Hi all,
I have seen some dole plates kicking around the SE fleet and mainly have experience with blast freeze systems. I'm looking at buying a vessel from OH! Canada that has a dole plate system. What's the deal with the dole? Similar core temps for the fish as blast? Maintenance issues vs. blast? DEC weirdness? Thanks.
Tim
squarehead
2008-12-07 03:24:34
I currently use a plate system. It works well and requires little maintanace; however due to the fact that the fish freeze from the bottom up (as they lie on the plates) you really have to focus an the "golden" hour, if the fish don't get into the freezer quickly the quality suffers and shows up in the form of closed bellies.
this may not be much of a problem but, as a mom and pop operation, it can slow production if you get into a bite. you may have to process fish EVERY time you pull a line . meaning your buddies might put down 300 and you only 200 on a day when the ice boats are getting 400 . having more help on board would help. a combo plate /blast is what I wish I had, because the wind freezes from all sides at once, also a rsw system to chill and keep fish on deck. many tuna boats have this set up (rsw on deck) and I believe it would improve my quality. hope this helps!
Chalkie
2011-10-27 15:35:37
I saw an article in National Fisherman about a Bristol Bay gillnetter (32') with RSW. Has anybody installed this for a similar sized troller instead of depending on tenders for ice to slush with?
Salty
2011-10-27 16:45:38
I think there are a couple of guys with RSW on trollers. I am thinking of installing a system to supplement the cold water and ice available at the tenders and plants.
kjwelder
2011-10-28 19:44:02
I have a 43' canadian boat that currently has a plate freezer system. There are at least a couple of things that I would consider if I were looking to purchase a freezer boat.
Make sure that your product will meet your market's quality standards. I think most buyers want a minimum of at least a -10 f core temp. The higher end markets want even colder fish, like -24 or -30 F.
There are different types of "dole Plates." Dole is a brand. The older plates were thin galvinized sheets of steel with copper tubing inside. Expect to replace these. Newer plates are extruded aluminum with elbow welded on the sides to create the evaporator circuit. The main problem with plates is that they tend leak refrigerant at the inlet and outlet of the circuit.
Another issue is that plates freeze by conduction or contact. In my expirience it takes about an hour to freeze a pound of salmon. No problem with a six pound coho. I have enough plates for about 150 cohos every six hours. But with kings a 20 pounder takes all day or more because the more they freeze the more they insulate themselves and it takes longer to freeze to the core.
Yet another issue with plates is that once you remove your product and stack it in the bin it will warm up to the ambient temperature of the hold. Now isulation is imprtant.
Blast systems will circulate the air over the evaporator and over the product. I know of lots of fishermen that replaced plates with a blast system and no one that replaced a blast with plates.
Before you buy the boat, use your purchase and sales agreement to get a "sea trial" where you run the equiptment. Freeze some stuff and see how cold it gets. Look at the compressor and metering device to see if the system capacity is in the ball park of how many pounds you want to freeze in a day. The system should be oversized by about twice, because it will never operate at the capacity that it was designed for. Meaning a 5000lb system will probably only suck down 2500lbs.
Good luck there's nothing easy about freezing,
kj