U.S. patent application number 10/041898 was filed with the patent office on 2003-02-20 for purified water supply system for high demand devices and applications.
This patent application is currently assigned to Gambro, Inc.. Invention is credited to Bielefeld, John D., Hannah, Johnny W., Luehmann, Douglas A., Mullins, Stephen M..
Application Number | 20030034305 10/041898 |
Document ID | / |
Family ID | 26718670 |
Filed Date | 2003-02-20 |
United States Patent
Application |
20030034305 |
Kind Code |
A1 |
Luehmann, Douglas A. ; et
al. |
February 20, 2003 |
Purified water supply system for high demand devices and
applications
Abstract
A water supply sub-system for connection to a main water supply
system, in which the sub-system includes: a storage tank having an
inlet for connection to the main water supply system, an outlet and
an outlet line connecting the outlet of the storage tank to a pump
which pumps water from the tank to a sub-system supply line. One or
more branch connections are connected to the sub-system supply
line. Connectable to the one or more branch connections are one or
more high-demand water using devices, such as dialyzer re-use
machines. The subsystem may feed water to these high demand
devices, and the sub-system and the one or more high demand devices
may thus be substantially isolated from the main water supply
system so that the high demands thereof will not adversely impact
the water supply parameters. Thus, one or more lower demand
machines, such as dialysis machines, may be connected to the main
line without supply parameter disruption thereto. The sub-system
preferably further includes a feedback loop and the storage tank
preferably has a spray head disposed therein, the spray head being
disposed to spray inlet and/or recirculated feed back water into
said storage tank. Among other alternative options, an
ultrafiltration device may also be included in the sub-system
supply line to ensure the purity of the water circulating through
the sub-system.
Inventors: |
Luehmann, Douglas A.;
(Battle Lake, MN) ; Hannah, Johnny W.;
(Timberville, VA) ; Mullins, Stephen M.;
(Lakewood, CO) ; Bielefeld, John D.; (Prairie
Village, KS) |
Correspondence
Address: |
GAMBRO, INC
PATENT DEPARTMENT
10810 W COLLINS AVE
LAKEWOOD
CO
80215
US
|
Assignee: |
Gambro, Inc.
|
Family ID: |
26718670 |
Appl. No.: |
10/041898 |
Filed: |
January 7, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60260036 |
Jan 5, 2001 |
|
|
|
Current U.S.
Class: |
210/646 ; 137/1;
210/257.2; 210/258 |
Current CPC
Class: |
B01D 61/025 20130101;
A61M 2205/84 20130101; A61M 1/1656 20130101; C02F 1/44 20130101;
C02F 1/444 20130101; Y10T 137/0402 20150401; B01D 61/08 20130101;
Y10T 137/0396 20150401; B01D 61/02 20130101; B01D 61/10 20130101;
Y10T 137/0318 20150401; Y10T 137/86035 20150401; C02F 1/441
20130101; A61M 1/1668 20140204; B01D 61/145 20130101; B01D 61/58
20130101; Y10T 137/85954 20150401 |
Class at
Publication: |
210/646 ; 137/1;
210/257.2; 210/258 |
International
Class: |
B01D 061/26 |
Claims
Accordingly, what is claimed is:
1. A water supply sub-system for connection to a main water supply
system, said sub-system comprising: a storage tank having an inlet
for connection to said main water supply system, and an outlet; an
outlet line connected to the outlet of said storage tank; a pump
connected to said outlet line; a sub-system supply line connected
to said pump; and a branch connection connected to said sub-system
supply line.
2. A sub-system according to claim 1 wherein a high-demand water
using device is connectable to said branch connection to receive
water from said water supply sub-system.
3. A sub-system according to claim 2 wherein said high-demand water
using device is a dialyzer re-use machine.
4. A sub-system according to claim 2 wherein said high-demand water
using device is a dialyzer pre-cleaning machine.
5. A sub-system according to claim 1 wherein said sub-system
comprises a plurality of branch connections whereby a plurality of
water using devices may be simultaneously connected to respective
branch connections so that said plurality of water using devices
may simultaneously receive water from said water supply system.
6. A sub-system according to claim 1 further comprising a feedback
loop connected to said sub-system supply line.
7. A sub-system according to claim 6 wherein said feedback loop is
disposed downstream of said branch connection.
8. A sub-system according to claim 6 wherein said feedback loop is
disposed upstream of said branch connection.
9. A sub-system according to claim 6 in which said storage tank has
a spray head disposed therein, said spray head being connected to
said inlet to said tank and being disposed to spray inlet water
into said storage tank, said spray head also being connected to
said feedback loop to receive recirculated water therefrom and
spray said recirculated water into said storage tank.
10. A sub-system according to claim 1 in which said storage tank
has a spray head disposed therein, said spray head being connected
to said inlet to said tank and being disposed to spray inlet water
into said storage tank.
11. A sub-system according to claim 1 further comprising an
ultrafiltration device disposed in said supply line downstream of
said pump and upstream of said branch connection.
12. A sub-system according to claim 1 whereby said sub-system is
used in a medical application.
13. A sub-system according to claim 1 whereby said sub-system is
used in a pharmaceutical manufacturing application.
14. A sub-system according to claim 1 whereby said sub-system is
used in an electronics manufacturing application.
15. A water supply system comprising a water processing unit; a
main inlet line connected to said water processing unit; a main
outlet line leading from said water processing unit; a plurality of
main branch connections emanating from said main outlet line; and a
water supply sub-system connected to said main water supply system,
said sub-system comprising: a storage tank having an inlet and an
outlet, said inlet being connectable to one of said plurality of
main branch connections; an outlet line connected to the outlet of
said storage tank; a pump connected to said outlet line; a
sub-system supply line connected to said pump; and a sub-system
branch connection connected to said sub-system supply line.
16. A water supply system according to claim 15 wherein the water
processing unit is a water purification device.
17. A water supply system according to claim 15 wherein the water
processing unit is a water storage device.
18. A water supply system according to claim 15 wherein a low
demand water device is connected to one of said plurality of main
branch connections emanating from said main outlet line.
19. A water supply system according to claim 18 wherein said low de
mand water device is a dialysis machine.
20. A sub-system according to claim 15 wherein a high-demand water
using device is connectable to said branch connection to receive
water from said water supply sub-system.
21. A sub-system according to claim 20 wherein said high-demand
water using device is a dialyzer re-use machine.
22. A sub-system according to claim 20 wherein said high-demand
water using device is a dialyzer pre-cleaning machine.
23. A sub-system according to claim 15 whereby said sub-system is
used in a medical application.
24. A sub-system according to claim 15 whereby said sub-system is
used in a pharmaceutical manufacturing application.
25. A sub-system according to claim 15 whereby said sub-system is
used in an electronics manufacturing application.
26. A method for providing water from a main water supply system to
a high demand device without adversely impacting the water flow
parameters of the water flowing in said main water supply system,
said method comprising, connecting a supply sub-system to said main
supply system, said sub-system comprising: a storage tank having an
inlet for connection to said main water supply system, and an
outlet; an outlet line connected to the outlet of said storage
tank; a pump connected to said outlet line; and connecting a high
demand device to said supply sub-system; flowing water through said
main water supply system and into said sub-system; flowing water in
said sub-system to said high demand device for its use.
27. A method for providing water according to claim 26 wherein said
main water supply system has a low demand device connected thereto
and wherein said step of flowing water through said main water
supply system includes flowing water to said low demand device.
28. A method for providing water according to claim 27 wherein said
low demand device is a dialysis machine.
29. A method for providing water according to claim 26 wherein said
high demand device is a dialyzer re-use machine.
30. A method for providing water according to claim 26 wherein said
high-demand water using device is a dialyzer pre-cleaning
machine.
31. A method for providing water according to claim 26 which
further comprises a step for disinfecting the main supply system
using heat whereby the sub-system is isolated from main supply
system during the disinfecting step.
32. A method for providing water according to claim 26 which
further comprises a step for disinfecting the sub-system using a
chemical whereby the sub-system is isolated from main supply system
during the disinfecting step.
