Steam generator cleaning apparatus control system

A control system for controlling a cleaning apparatus used for cleaning a steam generator includes a valve manifold which is controlled by a control console to direct a pressurized fluid to either a jetting outlet or a flushing outlet of the cleaning apparatus associated with the steam generator. The control console also controls a motor controller which defines the incremental distance that the jetting outlet is moved within the steam generator to clean different portions of the steam generator. The motor controller is remotely controllable from a platform control device so that the position of the jetting outlet can be changed by a person located on or near the steam generator during initial alignment and limit switch positioning. The control console also controls an evacuation circuit which extracts the fluid pumped into the steam generator and the sludge or other substances loosened therefrom. The control console still further controls the suction valves of a pump which provides the pressurized fluid so that the pressure can be extinguished upon either manual command or an automatically detected condition of the valves in the valve manifold. The pressure from the pump can also be extinguished by a remote controller functioning through the control console.

The present invention relates to a control system for controlling an 
apparatus used to clean a steam generator and more particularly, but not 
by way of limitation, to a control system for controlling the advancement 
of a sludge lance and the application of a pressurized fluid into a 
nuclear steam generator. 
Nuclear power plants typically utilize a steam generator having a vertical, 
inverted U-shaped tube bundle which carries the primary water directly 
heated by the nuclear reaction. Feedwater is carried by the shell side of 
the generator in contact with the tube bundle for generating steam to be 
directed to steam turbines. 
Among the maintenance problems that can arise in such nuclear power plants, 
some of the most potentially troublesome include sludge build-up in the 
steam generator, and particularly relate to concentrations of sludge which 
may accumulate on the tube sheet at the lower end of the tube bundle. 
This accumulation of sludge lowers steam production capacity, and the 
particles in the feedwater can cause abrasion of the U-tubes in the upper 
portions of the steam generator. These solids may even cause the steam 
turbine to foul if they are carried over in the steam. Also, since water 
chemistry cannot be controlled within the sludge piles, the steam 
generator tubes may corrode or dent. 
Several problems are caused by damaged tubes. Primary water from the tube 
bundle may leak into the feedwater that is to be turned into steam, thus 
creating a safety hazard. Plugged and sleeved tubes reduce the heat 
transfer area of the steam generator. As more time is required to be 
allotted to maintenance, more radiation exposure is required for 
maintenance personnel. Also, the steam generator's productive life span 
can be decreased significantly. 
Previous systems for high pressure water lancing of the spaces between the 
tube rows of the tube bundle of the steam generator have usually required 
the continuous presence of an operator at the steam generator hand holes. 
To remove the sludge from the steam generator, there is the need for a 
cleaning apparatus which can be used to remove the sludge from the steam 
generator and a control system for properly operating the cleaning 
apparatus to effect the cleansing of the steam generator. A suitable 
cleaning apparatus is disclosed in a copending U.S. patent application 
entitled "Sludge Lance Advancing Apparatus" which is assigned to the 
assignee of the present invention. A control system for controlling such a 
cleaning apparatus is provided by the present invention. 
A suitable control system for controlling the cleaning apparatus preferably 
can be operated in an automatic mode whereby the cleaning apparatus is 
moved and flowed to effect cleansing of the steam generator with a minimum 
of operator involvement. Although such a control system should be operable 
in an automatic mode, it should be capable of being operated in a manual 
mode in the event direct human control is necessary. 
The operator of such a control system should be able to remotely control 
the positioning of the cleaning apparatus to assist in properly setting up 
and aligning the cleaning apparatus in relationship to the steam 
generator. Remote control of fluid pressurization of the cleaning fluid 
should also be included in the control system so that the fluid can be 
depressurized in the case of an emergency. The control system should also 
include automatic controls for depressurizing the fluid in response to 
certain automatically detected conditions in the system. 
Such a control system should also be able to sense when the cleaning 
apparatus has moved to a predetermined limit so that further movement and 
fluid application are prevented. The system should also be able to control 
the direction of movement of the cleaning apparatus within the steam 
generator. 
So that the cleaning fluid and loosened sludge can be extracted from the 
steam generator, the control system should also include means for 
operating a suction pump associated with an outlet of the steam generator. 
The novel and improved control system provided by the present invention 
satisfies the aforementioned needs in providing suitable control of a 
cleaning apparatus, such as the cleaning apparatus disclosed in the 
copending U.S. patent application entitled "Sludge Lance Advancing 
Apparatus" and assigned to the assignee of the present invention. 
The control system of the present invention provides for either automatic 
or manual control of the cleaning apparatus. This automatic or manual 
control effects proper movement of the cleaning apparatus and the 
application of cleaning fluid into the steam generator. The system 
includes remote control means for manually indexing the positioning of the 
cleaning apparatus and remote control means for controlling the 
pressurization of the cleaning fluid. Fluid pressurization control is also 
automatically maintained in response to detected positions of valves of 
the control system of the present invention. 
The control system of the present invention also includes means for 
controlling the direction of movement of the cleaning apparatus in the 
steam generator and means for sensing the limits of travel of the cleaning 
apparatus. The control system also includes means for controlling a 
suction pump which extracts the cleaning fluid and loosened sludge from 
the steam generator. 
Broadly, the present invention provides a system for controlling an 
apparatus for cleaning a steam generator, which apparatus includes an 
advance mechanism for moving a jetting outlet within the steam generator 
and which apparatus also includes a flushing outlet and fluid source means 
for providing a fluid under pressure to either the jetting outlet or the 
flushing outlet. The system comprises valve manifold means for 
communicating the fluid from the fluid source means with a selectable one 
of the jetting outlet or the flushing outlet, advance mechanism control 
means for controlling the distance the advance mechanism moves the jetting 
outlet, and control means for controlling the valve manifold means and the 
advance mechanism control means. The control means includes timing means 
for providing a first signal to the valve manifold means to cause the 
valve manifold means to communicate the fluid with the jetting outlet and 
for providing a second signal to the valve manifold means and the advance 
mechanism control means to cause the valve manifold means to communicate 
the fluid with the flushing outletand to activate the advance mechanism 
control means to move the advance mechanism. The control means also 
includes monitor means for monitoring the state of the valve manifold 
means, and the control means further includes fluid source control means 
for causing the fluid source means to relieve the pressure on the fluid in 
response to the monitor means. 
