Description
Acid Pickling Device
Technical Field
This invention relates to an acid pickling
device for washing and removing oxide scale, formed
on the surface of a strip plate, by acid pickling.
Background Art
In removing oxide scale formed on the surface
of a strip steel plate, common practice is to guide
this strip steel plate into an acid pickling tank
filled with an acid liquid by a guide roll, and cause
the strip steel plate to travel in the acid liquid,
thereby washing and removing the oxide scale on the
surface by means of the acid liquid. For this purpose,
an acid pickling device is available which comprises
two or more acid pickling tanks connected together,
the acid pickling tanks being filled with an acid
liquid of different acid concentrations, and in which
a strip steel plate is caused to travel in the acid
pickling tanks sequentially to remove oxide scale on
the surface of the strip steel plate reliably.
Fig. 8 is a schematic side view of a conventional
acid pickling device.
In the conventional acid pickling device, as
1

shown in Fig. 8, an acid pickling tank body 101 is
partitioned with a partition wall 102 into a first tank
103 and a second tank 104, and the first tank 103 and
the second tank 104 are almost the same in constitution.
That is, the first tank 103 and the second tank 104
are open upwards, and they are filled with acid liquids
Ll and L2, respectively, of different concentrations
for acid pickling of a strip steel plate S. A lid 105
is attached to the top of the acid pickling tank body
101 to form an inlet portion 106 in the first tank 103,
and an outlet portion 107 in the second tank 104. To
the inlet portion 106, an aerial deflector roll 108
and an immersion deflector roll 109 are attached. To
the outlet portion 107, an aerial deflector roll 110
and an immersion deflector roll 111 are attached. To
an intermediate portion, an aerial deflector roll 112
and immersion deflector rolls 113 are attached.
From a lower surface of the lid 105, ceiling
plates 115, 116 are suspended via engagingly stopping
portions 114 for immersion in the first tank 103 and
the second tank 104, respectively. From the ceiling
plates 115, 116, bottom plates 117, 118 are suspended
via connecting plates (not shown) located at both side
parts. On the lower surface of the ceiling plates 115,
116, many immersion guide rolls 119, 120 rotatable via
bearing portions are mounted along a direction of
travel of the strip steel plate S. On the upper surface
2

of the bottom plates 117, 118, many skids 121, 122 are
attached at positions opposed to the immersion guide
rolls 119, 120.
Thus, the strip steel plate S is guided by the
aerial deflector roll 108 and the immersion deflector
roll 109 at the inlet portion 106 into the acid liquid
L1 of the first tank 103, and travels, while being
guided, between the immersion guide rolls 119 and the
skids 121. At this time, oxide scale formed on the
surface of the strip steel plate S is washed with the
acid liquid Lx and removed thereby. Then, the strip
steel plate S is guided by the aerial deflector roll
112 and the immersion deflector roll 113 to pass over
the partition wall 102 and come into the acid liquid
L2 of the second tank 104. Then, the strip steel plate
S travels, while being guided, between the immersion
guide rolls 120 and the skids 122. On this occasion,
the oxide scale formed on the surface of the strip steel
plate S is washed with the acid liquid L2 and removed
thereby. Then, the strip steel plate S is guided by
the immersion deflector roll 111 and the aerial
deflector roll 110 at the outlet portion 107, and
delivered outside of the second tank 104.
Such a conventional acid pickling device is
disclosed, for example, in Japanese Unexamined Patent
Publication No. 5-78870.
With the foregoing conventional acid pickling
3

device, the acid pickling tank body 101 is divided into
the first tank 103 and the second tank 104 by the
partition wall 102 so that the acid liquids L1 and L2
do not mix. Because of this configuration, when the
strip steel plate S moves from the' first tank 103 to
the second tank 104, the strip steel plate S is guided,
in a bent shape, by the aerial deflector roll 112 and
the immersion deflector rolls 113. This plate S is
once pushed out of the first tank 103, and then entered
into the second tank 104 . At this time, a great bending
stress acts on the strip steel plate S, increasing the
tension of the strip steel plate S in the entire acid
pickling device, and consuming a high operating power.
Furthermore, when the strip steel plate S moves
from the first tank 103 to the second tank 104, it is
guided by the aerial deflector roll 112 and the
immersion deflector rolls 113. Thus, these rolls 112,
113 inevitably contact the acid liquid Lx. This
requires their constant mounting and dismounting for
maintenance, increasing the running cost.
The present invention has been accomplished in
an attempt to solve the above problems. Its object is
to provide an acid pickling device of a decreased cost,
and with an increased efficiency of acid pickling
treatment for a strip plate.
4

