Water scavenger pouch

A water absorption pouch comprising an open-mesh, hydrocarbon impervious, cloth (e.g., nylon, polypropylene, fiberglass) container confining a water absorbent polymer phase (e.g., mixture of an alkali metal base hydrolyzed starch/acrylonitrile copolymer or alkali metal alkylcarboxamide and a carboxylmethyl or hydroxyethyl cellulose) and sufficient ballast to make the pouch settle to the bottom of a hydrocarbon liquid. Such a water absorption pouch can be tethered and lowered to the bottom of a hydrocarbon containing vessel to absorb a low lying water phase and then removed, dehydrated by squeezing and reused repeatedly.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a highly absorbent pouch useful in removing 
condensed, entrained and/or emulsified water from hydrocarbon fuels or 
oils. More specifically, this invention relates to an open-mesh fabric 
pouch confining a blend of superabsorbent polymers capable of being 
lowered to the bottom of a hydrocarbon container vessel and then absorbing 
many times its weight of water in the presence of the hydrocarbon and 
subsequently being removed, squeezed or compressed to expel water and then 
reused repeatedly. 
2. Description of the Prior Art 
It is generally known that hydrocarbon fuel and oil storage containers, 
particularly containers that are vented to the atmosphere and frequently 
experience liquid level changes, collect water through naturally occurring 
condensation and inherent hydroscopic attraction. Thus, it is not uncommon 
for more than an inch of water to accumulate in the bottom of the 
container. It is also generally known and well accepted that water 
contamination of hydrocarbon liquids frequently represents a serious 
problem. For example, in hydrocarbon fuels (gasoline, diesel, heating oil, 
etc.), water may seriously reduce combustion efficiency, produce noxious 
fumes and smoke and potentially result in catastrophic mechanical failure. 
In lubricating oil and the like, water contamination can be a severe 
detriment to performance by reducing lubrication which in turn can 
accelerate wear to costly bearings and other moving parts. 
Various methods and techniques have been historically employed to 
compensate for or alleviate the problems associated with condensed, 
entrained and/or emulsified water contaminants in hydrocarbon fluids. For 
example, various desiccants and varities of scavenger agents have been 
suggested and employed as well as the addition of costly solvents to 
solubilize the water. Furthermore, it is generally known to provide costly 
auxiliary equipment to hydrocarbon storage facilities and the like to 
facilitate the removal of the water phase. However, the need for an 
inexpensive yet reliable method of reducing condensed and entrained water 
contamination of hydrocarbon liquids wherein the method is generally 
applicable to virtually any hydrocarbon vessel or equipment still exists. 
SUMMARY OF THE INVENTION 
In view of the need for an inexpensive, yet reliable method of removing 
condensed and/or entrained water from hydrocarbon fuel/oil storage 
containers, we have discovered a novel water absorption pouch adapted to 
absorb a free, entrained or condensed water phase settling out of a 
hydrocarbon liquid comprising: 
(a) an open-mesh, hydrocarbon impervious, cloth container confining a water 
absorbent polymer and ballast; 
(b) a water absorbent polymer phase confined within the open-mesh cloth 
container; and 
(c) sufficient ballast confined within the open-mesh cloth container to 
make the pouch settle to the bottom of a hydrocarbon liquid. 
Thus, according to the present invention, the highly water absorbent pouch 
can be tethered such that the pouch can be lowered to the bottom of a 
hydrocarbon containing vessel whereby the low lying water layer can be 
absorbed by the polymer phase which swells to the full volume of the 
fabric container. The pouch can then be retrieved, dehydrated (e.g., 
squeezed) and subsequently reused. In one embodiment of the present 
invention, the highly water absorbent polymer phase is selected from the 
group consisting of an alkali metal base hydrolyzed starch/acrylonitrile 
copolymer and an alkali metal alkylcarboxamide copolymer mixed with a 
carboxymethyl cellulose (CMC) or hydroxyethyl cellulose wrapped in a 
polypropylene mesh and confined to an open-mesh nylon pouch. 
It is an object of the present invention to provide an inexpensive yet 
reliable water absorption pouch which can be lowered to the bottom of a 
hydrocarbon containing vessel and then absorb a condensed or entrained 
water phase settled out of the hydrocarbon or an emulsified, circulating 
water phase. It is an additional object of the present invention to 
provide a pouch that can be withdrawn from the hydrocarbon, dehydrated by 
squeezing or the like and then reused. Fulfillment of these objects and 
the presence and fulfillment of additional objects will be apparent upon 
complete reading of the specification and claims taken in conjunction with 
the attached drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The water absorption pouch according to the present invention, how it is 
made and used, the advantages of its use and how it differs from the prior 
art devices can perhaps be best explained and understood by reference to 
the attached drawing. As illustrated in FIG. 1, the water absorption 
pouch, generally designated by the number 10, is preferably made up of an 
outer fabric layer 12 consisting of an open-mesh cloth. Under the 
open-mesh cloth container 12 is a second optional open weave layer 14 
wrapped around inner water absorbent polymer phase 16 and ballast 18. 