The system also comprises limit means, associated with the advance 
mechanism, for providing a limit signa when the advance mechanism reaches 
a predetermined travel extremity. The advance mechanism control means 
includes means for providing a timing means control signal in response to 
the limit signal provided by the limit means. The control means includes 
means for preventing the timing means from providing the first and second 
signals in response to the timing means control signal. 
The system of the present invention also broadly comprises means for 
controlling the fluid source controlmeans from a location spaced from the 
control means and without regard to the state of the valve manifold means. 
The systemalso includes manual means for manually controlling the advance 
mechanism control means from a location spaced from the control means. 
Therefore, from the foregoing, it is a general object of the present 
invention to provide a novel and improved control system for a cleaning 
apparatus for cleaning a steam generator. Other and further objects, 
features and advantages of the present invention will be readily apparent 
to those skilled in the art when the following description of the 
preferred embodiment is read in conjunction with the accompanying 
drawings. 
FIG. 1 is a functional block diagram of the control system of the present 
invention. 
FIG. 2 is a functional block and schematic diagram showing the control 
system of the present invention in association with a more particularly 
described cleaning apparatus. 
FIG. 3 is a side elevational view of a particular advancing apparatus and 
sludge lance with which the control system of the present invention can be 
used. 
FIG. 4 is a schematic circuit diagram of the valve manifold control means 
of the preferred embodiment of the present invention. 
FIG. 5 is a schematic circuit diagram of the evacuation skid circuitry of 
the preferred embodiment of the present invention. 
FIG. 6 is a front elevational view of the control console of the preferred 
embodiment of the present invention. 
FIGS. 7A-7F are schematic circuit diagrams of the control console of the 
preferred embodiment of the present invention. 
FIG. 8 is a schematic circuit diagram of the motor controller means of the 
preferred embodiment of the present invention. 
FIG. 9A is an exterior view of the platform control box of the preferred 
embodiment of the present invention. 
FIG. 9B is a schematic circuit diagram of the platform control box of the 
preferred embodiment of the present invention. 
FIG. 10A is a schematic circuit diagram of the remote pressure kill 
controller means of the preferred embodiment of the present invention. 
FIG. 10B is a schematic diagram of a jumper connector used on the control 
console in place of the device shown in FIG. 10A.

With reference to the drawings, a control system constructed in accordance 
with the preferred embodiment of the present invention will be described. 
In FIG. 1, the control system of the present invention is shown associated 
with a steam generator 2 and a cleaning apparatus used for cleaning the 
steam generator 2. The cleaning apparatus includes an advance mechanism 4 
for moving a jetting outlet 6 into and out of the steam generator 2. The 
cleaning apparatus also includes a flushing outlet 8. The cleaning 
apparatus still further includes fluid source means, shown in FIG. 1 as a 
high pressure (HP) pump, for providing a fluid under pressure to either 
the jetting outlet 6 or the flushing outlet 8. This pressurized fluid is 
provided to either the jetting outlet 6 or the flushing outlet 8 via a 
valve manifold means 10 forming a part of the control system of the 
present invention. 
The cleaning apparatus with which the present invention is associated also 
includes a suction inlet 12 from the steam generator 2. The suction inlet 
12 is connected to an evacuation skid 14. 
The valve manifold means 10 and the evacuation skid 14 are controlled in 
response to control signals from a control console 16 forming another part 
of the control system of the present invention. The control console 16 
also provides control signals to a motor controller means 18 forming 
another part of the control system of the present invention. 
The motor controller means 18 directly controls the movement of the advance 
mechanism 4 and directly responds to a signal from the advance mechanism 4 
indicating a limit of travel has been reached by the advance mechanism 4. 
The motor controller means 18 is manually controllable in response to 
signals from a platform control box 20 forming another part of the control 
system of the present invention. 
The control console 16 is responsive to limit signals from the motor 
controller means 18 and to pressure kill signals from one or more remote 
pressure kill controller means 22 which forms still another part of the 
control system of the present invention. When a pressure kill signal is 
generated within the control console 16, it is provided to the high 
pressure pump of the cleaning apparatus to lift the suction valves of the 
pump, thereby depressurizing the fluid provided by the high pressure pump 
to the valve manifold means 10. 
With reference to FIGS. 2 and 3, a particular embodiment of the cleaning 
apparatus with which the present invention is contemplated to be used will 
be disclosed. This cleaning apparatus, including the particular embodiment 
of the advance mechanism shown in FIG. 3, is particularly described in the 
copending U.S. patent application entitled "Sludge Lance Advancing 
Apparatus" and assigned to the assignee of the present invention. 
In FIG. 2, the steam generator 2 is of a type used in a nuclear reactor as 
known to the art. The steam generator 2 includes an inverted U-shaped tube 
bundle shown generally in cross-section and designated by the numeral 24 
in FIG. 2. The tube bundle 24 includes a plurality of tubes, such as 
designated, for example, by the numeral 26, which are arranged in a 
plurality of parallel, equally spaced rows. 
In the following disclosure, for the purpose of illustration only, the rows 
of tubes 26 are designated as being the rows which are parallel to the 
length of the drawing sheet such as indicated by phantom lines 28, 30, 32 
and 34. These rows are equally spaced by a distance such as indicated by 
distance 36 between rows 32 and 34. 
The steam generator 2 includes an outer shell 38 having a pair of flanged 
hand holes 40 and 42 at diametrically opposite sides thereof. The lower 
ends of the tubes 26 extend through a tube sheet 44. An annular space 46 
is defined between tube bundle 24 and shell 38. The hand holes 40 and 42 
communicate with the annular space 46 which communicates with the upper 
surface of tube sheet 44. 
As seen in FIG. 2, at the central part of the tube bundle 24, there is a 
space where there are no tubes 26. This is the space between the legs of 
the inverted U-shaped tubes. This space defines a tube lane 48 which is 
diametrically aligned between the hand holes 40 and 42. 
Schematically shown at the hand hole 40 is the advance mechanism 4 which 
advances an elongated lance arm 50 carrying a jet head 52 on its outer end 
through the tube lane 48, which jet head 52 defines the jetting outlet 6 
in the embodiment of FIG. 2. 