Disclosure of the Invention
The present invention is an acid pickling device
for acid pickling a strip plate by causing the strip
plate to travel in an acid pickling tank filled with
an acid liquid while guiding the strip plate by an
immersion guide roll and a skid, wherein two or more
of the acid pickling tanks are adjacent to each other
via a border site, and a liquid seal is provided at
the border site, the liquid seal having a cushion
nozzle for jetting the acid liquid in the acid pickling
tanks toward a surface of the strip plate travelling
in the acid pickling tanks.
Thus, the strip plate can be supported in a
straight form between the plural acid pickling tanks,
and a great bending stress does not act on the strip
plate. As a result, the tension of the strip plate in
the entire device can be decreased, and an increase
in the operating power can be prevented. Besides, no
rolls are present between the adjacent acid pickling
tanks. Maintenance of such rolls becomes unnecessary,
and the running cost can be reduced. Consequently, the
cost of the device can be decreased, and the efficiency
of acid pickling for the strip plate can be increased.
The present invention also concerns the acid
pickling device, wherein at the border site, a
partition wall is provided below the strip plate
travefling in the acid pickling tanks; a fixed skid is
5

provided on top of the partition wall at nearly the
same height as the height of the skid; and the cushion
nozzle is provided above the strip plate travelling in
the acid pickling tanks.
As noted above, a plurality of acid pickling
tanks are formed by partitioning one acid pickling tank
body with the partition wall, and the fixed skid and
the. cushion nozzle are provided above the partition
wall. Thus, the acid pickling tanks for acid pickling
the strip plate while supporting it easily in a
straight form can be formed.
The present invention also concerns the acid
pickling device, wherein at the border site, a
partition wall is provided below the strip plate
travelling in the acid pickling tanks; a lower cushion
nozzle is provided on top of the partition wall; and
an upper cushion nozzle is provided above the strip
plate travelling in the acid pickling tanks.
Thus, the acid liquid is jetted through the
cushion nozzles toward an upper surface and a lower
surface of the strip plate traveling in the acid
pickling tanks. As a result, the acid liquids in the
adjacent acid pickling tanks do not mix, and liquid
sealing can be achieved reliably.
The present invention also concerns the acid
pickling device, wherein the cushion nozzle has a first
jetting nozzle for jetting the acid liquid in one of
6

the adjacent acid pickling tanks, and a second jetting
nozzle for jetting the acid liquid in the other acid
pickling tank.
Thus, the acid liquid jetted from the first
jetting nozzle collides with the surface of the strip
plate, and then flows into one of the acid pickling
tanks, while the acid liquid jetted from the second
jetting nozzle collides with the surface of the strip
plate, and then flows into the other acid pickling tank.
Hence, the acid liquids in the acid pickling tanks do
not mix with each other.
The present invention also concerns the acid
pickling device, wherein the first jetting nozzle and
the second jetting nozzle are located in directions
in which a first jet of the acid liquid and a second
jet of the acid liquid jetted from the jetting nozzles
collide with each other.
As noted above, the first jet of the acid liquid
and the second jet of the acid liquid jetted from the
jetting nozzles collide, with the surface of the strip
plate, and also collide with each other. Thus, the
first jet and the second jet flow into their respective
acid pickling tanks without mixing with each other.
The present invention also concerns the acid
pickling device, wherein the cushion nozzle is
provided at nearly the same height as the height of
the immersion guide roll or the skid.
7

Thus, the strip plate can be transported
satisfactorily while being supported in a straight
form between the plural acid pickling tanks, without
a great bending stress acting on the strip plate.
The present invention also concerns the acid
pickling device, wherein an acid pickling tank lid for
covering the top of the acid pickling tanks is disposed
such that a central part of the lid is positioned below
the liquid level of the acid liquid in the acid pickling
tanks to cover a free surface of the acid liquid.
Thus, the surface area of the acid liquid in the
acid pickling tanks becomes narrower than in the
earlier technology. Hence, a loss of an acid due to
evaporation is decreased to ensure the reliable
washing and removal of oxide scale on the strip plate
by acid pickling.
The present invention also concerns the acid
pickling device, wherein the acid pickling tank lid
is provided with the immersion guide roll and the
cushion nozzle, and the skid is provided on a support
block installed at a bottom of the acid pickling tank.
Thus, the immersion guide roll, the cushion
nozzle, and the skid can be easily installed.
The present invention also concerns the acid
pickling device, wherein the acid pickling tank lid
is provided with the immersion guide roll and an upper
cushion nozzle, and the skid and a lower cushion nozzle
8

are provided on a support block installed at a bottom
of the acid pickling tank.
Thus, the immersion guide roll, the upper and
lower cushion nozzles, and the skid can be easily
installed.
The present invention also concerns the acid
pickling device, wherein supply pipes from the
respective acid pickling tanks are connected to the
cushion nozzle, and a liquid pump and a flow control
valve are mounted on each of the supply pipes.
Thus, the acid liquid can be fed from the acid
pickling tanks to the cushion nozzle by the liquid
pumps via the supply pipes . In this case, the jet flow
rate of the acid liquid from the cushion nozzle is
adjusted by the flow control valve, whereby an
appropriate amount of the acid liquid is jetted for
reliable liquid sealing.
Brief Description of the Drawings
Fig. 1 is a schematic side view of an acid
pickling device according to a first embodiment of the
present invention. Fig. 2 is a perspective view
showing a support structure for a skid. Fig. 3 is a
perspective schematic view of a liquid seal. Fig. 4
is a schematic view showing the actions of the liquid
seal. Fig. 5 is a schematic side view of an acid
pickling device according to a second embodiment of
9

