U.S. patent number 3,824,364 [Application Number 05/367,867] was granted by the patent office on 1974-07-16 for apparatus for heating a viscous liquid.
This patent grant is currently assigned to Park-Ohio Industries, Inc.. Invention is credited to John F. Cachat.
United States Patent |
3,824,364 |
Cachat |
July 16, 1974 |
APPARATUS FOR HEATING A VISCOUS LIQUID
Abstract
An open ended tubular heating unit is provided which is
comprised of a stainless steel tube surrounded by an induction
heating coil which is disposed in magnetically coupled relationship
with the tube. The tube and coil are encapsulated in insulating
material, and the unit is submersible in a viscous liquid such as
oil which is disposed in a vessel and the temperature of which
liquid inhibits pumping thereof from the vessel. The unit is
adapted to be supported in suspension and the coil energized to
inductively heat the stainless steel tube, whereby the liquid
inside and surrounding the unit is heated to elevate the
temperature thereof and reduce the viscosity thereof. A driven
impeller may be provided within the tubular unit to impel liquid
flow therethrough, and a driven pump may be provided within the
unit to pump the heated liquid from the vessel.
Inventors: |
Cachat; John F. (Cleveland,
OH) |
Assignee: |
Park-Ohio Industries, Inc.
(Cleveland, OH)
|
Family
ID: |
23448964 |
Appl.
No.: |
05/367,867 |
Filed: |
June 7, 1973 |
Current U.S.
Class: |
219/629; 219/523;
239/135; 166/60; 222/146.5; 392/301; 219/676 |
Current CPC
Class: |
F24H
1/20 (20130101) |
Current International
Class: |
F24H
1/20 (20060101); H05b 005/08 (); H05b 003/00 ();
B67d 005/62 () |
Field of
Search: |
;219/10.49,10.51,523,277,278 ;222/146R,146HS,146HE
;166/57,60,61,302,303 ;239/133,134,135 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Bartis; A.
Attorney, Agent or Firm: Meyer, Tilberry & Body
Claims
Having thus described my invention, I claim:
1. A tubular induction heating device for use in recovering a
viscous liquid from a vessel in which the liquid is at a
temperature which inhibits pumping of the liquid from the vessel
comprising, a single tubular metal member having axially opposed
open ends, induction heating coil means surrounding the exterior of
said member between said opposite ends and disposed in magnetically
coupled spaced relationship therewith, insulating material
enclosing said coil means and tubular metal member and filling the
space between said coil means and tubular member, the portion of
said insulating material within said tubular member defining an
axial passageway through said device, said device being submersible
in said liquid, means to support said device in said liquid from a
location remote from said vessel, and means to connect said coil
means across a source of alternating current at said location for
said coil means when energized to inductively heat said tubular
member to raise the temperature of the liquid.
2. The device according to claim 1, and further including a motor
driven impeller supported by said tubular member within said
passageway and radially spaced from the inner surface of said
passageway to impart movement to said liquid from one end thereof
toward the other, and support means interconnecting said motor
driven impeller and said tubular member.
3. The device according to claim 1, and further including motor
driven pump means supported by said tubular member within said
passageway, said pump means being radially spaced inwardly from the
inner surface of said passageway, and support means interconnecting
said pump means and said tubular member.
4. The device according to claim 3, wherein said pump means has an
inlet for liquid within said passageway and an outlet, and conduit
means connected to said outlet for delivering pumped liquid from
said vessel.
5. The device according to claim 4, and a motor driven impeller
supported within said passageway by said tubular member to impel
liquid flow through said device, said motor driven impeller being
radially spaced inwardly from the inner surface of said
passageway.
6. An induction heating device for use in recovering a viscous
liquid from a vessel in which the liquid is at a temperature which
inhibits pumping of the liquid from the vessel comprising, a single
cylindrical steel tube having axially opposed open upper and lower
ends, an induction heating coil surrounding the exterior of said
tube and disposed in magnetically coupled relationship therewith,
insulating material enclosing said coil and tube and filling the
space between said coil and tube, the portion of said insulating
material within said tube defining an axial passageway through said
device, said device being submersible in said liquid, means for
supporting said device in said liquid from a location remote from
said vessel and in a generally vertical disposition, said support
means including axially open support arm means extending across
said passageway and connected to said steel tube adjacent said
upper end thereof, and means for connecting said coil across a
source of alternating current at said location for said coil when
energized to inductively heat said steel tube to raise the
temperature of liquid within said passageway and promote
circulation of liquid in the direction from said lower end of the
tube toward said upper end.
