Engine driven RSW systems
dellori3
2015-03-31 16:21:02
I am here to provide guidance in Refrigerated sea water systems (RSW) for salmon troller’s. My background consists of 50 years as a salmon Troller; much of that was part time. After retiring from refrigeration and air-conditioning, Lori and I fished full time.
I installed my first RSW system some 30 years ago and have done many boats since. You will note I said Salmon Troller; If you are a net boat in Alaska, I am not your guy which also applies to all tuna boats. You will need a much larger system then. My systems consist of an engine driven automotive 4- ton compressor (SANYO SD508 or 10), a custom condenser mounted in line with engine heat exchanger or an option keel cooler. In the fish storage box I have stainless serpentine coils. The target RPM for compressor is 1,000.
Post your questions and I will get back ASAP.
Del
So would this kind of system be for the hold or for pre-chilling before icing? I've often thought a kind of RSW rinse bin would be a cool thing to have.
I don't always do this, but I have on occasion, slushed fish before icing them. It's amazing when you go to unload and none of the ice in their bellies has melted and is still perfect flakes.
dellori3
2015-04-05 15:44:10
Drew,no this system replaces ice all together. It starts with clean sea water and refrigerates it down to 29 degrees by building an Ice bank on the coils.
After bleeding,gut and giiled the fish is dropped into the cold sea water for storage till off loading.
Fish handled this way are very pristine and have a longer shelf life.
dellori3
Trnaround
2015-04-05 16:29:40
Delori3, I can sure see the advantages in Refrigerated Sea Water (RSW), in getting away from ice having always iced or slushed fish. Unless it's changed in Alaska the processors that I have dealt with only want iced or slushed fish because of their concerns with scale loss. In rolling seas even improperly slushed fish (too thin slush mix) can cause this and results in a fish being seconded. Are their ways of taking care of this problem or are there differences in what is acceptable in different areas?
Zedlander
2015-04-05 21:40:07
How much power does an RSW system use? The couple of people I know who use this set up have to have another engine just to run the RSW. Is this still the case? Thanks
dellori3
2015-04-06 16:12:35
On a Salmon Troller the size of the system only needs to be on the order of a/c unit from a large car it uses the very same compressor.
That being the case it will consume around 2 to 4 HP from the main engine @ 1,000 RPM. It will stay up with a 100 fish day (kings). Do you know many high liners that exceed that?
Scale loss is at a minimum especially in deep boxes and all fish face forward.
Dellori3
dellori3
2015-04-06 16:25:14
[attachment=0]Del off loading nice salmon.JPG[/attachment]
dellori3
2015-04-06 22:47:58
RSW condenser—there are three different ways of doing this 1-Keel cooler a through hull to direct contact under the boat. 2-tube in tube water condenser requires a pump. 3- Shell and tube in line with main raw engine cooling water. Of the three I prefer the shell and tube with full water flow required for the main engine. In the state Washington and above, pipe it after the main heat exchanger to add some temperament to the colder sea water. Below Washington and especially California, pipe ahead of the main heat exchanger.
The condensing tempiture is an important factor as it determines the pressure across the TXV and is directly related to the amount (tonnage) of refrigerant the valve will meter.
dellori3
Zedlander
2015-04-09 01:36:40
I am sure this varies with each vessel, but roughly, what is the cost of installing an RSW system? A boat that is set up to slush fish. Thanks for the information too, I appreciate it.
dellori3
2015-04-09 23:31:25
Zedlander, It depends on how much of the work you can do yourself. $2K to 3K would be ball park.
dellori3
Crawfish
2015-04-10 14:51:46
If the tank is setup right this is a non issue as the coils are typically covered by an ice bank so they are smooth. The way my system was built the fish would not get up to the coils typically until two days into a trip and by then they had an ice bank. On a properly built system the fish will be absolutely beautiful when you unload. Plus side to refrigeration is when you fuel up you go fishing. No more waiting in the ice line, no more broken ice machines, if they are biting hard you don't run out of ice. Downside is when your system breaks your sol and it could cost you a trip unless you go buy ice or get it fixed fast enough. When you leave the dock with ice you know what you have. With refrigeration it does not take long to lose your ice bank if your system fails, maybe a day and then it's game over.
