RESERVOIR SOUS PRESSION

PRESSURE TANK

Abrégé français

Un ensemble de réservoir sous pression sert principalement dans un système de tuyauterie raccordé à un puits ou à un autre système d'approvisionnement en eau et comprend un réservoir contenant une vessie et une bague autour de la vessie dans le réservoir, à mi-chemin entre ses extrémités du haut et du bas. L'eau est introduite dans la bague et versée dans le réservoir par des trous au fond de la bague. L'eau à usage domestique est extraite du haut du réservoir. Les sédiments sont éliminés par un drain au bas du réservoir.

Abrégé anglais

A pressure tank assembly for use primarily in a plumbing system connected to a well or other water supply system includes a tank containing a bladder and a ring around the bladder in the tank midway between the top and bottom ends thereof. Water is introduced into the ring and discharged into the tank via holes in the bottom of the ring. Water for domestic use is drawn from the top of the tank. Sediment is removed through a drain in the bottom of the tank.

Revendications

CLAIMS:
1. A pressure tank assembly including a tank having a side wall, a top wall
and a
bottom wall; an inlet in the tank for introducing water into the tank; a
tubular ring in the
tank midway between said top and bottom walls for receiving water from said
inlet; a
plurality of outlet offices in the bottom of said ring for discharging water
into the tank; a
first outlet in the top wall of the tank for discharging water from the tank
for use; an
expansible bladder in the tank; a valve in the bladder extending out of said
top wall for
admitting or discharging air from said bladder, a second outlet in the bottom
wall of the
tank for discharging sediment from the tank; and a cage above said second
outlet
connected to a bottom end of said bladder for maintaining the bladder in a
fixed
position above the bottom wall and permitting the escape of water-borne
sediment from
the tank via said second outlet.
2. The pressure tank assembly of claim 1 including a manifold in said top wall
of
the tank, said manifold containing said inlet, said first outlet and said
valve.
3. The pressure tank assembly of claim 2, wherein said side wall of the tank
is
cylindrical, and the top and bottom walls are hemispherical, and said inlet
extends from
said manifold and along the interior of said top and side walls to one side of
said ring.
4. The pressure tank assembly of claim 2, wherein the side wall of the tank is
cylindrical, and the top and bottom walls are hemispherical, and said inlet
extends
through said side wall to one side of said ring.
5. The pressure tank assembly of claim 3 or 4 including a non-corrosive wire
or
chain connected to said manifold and to a second side of said ring opposite
said one
side for maintaining said ring in a horizontal position in the tank.
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Description

