Tap water powered water recirculation system

A water recirculation system which derives energy from an available pressurized tap water supply to filter and return previously discharged water to a water discharge device. A system embodiment includes a shower head and a tap water powered pump for returning water discharged from the shower head to the pump for mixing with the supplied tap water for delivery to the shower head inlet.

FIELD OF THE INVENTION 
This invention relates generally to tap water powered water recirculation 
systems and more particularly to shower water delivery systems modified to 
recirculate discharged shower water. 
BACKGROUND OF THE INVENTION 
Water shortages frequently occur in many parts of the United States and the 
rest of the world. As a consequence, considerable effort has been expended 
to develop low water utilization devices such as low flow shower heads, 
toilets, etc. Many municipalities in California, for example, encourage or 
mandate the use of toilets which use less than 2.0 gallons per flush and 
shower heads which discharge less than 3.0 gallons per minute. Various 
such devices are widely commercially available and are described in the 
literature. In general, although such devices perform adequately, they 
usually do not function as well as conventional full flow devices. For 
example, whereas conventional full flow shower heads typically discharge 
3.0 to 8.0 gallons per minute, low flow shower heads which discharge less 
than 3.0 gallons per minute, are often perceived as being weak and only 
marginally satisfactory. 
The present invention is directed to plumbing systems utilizing a 
pressurized tap water supply for enhancing water delivery, without 
consuming additional supply water, by recirculating a portion of the 
previously discharged water. 
The concept of recirculating discharged shower water has been known for 
many years primarily for use, for example, in boats, trailers, motor 
homes, and the like; e.g., 
______________________________________ 
U.S. Pat. No. Inventor 
______________________________________ 
1,065,265 Nordmark 
2,308,452 Ortyl 
3,606,618 Veech 
3,646,618 Johnson 
4,224,700 Bloys 
4,413,363 Troviano 
4,828,709 Houser 
4,893,364 Keeler 
______________________________________ 
These systems typically use electric motor driven pumps for recirculating 
discharged shower water to a shower head. A portable shower stall system 
utilizing a water driven pump to transport water from a base to a 
sink/drain is discussed in U.S. Pat. No. 4,975,992. 
SUMMARY OF THE INVENTION 
The present invention is directed to a water recirculation system which 
derives energy from an available pressurized tap water supply to filter 
and return previously discharged water to a water discharge device, such 
as a shower head. As an example, embodiments of the invention are able to 
discharge water from a shower head at a flow rate which exceeds twice the 
flow rate of the tap water supplied to the shower head, which might be on 
the order of 1.5-2.0 gallons per minute. Thus, although a shower delivery 
system consumes tap water at a low flow rate consistent with water 
conservation objectives, it nevertheless delivers a full flow rate to a 
user. 
Water recirculation systems in accordance with the invention are 
characterized by a water discharge device, e.g., a shower head, and a tap 
water powered pump for returning water discharged from the discharge 
device for mixing with supplied tap water for delivery to the discharge 
device. 
Preferred embodiments of the invention particularly suited for after-market 
shower water delivery systems, both for stall shower and bathtub 
configurations, are described hereinafter. A concurrently filed U.S. 
patent application, Ser. No. 07/754,606 entitled "Tap Water Powered Shower 
Water Recirculation System", whose disclosure is by reference incorporated 
herein, describes embodiments particularly suited for new installations, 
both for stall shower and bathtub configurations. 
In accordance with preferred embodiments of the invention, the tap water 
powered pump comprises a jet pump incorporated between a tap water supply 
pipe and a shower head. The pump includes a tap water supply inlet, a 
return water suction inlet, and a water discharge outlet. 
In accordance with a preferred embodiment, a pooling means is provided 
which cooperates With an existing drain of a stall shower or bathtub to 
dam or block the drain to thus pool a portion of the water discharged from 
the shower head. A preferred pooling means is configured as a drain 
adapter and incorporates a drain overflow path to limit the height of the 
pool. 
In accordance with an important feature, the preferred drain adapter 
includes filter means, e.g., open cell foam, for filtering water returned 
from the pool to the pump's return water suction inlet. 
In accordance with another feature of one preferred drain adapter, a 
leakage path is defined for automatically depleting the pool after a user 
terminates his shower. 