I have had refrigeration and it has payed for itself time and time again over the years. I highly recommend a 134A DIY system.
dellori3
2015-04-10 16:05:31
Crawfish in right on with his comments... The design of the fish storage box is a very important part of any RSW system. A deep box and a center divider provide the best product.
dellori3
dellori3
2015-04-10 16:16:24
[attachment=0]Picture 189.jpg[/attachment]deep box
dellori3
dellori3
2015-04-13 17:52:38
Typical engine driven RSW compressor installation. Note the compressor can be driven in either direction.
dellori3
2015-04-13 22:51:22
[attachment=0]RSW Wireing004.jpg[/attachment]Clutch wireing
thediverdude
2015-04-14 03:05:15
I am a small california day troller. Ice is an issue. Only hold 200 pounds and have to pay for 400 lbs. an RSW sounds ideal. How long does it take to chill? Can a electric compressor be installed in parallel to pre-chill the water while at the dock overnight?
Crawfish
2015-04-14 14:43:23
On a properly sized system you can pull water temps down to around 30 degrees in six hours of running. Trolling it may take a full day. It really depends on how many ton system you install, how many fish you put in your tank ...
If you have a small tank you may want to look at a externally mounted chiller of sorts. The coils do take some room in your tank. A small tank will lose a fair amount of holding volume with coils. Placing an external evaporator may make the most sense. Some guys with remote mounted chillers recirculate the water with the large rule wash down pumps.
On a side note some guys in the past have used a 5 gallon bucket as their condenser as a cost savings measure and ran their deck hose into the pail of copper coils. Junk yard ac compressors will work fine or you can buy a new one. Proper lubrication oil and correct amount of oil in your system is paramount.
Pre chill might be a good option for your situation. Designed properly running compressors in series can be done.
dellori3
2015-04-14 16:28:22
The beauty of this system is this: I would leave the slip with the fish hold completely EMPTLY. I DID NOTHING TILL I CAUGHT MY FIRST FISH. Then I would turn on the switch for the compressor and fill enough water to cover the two bottom pipes. We added fish and water in a amount to just cover the fish and when we had a ice bank (2 inches) built up we would shut off the compressor until we had a big pumper on, I would start it again and the boat would slow down just a little till we got him - her in the kill box. That’s the way the days fishing would go. I would take notice of the ice bank at all time and maybe we would need to run it more often if we were catching a lot of fish. Near the end of the day I would decide what to do depending on weather we were off loading or making a trip of more days fishing. As long as I had an ice bank I didn’t worry till some time next day.
dellori3
dellori3
2015-04-14 17:22:46
One of the problems I encountered when I built my original RSW system was the condenser. There was not a desirable one made for boats running off the main engine. As a result of this I designed a full flow one using all the engine cooling water without creating a restriction for the main engine. Protected with no 2 zinc and a cleanable brass cap. The condenser would match up to 250 HP engine cooling systems. On larger engines it may be necessary to parallel the condenser by installing a ball valve in the main line and throttle it down till you have equal flow or the correct amount of water flowing through the condenser.
dellori3
Crawfish
2015-04-15 15:31:44
dellori3,
Is that a transmission style heat exchanger with JIC fittings soldered on it?
dellori3
2015-04-15 15:55:18
Crawfish, no it is a custom built shell and tube Refrigeration Condenser.
dellori3
Ps when in school they called me crawfish because of my last name Crawford???
dellori3
2015-04-15 16:07:48
I should have explained further. If this condenser were to be used for air conditioning it would be rate @ 48,000 BTU's.
