good SH = good process ?

[Yuri B.]

Hello
On a cite an ice machine is producing ice flakes whose temperature is 1.5 C . But it should (and is said to prevously do) the ice with - 1C temp.
I have measured the evaporator SH : 11K (- 27 C evaporation ST, - 16 C gas temp.).
I have changed TEV's setting and got the SH 5 K (the same - 27 evaporation, -22 C gas leaving temp). During an hour the machine run but the ice temp did not fall.
What could be wrong with it ? Is not good SH an indication of a proper process ?

(***** R404A. Glass was full. Also, I have been reducing the temperature of the water entering the evaporator, have also tried different condensation tempertures by changing the fan speed - useless)

The one of the explanations I have : the ***** is not quite R404A.

[hvacrmedic]

I'd like to see this 1.5°C ice. Maybe your R718 isn't quite R718?

[Teuria]

Hi

SH = Superheat. It means that all liquid refrigerant has evaporated and gas is "over heated" comparing it to evaporating temp.

So the lower SH = better heat transfer / process, but without liquid separator in suction line SH should be 2-5C and i think that iceflake machines have those.

I don't have that much experience in iceflake machines to tell is that evap.temp ok or not but i think it's cold enough.

And that ice temp, maybe you should measure it with another thermometer. Ice temp , even it is mixed with water should have 0C temp

[Josip]

Hi, Yuri B

Hello
On a cite an ice machine is producing ice flakes whose temperature is 1.5 C . But it should (and is said to prevously do) the ice with - 1C temp.
I have measured the evaporator SH : 11K (- 27 C evaporation ST, - 16 C gas temp.).
I have changed TEV's setting and got the SH 5 K (the same - 27 evaporation, -22 C gas leaving temp). During an hour the machine run but the ice temp did not fall.
What could be wrong with it ? Is not good SH an indication of a proper process ?

(***** R404A. Glass was full. Also, I have been reducing the temperature of the water entering the evaporator, have also tried different condensation tempertures by changing the fan speed - useless)

The one of the explanations I have : the ***** is not quite R404A.

Maybe I miss something, but how we can have ice with temperature of +1.5*C ? Your thermometer is accurate?

Best regards, Josip

[Yuri B.]

The ice coming out is evidently wet, its temp is slightly positive, it is melting, at the bottom of the vat it is falling in there is water, but they want it to be slightly negative temp, not melting so quickly. The ambient room temp is about 12 C.

[PaulZ]

Hi Yuri
Like some other comments I am not sure how you can have +1.5 oC ice. Pure water freezes at 0oC and if there are any dissolved salts in the water the freezing point will be slightly lower, may need to check your thermometer for accuracy.
How did you determine the evap temp and the gas temp?
What type of ice flaker do you have?
I would have expected the ice to be around -12oC at least if you have an evap temp of -27oC.
This would only be correct if you are measuring the superheat correctly.
The ice maker could be oil logged, if this is the case you will have to get rid of the oil out of the evap.
Give us a a bit more info.
Regards
Paul

[krgari]

For r 404 - 27 sounds too low. What are your pressures?
For Hoshizaki flaker your pressures should be about 30 - 40 lbs suction

[SURESH YADAV]

Dear...
Superheat in the system use for safety of compressor to ensure that there should be no liquid refrigerant go to the compressor. If you are using high superheat don't shows that you ice temp increase.

[Magoo]

Flaker should be delivering -18'C flake ice, clean and dropping off in sheets, have you checked the salt content . The flaker drum is starved for liquid or possibly saturated with oil. Wet and mushy flake is not good

[Yuri B.]

Thank you for your answers !

As my "boss" does not allow me to buy instruments I need for the job, I decided to let him solve this problem himself !

[Teuria]

Thank you for your answers !

As my "boss" does not allow me to buy instruments I need for the job, I decided to let him solve this problem himself !

Hi

If "The Boss" can fix it or maybe you, let us know what caused that problem.

[Josip]

Hi, Yuri B.

Thank you for your answers !

As my "boss" does not allow me to buy instruments I need for the job, I decided to let him solve this problem himself !

Not sure, but in your original post ... as my "f....r" describe the attitude of your boss much better ... anyhow, let him to solve that problem ...

Best regards, Josip