In accordance with an alternative after-market drain adapter, the drain 
adapter wall section for blocking the drain can be selectively positioned 
in either a closed position or an open position. 
In accordance with a further alternative, an after-market drain adapter 
particularly suited for use in stall showers, is configured as a flat mat 
upon which a user can comfortably stand. 
A tap water powered pump in accordance with the invention preferably 
comprises a jet pump including a driving nozzle responsive to tap water 
supplied to its supply inlet for discharging a high velocity stream 
through a suction chamber. The pump's suction inlet opens into the suction 
chamber thus enabling pool water to be drawn into the suction chamber and 
mixed with the stream for discharge through the pump's discharge outlet. 
In accordance with a preferred embodiment, the jet pump is housed within a 
pipe section mounted in essentially the same manner as a standard shower 
arm. 
In accordance with an important feature of the preferred jet pump, a 
unidirectional valve is provided between the pump's supply inlet and its 
return water suction inlet to prevent backflow into the tap water supply 
plumbing.

DETAILED DESCRIPTION 
Attention is initially directed to FIGS. 1a and 1b which illustrate a 
preferred embodiment of a tap water powered water recirculation system in 
accordance with the invention used in conjunction with an otherwise 
conventional shower/bathtub installation. Such installations typically 
include hot and cold tap water supply pipes 20, 22 coupled to a fitting 
24. Valve handles 26, 27 respectively control valves (not shown) which 
enable a user to establish the respective flow rates from pipes 20, 22 to 
fitting 24, and thus the temperature of the water delivered to pipes 28 
and 30, respectively coupled to bathtub spout 32 and elbow 36 adapted to 
threadedly receive the end of a conventional shower arm through opening 38 
in wall 40. A diverter valve 41 in spout 32 determines whether the tap 
water is supplied to the spout 32 or elbow 36. 
The bathtub spout 32 is mounted to discharge into a bathtub 42 essentially 
defined by a floor 44 and a peripheral wall 46. The floor 44 defines a 
drain opening 48 communicating with a drain path including pipe 50 coupled 
to waste pipe 51. The vertically oriented peripheral wall 46 is generally 
provided with an overflow opening 52 which communicates with overflow pipe 
54 which opens to the waste pipe 51. A valve handle 56 is typically 
mounted proximate to the overflow opening 52 for controlling flow from the 
drain pipe 50 to the waste pipe 51, i.e., the handle can either be in an 
open position to drain water from the bathtub 42 or a closed position to 
fill the bathtub from water discharged from the spout 32. 
As previously noted, the elbow 36 in a typical shower/bathtub installation, 
receives a threaded first open end of a shower arm pipe, terminating at a 
shower head for discharging a shower spray upon a user standing on the tub 
floor 44. In order to conserve water, state of the art low flow shower 
heads discharge less than 3.0 gallons per minute, which many users feel is 
insufficient to provide a satisfying shower experience. The present 
invention is directed to a tap water powered water recirculation system 
which enables a water discharge device, e.g., a shower head, to discharge 
a flow rate greater than the tap water supply flow rate delivered by 
supply pipe 30 to elbow 36. FIGS. 1-5 show a water recirculation system 
embodiment in accordance with the invention incorporated in an existing 
shower/bathtub installation. The water recirculation system as depicted in 
FIG. 1a is essentially comprised of a water pooling means in the form of 
drain adapter assembly 60, a return tube 62, and a pump assembly 64, 
preferably contained within a pipe section 66 coupling supply elbow 36 to 
shower head 68. 
Attention is now directed to FIGS. 2a and 2b which illustrate the details 
of a preferred pump assembly 64 and drain adapter assembly 60 in 
accordance with the invention. The pump assembly includes a pipe arm 66 
having a first open end 70 externally threaded at 72 into the supply elbow 
36. A second externally threaded open end 74 is intended to receive an 
internally threaded collar 76 of the shower head 68. Additionally, the 
pipe arm 66 defines an intermediate opening 80 within a nipple 82. 
A tubular member 83 is internally formed to define a converging driving 
nozzle 84 having an entrance 86 and an exit 88 is mounted in the pipe arm 
66 proximate to the open first end 70. The nozzle exit 88 is positioned 
proximate to the converging mouth 90 of an elongated mixing tube 92 having 
an intermediate straight section 94 and a downstream diverging section 96. 
In response to pressurized tap water supplied from nipple 36 to the nozzle 
entrance 86, a high velocity water stream will be discharged from the exit 
88 to produce a suction in the region or chamber 98 proximate to the exit 
88 and mouth 90. The aforementioned pipe intermediate opening 80 opens 
into the suction chamber 98. The driving nozzle 84 is preferably 
dimensioned to deliver a flow rate limited to approximately 1.5-2.0 
gallons per minute for typical tap water pressures, i.e., above 40 pounds 
per square inch. Thus, the valve handles 26, 27 (FIG. 1b) are primarily 
used in accordance with the invention for the purpose of regulating the 
temperature of the water discharged from shower head 68, rather than for 
regulating its flow rate. 
An in-line screen 100 and unidirectional check valve 102 are preferably 
mounted in the tubular member 83 between the elbow 36 and the entrance 86 
to nozzle 84. The screen 100 is preferably comprised of screen material, 
e.g., shaped in the form of a truncated cone, mounted across a washer or 
O-ring 104. The O-ring 104 mounts against a block 106. The downstream side 
of the block 106 forms a valve seat 107, surrounded by O-ring 108, for 
receiving a ball valve element 110 urged into a seated position by coil 
spring 112. The screen 100 and check valve elements 102 are held under 
compression by a plug 113 threaded into end 70 of pipe 66. 
In response to pressurized tap water supplied to the open end 70 of pipe 
66, the water flows past screen 100 and check valve 102 into the entrance 
86 of nozzle 84. Exiting from the nozzle 84 at a high velocity, the water 
stream creates a suction in chamber 98 enabling it to draw water from 
return tube 62 into chamber 98 and the mouth 90 of mixing tube 92. The 
high velocity tap water stream exiting from nozzle 84 entrains the water 
drawn from return tube 62 resulting in a mixed water stream being 
delivered at the open end 74 of pipe 66. 
The depicted shower head 68 can be a conventional full flow shower head 
capable of delivering at least twice the flow rate delivered by driving 
nozzle 84. The shower head 68 is comprised of the internally threaded 
collar 76 shown mounted on the external threads of the pipe end 74. A ball 
element 112, mounted on collar 76, is received in socket block 114 
enabling it to swivel on the fixed ball element. The socket block 114 is 
depicted as being coupled by threads to a collar 118 which may be formed 
integral with the shower head body 120. A screen washer 122 is preferably 
mounted within the collar 76 in line with a water inlet passageway 124 
defining the water path from the pipe end 74 to outlet openings (not 
shown) in the shower head body 120. 
A decorative trim plate 128 is preferably mounted on the pipe 66 for 
engagement with the outer surface of wall 40. 
The drain adapter assembly 60 depicted in FIG. 2 and shown in greater 
detail in FIGS. 4 and 5 functions in conjunction with the floor mounted 
drain opening 48 to form a pool 130 of water discharged from the shower 
head 68 to enable water to be returned by pump 64, via return tube 62, for 
mixing in the aforementioned mixing tube 92. The preferred drain adapter 
60 primarily includes a housing 150 defining a dam wall 151 comprised of a 
fixed section 152 and a movable section 154, a bottom cover plate 158, and 
a piece of filter material 160. 
More particularly, the housing 150 is depicted as being essentially 
triangularly shaped having a top plate 162 defining a suction outlet 
nipple 164 defining a suction outlet or return opening 166. The opening 
166 through the nipple 164 opens into a pooling chamber 168 defined 
between the top plate 162 and the bottom cover plate 158. An outer series 
of arcuately arranged fingers 170 is formed in the housing 150 depending 
from the top plate 162. The fingers 170 are made to be somewhat resilient 
and have outwardly extending end projections 174 which are intended to 
interlock with inwardly extending end projections 176 on accurately 
extending fingers 178 which project upwardly from bottom cover plate 158. 
The fingers 170 and 178 are correspondingly arranged to enable their 
respective projections 174, 176 to interlock for the purpose of holding 
the bottom cover plate 158 to the housing 150, while still enabling it to 
be readily separated by a user without tools for access to the filter 
material 160. 
