Hilliard
Emission Controls,
Inc.
3100 Edloe Street Suite 350
Houston, TX 77027
888-621-3132
|
Hilliard
Emission Controls,
Inc.
3100 Edloe Street Suite 350
Houston, TX 77027
888-621-3132
|
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Have you ever wondered how big tanks are cleaned? | |
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The Clean Air Act requires states to implement plans to reduce VOC air emissions. Osha regulates on site emissions to protect workers. The Texas "state implementation plan" (SIP) requires tank owners to control emissions when tanks are cleaned. That means the discharge vapors must have the VOC removed. | |
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When large tanks are cleaned, the air space may contain volatile organic compounds (VOCs). The concentration of VOC in the air space depends on several factors including the temperature, the length of time since the cargo was discharged and the vapor pressure of the last cargo. The chart above shows a single case for 3 chemicals. Fortunately, in most cases this much VOC is not released. | |
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According to an authority (American Conference of Governmental Industrial Hygienists), air does not disperse evenly in tanks. Air channels. It takes the most direct path from the inlet to the outlet. Little mixing occurs out of the air stream. Pockets of high concentration can remain in large portions of the vapor space creating a problem for the tank cleaner. | |
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The PURGIT method of tank cleaning solves the problem of dilution and channeling. It displaces the VOCs out of the tank space safely, efficiently and thoroughly. An inert gas is released in the tank pushing the VOCs to a control device. A detonation arrester improves the safety of tank cleaning by blocking backflash from the control device. | |
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A comparison of displacement with dilution shows that displacement with an inert gas has a real advantage. It could take ten volumes of air to get the same results as the PURGIT method. PURGIT's technique minimizes the amount of channeling. PURGIT reaches the corners of square tanks much more readily than dilution therefore it is more efficient. Because displacement is so thorough, only one volume may be necessary. Because of this, the cost to combust the vapors is less - the BTU value of the tank vapor actually assists in the combustion. | |
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Under actual working conditions, the PURGIT system can reduce the VOC in a storage tank by 97% with one application. This means a safer, more efficient job. | |
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PURGIT has researched the permitting of temporary control devices, and has been assured by the TNRCC that no permit is necessary. This means that PURGIT can set up at any location in Texas to handle tank cleaning and vapor control. |