Description
INTRODUCTION
[0001] The present invention relates generally to water supply
systems, and more particularly to a system adapted for supplying
purified water to one or more water using devices, some of which
having distinctive water consumption demands, including devices
having distinctively and usually intermittently high demands versus
devices having low demands for flow rates and/or volumes of
purified water. This invention further presents particular
advantages in medical and like high quality purified water supply
systems such as in allowing for the supply of water to both high
demand dialyzer reprocessing machines and lower demand dialysis
machines without substantially increasing the total operational
volume or flow rate of purified water flowing through the entire
water supply system.
BACKGROUND
[0002] There are presently a variety of industrial and medical
devices and associated procedures that require the use of purified
water. A prominent example is found in medical dialysis. In such
dialysis procedures generally, including hemodialysis,
hemofiltration and hemodiafiltration processes, blood to be
dialyzed is taken from a patient and passed through a dialyzer
where the blood is cleaned of its impurities and then returned to
the patient. Contemporary dialyzers are ordinarily of a membrane
type in which the blood may be passed along one side of the
membrane, while in the most common types of dialysis, another
liquid, often called dialysate, may be passed along the opposite
side of the membrane. This process is conceptually the same in
plate, hollow fiber and coil dialyzers. Ideally, impurities in the
blood pass from the blood through the membrane and into the liquid
dialysate. The liquid dialysate carrying these impurities then
flows out of the dialyzer and is usually passed through a dialysis
control monitor or machine to a drain. Some types of dialysis also
include providing a replacement liquid to the patient, the
replacement liquid being passable with the blood through the
dialyzer, or otherwise often being infused directly into the blood
returning to the patient.
[0003] The dialysate and replacement liquids are both generally
made from purified water into which various additive solutions
and/or powders are mixed to create respective liquid solutions that
are usually substantially isotonic to blood. Often this mixing of
additives with purified water may be effected at and/or by each
discrete dialysis machine (also known as a monitor) during each
dialysis session. This process is often referred to as on-line
dialysate or replacement liquid preparation. A centralized,
substantially continuous supply of purified water may then
preferably be presented to one or more of such on-line dialysis
machines in a particular setting such as a hospital or a dialysis
clinic for the preparation of these respective liquids during
operation.
[0004] In a centralized water supply system such as this, it is
common to provide a centralized purification arrangement including
a reverse osmosis (R/O) apparatus or unit and/or a deionization
(DI) apparatus or unit among other purification devices, such as
carbon and/or mechanical filters and/or chemical treatment devices
such as water softeners. There may also be additional water
treatment for the removal of bacteria and/or endotoxins or the
addition of or subjection to electromagnetic waves, e.g.,
ultraviolet light for the inactivation or destruction of such
pathogens. In any event, the R/O or DI unit commonly establishes
the last purification step in the purification arrangement which,
as is known in the art, then provides output purified water to
medically acceptable and/or otherwise preferable or desirable
quality or like standards.
[0005] As mentioned above, this purified water may then be
delivered in a typical dialysis setting to one or a plurality of
dialysis machines, preferably through short branch connections
emanating from a main or central supply line. The central supply
line may then provide for the flow any unused water to a drain or
it may form a circuit by feeding back into one or more of the
purification devices (such as the R/O unit) for re-purification
and/or to other units (such as a central storage tank) and
then/thereby provide for recirculation out to and through the
central supply line circuit.
[0006] Other machines that use purified water have also been known
to be commonly connected to such a centralized water supply line.
An example particularly fitting within a hospital or dialysis
clinic setting is the connection to the purified water circuit of
one or more dialyzer re-use machines (also known as dialyzer
reprocessing machines). As is understood, dialyzer re-use machines
use the purified water to clean dialyzers after respective dialysis
sessions for re-use in later dialysis procedures.
[0007] One common concern arising from such an incorporation of
dialyzer re-use machines is the relatively high water demand such
re-use machines usually require to complete their cleaning
procedures. Re-use machines normally require a high volume (though
usually intermittent) flow rate of water, albeit usually for a
short time period when compared with the lower (usually more
constant) demand, longer term dialysis machine use. However,
contemporary centralized purified water circuits often have
relatively constant maximum output flow rates, depending ordinarily
upon the maximum output of the respective R/O unit if, as is
common, the R/O unit feeds directly into the main water supply
circuit. The high demands of one or more re-use machines connected
to a main supply line can then significantly negatively impact a
centralized water supply system having an R/O unit which directly
feeds water at a constant maximum output. The negative impact of
the high demand is such that it may overburden the main water
supply system by drawing too much water flow from the main supply
line to the point that the flow of purified water provided
simultaneously to any other water using machines such as one or
more dialysis machines may be reduced, interrupted or the central
line pressure may be decreased sufficiently so that one or more of
the dialysis machines do not have sufficient water volume or
pressure to continue producing dialysate and/or replacement fluid,
as needed for the dialysis procedure, and may thus be forced into
an alarm state and possible automatic shut-down. Such alarms and
possible shut-downs may then provide a danger to the dialysis
patient(s).
[0008] Note, R/O and/or DI feeding into intervening holding tanks
is known in the art. However, such tanks have been disposed in the
primary water circuit, and as such are often necessarily
unacceptably too large (approximately 250 gallons) for many
medical/dialysis settings and/or have too many stagnation areas (as
in bladder surge tanks) thus providing unacceptable opportunities
for undesirable biological and/or microbiological growth.
Additionally, these prior holding tank systems must maintain high
flow rates throughout their piping systems to maintain turbulent
flow which minimizes bacterial growth. There are usually large
pressure drops through such piping systems due to the high flow
rates and long lengths of the piping system as well as due to the
number of taps for each water using unit to be attached to the
piping system. Intermittent high demand devices such as dialyzer
re-use equipment draw large amounts of water out of the piping
system in a short period of time. This may cause the pressure
levels to drop sharply throughout the piping system, thereby likely
causing both the reuse equipment and any other attached water-using
equipment, such as dialysis machines, to not have sufficient water
volume and/or pressure to operate properly.
[0009] Other industrial water usage machines and water supply
circuits may also suffer similar drawbacks. Such systems may
include pharmaceutical preparation processes and/or electronic
device (e.g., microchip) manufacturing processes. Thus, any system
which may include the use of both low and high water demand devices
on a water supply line may take advantage of the present
invention.
[0010] Hence, a need exists for providing for a safe,
non-overburdensome connection of high water demand devices, like
dialyzer re-use machines, to a water supply line so that other
lower demand machines, such as dialysis machines, may be provided
with a sufficient, uninterrupted supply of water volume, pressure
and/or flow rates to maintain normal operations. It is toward this
and related aims that the present invention is directed.
BRIEF SUMMARY OF THE INVENTION
[0011] The present invention is directed to the provision of a
water supply sub-system which is connectable to a centralized or
main water supply system. The sub-system provides for the
connection of one or more relatively high demand water using
devices in a substantially isolated or lower demand disposition
relative to the main water circuit. Generally, the present
sub-system includes a sub-system storage tank which is connectable
to the main water supply system, and a sub-system water line to
which the high demand device or devices may be attached. This
sub-system water line (also referred to in some recirculatable
embodiments as a loop, see below) is connected to and leads from
the sub-system storage tank, through a pump to one or more outlet
connections for a potential variety of generally high volume flow
rate demand, short duration water use devices such as dialyzer
re-use machines. This further sub-system water line may be dead
ended (thus, no loop), or run to a drain or drain connection, or
more preferably, it may feed back to the sub-system storage tank
for recirculation therethrough (and, thus form a loop). A shunt
line may additionally or alternatively be connected to the
sub-system water line to provide pressure control for the output
from the pump, and/or for more directly feeding from the pump back
to the storage tank for the same or perhaps a similar general
recirculation purpose. At least one of these recirculation lines
preferably feeds into or near the top of the storage tank and feeds
through a spray head arrangement therein (thus completing the loop)
which disperses the incoming water in a substantially continual
spray configuration to maintain a substantially constant movement,
non-stagnating air to water interface within the tank. This assists
in maintaining a preferably more sterile environment within the
storage tank. The other feedback line may preferably feed into a
lower part of the storage tank to counteract vortex action at the
tank outlet. A microbiological filter and/or various other
components may also be included in or along the sub-system water
line to ensure and/or increase operational effectiveness and/or
efficiency.
