Recently, we have actually been reading as well as listening to reports from mobile offshore drilling rig proprietors that a number of Methods are mosting likely to be piled– regrettably, this is a cycle that we have been via before. From past experience, we have found out that laying up rigs with proper dehumidification equipment installed helps to protect the honesty of the listed below deck devices and the quarters. When it comes time for the gear to be reactivated, it counts on the right faster and in better problem than a rig that is cold stacked at dockside or in the middle of a bay.
Iron starts to dramatically wear away (rust) at 60% RH as well as over (Garverick, Deterioration in the Petrochemical Market). According to the American Bureau of Shipping, for the best lead to preserving listed below deck devices and also machinery areas, they advise “complete dehumidification at 35% to 45% RH … to prevent sweating or moisture deterioration damages”. Holding a family member moisture of 40% to 75% will protect the integrity of seals and also gaskets. Provided all these factors, we typically advise around 45% RH for gear layups.
There are 2 fundamental sorts of Dehumidifiers (DH) readily available:
Desiccant Wheel DH Units
Refrigerant DH Units
Desiccant Wheel DH Units are used by the US Naval Reserve Fleet and are the “gold requirement” for Vessel Lay Up Malaysia due to the fact that they are not detrimentally impacted by reduced ambient air temperatures like Cooling agent DH Units.
HOW IT WORKS
The Desiccant Wheel DH Device utilizes a revolving, regenerative, open fluted matrix wheel that is fertilized with a hygroscopic, safe component. A humidistat monitors the family member humidity in the area and also transforms the DH Device on or off to achieve as well as maintain the preferred humidity set point. The humidistat can be built into some DH Units at the return air inlet, which is where the air is mosting likely to be one of the most humid.
Dry air is larger than humid air, so the dry air will certainly displace the damp air as well as push the humid air back to the DH Device, which is mounted in the dehumidified space. Dry air will also seek areas where there is even more humid air. So hard-to-reach locations, crawl spaces, tanks, as well as spaces that are allowed to be common to the location being evaporated will additionally be dried out as well as properly preserved.
Generally, we recommend one dehumidifier for all the listed below deck machinery areas as well as one dehumidifier for the quarters– the exact same method relates to both rooms. Evaporating the machinery areas below deck is apparent. Nonetheless, it is likewise a good idea to dehumidify the living quarters if the rig is not mosting likely to be occupied throughout Vessel Lay Up Malaysia. Dehumidifying the quarters prevents mold and mildew as well as mildew from growing in the encased quarters– all the bedding remains nice and completely dry and also the above ducting and framework does not corrosion.
There are additionally a variety of semi-submersibles with DH Units in the caissons and pontoons, which ought to be made use of for preservation of these areas in the event of a Vessel Lay Up Malaysia.
To establish the proper size of the dehumidifier, we would certainly compute the gross volume of the location to be dried out and afterwards figure that the DH Device will certainly transform that gross quantity over every 4 to 6 hours on a piled rig. This generally ends up being a small DH Unit such as a 600 CFM or 1200 CFM dimension system.
With a Desiccant Wheel DH Unit, we extend flex air duct that handles the dry supply air to the farthest point away from the DH area. Then, the return air circulates back to the DH Unit via all the open doors. The resurgence air intake and exhaust needs to be ducted from outside the dehumidified room to prevent ambient, damp air leaks. Affordable, protected adaptable duct can be utilized.
You can additionally make use of really small DH Units (60 CFM) to dehumidify isolated areas such as crane cabs as well as drillers/dog homes. Generally small Cooling agent DH Units are used in these locations and just a drainpipe line needs to be run outside of the location.
Generally, rig hands and also rig electricians are greater than efficient in installing a dehumidification system on a rig layup, which eliminates the pricey demand to hire an outside service provider for this work
BE PREPARED TO PROGRESS
Nobody likes to consider gear lay-ups. That is not what this energy industry is everything about. We want full steam forward. Not turn around. Not quit. However a gear that is effectively maintained and dehumidified will certainly endure being briefly out of action and will be able to return to procedure quicker than one that is not.
Should the need arise to stack a rig, get in touch with Eldridge and we will certainly assist you with dehumidifier application, sizing, as well as flex duct/fitting directing design as a value included service.
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