The housing 150 preferably also includes an inner series of arcuately 
arranged fingers 184 spaced inwardly from the fingers 170 to define an 
arcuate channel 186 therebetween for accommodating the aforementioned 
filter material 160. The filter material 160 is provided to filter the 
water returned from the pool 130 to the pump 64 via return tube 62. The 
filter material 160 is preferably capable of removing hair and other 
particles, soap film, etc. from the water to be recirculated. It has been 
found that a small pore open cell foam material functions satisfactorily 
for this purpose. 
As previously noted, the housing 150 defines a fixed dam wall section 152 
comprising a substantially cylindrical wall having a small inwardly turned 
lower lip 190. In use, the drain adapter 60 is intended to be placed on 
the bathtub floor 44, held in place by suction cups 192 or other suitable 
fastening means, with the fixed dam wall section 152 aligned with the 
drain opening 48. The movable dam wall section 154, received within the 
fixed dam wall section 152, has an outer diameter dimension which fits 
closely within the inner diameter of the lip 190, but with sufficient 
clearance to enable it to move axially relative to the fixed dam wall 
section 152. This enables dam wall section 154 to self locate its bottom 
surface 196 against the floor surface 44 or drain fitting 198 defining the 
drain opening 48. The lower surface 196 of the movable dam wall section 
154 may be provided with small leakage openings 200 for the purpose of 
draining the accumulated water pool 130 after a user terminates his 
shower. 
In order to use the water recirculation system depicted in FIGS. 1-5, the 
drain adapter assembly 60 should be properly placed over the drain opening 
48 and the upper and lower ends of the return tube 62 should be 
respectively coupled to the nipple 82 on pipe 66 and the nipple 164 on 
drain adapter housing 150. With these elements in place, now assume that 
tap water is supplied via elbow 36 to driving nozzle 84 at a flow rate 
which will be assumed to be 1.5 gallons per minute. The supplied tap water 
discharged at a high velocity from driving nozzle 98 will create a suction 
within suction inlet 80, thus initially drawing air upwardly through 
return tube 62. However, as water is discharged from shower head 68, it 
will accumulate as pool 130 around the drain adapter assembly 60 because 
the aforementioned drain openings 200 are dimensioned to drain water at a 
substantially lesser rate than it is discharged from the shower head 68. 
For example, it has been found that a total flow rate through leakage 
openings 200 of about 0.25 gallons per minute is suitable. Thus, the 
difference between the assumed supply flow rate of 1.5 gallons per minute 
and the drain rate of 0.25 gallons per minute enables the pool 130 to 
initially accumulate at a rate of approximately 1.25 gallons per minute. 
As the pool grows, water will be drawn from the pool 130 by the suction 
communicated from the suction inlet 80 via tube 62 to the suction outlet 
166, through filter material 160 into the chamber 168 around outlet 166. 
Water from the chamber 168 will then traverse the return tube 62 to the 
pump's suction inlet 80. The return flow rate via tube 62 will increase, 
from zero to e.g., 1.5-2.0 gallons per minute, thus resulting in an 
approximate 3.0-3.5 gallon per minute discharge from shower head 68. The 
height to which the pool 130 will accumulate is limited by the height of 
the fixed dam wall section 152, as is best depicted in FIG. 2. That is, as 
the pool 130 increases in height, it will overflow the fixed wall section 
152, as is depicted by flow arrows 206, into the drain opening 48. In use, 
the user will control the temperature of the water discharged from shower 
head 68 via valve handles 26, 27. When the user terminates his shower, the 
pool 130 will drain off through the leakage openings 200 as is depicted by 
the flow arrows 210. 
Attention is now directed to FIGS. 6 and 7 which depict an alternative 
shower arm configuration in which a fixed pipe section 300 is coupled to a 
tap water supply pipe via nipple 36 and emerges from the wall 40. FIG. 6 
depicts a valve 304 mounted on the downstream end of pipe 300. Such valves 
304 are frequently used in severe water restriction areas in order to 
enable a user to turn the water flow off while he is lathering. In 
installations where such a valve is used to maximize water conservation, 
an alternative drain adapter assembly is employed, as depicted in FIGS. 