[0012] In use, purified water may be taken into the sub-system
storage tank from the centralized supply system at a substantially
controlled, relatively constant low rate so that a substantially no
or low fluctuation demand is presented by the sub-system to the
central or main supply system. The tank can then feed a short
duration, higher volume flow rate to the rest of the sub-system,
which, including one or more high water demand devices, can then
draw the respective higher flow, higher volume demands from the
outflow of the sub-system storage tank while the storage tank
continues to draw the preferably constant, substantially lower
maximum volume flow rate from the main supply system. This high
demand draw may have the effect of drawing down the total volume
contained within the sub-system storage tank, but does so generally
for only a comparatively short duration and preferably not to an
empty state. The maximum intermittent high demands of the high
demand devices may thus be accounted for within the total operating
storage tank volume. The high demand devices may then be operated
at any time during which the storage tank contains a sufficient
residual water volume without then impacting on or interrupting the
main supply of water to the lower demand, longer duration dialysis
or like machines connected directly to the main line.
[0013] As noted, systems of the present invention may be highly
beneficial in purified water supply systems such as in medical
applications like dialysis, or may also be useful in pharmaceutical
preparation or electronics manufacturing or other water supply
processes.
[0014] These and other aspects of the current invention will become
clearer from the description of preferred embodiments considered in
conjunction with the attached drawings which are described briefly
below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Accordingly, in the drawings,
[0016] FIG. 1 is a schematic view of a centralized purified water
supply system in which the present invention may be
incorporated;
[0017] FIG. 1A is a schematic view of an alternative centralized
purified water supply system in which the present invention may be
incorporated;
[0018] FIG. 2 is a schematic view of a water supply sub-system
according to the present invention as connected to the centralized
purified water supply system of FIG. 1;
[0019] FIG. 3 is an enlarged schematic view of a preferred
alternative sub-system according to the present invention, shown
detached from a central water supply system; and
[0020] FIG. 4 is a schematic view of a sub-system like that in FIG.
3 showing a further alternative line connection.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] A centralized or main water supply system 10 is shown in
FIGS. 1 and 1A including a water treatment or purifying unit 12
which feeds purified water either directly into an outlet purified
water supply line 14 (FIG. 1) or indirectly to line 14 via an
intervening storage tank 13 (FIG. 1A). Unit 12 is preferably here a
reverse osmosis (R/O) or de-ionization (DI) unit 12, and either of
these or other types of treatment units may be considered here even
if R/O is used in the description here. Water line 14 is the
distribution line which may also be referred to as the main line 14
herein to distinguish it from various other water lines to be
described throughout this specification. An inlet feed line 15
which feeds into treatment unit 12 will be understood as feeding
water from any of various sources or combinations of sources (none
shown) such as from a tap and/or from one or more pre-treatment or
filtration devices (carbon and/or mechanical filter(s) and/or
chemical or water softening or like water treatment device(s), for
example, none shown). Moreover, feed line 15 may also alternatively
receive feedback water from the purified water line 14 via a
connecting line 17 (shown in dashed lines in FIGS. 1 and 1A) to
create a main supply circuit or loop 16. An alternative feedback
line 17a (FIG. 1A) provides for feedback of water to the storage
tank 13, if used.
[0022] The water system main line 14 is shown having a plurality of
connection branches generally designated in FIG. 1 with the
reference numeral 18. One or more water using machines 20 may then
be connected through respective branches 18 to the central or main
water line 14. In this description particularly of FIG. 1, machines
20 may be considered relatively generically such that they may be
understood to represent, for example, one or more dialysis
machines, and/or for another example, one or more dialyzer re-use
machines, inter alia. As was described hereinabove, it has been
known in the art to connect one or more dialysis machines and/or
one or more dialyzer re-use machines to a single main water supply
line 14. Further devices, machines or outlet taps have been known
to be similarly connected to a main line 14 in a dialysis setting
as well, including, for example, taps for centralized bicarbonate
concentrate preparation, dialyzer pre-rinse or dialyzer cleansing
devices (e.g., for cleaning a dialyzer prior to use of the dialyzer
in a dialysis process, also referred to as pre-cleaning devices,
herein), and/or pre-rinse sensor or sink cleansing devices. Any
such devices are intended also to be represented interchangeably by
the generic reference numeral 20 in FIG. 1. Water used thereby may
then be flowed to a drain via a respective drain line 21. This
water may alternatively be returned to the inlet of the treatment
unit 12, see line 17 in FIG. 1, or to a central storage tank 13,
see FIG. 1A.
[0023] Nevertheless, because of the pressure fluctuations in main
line 14 caused by high demand devices, in the present invention,
the direct connection of generic water use machines 20 as shown in
FIG. 1 to the main line 14 is preferably restricted, as shown more
particularly in FIG. 2, to the connection of low water or
substantially constant water demand machines 20A (FIG. 2). Thus,
the generic water machines 20 of FIG. 1 which are directly
connected to main line 14, are hereafter referred to in the present
invention as low demand machines 20A (FIG. 2). Low demand machines
20A include, for example, dialysis machines. Higher demand machines
20B (see FIG. 2), such as dialyzer re-use machines will, according
to the present invention, be connected to and/or within a water
supply sub-system which is identified schematically in FIG. 1 by
the box designated 25, and is shown in more detail in FIG. 2 within
a dashed box outline similarly identified by the reference numeral
25 therein.
[0024] More particularly in FIG. 2, a sub-system inlet line 26 is
shown schematically connecting the water supply sub-system 25 to
the main line 14 through its connection at one end of line 26 to a
main system outlet branch 18 of the main line 14, and at the other
end to a sub-system storage tank 28. Emanating from tank 28 is a
storage tank outlet line 30 which flows to a pump 32. Pump 32 is
preferably of a centrifugal type which may thus be pressure
controlled at the outlet thereof as will be described below. At the
outlet of pump 32 is an outlet line 31 which is connected to or is
coincident with a sub-system supply line 33 which provides water to
one or more branch connections 34, to which may be connected one or
more respective water using machines, such as the representative
high-demand machine 20B shown in FIG. 2. Note, tank outlet line 30,
pump outlet line 31 and supply line 33 may be separate elements, or
they may all be contiguous or coincident with each other (depending
upon the pump type used), or in either event, they may be simply
considered to comprise a single outlet supply line for simplicity
of description.
[0025] Also shown in FIG. 2 are three alternative additional flow
paths (shown in dashed lines), at least two of which providing
preferred alternatives to the dead-ended supply line 33 indicated
in FIG. 2 by the dead-end 35 (dead-ended refers to the
non-recirculating flow stopping effect the dead-end 35 provides at
the end of supply line 33). The first alternative is a drain line
36 which provides a drainage flow path for unused water to flow to
a drain (not shown). The second alternative flow path which is
presently preferred over or at least in addition to a drain line
36, is a feed-back loop 38 which provides for flowing any unused
water back to the storage tank 28 for recirculation as described in
more detail relative to FIG. 3 below. The third alternative flow
path is provided by a feed back shunt line 40 which is disposed
upstream of the branch connections 34 to provide for the
alternative of providing pressure regulation and recirculating
unused water to the storage tank 28 simultaneously with (or perhaps
without) flowing the unused water through the entire loop 38.
Preferably, all three alternatives to the dead-end 35 will be
provided in subsystem 25. However, any one or more of these
alternative flow paths (or none of them, as depicted in FIG. 2) may
be disposed in a sub-system 25 according to the present invention
and could be simultaneously so connected and may be connected by
shutoff or three-way valves or the like (not specifically shown).
Any one or more of these flow paths may thus be chosen for
directing water flow therethrough at any given time as may be
desired. Further examples of such flow choices and the preferred
purposes therefor will be described below.
