Improved Method of and Apparatus for Lessening or Preventing Incrustation, Corrosion, and Pitting in Steam Generators and Apparatus for Imparting Heat to. Water, not with Electric Lighting Apparatus.
Year: 1892

page_text: Date of Application, 29th Mar., 1892
Complete Specification Left, 27th Dec., 1892-Accepted, 18th Feb., 1893
PROVISIONAL SPECIFICATION.
Improved Method of and Apparatus for Lessening or Preventing
Incrustation, Corrosion, and Pitting in Steam Generators and
Apparatus for Imparting Heat to. Water, which Invention 'oan be
applied in connection or not with Electric Lighting Apparatus.
We, JAMES BENNETT, Electrician, and JOHN TELLEFSEN, Ship Broker, both
of Merchants Exchange, Cardiff, in the County of Glamorgan, do hereby.declare
the nature of this invention to be as follows:-
This invention has reference to an improved method of and apparatus for
lessening or preventing incrustation corrosion and pitting in steam generators and
apparatus for imparting heat to water, such for example as what are known as feed
water heaters or evaporators. For this purpose alternately a continuous current of
electricity is caused to flow from an electric generator to an insulated conductor
(hereinafter called for distinction the insulated electrode) and thence to the shell of
the steam generator or other heating apparatus (hereinafter included in the
expression boiler) through the water therein, whereby the said insulated electrode
and boiler shall become charged after the manner of the electrodes in a secondary
cell, and then the boiler and insulated electrode are caused to be short circuited
through a separate conductor so that a secondary current is caused to flow in an
opposite direction to that first mentioned from the boiler through the water therein
to the insulated electrode, these operations being repeated alternately and at short
intervals.
In conjunction with a suitable source of electricity such as a galvanic battery, or
a dynamo, and one or more plates or electrodes arranged to dip into the water in
the boiler but insulated from the boiler shell we employ an apparatus comprising a
movable contact arranged to work between two other contacts, and means for
automatically operating the movable contact at short intervals, the arrangement
being such that the said movable contact when in one position, connects for a
suitable time the boiler shell and the insulated electrode to opposite poles of the
électric generator so as to complete the circuit of the electric generator through the
water in the boiler, and in another position breaks this circuit so as to cut out
the electric generator and electrically connect for a suitable time the said boiler and
insulated electrode through a separate conductor.
Such an apparatus can be constructed in various forms.
In one arrangement the movable contact is in the form of a switch lever mounted
upon but insulated from a pin and arranged to work between two insulated spring
contacts or brushes one of which, when the apparatus is in use, is connected with
one pole of an electric generator and the other with the boiler shell, the switch
lever being itself connected with the insulated electrode. A cam fixed upon a shaft
and driven through worm or other suitable gearing from a motor, it may be from
the armature shaft of the dynamo, serves by acting at the required times upon a pin
or projection on the switch lever to automatically move the said lever out of contact
with the first mentioned spring contact and into contact with the second one against
which it is held for a suitable period it may be say for about three minutes and then
to release it, whereupon the switch lever is returned to its first position by a spring
and held in this position for a suitable (it may be a like) period, after which the
said operations are repeated. When the apparatus is used in connection with an
electric generator in circuit with electric lamps, the switch lever is provided with an
insulated contact connected with a resistance and arranged in such a manner that
when the switch lever is operated to short circuit the boiler, the circuit of the

page_text: dynamo will be completed through the resistance so that no appreciable effect will
be produced on the lamps.
When the cam is driven by a motor the direction of motion of which is liable to
be reversed, the portion of the switch lever against which it acts can be formed
with inclined surfaces or be otherwise so formed or arranged that the one will be
forced out of contact with the other when the cam rotates in the wrong direction;
thereby preventing damage of the apparatus. Or the cam may be driven through
a ratchet wheel and pawl or through a suitable clutch such as a ball clutch, so that
it can be only rotated in one direction.
Dated this 29th day of March 1892.
W. LLOYD WISE,
Per F. J. Brougham.
COMPLETE SPECIFICATION.
Improved Method of and Apparatus for Lessening or Preventing
Incrustation, Corrosion, and Pitting in Steam Generators and
Apparatus for Imparting Heat to Water, which Invention can be
applied in connection or not with Electric Lighting Apparatus.
