Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This invention relates to the maintenance of idle equipment, such
as internal combustion engines. Such equipment must often be used in en-
vironments which impose temperature levels on the equipment that are extremely
different from the normal operating temperatures of the equipment. For in-
stance, internal combustion engines used outdoors in northern climates
through the winter are often exposed to subzero temperatures. Were the
equipment to be stored at such temperatures, star~ing of the equipment might
be impossible. At best, starting would be difficult and would subject the
movable elements of the equipment to extraordinary wear. It is well known
that lubrication fluids in nonoperational equipment such as engines exper-
ience a decrease in viscosity at lowered temperatures and also tend to drain
from bearings and other lubricated surfaces over extended periods of time
unless the equipment is periodically operated.
To counter these problems, many users of mechanical equipment in
hostile or cold environments must maintain the equipment operational at all
times. Internal combustion engines used outdoors are often operated or idled -
continuously to assure proper heating and lubrication of the equipment be~
tween periods of actual usage. Alternatively, many users of equipment such
as engines, heat and pump coolant liquid through the equipment when it is
not in use. Electrically heated elements and percolating heaters and valve
arrangements for circulating coolant liquids through engine blocks are well
known. However, heating the coolant is not satisfactory in the case of
many heavy-duty engines, because the large aluminum pistons sometimes
present in such engines draw such quantities of heat from the engine block --~ `
that it is almost impossible to maintain a block temperature adequate to
assure subsequent starting.
Another limitation of heaters that circulate coolant liquid through
the block of an engine or through other equipment, is that this usually
has little or no effect on its lubricating system. In an engine, the oil
or lu~ricant normally drains by gravity to a lower pan or sump beneath
the engine elements. Simply heating the engine block has little or no
effect on the cold lubricant in the exposed pan beneath the block. Separate
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pan heaters are needed. Heating the engine block b~ circulating coolant
-fluid and heating lubricant stationary in an engine pan obviously has no
lubricating effect on the engine components themselves while the engine is
not in use.
The present invention was developed in an effort to maintain equip-
ment such as internal combustion engines in operational readiness by cir-
culating coolant or lubricating liquids through the equipment in much the
same fashion as they are circulated when the equipment is operational. By
substantially matching the operational circulation of such liquids, the
machine elements are prelubricated when the liquid being circulated is the
usual lubrication liquid. The lubricating fluid is maintained in a warm
condition and the lubricated surfaces are maintained with a film of lubri-
cant in readiness for subsequent movement. This is achieved while the
normal equipment elements are stationary, and requires only a fraction of
the energy that would otherwise be necessary to operate the equipment at an
idle condition when not in use. Furthermore, this substantially reduces
the wear on the equipment elements, since they can remain stationary while
being warmed and/or lubricated.
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Fig. 1 is a schematic diagram of the present apparatus;
Fig. 2 is an elevation view of the apparatus;
Fig. 3 is a plan view of the apparatus;
Fig. 4 is a right hand end view of the apparatus ;n Pig. 2; and
Fig. 5 is a left hand end view of the apparatus in Fig. 2.
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The invention is disclosed with respect to an internal combustion
engine, which might be a natural gas, diesel OT gasoline powerèd engine of
any conventional type. The engine might be in a stationary location? such
as in a power plant, or might be located in a vehicle? such as an automobile,
truck or railroad locomotive. The type o~ equipment or engine and its
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normal application during usage are irrelevant to an understanding of this
invention. Furthermore, the method and apparatus described herein are
applicable to other types of equipment, as well as to engines. For instance,
they might be used to circulate fluid through systems used in the chemical
industries, such as a scrubber. In such an application, the method and
apparatus might be used to either extract heat from a liquid while the
equipment is idle, or to add heat to the liquid.
As a general statement, the method and apparatus are applicable to ~ -
equipment of the type including a closed liquid recirculation system, hav-
ing a liquid supply and a recirculating pump including a pump outlet and
inlet. The details of the closed liquid recirculation system are not
necessary to an understanding of this invention. In such a closed liquid
recirculation system, various stationary or moving elements in the equip-
ment are normally supplied with a recirculating liquid that is pressurized -~
by operation of a recirculating pump. This pump is operational when the
equipment is operational. It draws the fluid from a liquid supply, pres-
surizes it by pumping, passes the pressurized fluid through the equipment,
and allows the liquid to return to the supply for subsequent use. The -:
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liquid supply can be integral to the equipment or can be separate from it
and connected by appropriate conduits. Various filters and other types of
liquid conditioning devices can be interposed in the recirculation system.
