U.S. patent number 3,877,898 [Application Number 05/394,612] was granted by the patent office on 1975-04-15 for electric dust collector.
This patent grant is currently assigned to Sumitomo Shipbuilding & Machinery Co., Ltd.. Invention is credited to Tsutomu Nomura, Masakazu Sakai.
United States Patent |
3,877,898 |
Nomura , et al. |
April 15, 1975 |
Electric dust collector
Abstract
An electrostatic precipitator to be provided directly on the
roof or top of the factory building, which is made light-weight by
making the dust collecting electrodes with light-weight materials,
such as polyvinyl chloride, fiber reinforced plastics, or the like
synthetic resin, aluminum treated to have the corrosion resistance,
duralmin, or the like light metals.
Inventors: |
Nomura; Tsutomu (Kamakura,
JA), Sakai; Masakazu (Hiratsuka, JA) |
Assignee: |
Sumitomo Shipbuilding &
Machinery Co., Ltd. (Tokyo, JA)
|
Family
ID: |
23559704 |
Appl.
No.: |
05/394,612 |
Filed: |
September 5, 1973 |
Current U.S.
Class: |
96/53; 266/147;
266/157 |
Current CPC
Class: |
B03C
3/78 (20130101); B03C 3/60 (20130101) |
Current International
Class: |
B03C
3/40 (20060101); B03C 3/60 (20060101); B03C
3/34 (20060101); B03C 3/78 (20060101); B03c
003/16 () |
Field of
Search: |
;55/122,124,126,128,129,154,155 ;110/119 ;98/42,43 ;266/15,31
;52/199,200 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
1,019,617 |
|
Feb 1966 |
|
GB |
|
1,037,701 |
|
May 1953 |
|
FR |
|
463,717 |
|
Aug 1928 |
|
DD |
|
509,404 |
|
Oct 1930 |
|
DD |
|
562,890 |
|
Oct 1932 |
|
DD |
|
140,696 |
|
Sep 1930 |
|
CH |
|
Primary Examiner: Nozick; Bernard
Attorney, Agent or Firm: Sughrue, Rothwell, Mion, Zinn and
Macpeak
Claims
What is claimed is:
1. An electrostatic precipitator overlying a vent hole within the
roof of a factory building, said precipitator comprising:
an open ended outer shell extending upwardly from said roof and
surrounding said vent hole for effecting flow of air from said
building through said shell by the thermal buoyancy of said
air,
a plurality of laterally spaced, vertical dust collecting
electrodes within said shell,
a series of vertical, discharging electrodes corresponding to said
collecting electrodes arranged at regular intervals, and
interleaved between said collecting electrodes and being connected
to an electric power supply,
said dust collecting electrodes being in planar sheet form and
formed of light weight material,
and sets of vertically spaced louvers positioned beneath said
electrodes with said louvers being inclined outwardly and
downwardly toward respective side walls of said shell relative to
the center line of the precipitator in order to prevent the washing
water from flowing into the work shop through the vent hole.
2. An electrostatic precipitator overlying a vent hole within the
roof of a factory building, said precipitator comprising:
an open ended outer shell extending upwardly from said roof and
surrounding said vent hole for effecting flow of air from said
building through said shell by the thermal buoyancy of said
air,
a plurality of laterally spaced, vertical dust collecting
electrodes within said shell,
a series of vertical, discharging electrodes corresponding to said
collecting electrodes arranged at regular intervals, and
interleaved between said collecting electrodes and being connected
to an electric power supply,
said dust collecting electrodes being in planar sheet form and
formed of light weight material,
said collecting electrodes being formed of synthetic resin sheets
having carbonaceous conductive material at least on the surfaces
thereof, and sets of vertically spaced louvers beneath said
electrodes to respective sides thereof, with said louvers being
inclined outwardly and downwardly towards opposed sidewalls of said
shell relative to the center line of said precipitator.
