Dual pressure gas supply controller system for gas-burning apparatus

A dual pressure gas supply controller system is disclosed which provides apparatus and methods for supplying gas from a gas supply source to one or more gas-burning apparatus requiring two different gas pressure levels. According to the invention, a first gas pressure is supplied the gas-burning apparatus during a first time period, while a second lower gas pressure is supplied to the gas-burning apparatus during a second time period for the purpose of conserving gas. This is accomplished through the use of first and second gas pressure regulators coupled in parallel between the gas supply source and the gas-burning apparatus. A gas pressure control valve is utilized to stop the flow of gas from the first gas pressure regulator and enable the flow of gas from the second gas pressure regulator during the second time period. The gas pressure control valve can also be used to enable the flow of gas from the first gas pressure regulator and reduce the flow of gas from the second gas pressure regulator during the first time period. The gas pressure control valve can be controlled by an electrical circuit, such as a PLC to provide maximum automated performance.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to the field of gas supply controller 
systems. More particularly, this invention relates to apparatus and 
methods for supplying natural gas from a gas supply source to one or more 
gas-burning apparatus requiring two different gas pressure levels. 
2. Description of Related Art Including Information Disclosed Under 37 CFR 
1.97 and 1.98 
Many types of apparatus require natural gas to make them operational. Most 
of these devices, however, do not always require a constant optimal gas 
pressure to make them function as intended, especially during periods when 
the particular apparatus are intended to remain idle. Gas furnaces, for 
example, are not required to operate when the ambient temperature has 
reached a certain elevated level. Similarly, gas-operated lamps are not 
required during hours of daylight. To conserve gas, then, various 
mechanisms have been developed to automatically reduce the amount of gas 
flowing from the gas supply source to the gas-burning apparatus during 
such idle periods. 
The most common way to reduce the flow of gas to the apparatus is to couple 
it with some sort of switching mechanism, such as a thermostat or solar 
cell. This switching mechanism is typically used to engage a valve located 
between the gas supply source and the apparatus for the purpose of 
stopping or reducing the flow of gas to the apparatus at user-defined 
intervals. Often, a small bypass is also provided to supply minimally 
sufficient gas to support the pilot operations of the apparatus when the 
valve is engaged. 
The problem with the switching mechanisms previously developed is that they 
are either configured to operate with only one gas-burning apparatus or 
designed to interrupt or supply the flow of gas abruptly. In the case of 
gas lamps, for example, all previously invented gas lamp dimmer systems 
have been limited to control a single gas lamp, with severe limitations 
being placed upon the size of the lamp. However, these limitations 
unnecessarily force the consumer (who is attempting to save money by 
reducing the gas consumption of the lamps) to purchase, install, adjust, 
and maintain an equal number of specially fitted gas lamps and dimmers. 
Also, the performance of the gas lamp itself may be diminished because the 
life of the mantles is often reduced through the sudden fluctuations of 
gas pressures experienced whenever the gas flow to the lamp is abruptly 
enabled or stopped. The mechanisms devised for gas lamps also suffer from 
the fact that they have been designed in many cases to leave the gas lamps 
they control bright during all hours of darkness. The reason for this is 
that a typical mechanism for conserving gas uses a dimmer switch activated 
by a photocell. 
The present invention has several advantages over the switching mechanisms 
presently used for conserving gas. Specifically, the present invention 
places no limitation on the size or quantity of gas-burning apparatus 
employed. A plurality of gas lamps, for example, can be coupled to the 
present invention and will brighten and dim simultaneously to the same 
level of brightness with only a single adjustment made to the controller 
system described herein. Moreover, the adjustments made to the gas flow 
are gradual, as opposed to abrupt, making the change from one brightness 
level to another (in the case of gas lamps) gradual and much less 
detrimental to the life of the mantles. The present invention can also be 
programmed to supply gas (e.g., for brightening or dimming gas lamps) as 
often as needed during any 24-hour period. The ability to program the 
dimmer system allows the consumer to control the length of time gas lamps 
are bright and dim, thereby obviating the need for the gas lamps to remain 
bright during all hours of darkness. 