In general, the present method includes the steps of removing liquid
from the liquid supply of the equipment and diverting the removed liquid to ~-
the intake of a supply pump external to the equipment. This step bypasses
the recirculating pump of the equipment, which is not operational when the
equipment itsel-f is not in use. The method involves the further step of `;-conditioning the diverted liquid to a constant temperature by passage
through a heat exchanger. The heat exchanger either adds heat to the liquid
or extracts heat from it, depending upon whether heating or cooling of the
liquid is desired. The diverted liquid, which is pressurized by operation
of the supply pump, is subsequently redirected into the closed liquid re-
circulation system of the equipment under pressure. The conditioned liquid
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is inserted into the recirculation system under such pressure at a location
downstream from the usual outlet of the recirculating pump. While not
essential9 it is generally desirable that the removal of the liquid from
the liquid supply be accomplished at a location in the system close to the
inlet of the recirculating pump thereof, and that the insertion of the con- -ditioned liquid into the system be accornplished at a location close to the
outlet of the recirculating pump.
This method is designed to simulate operation of the equipment so
-far as the liquid recirculation system itself is concerned. The pressure, -temperature and rate of flow of the liquid are such as to assure continuous
liquid circulation through the equipment while the equipment elements are
not in use. In the case of an internal combustion engine, the liquid can
be either a coolant liquid, or more preferably, lubricating oil or fluid.
By heating the lubricant and distributing it through the normal lubrication
system of an engine, one can not only maintain the engine block in a warm
condition despite cold outdoor temperatures, but can also assure the con-
tinued presence of adequate lubrication films on bearing surfaces for start-
ing of the engine without undue wear or difficulty.
The method will be better understoocL by reference to the drawings,
which disclose details of an exemplary apparatus for carrying out the above
steps. The apparatus is schematically illustrated in Fi~. 1. A typical
physical embodiment of the apparatus is shown in Figs. 2 through 5.
Referring to Fig. 1, the equipment with which the apparatus is
used is illustrated as generally comprising an internal combustion engine
schematically shown at 10. The elements of engine 10 comprise part of a
closed liquid recirculation system schematically indicated as being within
dashed line bo~mdaries 11. The recirculation system 11 further includes a
liquid supply or sump 12. In the case of an internal combustion engine,
the liquid supply 12 will be the usual pan beneath the engine, which collects -
the lubricant oil after its passage through the various engine elements.
The system 11 also includes a recirculating pump 13. Again, in the
case of an internal combustion engine, pump 13 is an oil pump powered during
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use of engine 10 and idle when engine 10 is not operational. Pump 13
basically has an inlet 14 in fluid communication with the liquid supply 12,
and an outlet 15, which directs pumped lubricant under pressure to the
various elements of engine 10.
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For purposes of illustration, the schematic diagram also shows a
conduit 16 for returning liquid to the liquid supply 12. The purpose is to
visually illustrate the complete recirculating system. In the case of an
internal combustion engine, the liquid supply 12 is usually a pan beneath
the engine. The engine components are open to the pan and the lubricant
oil drops in to the pan from many different portions of the engine as it
flows downward through the engine block and elements.
In any case, while the equipment is operational, the reciTculating
pump 13 supplies liquid from the liquid supply 12 or sump to the elements of
the equipment in a continuous recirculating fashion. Various filters or
other conditioning devices (not shown) can be interposed within the system in
the usual fashion.
Referring again to Fig. 1, the present apparatus is shown to the
Ieft of the recirculation system 11 for equi-pment 10. It comprises a con-
clitioning tank 18 or heat exchanger within which liquid can be either heated
or cooled. It also comprises a supply pump 22 which is external to the
equipment and independently powered by a motor 36. Pump 22 includes an in-
let 23 operatively connected to the liquid supply 12 and an outlet 24
operatively connected to the conditioning tank or heat exchanger 18. The
conditioning tank 18 has an outlet operatively connected to the liquid
recirculation system 11 by means of a discharge conduit 31. When in use,
pump 22 removes liquid from supply 12, diverts it through the conditioning
tank 18, and directs the conditioned liquid under pressure back into the
recirculation system 11. The pressurized liquid then continues through
equipment 10 in the same fashion as when it is circulated durin~ operation
of equipment 10. The liquid stream can be used for heating, cooling and/or
lubrication of equipment 10 so as to maintain it in readiness for subsequent :
use in any environment.
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The details of the apparatus are shown more clearly in Figs. 2
through 5. As illustrated, the apparatus can be mounted upon a supporting
frame or pallet 17. This frame 17 can be portable or stationary, depending
upon the manner in which the equipment is being used. As an example, the
frame 17 might be maintained outdoors in a stationary position for attach-
ment to portable vehicles, such as trucks or railroad locomotives. Alter-
natively, the frame or pallet 17 might be portable and readily moved or
carried to the location of the equipment with which it is to be utilized.