Jets of fluid are ejected from the jet head 52 into the spaces between the 
tube rows, such as 28, 30, 32 and 34, to remove sludge material and the 
like which have collected between the tubes 26 on the tube sheet 44 and to 
move that material outward into the annular space 46. 
A pair of flushing fluid injection lines 54 and 56 are placed through hand 
hole 40 and are directed in opposite directions into the annular space 46. 
The flushing fluid injection lines 54 and 56 define the flushing outlet 8 
for the FIG. 2 embodiment. 
In the operation of the cleaning apparatus particularly illustrated in FIG. 
2, the apparatus is controlled to go through a cycle wherein it is indexed 
to a given position so that the nozzles of the jet head 52 are aligned 
with certain spaces between the tube rows, and then fluid is directed 
through the jet head 52 into the spaces between the tube rows to remove 
sludge material from between the tube rows and push it outward into the 
annular space 46. This continues for a period of thirty to sixty seconds 
in the preferred embodiment; however, other periods can be used. Then, the 
lancing or jetting cycle stops so that fluid flow to the jet head 52 is 
terminated. Thereafter, a flushing cycle begins wherein flushing fluid is 
directed to the flushing fluid injection lines 54 and 56 and travels in 
two semi-circular paths through the annular space 46 to wash the sludge 
around to a flushing fluid suction line 58 which is disposed through the 
second hand hole 42 defining the suction inlet 12 in the FIG. 2 
embodiment. Indexing of the jet head 52 to the next adjacent space between 
tube rows occurs during the flushing cycle. 
To extract the loosened sludge and fluid from the steam generator 2, the 
cleaning apparatus includes the evacuation skid 14 which is shown in FIG. 
2 to include a suction pump 60 of a type as known to the art. The suction 
pump 60 draws the fluid and sludge from the steam generator through the 
hand hole 42 and provides the extracted fluid and sludge as a discharge 
flow into a discharge line 62 and a surge tank 64 associated therewith. 
A booster pump 66 draws the fluid from surge tank 64 through a line 68 and 
directs it through a pair of filters 70 and 72 to a pressurizing pump 74 
which directs it through another filter 76 to the valve manifold means 10. 
The pumps 66 and 74 and the related elements provide the fluid source 
means designated in FIG. 1 as the high pressure (HP) pump. In the 
preferred embodiment, the pressurizing pump 74 is of a suitable type as 
known to the art, such as a Halliburton Services HT-400 pump. Such a pump 
includes suction valves which can be lifted to relieve the pressure on the 
fluid flowing therethrough. 
A flushing fluid supply line 78 connects the valve manifold means 10 to the 
flushing fluid injection lines 54 and 56. A lance fluid supply line 80 
connects the valve manifold means 10 to the lance 50 and particularly to 
the jet head 52 for supplying lancing or jetting fluid to the jet head 52. 
The cleaning apparatus shown in FIG. 2 can also include a second advance 
mechanism placed in the second hand hold 42. Typically, one advance 
mechanism will be extended only to approximately the center of the tube 
lane 48 so that it cleans one-half of the tube rows. Then, either that 
same advance mechanism will be moved to the second hand hole 42, or a 
second advance mechanism located at the hand hole 42 will be utilized. 
Although the disclosure of the present application describes the advance 
mechanism 4 as beginning near the hand hole 40 and then advancing forward 
towards the center of the tube lane 48, different cleaning patterns can be 
utilized which may, for example, begin at the center of the tube lane 48 
and move outward to the hand hole 40, or may include any combination of 
movements which may traverse the tube lane 48 several times for complete 
cleaning. 
Referring now to FIG. 3, a side elevational view of a particular embodiment 
of the advance mechanism 4 and elongated lance arm 50 will be described. 
The advance apparatus 4 of the FIG. 3 embodiment includes a frame 82. A 
lead screw 84 is rotatably disposed in the frame 82. 
An electric stepping motor 86 is connected to the frame 82. Drive means 88 
is connected between the stepping motor 86 and the lead screw 84 for 
rotating the lead screw 84 upon rotation of a shaft 90 of the stepping 
motor 86. 
A lance carrier 92 has an internal screw thread which engages the lead 
screw 84. The lance carrier 92 and lead screw 84 are so arranged and 
constructed that the lance carrier 92 is moved longitudinally relative to 
the lead screw 84 as the lead screw 84 is rotated relative to the lance 
carrier 92. A hand wheel means 96 is attached to an end shaft 98 of the 
lead screw 84. 
The advance mechanism 4 also includes a holder means 100, which is attached 
to the frame 82 by cap screws 102 and 104 for slidably receiving a portion 
of the lance 50 which is located forward of the lance carrier 92. 
The stepping motor 86 is mounted on a rearward side 106 of an upper part of 
a plate portion 108 of the frame 82 so that the shaft 90 of the stepping 
motor 86 is oriented substantially parallel to the lead screw 84 and 
extends forward through an opening of the plate portion 108. 
The drive means 88 includes a first pulley 110 attached to the shaft 90 of 
the stepping motor 86. It also includes a second pulley 112 attached to 
another end of the lead screw 84. The drive means 88 also includes a drive 
belt 114 which engages the first and second pulleys 110 and 112. 
Preferably, the drive belt 114 is a toothed drive belt and the pulleys 110 
and 112 are toothed pulleys so that a positive drive is provided between 
stepping motor 86 and the lead screw 84, thereby preventing any slippage 
of the stepping motor 86 relative to the lead screw 84. 
Also shown in FIG. 3 are limit switches 116 and 118 which detect and react 
to limit, and thereby define, the forwardmost and rearwardmost extremities 
of travel of the lance 50. This limitation occurs by providing suitable 
control signals to the motor controller means 18 when either of the limit 
switches 116 or 118 is actuated in response to engagement by the lance 
carrier 92. In the preferred embodiment, these control signals are 
provided as neutral or non-voltage signals in that during travel of the 
lance 50 between its forwardmost and rearwardmost extremities, a voltage 
is provided through the limit switches 116 and 118 to indicate that 
neither limit has been reached; but when an extremity is reached, then the 
signal is switched to a neutral potential to signify a limit has been 
reached. Therefore, in the preferred embodiment it can be said that the 
control signals are inhibiting signals which arise through the inhibiting 
of the voltage signals provided during movement of the lance 50 between 
its travel extremities. 