We, JAMES BENNETT, Electrician, and JOHN TELLEFSEN, Ship Broker, both
of Merchants Exchange, Cardiff, in the County of Glamorgan, do hereby declare
the nature of this invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:-
This invention has reference to an improved method of and apparatus for lessening
or preventing incrustation corrosion and pitting in steam generators and apparatus
for imparting heat to water, such for example as what are known as feed water
heaters or evaporators.
For this purpose alternately a continuous current of electricity is caused to flow
from an electric generator to an insulated conductor (hereinafter called for
distinction the insulated electrode) and thence to the shell of the steam generator
or other heating apparatus (hereinafter included in the expression boiler) through
the water therein, whereby the said insulated electrode and boiler shall become
charged after the manner of the electrodes in a secondary cell, and then the boiler
and insulated electrode are caused to be short circuited or connected through a
separate conductor, so that a secondary current is caused to flow in an opposite
direction to that first mentioned, from the boiler through the water therein to the
insulated electrode, these operations being repeated alternately and at short
intervals.
'
In conjunction with a suitable source of electricity such as a galvanic battery, or
a dynamo, and one or more plates or electrodes arranged to dip into the water in
the boiler but insulated from the boiler shell, we employ an apparatus comprising a
movable contact arranged to work between two other contacts, and means for
automatically operating the movable contact at short intervals, the arrangement
being such that the said movable contact when in one position, connects for a
suitable time the boiler shell and the insulated electrode to opposite poles of the
electric generator so as to complete the circuit of the electric generator through
the water in the boiler, and in another position breaks this circuit so as to cut out
the electric generator and electrically connect for a suitable time the said boiler
and insulated electrode through a separate conductor.
Such an apparatus can be constructed in various forms.
In the accompanying drawings,
Fig. 1 is a sectional elevation on the line ab Fig. 2; and
Fig. 2 is a plan of one construction of such an apparatus.
Fig. 3 is a diagrammatic view.
In this arrangement the movable contact is in the form of a switch lever 1, 1*
mounted upon, but insulated by a sleeve 1º of insulating material from a pin 2

page_text: carried by a suitable frame or support 3, the lever being held in position laterally.
on the pin by distance pieces 4. The arm 1 of the switch lever, which is of
approximately semi-circular form, is arranged to work between two insulated
contacts or brushes 5 and 6 each carried by but insulated from an adjustable spring
arm 7. One of these spring contacts viz. 5 is when the apparatus is in use, con-
nected by a conductor 8 with one pole of an electric generator 9 and the other (6)
by a conductor 10 with the boiler shell 11. The switch lever 1, 1* is connected by
a conductor 12 with an insulated electrode 13 of suitable material for example iron
suspended within the boiler, all as shown diagrammatically in Fig. 3. 14 is a cam
fixed upon a shaft 15 and rotated through a worm wheel 16, worm 17 shaft 18 and
worm wheel 19, from a worm 20, on a motor shaft 21 that may be the armature
shaft of the dynamo. As will be obvious the cam 14 may be driven in any other
convenient manner. The cam, the convex portion a bc of the periphery of which
is circular, is arranged to act at the required times upon an insulated pin or
projection 22 carried by the arm 1 of the switch lever and to then automatically
move the said lever out of contact with the spring contact and into contact with
the second one 6 against which it is held for a suitable period it may be say for
about 3 minutes, and then to release it, whereupon the switch lever is returned to
its original position by a spring 23 and held in this position for a suitable (it may
be a like) period, after which the said operations are repeated. The time during
which the switch lever will be held in each position depends upon the form of the
periphery of the cam and upon the rate at which the cam is driven. As will be seen
upon reference to Fig. 3, when the switch lever is in the position shewn in full lines,
a current of electricity of a suitable strength and electromotive force will pass from
the positive pole of the electric generator 9 to the insulated electrode 13, thence
through the water in the boiler to the boiler shell 11, and thence by a con-
ductor 10* to the other pole of the electric generator as shown by the arrows in full
lines. During this time oxygen and hydrogen will be liberated respectively on the
insulated electrode 13 and boiler shell which will consequently become charged
after the manner of the electrodes in a secondary battery. When the switch lever
is moved from the position shown in full lines in Fig. 3 to that shown in dotted
lines, the electric generator 9 will be cut out of circuit, and the insulated electrode
will be connected externally with the boiler shell through the conductor 12, switch
lever, spring contact 6 and conductor 10, through which circuit an electric current
of small electro motive force will be caused to flow in the direction of the arrows
shown in dotted lines, in consequence of the charged condition of the boiler shell
and insulated electrode. By thus causing electric currents to flow alternately first
from the electrode through the water in the boiler to the boiler shell and then from
the boiler shell through the water to the electrode, incrustation, corrosion and
pitting of the boiler shell will be considerably lessened or prevented, and owing to
the last mentioned current being of small electromotive force no injury will be
caused to the boiler shell such as has heretofore been usual when alternating
currents have been used for the purpose mentioned. The electro motive force and
strength of the current may vary within considerable limit. Usually a voltage of
about four volts will be found sufficient, whilst the current strength or quantity will
depend upon the size of the boiler. A current strength of about three to four
amperes for a large boiler and about two amperes for a small boiler will be found
to give satisfactory results.