7. The device according to claim 6, and motor driven impeller means
connected to said support arm means and supported in said
passageway adjacent said upper end of said tube to impel liquid
through said passageway in said direction.
8. The device according to claim 6, and motor driven pump means
connected to said support arm means and supported in said
passageway adjacent said upper end of said tube, said pump means
having a liquid inlet opening and a liquid outlet, and conduit
means connected to said outlet for delivering pumped liquid from
said vessel.
9. The device according to claim 6, including a pump, an impeller
and drive means therefor in said passageway and radially spaced
from the inner surface thereof, said support arm means supporting
said pump, impeller and drive means within said passageway, said
impeller being operable to circulate liquid through said passageway
in said direction, said pump having an inlet port for liquid and an
outlet port, and conduit means connected to said outlet port for
delivering pumped liquid from said vessel.
Description
The present invention relates to the art of induction heating and,
more particularly, to a device for elevating the temperature of a
viscous liquid to facilitate pumping thereof.
Viscous liquids such as oil are often stored in tanks and other
vessels which are exposed to temperature conditions which lower the
temperature of the oil to the extent that free pumping of the oil
is most difficult, if at all possible. For example, a vessel such
as an oil tanker is adapted to store thousands of gallons of oil
for transportation from one location to another across a waterway.
Water and/or air temperature conditions can cause the oil
temperature to drop during the transportation period to a level
which inhibits free pumping of the oil from the vessel when it
reaches its destination. Temperature conditions in cold climates
and during winter months can similarly affect oil contained in
storage tanks and the like. Further, in the event that a vessel
such as an oil tanker sinks before reaching its destination, it
becomes desirable to salvage the oil carried therein. While the air
and/or water temperatures on the surface may not have an
undesirable affect on the viscosity of the oil, the temperature of
the water at the depth of the sunken vessel is likely to be
sufficiently low to adversely effect the viscosity.
To achieve free pumping of the oil under such conditions it is
necessary to elevate the temperature of the oil in order to lower
the viscosity thereof. It has been the practice heretofore to use
steam to raise the temperature of the oil so that it can be freely
pumped. The use of steam together with the necessary devices and
arrangements for transmitting the steam to the vessel entails
considerable expense both in time and cost of equipment. Further,
once the temperature of the oil has been sufficiently elevated to
enable pumping thereof, such pumping must be achieved by apparatus
separate from that employed to generate and direct the steam to the
oil vessel. It will be appreciated, therefore, that the pumping of
oil from a vessel or the salvaging of oil from a sunken vessel in
accordance with prior practices is at best a cumbersome
operation.
In accordance with the present invention, a device is provided
which enables a more expeditious and economical heating of viscous
liquids in a vessel to elevate the temperature thereof to a level
at which the liquid can be readily and freely pumped from the
vessel. The device is of relatively simple and inexpensive
construction and is manipulative into position for use within the
vessel containing the liquid with a minimum amount of effort and in
a minimum amount of time. More particularly, the device is adapted
to be lowered such as by a support cable into the vessel and
submerged in the liquid, and once so disposed the device is ready
for operation.
Basically, the device of the present invention is tubular and
comprised of an inductively heatable metal tube submersible in the
liquid and open at its upper and lower ends to provide for liquid
flow therethrough. In accordance with one aspect of the present
invention, the liquid within and immediately surrounding the tube
is heated to elevate the temperature of the liquid. Convection
current flow causes the heated liquid in the tube to rise and flow
out the upper end thereof and colder liquid to enter the lower end
of the tube.
In accordance with another aspect of the present invention, a motor
driven impeller is disposed within the tube to facilitate
circulation of liquid through the tube from one end thereof to the
other. Such forced circulation of heated liquid from one end of the
tube and cold liquid into the other end of the tube enables the
progressive elevation of the temperature of the liquid in the
vessel and increases the rate at which the liquid is heated during
a given period of time.
In accordance with yet another aspect of the present invention, a
pump is disposed within the tube either alone or together with a
liquid impeller, and the pump has a discharge port connected to a
conduit through which the heated liquid can be pumped from the
vessel.
In accordance with a preferred embodiment, the tube is cylindrical
and is stainless steel. The tube is surrounded by an induction
heating coil which is disposed in magnetically coupled spaced
relationship with respect to the tube. The tube and coil are
encapsulated in insulating material and the resulting tubular unit
is adapted to be suspended in the liquid with its axis extending
generally vertically. A support cable arrangement or the like is
provided at one end of the tubular unit to facilitate raising and
lowering the unit into the vessel. The support cable extends to a
working location remote from the vessel and at which location the
power supply for the coil and other operating equipment for the
unit is disposed. It will be seen, therefore, that the heating
device can readily be elevated and lowered with respect to a liquid
vessel and that nothing more is required to place the device in
readiness for operation beyond locating the device in the liquid
vessel.
An outstanding object of the present invention is the provision of
an induction heating device submersible in a viscous liquid and
operable to elevate the temperature of the liquid to a level which
enhances pumping of the liquid from the vessel.
Another object is the provision of an induction heating device of
the foregoing character which is adapted to be lowered into and
raised from a liquid vessel from a location remote from the vessel
and controlled from the remote location to facilitate the heating
and circulating of liquid in the vessel relative thereto.
A further object is the provision of a device of the foregoing
character which is of tubular construction to facilitate the flow
of liquid therethrough and which is provided with a driven impeller
to impel liquid flow therethrough.
Still another object is the provision of a device of the foregoing
character which is provided with a pump for pumping the heated
liquid from the vessel to the remote location.
Yet another object is the provision of a device of the foregoing
character which enables the heating and removal of viscous liquid
from a vessel in a more expeditious and economical manner than
heretofore possible.
The foregoing objects, and others, will in part be obvious and in
part more fully pointed out hereinafter in conjunction with the
description of the accompanying drawing wherein preferred
embodiments of the invention are depicted, and in which:
FIG. 1 is a sectional elevation view of a heating device made in
accordance with the present invention;
FIG. 2 is a cross-sectional view of a preferred conductor
arrangement for transmitting power to the induction heating coil of
the device, the section being along line 2--2 in FIG. 1;
FIG. 3 is a plan view, in section of the device illustrated in FIG.
1, the section being along line 3--3 in FIG. 1;
FIG. 4 is a sectional elevational view of a modification of the
device illustrated in FIG. 1; and,
FIG. 5 is a sectional elevation view of a further modification of
the device illustrated in FIG. 1.
Referring now in greater detail to the drawings wherein the
showings are for the purpose of illustrating preferred embodiments
of the invention only and not for the purpose of limiting the
invention, a heating device 10 is illustrated in FIGS. 1-3 which is
comprised of a metal tube 12 surrounded by an induction heating
coil 14. Preferably, tube 12 is cylindrical and is a stainless
steel tube having an outer diameter of approximately ten inches and
a wall thickness of approximately 1 inch. Coil 14 is insulated from
tube 12 by suitable refractory insulating material 16 which is
non-flamable and capable of withstanding a temperature of at least
1,000.degree.F. Any suitable refractory insulating material can be
used, one suitable material being glass impregnated mica.
Preferably, both coil 14 and tube 12 are embedded in insulating
material 16 in a manner whereby the inner and outer surfaces of the
heating device and the opposite ends thereof are defined by such
insulating material.