FIG. 3 also discloses that the illustrated lance 50 includes an internal 
thread 120 to which the jet head 52 is connected. Fluid flow is provided 
to the jet head 52 through the lance fluid supply line 80, a portion of 
which is illustrated in FIG. 3. 
With reference now to FIGS. 4-10B, the preferred embodiment of the control 
system for controlling the above-described cleaning apparatus will be more 
particularly described. 
The pressurized fluid from the pressurizing pump 74 is applied to either 
the flushing fluid supply line 78 or the lance fluid supply line 80 via 
the valve manifold means 10. The circuitry of the preferred embodiment of 
the valve manifold means 10 is shown in FIG. 4. 
The valve manifold means 10 includes a plurality of valves of suitable 
types as known to the art. In the preferred embodiment the valves include 
hydraulic valves controlled by pneumatic valve actuators which respond to 
air solenoids 122 shown in FIG. 4. FIG. 4 specifically discloses that 
there are four valves in the preferred embodiment, with each valve being 
associated with one of the four air solenoids 122a, 122b, 122c, and 122d 
shown in FIG. 4. Each of the valves is movable by its respective air 
solenoid 122 between an open position and a closed position. By 
appropriate control of the air solenoids 122, the pressurized fluid is 
communicated with the flushing fluid supply line 78, or the lance fluid 
supply line 80, or the corresponding lines associated with the second 
cleaning apparatus with which the preferred embodiment valve manifold 
means 10 can be associated. 
Actuation of the air solenoids 122 occurs in response to a suitable control 
signal provided by the control console 16 through an electrical connector 
124 of the valve manifold means 10. The control signal is coupled through 
the connector 124 and provided to a set of relays 126 having a plurality 
of relays 126a, 126b, 126c and 126d, each one of which is associated with 
a respective one of the air solenoids 122a, 122b, 122c, and 122d as shown 
in FIG. 4. When an appropriate control signal is received by one of the 
relays 126, the corresponding air solenoid is actuated to move the 
associated double-acting pneumatic valve actuator whereby the associated 
hydraulic valve is moved to open a flow path for the pressurized fluid 
from the pressurizing pump 74 to the selected one of the fluid supply 
lines. Movement of a pneumatic valve actuator causes movement of the 
respective one of a plurality of associated valve actuator switches 128a, 
128b, 128c, and 128d. 
Each valve actuator switch 128 can be placed either in a first position 
indicating that the associated valve is open or a second position 
indicating that the valve is closed. The signal provided by the placement 
of a respective one of the switches 128 in either of these positions is 
provided to the control console 16 via the connector 124. 
Electrical energy is provided to the valve manifold means 10 via a power 
supply line 130 which, in the preferred embodiment, is connectible to a 
standard 110-volt AC power supply. 
Associated ones of the air solenoids 122, relays 126 and valve actuator 
switches 128 are identified in FIG. 4 by the corresponding letters a, b, c 
or d. 
During normal operation of the preferred embodiment valve manifold means 
10, only one of the air solenoids 122a, 122b, 122c and 122d is open at any 
one time so that only a single flow of fluid is provided into the steam 
generator 2. 
Once the fluid has been provided to one of the supply lines and flowed into 
the steam generator 2, suction is then applied by means of the pump 60 to 
remove the fluid and loosened sludge from the steam generator 2. The pump 
60 forms a part of the evacuation skid 14 identified in FIG. 1. In the 
preferred embodiment the evacuation skid 14 has a control circuitry as 
shown in FIG. 5. 
The control circuitry of the evacuation skid shown in FIG. 5 includes a 
motor starter 132 which is a NEMA size 4 motor starter as known to the 
art. The motor starter 132 provides a starting current to a drive motor of 
the pump 60. In the preferred embodiment, the motor is a Louis-Allis 
60-horsepower motor. The motor starter 132 is controlled in response to 
actuation of a start switch 134 or a stop switch 136. 
The evacuation skid also includes a motor controller 138, such as a 
Louis-Allis MC-5 motor controller as known to the art. The motor 
controller 138 provides a control signal to the clutch of the pump 60 and 
its motor. Local control of the motor controller 138 is maintained by 
suitable actuation of a speed selector switch 140, a run switch 142, and a 
stop switch 144. Local control is maintained if a local/remote switch 146 
is placed in the position opposite that shown in FIG. 5. 
For the position of the remote/local switch 146 shown in FIG. 5, remote 
control of the speed can be effected from the control console 16 when it 
is connected to the evacuation skid circuitry via an electrical connector 
148. Remote control of the run and stop modes of operation of the motor 
controller 138 can also be effected from the control console 16 with 
suitable signals provided through an electrical connector 150. 
The evacuation skid circuitry shown in FIG. 5 also includes an overspeed 
protection circuit 152. 
The control console 16 includes a control panel 156 (FIG. 6) from which the 
control of the valve manifold means 10 and the evacuation skid 14 is 
performed. The control panel 156 also includes controls for controlling 
the motor controller means 18 and the suction valves of the pressurizing 
pump 74. The interface mechanisms by which an operator can control or 
provide direction to the control of the other devices will be described 
with reference to FIG. 6. 
A first portion of the control panel 156 includes means for placing the 
present invention in either an automatic or a manual mode and means for 
controlling the timing of the automatic operation of the present 
invention. This section includes an automatic/manual mode selector switch 
158 having lamps 160 and 162 associated therewith. The lamp 160 is 
illuminated when the switch 158 is placed in the manual mode position, and 
the lamp 162 is illuminated when the switch 158 is placed in the automatic 
mode position. The timing means of the present invention includes a 
jetting time selector switch means having a knob 164 for controlling the 
time period during which the pressurized fluid is provided to the lance 
fluid supply line 80. The timing means also includes a flushing time 
selector switch means having a knob 166 for controlling the time period 
during which the pressurized fluid is provided to the flushing fluid 
supply line 78. The knobs 164 and 166 are connected to potentiometers as 
shown in FIG. 7A. The timing means also includes a push-button switch 168 
for starting the cleaning operation with a jetting cycle and a push-button 
switch 170 for starting the cleaning operation with a flushing cycle. When 
a jetting cycle is being performed, a lamp 172 is illuminated; and when a 
flushing and indexing cycle is being performed, a lamp 174 is illuminated. 