When the apparatus is used in connection with an electric generator in circuit
with electric lamps, the switch lever is provided with an insulated contact, con-
nected with a resistance and arranged in such a manner that when the switch lever
is operated to short-circuit the boiler through the conductor 10 and cut out the
electric generator, the circuit of the dynamo will be completed through the
resistance so that no appreciable effect will be produced on the lamps.
In the arrangement shown, the insulated contact just referred to, is in the form
of a plate 25 carried by but insulated from the switch lever 1-1 and connected
by a conductor 26 with a resistance coil 27 that is connected with the negative pole

page_text: of the electric generator and the resistance of which is equal or approximately so
to that part of the circuit consisting of the contact 6, conductor 10, boiler shell 11,
the water therein, the electrode 13, the conductor 12, and the switch lever. The
contact plate 25 is arranged as shown so as to be out of contact with the spring
contact 5 when the arm 1 of the insulated switch lever bears against such contact,
but to bear against this spring contact and complete the circuit of the electric
generator 9 through the resistance coil 27 just before the switch lever breaks
electric connection with the spring contact 5 and makes electric connection with
the spring contact 6, thereby maintaining the external load on the electric generator
practically constant so that no appreciable effect will be produced on electric
lamps 28 which may conveniently be arranged in parallel with the said apparatus
as shown in Fig. 3.
When the cam 14 is driven by a motor the direction of motion of which is liable
to be reversed, it may be driven through a ratchet wheel and pawl, or through a
suitable clutch such as a ball clutch, in a manner well understood, so that it can be
only rotated in one direction, thereby preventing damage of the apparatus.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that
what we claim is :-
1. The hereinabove described method of lessening or preventing incrustation,
corrosion and pitting in boilers by causing a continuous current of electricity to
flow from an electric generator through the water in the said boiler from an
insulated electrode therein to the boiler shell, and afterwards connecting the said
electrode externally with the boiler shell so that a secondary current is caused to
flow, in an opposite direction to that first mentioned, from the boiler shell through
the water therein to the insulated electrode, these operations being repeated
alternately and at short intervals as set forth.
2. For carrying out the method referred to in the preceding claim, apparatus
comprising a movable contact, two other contacts between which the movable
contact is arranged to work, and means for automatically operating the said movable
contact at short intervals, the arrangement being such that when the apparatus is
in use and the said contacts are connected up with an electric generator and with
the boiler shell and the insulated electrode as set forth, the said movable contact
will in one position connect for a suitable time the boiler shell and the insulated.
electrode to opposite poles of the electric generator so as to complete the circuit of
the electric generator through the water in the boiler, and in another position will
break this circuit so as to cut out the electric generator and electrically connect
for a suitable time the said boiler and insulated electrode through a separate con-
ductor substantially as described for the purposes specified.
3. Providing the movable contact referred to in the preceding claim with an
insulated contact connected with a resistance and arranged in such a manner that
when the apparatus is used in connection with an electric generator in circuit with
electric lamps, and the switch lever is operated to short circuit the boiler through
the separate conductor as set forth, the circuit of the dynamo will be completed
through the resistance so that no appreciable effect will be produced on the lamps,
substantially as described.
4. Apparatus constructed substantially as described with reference to and
shown in Figs. 1 and 2 of the drawings annexed, for the purpose specified, whether
with or without the insulated contact 25 and resistance 27.
Dated this 27th day of Droombo- 1000
W. Lloyd Wise,
Per E. J. Brougham,
J. BENNETT..
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants.