U.S. patent number 3,844,507 [Application Number 05/342,545] was granted by the patent office on 1974-10-29 for process for the transportation of impellent gases, for example natural gas, and apparatus for carrying out the process.
Invention is credited to Hermann Ernst Robert Papst.
United States Patent |
3,844,507 |
Papst |
October 29, 1974 |
PROCESS FOR THE TRANSPORTATION OF IMPELLENT GASES, FOR EXAMPLE
NATURAL GAS, AND APPARATUS FOR CARRYING OUT THE PROCESS
Abstract
A method and a device for transportation of natural gas and
other buoyant impellent gases, without the need for expensive pipes
and liquid tank cars or ships are described. The natural gas is
air-lifted from a starting point to a consignment point by means of
voluminous, light, hollow bodies, and said bodies being borne en
route to the consignment point by the lift of the impellent gases.
Upon release of the gas at the consignment point, the bodies are
filled with another buoyant gas for the return trip to the starting
point. At the starting point the said buoyant gas is again
exchanged for impellent gas which is to be transported, so that in
both directions substantial additional quantities of supplementary
freight goods can be transported.
Inventors: |
Papst; Hermann Ernst Robert
(Schwarzwald, DT) |
Family
ID: |
27182134 |
Appl.
No.: |
05/342,545 |
Filed: |
March 19, 1973 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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69328 |
Sep 3, 1970 |
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Foreign Application Priority Data
Current U.S.
Class: |
244/30 |
Current CPC
Class: |
B64B
1/62 (20130101) |
Current International
Class: |
B64B
1/00 (20060101); B64B 1/62 (20060101); B64b
001/02 () |
Field of
Search: |
;244/30,31,96,97,98,128,126,12S,61 ;114/16E,74R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Reger; Duane A.
Assistant Examiner: Barefoot; Galen L.
Attorney, Agent or Firm: Cushman, Darby & Cushman
Parent Case Text
This is a continuation, of application Ser. No. 69,328 filed Sept.
3, 1970, now abandoned.
Claims
What is claimed is:
1. A process for the transportation of impellent gases being
lighter than air, e.g., natural gas or hydrogen, from a starting
point at which the impellent gas is available to a point of
consignment, characterized by the steps of:
substantially completely filling a large capacity, light,
inflatable hollow body with impellent gas at the starting
point,
transporting the impellent gas by air with said hollow body to a
point of consignment, said hollow body being borne through the air
solely by the buoyancy of the impellent gas contained therein,
compeltely discharging the impellent gas at the consignment point,
while maintaining said hollow body inflated by supplying said
hollow body with heated air as said impellent gas is discharged, so
that said hollow body will be borne through the air on its return
journey to said starting point solely by the buoyancy of said
heated air, maintaining said heated air at an elevated temperature
during the return journey, and
discharging said heated air after returning to said starting point
so that said hollow body can be filled with more impellent gas at
said starting point as heated air is discharged.
2. The process according to claim 1 characterized in the combined
measure that the difference in buoyancy power between the hollow
body being filled with the impellent gas on the delivery journey
and the hollow body being filled with the buoyant gas for the
return journey is balanced by adequately different amounts of
ballast.
3. A process for the transportation of impellent gases being
lighter than air, e.g., natural gas or hydrogen, from a starting
point at which the impellent gas is available, to a point of
consignment, characterized by the steps of:
substantially completely filling a large capacity, light,
inflatable hollow body with impellent gas at the starting
point,
transporting the impellent gas by air with said hollow body to a
point of consignment, said hollow body being borne through the air
solely by the buoyancy of the impellent gas contained therein,
completely discharging the impellent gas at the consignment point,
while maintaining said hollow body inflated by supplying said
hollow body with a mixture of water vapour and heated air as said
impellent gas is discharged, so that said hollow body will be borne
through the air on its return journey to said starting point solely
by the buoyancy of said mixture of water vapour and heated air,
and
discharging said mixture of water vapour and heated air after
returning to said starting point so that said hollow body can be
filled with more impellent gas at said starting point as said
mixture of water vapour and heated air is discharged.