[0026] A further detailed embodiment of a preferred sub-system 25
according to the present invention is shown in FIG. 3. Many of the
alternative elements included herein are preferred within the scope
of the present invention, but may be added to, substituted for or
eliminated as may be appreciated by those skilled in the art. Inlet
line 26 preferably also includes a connecting device 42 and one or
more valves, preferably a check valve 44 and a flow control valve
46. The connecting device 42 is preferably a male connector which
may or may not include a shutoff which would mate with a female
connector 43 which preferably includes a shutoff (not shown)
disposed in or attached to the branch 18 or directly emanating from
the main line 14 (thus constituting the branch 18, shown
schematically in FIG. 1). The check valve 44 maintains flow in one
direction from main line 14 to the tank 28 and is preferably
disposed adjacent or near the connecting device 42. The flow
control valve 46 may be more preferably disposed adjacent the inlet
48 to the storage tank 28. The flow control valve 46 provides for
flow rate control into tank 28, and in the preferred embodiment is
not variable or operator manipulable. Rather, valve 46 is
preferably a manufacturing chosen size based on the maximum burden
to be presented by the one or more high demand machines (see 20B)
considered in combination with the lowest acceptable main water
line supply minimum flow rate with which sub-system 25 may be used.
This may thus take into account the quantity and type of lower
demand machines (dialysis and the like, e.g.) which may be designed
to be connected to the main line 14. Different sized valves 46
could thus be used depending upon the quantities and/or types of
lower demand devices 20A might be used, as well as what the
operating output of the particular purification unit 12 being used.
Valve 46 may also, in a less preferred alternative embodiment, be
used to provide manual on/off control of flow into tank 28.
[0027] Inside the storage tank 28 (shown in cross-section in FIG.
3), an extension 49 of the inlet line 26 preferably runs from
and/or through a float valve 50 to provide inlet flow into tank 28.
Water flowing into tank 28 through inlet line 26 would preferably
flow through valve 50 and the extension 49 to fill the tank 28. As
the tank fills with inlet water to a pre-determined level, the
water will move the float arm assemblage 51 upwardly and thereby
cause closure of float valve 50 and halt further water inflow into
tank 28 through line 26.
[0028] Storage tank 28 also preferably has a vent 54, an access
port 55 and a disinfectant inlet port 56. Vent 54 is preferably a
0.2 micron porous membrane filter vent to allow air flow
therethrough, but not ingress of biological contaminants such as
bacteria. Substantially atmospheric operating pressures may thus be
achieved within tank 28, though without risk of contamination.
Access port 55 allows operator access for manufacturing,
maintenance, parts replacement or cleaning as desired, and port 56
provides for flowing disinfectant solution therethrough into tank
28 for disinfection procedures carried out on a preferably regular
basis (see description below).
[0029] One or more recirculation inlets 58, 68 are preferably also
provided in storage tank 28 for connection, as described below, of
one or more recirculation loops. The first such feedback loop 38 is
connected to tank 28 via a first inlet line 41 through inlet 58. An
inlet extension line 59 extends through inlet 58 to provide for
communication of recirculation flow into tank 28. As shown,
extension line 59 is also preferably connected to the sprayhead
arrangement 52 for spraying recirculated water into tank 28. The
spraying action of the sprayhead 52 creates a preferably
continuously moving air to water interface within the tank 28 to
thereby inhibit the initiation or growth of biological organisms
(including microorganisms) or other contamination. This is in
contradistinction to a known bladder surge tank (not shown) having
a bladder therein which resiliently expands with in flowing water
and returns when a water using device draws water therefrom. Dead
air spaces abound therein and provide for the proliferation of
contaminants and/or microorganisms. In a speculative embodiment,
inlet line 49 from main supply connection line 26 may also be
connected to a sprayhead (not shown) such as sprayhead 52 and/or
potentially even be connected to the same sprayhead 52; but more
likely each would be separately coupled to distinct sprayheads (not
shown).
[0030] A pressure valve 60 is preferably disposed in the shunt
feedback line 40, the pressure valve being situated to control the
pressure in the outlet flow lines from pump 32. A pressure
sensor/control assembly 61, including a sensor gauge 63 is
preferably disposed on valve 60 to sense the pressure in line 40,
as well as in the output line 31 and the initial portion of line 33
up to filter 70 (if used, see below). A line extension member 62
extends from the valve 60 through an opening 68 into storage tank
28 for flowing water from loop 40 into the interior of tank 28
through valve 60. The pressure in line 40 controls the activation
(restriction) of valve 60, or more appropriately, the control
assembly 61 may be used to set the pressure to be established in
line 40 and the pump outlet line 31, 33, which pressure is effected
by the valve 60, controlling the pressure out of pump 32. The
pressure gauge 63 may also be used for operator monitoring of the
interior pressures in lines 31, 33 and 40 and a relief valve 64 may
also preferably be supplied to relieve excess pressures. An
optional, but preferred downspout 65 is shown in dashed lines in
FIG. 3 demonstrating the option of feeding water into tank 28 for
dispersal at or near the bottom thereof to counteract vortex
creation as will be described further below.
[0031] In the respective tank outlet and sub-system circulation
lines 30 and 33, a few additional preferred elements are also shown
in FIG. 3. Two valves 67 and 69 are shown one each on opposite
sides of the pump 32 and may be used to provide for controlling the
flows out of the tank 28 and into the circuit sub-system 25. A
stopcock 45 is also preferably disposed in line 30 to allow for
draining water on the inlet side of pump 32, for maintenance, inter
alia.
[0032] A filtration device 70 is also shown in sub-system supply
line 33 and is preferably used here to ensure that the water
flowing through the sub-system 25 remains free of contaminants. Two
pressure sensors 72, 74, one on each side of the filter 70, are
used for monitoring and thus also assisting in maintaining proper
control of the trans-membrane pressure thereof. Adjacent stopcocks
76, 78 may be used both during priming and/or for taking test
samples as may be desired or necessary (see below). Filtration
device 70 may be of several types preferably restricting the
transmission of microorganisms and as is preferable herein, it may
be an ultrafiltration device, preferably dead-ended as understood
in the art, with no cross-flow established through the dead-ended
inlet 80A and outlet 80B, respectively.
[0033] In a general description of use, the sub-system 25 of any of
FIGS. 1-3 receives water from the main water supply system 10
(FIGS. 1 and 2) through inlet line 26 from main system line 14.
This water then fills tank 28 to a preferred level, as described
above, with water then also proceeding out through the tank outlet
line 30 (if and when valve 67 is opened; FIG. 3). This outlet water
is then preferably pumped by pump 32 into and through the
sub-system supply line 33. And, when connected to one or more
high-demand machines 20B, preferably through a respective valve 39
(FIG. 3) at a branch 34, then during operation of these high-demand
machines 20B, they draw the water they need from line 33 through
the respective one or more branch connections 34 and corresponding
valve(s) 39. If sub-system supply line 33 is not dead-ended (as
shown with a preferred feedback loop 38 and the optional drain line
36 in FIG. 3), then the unused water flowing through sub-system
supply line 33 flows to and through the chosen alternative line
path open thereto, drain line 36 or, more preferably in normal
operation through the recirculation loop line 38, for example.
Drained water, which would alternatively flow through drain line
36, would then discharge to a sewer system (or to other optional
locations or apparatuses, e.g., it could flow back to the R/O unit
12, not shown). On the other hand, unused water flowed into and
through the preferred recirculation loop 38 will flow to and
through the recirculation inlet line 41 into tank 28, which as
above, preferably includes a sprayhead connection 52 for spraying
the inlet recirculation water into the tank 28.