It is much larger than a power steering cooler.
dellori3
lone eagle
2015-04-17 17:46:25
my slush has always been a mixture of saltwater and freshwater (ice) ending with a saline solution. Can dressed fish be held in pure saltwater ?
kjwelder
2015-04-17 19:41:36
yes
Crawfish
2015-04-17 20:04:47
We run 40% fresh water, 60% salt water.
Crawfish
2015-04-28 15:35:30
That water pump looks like a TAMD 41 series or maybe AQAD 41 series with an outdrive?
Crawfish
2015-04-28 15:37:09
Where did you come up with the add on pulley extension for the Volvo?
mswkickdrum
2015-04-28 18:16:02
Wait, what if you took a tote of ice with you and then when you got near the tender, you just put a bunch of ice in your RSW chilled hold, then it looks like you slushed the fish. I have heard the SPC won't buy RSW, maybe this might mask the situation and they would just assume they were slushed since they saw them in ice?
dellori3
2015-04-28 18:40:30
Volvo sells that as an add on
dellori3
dellori3
2015-04-28 18:42:09
That water pump looks like a TAMD 41 series or maybe AQAD 41 series with an outdrive?
Correct
dellori3
Scotthmt
2015-04-28 19:22:26
Would this system work on a smaller boat? Space and storage is highly limited and I use a full tote to store my fish, is there a way to adapt a rsw system to a full tote? I love the idea of getting away from ice, it's time consuming, labor intensive, and the cost and availability is also a headache.
Johnnyt707
2015-04-28 22:15:36
Johnnyt707
2015-04-28 22:16:19
there you go scott same company we got ours from different setup but might work for you?
Scotthmt
2015-04-28 23:35:28
Thanks Johnny, I'll look into it for the next season if we can manage to get one, hopefully there are some fish around to even need the chilling.
Johnnyt707
2015-05-01 02:23:47
there will be!!! good luck to you guys have a safe and profitable season
lone eagle
2015-05-06 17:55:10
Anyone know whySPC won't buy RSW salmon?
dellori3
2015-12-01 21:55:26
No, it is a custom built to my specifications Rated @ 48,000 Btu’s @70” sea water
dellori3
An interesting thread. Standard pros and cons. Fact remains ice, when available and packed correctly, consistently yields a better quality product. Before the proponents of refrigeration attack me look closely at the word consistently. I fill the boat up with ice, (I actually slush a tank and have four bonners on deck), and don't worry about it for a week maybe 10 days.
On the other hand, I have acquaintances, friends, running partners, and other assorted contacts that "refrigerate". Without exception, they rebuild, replace, or re-do something at least once a year and usually several times a season at considerable cost. What really cost them is when the system goes down with fish on board in the middle of a bite. Now they've lost fishing (production) time plus fix the problem. That's the consistent part. I've yet to see a consistently reliable refrigeration system, which delivers a consistently quality product, that doesn't cost +$20K. You get what you pay for. I can buy a lot of ice for $20K, or even $3K for that matter.
corsaircrew1
2016-06-18 01:24:05
We have a IMS 7.5 ton RSW system, when testing the system, it builds 98 psi and then the high pressure light kicks on and stops building pressure. I have tried to reset the system via the black reset button on the control panel to no avail. the manual says there is a reset button on the back of the control panel but i am not finding it. any help would be appreciated.
Anonymous
2019-05-11 19:44:15
I am special and well broke part of my engine. I need to remove the bottom half to repair it.. do I really have to take the whole thing out
Anyone got a manual for it in english?
Anonymous
2019-05-14 22:00:14
I am special and well broke part of my engine. I need to remove the bottom half to repair it.. do I really have to take the whole thing out
Anyone got a manual for it in english?
pomfret1uku
2020-05-20 15:45:46
I used to like mine, except the maint. . Usually had to replace compressor every year and fill with refrigerant. Kept the fish at perfect temp tho. The down side is you still need ice if you shut down at night on trips. Good to have some ice every trip to throw first few fish in, too.