Heating device 10 is adapted to be lowered and raised relative to a
vessel in which viscous liquid to be heated is disposed. Such a
vessel is not illustrated, but it will be appreciated that the
vessel will have or will be provided with an opening of sufficient
size for the heating device to be introduced and removed from the
vessel. Heating device 10 is adapted to be displaced relative to
such a vessel by a support cable arrangement interconnected with
the heating device in any suitable manner. In the embodiment
illustrated in FIG. 1, one end of the device is provided with a
metal support plate 18 including a central portion 20 and legs 22
extending radially therefrom and having outer ends extending
through insulating material 16 and suitably interconnected with
tube 12. Such interconnection can, for example, be defined by
riveting the outer ends of legs 22 to tube 12 and, preferably,
insulating plates 23 are disposed between the legs and tube to
thermally insulate support plate 18 from tube 12. Legs 22 are each
provided with an eyelet component 24 adapted to be interconnected
with a suitable support cable arrangement such as that provided by
cables 26 in the embodiment illustrated in FIG. 1. Cables 26 can be
connected together at a point axially spaced from the end of the
heating device by a single cable 28 extending to the remote
location from which the heating device is raised and lowered
relative to the vessel in which it is to be employed.
Coil 14 preferably is a continuous conductor of solid cross section
having convolutions 15 axially spaced apart along the length of
tube 12. The coil includes end portions 30 and 32 provided with
coupling device 34 and 36, respectively, for connecting the coil
with a suitable source of alternating current, as set forth more
fully hereinafter. Coil ends 30 and 32 extend through corresponding
openings in tube 12, which openings are lined with sleeves 33 of
insulating material.
Support cable 28 extends from heating device 10 to a remote
location and it will be appreciated that the cable can be elevated
and lowered from such location such as by hand, or by a winch or
the like provided at the remote location. The remote location may
be defined, for example, by a platform adjacent a liquid storage
tank, or by a recovery ship in the event that the liquid to be
heated is disposed in a submerged vessel such as an oil tanker.
Further, such remote location might be defined by a dock or the
like at which a vessel such as an oil tanker is docked for
unloading. In any event, it will be appreciated that the heating
device when disposed in the vessel containing the viscous liquid
will be spaced a considerable distance from the remote location
from which the device is manipulated.
The power supply 42 for energizing the coil will also be located at
the remote location and thus will be considerably spaced from the
heating device. Any suitable alternating current power supply may
be provided at the remote location for the purpose of energizing
the coil. In order to reduce line losses in delivering power to
coil 14, the coil and power source preferably are interconnected by
a plurality of flexible conductors connected transversely with
respect to one another. In the embodiment illustrated, end 30 of
coil 14 is connected by coupling device 34 to a pair of conductors
38 and, similarly, end 32 of coil 14 is connected by coupling
device 36 with a pair of flexible conductors 40. The pairs of
conductors 38 and 40 extend from heating device 10 to a common
juncture such as the point at which cable 28 is connected to cables
26. At this point conductors 38 and 40 extend parallel to one
another along cable 28 and are arranged as illustrated in FIG. 2.
More particularly, conductors 38 are of one polarity and conductors
40 are of the opposite polarity. The specific arrangement
illustrated in FIG. 2 provides for reducing line losses in
transmitting current from power source 42 at the remote location to
coil 14. It will be appreciated that pairs of conductors 38 and 40
will be separated at the remote location for connection of
corresponding ones of the pairs of conductors to opposite sides of
power supply 42.
Heating device 10 as thus far described is adapted to be lowered
into a vessel containing viscous liquid such as oil which is at a
temperature below that at which the oil can be readily pumped. The
device is supported in the vessel with its axis in a generally
vertical disposition. Once the heating device is submerged in the
liquid, coil 14 is energized from power supply 42 and the current
flowing through the coil causes steel tube 12 to be inductively
heated. The heat from tube 12 is conducted to the viscous liquid
within and surrounding device 10, whereby the temperature of the
liquid is elevated. As the temperature of the liquid increases, the
liquid will circulate in a well known manner by convection, whereby
the warm liquid will move upwardly through the tubular unit and
colder liquid will enter the lower end of the unit, as indicated by
the arrows in FIG. 1. In this manner, the temperature of the liquid
in the vessel is gradually increased in that the warmer liquid
rises in the vessel and the colder liquid descends therein.