The conditioning tank 18 is shown as an elongated cylindrical tank
having an inlet at one end and an outlet at the other for continuous flow
of liquid through the length of the tank. Tank 18 is illustrated as con-
taining a coaxial elongated heating element 20. This might be an electrical
resistance heating element operated by a heater control 21 mounted to one
end of the tank 18. However, it is to be understood that the tank 18
might have many other physical configurations, and might be heated or
cooled by means external to it, as well as by an internal element as shown.
Pump 22 is a conventional rotary pump. Pump 22 includes an inlet 23
and an outlet 24. Other types of suitable circulation pumps can be sub-
stituted. Motor 36 is shr~n as an electric motor, but can be a small
intcrnal combustion engine if the unit is used where electric power is not
readily available.
Inlet conduit 25 operatively connects the inlet 23 of pump 22 to the
liquid supply 12 of the equipment recirculation system 11. Since this
apparatus is used only when the equipment 10 is nonoperational, it is
desirable that it be readily disconnected from the equipment. This is
particularly needed in the case of equipment of a portable nature, such as
a truck engine. This can be accomplished by a releasable coupler 27 of
the type conventionally used for disconnecting hoses to mechanical equip-
ment. A check valve 26 is preferably interposed within inlet conduit 25.
Check valve 26 permits flow of liquid toward inlet 33 but prevents reverse
flow. In normal installations, check valve 26 will remain as part of the
recirculation system 11, automatically assuring that normal operation of
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equipment 10 will have no effect on the auxilliary equipment that maintains
it in readiness for use.
An outlet conduit 28 extends from pump outlet 2~ to the inlet of
the condi-tioning tank 18. Interposed in the conduit 28 is a thermostatic
element 30 that monitors the temperature of the liquid flowing through
conduit 28.
A final discharge conduit 31 extends from the outlet of condition-
ing tank 18 to the recirculation system 11. It is directed to a point in
the system reasonably close to the outlet of the equipment's recirculating
pump 13. A flow control valve 32 and associated flow control switch 33 is
interposed within conduit 31 adjacent to the outlet of the conditioning
tank 18. A coupler 35 releasably connects the outlet of tank 18 to the
pressure side of pump 13.
The various components of the apparatus can be electrically con-
trolled to provide automatic monitoring of its operation and thermostatic
control of the temperature of the liquid being circulated through the system
11. Suitable electric controls are schematically illustrated at 38. The
controls 38 are electrically connected to motor 36, heating element 20,
thermostatic element 30, and flow control switch 33. -
Under normal use, the thermostatic element 30 is preset to the
temperature at which the liquid is desired. Until the circulating liquid
reaches this temperature, the thermostatic element 30 will continue opera-
; tion of heating element 20 to add heat to the liquid system. When the
; desired temperature has been reached, heating element 20 will be turned
off until the liquid temperature again falls below this predetermined
temperature leve.
I To insuTe against damage to the heating element due to lack of
liquid recirculation, the flow control switch 33 monitors the passage of
liquid through the conditioning tank 18. So long as flow continues, the
switch 33 remains inactive. It is activated by lack of flow through dis-
charge conduit 31. This activation is used to immediately open the cir- ;~
cuit to the heating element 20 to prevent damage to it and to prevent -
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damage to the liquid within conditioning tank 18, which might be very
sensitive to heat. Should flow be only momentarily interrupted, the
switch 33 will be deactivated and the circuit to heating element 20 will
again be completed through operation of the controls at 38. However, the
controls 38 should include a time delay circuit to monitor activation of
the flow control switch 33. If flow has ceased for a predetermined time,
the controls 38 will then shut down the entire apparatus and require manual
restarting of it. In this way, operation of the apparatus can be automa-
tically monitored, while assuring that there will be no damage to the
fluid being circulated~ nor to the equipment 10.
The purpose of the apparatus is to provide circulation of the
liquid, such as lubricant oil, through the equipment 10 while the equip-
ment 10 is not operational. The pump 22 is preset to direct liquid to
the system 11 at a pressure similar to the normal operating pressure
encountered within it during its use. The ~lermostatic control 30 is
set in conjunction with the element 20 within conditioning tan~ 18 to
either heat or cool the liquid to a temperature similar to its normal
operating temperature. The flow control valve 32 is preselected or adjusted
to assure that the rate of flow of the liquid through the system 11 will
simulate normal operating conditions. Thus, lubricating oils, coolants
or other liquids can be continuously circulated through the nonoperational
equipment to effect heat transfer to the equipment elements while the
equipment is not in use. If the liquid is a lubricating fluid, surface
lubrication is also effected, maintaining the movable elements of the
equipment in readiness for starting and subsequent use without the normal
wear encountered between movable surfaces that have remained stationary
for substantial periods o:E time and which require proper lubrication.
Various modifications might be made with respect to the details
of the equipment, while remaining within the boundaries of the apparatus
and method discussed above. For these reasons, the following claims are
set out as definitions of the disclosed invention.