the present invention. Fig. 6 is a schematic side view
of an acid pickling device according to a third
embodiment of the present invention. Fig. 7 is a
schematic side view of an acid pickling device
according to a fourth embodiment of the present
invention. Fig. 8 is a schematic side view of a
conventional acid pickling device.
Best Mode for Carrying Out the Invention
A first embodiment of the present invention will
now be described in detail by reference to the
accompanying drawings.
In an acid pickling device of the present
embodiment, as shown in Fig. 1, an acid pickling tank
body 11 is partitioned with a partition wall 12 into
a first tank 13 and a second tank 14, and the first
tank 13 and the second tank 14 are almost the same in
constitution. That is, the first tank 13 and the
second tank 14 are open upwards, and they are filled
with acid liquids L and L2, respectively, of different
concentrations for acid pickling of a strip steel plate
S. A lid 15 is attached to the top of the acid pickling
tank body 11 to form an inlet portion 16 in the first
tank 13, and an outlet portion 17 in the second tank
14. The lid 15 has an outer peripheral part fitted
liquid-tight to a receiver portion of the acid pickling
tank body 11, and has a central part forming a covering
10

portion 15a which is concave downwardly. The covering
portion 15a enters the acid liquids LL and L2 of the
first tank 13 and the second tank 14, and lies below
the liquid level of these acid liquids.
To the inlet portion 16, an aerial deflector roll
18 and an immersion deflector roll 19 are attached.
To the outlet portion 17, an aerial deflector roll 20
and an immersion deflector roll 21 are attached.
Between the first tank 13 and the second tank 14, a
liquid seal 22 is provided for inhibiting the mixing
of the acid liquids Lx and L2. Thus, the acid liquids
Lx and L2 of the first tank 13 and the second tank 14
in the acid pickling, tank body 11 have most of their
free surface covered with the covering portion 15a of
the lid 15. The mixing of the acid liquids Lx and L2
is inhibited by the liquid seal 22.
As shown in Figs. 1 and 2, on a lower surface
of the covering portion 15a of the lid 15, immersion
guide rolls 25a to 25d, 26a to 26d, which are immersed
in the first tank 13 and the second tank 14, are
rotatably mounted by a pair of (i.e., right and left)
bearing portions 23a to 23d, 24a to 24d made of a metal
(or resin, carbon or ceramic). This plurality of
immersion guide rolls 25a to 25d, 26a to 26d are
arranged parallel, with predetermined spacing, along
a direction of travel of the strip steel plate S. On
a bottom surface of each of the first tank 13 and the
11

second tank 14, a plurality of support blocks 27a to
27d, 28a to 28d are arranged parallel along the
direction of travel of the strip steel plate S. To the
top of the support blocks 27a to 27d, 28a to 28d, bottom
plates 29, 30 are fixed so as to connect the support
blocks 27a to 27d, 28a to 28d together. To an upper
surface of the bottom plates 29, 30, a plurality of
skids 31a to 31d, 32a to 32d are fixed at positions
opposed to the immersion guide rolls 25a to 25d, 26a
to 2 6d.
In the support blocks 27a to 27d, 28a to 28d,
acid liquid communication holes 33a to 33d, 34a to 34d,
through which the acid liquid L can flow, are formed.
In the bottom plates 29, 30, acid liquid passages 35a
to 35c, 36a to 36c, through which the acid liquids Lir
L2 can flow, are formed between the adjacent two of the
skids 31a to 31d, 32a to 32d downstream in the direction
of transport of the strip steel plate S. These acid
liquid passages 35a to 35c, 36a to 36c are each in a
slit, circular, or rectangular shape.
As shown in Figs. 1 and 3, in the liquid seal
22 provided at a junction between the first tank 13
and the second tank 14, a fixed skid 37 is attached
to an upper end of the partition wall 12 at nearly the
same height as the height of the respective skids 31a
to 31d, 32a to 32d. On a lower surface of the lid 15,
a cushion nozzle 38 for jetting the acid liquids Lx and
12

L, contained in the first tank 13 and the second tank
14 is provided opposite the fixed skid 37. This
cushion nozzle 38 is composed of a jetting chamber 39a
for the first tank 13 and a jetting chamber 39b for
the second tank 14, and slit nozzles 40a and 40b
extending obliquely therefrom, respectively. To the
jetting chamber 39a, a supply pipe 41a from the first
tank 13 is connected. On this supply pipe 41a, a liquid
pump 42a and a flow control valve 43a are mounted. To
the jetting chamber 39b, a supply pipe 41b from the
second tank 13 is connected. On this supply pipe 41b,
a liquid pump 42b and a flow control valve 43b are
mounted. The liquid pumps 42a, 42b and the flow
control valves 43a, 43b can be arbitrarily adjusted
by a control device (not shown).
In this case, as shown in Fig. 4, let the width
of the slit nozzles 40a, 40b be t, the angle of
inclination of the slit nozzles 40a, 40b be 9, the
distance between the slit nozzles 40a, 40b and the
strip steel plate S be h, the flow velocity of jets
Flf F2 be v, and the density of the acid liquids hir
L2 be p. Then, a static pressure, P, which occurs is
given by:

Thus, the strip steel plate S is guided by the
aerial deflector roll 18 and the immersion deflector
13

roll 19 of the inlet portion 16 into the acid liquid
L1 of the first tank 13, where the strip steel plate
S travels, while being guided, between the plurality
of immersion guide rolls 25a to 25d and the plurality
of skids 31a to 31d. On this occasion, oxide scale
formed on the surface of the strip steel plate S is
washed with and removed by the acid liquid L1. Then,
the strip steel plate S is passed between the fixed
skid 37 and the cushion nozzle 38 in the liquid seal
22, and led into the acid liquid L2 of the second tank
14 .
In the cushion nozzle 38 of the liquid seal 22,
the acid liquid Lx of the first tank 13 is guided into
the jetting chamber 39a through the supply pipe 41a,
and jetted from the slit nozzle 40a, by the action of
the liquid pump 42a. Whereas the acid liquid L2 of the
second tank 14 is guided into the jetting chamber 39b
through the supply pipe 41b, and jetted from the slit
nozzle 40b, by the action of the liquid pump 42b. The
jet FL from the slit nozzle 40a and the jet F2 from the
slit nozzle 40b collide with the surface of the strip
steel plate S, and also collide with each other,
thereby flowing toward the acid pickling tanks, which
they belong to, without mixing with each other. That
is, the jet FL flows toward the first tank 13, becoming
the acid liquid Ll . On the other hand, the jet F2 flows
toward the second tank 14, becoming the acid liquid
14

L2. Thus, the jets F1 and F2 do not mix, and liquid
sealing of the first tank 13 and the second tank 14
relative to each other can be performed, with the strip
steel plate S being supported by the jets Flf Fz and
the fixed skid 37.
The strip steel plate S, which has been guided
into the acid liquid L2 of the second tank 14 through
the liquid seal 22, travels, while being guided,
between the plurality of immersion guide rolls 26a to
26d and the plurality of skids 32a to 32d. On this
occasion, the oxide scale formed on the surface of ~he
strip steel plate S is washed with and removed by the
acid liquid L2. Then, the strip steel plate S is guided
by the immersion deflector roll 21 and the aerial
deflector roll 20 of the outlet portion 17 to the
outside of the second tank 14.
According to the acid pickling device of the
present embodiment, as described above, the liquid
seal 22 is provided between the first tank 13 and the
second tank 14 so as to be immersed in the acid liquid.
This liquid seal 22 is composed of the fixed skid 37
and the cushion nozzle 38. Hence, the strip steel
plate S can be supported in a straight form between
the first tank 13 and the second tank 14, and a great
bending stress does not act on the strip steel plate
S. As a result, the tension of the strip steel plate
S in the entire acid pickling device can be decreased,
15

and an increase in the operating power can be prevented.
Furthermore, the cushion nozzle 38 jets the acid
liquids Lx and L2 of the first tank 13 and the second
tank 14 toward the strip steel plate S, and the acid
liquids L,_ and L2 of the first tank 13 and the second
tank 14 are circulated, becoming free from stagnation.
Besides, no rolls are present between the first tank
13 and the second tank 14. Thus, roll maintenance
becomes unnecessary, and the running cost is reduced.
According to the acid pickling device of the
present embodiment, moreover, the covering portion 12a
in the central part of the lid 12 enters the acid liquids
LL and L2 in the first tank 13 and the second tank 14,
and lies below the liquid level of these acid liquids.
As a result, most of the free surface of the acid liquids
L: and L2 in the acid pickling tank 11 is covered with
the covering portion. Thus, the surface area of the
acid liquids L: and L2 in the first tank 13 and the second
tank 14 becomes smaller than in the earlier technology.
Hence, a loss of the acid due to evaporation is
decreased to ensure the reliable washing and removal
of the oxide scale on the strip steel plate S by acid
pickling.
In addition, as stated above, the covering
portion 12a of the lid 12 enters the acid liquid L in
the first tank 13 and the second tank 14, thereby
forcibly restraining the free surface of the acid
16

