Running Engine Blowers

I've always thought of diesels as big air pumps and that an intake blower was not needed for regular operation, but only to cool down the ER after shutdown. Add to that my fear of salt in the works, and I'd take an awful persuasive argument for me to believe that running them while operating was wise.

I only run them for cool down and only then, when I have to do maintenance for the next day.

Some of the newer boats have air/salt traps. One company I remember was called T systems that some mfgs used or could install after factory.
Some others have coarse plastic or alloy mesh. All of these systems required an over board drain and required rinsing (to get the salt off).
Then the plain air box with a drain. Still needs rinsing.
Most blowers usually draw air from the ER and blows it out. Making the air traps/filters do it's work.

I prefer not to run them during operation; not only more hours on the equipment, but a fan for bad things (fire) that some boats to this day still do not have blower shut-downs.

As commented above, Diesels draw lots (LOTS) of air naturally, let them draw what they need. When not running and your still on the ship, turn the blowers on to help the comfort in the living spaces.

Good blowers are nice when you have to pull maintenance or access the ER.

I've been on boats that all they are was noise makers and never moved the heat (or any air) out at all.

Hi Ralph,
Your thinking about the company called "Delta T" out of Riviera Bch, Fl. Very good engineering for de misters and intake traps & fans. Their equipment is now finding its way aboard ships after merging or having distribution rights to a line of German axial fans.
Very informative website at deltatsystems.com

That's them. Not heard that company name in a while. Well,,, I'm not in those old shoes anymore either.
Glad they are still up and doing well.
Thx

Delta T is standard equipment on new Vikings. When I was working for Viking one side pulled air in and the other pushed it out. I thought they needed to be reverse-able so that if you had a beam sea on one side you could push air out that side while running.

Blowers usually pull air out of the ER, they don't bring it in so they shouldn't bring salt in.

The 70 footer I run has large AC blowers which I only run after shutting down the engines to extract the hot air out and reduce temp in the ER. In our case there are quite a bit of electronic stuff in the ER like battery charger, water maker, etc... So every degree counts.

As someone else mentioned, if you don't have blower shut down tied to the fire system running them underway isn't a good idea as in case of a fire they will suck the agent out.

Surely it makes no difference to the salt getting in the ER if you have a fan that blows into the space or one that sucks out and the air is drawn by this.

On the boats I am most familiar with we run 2 supply and 2 exhaust fans, these have an automatic mode when they are controlled by a pressure switch so there is always a slight positive pressure.

One of them is also reversible and fed by the EDG to be used if CO2 has been released in the E.R. to help ventilate it prior to re entry.

Both my ER blowers fill the ER, not pull from.

I seriously doubt the architects of these boats would put in these huge fans if they were not meant to be run while underway. We have two huge delta t fans connected to freq. drives. Is there not some engine benefit to having them run while under way?

Anything in the owners manual? Response from a factory reps phone call and hard copy of the company's theory of operation?
Without any higher authority,,, Leave them off while running. On when you dock after a run or have to go in the engine room.

Is there not some engine benefit to having them run while under way?
There is so much air sucked in by the engines while running. I cant see anything but a load on its power supply and time on the blower motor for not much (if any) benefit. .

"
Approximate consumption of combustion air for a diesel engine is 0.1 m3 of air/min/brake kW (2.5 ft3 of air/min/bhp) produced.

Cat specifies both requirements for air cooling and air combustion. If a pair of c32 is trying to achieve 3200 hp by burning 200gph, it will need a certain amount of air to achieve that design goal or the fuel won't be effectively turned into Hp as designed. Perhaps if you are going slow the need for increased air flow is not needed. But this is why builders are spec'ng $20,000 engine room fans. Not just for cooling

https://marine.cat.com/cda/files/4387976/7/LEBW4971-05 (1).pdf

Enjoy.

How do you keep the engine room temperature down when underway if the only air being introduced to the engine room is that for combustion?

It's for both combustion and cooling.