Preferably, the outer layer of the pouch consists of an open-mesh, 
hydrocarbon impervious, cloth or fabric such as a woven synthetic fabric, 
a perforated polymeric film, steel mesh or cotton fabric which allows for 
unrestricted fluid flow. The pouch is sized relative to the confined water 
absorbent polymer phase to allow for expansion and swelling of the polymer 
associated with absorption of water. The choice of cloth or fabric 
includes by way of example, but not limited thereto, open weave polyolefin 
fabric such as polyethylene or polypropylene, nylon mesh, open-mesh 
fiberglass cloth, and the like. Preferably, an open-mesh nylon fabric is 
to be used. The optional second layer of open-mesh fabric can similarly be 
an polyolefin, nylon, fiberglasss or the like cloth with preferably an 
open weave such as a leno weave or net like material being employed. 
Preferably, a polypropylene layer wrapped around the inner polymer phase 
is used as the inner second layer of open-mesh fabric. 
The water absorbent polymer phase confined within the open-mesh, 
hydrocarbon impervious cloth container and optionally wrapped in the inner 
tighter weave fabric is generally any highly water absorbent polymer 
composition that is stable when exposed to conventional hydrocarbon 
fluids. Thus, the present invention contemplates the use of such absorbing 
polymers as hydrolyzed starch copolymers, highly absorbing cellulose such 
as carboxymethyl cellulose or hydroxyethyl cellulose, cross linked 
polyethylene oxide polymers and copolymers, superabsorbent copolymerized 
polysaccharides, cross linked polyacrylamides and the like. Preferably, a 
blend or mixture of at least one highly absorbent polymer such as an 
alkali metal hydrolyzed starch/acrylonitrile copolymer (e.g., potassium 
hydrolyzed starch-acrylonitrile copolymer) or an alkali metal 
alkylcarboxamide copolymer (e.g., potassium propanoate propanamide 
copolymer) and a more fibrous water absorbent polymer such as 
carboxymethyl cellulose or hydroxyethyl cellulose. Experience indicates 
that a blend of potassium hydrolyzed starch-acrylonitrile copolymer and 
carboxymethyl cellulose is capable of absorbing many times it weight in 
water swelling to occupy the full volume of the fabric pouch and then be 
squeezed and reused (in the case of CMC) up to 20 times. 
The ballast employed and confined within the pouch can be essentially any 
high density material sufficient to create an average density for the 
pouch as a whole in excess of the density of the hydrocarbon. Preferably, 
an inexpensive metal or the like is inserted into the polymeric phase 
prior to sealing the pouch. For example, a noncorrosive steel rod can be 
employed or a small segment of copper or lead wire can be placed in the 
pouch prior to heat sealing, gluing or sewing the exterior perimeter of 
the pouch. The optional tether employed according to the present invention 
can be any convenient material such as string, cord, wire, polymeric tape 
or the like. Preferably a string is tied through a hole penetrating the 
outer perimeter of the heat sealed pouch (as illustrated in FIG. 1). 
In order to utilize the water scavenger pouch according to the present 
invention, the device is merely lowered into a hydrocarbon containing 
vessel such that the pouch rests on the bottom in contact with the low 
lying water layer. As illustrated in FIG. 2, the pouch 10 can be lowered 
into barrel 20 by use of string 22 such that the pouch rests in water 
layer 24 of the otherwise hydrocarbon 26 filled barrel 20. Periodically 
the pouch 10 can be retrieved by pulling on tether string 22. The absorbed 
water within pouch 10 can be squeezed out of the pouch and the pouch 10 
then returned to the bottom of the barrel 20. In this manner, the pouch 
can be inserted and removed repeatedly until the water layer is no longer 
present. The vessel can then either be sealed with or without pouch 10 
remaining within the container. 
The following examples are presented to further illustrate specific 
embodiments according to the present invention. 
EXAMPLE I 
A 6 inch square of unidirectional porous nylon fabric was laid out flat and 
a slightly smaller square of coarse open cell polypropylene liner was 
placed on top. Approximately a 3 by 6 by 1/2 inch layer of carboxymethyl 
cellulose absorbent was placed on the open weave polypropylene net and the 
coarse liner fabric was wrapped around the CMC absorbent. A five inch 
piece of lead wire was placed on the porous nylon and the nylon was then 
folded over the lead wire and the polypropylene wrapped CMC absorbent. The 
three outer edges of the nylon fabric was ultrasonically welded, thus 
forming a pouch similar to that disclosed in FIG. 1. A hole was punched in 
one corner of the welded seam and a string was attached to retrieve the 
water absorbent pouch. 
The advantages of using the water presence indicator according to the 
present invention are numerous. The devices provided by the present 
invention represent inexpensive yet universal apparatus for removing low 
lying water deposits and entrained water from virtually any kind of 
hydrocarbon stored in arbitrarily any type of vessel. They allow for the 
direct removal of a low lying water layer in hydrocarbon storage vessels 
containing such fluids as gasoline, diesel fuel, heating fuel and the 
like. Furthermore, the water absorption pouches according to the present 
invention are reusable in that they are capable of absorbing many fold 
their weight of water and then releasing the water when compressed. 
Having thus described and exemplified the preferred embodiments with a 
certain degree of particularity, it is to be understood that the invention 
is not limited to the embodiments set forth herein for purposes of 
exemplification, but is to be limited only by the scope of the attached 
claims, including a full range of equivalence to which each element 
thereof is entitled.