7-10, to prevent draining the accumulated water pool while the water flow 
discharge is temporarily stopped. Before describing the alternative drain 
adapter assembly 306, it should be noted that the shower arm assembly 
depicted in FIG. 6 further includes a fixed coupler element 308 intended 
to be threaded and operatively coupled to valve 304. A first swivel 
element 310 is operatively coupled to coupler 308, and is connected via a 
short pipe section 312 to a second swivel element 314. The element 314 is 
operatively coupled to swivel element 316 which in turn carries shower arm 
318 which incorporates a jet pump, as depicted in FIG. 7, corresponding to 
the jet pump 64 previously described in connection with FIG. 2. Pipe arm 
318 carries shower head 320 which can be identical to the aforementioned 
shower head 68. 
It will be recalled that the drain adapter assembly 60 of FIGS. 2, 4 and 5 
includes a movable dam wall section 154 which includes leakage openings 
200 to assure that the pool 130 drains after the user terminates his 
shower. In installations in which the user may want to temporarily 
terminate the shower head flow while lathering in order to maximize water 
conservation, use of the aforedescribed drain adapter assembly 60 would 
not be satisfactory because the leakage openings 200 could deplete the 
pool 130. Accordingly, an alternative drain adapter assembly 306 (FIGS. 
7-10) is provided which assures that the water pool 130 is accumulated and 
maintained even during an interval in which shower head flow temporarily 
ceases. The drain adapter assembly 306 differs from the aforedescribed 
assembly 60 in that its movable dam wall section 322 omits the leakage 
openings and has a continuous lower surface 323 adapted to fully seal 
against drain fitting 324. That is, when the dam wall section 322 is in 
its lower position as shown in FIG. 7, water discharged from the shower 
head 320 will continue to accumulate to form pool 130 to a height 
determined by the height of fixed dam wall section 325 after which it will 
overflow into drain opening 326 as represented by flow arrows 327. 
A handle 328 is affixed to the movable dam wall section 322 enabling it to 
be raised from its lower or closed position depicted in FIG. 7 to the open 
position depicted in FIG. 10 in which clearance is provided between the 
dam wall lower surface 323 and drain fitting 324, thus enabling pool water 
to drain into drain opening 326 as depicted by flow arrow 330. 
As is best shown in FIG. 8, the movable dam wall 322 is provided with first 
and second radially projecting ears 334, 335. An upper lip 336 on the 
fixed dam wall 325 is provided with corresponding openings 338 and 340 
through which the ears 334 and 335 can pass vertically. Thus, to move the 
dam wall section 322 from its lowered close position shown in FIG. 7 to 
its raised open position shown in FIG. 10, a user would grasp the handle 
328 and rotate it to align ears 334, 335 with openings 338, 340. The user 
can then lift the handle 328 to move the ears, 334, 335 through the 
openings 338, 340 and then rotate the handle as is suggested by arrows 346 
in FIG. 9 to retain the dam wall 322 in its raised position (FIG. 10). 
In the use of the alternative drain adapter assembly 306, the user will 
move the dam wall section 322 to its lower position prior to supplying 
water to the shower head 320. Thereafter, as water is discharged from the 
shower head 320, it will accumulate to form pool 130 and will be 
maintained even when the user temporarily shuts off the shower head flow, 
as by utilization of valve 304. When the user is finished showering, he 
will raise the dam wall section 322 to the position depicted in FIG. 10 to 
thus drain the pool 130. In other respects, the embodiment of FIG. 7 
operates similarly to the embodiment of FIG. 2. 
Attention is now directed to FIGS. 11-13 which depict the tap water powered 
water recirculation system particularly designed for use in conjunction 
with an existing shower stall installation. In contrast to a typical 
shower/bathtub installation where the floor mounted drain opening is 
generally located at one end of the bathtub, in a shower stall the floor 
mounted drain opening 400 is typically located at the center of the floor 
area. Because of this location, utilization of a drain adapter assembly 60 
(FIG. 2) or 306 (FIG. 7) would not be well suited for use in a shower 
stall. Accordingly, FIGS. 11-13 illustrate an alternative drain adapter 
assembly 402 comprising a housing 403 configured in the form of a flat mat 
upon which a user can stand. More particularly, the drain adapter assembly 
402 is comprised of a flat upper plate 404 preferably having a rubberized 
nonslip top surface. The plate 404 is supported on legs 406 which extend 
radially from a hub 408 depending from the lower surface of plate 404. The 
radially extending legs 406 rest on the floor 410 of the shower stall. The 
radially extending legs 406 essentially divide the underside of the 
housing 403 into multiple sector compartments 412. Openings 414 are formed 
around a perimeter support band 416 supporting the plate 404 at its 
peripheral edge. The openings 414 act as water inlets permitting water 
discharged from the shower head 417 to flow into the sector compartments 
412. Additionally, the upper surface of the plate 404 is provided with 
holes 418 which permit water discharged from the shower head 417 to enter 
the sector compartments 412. 
