Chemical Tanker

Hello Everyone
I am a final year naval architecture student and have taken Chemical Tanker as final year project. I am planning to ply between India and Malaysia with Benzene and Bitumen Cargo from India to Malaysia and back respectively. I wanted your opinion about the feasibility of taking these two chemicals as cargo and want some opinions if it is economic to clean the tanks every time the vessel reaches its destination. Also I want some suggestions with other chemicals.

 

Is the bitumen solid? Are you planning on heating and pumping it out or is it in blocks?

 

Some chemical tankers need cargo heating to approximately 60 ° C, for the loading / unloading. This is a completely normal case, which gives rise, however, to large structural problems, whose solution is already known. There is nothing new or impossible. It is difficult and, for a first draft of a student, too complicated, in my opinion.
The cleaning of tanks, all chemical tanker must be very careful, it simplifies making the whole structure reinforced tanks go on the outside of the tanks.

 

Thank you sir.
Yes the tanks need to be heated above 60°C and it will cause a major structural problem and as you told that the reinforcement will be required on the outer side of the tanks' go. Also it will affect the tank lining. Can you tell me what kind of lining and reinforcement will be necessary for such a condition?

 

I need to heat it since am carrying it in a Tanker. So it´s in liquid form with a suitable viscosity so as to allow easy flow rate through pipes.

 

You have an example of such a structure in my gallery. See picture "Cargo Hold".
If you need more information, please, use my e.mail : 657677483@orange.es
Regards
Ignacio López

 

Thanks to everyone. But a bad news.... My guide didn't approve my project for carrying bitumen. So am taking Sulfuric Acid from Japan to Chile and Copper Sulfate solution in the back journey. However Copper Sulfate is generally carried in crystal or powdered form but I think carrying its solution will also be feasible and quite profitable. Do you think that there will be some problem in carrying these chemicals? And is washing necessary every time I load a different cargo? And which tank lining will be recommended for such a tanker? :?:

 

I do not know anything about chemistry or chemicals. What I do know is that some chemical tankers carry stainless steel tanks. In other case, gives the steel a paint scheme that produces a surface comparable to ceramics, this totally stable and unassailable by the acid. And yes, when load changes now require cleaning tanks. This is done in a few special places that exist in some ports, not all, in order to download the cleanings.

 

If all you are carrying is these two chemicals, you just need to find a surface that is immune to them. Off hand I would think a spray on coating would be the easiest to manufacture since you could build the tank out of anything, then coat it. If a coating can't be found, then you need to start looking for metals that are immune on their own.

Honestly I don't see this as a naval architect problem so much as a material science one. Go enlist a grad student in a metallurgy department for some suggestions. Some quick research indicates tantalum is one of the better metals for sulfiric acid corrosion protection, but I couldn't find anything on how it reacts to copper sulfate.

One of the big issues when carrying highly toxic chemicals like these is how to protect the crew in the event of a spill. Automatic wash down stations, high volume ventilation, emergency equipment, ect all need to be taken into account.

 

Stumble I agree that, at firts glance, it is not a problem for naval architecs but I am a naval architect and worked in shipyards that built chemical tankers. I contributed, worked in their construction. One of the vessels carrying stainless steel tanks. In several others, we chose a painting that, when dry, adopted similar properties to a ceramic material, impervious to acids.
Both processes have their advantages and disadvantages.
What I've had to do, being a naval architect, is designing and establish the appropriate structure for each case, and define construction details that each option requires.
Of all this adventure for over 15 years so it is possible that, as Stumble says, somebody has invented a spray that makes things easier. I do not know.

 

Tansl,

Of course a NA may have to deal with this in real life. But when doing so you have a team around you, and the resources to get metallurgists involved, call chemists to identify safety precautions for the specific chemicals, wash down processes, ect. All of which could change the design.

Just as an example, lets say when these two chemicals interact there is no reaction at all. Then you don't need any real strange tank wash down issues. On the ther hand lets say when they interact they explode violently, and put out a gass that eats steel away in minutes. Well then we need to take a lot more precautions to ensure they never touch. My point was just that I don't think an undergraduate student has the resources available in terms of experts to address this reasonably.

Just as an example, I know a few salesmen in the coatings industry. If I knew of a NA who was actually building a ship like this, I could send the NA to them, and they would be happy to spend the time to identify exacally the right coating (if they have one) for that specific application. It would be much harder to convince them to do so for a school project however.

 

Greg,

I know some great salesmen. And I know some bad engineers.

But, for some reason, I feel uncomfortable expecting more out of sales engineers than out of a future engineer.

Or, is NA not a real engineering discipline?

Does that make sense?

Wayne

 

I think you have too highly of what a naval architect is. NA always needs a lot of consulting experts in many fields. They must deal with a lot of different problems and his mind is not an encyclopedia. A few years ago, some students, were trying to learn a lot of everything. Fortunately, specialization was invented. The na, and other wise, then stop trying to know everything.
Any tanker must have a system of tank washing, either chemical tanker or not.
Not only must avoid gas fumes or explosions, we must also prevent contamination of last product residue above the current load. And for that, wash tanks very very well.
The transport of chemicals, not only boats, have a problem that you need to know before you comment.
Wayne: In my country a na is more like an engineer than an architect, but has a bit of everything. But overall, a na is not supose to make beautiful patterns.
In yards there has always been doubt whether the purchasing departments and marketing, was convenient to place engineers-commercial or a commercial-engineers. In the end, as always, was chosen for the position the best person to the job, regardless of its title (degree). Do not fall into the mistake of thinking that the title makes the man.
Regards

 

Wayne,

I have a huge amount of respect for NA's. but they have a specialized job to do, just like the rest of the guys working on a boat design. In my experience they are the ones that have to bring it all together into a cohesive package, but everyone's input is important. Just as an example, one of the marine jobs I am working on had a meeting Tuesday at that meeting there were 15 different people all there to provide expertise in specific areas. Then add in all the competing interests, and it can turn into a quagmire.

No NA could possibly have all the information they would need to design this boat by themselves. Heck we had 5 different types of engineers, plus three different types of material experts, and since this boat is carried in a cargo plane two different aircraft experts. This is probably an extreme example, but it happens.

My only point is that a student project doesn't have the resources to bring this disparity of expertiese together to solve a problem. If this project was about moving grain, or boxes, that's one issue. But here we have real problems carrying and handeling specialized chemicals that are incredibly destructive to both metals and human health. The specialized precautions that need to be designed into this boat go far beyond what I would think is reasonable to expect a NA to deal with, or have any knowledge of.

 

Stumble, I basically agree with what you say about the na.
In relation to the project chosen by our student, I also agree that it is too difficult for him but probably he will not need to do what we mean by a project but rather a blueprint, without going too deeply into details . It is also true that, regardless of the material of the tanks, or the lining of the walls, these ships pose problems of naval architecture interesting.