A second section of the control panel 156 includes controls for directing 
the operation of the motor controller means 18. This control section 
includes a toggle switch 176 which determines the direction of travel 
along which the motor controller means 18 moves the lance 50. When the 
lance has been moved to one of its travel extremities, a limit lamp 178 is 
illuminated and the automatic timing signals provided in response to the 
setting of the controls 164 and 166 are overridden so that no further 
automatic jetting or flushing occurs. This limiting function can be 
overridden in response to the actuation of a push-button limit override 
switch 180. FIG. 6 shows that this portion of the control panel 156 also 
includes a lamp 182 which is illuminated when the motor control means 18 
has been instructed to index, or incrementally move, the lance 50. The 
number of such indexing, or incremental, steps is counted and displayed in 
a counter 184. Indexing occurs either automatically or manually as will be 
further described hereinbelow. Manual indexing occurs in response to 
actuation of a push-button switch 181. 
A third portion of the control panel 156 shown in FIG. 6 is the valve 
selector means for controlling which valves of the manifold valve means 10 
are to be utilized. The valves to be utilized are selected by 
appropriately setting toggle switches 186a, 186b, 186c, and 186d which are 
associated with the respectively lettered ones of the relays 126a-d and 
air solenoids 122a-d shown in FIG. 4. With the switches 186a-d positioned 
as shown in FIG. 6, the flushing and jetting valves associated with the 
supply lines 78 and 80, respectively, are the ones which will be actuated 
in response to the automatic control established in response to the 
setting of the controls 164 and 166 if the switch 158 is in the automatic 
mode position or in response to actuation of a manual valve select switch 
188 if the switch 158 is in the manual mode position. The switches 186b 
and 186d are associated with a second cleaning apparatus having a second 
advance apparatus not shown in the drawings, but which is contemplated to 
be associated with the hand hole 42 in a manner similar to that in which 
the advance mechanism 4 is associated with the hand hole 40. Once the 
switches 186a-d are properly set and control of the valve manifold means 
10 established, respective ones of lamps 190a, 190b, 190c and 190d are 
illuminated to indicate those valves which are open and respective ones of 
lamps 192a, 192b, 192c and 192d are illuminated to indicate which of the 
valves are closed. 
A fourth section of the control panel 156 includes controls for lifting the 
suction valves of the pressurizing pump 74. These controls include a 
pressure kill switch and lamp 194 which can be actuated at any time to 
lift the suction valves of the pump 74 and thereby relieve pressure from 
the fluid. A toggle switch 196 provides another means for lifting the 
suction valves of the pump 74; however, the switch 196 is operable only 
when the switch 158 is in the manual mode position. When the suction 
valves have been lifted, a lamp 198 is illuminated. 
The aforementioned control of the suction pump 60 which can be effected 
from the control panel 156 is achieved through proper actuation of the 
controls shown in the upper left-hand section of the control panel 156 
shown in FIG. 6. These controls include a push-button run switch 200, a 
push-button stop switch 202 and a potentiometer control knob 204 which 
controls a potentiometer used for remotely setting the speed at which the 
suction pump 60 is to operate. When the suction pump 60 is operating, a 
lamp 206 is illuminated; and when the pump is operating at an overspeed 
condition, a lamp 208 is illuminated. 
The control panel 156 also includes a pressure indicating meter 210 by 
means of which the magnitude of the pressure on the fluid flowing through 
the valve manifold means 10 is displayed. The control panel 156 also 
includes a time clock 212 and a power on/off switch 214. The switch 214 
has a fuse or other suitable circuit breaker means 216 associated 
therewith. 
With reference now to FIGS. 7A-7F, the aforementioned controls found on the 
control panel 156 will be schematically shown in association with their 
control circuits which are also associated with the control panel 156 and 
which also form parts of the control console 16. 
FIG. 7A discloses the preferred embodiment of the automatic/manual mode 
selector switch 158 and the associated lamps 160 and 162. FIG. 7A shows 
that the preferred embodiment switch 158 is a 10-pole, double-throw rotary 
switch. 
FIG. 7A also discloses the circuitry incorporating the control panel 
elements 164-174. These elements are included within the timing means for 
providing a jetting control signal to the valve manifold means 10 to cause 
the valve manifold means 10 to communicate the pressurized fluid with the 
selected lance fluid supply line and for providing a flushing and indexing 
control signal to the valve manifold means 10 to cause the valve manifold 
means 10 to communicate the pressurized fluid with the selected flushing 
fluid supply line. The flushing and indexing signal is also used to 
control the motor control means 18 to index the stepping motor 86 to move 
the lance 50. 
The timing means particularly includes in the preferred embodiment a 
jetting timer means 218 for providing the jetting control signal via an 
electrical conductor means 220 to the valve manifold means 10 to open the 
valve thereof which is associated with the lance fluid supply line 
selected by the switches 186a and 186b shown in FIGS. 6 and 7C. The 
jetting timer means includes a relay means 222 responsive to the setting 
of the control knob 164 and associated potentiometer for automatically 
periodically providing the jetting control signal over the conductor means 
220. The timing means also includes a flushing timer means 223 for 
providing the flushing and indexing control signal via an electrical 
conductor means 224 to the valve manifold means 10 to open the flushing 
valve of the flushing fluid supply line selected by either the switch 186c 
or or switch 186d. The signal is generated by another relay means 226 
which is responsive to the setting of the control knob 166 and its 
associated potentiometer. The flushing and indexing control signal 
generated by the relay means 226 is provided, when the switch 158 is in 
the automatic mode position, to an indexing means shown in FIG. 7B. This 
signal is provided over an electrical conductor means 228. 
The jetting timer means 218 and the flushing timer means 223 are operable 
when a power relay means 230 is actuated. The jetting timer means 218 or 
the flushing timer means 223 which is to provide its control signal first 
is selected by suitable actuation of either the start jet switch 168 or 
the start flush switch 170. Thereafter, control signals are alternately 
periodically generated to alternately periodically lance and flush the 
steam generator 2. 