liquids LL and L2, so that the liquid level can be kept
constant. Besides, the acid liquid communication
holes 33a to 33d, 34a to 34d, through which the acid
liquids L: and L2 can flow, are formed in the support
blocks 27a to 27d, 28a to 28d. In the bottom plates
29, 30, the acid liquid passages 35a to 35c, 36a to
36c, through which the acid liquids LL, L2 can flow,
are formed. When the strip steel plate S travels,
while being guided, between the immersion guide rolls
25a to 25d, 26a to 26d and the skids 31a to 31d, 32a
to 32d, the acid liquids Lr and L2 follow the strip steel
plate S as it moves. As a result, a downstream flow
of the acid liquids Llt L2 in the traveling direction
of the strip steel plate S occurs. However, the acid
liquids Lw L2 do not wave, since their liquid level
is restrained by the covering portion 15a of the lid
15. This flow of the acid liquids Llf L2 passes through
the communication holes 33a to 33d, 34a to 34d and the
acid liquid passages 35a to 35c, 36a to 36c, and
circulates within the first tank 13 and the second tank
14. There is no stagnation of the acid liquids Llf L2,
and the liquid pressure is released. Hence, it does
not occur that the surface of the acid liquid L2 beside
the outlet portion 17 suddenly rises, causing overflow
of the acid liquid L2 to the outside. Moreover, the
liquid pressure in the first tank 13 and the second
tank 14 is released, and does not increase. Thus, the
17

strength of the lid 15 can be reduced.
Opposite the plural immersion guide rolls 25a
to 25d, 26a to 26d suspended from the lid 15, the plural
skids 31a to 31d, 32a to 32d are fixed to the bottom
plates 29, 30 on the plural support blocks 27a to 27d,
28a to 28d fixed to the bottom surface of the first
tank 13 and the second tank 14. Thus, there is no need
to suspend heavy materials from the lid 15, so that
the rigidity of the lid 15 can be decreased, and it
can be made light-weight.
Next, a second embodiment of the present
invention will be described in detail by reference to
the accompanying drawings. Members having the same
functions as those explained in the aforementioned
embodiment will be assigned the same numerals or
symbols, and overlapping explanations will be omitted.
In an acid pickling device of the present
embodiment, as shown in Fig. 5, an acid pickling tank
body 11 is partitioned with a partition wall 12 into
a first tank 13 and a second tank 14, and the first
tank 13 and the second tank 14 are filled with acid
liquids L: and L2, respectively, of different
concentrations for acid pickling of a strip steel plate
S . A lid 15 is attached to the top of the acid pickling
tank body 11. Between the first tank 13 and the second
tank 14, a liquid seal 51 is provided for inhibiting
the mixing of the acid liquids Lr and L2. On a lower
18

surface of a covering portion 15a of the lid 15,
immersion guide rolls 25a to 25d, 26a to 26d are mounted
which are immersed in the first tank 13 and the second
tank 14. On a bottom surface of each of the first tank
13 and the second tank 14, a plurality of support blocks
27a to 27d, 28a to 28d are arranged parallel. To the
top of the support blocks 27a to 27d, 28a to 28d, a
plurality of skids 31a to 31d, 32a to 32d are fixed
via bottom plates 29, 30.
In the liquid seal 51 provided at a junction
between the first tank 13 and the second tank 14, a
lower cushion nozzle 52 for jetting the acid liquids
Ll and L2 contained in the first tank 13 and the second
tank 14 is provided at an upper end of the partition
wall 12, at nearly the same height as the height of
the respective skids 31a to 31d, 32a to 32d. On a lower
surface of the lid 15, an upper cushion nozzle 53 is
provided opposite the lower cushion nozzle 52. To the
cushion nozzles 52, 53, supply pipes 41a, 41b from the
tanks 13, 14 are connected. On the supply pipes 41a
and 41b, liquid pumps 42a and 42b and flow control
valves 43a and 43b are mounted, respectively. The
cushion nozzles 52, 53 are each the same in
constitution as the cushion nozzle 38 of the first
embodiment, and their detailed descriptions are
omitted.
Thus, the strip steel plate S is guided from an
19

inlet portion 16 into the acid liquid Ll of the first
tank 13, where the strip steel plate S travels, while
being guided, between the immersion guide rolls 25a
to 25d and the skids 31a to 31d. On this occasion,
oxide scale formed on the surface of the strip steel
plate S is washed with and removed by the acid liquid
L:. Then, the strip steel plate S is passed through
the liquid seal 51, and led into the acid liquid L2 of
the second tank 14. In the liquid seal 51, the acid
liquid L-L of the first tank 13 is guided to the cushion
nozzles 52, 53, for jetting, through the supply pipe
41a by the action of the liquid pump 42a. Whereas the
acid liquid L2 of the second tank 14 is guided to the
cushion nozzles 52, 53, for jetting, through the supply
pipe 41b by the action of the liquid pump 42b. Jets
Fx and F2 from the cushion nozzles 52, 53 collide with
the surface and back of the strip steel plate S, and
also collide with each other, thereby flowing into the
acid pickling tanks, which they belong to, without
mixing with each other. Thus, liquid sealing of the
first tank 13 and the second tank 14 relative to each
other can be performed, with the strip steel plate S
being supported by the jets F:, F2. Then, the strip
steel plate S, which has been guided into the acid
liquid L2 of the second tank 14 through the liquid seal
51, travels, while being guided, between the immersion
guide rolls 26a to 26d and the skids 32a to 32d. On
20

