and tube evaporator, I see pipes such as my sent photo attachment to help oil return to suction of compressor.
But as you know in A/C system as result of high suction pressure oil returns to comp. easily.
Anyway do you agree to install these pipes inside of shell & tube evaporators ? Or they do not do important job ?

Sincerely yours.
15681

[Grizzly]

Pressure and temperature are relevant!
Lower the oil temp and you lower the its Pressure as well.
So lowering both is a good thing is it not?
Thanks Grizzly.

[skyboy6142]

Sorry , I didn't understand :confused::confused::confused:

[Josip]

Hi, skyboy6142 :)


Dear friends,
Sometimes when I open a shell and tube evaporator, I see pipes such as my sent photo attachment to help oil return to suction of compressor.
But as you know in A/C system as result of high suction pressure oil returns to comp. easily.
Anyway do you agree to install these pipes inside of shell & tube evaporators ? Or they do not do important job ?

Sincerely yours.
15681

Sorry,
I do not understand "pipes to help oil return to suction of compressor"
on your attached photo ....

Why?

Those copper pipes are on the water or glycol side and I do not see any connection
of chilled water or glycol with compressor suction ....

... refrigerant is within one circuit (we call it primary circuit) and
water or glycol are in separate circuit (we call it secondary circuit) ....
or maybe I am completely wrong :confused:

To me seems manufacturer is using those copper pipes for some other reason ...
not sure which one ... but hope someone would explain all about ...

Best regards, Josip :)

[mbc]

Hi
This is in refrigeration side
Evaporator is 2 pass design
In running time and foming oil both pipe help to sucking oil for uper part of evaporator.
It is good idea.

[Josip]

Hi, mbc


Hi
This is in refrigeration side
Evaporator is 2 pass design
In running time and foming oil both pipe help to sucking oil for uper part of evaporator.
It is good idea.

thanks for your answer ... if this is refrigerant side (I was completely wrong)
then those pipes make sense ...

anyhow for me (old school) this is unusual design ...

what about cover gasket and sealing ...
to me, seems, bolts for cover are too much apart ...

if you have some additional data or link for this type of evaporators
please, post it here ...


Thanks and best regards, Josip

[Brian_UK]

If that is the refrigerant side then please explain how you would clean and rescale the water side?

[mbc]

Hi
1)The cover of this side hasn't separate upside and downside. And it is one area (same as U )
2) water moveing in shell side and shell has buffer .
It helps water move up and down in shell side to have move efficiency .

[Josip]

Hi, mbc


Hi
1)The cover of this side hasn't separate upside and downside. And it is one area (same as U )
2) water moveing in shell side and shell has buffer .
It helps water move up and down in shell side to have move efficiency .

all clear ....

but to manufacture that kind of separator must be much more
expensive than (refrigerant in shell-water in pipes) due to baffle plates with
holes for pipes (OK cleaning can be done chemically - but need a tremendous
amount of chemicals i.e. full volume as shell ... for me questionable design

Anyhow, product is on the market and people use it ...


... once STAL produced similar kind of oil coolers for screws
(oil in shell with buffle plates-refrigerant (water) in corrugated pipes
quite effective but problematic later on due to sedimentation of oil
on pipes and causing reduced heat transfer .... big pain sometimes

sprayed type of HE is much better solution (at least for me)
http://www.refrigerationcomponents.ca/Products/witt/heat_exchanger.htm


We are here to discuss and think out loud ...

Best regards, Josip

[HwT]

Most of the shell and tube chillers from climaveneta has also the refrigerant side on the tube side. makes for big troubles when leak searching broken tubes.

[mbc]

Hi
When we have wet evaporator we use shell side
normally in dry system (DX) we use tubes side.