When the lance 50 has been advanced by the motor controller means 18 to one 
of its travel extremities, a timing means control signal is provided by 
the motor controller means 18 and communicated to the control console 16, 
via an electrical conductor means 232, for deactivating a relay means 234 
so that the power relay means 230 and, thus, also the jetting timer means 
218 and the flushing timer means 223 are deactivated. This deactivation 
prevents the jetting and the flushing and indexing control signals from 
being provided over the conductor means 220, 224 and 228. In the preferred 
embodiment the timing means control signal is an inhibiting signal in that 
it occurs through the inhibiting of a voltage which is normally present on 
the conductor means 232 when a travel extremity has not been reached. 
It is to be noted that in the preferred embodiment the jetting timer means 
218 and the flushing timer means 223 operate in an EXCLUSIVE OR manner 
wherein one of the timer means is not providing its control signal when 
the other one is. This provides an alternating fluid flow in the steam 
generator 2 wherein either a jetting stream is provided from the jet head 
52 or a flushing stream is provided from the flushing heads 54 and 56. 
The indexing means which receives the flushing and indexing control signal 
from the flushing timer means 223 over the conductor means 228 is shown in 
FIG. 7B and identified by the reference numeral 236. The indexing means 
236 includes a relay means 237 and the manual indexing switch 181. 
When the mode selector switch 158 is in the automatic mode position, the 
indexing means 236 automatically provides an automatic indexing signal 
over electrical conductor means 238 and 240 to the motor controller means 
18 in response to a signal over the conductor means 228. 
When the mode selector switch 158 is in the manual position, the indexing 
means 236 provides a manual indexing signal over a conductor means 242 and 
the conductor means 240 when the switch means 181 is manually actuated. 
The indexing means 236 is constructed so that it is inhibited from 
providing an indexing signal to the motor control means 18 whenever the 
present invention is in a jetting cycle. That is, indexing in the 
preferred embodiment can occur only during a flushing cycle. When a 
flushing cycle is occurring and an indexing signal is provided over the 
conductor means 240, the motor controller means 18 indexes the lance 50 a 
distance, or increment, which has been preset in the motor controller 
means 18 as will be subsequently described. The direction of the indexing, 
or movement, of the lance 50 occurs in the direction as established by the 
setting of the direction switch 176 which is schematically illustrated in 
FIG. 7B. 
FIG. 7B also discloses an electrical connector 244 which is connectible 
with the motor controller means 18 as will be subsequently described. FIG. 
7B shows another electrical connector 246 which is connectible with the 
motor controller means 18 as will also be subsequently described. The 
aforementioned timing means control signal is provided to the conductor 
means 232 via the connector 246 as shown in FIG. 7B. This timing means 
control signal (i.e., the inhibition of the voltage normally present on 
the conductor means 232 in the preferred embodiment) can be overridden by 
manual actuation of the limit override switch 180. When the override 
switch 180 is actuated, the relay 234 is activated (i.e., a voltage is 
applied to the conductor means 232) so that the timing means is not 
deactivated. 
FIG. 7B also shows that the connector 246 has the limit indicator lamp 178, 
the indexing lamp 182, and the indexing counter 184 associated therewith. 
FIG. 7C discloses the portion of the control console 16 directly associated 
with the valve manifold means 10. This association is effected via an 
electrical connector 248 which is constructed for mating engagement with 
the connector 124 shown in FIG. 4. 
This portion of the control console 16 includes the manifold valve selector 
switches 186a-d and the associated manual valve select switch 188. The 
switches 186a-d are logically arranged in an EXCLUSIVE OR manner so that 
only one jet line or one flush line can be opened at any one time. 
Also shown in FIG. 7C to be associated with the connector 248 are the 
manifold valve status/position indicator lamps 190a-d and 192a-d. 
Also included in the portion of the control console 16 shown in FIG. 7C is 
a monitor means for monitoring the status (i.e., the open or closed 
position) of the valves of the valve manifold means 10. The monitor means 
is shown particularly as a manifold valve position logic circuit means 250 
having eight relays 252a, 252b, 252c, 252d, 254a, 254b, 254c, and 254d 
which are used to indicate, in response to signals from the valve actuator 
switches 128a, 128b, 128c, and 128d, whether respective ones of the valves 
of the valve manifold means 10 are in their open or closed positions. The 
relays 252a-d indicate the open status, and the relays 254a-d indicate the 
closed status. 
Through the operation of the valve position logic circuit means 250, those 
combinations of signals which would cause simultaneous jetting and 
flushing in the steam generator 2 are inhibited. This inhibition is 
achieved by generating signals which cause the suction valves of the pump 
74 to be maintained in an open position until only one jet valve is open 
and all flush valves are closed or until only one flush valve is open and 
all jet valves are closed. The suction valves are also lifted when all of 
the valves are closed (in the preferred embodiment this is detected by 
monitoring the valve open signals to determine if any valves are open; if 
not, it is presumed that all are closed). This control is maintained only 
when the switch 158 is placed in the automatic mode position; however, the 
circuit 250 provides an inhibiting signal if all of the valves are closed 
when the switch 158 is in the manual mode position. The circuit means 250 
signal indicating that all the valves are closed is provided over an 
electrical conductor means 256 shown in FIGS. 7C and 7D. The circuit means 
250 signal indicating that only one jet or flush valve is open, thereby 
signifying the suction valves should be closed, is provided over a 
conductor means 257. 
The circuitry for interfacing with the suction valve circuitry of the pump 
74 is shown in FIG. 7D. This interfacing circuitry and the signals to 
which it responds provides the means for controlling the fluid source 
including the pump 74 in the preferred embodiment. Connection with the 
pump 74 is made by means of an electrical connector 258. Connected to the 
connector 258 is a relay means 260 having the conductor means 256 
connected thereto. The conductor means 256 provides one portion of a 
series circuit which also includes the logic circuit 250 and electrical 
connectors 260, 262, and 264 which are used for connecting with respective 
ones of the remote pressure kill controller devices generally identified 
in FIG. 1 by the reference numeral 22. Also associated with the relay 260 
are the pressure kill switch 194, which includes a switch mechanism 194a 
and a lamp 194b, and the suction valve lifted indicator lamp 198. 
The relay means 260 and the suction valve lift circuitry associated 
therewith maintain the suction valves raised when all the valves of the 
valve manifold means 10 are closed, or when a jet and a flush valve of the 
valve manifold means 10 are both open at the same time, or when there has 
been a loss of electrical power at either the control console 16 or the 
valve manifold means 10, or when there has been a loss of air pressure at 
the valve manifold means 10, or when the control console 16 and the valve 
manifold means 10 have become disconnected. The relay means 260 operates 
in an electrically activated state to hold the suction valves closed 
during normal operating conditions so that a "dead man" operation is 
achieved wherein power must be maintained in the control system for the 
pump 74 to pump the fluid. 
The suction valve relay 260 is also responsive to the signal provided by 
the logic circuit 250 over the conductor means 257 when the mode selector 
switch 158 is in the automatic mode position (see FIGS. 7A, 7C and 7D). 
When the switch 158 is in the manual mode position, the conductor means 
257 is disconnected from the suction valve relay 260 and, in its place, 
there is connected the manual suction valve lift switch 196 as shown in 
FIG. 7A. The switch 196 is collocated with the mode selector switch 158 in 
the sense that they both are located on the control panel 156. 
FIG. 7E discloses the circuitry of the control console 16 which provides 
the remote control of the suction pump 60. This circuitry includes the 
control panel elements 200-208 described hereinabove. The elements 200, 
202, 206, and 208 are connected to an electrical connector 266 which is 
constructed for mating engagement with the connector 150 shown in FIG. 5. 
The control knob 204 and related potentiometer shown in FIG. 7E are 
connected to an electrical connector 268 which is constructed for mating 
engagement with the connector 148 shown in FIG. 5. When the connectors 150 
and 266 and the connectors 148 and 268 are connected, and when the switch 
146 is placed into the position shown in FIG. 5, both run/stop control and 
speed control of the suction pump 60 can be achieved from the control 
panel 156. 
FIG. 7F discloses the schematic diagram of the circuitry incorporating the 
pressure indicator 210 and the clock 212. The pressure indicator 210 is 
connected, by a suitable electrical connector 270, to a pressure 
transducer (not shown) located in the preferred embodiment at the valve 
manifold means 10. 
With reference to FIG. 8, the motor controller means 18 will be described. 
The motor controller means 18 can be more broadly referred to as an 
advance mechanism control means for controlling the distance the advance 
mechanism 4 moves the jetting outlet 6. More particularly, the motor 
controller means 18 controls the incremental distance that the stepping 
motor 86 moves the lance 50 and the jet head 52 connected thereto. 
The motor controller means 18 includes means for providing the timing means 
control signal (i.e., for the preferred embodiment the neutral or 
non-voltage signal resulting from the inhibition of the voltage normally 
applied to the conductor 232 when the lance is not at either travel 
extremity) to the control console 16 to control the relay 234 to terminate 
the operation of the timing means shown in FIG. 7A. This timing means 
control signal arises in response to the limit signal received from the 
advance mechanism 4, which limit signal in the preferred embodiment is the 
inhibition of a voltage, or in other words the switching from a 
non-neutral potential to a neutral potential, which occurs when the lance 
carrier 92 engages one of the limit switches 116 or 118. The timing means 
control signal is communicated to the control console 16 through an 
electrical connector 272 constructed for mating engagement with the 
connector 246 shown in FIG. 7B. This signal is provided to the connector 
272 over an electrical conductor means 274 extending from a relay means 
276 forming another part of the motor controller means 18. 
The motor controller means 18 is also coupled to the control console 16 
through an electrical connector 278 which is constructed for mating 
engagement with the connector 24 shown in FIG. 7B. 
The motor controller means 18 is also associated with electrical connectors 
280 and 282 which provide for coupling with the platform control box 20 
shown in FIGS. 1 and 2 and more particularly described hereinbelow with 
reference to FIGS. 9A-9B. When the motor controller means 18 is connected 
to the platform control box 20 through the connectors 280 and 282 and 
control is provided from the platform control box, a lamp 284 is 
illuminated. 
The motor controller means 18 also includes electrical connectors 286 and 
288 which connect with matching connectors (not shown) on the stepping 
motor 86. 
FIG. 8 also shows that the motor controller means 18 includes a preset 
indexer 290, such as a type SP 155A preset indexer of Superior Electric 
Company of Bristol, Conn. The preset indexer 290 is operable in a manner 
as known to the art to establish a preset indexing length by which the 
stepping motor 86 will move the lance 50 in response to an indexing 
command from the control console 16. 
The motor controller means 18 also includes a power circuit means 292 
having a lamp 294 associated therewith for indicating when the motor 
controller means 18 has power applied thereto. 
The motor controller means 18 also includes fans 296 for cooling the 
components thereof. 
With reference to FIGS. 9A-9B, the preferred embodiment of the platform 
control box 20 will be described. The platform control box 20 provides 
means for manually controlling the motor controller means 18 from a 
location spaced from the control console 16 and the motor controller means 
18. The platform control box 20 is used in the contemplated preferred 
embodiment of use at the steam generator 2 platform for setting the limit 
switches and for performing other manual operations during the set up and 
alignment of the advance mechanism 4. In the preferred embodiment the 
platform control box 20 can control the motor controller means 18 only 
when the control console 16 is in the manual mode as set by the mode 
selector switch 158. 
As shown in FIG. 9A, the platform control box 20 includes a housing 298 
having a push-to-index switch 300 and a hold-to-index-in switch 302 
mounted therein. The housing 298 also has a lamp 304 mounted therein for 
indicating when the advance mechanism 4 has moved the lance 50 to one of 
its limits of travel. The housing 298 is connected to the motor controller 
means 18 by means of an electrical connector 306 and an electrical 
connector 308 and the associated cabling shown in FIG. 9A. The connector 
306 is constructed for mating engagement with the connector 280 shown in 
FIG. 8, and the connector 308 is constructed for mating engagement with 
the connector 282 shown in FIG. 8. 
FIG. 9B discloses a schematic circuit diagram of the platform control box 
20. 
