Super Blast Air Gun Used to Clean Cargo Holds on Ships

Imagine those large cargo ships that transport products like coal, grain, fertilizer and other like, dry, bulk materials. Now imagine yourself as the person responsible for cleaning out the cavernous holds once they have been emptied.

A recent customer from Quebec called me to see if we had anything better than what they were currently using to clean out the hold. They were using  a 3/4 steel pipe of 2 meters length connected to a 1-1/4″, red, rubber hose. Their current method was working for them to a point, but they still were not able to project force to a reasonable distance to blow off the features near the top of the cargo hold. So, they had to use various lifts to get themselves into proper position and to get close enough to generate reasonable force on the areas to be cleaned.

Once I had a clear picture of what the customer was doing, the thought occurred to me that the reason why they were unable to produce a significant force at distance with their existing set-up was that the pressure drop through the supply hose and 2 meter pipe was so extreme that the customer could not maintain reasonable pressure at the tip of the pipe where he needed it most. This was because he was working with an unrestricted orifice (the end of the pipe).

I use the analogy of his situation being like that most of us have experienced when we wash a car with a garden hose. When you turn the water on, you have a nice, free-flowing stream that comes out of the hose end and shoots out from the hose maybe 1 meter or so. While this is OK for watering the garden, it isn’t so good for removing that stubborn mud from your tires or from under the car. So, what do we do? We screw a nozzle onto the end of the garden hose. Take, for example, the classic, brass hose nozzle that adjusts from a wide spray to a focused jet. When set to the focused jet, the water now has a lot more power and can do more work. The stream has the capability to now shoot out 6 – 8 meters or more from the nozzle. A huge improvement over the hose without the nozzle.

You can probably guess where I’m headed with this. Yes, I recommended our Model 1112  3/4 NPT, High Force Super Air Nozzle to the customer. It was so convenient to install the nozzle as the 2 meter pipe already had a thread on it (which had to be cleaned up a bit from being knocked around). So, he ran a die over the thread, installed the nozzle and began using the new set-up.

The result was quite interesting, where he previously only had effective blowing force up to about 2 meters, he could all of a sudden produce good, cleaning force at 8 meters plus. This extension of his effective cleaning range allowed him to increase his productivity and reduce cleaning time.

What was the key to success? Very simple, the nozzle backed up the compressed air flow so that effective pressure could be developed right behind the nozzle. With the pressure available right behind the nozzle, it was able to produce a much higher blowing force on the walls of the cargo hold. Customer was happy. End of story.

Neal Raker
Application Engineer
nealraker@exair.com

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