A fundamental feature of an embodiment of the present invention is that it 
controls the amount of gas pressure supplied to the gas-burning apparatus 
through the use of regulators that sense the pressure on the gas line 
feeding natural gas to the coupled gas-burning apparatus. This is a marked 
difference between all known previously invented switching mechanisms, 
which merely control the operation of the coupled apparatus by simply 
restricting the flow of gas. In contrast to the present invention, these 
switching mechanisms do not sense or maintain a constant pressure. 
The ability to regulate the gas pressure by sensing the pressure in the gas 
supply line enables the present invention to control a varying number of 
gas-burning apparatus without making adjustments to the dimmer system or 
changing components on the system. In order for the previously invented 
switching mechanisms to control multiple gas-burning apparatus, the size 
of the switching mechanism (e.g., the thermostat or dimmer) would have to 
be increased greatly and would have to be sized and configured for each 
application according to the number of apparatus to be controlled. This is 
a great disadvantage because the switching mechanism must be reconfigured 
anytime an apparatus is added to or removed from the system. This is not a 
problem with the present invention because it can easily adapt itself to 
increased or decreased loads. For the foregoing reasons, therefore, the 
present invention constitutes a significant advancement over the prior 
art. 
SUMMARY OF THE INVENTION 
The present invention is designed to effectively and efficiently control 
the usage of large numbers of gas-burning apparatus simultaneously. The 
dual pressure gas supply controller system described herein supplies gas 
from a gas supply source to at least one gas-burning apparatus in the form 
of first and second gas pressures and can be used with any apparatus 
requiring two different gas pressure levels. 
The first gas pressure is supplied to one or more gas-burning apparatus 
during a first time period to minimize the optimal amount of gas supplied 
to the apparatus. In contrast, the second lower gas pressure is supplied 
to the gas-burning apparatus during a second different time period to 
conserve gas. This is accomplished through the use of first and second gas 
pressure regulators coupled in parallel between the gas supply source and 
the gas-burning apparatus and through the use of a gas pressure control 
valve coupled to the first and second gas pressure regulators. When the 
gas pressure control valve is engaged to stop the gas flow from the first 
gas pressure regulator, the valve enables the flow of gas from the second 
gas pressure regulator only during the second different time period to 
provide the second lower gas pressure. When the gas pressure control valve 
is engaged to enable the flow of gas from the first gas pressure 
regulator, the valve reduces the flow of gas from the second gas pressure 
regulator only during the first time period to provide the first gas 
pressure. 
The method described herein of supplying a desired gas pressure to one or 
more gas-burning apparatus is comprised of the steps of supplying a first 
gas pressure with a first gas pressure regulator to the apparatus only 
during a first time period to minimize the optimal amount of gas supplied 
to the apparatus, supplying a second lower gas pressure with a second gas 
pressure regulator to the apparatus only during a second time period to 
conserve gas, and controlling the first and second gas pressures with a 
gas pressure control valve having open and closed positions coupled to the 
first and second gas pressure regulators to selectively stop the flow of 
gas from the first gas pressure regulator and enable the flow of gas from 
the second gas pressure regulator only during the second time period to 
provide the second lower gas pressure to the apparatus and conserve gas 
and to selectively enable the flow of gas from the first gas pressure 
regulator and reduce the flow of gas from the second gas pressure 
regulator only during the first time period to minimize the optimal amount 
of gas supplied to the apparatus. 
These and other aspects and advantages of the present invention will become 
better understood with reference to the following description, drawings, 
and appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
1. Controller System Overview 
FIG. 1 is a schematic diagram of a configuration upon which an embodiment 
of the present invention can be implemented. The dual pressure gas supply 
controller system 100 (referred to as controller system) includes a gas 
supply source 110 coupled to the upstream portions of a first gas pressure 
regulator 112 and a second gas pressure regulator 114. The downstream 
portion of the first gas pressure regulator 112 is further coupled in gas 
flow series to a gas pressure control valve 116, which is still further 
coupled to a gas supply outlet conduit 118 and the downstream portion of 
the second gas pressure regulator 114. In addition to being coupled to the 
downstream portion of the gas pressure control valve 116, the downstream 
portion of the second gas pressure regulator 114 is likewise coupled to 
the gas supply outlet conduit 118. The gas supply outlet conduit 118 is 
still further coupled to one or more gas-burning apparatus, such as gas 
lamps or other devices. 
