PDA

View Full Version : Cattabriga Ice Cream Machine



Abe
23-02-2002, 10:02 PM
Have a prob with a Cattabriga Ice Cream Extruder. The machine is water cooled with a 7 or 8 HP semi hermetique condensing unit with a shell and tube type condenser.

On the control panel there is an Eliwell controller with shows a reading. When the reading displays 5.6 or 5.8 it means the ice cream mix in the evaporator barrell is ready for extrusion and you pull the handle and out comes this firm semi- solid hard ice cream .

The problem with the machine is this, it starts off okay, but then the reading drops to 4.6 and at this stage instead of firm ice cream coming uoy, liquid mix pours out. ( Obviously very retarded refrigeration effect)

The operator has to stop dispensing and wait for the reading to go up again to 5.6 or 5.8 before he can strart extruding again.

In normal mode the machine should maintain a reading of around 5.6 and the consistency of the ice cream should be maintained.

I had a look at the machine. HP is around 150 psi, system runs on R502 , suction pressure is around 30 psi.

A previous engineer very recently changed the TEV, he changed only half of it, the part with the bellows and capillary. Its a Danfoss TEY5 R 502 valve with a serial number 067B3257

I know with these machines the valve has to be spot on.

I changed the filter, removed all the gas and refilled with Isceon R69. The machine is maintaining a reading of around 5.6 but the whole compressor body is iced over. ( Liquid refrigerant returning back to the compressor) I have fine tuned the valve, but suspect the valve fitted is wrong

Distributor will not give me information on the right valve to fit. Last engineer took away the old valve . I think this valve is too big and allowing excessive gas to go through, too large an orifice. By meddling around with superheat settings I am probably helping a little, but liquid still getting through.

Bulb is located behind somewhere and I am presuming that engineer has secured to suction pipe firmly.

Machine is a Cattabriga 1927
Freezemat 500/1CPS

Machine Type FR2 500/ICPS
Assembly Year ILAT

R502
16.9 A
35.8HP
Registration No 217 500001

herefishy
23-02-2002, 10:40 PM
When it comes to ice machines (and ice cream machines), I won't even consider tampering with or employing after-market TEV's (or compressors for that matter). You may get a component with the same "numbers" off of the shelf.... but that doesn't mean it is the same creature as the OEM.

If the TEV has been tampered with, in the manner that you described, I would "go with your gut", and get the OEM part from the manufacturer, and start there..... might also consult with mfgr on drop-in refrigerant recommendations......

herefishy
23-02-2002, 11:28 PM
Iscecon 403B..... refrigerant mfgr suggests that higher superheat setting may be required for conversion......

@30psig, S.S.T. = approx -20degF.

Andy
24-02-2002, 12:07 AM
Hi,whats your suction superheat, whats your discharge temperature. 69L has an increased capacity over 502. Also your evaporating pressure may remain similar but your the temperature will be lower. Main thing your head pressure is way too low, it should be over 220psig. Put a thermometer on your suction near the eveporator outlet and check this against you saturated pressure, you are looking for a superheat of of 6c aproximately, and certainly bellow 12c to start with. If the other Engineer just changed the power element the valve is original type. My guess would be suction superheat allowing open up the valve. Also the power element will have the tag showing the oriface number attached, duty can be found from this. An iced suction alone is not a concern, provided that the superheat at the evaporator outlet is ok. As for the discharge temp a discharge that you can comfortly hold with you hand indicates either no flow or liquid entering the compressor. Also is the cop pumping ok, take it's run current and check this against the rating on the compressor. Have fun.
Regards. Andy.

al
25-02-2002, 09:13 PM
Have you checked the barrel as the scrapers employed can be worn but not visible to the eye! I'd suggest a kit from the distributors and replacement of o rings etc, as most refrigeration problems on these machines may be related to poor maintenance and cleaning of internal parts by the shops.

Abe
26-02-2002, 09:04 PM
Al,

You hit the nail on the head. Problem was with the barrel scraper
Was fitted by the operator the "wrong" way. Refitted it and refrigeration system is working perfectly now. Holding 5.6 on the dial consistently.

Incidently distributor sent me a fax today confirming that the TEV is the correct one. So they have helped.

As you suggest, changing the O rings will be prudent, so Ill see if I can get that sorted.

Thanks to everyone who have helped.

Cheers

al
27-02-2002, 08:25 PM
Thanks for the feedback Aiyub, wish my customers could be so positive!!

Abe
05-03-2002, 09:09 PM
Hey Marc,

I never thought Id see the day I taught you something!!!
Geez...........I got a lekker feeling and feeling kinda smug

Tot Seins

Gary
06-03-2002, 12:01 AM
As Mark Twain once said, "We are all ignorant...about different things".

pezagent
26-04-2003, 01:06 PM
FYI, most problems with ice cream batch freezers that aren't freezing the mix properly are because of the dasher--sometimes the dasher is bent or hasn't been put in properly. As the dasher scrapes the mix off the sides it removes heat from the mix and bingo there's your ice cream, if the dasher is bent out of shape then the mix won't freeze properly at all.

Might be a good point to check before wondering if the cooling system is wonky.

:)