this occasion, the oxide scale on the strip steel plate
S is washedwith and removed by the acid liquid L2. Then,
the strip steel plate S is delivered from an outlet
portion 17 .
Next, a third embodiment of the present
invention will be described in detail by reference to
the accompanying drawings.
In an acid pickling device of the present
embodiment, as shown in Fig. 6, an acid pickling tank
body 61 is partitioned with a partition wall 62 into
a first tank 63 and a second tank 64. The first tank
63 and the second tank 64 are filled with acid liquids
Lx and L2, respectively, of different concentrations
for acid pickling of a strip steel plate S. A lid 65
is attached to the top of the acid pickling tank body
61 to form an inlet portion 66 in the first tank 63,
and an outlet portion 67 in the second tank 64. The
lid 65 has a central part forming a covering portion
65a. The covering portion 65a enters the acid liquids
Lj and L2 of the first tank 63 and the second tank 64,
and lies below the liquid level of these acid liquids.
Thus, most of the free surface of the acid liquids L:
and L2 of the first tank 63 and the second tank 64 is
covered thereby. To the inlet portion 66, an aerial
deflector roll 68 and an immersion deflector roll 69
are attached. To the outlet portion 67, an aerial
deflector roll 70 and an immersion deflector roll 71
21

are attached. Between the first tank 63 and the second
tank 64, a liquid seal 72 is provided for inhibiting
the mixing of the acid liquids L1 and L2. Thus, the
mixing of the acid liquids Lx and L2 is inhibited by
the liquid seal 72.
On a lower surface of the covering portion 65a
of the lid 65, immersion guide rolls 75a to 75d, 76a
to 76d, which are immersed in the first tank 63 and
the second tank 64, are rotatably mounted by bearing
portions 73a to 73d, 74a to 74d. The immersion guide
rolls 75a to 75d, 76a to 76d are arranged parallel,
with predetermined spacing, along a direction of
travel of the strip steel plate S. On a bottom surface
of each of the first tank 63 and the second tank 64,
a plurality of support blocks 77a to 77d, 78a to 78d
are arranged parallel along the direction of travel
of the strip steel plate S. To the top of the support
blocks 77a to 77d, 78a to 78d, bottom plates 79, 80
are fixed so as to connect the support blocks 77a to
77d, 78a to 78d together. To an upper surface of the
bottom plates 79, 80, a plurality of skids 81a to 81d,
82a to 82d are fixed at positions opposed to the
immersion guide rolls 75a to 75d, 76a to 76d.
In the support blocks 77a to 77d, 78a to 78d,
acid liquid communication holes 83a to 83d, 84a to 84d,
through which the acid liquid L can flow, are formed.
In the bottom plates 79, 80, acid liquid passages 85a
22

to 85c, 86a to 86c, through which the acid liquids Llf
L2 can flow, are formed between the adjacent two of the
skids 81a to 81d, 82a to 82d downstream in the direction
of transport of the strip steel plate S. These acid
liquid passages 85a to 85c, 86a to 86c are each in a
slit, circular, or rectangular shape.
In the aforementioned liquid seal 72, a fixed
skid 87 is attached to an upper end of the partition
wall 62. On a lower surface of the lid 65, a cushion
nozzle 88 for jetting the acid liquids L: and L2
contained in the first tank 63 and the second tank 64
is provided opposite the fixed skid 87. To this
cushion nozzle 88, supply pipes 91a and 91b from the
respective tanks 63 and 64 are connected. On the
supply pipes 91a and 91b, liquid pumps 92a and 92b and
flow control valves 93a and 93b are mounted,
respectively. The cushion nozzle 88 is the same in
constitution as the cushion nozzle 38 of the first
embodiment, and its detailed explanation is omitted.
Thus, the strip steel plate S is guided by the
aerial deflector roll 68 and the immersion deflector
roll 69 of the inlet portion 66 into the acid liquid
L: of the first tank 63, where the strip steel plate
S travels, while being guided, between the plurality
of immersion guide rolls 75a to 75d and the plurality
of skids 81a to 81d. On this occasion, oxide scale
formed on the surface of the strip steel plate S is
23

washed with and removed by the acid liquid Lx. Then,
the strip steel plate S is passed between the fixed
skid 87 and the cushion nozzle 88 in the liquid seal
72, and led into the acid liquid L2 of the second tank
64 .
In the liquid seal 72, the acid liquids Lx and
L2 of the tanks 63 and 64 are fed into the cushion nozzle
88 through the supply pipes 91a and 91b by the action
of the liquid pumps 92a and 92b. Jets F1 and F2 from
the cushion nozzle 88 collide with the surface of the
strip steel plate S, and also collide with each other,
thereby flowing into the acid pickling tanks, which
they belong to, without mixing with each other. Thus,
liquid sealing of the first tank 63 and the second tank
64 relative to each other can be performed, with the
strip steel plate S being supported by the jets Fx, F2
and the fixed skid 87.
The strip steel plate S, which has been guided
into the acid liquid L2 of the second tank 64 through
the liquid seal 72, travels, while being guided,
between the plurality of immersion guide rolls 76a to
76d and the plurality of skids 82a to 82d. On this
occasion, the oxide scale formed on the surface of the
strip steel plate S is washed with and removed by the
acid liquid L2. Then, the strip steel plate S is guided
by the immersion deflector roll 71 and the aerial
deflector roll 70 of the outlet portion 67 to the
24

