Open system chiller 1

[cmijares]

What is the recommended maximum water hardness for an open chilled water system.

The system is for an industrial process and it uses well´s water and in this region its very hard (about 400ppm)so I have to know how low do I need to get the water hardness to select the proper water softener.

Thanks

 

[quark]

Ideally it should be comercial zero i.e less than 5 ppm. Atleast, make it below 30 ppm.

Regards,

 

[remp]

If I were you I would use a plate heat exchanger...closed loop CHW on the chiller side and open loop well water on the secondary side. A plate HX is much easier to miantain than a chiller evaporator.

 

[imok2]

In my opionion, if you keep it below 120 PPM you shouldn't have any scale problems. you can go to this web site for more info:

http://www.corrosion-doctors.org/NaturalWaters/Langelier.htm

 

[cmijares]

Thank you all for your responses, they have been very useful.

I have another issue with this application. the chiller is going to be in a very dusty place, actually the chilled water is for a concrete mixer and there's cement everywhere. Any comments?

 

[abcmex]

cmijares,
Can the concrete get into the Chilled water system?
What do you mean by an open chilled water system?

open refers to
a) one time cooling OR
b) recirculation without a pressurized expansion vessel?

the water quality depends on the case.

 

[imok2]

Yes I have a comment...If the cement gets in the chilled water then instead of a chiller... you will have a cement mixer!!!

 

[cmijares]

no, the cement won't get in the chiller evaporator, but the chilled water into the mixture..., my concern is about dust in the outside of the condenser (which is air cooled) and the loss of eficiency.

By open system I mean one time cooling.

 

[imok2]

cmijares Run an air line to the condenser, install some air nozzles near the condenser, install a time clock and a selenoid valve in the air line and time it to blow air ai an interval required to keep the cond clean.

 

[abcmex]

As always the problems are more in the comunication, let me get a clear picture:
a) you chill water for a concrete mixture
b) your chiller is air cooled (no CTW).

Problem 1. Hardness on the water to be used as chilled water. Check the langelier index to see if you will have precipitation (mainly when you heat the water). Calcium per se will not make deposits.

Problem 2. Air cooled condenser. Consult with your supplier to see if you can install a filter (mat) before the ventilator or Finned tubes.
RGS