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AlexLPD
17-03-2014, 11:58 PM
Hi, well this seem kind of a redundant question butm I just want to be sure:

The chiller, ia about 3.5m Long by 2.3 Width by 2.3 Tall, I changue the condensign unit to an
Maneurop 3HP adjusted to -6°Evap and 45°C on the condenser, the evaporator, an Bohn maneurop I think DT208, was installed.
The meat is always on the rank of 1°C -4°C, and well the refrigerattion systems seems to be quite fine actually, however here comes the triky part;

The previus instalation, wasnt made by me, so the old "installers" decided to put just a thermal breker to on/off the evaporator, as result the evaporator always is on, and there is plenty of air in the chiller.

And the owner has this complain, about some darkening on the meat (the direct exposed area to evaporator air flow) and some red-like bool darkening, a bad look for the meat.

So, I installed some electric control panels on the past, and for the meat cameras we always stop the evaporator fans, until the thermostat reach again the temperature of operation.

Never the least I want to know how is made in other places.

I was thinking for this particular application to use some microcontroler.
Mian Idea beside of the normal operation is to segment the 5fans on the evaporator and when the compressor is off, let just one of them on, the next time the systems starts, will operate normally, then another fan will start and so on...

Main idea will be for keeping an air circulation in the room.

Or just use the all electric- analogue old school control, to start the evaporator just untill we reach the desired temperature, and then stop the fans, untill the refrigerattion cycles start again.

Any tougths?
-Alex.

cadwaladr
18-03-2014, 02:28 AM
I would keep the fans running,is the superheat set correctly and maybe you need to regulate the cooling capacity maybe by fitting a regulator to the suction side of the compressor.

nike123
18-03-2014, 08:42 AM
Here we use, for meat chilling, pasive evaporators (natural air circulation - no fans).

AlexLPD
18-03-2014, 05:38 PM
Hi Brianiac, yes like the cold display cases, I think it may be the excesive air circulation on the surface of the meat.... any way... I will give it a try, and Let you guys know how it goes from here.

Thank You!

nike123
18-03-2014, 06:23 PM
Also, if you are using forced cooling, than TD of evaporator should be as low as possible to keep moisture at high level!
Usual TD of evaporator for meat chilling is 6-7K to achieve suitable air moisture level of about 85%.

Generally, TD of evaporator (https://nationalvetcontent.edu.au/alfresco/d/d/workspace/SpacesStore/314bb28e-2029-44c1-9911-a815b25539f1/13_06/content_sections/04_vapour_compression_systems/docs/vc18_evaporator_td.doc) sold in your local store is calculated (selected from catalog) and dimensioned as 10K. Therefore, you need almost double size of evaporator with same amount of air circulation to achieve that low TD and suitable RH% in that cold-room.

AlexLPD
02-04-2014, 07:25 AM
Also, if you are using forced cooling, than TD of evaporator should be as low as possible to keep moisture at high level!
Usual TD of evaporator for meat chilling is 6-7K to achieve suitable air moisture level of about 85%.

Generally, TD of evaporator (https://nationalvetcontent.edu.au/alfresco/d/d/workspace/SpacesStore/314bb28e-2029-44c1-9911-a815b25539f1/13_06/content_sections/04_vapour_compression_systems/docs/vc18_evaporator_td.doc) sold in your local store is calculated (selected from catalog) and dimensioned as 10K. Therefore, you need almost double size of evaporator with same amount of air circulation to achieve that low TD and suitable RH% in that cold-room.




Well this is some reius piece of information, many thanks to you to upload this, I will re-chek my capacity calculus, to see how this comes in.

Thank You Very Much again.

-Alejandro Santiago.