[0034] Referring now again to FIG. 3, a more detailed description
of the use of sub-system 25 will be presented. Purified water flows
into sub-system 25 via inlet line 26 as connected by connection
member 42 to the main system supply line 14 (FIGS. 1 and 2),
preferably via a mating connection member 43 (FIG. 3). A check
valve 44 ensures forward one-way flow only into subsystem 25 and
the flow control valve 46 allows for a controlled maximum flow rate
of the water into the sub-system 25. When the unit is connected to
the main line 14 via connector 42, water flow may then be allowed
to proceed into tank 28. A float valve 50 can be used to stop
inflow of water when a preselected water level has been reached
inside tank 28. Outlet flow from tank 28 proceeds through outlet
line 30 to pump 32 which then pumps the outlet water to and through
outlet and supply lines 31, 33, respectively. When in use, water
may and preferably is also pumped through recirculation shunt line
40 back to recirculate into tank 28. Flow through this line 40 may
be operator-controlled as well by a shutoff or three way valve (not
shown). However, the preferred use of shunt line 40 provides the
user the ability to set the pressure that is supplied to the high
demand dialyzer reprocessing equipment through the flow from pump
32 to and through the sub-system line 33. The pressure regulator
assembly 61 can be set to an operating pressure according to
preferred reprocessing equipment manufacturer instructions
(typically 30 to 40 pounds per square inch (psi)), with the
regulated pressure being controlled by the valve 60 and indicated
on the pressure gauge 63 attached to the pressure regulating valve
assembly 61. Water will then flow from the pump 32 in a continuous
loop through this loop 40 and also then into and through sub-system
line 33 under a substantially common pressure set by the pressure
regulating assembly 61 (with a controlled transmembrane pressure
drop across filter 70). In either event, control over the operation
of pump 32 may be additionally aided by the two flow valves 67, 69
on the respective upstream and downstream sides of pump 32, to
shut-off flow as may be desired.
[0035] Flow through the sub-system supply line 33 preferably
receives one more purification step by flow through the dead-ended
ultrafiltration device 70. Pressure sensors 72 and 74 are used to
ensure that the pressures therein (particularly the transmembrane
pressure thereacross) do not exceed preselected levels. Though not
their primary purpose (which is sampling), stopcocks 76, 78 may
also be used in the monitoring and pressure control processes by
providing for relieving excess pressures or pressure differentials
as they may occur. As shown, filter 70 is the last mechanical
processing element in the flow path prior to the water use machine
outlets 34. This may thus provide further assurance of water purity
prior to actual use in the high demand machine or machines 20B. An
unshown alternative placement of filter 70 is in branch line 31
leading out of pump 32 prior to the branch off shunt line 40. This
placement would further ensure purification of water shunted
through loop 40 as well.
[0036] As mentioned, purified water exiting the filter 70 shown in
FIG. 3, then travels along supply line 33 and branches therefrom
through a respective branch connection 34 when a demand for water
is presented by a high demand device 20B connected thereto, the
respective valve 39 also being opened to permit flow therethrough.
Used water then flows out of that device 20B through the drain line
21 preferably to the sewer system (not shown).
[0037] Unused water at this point then travels preferably, as shown
in FIG. 3, through a recirculation loop 38 back to storage tank 28
via the inlet line 41 and sprayhead 52. The spray action creates a
preferably constantly moving air to water interface within tank 28,
especially along the interior surface thereof. Such movement
assists in reducing the likelihood of biological growth inside the
tank 28. Preferably also, some unused water is simultaneously
recirculated through shunt line 40. Pressure valve 60 is used
primarily to control the pressure of the fluid in outlet flow line
31 and the supply line 33, at least in that portion of supply line
33 which is directly upstream of filter 70. Then, so long as the
pressure drop across the membrane is sufficiently managed (through
monitoring thereof using gauges 72, 74), then the pressure of the
water flow through all of supply line 33 can be controlled to
present the proper operating pressures to the high demand device(s)
20B connected thereto. Note, during operation, recirculation is
preferably constant through both feed back lines 38 and 40 and pump
32 continually running regardless whether high demand device(s) 20B
are drawing water therefrom. Moreover, flow into tank 28 through
line 26 from main line 14 will preferably be more intennittent
wherein it is substantially constant until a minimum level of water
is achieved in tank 28 (even with water preferably continually
being pumped therefrom into the rest of the circuit sub-system 25),
but, then is turned off by the float valve 50 until a sufficient
draw by one or more devices 20B sufficiently lowers the operating
volume in tank 28. Such substantially constant recirculation flow
may, as preferred, enter tank 28 both near the top of tank 28
through a spray head 52 (from loop 38, e.g.) and simultaneously
dispersed in or near the bottom of tank 28 (from loop 40, e.g.) for
the purposes described above.
[0038] The intended purpose for the entire supply sub-system 25 is
as a "buffer" between a main supply line 14 fed by a treatment
(e.g., reverse osmosis (R/O) or de-ionization (DI)) machine 12
providing water at a constant rate, and one or more dialyzer
reprocessing machines 20B and/or other machine processes consuming
water at a variable and intermittently high rate. The reuse supply
sub-system 25 receives water from the R/O unit 12 at a constant
rate into a relatively small, preferably about a 30-gallon
reservoir 28 and, by means of a pump 32 (preferably a centrifugal
type) and a pressure control mechanism (see pressure regulating
valve/assembly 60/61), provides this water to dialyzer reprocessing
machines 20B at a constant pressure and variable rate. Even so, the
output capacity of the R/O machine 12 would still preferably exceed
the combined consumption rates of all dialysis applications
(machines 20A) and the average consumption rate of all dialyzer
reprocessing applications (machines 20B) operating
simultaneously.
[0039] The reuse supply sub-system 25 is preferably to be connected
to a purified water distribution main system (see system 10; FIG.
1) that supplies water meeting current Association for the
Advancement of Medical Instrumentation (AAMI) requirements for
dialyzer reprocessing (i.e., "AAMI Standard") and other AAMI
requirements as applicable (e.g., hemodialysis machines and
hemodialysis concentrate) as applicable.
[0040] In preferred operation particularly in a dialysis setting,
the AAMI standard water enters the sub-system 25 through a
two-piece stainless steel coupling known as a "quick disconnect"
including the water inlet connection 42 and the corresponding
outlet connection device 43. The main water distribution (R/O) side
of the quick disconnect preferably has a "female" connector 43 with
an internal shut-off valve (not shown), while the reuse supply
sub-system side of the quick disconnect has a "male" connector 42
with or without an internal shut-off valve. After passing through
the quick disconnect, water next flows through a check valve 44.
The check valve 44 prevents inadvertent backflow of water or
disinfectant chemicals from the reuse supply sub-system 25 into the
purified water distribution system 10.
[0041] Water next flows through flexible tubing line 26 and passes
through a flow control valve 46. The flow control valve 46
regulates water flow into the reuse supply sub-system 25 at a rate
that does not exceed R/O unit 12 output capacity. Typically, the
flow control valve 46 regulates flow to approximately one and
one-half (1.5) gallons per minute (gpm), although other sizes may
be provided according to individual requirements and
capacities.
[0042] Inlet water next passes through a float valve 50 before
entering the tank 28. The float valve 50 controls the maximum level
or height to which the tank 28 can be filled. Once the tank 28 is
full to the preferred, predetermined level, the float arm assembly
51 will shut off the incoming water supply to the tank 28.
[0043] The tank 28 is preferably constructed of polyethylene, has a
respective concave (dished) top and bottom, and a preferred maximum
capacity of about 30 gallons. The tank stand (not shown) is
preferably non-metallic and includes a pump mounting surface
directly below the tank 28. The top of the tank 28 has a larger
(e.g., six inch) threaded access port 55 that is hermetically
sealed closed preferably by a correspondingly sized (e.g.,
six-inch) threaded PVC cap preferably sealed with Teflon tape on
the threads. This opening is provided as a service and assembly
access port. It should not be opened under normal circumstances,
and should remain closed during operation to ensure a leakproof and
airtight seal. There is also a preferable two-inch port 56 fitted
with a levered male camlock and dustcap connector (not shown in
detail). The levers on the dustcap would allow it to be easily
opened and closed. This port 56 provides easy access for adding
chemical disinfectants to the sub-system 25. Properly attached, the
dustcap makes an airtight seal. Other elements adjacent and/or
connections to the top of the tank 28 are preferably disposed at
the spray head inlet line 41, the Pressure Relief Valve (PRV) 60
inlet line 62 and the vent connection for the 0.2 micron air vent
filter 52. At the bottom of the tank 28 is a preferable one-inch
piping line connection from which water flows from the tank 28 into
water line 30 and the inlet to the pump 32.