4. A process for the transportation of impellent gases being
lighter than air, e.g., natural gas or hydrogen, from a starting
point at which the impellent gas is available, to a point of
consignment, characterized by the steps of:
substantially completely filling a large capacity, light,
inflatable hollow body with impellent gas at the starting
point,
transporting the impellent gas by air with said hollow body to a
point of consignment, said hollow body being borne through the air
solely by the buoyancy of the impellent gas contained therein,
completely discharging the impellent gas at the consignment point,
while maintaining said hollow body inflated by supplying said
hollow body with water vapour as said impellent gas is discharged,
so that said hollow body will be borne through the air on its
return journey to said starting point solely by the buoyancy of
said water vapor,
maintaining said water vapour at an elevated temperature at about
100.degree.C. when transporting the hollow body on said return
journey to said starting point, and
discharging said water vapour after returning to said starting
point so that said hollow body can be filled with more impellent
gas at said starting point as said water vapour is discharged.
5. The process according to claim 4, characterized in that the
water vapour is held during the return trip at a temperature that
corresponds to its dew point by means of heat exchanges which
receive exhaust heat from drive engines associated with the
propulsion system of the hollow body.
Description
BACKGROUND AND BRIEF DESCRIPTION OF INVENTION
The invention relates to a process and a transport device for the
transportation of impellent gasses, for example natural gas or
hydrogen, from a starting point at which the impellent gas is
available to a place of consignment at which the impellent gas is
to be used.
In making natural gas available for use, there is the substantial
difficulty that transportation of the gas from a point at which it
is obtained to industrial plants where it is to be used entails, in
general, very high investments in terms of pipe lines and pumping
stations, which, moreover, are often utilizable for only a few
years because many sources of natural gas are relatively rapidly
exhausted.
It is known, of course, that natural gas can be liquefied and can
be transported by means of deep cooling tanks to the points of
consignment or to the central pipe line connections in harbors.
Aside from the fcct that for this kind of transportation
considerable amounts of pipe lines overland to the harbors and from
the harbors are required, the liquefying of the gas and the
transportation of the liquefied gas involves high expenditure and
is potentially dangerous.
For this reason it is not worthwhile to exploit average or smaller
sources of natural gas at a distance from the places of
consignment, and thus, natural gas is wasted in the course of
petroleum recovery and is uselessly burnt up, although with its
large fraction of gaseous alkanes it is of considerable value not
only as a fuel but also, for example, for the production of
synthetic materials.
The object of the invention therefore is the development of a
process and a system for the transportation of impellent gases,
particularly natural gas and pure methane gas, or even helium,
which avoids the drawbacks of known arrangements, whereby gas of
this type can be delivered to points of industrial use from remote
locations in an economical and safe way.
The invention involves a process for transporting an impellent gas
in voluminous light hollow bodies which are particularly insulated
for a slight loss of heat. These bodies are moved through the air;
and en route to a point of consignment they are supported by the
buoyancy of the impellent gas and can carry along balancing freight
or ballast. Upon release of the impellent gas at the place of
consignment they are filled with another cheap buoyant gas and
freight or ballast which is available everywhere for the return
journey to the starting point, where buoyant gas is again exchanged
at the starting point for more impellent gas to be transported.
An especially advantageous example of the invention consists in
providing the transporting hollow bodies with self-propelling and
heat insulated hulls which are, in the return journey to the source
of the impellent gas, kept filled with heated gases, for example
air and/or steam. For this return transportation of the hollow
bodies to the source of impellent gas, hot or heated air will be
the cheapest and the simplest material to use, if the airship is
built light enough for this. A preferred embodiment comprises the
use of saturated steam and a saturated steam-air mixture as buoyant
gas for the return trip. The steam is held in the return journey at
a temperature which corresponds to its dew point in that as much
fresh steam is delivered as is condensed by the heat loss of the
carrying body.
