publisherALPTEC
time2020/10/14
The oxygen and acetylene pipes in factories
and workshops must be connected as a whole and grounded. All other pipes and
equipment that may generate static electricity, such as oil conveying
equipment, air compressors, ventilation devices and air pipes, especially air
pipes for local exhaust, must be connected as a whole and grounded.
The relevant equipment and pipelines of
each system in the workshop should be connected reliably, and the contact
resistance at the joints should not exceed 0.03Ω; when the two bolts are
normally tightened or metal jumpers are used, there should be at least two
grounding points.
Parallel pipes in workshops or on trestle bridges should be connected to each other every 20m if they are 10cm apart; pipes less than 10cm apart or intersecting should be connected at intersections; the pipe and the metal frame should also be connected to each other at a distance of 10cm.
Both ends of the gas pipeline trunk and
molecular pipelines should be grounded; both ends of the pipeline trestle
should be connected to the upper pipeline, and should be connected to the
pipeline every 200m~300m; the trestle body should also be specially grounded.
Reliable grounding should be implemented
for storage of flammable gas, liquefied gas, liquid hydrocarbons, or other
storage tanks with fire hazard; for storage with a volume greater than 50m3,
grounding should be laid along its diameter and no less than 2 locations. Avoid
accidental damage or disconnection of the anti-static grounding wire and
grounding device during use; the flange of the pipeline must have good
conductivity.
All auxiliary equipment or tools such as
oil injection funnels, floating tank tops, workstations, scales, metal gauges,
etc. should be well grounded; when oil cans or drums are filled with oil, they
should be connected to the oil injection equipment and grounded.
Automobile oil sump should be equipped with
a metal chain, one end of the chain is fixedly connected to the oil sump
chassis, and the other end sags in contact with the ground. Before loading and
unloading oil, the tank truck should be connected to the storage equipment and
grounded; after loading and unloading, the oil pipe should be removed before
the jumper and grounding wire can be removed. All equipment for loading and
unloading oil must comply with the principles of "grounding first, then
connecting the oil pipe" and "disconnecting the oil pipe first, then
the ground wire". In solid and powder operations that may generate and
accumulate static electricity, calenders, glazing machines and various rollers,
mills, screens, mixers and other process equipment should be grounded. [2]
Conductive ground
The use of conductive ground is essentially
a grounding measure. The use of conductive ground can not only leak the static
electricity on the equipment, but also help to leak the static electricity
accumulated on the human body. Conductive ground is ground made of materials
with a resistivity of 1×108Ωm or less, such as concrete, conductive rubber,
conductive synthetic resin, conductive wood, conductive terrazzo, and
conductive ceramic tiles. Spray conductive paint on the insulating board. It
can also play the same role as the conductive ground. When using conductive
ground or conductive paint to spray the ground, the resistance between the
ground and the ground should not exceed 1MΩ, and the contact area between the
ground and the grounding conductor should not be less than 10cm2.
Insulator ground
For high-insulating materials that generate
and accumulate static electricity, that is, for liquid materials with a
resistivity of 1×109Ωm or more, even if they are in contact
with a grounded conductor, the static electricity changes little. This shows
that general grounding has little effect on eliminating static electricity on
high insulators. Moreover, for high-insulation materials that generate and
accumulate static electricity, it may increase the risk of sparks. Solid
materials with a resistivity of 1×107Ωm or less
and liquid materials with a resistivity of 1×108Ωm or less
are not easy to accumulate static electricity. Therefore, in order to make the
static electricity of the insulator leak faster, the insulator should be
grounded through a resistance of 1×106Ωm or a
little larger.
Shield
It uses a grounding body (shielding
conductor) to be placed close to the charged electrostatic body to increase the
capacitance of the electrostatic body to ground, reduce the electrostatic
potential, and reduce the risk of electrostatic discharge. It should be noted
that shielding cannot eliminate electrostatic charges. In addition, shielding
can reduce the possible discharge area, limit the discharge power, and prevent
electrostatic induction.
网络文化经营许可证:浙网文[2013]0268-027号|增值电信业务经营许可证:浙B2-20080224-1 2007-2024 Tradevv.com. All rights reserved.