outside of the second tank 64.
According to the acid pickling device of the
present embodiment, as described above, the liquid
seal 72 is provided between the first tank 63 and the
second tank 64 so as to be immersed in the acid liquid.
This liquid seal 72 is composed of the fixed skid 87
and the cushion nozzle 88. Hence, the strip steel
plate S can be supported in a straight form between
the first tank 63 and the second tank 64, and a great
bending stress does not act on the strip steel plate
S. As a result, the tension of the strip steel plate
S in the entire acid pickling device can be decreased,
and an increase in the operating power can be prevented.
Furthermore, when the strip steel plate S travels,
while being guided, between the immersion guide rolls
75a to 75d, 76a to 76d and the skids 81a to 81d, 82a
to 82d, a downstream flow of each of the acid liquids
Lx, L2 in the travelling direction of the strip steel
plate S occurs as the strip steel plate S moves.
However, this flow of the acid liquids Lw L2 moves
downward through the acid liquid passages 85a to 85c,
86a to 86c, further passes through the communication
holes 83a to 83d, 84a to 84d, and is returned upstream
in the direction of transport of the strip steel plate
S. The acid liquid passages 85a to 85c, 86a to 86c are
located at positions just behind the site of passage
of the strip steel plate S between the immersion guide
25

rolls 75a to 75d, 76a to 76d and the skids 81a to 81d,
82a to 82d. Thus, agitation of the acid liquid L is
promoted, and the acid liquid L is circulated in the
acid pickling tank 31, so that there is no stagnation
of the acid liquid L.
Next, a fourth embodiment of the present
invention will be described in detail by reference to
the accompanying drawings. Members having the same
functions as those explained in the aforementioned
embodiment will be assigned the same numerals or
symbols, and overlapping explanations will be omitted.
In an acid pickling device of the present
embodiment, as shown in Fig. 7, an acid pickling tank
body 61 is partitioned with a partition wall 62 into
a first tank 63 and a second tank 64. The first tank
63 and the second tank 64 are filled with acid liquids
L: and L2, respectively, of different concentrations
for acid pickling of a strip steel plate S. A lid 65
is attached to the top of the acid pickling tank body
61. Between the first tank 63 and the second tank 64,
a liquid seal 96 is provided for inhibiting the mixing
of the acid liquids Lx and L2. On a lower surface of
a covering portion 65a of the lid 65, immersion guide
rolls 75a to 75d, 76a to 76d are mounted which are
immersed in the first tank 63 and the second tank 64.
On a bottom surface of each of the first tank 63 and
the second tank 64, a plurality of support blocks 77a
26

to 77d, 78a to 78d are arranged parallel. To the top
of the support blocks 77a to 77d, 78ato78d, a plurality
of skids 81a to 81d, 82a to 82d are fixed via bottom
plates 79, 80.
In the liquid seal 96 provided at a junction
between the first tank 63 and the second tank 64, a
lower cushion nozzle 97 for jetting the acid liquids
L1 and L2 contained in the first tank 63 and the second
tank 64 is provided at an upper end of the partition
wall 62. On a lower surface of the lid 65, an upper
cushion nozzle 98 is provided. The cushion nozzles 97,
98 are each the same in constitution as the cushion
nozzle 51 of the second embodiment, and their detailed
descriptions are omitted.
Thus, the strip steel plate S is guided from an
inlet portion 66 into the acid liquid L1 of the first
tank 63, where the strip steel plate S travels, while
being guided, between the immersion guide rolls 75a
to 75d and the skids 81a to 81d. On this occasion,
oxide scale formed on the surface of the strip steel
plate S is washed with and removed by the acid liquid
Lx. Then, the strip steel plate S is passed through
the liquid seal 96, and led into the acid liquid L2 of
the second tank 64. At this time, the acid liquids Llf
L2 of the tanks 63, 64 are guided to the cushion nozzles
97, 98, for jetting, through the supply pipes 91a, 91b
by the action of the liquid pumps 92a, 92b. Jets F:
27