Steam is relatively cheap and is available in industrial centers as
a side product that is difficult to utilize (for instance, in
steam-electric generator plants). When the body is re-filled at the
starting point, the steam can be either condensed and utilized as
water or simply let out. For balancing the heat loss by the
non-rigid hull, the heat of the exhaust gases of drive engines can
be used.
On the journey, steam, corresponding to the partial pressure
relationship of the steam-gas mixture, which corresponds to the
condensation or dew point, may be used supplementarily to the
impellent gas as a buoyant gas. It is especially advantageous
because of its high heat of evaporation for stabilizing the
temperature of the buoyant gas. Walls of the non-rigid envelope of
the airship can be double walled and can be partitioned off by
bulkheads to from gas-tight sections. In order to prevent danger of
fire from the natural gas charge in the hollow body, the
intermediate space between the double walls of the non-rigid hull
is held at excess pressure of air or a non-combustible gas, for
example nitrogen, carbon dioxide or sulfur hexafluoride (SF.sub.6).
Lines for the pressurized gas in the intermediate spaces lead to
the separate sections.
Complete security against fire even in an experiment with
combustion can be developed in that the combustible impellent gas
for the trip can be mixed with a fraction of steam, whereby the
combustibility of the impellent gas-steam mixture is reduced or
eliminated. For this it can be sufficient to add to the impellent
gas, for example methane, about 27 percent steam; and by the low
partial pressure of the steam a temperature of 67.degree. C will be
maintained. For recovery of the pure natural gas, the steam
addition will be condensed at the point of consignment. With this
method it is also possible to transport relatively heavy gases,
such as ethane, propane, butane, etc., with the necessary lift
being developed by a correspondingly high amount of steam or
another buoyant gas in separated chambers within the hollow
envelope.
On the other hand, in special cases during transportation, it is
possible to use a specific amount of steam, held constantly at the
dew point and separated from the impellent gas, for heating the
buoyant gas for greater support. Since there is practically no
difference in pressure between a chamber filled with natural gas
and another chamber filled with steam, suitable separating
partitions can be made which are therein and correspondingly light.
These partitions can also be double walled.
In order however to meet the problem of heat loss in the
transportation of gases in the special conditions of using hot air
and steam, an airship of the type described in U.S. Pat. No.
3,456,903 is recommended. Accordingly, the invention consists also
in the use of an airship of this kind as transporting body. Such an
airship is an engine driven, semi-rigid dirigible with an inflated
double walled, non-rigid envelope for containing a volume of
buoyant gas. The double walls of the envelope are filled with a
gas, for instance air or CO.sub.2, which is a poor heat conductor,
under a pressure that is higher than the maximum pressure of the
buoyant gas. Between the inner and the outer wall there are
intermediate members that prevent heat convection as much as
possible. In addition, there are flat elements extending between
the walls, whereby steam as a buoyant gas and heat transfer medium
acts within the double walled non-rigid envelope as saturated
steam. The intermediate members comprise closely disposed,
collapsible traction connections that connect the inner and outer
wall practically radially, and the flat elements comprise closely
disposed supplementary, collapsible heat reflecting surfaces, which
are disposed in a zig-zag between the inner and the outer wall.
A transporting hollow body of this kind allows the carrying out of
the process of the invention surprisingly well. With more or less
complete expulsion or sucking out of the heat insulating gas from
the intermediate space in the double wall, particularly in the
upper region of the non-rigid envelope (and also with its
invertible intermediate partitions) a pronouncedly increased heat
transfer can be effected, in that the walls of the double wall can
contact each other, when needed, to thereby pronouncedly accelerate
condensation of the steam which is enveloped by the hull. This
reduction of the protective gas pressure in the double wall
envelope is attained, for example, by means of the lift pressure of
the gases enveloped by the hull. The heat insulating gas which is
expelled by said gas pressure can be taken up in expanding
containers outside or inside the non-rigid envelope.
The special propulsion of this hollow body is primarily suited to
the use intended in the present invention. This consists of air jet
propulsion means that are provided with compressors driven by low
noise level engines disposed on a keel structure of the
transporting hollow body. The propulsion means is in the form of a
jet nozzle that has an annular gap nozzle aperture about an inset.
This arrangement provides for a steering device in that the inset
body and the annular gap of the nozzle opening are adjustable by
control devices disposed axially and radially with reference to the
long axis of the nozzle.
For take-off and landing on terrain that is not specially prepared,
the use of a special landing means is also proposed. The airship
has a rigid keel structure with a substantially flat rigid bottom,
which is furnished on its underside with a hose-like cushion seal
that encloses the bottom surface. At least one suction opening of a
suction fan is provided in the enclosed bottom. On landing, the
airship immediately sucks air from under the keel when the cushion
seal approaches the ground surface and is applied to it, so that
the intake pressure is transmitted to the ground. This keel frame
can also be made floatable so that at sea it can serve as a ship
hull. If with this landing means the suction side of the strong
propulsion compressors are used for sucking the airship, there is
an optimally safe landing and the airship is most reliably anchored
even at wind velocities up to the maximum of e.g., 144 km/hour.
In special adaptation of the airship used according to the
invention for the transportation of gases, the airship is converted
in a particularly advantageous embodiment so that it presents
symmetrically disposed and flexible partitions inside the buoying
body, which partitions are invertible and divide the inner chamber
of the buoying body into separate compartments and the present
separate gas intakes and outlets. Thus the capacity of the separate
compartments can be controlled, to range practically from zero to
the complete capacity of the buoying body by means of the
invertible partitions, with filling of one compartment and emptying
of the other and vice versa.
To maintain a uniform altitude in flight, or uniform weight of the
hollow body, the engines may be driven advantageously about half
with propellant fuel and half with impellent gas (methane), so that
the buoyancy by the consumption of the propellant fuel is reduced.
In operation of the engines with fuel oil alone, the reduction in
buoyancy through condensation of steam will advantageously be
initiated only toward the end of the flight, so that flight can be
at a greater height and hence on the average somewhat faster.
As a special advantage of the method of gas transportation by air
through a hollow or a container it is to be noted that both on the
way out and on the return substantial amounts of supplementary
freight can be carried, e.g., sand, crude oil, and other products
(heavy machinery, drill rigs), and also, because of the explosion
proof gas charge, passengers. Such transport-hollow bodies can take
off and land in the most out of the way places and they are
independent to a considerable extent of storm conditions, all the
more so since the heat insulating non-rigid envelope of this
invention reduces the effect or outside temperature on the gas that
is being carried.
With the method of the invention not only will there be elimination
of the pipelines and liquid gas tankers that have been used so far,
but the transportation of impellent gases can also be effected
without the loss of time that is entailed in such arrangements. A
gas transporting hollow body of this kind can have, for example, a
diameter of 106 m and a length of 364 m.
The useful load of natural gas (with 90 percent transport gas
filling minus gas for own use) is about 1,900,000 cubic meters of
CH.sub.4 (100.degree. C) and the additional free freight capacity
is 1,200 t, e.g., for oil. On this basis the transport cost comes
to 0.222 German pfennings for each cubic meter natural gas and
1,000 km distance if at the same time 1,200 t oil with the same
computation of caloric value is transported.
The invention is described below in more detail with reference to
various examples as illustrated.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows a filled hollow body or container with a preferred
arrangement of inner partitions (dashed lines) within its hollow
envelope;
FIG. 2 shows the hollow body of FIG. 1 when its envelope has been
emptied;
FIG. 3 shows the same hollow body in a re-filled condition;
FIG. 4 shows a longitudinal view of the stern of an airship like
hollow body;
FIG. 5 shows a schematic cross section through the keel structure
with a hose-like cushion seal on the underside;
FIG. 5a shows an enlarged cross section taken from the heat
insulating double walled non-rigid envelope of the hollow body as
indicated in circle Va of FIG. 5; and
FIG. 6 shows a schematic representation of an airship with various
gases in symmetrically filled compartments that are constituted by
the invertible partitions.