The extent to which the entire volume of liquid in a given vessel
can be heated to elevate the temperature thereof to the desired
level depends, of course, on the size of the vessel, the
surrounding temperature conditions and the extent to which
circulation of the liquid relative to the heating device is
achieved. Accordingly, it may be desirable in certain instances to
provide means within the heating device to positively circulate
liquid therethrough so as to increase the amount of liquid that can
be heated during a given period of time. Such positive circulation
of the liquid is also advantageous in assisting the transfer of
heat from the metal tube to the liquid. Any suitable liquid
circulating arrangement may be provided for this purpose and, in
the embodiment illustrated in FIG. 1, such circulation of the
liquid is achieved by a motor driven impeller disposed within
heating device 10.
As illustrated in FIG. 1, the motor driven impeller unit includes a
rotatable blade 44 mounted on the drive shaft of electric motor 46.
It will be appreciated that motor 46 is potted or otherwise made
fluid tight and impervious to the liquid to be heated. Motor 46 is
supported by support plate 18 and, for this purpose, the housing of
the motor may be suitably interconnected with center portion 20 of
plate 18 such as by a plurality of studs 48 extending through
corresponding apertures in center portion 20 and into threaded
engagement with apertures in the motor housing. Preferably, the
motor housing is insulated from support plate 18 such as by
interposing a plate 50 of insulating material between the motor
housing and support plate. Motor 46 is adapted to be energized
through a conductor 52 extending from the motor to the remote
location for interconnection with a suitable power supply therefor.
Motor 46 may be operated intermittently or continuously to rotate
impeller 44 to impel liquid through the heating device from one end
of tube 16 toward the other. Moreover, the rate at which the liquid
is impelled through the heating device by impeller 44 can be
controlled such as by intermittent operation of the motor or, for
example, by providing for motor 46 to be a variable speed electric
motor. If the heating device is suspended in the liquid so that the
axis of the metal tube 12 is substantially vertical, it is
preferred to provide for the impeller to move the liquid through
the heating device from the lower end thereof toward the upper end
thereof so as to supplement the aforementioned flow of liquid by
convection through the heating device.
When heating device 10 is employed either alone or in conjunction
with a fluid circulating impeller, the liquid in the vessel is
heated to elevate the temperature thereof to a level which provides
for the liquid to be readily pumped from the vessel. Such pumping
can be achieved by a suitable pump unit introduced into the vessel
independently of the heating device. Heating device 10, however,
advantageously provides for pumping to be achieved by a pump unit
physically associated with the heating device, thus to eliminate
the necessity of introducing two separate units into the vessel to
achieve heating and removal of the liquid from the vessel. Such a
heating and pumping arrangement is illustrated in the embodiment of
FIG. 4, wherein a heating unit 10 is depicted which corresponds in
structure to the heating unit illustrated in FIG. 1. Accordingly,
like numberals are used in FIG. 4 to designate components of the
heating device corresponding with the components of the device in
FIG. 1.
In the embodiment illustrated in FIG. 4, a pump 60 is mounted on
support plate 18 in place of the motor driven impeller. Pump 60
includes an impeller 62 disposed within the pump housing and
adapted to be driven by a motor 64 disposed within the housing. Any
suitable pump device may be employed and in the embodiment
illustrated, the pump is a centrifugal pump in which impeller 62
receives fluid centrally thereof and displaces the fluid in a
radial direction. The pump has an inlet opening 66 for fluid within
the heating device and an outlet 68 extending through a suitable
opening therefor in support plate 18. The pump is mounted on
support plate 18 in a manner similar to that described hereinabove
in connection with the motor driven impeller unit in FIG. 1, and it
will be appreciated that the pump motor is fluid tight with respect
to the liquid being pumped. The pump motor is adapted to be
energized through a conductor 70 leading to the remote location for
connection with a suitable power supply, and pump outlet 68 is
interconnected with a flexible conduit 72 which provides for the
delivery of pumped liquid from the vessel to any desired
destination point such as the remote location.