3. An electrostatic precipitator overlying a vent hole within the
roof of a factory building, said precipitator comprising:
an open ended outer shell extending upwardly from said roof and
surrounding said vent hole for effecting flow of air from said
building interior through said shell by the thermal buoyancy of
said air,
a plurality of laterally spaced, vertical dust collecting
electrodes within said shell,
a series of vertical, discharging electrodes corresponding to said
collecting electrodes arranged at regular intervals, and
interleaved between said collecting electrodes and being connected
to an electric power supply,
said dust collecting electrodes being in planar sheet form and
formed of synthetic resin having carbonaceous conductive material
at least on the surfaces thereof,
a water supply positioned centrally within said shell and beneath
said electrodes, and
sets of vertically spaced louvers positioned within said shell
beneath said water spray, with said louvers being inclined
outwardly and downwardly toward opposed sidewalls of said shell,
and
collector means on the inner periphery of the shell bottom for
removing water dripping from said louvers and the dust entrained
therein.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an electrostatic precipitator, and more
particularly to an electrostatic precipitator to be used for
various types of factories including, for example, basic oxygen
furnace, open hearth furnace, electric furnace, electrolytic
furnace, casting and molding plants, casting bed for the blast
furnace, wood working machines and bread making machines.
2. Description of the Prior Art
It is the usual practice to provide the precipitator on a factory
building to clean the waste gas from the building which may house a
basic oxygen furnace, an open hearth furnace, an electrolytic
furnace, molding and casting plants, or a casting bed for a blast
furnace.
The electrostatic precipitator is the most advantageous among
various types of dust collectors in view of the efficiency to
collect even the finest dusts, the investing and running costs and
the capacity to deal with the dusts.
The conventional electrostatic precipitator is provided isolated
from the factory building, and the waste gas is sucked from the
building through a flue duct, which connects the latter with the
precipitator, by a large capacity blower, as shown in FIG. 1.
Accordingly, the provision of the large sized flue duct and blower
requires much cost and space, and the blower generates noise and
vibration.
On the other hand, the fluorine gas generated from an aluminum
electrolyzing factory is removed by spraying fluorine gas absorber
(e.g. sodium hydroxide solution) through spraying nozzles provided
on the upper zone of the factory building. In such a case, the mist
of the fluorine gas unremoved is dispersed in and pollutes the
atmospheric air.
SUMMARY OF THE INVENTION
An object of this invention is to provide an improved precipitator
for removing the dusts generated from, for example the converter,
open hearth furnace, electric furnace, and molding and casting
plants.
Another object of this invention is to provide an improved
precipitator for sucking and removing the injurious gas generating
from an aluminum electrolyzing furnace.
We, the inventors, have discovered that the waste gas in the
factory building flows through the vent hole provided on the upper
part of the building with a flow rate of 2-3 m/sec (in rare case,
the flow rate reaches to 5 m/sec), even if an exhausting fan is not
provided. We have hit upon a plan for providing an electrostatic
precipitator on the upper part of the factory building on the basis
of this discovery.
The usual electrostatic precipitator, however, is made from iron
and accordingly too heavy to mount on the building (especially an
existing building). The total weight of the electrostatic
precipitator is composed of about 50 percent of outer shell, about
5 percent of discharging electrode and about 45 percent of dust
collecting electrode.
According to this invention, the dust collecting electrode, which
occupies about 45 percent of the total weight of the precipitator,
is made from hard polyvinyl chloride (P.V.C), fiber reinforced
plastic (F.R.P) or the like synthetic resin, aluminum, duralmin or
the like conductive light metal. The specific weight of the P.V.C.
or F.R.P. is about 1.4-1.5, while that of iron is 7.85, so that
weight of the dust collecting electrode made from the P.V.C. or
F.R.P. is reduced down to 1/5.6 - 1/5.2 of that made from iron. As
a result, the load to be applied on the outer shell of the
precipitator is decreased to reduce also much of the weight of the
outer shell which supports the dust collecting electrode. If
spraying means for spraying the gas absorber solution is
additionally provided below the electrostatic precipitator, which
is mounted on the upper part of the factory building, the dusts and
the injurious gases generated from the converter, open hearth
furnace and electric furnace are converted into the mists which
will be fully caught and removed by the upper precipitator.
Accordingly, the injurious gases and dusts generated from the
factory building can be removed effectively by providing a light
weight electrostatic precipitator according to this invention on
the upper part of the building without using an exhaust fan or
blower.