[0044] At the bottom of the tank 28 is a valve 67 that when opened
allows water to flow to the pump 32. This valve 67 is primarily an
aid for servicing purposes and is not preferably used during
routine operations. The pump 32 is preferably yet only typically
capable of pumping up to 10 gallons per minute at 45 pounds per
square inch (psi). Other pumps, larger or smaller, may be used to
provide for various flow and/or pressure requirements; for example,
15 gallons may also be typical in a cleaning/sterilizing
environment for medical or other high quality uses. The output line
31 of the pump 32 is then preferably connected to a tee fitting to
split flows through sub-system supply line 33 and recirculation
shunt loop 40.
[0045] Thus, one side of the tee junction directs flow through
shunt line 40 to a Pressure Relief Valve (PRV) 60 and pressure
regulating assembly/gauge 61/63. In the preferred embodiment,
connected to extension line 62 inside the tank 28, is a downspout
65 (shown in dashed lines), which directs the flow to the bottom of
the tank 28 and disperses it to prevent formation of a vortex
(swirling). This may also help to avoid the possibility of air
getting into the pump 32 via such a vortex. The PRV assembly 61
allows the user to set the pressure that is supplied to the
dialyzer reprocessing equipment 20B via line 33. The regulator
should be set according to reprocessing equipment manufacturer
instructions, typically 30 to 40 psi (taking into account any
pressure drop between the pump 32 and the outlet(s) 34, e.g. across
filter 70), with the regulated pressure being indicated on the
pressure gauge 63 attached to the PRV assembly 61. Water will flow
in a continuous loop through the flow path defined by the loop 40.
Flow path 40 also preferably includes a stainless steel female
quick disconnect connection member 66, also referred to herein as
the recirculation connector 66, for use during rinse and
disinfection procedures (to be described below).
[0046] The other side of the tee junction out of pump 32 and line
31 directs flow through a subsystem supply line 33 which preferably
includes a FiberFlo.RTM. hollow fiber cartridge filter 70
(available from the Minntech Corp., Minneapolis Minn.) and then to
outlets for one or more dialyzer reprocessing machines 20B, a drain
valve/line 37/36 (dashed lines), a recirculation loop 38, and then
back into the tank 28 via a spray head assembly 52. The first
component downstream of the tee branch junction is a valve 69 that
can isolate flow from the storage tank 28 and PRV recirculation
shunt path 40 from the dialyzer reprocessing equipment outlets 34.
This is followed by a pre-filter pressure gauge 72, used to measure
pressure at the inlet of the filter 70. A sample port 76 has been
placed at or near the filter inlet to permit pre-filter sample
collection. The preferred filter 70 is the FiberFlo.RTM. filter
introduced above, 20 inches long (nominal) and is constructed of
polysulphone hollow fibers rated by the manufacturer to remove both
bacteria and bacterial endotoxin. The cartridge-style filter 70 can
be removed from the housing and replaced during routine maintenance
or when microbial or delta pressure monitoring (transmembrane
pressure taken from gauges 72 and 74) indicates a need for filter
replacement. The filter housing includes connections and/or sample
ports 80A and 80B at the top and bottom to either vent or flush the
housing (and could alternatively be used in an ultrafiltration
manner to provide a flow of a clean fluid on the on the opposing
side of the membrane therein, though not preferable here). A sample
port 78 has been placed at or near the filter outlet to permit
post-filter sample collection and follows (or may be followed by) a
post-filter pressure gauge 74. The pre- and post-filter pressure
gauges permit filter pressure drop monitoring/measurements (an
indicator of either fiber breakage or plugging) as well as of the
pressure being supplied to the reprocessing outlets 34. Although
the order of these outlets may vary, the first few outlets 34
following the filter assembly 70 may preferably be valved outlets
for pre-rinse, clean sink (clean water) connections. Then, the next
one or more outlets 34 are preferably valved outlets for dialyzer
reprocessing equipment 20B. Lastly, preferably the drain valve 37,
closed during normal operation, would allow for the operator to
drain the tank 28. Then, water returns to the tank 28 via the
recirculation loop 38 and the spray head assembly 52.
[0047] Various ancillary preferred operating procedures for the
preferred dialysis reuse machine sub-system 25 in connection with a
main circuit 16 will now be described.
[0048] The following is a system start-up procedure which presumes
power to the pump 32 is turned off, the tank 28 is empty, and has
been disinfected and rinsed.
[0049] First, the drain valve 37 should be verified as closed.
Then, the inlet water line 26 is connected to the water supply
quick connection via connect devices 42/43. The tank 28 will begin
to fill. Then, after the tank 28 is approximately one-third (1/3)
full, the pump switch may be turned to the on position, allowing
the pump 32 to run and circulate water. Pressure readings across
the filter 70 and at the pressure regulator gauge 63 should be
verified that they are within specifications. The tank will
continue to fill until the level is maintained by the inlet float
valve 50.
[0050] Then, at the end of the desired period of operation, a
system shutdown procedure includes draining the tank 28 as now
described after each desired period (e.g., a day) of use. In
particular, draining the tank 28 includes disconnecting the inlet
water line from the main line 14 by disconnecting member 42 from
member 43 and then connecting the inlet water line 26 to the
recirculation connector 66 for connecting the sub-system 25 the
position shown in FIG. 4. Then, the pump 32 is turned on and the
drain valves 67 and 37 are opened; and, the tank level is observed.
Then, after the water drains out of the tank 28, the pump 32 is
turned off. Note, the pump 32 should not be run after the tank 32
has been drained, as air could then enter the pump 32, and then
damage to the pump 32 may result.
[0051] The reuse supply sub-system 25 should preferably be left
with the water supply quick connection 42 plugged into the
recirculation connector 66 at the end of each period's (e.g.,
day's) use. Overflow of the tank 28 or damage to the reuse supply
sub-system 25 may result if in instances where an R/O system has
the capacity for heat disinfection and if the water supply quick
connection 42 is left connected to the R/O main line distribution
loop 16.
[0052] Another set of ancillary procedures include disinfection and
cleaning. In exterior cleaning, the unit 25 should first be
unplugged from the power (preferably 120 V) connection (not shown).
Then, non-electrical exterior surfaces may then be cleaned
preferably with a 1% Renalin.RTM. or other peracetic acid cleansing
solution. A spray disinfectant solution should not be sprayed on
the power switch, motor or like electrical components. These may be
wiped with a damp cloth containing water only.
[0053] In periodic, preferably weekly, disinfection of the tank 28
and fluid pathways (pipe or tubing lines); first the tank 28 should
be drained or filled, as needed, so that the tank level is
preferably approximately one-third (1/3) full. (If draining the
tank 28, it will be preferred and/or necessary to disconnect the
water inlet line 26 from the main water supply 14 (to halt further
inflow from main line 14), and then reconnect it to the
recirculation connector 66 in shunt loop 40; see FIG. 4.) Then, the
power to the pump 32 should be turned off, and, the inlet water
line 26 should be verified as connected to the recirculation
connector 66 as shown in FIG. 4 and the drain valve 37 as closed.
Then, the cap to the disinfection port 56 at the top of the tank 28
is removed, preferably by lifting the locking arms (if such a
mechanism is used) on the sides of the cap. Preferably,
approximately one-half (1/2) a quart of Renalin.RTM. or like
peracetic acid disinfectant is poured into the tank 28 through the
access port 56. It is cautioned that appropriate Personal
Protection Equipment (PPE) should be used to prevent peracetic acid
exposure to skin or eyes. Then, the disinfection port cap is
replaced over the port 56 and locked in place by pressing the
locking arms (if used) down all the way. Again, other locking means
may be used to lock the disinfectant access port cap onto/over the
port 56, preferably in an airtight sealed relationship.
