Information
-
Patent Grant
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6354573
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Patent Number
6,354,573
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Date Filed
Monday, September 25, 200024 years ago
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Date Issued
Tuesday, March 12, 200222 years ago
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Inventors
-
-
Examiners
Agents
-
CPC
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US Classifications
Field of Search
US
- 261 29
- 261 35
- 261 361
- 261 77
- 261 128
- 261 130
- 261 131
- 261 141
- 261 1211
- 004 493
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International Classifications
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Abstract
A jet reactor pump as used to circulate heated water into a swimming pool at near sonic velocity to heat the swimming pool water.
Description
BACKGROUND AND SUMMARY OF THE INVENTION
Swimming pools are conventionally heated by introducing hot water (110° to 120° F.) into the pool at a velocity not exceeding 12 ft/sec to avoid large pressure losses. The heating system (very much like a water heater) heats a copper coil inside which the water travels, wasting 80 to 90% of the heat. Enormous losses occur when trying to heat a standard swimming pool of 22 ft.×15 ft×5 ft with 12,000 gal of water. During the heating process, heat is lost by evaporation from the pool surface to the environment at a rate proportional to the difference in temperature between the pool water and the atmosphere. The slower the water is heated, the greater the heat loss.
Heat transfer velocity is a function of
ΔV
2
=Relative Velocity of the two elements
φ=Flow rate of Heating Media
ΔT=Difference in temperature of the two elements
If superheated gas is introduced into the water at a very high velocity using a jet reactor pump, maximum heat transfer per unit time is possible since:
a) The gas can be introduced at a near sonic velocity (several orders of magnitude over 12 ft/sec)
b) Gas (air) can be heated to any temperature without the concern of vapor locking the system (for fabrication simplicity and safety, I recommend approximately 360° F. to 400° F.).
c) The gas/liquid flow efficiency of a jet reactor pump is well above 50% (volume to volume) which is several times a liquid/liquid pump. A liquid/liquid pump could be used, except that it has a maximum temperature limitation that gas/liquid does not.
d) A 4″ diameter pipe jet reactor pump could circulate all the water in a 12,000-gallon pool in two hours or less vs. 12 to 24 hours for present hot water systems.
e) The losses of heating the water pipe (convection—conduction), to heat the water (convection) and to inject in the pool water (conduction) is eliminated by simply heating the air inserted in the jet reactor that pumps the water as it is being heated.
f) As the water heats up, ΔT diminishes, reducing the heat transfer velocity (in the present systems)
T
water
≈120
20
T
start pool
≈50° F. T
finish pool
=70° F.
ΔT
start
=120−50=70° F.
ΔT
finish
=120−70=50° F.
with gas @ 360° F.
ΔT
start
=360−50=310° F.
ΔT
finish
=360−70=290° F.
This shows almost five times better temperature differential transfer rate at the start of heating, and almost six times better differential at the end of the cycle.
Preferably a compressor is used that is capable of delivering 50 to 75 ft
3
/min. of air @ 50 to 60 psig of pressure (this pressure assures gas sonic velocity in the jet reactor nozzles). Before inserting the air in the jet pump, a heater increases the air temperature to 360° F. to 400° F. The higher the gas temperature, the higher the thermodynamic efficiency of the heating cycle. The gas volume expansion at constant pressure will be:
This represents a water flow of approximately 42 ft
3
/
min
of water from the jet reactor pump or over 300
gal
/
min
which would allow the recirculation of a 12,000 gal pool in less than 40 minutes, unheard of in any water heater/water pump system.
DESCRIPTION OF THE DRAWINGS
The description refers to the accompanying drawings in which:
FIG. 1
is a schematic diagram, including a temperature feedback control system for reducing the heater operating temperature as the water in the pool reaches the desired temperature. The system will then maintain the desired temperature, only making up for the convection losses to the atmosphere.
FIG. 2
is an enlarged elevational view of an illustrative pump; and
FIG. 3
is a sectional view of the preferred pump.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, a compressor
10
compresses air received from a suitable source through a conduit
12
at 50 ft
3
/min at 50 psig. The compressed air then passes through a conduit
14
to a heater
16
at a rate of 80 c.f.m., which may be either electric or gas. The heater raises the temperature of the compressed gas to about 400° F. The heated gas passes through a conduit means
18
to a gas relief valve
20
and then to the intake of a jet reactor pump
22
. Pump
22
is disposed, for illustrative purposes, in a swimming pool
24
, which contains a body of water
26
having a water level
28
. Preferably, pump
22
has an inlet opening
30
that is three to six feet below water level
28
, a depth of “B”. The pump has an outlet opening
32
for discharging the mixture of water and air, preferably located a depth “A” about 1-3 feet below the water surface.
The general principles of such a jet reactor pump are described in my U.S. Pat. No. 6,039,917, issued Mar. 21, 2000 for “Jet Column Reactor Pump with Coaxial and/or Lateral Intake Opening”.