and F2 from the cushion nozzles 97, 98 collide with the
surface and back of the strip steel plate S, and also
collide with each other, thereby flowing into the acid
pickling tanks, which they belong to, without mixing
with each other. Thus, liquid sealing of the first
tank 63 and the second tank 64 relative to each other
can be performed, with the strip steel plate S being
supported by the jets Flf F,. Then, the strip steel
plate S, which has been guided into the acid liquid
L2 of the second tank 64 through the liquid seal 96,
travels, while being guided, between the immersion
guide rolls 76a to 76d and the skids 82a to 82d. On
this occasion, the oxide scale on the strip steel plate
S is washedwith and removedby the acid liquid L2. _ Then,
the strip steel plate S is delivered from an outlet
portion 67.
In the foregoing embodiments, the acid pickling
tank body 11 was partitioned with the partition wall
12 into the first tank 13 and the second tank 14.
However, it is permissible to form the first tank 13
and the second tank 14 separately, connect them
together, and use their side walls as partition walls.
Alternatively, the interior of the acid pickling tank
body 11 may be partitioned into 3 or more tanks. In
the embodiments, the central part of the lid 15 was
depressed downward to form the covering portion 12a,
and the immersion guide rolls 25a to 25d, 26a to 26d
28

were mounted on the covering portion 12a. However, as
in the earlier technology, it is permissible to suspend
a ceiling plate and a bottom plate from a lower surface
of a box-shaped lid, and provide the immersion guide
rolls 25a to 25d, 26a to 26d and the skids 27a to 27d,
28a to 28d on these plates. Nor are the numbers of
these members restricted to those stated in the
embodiments.
Industrial Applicability
As described above, the acid pickling device of
the present invention immerses a strip plate in an acid
pickling tank to wash and remove oxide scale, formed
on the surface of the strip plate, by acid pickling.
This device is preferred for use in a surface treating
device for treating a continuously traveling strip
plate at a high speed.
29

Claims
1. An acidpickling device for acidpickling a strip
plate by causing the strip plate to travel in an acid
pickling tank filled with an acid liquid while guiding
the strip plate by an immersion guide roll and a skid,
wherein
two or more of the acid pickling tanks are
adjacent to each other via a border site, and a liquid
seal is provided at the border site, said liquid seal
having a cushion nozzle for jetting the acid liquid
in the acid pickling tanks toward a surface of the strip
plate trave|Ling in the acid pickling tanks.
2. The acid pickling device of claim 1, wherein at
the border site, a partition wall is provided below
the strip plate traveling in the acid pickling tanks;,
a fixed skid is provided on top of the partition wall
at nearly the same height as the height of the skid;
and the cushion nozzle is provided above the strip
plate travelling in the acid pickling tanks.
3. The acid pickling device of claim 1, wherein at
the border site, a partition wall is provided below
the strip plate travelling in the acid pickling tanks;
a lower cushion nozzle is provided on top of the
partition wall; and an upper cushion nozzle is provided
30

above the strip plate traveling in the acid pickling
tanks.
4 . The acid pickling device of claim 1, wherein the
cushion nozzle has a first jetting nozzle for jetting
the acid liquid in one of the adjacent acid pickling
tanks, and a second jetting nozzle for jetting the acid
liquid in the other acid pickling tank.
5. The acid pickling device of claim 4, wherein the
first jetting nozzle and the second jetting nozzle are
located in directions in which a first jet of the acid
liquid and a second jet o.f the acid liquid jetted from
the jetting nozzles collide with each other.
6. The acid pickling device of claim 1, wherein the
cushion nozzle is provided at nearly the same height
as the height of the immersion guide roll or the skid.
7. The acid pickling device of claim 1, wherein an
acid pickling tank lid for covering the top of the acid
pickling tanks is disposed such that a central part
of the lid is positioned below the liquid level of the
acid liquid in the acid pickling tanks to cover a free
surface of the acid liquid.
8. The acid pickling device of claim 7, wherein the
31

acid pickling tank lid is provided with the immersion
guide roll and the cushion nozzle, and the skid is
provided on a support block installed at a bottom of
the acid pickling tank.
9. The acid pickling device of claim 7, wherein the
acid pickling tank lid is provided with the immersion
guide roll and an upper cushion nozzle, and the skid
and a lower cushion nozzle are provided on a support
block installed at a bottom of the acid pickling tank.
10. The acid pickling device of claim 1, wherein
supply pipes from the respective acid pickling tanks
are connected to the cushion nozzle, and a liquid pump
and a flow control valve are mounted on each of the
supply pipes.
32
Dated this day of

An acid pickling tank body 11 is partitioned with a
partition wall 12 into a first tank 13 and a second
tank 14. The first tank 13 and the second tank 14 are
filled with acid liquids L1 and L2, respectively, of
different concentrations. A lid 15 is attached to the
top of the acid pickling tank body 11. On the lid 15,
immersion guide rolls 25a to 25d, 26a to 26d are mounted.
On the bottom surface of the first tank 13 and the second
tank 14, skids 31a to 31e, 32a to 32d are mounted via
support blocks 27a to 27e, 28a to 28d. A liquid seal
22 is provided which has a cushion nozzle 38 for jetting
the acid liquids L1 and L2 toward the surface of a strip
steel plate S traveling above the partition wall 12
for the first tank 13 and the second tank 14.