[0054] Next, the pump 32 will be turned on, and the sub-system 25
should be allowed to recirculate, preferably for about a minimum of
five (5) minutes. A small container (not shown) may then be placed
under the pre-rinse and/or clean water connections (i.e., the
preferable first one or more connections 34 after the outlet from
filter 70; also known as spigots 34A, or valved spigots 34A; see
FIG. 4), and then the valved spigots 34A slowly opened to allow the
disinfectant to flow out of the each such spigot 34A. A hose (not
shown) attached to each such spigot 34A may also be used. These
last few spigot opening steps should then be repeated for any other
valved connections on line 33, including any clean water spigot
(not separately shown), or any such connections 34 (see FIG. 3,
e.g.), including the re-use connections 34, particularly those not
connected to a re-use or other high demand machine. However, the
opening of the valved connections 34 which are connected to a
re-use machine (such as connection 34B connected to machine 20B in
FIG. 4) may also be desirably opened to run disinfectant solution
therethrough at this point in the procedure as well, even though
the disinfectant solution would then be destined to be flowed into
the high demand machine 20B (disinfection thereof would follow the
manufacturers' suggestions/requirements, but could be run
simultaneously or close in time with disinfection of the rest of
the sub-system 25).
[0055] To then conclude the circulation of the disinfection
solution through sub-system 25, first a test of the solution
potency or concentration at the sample port 78 downstream of the
filter 70 and the pre-rinse and clean water spigots 34A is run
using a test strip recommended by the peracetic acid manufacturer.
The results of this test are recommended to be positive
(.gtoreq.500 ppm of peracetic acid). Then, the pump 32 can be
turned off, and the sub-system 25 may now be allowed to dwell for a
down/inoperative period, such as overnight or for over-the-weekend
storage. The minimum dwell time for storing the sub-system 25
filled with peracetic acid solution is preferably about two (2)
hours.
[0056] The following tank and fluid pathways rinsing steps may then
be followed after disinfection (and a preferable minimum dwell
time, e.g., 2 hours; see above), assuming preferably that the above
disinfection solution circulation steps (or the like) had
previously been taken.
[0057] The operator first verifies that the inlet water line 26 is
connected to the recirculation connector 66, as shown in FIG. 4.
Then, the tank 28 is drained using the following sub-steps. The
pump 32 is turned on, the drain valve 37 is opened, and then, the
tank level is monitored, until the water and disinfectant solution
is drained out of the tank 28. Then, the pump 32 is turned off,
again cautioned to not run the pump 32 after the tank 28 has
drained, as damage to the pump 32 may result.
[0058] Next, the inlet water line 26 is connected to the main water
supply line 14 via the quick connection member 42 at a branch 18
(see completed schematic connections in FIGS. 1 and 2, e.g.). Then,
the tank 28 will begin to fill with purified water from the
purified water main system 10 through line 26. The sub-system drain
line 37 is also closed. The tank 28 is allowed to fill until it is
approximately one-third (1/3) full (the tank drain valve 67 may
also be closed temporarily during initial filling process, then
opened). Then, the pump 32 is turned on.
[0059] The pre-rinse and clean water spigots 34A (see FIG. 4) are
next opened briefly to allow some fresh water to flush through
these spigots 34A. A container or a hose (neither shown) may be
used (or needed) to catch the water leaving each such spigot 34A if
it is not so situated as to drain directly into a sink or like
receptacle (not shown). The drain valve 37 is then opened. And, the
tank level is then monitored. After the water drains out of the
tank 28, the pump 32 is turned off. Again, the pump 32 should not
be operated after the tank 28 has drained, as damage to the pump 32
may result. These last several steps (from filling the tank 28 and
rinsing through the sub-system 25) are preferably repeated until a
negative test (.ltoreq.3 ppm of the disinfectant cleaning solution,
such as Renalin.RTM. or equivalent peracetic acid) for the presence
of the disinfectant solution (Renalin.RTM./peracetic acid) is
obtained at the post-filter 70 sample port 78 and/or the prerinse
and clean water spigots 34A, or the like.
[0060] The following disinfection steps are particularly
additionally applicable when using a portable R/O unit (not
separately shown) as the main supply system purification unit 12
(see FIG. 1). The portable R/O unit 12 should first be verified as
turned off. The reuse supply tank 28 should then be drained as
indicated in the steps set forth above (turning on the pump 32,
opening the drain valve 37 and monitoring the tank level). Then, a
disinfection procedure of the portable R/O unit 12 may be performed
preferably per the manufacturers' guidelines. Peracetic acid based
disinfectants should preferably be used. Then, upon completion of
the portable R/O disinfection process, the reuse supply tank 28 is
drained of any water that may have entered the tank 28 as a result
of the portable R/O disinfection process. Then, the reuse supply
tank 28 and the rest of sub-system 25 are disinfected and rinsed as
described above.
[0061] Various preferred maintenance procedures will now be
described.
[0062] The steps for replacing the preferred filter 70 will now be
described. When, as measured by the respective pressure gauges on
opposing sides of the filter 70, the differential (transmembrane)
pressure across the preferable membrane (hollow fiber, plate or
otherwise) filter 70 exceeds the manufacturers' recommendation, or
a recommended time period has been reached, or when microbial
monitoring indicates the desirability thereof, the filter 70 may be
changed as follows. (Note, the preferred filter 70 is a
FiberFlo.RTM. Hollow Fiber Cartridge filter, manufactured by the
Minntech Corporation, Minneapolis, Minn. FiberFlo.RTM. is a
registered trademark of the Minntech Corp. Hollow fiber cartridge
filters of this type have also been known as ultrafiltration
devices or ultrafilters, and such and other alternative filters are
also intended to be useful herein as well.)
[0063] First, the sub-system supply tank 28 should be drained
and/or at least the valve 67 may be closed. The filter 70 housing
can then be drained using the connection spigot 80B at the bottom
of the housing. The filter 70 housing can then be opened and the
filter membrane can be removed (in the preferred FiberFlo.RTM.
filter, a simply removable and replaceable cartridge simplifies
this removal). A filter wrench (not shown) may make it easier to
open the housing. A new filter membrane (and/or cartridge) may then
be installed and the housing closed and sealed shut. The inlet
water line 26 may then be connected to the main water supply line
14 via the quick connector device 42 at a branch 18 as described
above. The tank 28 is then filled, preferably to about one-third
(1/3) full, at which point the pump 32 is preferably turned on. The
filter 70 is then preferably flushed according to manufacturer
guidelines. A disinfection procedure may then preferably be
performed of the sub-system supply tank 28.
[0064] The replacement of the preferred vent filter 54 is
manufacturer recommended at a replacement interval of six (6)
months when used regularly in the application described herein
above. The preferred vent filter 54 is a five (5) inch 0.2 micron
vent filter is manufactured by Waterlink Technologies of West Palm
Beach Fla. The replacement includes the draining of the re-use
supply tank 28 first, and then includes unscrewing the filter
housing (not separately shown) and removing the filter. Then the
new filter is installed and the filter housing is replaced and
tightened.
[0065] The pressure regulator 61 adjustment process usually
involves filling the tank 28 until it is at least about one-third
(1/3) full and then turning the pump 32 on. The regulator 61 may
then be adjusted until the pressure reading on the PRV gauge 63
reads the preferably pressure for supply to the supply line 33 and
the high-demand machines 20B; here, preferably about thirty to
forty (30-40) psi.
[0066] A preferred long term storage procedure will now be set
forth. The tank 28 should first be disinfected per the above
instructions, leaving a 1% peracetic acid disinfectant solution in
the tank 28 and in the fluid pathways 26, 30, 31, 33, 38, and 40,
inter alia. The pump 32 may then be unplugged from the power (120
V) connection (not shown). The 1% peracetic acid disinfectant
solution may preferably be replaced every two weeks per above
instructions. For storage intervals greater than one (1) month, the
system should be fully drained of liquid and the FiberFlo.RTM.
filter 70 removed. Upon removal from this storage, a new
FiberFlo.RTM. filter 70 should be installed and then the system
should be disinfected again per the above instructions.
[0067] Various warnings and/or cautions should now be addressed.