FIGS. 2 and 3
illustrate a pump useful for pumping and simultaneously introducing air into the body of water
26
. Pump
22
has a cylindrical inlet conduit
34
, a thin annular jet pump cover
36
, and an annular pump body
38
.
Cover
36
is mounted between the upper end of conduit
34
and pump body
38
, as viewed in FIG.
3
. Pump body
38
is welded to cover
36
, and has an inlet opening
40
for receiving an air-receiving conduit
46
. Inlet opening
40
is connected to an annular passage
48
that extends around the path of motion of the water generally shown in the direction of arrow
50
. Conduit
46
delivers air from compressor
10
. The pump materials may be of any suitable material that is compatible with the swimming pool water.
The jet pump body has three annularly spaced jet openings
52
, connected to passage
48
to the downstream face of the pump body. Openings
52
are disposed at an angle “C” of about 7.5° with respect to water motion
50
, to deliver the air in a conical path at sonic or near sonic velocity (whichever is best suited to the application) into the water flow. This arrangement transfers the air momentum to the water thereby increasing the pump efficiency. The compressed air is introduced into the water and expands to create a flow from inlet opening
30
to outlet opening
32
which in turn circulates the water in swimming pool
24
.
Assuming the pool water temperature at the start of the heating cycle is at temperature T
1
of 50° F., and it is desired to increase the temperature of the water to a temperature of T
2
of 70° F. The pump circulates the water in the pool while at the same time heating the pool water with the heated air.
A sensing conduit
53
measures the water temperature and feeds back a signal to water temperature feedback valve
54
that controls the temperature output of the heater temperature controller
56
. The heater temperature controller adjusts the heat output of heater
16
to a rate that accommodates the difference between the actual temperature of the water and the desired temperature.
The pool can be heated very quickly in 1-2 hours vs. 48-64 hours using present heating systems. After the pool is heated, the system is automatically reset for holding the injected air at 140°-160° F. in a sonic velocity transfer process to maintain the pre-selected temperature.
Preferably, no one is permitted to swim in the pool during the accelerated heating, for safety reasons. It is believed that the system using a low gas (air) flow and inexpensive equipment and operation costs will cost about 10%-15% of currently available commercial systems.
Claims
- 1. A method for heating a body of a liquid from a first lower temperature T1, to a second higher temperature T2, comprising the steps of:compressing a gas; heating the compressed gas to a third temperature T3, higher than a second higher temperature T2; introducing the compressed heated gas into an elongated heating conduit disposed in a body of a liquid having a lower temperature T1 such that the gas expands to induce a flow of the liquid in the heating conduit and raises the temperature of the flowing liquid in the heating conduit to a temperature greater than said second temperature T2, and then delivering the heated flowing liquid from the heating conduit into the body of the liquid to raise the temperature thereof toward temperature T2 at a heat transfer rate that is in accordance with the velocity of the heated liquid flowing from the heating conduit into the body of the liquid.
- 2. A method as defined in claim 1, including the step of using a jet reactor pump to circulate the liquid in the body of liquid.
- 3. A method as defined in claim 1, including the step of heating and compressing air.
- 4. Apparatus for heating and circulating a liquid in a container having an initial temperature T1, comprising:an elongated heating conduit having a liquid inlet opening disposed beneath the surface of a liquid in a container of the liquid, the liquid having a lower temperature T1; the heating conduit having a liquid outlet opening for discharging liquid received in the inlet opening along a path of motion, to a location beneath the surface of the liquid in the container; means for compressing a gas; means for heating the compressed gas to a temperature T3, which is greater than the temperature T1 of the liquid in the container; a plurality of gas-discharge nozzles in the heating conduit disposed around the path of motion of the liquid flowing through the elongated heating conduit; a gas delivery conduit connected to the heating conduit for delivering heated, compressed gas to the gas-discharge nozzles such that the heated gas induces a flow of liquid from the inlet opening to the outlet opening of the heating conduit and heats the induced liquid flowing through the heating conduit to a temperature greater than temperature T1; and the outlet opening of the elongated conduit being disposed to introduce the heated liquid flowing from the conduit into the body of liquid to heat the body of liquid to temperature T2 at a heat transfer rate that is in accordance with the velocity of the heated liquid flowing from the outlet opening of the heating conduit into the body of the liquid.
- 5. Apparatus as defined in claim 4, including a temperature feedback valve means for measuring the internal water temperature in the pool of water, and means connecting the feedback valve means to the heating means for controlling the heat input into the compressed air that accommodates the difference between the internal water temperature T1 and a desired water temperature T2.
- 6. Apparatus as defined in claim 5, in which the feedback valve is operative to signal the heating means to heat the water at an accelerated rate when the difference between T1 and T2 is greater than a desired ΔT, and at a standby rate when the temperature difference is relatively stable.
US Referenced Citations (12)
Foreign Referenced Citations (1)
Number |
Date |
Country |
201014 |
Mar 1907 |
DE |