– Urgent – Blast Chiller Problems – Urgent –

[olivero]

Yeah, I guess that’s true.

 

Based on the pressure specs I scraped from Delfield, I think its 10 – 20 TD, Box can pull to 0 Max so the refrigerant is at about -20*F  to -11*F at those pressures.

 

Then as the box temp drops and suction pressure drops, you end with almost a -40* TD with it at 4 PSI.

 

Pretty hefty. I think it could be made more efficient though, for some reason, I am not completely satisfied and willing to let it be fixed.

 

Unit has, soft chill, blast chill and blast freeze. Each one operates their own way, how can you design a system to run efficiently in 3 different ways? Beyond me.

[john]

badbozo2315

I did know that since (as admin) I can see your e-mail–and I dig for information.

Interestingly, I didn’t know you guys were mandated to only post in certain forums. I was hoping the company would say “yeah, use your expertise across the site.” 

I suppose they’re at odds with giving too much information away. Don’t want to take jobs from the techs (and I truly do not, of course), but we can’t have a working database without users who possess the technical knowledge.

[fixbear]

You can’t.  for each working temp change they have to give up something. Delfield is calling the compressor a 6 hp,  but Copeland say’s 7.5. That means that Delfield has found a way to derate it for the wide range.  Is that what you balancing valves are for?  Does this unit have a crankcase regulator valve or suction pressure valve?  They only show a refrigeration schematic for the T15.  Being water cooled they don’t need a head pressure control. Being in Florida it would never need one anyway.  That would also explain the undersized metering.

[olivero]

Right, I don’t see how it can ever really run as efficient as possible with the 3 settings all having different TD’s and pull down temps.

 

Balancing valves are to control head pressure, they control the supply and return of water, not refrigerant.

 

 

No other valves than the service valve on the suction and liquid side of the compressor, like right off the compressor, not inline.

 

Not sure what a Crankcase regulator valve is, still kind of new to this cold side of the field.

[fixbear]

Makes it so the suction can not go above a set point so that you can have a low temp compressor run a high temp application without overload. They are sweet, to dial in full load without tripping breakers or fuses.  Makes it a method to convert a walk in freezer to a plain walk in.  Also has a tap you can use for a suction pressure control. 

[olivero]

Wow, that sounds awesome.

 

Wonders of the trades, somebody figured it out .

[fixbear]

Balancing valves are to control head pressure, they control the supply and return of water, not refrigerant.

That troubles me.  Do the still have a head pressure water valve to keep it constant?  Without this the ambient and load will make it drift all over the place.  With the water regulating valve the head will stay within 5 lb’s.  They could of  added the bypass for when and if the valve fails.

 

Supply to the heat ex-changer should be unrestricted and above 30 psi.  It should then go to open drain.  Unless it is being cooled by brown water instead of potable. 

[olivero]

Yes, there is head pressure water valve as well.

 

It is brown water circulated, well, with chemical treatment of the loop its more pink than brown.

[fixbear]

That explains it. The Valves are to cjhemical clean the system.  Cooling tower or ground sump?

[olivero]

Neither, direct expansion system with the condenser coil outside with 3 horizontally mounted fans.

 

The valves only adjust the amount of flow in the pipe, the water is treated to prevent chemical corrosion and whatnot.