DETAILED DESCRIPTION OF INVENTION
The hollow body or container for the gas transport having a shape
like an airship 4 as shown in FIGS. 1 through 3 comprises a
transport body having a hollow bow section 1, a hollow, cylindrical
mid-portion 2, and a hollow stern part 3. The hollow body is formed
as an envelope 40 made up of a double walled construction of the
type shown in greater detail in FIG. 5a. The double walled
construction includes an inner wall 41 and an outer wall lamination
42, 43, and 44. The inner and outer walls are radially
interconnected by traction devices 45 that are spaced about 5 cm
apart. Air, or another non-combustible gas, e.g., nitrogen or
carbondioxide, as introduced between the inner and outer walls of
the envelope at a pressure above the inflation pressure of the
buoyant gas contained within the main space within the envelope.
This assures a stability of the hollow body 40 during flight, and
in addition, provides for a gas-filled intermediate space 13
between the two walls making up the envelope. This space functions
as a protective shield around the gas contained in the envelope and
as a heat insulating layer around the envelope. In addition to the
heat insulating characteristics of the intermediate space 13, the
two wall surfaces are provided with thin metallic layers, e.g., 42
that does not limit the flexibility of the envelope and which are
both compact and sealed against diffusion. Also, inside the
intermediate spaces 13 between the walls, there are metal coated
thin foil surfaces fixed at their extremities to the outer and
inner walls and which present a plurality of folded reflecting
surfaces, e.g., in a zig-zag configuration. Heat radiation is thus
reflected so that the heat insulation is improved. These foil
surfaces are not interconnected lengthwise, so that a balance of
pressure inside the intermediate spaces 13 is not prevented. Heat
convection flows are prevented by the close spacing of the
individual foil strips and the intermediate strips. The buoyant
space inside envelope 40 can be defined with reference to the bow 1
and the stern 3 by flexible walls that are similar to invertible
heat insulating walls 7 of the envelope mid-section 2.
The inner sections 3a and 4a of envelope 40 are separated by walls
7 with reference to the stern 3 and the bow 1, respectively, and
are in direct connection with the outside air (or they may be
connected via auxiliary blowers and possibly via a propulsion
compressor) to create a uniform pressure differential. Since walls
7 have an extent that is much greater than the inner cross section
of envelope 40, they can, depending upon the difference in pressure
between the buoyant gas and the atmosphere, either puff out into
the bow or stern part of the envelope (see the double dashed
position A of FIG. 1) or they can reverse into the propellant gas
chamber (see the plain dashed position of FIG. 2). In this way the
conically shaped bow and stern sections of envelope 40 can also
function as trim and stabilizing cells.
Thin foldable walls 33 are sealed to the places of attachment of
walls 7 inside envelope 40. Walls 33 with walls 7 form two separate
chambers which can be filled or emptied via connections 15 and 17.
As soon as a gas has been admitted via connection 16 and the
contents of the chamber enclosed by walls 33 has been drawn out or
forced out via connections 15 and 17, walls 33 according to FIGS. 1
and 3 are pressed against walls 7 of the envelope so that
practically the entire space inside the envelope can be filled via
connection 16.
The hollow body 1-3 according to FIG. 4 is propelled by nozzles 9
on the stern 3 (see FIG. 4). From these nozzles air is driven out,
as delivered via passages 5 from engine-driven compressors in keel
structure 10. The drive of the compressors can be effected by
diesel engines or by natural gas engines. The control of hollow
body 1-3 is effected by the radial and axial displacement of nozzle
body 22, with reference to the longitudinal direction of the said
hollow body, by means of adjusting members 8 (by known hydraulic
devices), so that an annular gap 9 of the nozzle can be suitabley
varied. This control effects an adequate maneuverability for the
hollow body.
A keel structure 10 is fixed under envelope 40 by belts 31 (see
FIG. 5) for providing space for crew and passengers, and space for
all freight and whatever machines are accommodated. The keel
structure can be made seaworthy so that the airship can come down
on the water at sea.
