Improvements in Methods of Storing Inflammable Spirits or Highly Volatile Hydrocarbons.
Year: 1891

page_text: Date of Application, 1st June, 1891
Complete Specification Left, 1st Mar., 1892-Accepted, 2nd Apr., 1892
Improvements in Methods of Storing Inflammable Spirits or Highly
Volatile Hydrocarbons.
BENJAMIN HOWARTH THWAITE of 37 Victoria Street Liverpool in the County
of Lancaster, Civil Engineer do hereby declare the nature of this invention to be
as follows:-
-
This invention relates to improvements in methods of storing inflammable spirits,
or highly volatile hydrocarbons, that give off inflammable vapour of a combustible
character.
Briefly described, my invention consists in a method of storing petroleum &
other hydrocarbons, of the more or less dangerous class, whereby such danger
characteristics are eliminated & safety is thus secured.
Around the storage tank that may be of any shape, circular or rectangular, I
provide a water seal of such a depth as will allow the side frames of the cover to
be sealed to a considerable extent.
Even when the oil contents of the tank have been withdrawn, I so arrange the
cover, that there is a continual & close contact of the top plates of cover with the
surface of the oil: prefer to make the upper part of storage tank cover, to serve
as a water tank, in which I constantly supply a layer of water.
For balancing the weight of the cover, 1 provide a counterbalancing arrange-
ment, similar to that used for counterbalancing the moveable part of ordinary gas
holders; but I may avail myself, for counterbalancing purposes, of the arrangement
Known as Pease's wire rope system. In order to withdraw from the holder any
possible accumulation of gas, 1 provide an escape pipe arrangement, the vertical
limb of which works in a vertical & aumular hydraulic seal-this allows for the
lift of cover plates. In ordinary gas works I connect the outlet of this seal to
the gas mains I then connect the upper part of the space (if any) between cover
of oil tank, & surface of oil, with the gas distributing mains, by this means any
accumulation of gas simply diffuses with the ordinary town lighting gas-and,
there is always established under the cover, a pressure of gas that will itself
prevent the admission of air. It will however be seen that there is, under the
cover, a pressure continually established irrespective of the admission of the
town's gas.
For board ship, or tank steamers I may use a sheet iron float cover, having
flexible connections (of india-rubber or canvas) to the store tank sides. This cover,
I so form, that it floats on the surface of the oil, & as the latter is withdrawn, it
falls with the oil, there being sufficient p'ay in the flexible sides to allow this, &
thus as the oil is withdrawn, there is not left behind any possible serious accumu-
lation of combustible gas.
Dated th: 50+1 law of May 1801
B. H THWAITE.
COMPLETE SPECIFICATION.
Improvements in Methods of Storing Inflammable Spirits or Highly
Volatile Hydrocarbons.
BENJAMIN HOWARTH THWAITE 37 Victoria Street, Liverpool, Civil Engineer,
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
5 statement :-
This invention relates to improvements in methods of storing inflammable spirits.

page_text: op
highly volatile hydrocarbons, that give off inflammable vapour of a combustible.
character.
i. J
Briefly described, my invention consists in a method of storing petroleum and
other hydrocarbons, of the more or less dangerous class-whereby such danger
characteristics are eliminated and safety is thus secured.
Around the storage tank, that may be of any shape, circular or rectangular; I
provide a water seal of such a depth as will allow the side frames of a cover to be
scaled, to a considerable extent.
Even when the oil contents of the tank have been withdrawn, I so arrange the
over that there is a continual and close contact of the top plates of the cover,
with the surface of the oil. 1 prefer to make the upper part of storage tank cover,
into a water tank-in which I constantly supply with a layer of water.
For balancing the weight of the cover, I provide a counterbalancing arrangement
similar to that used for counterbalancing the movable part of ordinary gas holder-
but I may avail myself for counterbalancing purposes of the arrangement known as
Pease's wire rope system.
In order to withdraw from the holder any possible accumulation of gas, 1 provide
o escape pipe arrangement, the vertical limb of which works in a vertical and
annular hydraulic seal, this allows for the lift of cover plate.
la ordinary gas works I connect the outlet of this seal to the gas mains, I then
Connect the upper part of the space-if any, between cover of oil tank, and
surface of oil, with the gas distributing mains; by this means any accumulation of
gas simply diffuses with the ordinary town lighting gas--and there is always
stablished under the cover a pressure of gas that will itself prevent the admission
of air.
For board ship or tank steamers I may use a sheet iron float cover, having flexible
connections, of india-rubber or canvas, to the store tank sides, this cover I so form,
that it floats on the surface of the oil, and as the latter is withdrawn, it falls with
the oil, there being sufficient play in the flexible sides to allow this, and thus, as
the oil is withdrawn, there is not left behind any possible serious accumulation of
combustible gas.
Before referring to the illustrations that accompany this. Specification, I wish it
i he understood that, I do not desire to be confined to the use of the exact details
shewn therein, as these may be considerably modified, without departing from the
mainre of the said invention.
Referring to Figures 1 and 2 Sheet 1 of drawings-these represent a section of
my invention in which for balancing the movable cover, I adopt the ordinary
unterbalancing device-with vertical standards.
It will be seen that the general construction conforms to the arrangement usually
adopted for the storage of town lighting gas. The cover A. is preferably formed
to fit the inner side of the tank, and preferably in such a way that it is in close
contact with the oil, a slight pressure equivalent to 2 inches of water, being main-
tained on the surface of the oil.
Around the tank, 1 form an annular space B. which I fill with water, glycerine,
rther suitable liquid medium. Into this water the lower edges of the cover A.
are submerged for some 12 inches at least,-below the water level-effectually pre-
renting the escape of any gas generated from the oil, or the ingress of any air
into the space enclosed over the oil.
The annular space is carried below the main bottom of the tank more than
qual to the depth or extent of the submerged edges of the cover, so that when the
ank is practically empty, the edges of the cover are still, and equally, submerged,
even if the water level in the annular seal was the same level as the bottom of the
iank.
The bottom of the tank C. may be carried by means of radially arranged joists D.
resting on a central casting E.
The gas that may accumulate in the space F' over the oil, can be drawn off by
the annular hydraulic seal arrangement G. This seal arrangement permits the

page_text: holder cover to rise and without disturbing the connection between the space over
the oil F. and the oil gas pipe H.
Oil level gauges J. and water level gauges K. are provided to indicate the
respective level of the fluids.
Any desirable pressure of the cover on the oil can be obtained by increasing the
number of weights.
Instead of the cover conforming to the internal shape of the tank, it may be
simply the ordinary dome form-the space between the oil and the top of cover
being filled with gas, which never escapes.
When advisable, a roof is provided for preventing the rain water from filling the
hollow space due to the shape of the cover.
Figure 3. Sheet 2 of drawings shews a modification of the invention, on which
the system adopted for balancing the cover is the wire rope one-Pease's Patent,
avoiding the employment of standards and ensuring a more uniformly distributed
suspension of the cover.
Figure 4. shews the adaptation of the invention for board ship-instead of the
annular hydraulic space the oil is covered by a floating cover L which is attached
to the internal sides of the vessel M by a flexible or elastic sheet N arranged in
folds so that there is plenty of accommodation for the rise and fall of such
floating cover.
It will be clearly seen that as the oil can be withdrawn without requiring the
introduction of air there can be no possible accumulation of an explosive mixture
nor any other danger.
It is of course understood that I may employ the ordinary dome cover instead of
the form fitting to the internal part of the annular tank.
Having now particularly ascertained and described the nature of my said
invention and in what manner the same may be performed, I declare that what I
claim is included in the following:
1st. The method of storing oil substantially as described.
2nd. The method of storing oil by means of a movable cover with annular or
surrounding hydraulic seal substantially, as shewn and described.
3rd. The method of storing oil on board ship substantially, as described.
Dated this 26th day of February 1892.
B. H. THWAITE.