Hilliard Emission Controls, Inc.
3100 Edloe Street Suite 350
Houston, TX 77027
888-621-3132
PURGIT emission controls

Nitrogen pading system on a tank barge and an emergency ship inerting job.

PURGIT designed, built and installed the nitrogen inerting system shown below. We can design and install custom equipment to meet your needs. Call PURGIT at 713-621-3132.
 
PURGIT designed this aluminum frame to hold 4 liquid nitrogen tanks. Its modular design allows it to be lifted on and off the vessel easily. Once empty, it can be swapped for a full rack. The four cylinders hold just over 20,000 scf of nitrogen gas. They are attached to an inerting valve that keeps 3" water column (about 1.5 ounces) of pressure on the cargo tanks.

The purpose of keeping an inert gas pad on a tank is to remove oxygen and or moisture from sensitive cargo.

Here the tanks are on a truck going to be refilled. The compact arrangement allows the tanks to be easily transported to a nitrogen facility. This saves the owner by minimizing the cost of refilling. The modular package has the proper diamond placards required by the DOT for transporting hazardous material.

A lifting bridle is permanently installed on the frame making lifting convenient and easy.

More photos of the nitrogen racks. Two racks were ordered and installed on 2 barges.

Another view of the tanks on the barge. The top of the nitrogen tanks. Gauges for monitoring the pad pressure.
Inerting valve on the vessel vapor line. Inerting valve looking forward. Inerting valve view #2.
Inerting valve view #3. Inerting valve view #4. Sense line entry point.


Nitrogen inerting system on a tank ship

The US Coast Guard has a requirement that cargo tanks on some ships must be inerted during discharge. The inert gas system on a particular ship was out of order and it was impossible to get shore based nitrogen to the vessel at the dock. The ship agent called PURGIT. Within hours, PURGIT had a high volume nitrogen generator and compressors ready to go. 

In this picture (looking upstream), the nitrogen generator and compressors are on a barge along side the ship near Norco, LA on the Mississippi River. It is a little hard to see, but there is a hose from the nitrogen generator delivering nitrogen to the ship vapor header.

nitrogen generator
The nitrogen generator needs a source of compressed air. Three diesel powered compressors provided enough air to make 31 cubic meters per minute (1,200cfm) of 95% nitrogen. The system PURGIT designed kept up easily with the ship discharge. compressors for the nitrogen generator
This picture shows the nitrogen generator in the background with air coolers in the foreground. The nitrogen generator needs cool, oil-free air to perform at its best. 

The generator can produce up to 99% nitrogen. In this application, we only needed 93% or better nitrogen.

compressed air cooler
Here is the nitrogen generator with the shift boat in the background. The equipment was loaded at A&A Oilfield Contractors in Jean Lafitte, LA. Jean Lafitte is 15 miles south of New Orleans on Bayou Barataria. Site overview
This 'environmental' fuel tank held the diesel fuel for four days of compressor operation. It has double walls to afford the best possible protection against spills. Oil absorbent pads were on hand in case they were needed. 

There were ZERO spills. In fact, we even collected the condensation water from the air compressors in drums.

fuel tanks for the compressors

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