As in the embodiment illustrated in FIG. 1, the energization of
induction heating coil 14 inductively heats steel tube 12 to heat
the viscous liquid in the vessel and cause circulation thereof by
convection through the heating device in the direction of the
arrows in FIG. 4. When pump motor 64 is energized, impeller 62 is
rotated to draw heated liquid within the heating device into the
pump and through outlet 68 to conduit 72 leading to the delivery
location. Accordingly, the embodiment illustrated in FIG. 4
provides a unitary heating and pumping device which enables the
temperature of the viscous liquid to be elevated sufficiently for
the liquid to be freely pumped and for the heated liquid to be
pumped from the vessel. In order to coordinate the pumping rate
with the heating rate of the heating device, motor 64 may be
operated intermittently or may be a variable speed electric
motor.
In the embodiment illustrated in FIG. 4, operation of pump 60 will
to some extent induce liquid flow through the heating device from
the lower end thereof toward the upper end thereof by the suction
created at the pump inlet. This induced flow supplements the
circulation of liquid resulting from flow thereof by convection.
While circulation of the liquid by convection and induced flow may
be adequate, it may be desirable in certain instances to supplement
the liquid flow by a positive circulating device in order to
increase the rate at which the liquid is heated and accordingly the
rate at which it can be pumped from the vessel.
An arrangement suitable for the foregoing purpose is illustrated in
the embodiment of FIG. 5 of the drawing. In FIG. 5, heating device
10 corresponds in structure to the heating devices illustrated in
FIGS. 1 and 4, whereby like numerals are employed in FIG. 5 to
designate corresponding components of the heating device. In the
embodiment illustrated in FIG. 5, heating device 10 is provided
with both a liquid pump and a liquid impeller unit. More
particularly, a motor-pump unit 80 is mounted on support plate 18
in a manner similar to that described hereinabove in connection
with the motor and pump units in FIGS. 1 and 4. Motor-pump assembly
80 includes a pump 82 and a drive motor 84 interconnected as a unit
in a well known manner so that the motor, when energized, operates
the pump. Motor 84 includes a drive shaft 86 extending from the
lower end thereof, and an impeller 88 is mounted on drive shaft 86
for rotation therewith. Pump 82 has an inlet 90 for heated liquid
within the heating device and an outlet 92 to which a flexible
conduit 94 is attached. Conduit 94, of course, leads to a delivery
or destination point for the liquid, such as the remote
location.
Energization of motor 84 causes liquid within the heating device to
be pumped from the vessel to the destination point and causes
liquid to be circulated through the heating device by impeller 88.
While the pump and impeller are illustrated as being driven by a
common motor 84, it will be appreciated that the pump and impeller
can be driven by separate electrical motors. Moreover, the drive
motor or motors may be of variable speed operation to provide for
controlling the liquid pumping and circulating rates. Still
further, it will be appreciated that where a single drive motor is
employed suitable gear box arrangements can be used to provide for
the pump and impeller to be operated at different rotational
speeds.
In the embodiments described hereinabove, the heating device is
suspended by the support cable within the liquid containing vessel
with the axis of the heating device in a generally vertical
disposition. Moreover, the device as illustrated would be suspended
above the bottom wall or the like of the vessel in order to
facilitate circulation of the viscous liquid through the heating
device. It will be appreciated, however, that in these arrangements
the bottom end of the heating device could be provided with
suitable axially extending support leg arrangement which would
enable the device to rest on the bottom surface of a vessel without
hindering free circulation of the liquid into the bottom end of the
heating device. Further, while considerable emphasis has been
placed herein on the fact that the heating device is supported with
its axis in a generally vertical disposition to facilitate natural
circulation of liquid therethrough by convection, it will be
appreciated that in those embodiments in which a pump and/or
impeller is employed that the heating device could be disposed
within the liquid with its axis in a generally horizontal
disposition. In this respect, the pump and/or impeller provide for
circulation of the liquid through the heating device to achieve
progressive heating of the liquid in the vessel. It will be
appreciated too that many suitable arrangements can be provided to
achieve support of the unit in a horizontal disposition, and that
many arrangements other than the specific support plate and cable
arrangement described herein can be devised for supporting the unit
in a vertical disposition.
As many possible embodiments of the present invention may be made
and as many possible changes may be made in the embodiments herein
illustrated and described, it is to be distinctly understood that
the foregoing descriptive matter is to be interpreted merely as
illustrative of the present invention and not as a limitation.
* * * * *