With reference to FIG. 10A, the preferred embodiment of one device of the 
remote pressure kill controller means 22 will be described. The device 
includes a switch 310 connected to an electrical connector 312 which is 
constructed for mating engagement with any one of the connectors 260, 262 
or 264 shown in FIG. 7D. When the connector 312 is connected to one of the 
connectors 260, 262, or 264, opening of the switch 310 will cause the 
suction valves of the pump 74 to be lifted if the connector 258 shown in 
FIG. 7D is connected to the pump 74. This control of the suction valves 
occurs regardless of the state of the manifold 10 valves or of the valve 
position logic means 250. It is contemplated that one or more of these 
devices of the remote pressure kill controllers 22 will be placed at 
locations where high pressure lines are monitored so that if a break in a 
line occurs, the switch 310 of that particular device can be actuated to 
lift the suction valves of the pressurizing pump 74. 
If a device of the means 22 is not to be connected to each of the 
connectors 260, 262 and 264, then a jumper connector 314 (FIG. 10B) must 
be connected thereto to maintain electrical continuity through the series 
circuit in which the connectors 260-264 are disposed. 
The individual electrical components shown in the above-described drawings 
are of suitable types known to the art. Furthermore, the specific 
circuitry shown in the drawings forming part of the specification are not 
to be taken as limiting the scope of the present invention to such 
specific embodiment. 
In the operation of the preferred embodiment, the system is connected as 
shown in FIGS. 1 and 2 with the previously described connectors being 
coupled as appropriate. The respective components are energized as 
appropriate. 
Alignment of the lance 50 in the steam generator 2 and setting of the limit 
switches is done in part using the platform control box 20. 
The system is preset by placing the switch 146 of the evacuation skid shown 
in FIG. 5 in either the local or remote position as desired. The speed at 
which the suction pump 60 on the evacuation skid is to operate is set via 
the potentiometer and control 140 (FIG. 5) or the potentiometer and 
control 204 (FIG. 7E) depending upon the setting of the switch 146. 
On the control panel 156, the mode selector switch 158 is set in the 
appropriate position for the desired mode of operation. The time periods 
for the jetting and flushing cycles are set by appropriately manipulating 
the jetting time control knob 164 and the flushing time control knob 166, 
respectively. The direction-of-movement switch 176 is placed in the 
appropriate setting. The valves of the valve control means 10 which are to 
be used are selected by appropriate positioning of the switches 186a-d 
also contained on the control panel 156. 
To preset the motor controller means 18, the indexer 290 is preset as known 
to the art. 
Once the system has been aligned and preset, control of the cleaning 
process can commence. If the automatic mode has been selected via the 
switch 158, the suction pump 60 is actuated via the run switch 200 
contained on the control panel 156. Automatic control of the injection of 
fluid into the steam generator 2 and the movement of the lance 50 is 
initiated by actuating either the start jet switch 168 or the start flush 
switch 170 depending upon which cycle is to be performed first. Operation 
proceeds automatically with the timing means shown in FIG. 7A periodically 
switching the control signals between the selected jet valve and flush 
valve of the valve manifold means 10. 
Automatic operation continues until the lance 50 has been moved to one of 
its limits of travel (or until the mode selector switch 158 has been 
switched to the manual position or the control system has been 
de-energized). When a limit of travel is reached, the particular limit 
switch which is engaged provides the limit signal (i.e., the neutral 
potential resulting from the inhibiting of, or switching from, the 
non-neutral potential in the preferred embodiment) to the motor controller 
means 18 which in turn provides the timing means control signal (which is 
the neutral signal from the engaged limit switch connected to the 
conductor means 232 via the conductor means 274 in the preferred 
embodiment) to the relay 234 shown in FIG. 7A. When this preferred 
embodiment neutral signal is received by the relay 234, the relay 234 is 
deactivated which in turn deactivates the timing means so that no further 
jetting, flushing or indexing occurs. However, the timing means control 
signal (i.e., the neutral signal in the preferred embodiment) provided by 
the motor controller means 18 can be overridden (i.e., a non-neutral 
signal can be applied in the preferred embodiment) by proper actuation of 
the switch 180 shown in FIGS. 6 and 7B. 
During the automatic control of the cleaning operation, pressurized fluid 
will be continuously applied by the pump 74 unless the suction valve 
control circuit directs otherwise. In the automatic mode the suction valve 
control means will lift the suction valves of the pump 74 if the switch 
194 on the control panel 156 is actuated; however, no such suction valve 
lifting will occur if the switch 196 of the control panel 156 is actuated 
because the switch 196 is operational only when the system is in the 
manual mode. The suction valves will also be lifted if a remote kill 
signal is provided from one or more of the devices of the pressure kill 
controller means 22. The suction valves will also be lifted if the valve 
logic position circuit means 250 detects that all the manifold valves are 
closed or it detects that more than one of the valves is open at any one 
time. The suction valves will also be lifted if power is lost. 
If the manual mode of operation has been selected by the proper placement 
of the switch 158, the operation commences by actuating the suction pump 
via the switch 200. The jet or flush cycle is then selected by appropriate 
manipulation of the switch 188. Whenever the flush cycle has been selected 
by means of the switch 188, the lance 50 can be manually indexed by 
suitable actuation of the manual index switch 181, which switch 181 only 
functions during the flush cycle as determined by the setting of the 
switch 188. In the manual mode the suction valves of the pump 74 are 
lifted if the switch 194 is actuated, or if the switch 196 is actuated, or 
if one of the remote pressure kill devices 22 is actuated, or if the valve 
logic circuit means 250 detects that all of the valves of the manifold 
valve means 10 are closed, or if power is lost. 
In either the automatic mode of operation or the manual mode of operation, 
the number of times the lance 50 has been indexed or incremented is 
displayed in the counter 184. The pressure provided to the valve manifold 
means 10 by the pump 74 is displayed played in the pressure indicator 210. 
The time of day is displayed by means of the clock 212. 
Thus, the present invention is well adapted to carry out the objects and 
attain the ends and advantages mentioned above as well as those inherent 
therein. While a preferred embodiment of the invention has been described 
for the purpose of this disclosure, numerous changes in the construction 
and arrangement of parts can be made by those skilled in the art, which 
changes are encompassed within the spirit of this invention as defined by 
the appended claims.