The hub 408 is defined by an outer annular wall 420 and an inner annular 
wall 422. The inner wall 422 is comprised of fingers 423 having outward 
projections 424. A cover plate 425 having fingers 426 with inward 
projections 427 cooperates with the fingers 423 to accommodate a piece of 
filter material 428. 
The hub region of the housing 408 further includes a dam wall 430 which 
surrounds the drain opening 400 to restrict flow into the drain opening. 
The dam wall 430 may be provided with leakage openings 432, analogous to 
the openings 200 in FIG. 2, for the purpose of automatically draining 
pooled water. As water pools around the dam wall 430, it can be pulled 
through the filter material 428 into pooling chamber 440 by suction 
communicated via passageway 442 defined between walls 444 and 446 
depending from the plate 404. At its outer end, the passageway 442 couples 
to a tubular extension 454 whose length can be selected so as to terminate 
adjacent the wall 456. The tubular extension 454 is adapted to be readily 
coupled to one end of the return tube 458, the other end of which is 
intended to be coupled to the suction inlet 460 of the pump shower arm 
assembly 462. 
In use, water discharged from the shower head 417 will fall on the upper 
surface of the plate 404 and then will enter the sector compartments 412 
via the holes 418. Additionally, water falling on the floor 410 outside 
the periphery 416 of the housing 403 will flow into the sector 
compartments 412 via the openings 414. This water will then flow toward 
the outer annular wall 420 and through the filter material 428 into the 
pooling chamber 440. Suction produced by the tap water powered pump 
assembly 462 via return tube 458 will draw water for recirculation via the 
passageway 442. The height of the water pool formed beneath the plate 404 
is limited to the height of the dam wall 430. That is, as the pool water 
level reaches the height of the dam wall 430, it will thereafter overflow 
through openings 464 in grill 466 mounted above the drain opening 400. 
Thus, the collected water pool is contained essentially beneath the upper 
surface of plate 404. The upper surface of plate 404 is preferably formed 
of a non-slip material comfortable to a user's feet. The leakage openings 
432 in dam wall 430 assure that when the user terminates his shower, the 
collected pool water will flow into the drain opening 400 via leakage 
openings 432. 
From the foregoing, it should now be appreciated that a water recirculation 
system has been disclosed incorporating a tap water powered pump which 
enables a water discharge device to deliver a flow rate considerably 
greater than the rate at which tap water is supplied. The invention finds 
particular utility in connection with shower stall or shower/bathtub 
installations for enabling a user to experience a high flow rate, e.g., in 
excess of 3.0 gallons per minute, while taking a lesser flow, e.g., 
approximately 1.5 gallons per minute, from the tap water supply. Although 
the preferred embodiments disclosed herein utilize a jet pump incorporated 
within a pipe arm supporting a shower head, it should be recognized that 
other types of tap water powered pumps could be utilized. It is also 
pointed out that although it is particularly convenient to locate the tap 
water powered pump within the shower pipe arm as depicted in the disclosed 
embodiments, the pump could, in accordance with the invention, be mounted 
anywhere between the return opening (e.g., 166) and the shower head inlet, 
as for example, closer to the drain adapter assembly. 
Moreover, although preferred drain adapter assemblies have been disclosed 
herein for pooling discharged water, it should also be recognized that 
many alternative means could be used for returning water to the discharge 
device. For example, in a rather simple embodiment, the drain opening 
could merely be closed, as by a stopper or existing valve, and the shower 
stall pan or bathtub could be used to pool water, with the lower end of 
the return tube (e.g., 62) hanging into the pool. 
It should also be understood that although the shower installations 
depicted herein have included only a single shower head, embodiments of 
the invention would of course also be useful in multiple head 
installations in which a single pump could return water to multiple heads 
or a separate pump could be provided for each head.