According to FIG. 5 the keel structure 10 is built as a pipe
construction 23 whose inner chamber can safely accept liquid fuel.
The keel frame has a hose-shaped cushion, or semi-circular sealing
protuberance, 24 around at least a part of its bottom surface, with
which elements it is set down on the landing surface. Within these
sealed bottom surfaces there opens the suction side of a compressor
6' so that the keel frame is sucked firmly against the ground in
starting and landing. Instead of a special compressor 6' a
compressor 6 of the propulsion means can effect the suction
directly to obtain immediate holding.
In the keel structure 10 there are also devices e.g., steam boilers
or heat exchangers for creation of steam. The heat of the exhaust
gas of the propulsion engines is also utilized for this purpose.
Excess is carried off with the nozzle air. On keel structure 10
there are also connections for conduits 15, 16 and 17 at suitable
locations for the filling and emptying of the individual
compartments for the buoyant gas.
The natural gas that is to be transported can be shipped, as shown
in FIG. 1, in the closed mid-section container 14 which is filled
and emptied via connections 16. The mid-section chamber of
container 14 can be formed directly between the invertible walls 7
and inner walls of envelope 40 or additional thin invertible walls
33.
As shown in FIG. 1, the additional thin separating wall 33 can be
adjacent to the wall 7 which can be turned inside out on the side
lying toward the cylindrical center part 2, to thereby define
between the walls 33 an inner space for the container 14. Adcording
to FIG. 3, on the other hand, there can be in each end one more
wall 33 provided. Thus, separate chambers can be formed by walls
33, and the separate chambers can be filled according to choice
with different gases, such as natural gas and/or hydrogen and/or
helium. The filling and emptying of the various chambers by mutual
displacement and expansion of the individual chamber contents has
been shown schematically in FIG. 6, wherein natural gas is shown at
27.
On both ends container 14 is surrounded by steam 29 or hot air 28
so that if there is a leak of natural gas from container 14 it will
only be mixed with the steam. For the transportation process
container 14 is filled full with natural gas, at the expense of the
surrounding steam-filled space, whereby the steam is either drawn
off via connections 15 and 17 or is condensed by cooling, for which
the heat insulating intermediate chamber in walls 7 is compressed
by removal of its excess pressure by cutting off an idling
auxiliary compressor.
If at the place of consignment the natural gas is to be discharged,
steam 29 or hot air 28 is let into the buoyant chamber through
connections 15 and 17 and at the same time a corresponding amount
of the impellent gas, i.e., natural gas or hydrogen or helium, is
drawn off via connection 16.
The chambers for the buoyant gas can be alternatively sub-divided
by substantially horizontal partitions into compartments for the
gases that are to be kept separate, and the compartments can be
provided with separate connections.
The gas transport hollow bodies can be made without difficulty in
diameters of more than 100 m.
In practical operation it can be advantageous to take off by means
of the greatest possible gas load with an excess in buoyancy in
order to reach great heights rapidly and to expend less propulsion
energy. In use of a part of the transported gas in the compressor
engines the buoyancy slowly decreases so that at the place of
consignment an exact balance is arrived at. For the continuous
supply to industry and other gas consumers at the place of
consignment there will advantageously be a permanent to-and-fro
traffic with a number of gas transport airships.
The cost of transportation with airships drops by about the square
of the speed for given distances. It is therefore advisable to
provide an optimal estimated speed of about 150 km/hour and to use
large ships. With increasing size of the airship the required
buoyancy increases only in relationship to the cross section area,
while the contents increase cubically, so that a large airship is
advantageous. Non-rigid airships have no specific limit for their
size because the weight of the envelope increases only linearly
with the contents at given velocities.
In addition to the advantages that have been mentioned it should
also be noted that the method of the invention offers the most
economical of possibilities for geographically flexible gas
transportation so that the customary waste of natural sources could
be stopped thereby.
* * * * *