For example; the reuse supply system may preferably be disinfected
with Renalin.RTM., Minncare.RTM. (Renalin.RTM. Minncare.RTM. and
FiberFlo.RTM. are registered trademarks of Minntech Corporation,
Minneapolis, Minn.) or other peracetic acid solutions of like
concentration that have been diluted in a ratio of 1:100 with
purified water meeting the current requirements of the Association
for the Advancement of Medical Instrumentation (AAMI) for dialyzer
reprocessing. Always follow manufacturer's recommendations for the
handling, storage and use of peracetic acid solutions, including
those given for potency and residual testing.
[0068] And, as a point of caution, it should be noted again that
the pump 32 should not be operated with an empty tank 28. Operation
of the pump 32 with an empty tank 28 will damage the pump unit.
[0069] Also, various alternative embodiments may be available. In
one or more alternative embodiments (not shown), the two
recirculation loops 38, 40 may be connected to each other prior to
entrance into the tank 28. Thus, they could then both be connected
to a sprayhead 52 or to a mere inlet extension 62 or even to a
downspout 65. Nevertheless, such a connection is not preferred
because the separate functionalities of both the sprayhead 52
(agitating the water/air surface in tank 28) and the downspout 65
(counteracting any vortex action at the exit from tank 28) are
preferably retained in the preferred embodiment. Furthermore, the
outlet pressure of pump 32 is controlled by the pressure regulating
valve/assembly 60/61. In another alternative embodiment, the
recirculation loop(s) 38, 40 could be connected to inlet line 26,
and then the recirculation inlet to tank 28 could be defined as
identically indistinct from the primary inlet 48. Thus, there could
be only one inlet line, with the recirculation line(s) connected to
the main supply connection line 26. However again, the separate
functionalities of the separate inlets is preferred. Note, as
preferred, the inlet flow from the main line 14 through line 26 is
controlled to a maximum draw rate from line 14 by the control valve
46, and this inlet flow will preferably be stopped by the float
valve 50 when a sufficient maximum volume is detected in the tank
28. However, it is preferred that during operation, a continuous
flow of water cycles through the feedback loops 38, 40 to provide a
continuous spray of water spraying through sprayhead 52 and a
continuous vortex counteraction from downspout 65 (so air does not
reach pump 32).
[0070] Moreover, as a further aid to prevention of microbiological
growth, an alternative embodiment ultrafiltration device (not
shown), perhaps like ultrafilter 70, may be disposed in and
adjacent either of the tank inlets for recirculation lines 38, 40
just prior to re-entry of recirculating water into tank 28.
Disposition in either or both of these inlet lines provides for
ensuring the purification of the water recirculated through either
recirculation loop 38 or shunt 40. Otherwise, similar ultrafilters
could separately be placed in other locations in either or both of
these recirculation loops 38 and/or 40. Another alternative
placement of an ultrafilter 70 is in pump outlet line 31 to ensure
contamination free flow after pump 32 regardless whether the flow
is shunted through line 40 or run through supply line 33, drained
or looped back through line 38. However, outlet pump pressure
control using a pressure regulating valve/assembly 60/61 would not
be a direct control if situated downstream of such a filter 70, and
may not be as effectual as in the preferred embodiment.
Furthermore, depending primarily upon capacity, parallel
dispositions of ultrafiltration devices such as device 70 may be
established to ensure a sufficient quantity of flow through the
filtration portion of the sub-system circuit.
[0071] A couple of further possible alternatives could involve pump
controls (not shown). For example, high and/or low water sensors
disposed inside the tank 28 could signal respective high and or low
water levels which could then be converted into control signals to
either turn the pump 32 on or off. For example, a low water sensor
(not shown) could be disposed to sense when too little volume
remains inside tank 28, and therefore sends a signal which is
ultimately used to turn the pump 32 off (effectively, a low-water
cut-off device to stop the pump). A pump protective higher sensor
in tank 28 could then be used to indicate that a sufficient minimum
quantity of water is disposed inside tank 28 so that it would be
safe (low or no opportunity for air entry therein) then to turn on
pump 32. The signal could itself be converted to control pump 32. A
similar high water level sensor could similarly be used in lieu of
(or as a fail safe in addition to) the float valve 50 to halt flow
into tank 28. As a more particular (yet, non-limiting) example of
this, a sensor and valve configuration could be used to actually
halt the flow of water into the tank at a high level point. A
normally closed valve (e.g., a valve which is closed when no power
is provided thereto) may be used in conjunction with a high level
sensor such that when no water is in contact with the sensor, power
is allowed to be continually provided to the valve so that the
valve is in an open state to provide continual inflow of water into
the tank. Then, when the tank fills sufficiently such that water
does reach and contact the sensor, the sensor provides a signal
(preferably through a relay or like device) to halt power to the
valve, which then closes and thereby stops flow of water
therethrough and into the tank. Such a valve could also be
connected to the power supply to entire system, whereby halting
such power to the overall system, would then also cut off power to
the valve so that the valve then closes. This could then act as a
failsafe in case overall power is unexpectedly lost, and/or could
act as a regular (e.g., nightly) flow stoppage mechanism, for
example, when operation is to be ended at the end of each day, then
turning off the overall power will then shut the valve off and stop
the flow of water into the tank. In this way, then, water flow in
loop 16 need not be stopped at the end of each day, nor would
system 25 need to be disconnected therefrom, even if loop 16 is
disinfected or otherwise has other flows therethrough after normal
operation.
[0072] The pump 32 could also have characteristics allowing for
increasing pump output if it sensed that the re-use or like high
demand machines 20B were demanding such quantities of water that
they might overwhelm the present pump output. The pump may then
include the necessary internal elements for sensing the need for a
greater output, and/or there could be disposed certain pressure
and/or flow meters or the like (not shown) in the respective flow
lines, e.g., sub-system supply line 33, to provide feedback to the
pump 32 to start, stop or change output, positively or negatively
as needed.
[0073] The present invention may take many forms in distribution or
the like. For example, the present invention may involve
distribution of a sub-system kit which may be incorporated later
in/on an otherwise substantially independent main water supply
system. Advantages in expense and/or automation may be realized
here. Alternatively, the sub-system may be manufactured and
distributed as part of an entire water supply system which includes
the main supply line with or without water purification
devices.
[0074] As noted, systems of the present invention may be highly
beneficial in numerous water supply systems including those
requiring purified water such as in medical applications like
dialysis, or may also be useful in pharmaceutical preparation or
electronics manufacturing or other water supply processes. In each
of these or other uses, the present invention handles the delivery
of water in a main loop for relatively low, often substantially
constant demand devices together with the delivery through a
sub-system of relatively higher demand water usually at more
intermittent intervals. It should also be noted that the present
invention may be used with or without purification water supply
systems.
[0075] Also, though it may be noted that the present invention
handles pressure fluctuations which may be incurred by having both
low and high demand water using devices on a water supply line; the
present invention may also be directed to handling other water
handling issues as well. For example in the medical dialysis field,
heat issues may be handled by the present invention. Heat
sterilization of a main water supply line or loop is common in the
dialysis water supply field; however, heat sterilization processes
are not compatible with state-of-the-art re-use machines. The
present invention effectively isolates the re-uses machinery from
the main loop so that the re-use machines are not exposed to the
high temperature water (or other fluid) flowing through the main
loop. Similarly, it is common situation that re-use machines are
preferably disinfected using a chemical solution or disinfectant,
and the present invention provides an isolated ability to provide
such a chemical to the re-use and/or other dialyzer pre-use
cleaning or like equipment connected to the sub-system. The
chemical solution or disinfectant may be placed in the smaller
storage tank of the sub-system and circulated throughout the
sub-system as shown for example in FIG. 4 in an isolated manner
separately from the disinfection/sterilization process of the main
system (which as described here, could be heat-based).
[0076] Accordingly, a new and unique invention has been shown and
described herein which achieves its purposes in an unexpected
fashion. Numerous alternative embodiments readily foreseeable by
the skilled artisan, which were not explicitly described herein are
considered within the scope of the invention which is limited
solely by the claims appended hereto.
* * * * *