CA 02685803 2009-11-18
PRESSURE TANK
FIELD OF THE INVENTION
This invention relates to a pressure tank. More specifically, the invention
relates
to a pressure tank for use in a plumbing system which includes a pump for
pumping
water from a well or a body of water such as a lake, dug out, cistern or a
river.
DESCRIPTION OF RELATED ART
Pressure tanks are by no means new. With conventional pressure tanks
presently available in the marketplace, water is introduced through an inlet
pipe (supply
line) and a tee joint at the bottom of the tank and also discharged through an
outlet in
the bottom of the tank to a service line. A drain cock in the bottom of the
tank for
feeding water to the service line is of little value other than as an
auxiliary supply line.
Discharging water through the bottom of the tank results in the discharge of
some of the
sand in the water into the drain line. Thus, mainly sand and solids that
originate in the
system's water supply are carried out of a tank to a faucet, sometimes
necessitating the
use of at least one filter. Sediments in the water source, some of which
accumulate in
the tank, are constantly flushed out of the tank passing through the service
line and
faucets connected thereto. However, most of the sediments from the water
source are
carried through the pump, the supply line, the pressure tank and the service
line
causing problems n the complete plumbing system.
Pressure tanks are available with or without interior bladders. The advantage
of
a bladder is that the tank cannot become water logged. In a pressure tank
without a
bladder, water and air are in direct contact and over time air is absorbed by
the water.
The tank becomes water logged when it contains insufficient air, and the pump
will go
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CA 02685803 2009-11-18
on and off more often than necessary, causing inconsistent pressure and
unnecessary
starting and stopping of the supply pump. Recharging of the tank becomes
necessary.
With a tank containing a bladder, there is no air-water contact, and
recharging should
never be necessary unless the bladder is ruptured.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a solution to the above-identified problems in
the
form of a pressure tank, which virtually eliminates the amount of sediment
discharged
from the tank into the service line.
According to one aspect the invention relates to a pressure tank assembly
including a tank having a side wall, a top wall and a bottom wall; an inlet in
the tank for
introducing water into the tank; a tubular ring in the tank midway between
said top and
bottom walls for receiving water from said inlet; a plurality of outlet
orifices in the bottom
of said ring for discharging water into the tank; a first outlet in the top
wall of the tank for
discharging water from the tank for use; an expansible bladder in the tank; a
valve in the
bladder extending out of said top wall for admitting or discharging air from
said bladder;
a second outlet in the bottom wall of the tank for discharging sediment from
the tank;
and a cage above said second outlet connected to a bottom end of said bladder
for
maintaining the bladder in a fixed position above the bottom wall and
permitting the
escape of water-borne sediment from the tank via said second outlet.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described below in greater detail with reference to the
accompanying drawings which illustrate preferred embodiments of the invention,
and
wherein:
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Figure 1 is a longitudinal sectional view of one embodiment of a pressure tank
assembly in accordance with the present invention.
Figure 2 is a cross-sectional view of the pressure tank assembly of Fig. 1
taken
generally along line 2-2 of Fig. 1;
Figure 3 is a longitudinal sectional view of a second embodiment of the
pressure
tank assembly;
Figure 4 is a cross-sectional view of the pressure tank assembly of Fig. 3
taken
generally along line 4-4 of Fig. 3; and,
Figure 5 is an exploded view of the bottom end of a bladder and a drain
assembly used in the pressure tank assemblies of Figs. 1 to 4.
When describing the second embodiment of the invention (Figs. 3 and 4),
wherever possible the same reference numerals have been used to identify
elements
similar to or the same as elements in the embodiment of Figs. 1 and 2.
With reference to Figs. 1 and 2, a pressure tank assembly in accordance with
the
present invention includes a hollow, cylindrical tank 1 with generally
hemispherical top
and bottom ends 2 and 3, respectively. The tank 1 is preferably formed of
fiberglass,
but can be produced using other materials. The tank 1 is usually mounted on a
stand 4
but can be otherwise supported in a use position.
A threaded opening 5 in the top end 2 of the tank 1 receives the externally
threaded bottom end of a manifold 6. A water inlet pipe 8 is connected to one
side of
the manifold 6 for introducing water via a passage 9 into the tank 1. Water
flowing
through the passage 9 enters an inlet tube 10, which extends along the inner
top end 2
and one side of the body 1 to a tubular ring 12 proximate the middle of the
tank.
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In a second embodiment of the invention (Figs. 3 and 4) the water enters the
tank 1 via an inlet pipe 13, a fitting 14 in the side of the tank and a tube
16 connected to
the ring 12. The ring 12 is supported in the body 1 by the tube 10 (Fig. 1) or
16 (Fig. 3)
and a chain or wire 17 extending between the bottom of the manifold 6 and a
side of the
ring 12 opposite the bottom end of the tube 10 (Fig. 1) on the inner end of
the tube 16
(Figs. 3 and 4). Water is discharged into the tank 1 via a plurality of holes
18 in the
bottom of the ring 12. Water for use in a dwelling or other building is
discharged from
the tank 1 via a second passage 19 in the manifold 6 and an outlet pipe 20.
An expansible bladder 22 is mounted in the center of the body 1. A valve 23 at
the top end 24 of the bladder 22 extends into a stepped hole 26 in the center
of the
manifold 6. The threaded stem of the valve 23 receives a nut 27 for tightening
a washer
28 carrying the valve on the bladder 23 against the bottom of the manifold 6.
As best shown in Fig. 5, the bottom end 30 of the bladder 22 carries a stem
31,
which extends downwardly through a cage 32 into a tubular post 33, which
extends
upwardly from the center of the open top end 35 of a drain pipe 36. The top
end 35 of
the pipe 36 is threaded for connecting the pipe to the tank 1. An O-ring 37
between an
annular flange 39 on the pipe 36 and the bottom of the tank 1 seals the pipe
with
respect to the tank. The cage 32 includes a disc-shaped top 40 and legs 41 for
supporting the top 40 above the bottom of the tank 1. Water and sediment 42
can
escape from the bottom of the tank 1 via gaps 43 between the legs 41.
In operation, the bladder 22 is inflated to the desired pressure, which is
preferably 5 - 20 psi. The tank 1 is filled with water via the inlet pipe 8 or
13, the tube 10
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or 16 and the ring 12. The pump can be operated until the pressure in the tank
1 is at a
sensible operating pressure such as 30 to 50 psi or lower or higher.
Because water entering the tank 1 is discharged downwardly from the ring 12,
solid particles in the water are started downwardly immediately upon exiting
the ring.
By locating the ring 12 midway between the top and bottom walls of the tank 1
and
including a plurality of holes in the ring, the water exiting the ring does
not disturb any
sediment in the bottom of the tank. The velocity of water in the annulus
between the
tank 1 and the bladder 22 is so much lower than the velocity of the water
entering the
tank via the inlet 8 or 13 and exiting at the outlet 20 that virtually no
solids can rise to
the top of the tank. When the pump is not operating and water is not being
withdrawn
from the tank 1, further settling of solids occurs. From time to time, a valve
(not shown)
in the drain pipe 36 is opened to remove sediment 42. Thus, solids in water
from the
tank 1 are substantially or completely removed before the water is discharged
from the
tank from the top thereof. Obviously, solids that remain suspended in water
will not
settle to the bottom of the tank.
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Dessin représentatif