ChrisDerrick
Chemical
- Apr 8, 2003
- 13
My fellow Engineers, please excuse my ignorance on this subject for I am a not but a lowly chemical engineer. I have several questions relating to the grounding of hoses used to transfer flammable vapors from the headspace of a product tank to a treatment unit.
Currently, we use several types of plactic or coated fabric hoses. A grounding cable is wrapped around the outside the hose and grounded to dissipate any static charge. Is this a usefull method of preventing any explosion due to a static charge created by the movement inside the hose??? If not what is a better method? I inhereted this particular method from my predecessor and am not convinced it is adequate.
My second question relates the hoses designed with a static discharge coil of copper built into the hose. In this type of hose a copper coil is built into the plastic structure of the hose. How does this disipate a static charge? It seems to me the copper coil is insulated from any static charge generated on the inside of the hose.
The treatment system is portable so building a permenant ducting system is not possible.
If it is relevent the VOC's range from o to >100% LEL. Flow rate up to 1000 CFM in a 4-6" hose.
Can anyone tell me how to properly ground my hoses?? Or point me to a proper reference. I have tried several grounding/bonding books but have not been able to find this particular situation.
Finding a proper grounding method is particularly important now because we are currently building a treatment system considerably bigger than our current one. With a bigger unit higher LEL streams will be traveling through the hoses at a much faster rate. I want to have a solid grounding plan in place before new hoses are specked out and ordered.
Thanks in advance for the help!
Chris Derrick
Currently, we use several types of plactic or coated fabric hoses. A grounding cable is wrapped around the outside the hose and grounded to dissipate any static charge. Is this a usefull method of preventing any explosion due to a static charge created by the movement inside the hose??? If not what is a better method? I inhereted this particular method from my predecessor and am not convinced it is adequate.
My second question relates the hoses designed with a static discharge coil of copper built into the hose. In this type of hose a copper coil is built into the plastic structure of the hose. How does this disipate a static charge? It seems to me the copper coil is insulated from any static charge generated on the inside of the hose.
The treatment system is portable so building a permenant ducting system is not possible.
If it is relevent the VOC's range from o to >100% LEL. Flow rate up to 1000 CFM in a 4-6" hose.
Can anyone tell me how to properly ground my hoses?? Or point me to a proper reference. I have tried several grounding/bonding books but have not been able to find this particular situation.
Finding a proper grounding method is particularly important now because we are currently building a treatment system considerably bigger than our current one. With a bigger unit higher LEL streams will be traveling through the hoses at a much faster rate. I want to have a solid grounding plan in place before new hoses are specked out and ordered.
Thanks in advance for the help!
Chris Derrick