These and other objects and advantages of this invention may be
readily ascertained by referring to the following description and
appended drawings.
BRIEF EXPLANATION OF THE DRAWINGS
FIG. 1 is a schematic view of the conventional electrostatic
precipitator plant, and
FIGS. 2, 3, 4, 5 and 6 are various examples of the electrostatic
precipitator of this invention applied on the upper part of the
factory building wherein arrows indicate the directions of gas
flow.
PREFERRED EMBODIMENTS OF THE INVENTION
Referring to the FIG. 2, a vertical flow type electrostatic
precipitator 2 is provided on an upper part of a vent hole 5. A
louver 6 is provided on the vent hole 5 to direct the flow of the
waste gas and to prevent the washing water from flowing into the
work shop through the vent hole 5. The electrostatic precipitator 2
is composed of an outer shell 7 attached to a roof 1 of the
building, pluralities of dust collecting electrodes 8, and a series
of discharging electrodes 9 which are arranged in regular
intervals, assembled into a frame work and inserted between the
neighboring two dust collecting electrodes.
In a case that the dust collecting electrode 8 is made from the
synthetic resin and used in the dried state, the electrode must be
made conductive by coating the surface with the carbonaceous
material or by adding the latter preliminarily to the synthetic
resin. In order to introduce the waste gas into the vent hole 5 as
the constant flow, a small fan (not shown) for adjusting the
pressure difference between the atmospheric pressure and the
pressure in the factory building may be provided on the vent hole
5.
If washing nozzles 10 are provided on the louvers 6 and around the
vent hole 5 to prevent the after scattering of the dusts heaped on
the louvers 6, and the dusts are discharged by the washing liquid
from the louvers 6 through the roof 1 of the building, the
provision of a hopper for collecting the dusts can be omitted.
Referring to the FIG. 3, the vertical flow type electrostatic
precipitator 2 is provided on the side part of the vent hole 5. In
such a case, pluralities of adjustable dampers 11, are provided at
the inlet part of the precipitator 2 and adjustable in angle for
directing flow towards the latter. The amount of the gas to be
introduced into the precipitator is adjusted by these dampers 11,
and the gas can be supplied uniformly on the whole surface of the
dust collecting electrode 8. The gas outlet of the electrostatic
precipitator 2 is preferably provided on the upper part thereof so
as to retain the gas in the precipitator for a long period of time
and thereby to increase the dust collecting efficiency. Referring
to the FIG. 4, a horizontal flow type electrostatic precipitator 2
is provided on the vent hole 5, and pluralities of dampers 12 are
provided at the gas outlet part as an adjustable in angle. The
blowing of the wind and rain into the precipitator can be prevented
by adjusting the angles of the dampers 12.
Referring to the FIG. 5, an electrostatic precipitator 2, in the
case that the strength of the surrounding portion of the vent hole
5 is not enough to support the electrostatic precipitator, is
provided on the building roof 1 at a position a short distance from
the vent hole 5, and the waste gas is introduced into the
precipitator 2 by a guide member 13.
Referring to the FIG. 6, the electrostatic precipitator of this
invention is applied on the roof of an aluminum electrolyzing
factory building to remove the injurious gas. In such an example, a
spraying pipe 14 for spraying a gas absorbing agent, such as an
aqueous solution of sodium hydroxide, is provided between the
electrostatic precipitator 2 and the louver 6.
The injurious gas (fluorine gas in this case) rising through the
vent hole 5 is thus converted into a mist of uninjurious sodium
fluoride solution and caught by the precipitator 2.
As particularly described above, since the light-weight
electrostatic precipitator of this invention, whose dust collecting
electrode is made from a synthetic resin or light metal, is
directly provided on the upper part of the factory building, and
the waste gas generated from the factory building is introduced
into the precipitator as a natural flow, the provision of the flue
duct and large sized exhaust fan usually required becomes
unnecessary.
The synthetic resin used for the dust collecting electrode is
preferably hard, but a soft synthetic resin or a composite sheet
made from the hard and soft synthetic resins can be also
applicable.
* * * * *