The gas pressure control valve 116 operates to stop or enable the flow of 
gas from the downstream portion of the first gas pressure regulator 112 to 
the gas supply outlet conduit 118. Similarly, the gas pressure control 
valve 116 stops or enables the flow of gas from the downstream portion of 
the first gas pressure regulator 112 to the downstream portion of the 
second gas pressure regulator 114. Accordingly, then, the first gas 
pressure regulator 112 and the second gas pressure regulator 114 are 
aligned in parallel between the gas supply source 110 and one or more 
gas-burning apparatus coupled to controller system 100, with the flow of 
gas from the downstream portion of the first gas pressure regulator 112 to 
both the gas supply outlet conduit 118 and the downstream portion of the 
second gas pressure regulator 114 being determined by the operation of gas 
pressure control valve 116. 
In a preferred embodiment, the gas pressure control valve 116 is a solenoid 
valve that is opened or closed using a programmable logic controller (PLC) 
or other circuit 120 as described hereafter. In an alternative embodiment, 
the gas pressure control valve 116 is manually opened or closed to stop or 
enable the flow of gas from the downstream portion of the first gas 
pressure regulator 112. In yet another embodiment, the gas pressure 
control valve 116 is incorporated as an integral component of the 
downstream portion of the first gas pressure regulator 112 and is operated 
either manually or using a PLC circuit 120. 
The first gas pressure regulator 112 and the second gas pressure regulator 
114 provide, respectively, a first gas pressure and a second gas pressure 
through gas supply outlet conduit 118 to one or more gas-burning apparatus 
coupled to controller system 100. In a preferred embodiment, when the gas 
pressure control valve 116 is in the closed position (thus stopping the 
flow of gas from the first gas pressure regulator 112 ), only the second 
gas pressure from the second gas pressure regulator 114 is released 
through the gas supply outlet conduit 118 to one or more gas-burning 
apparatus coupled to controller system 100. Conversely, in the preferred 
embodiment, when the gas pressure control valve 116 is in the open 
position (thus enabling the flow of gas from the first gas pressure 
regulator 112), only the first gas pressure from the first gas pressure 
regulator 112 is released through the gas supply outlet conduit 118 to one 
or more gas-burning apparatus coupled to controller system 100. 
In the preferred embodiment, the first gas pressure supplied by the first 
gas pressure regulator 112 is that amount of gas pressure released though 
gas supply outlet conduit 118 which is minimally sufficient to provide 
optimal performance of the gas-burning apparatus to which controller 
system 100 is coupled. In the case of most two-mantle (double-inverted) 
gas lamps, for example, the first gas pressure supplied by the first gas 
pressure regulator 112 and released through gas supply outlet conduit 118 
is about three ounces. Of course, the most preferred first gas pressure 
supplied by the first gas pressure regulator 112 naturally depends upon 
the quantity and specific requirements of the gas-burning apparatus 
coupled to controller system 100. In no event, however, should the first 
gas pressure exceed that which would cause damage to components of the 
gas-burning apparatus (e.g., damage to gas lamp mantles). 
Conversely, the preferred second gas pressure supplied by the second gas 
pressure regulator 114 is that amount of gas pressure released through gas 
supply outlet conduit 118 which is sufficient to, at least, provide 
maximum gas conservation while the gas-burning apparatus coupled to 
controller system 100 are in reduced-gas-consumption mode. In the case of 
two-mantle (double-inverted) gas lamps, for example, the second gas 
pressure supplied by the second gas pressure regulator 114 should be the 
minimum amount of pressure needed to support the pilot operations of the 
gas lamps, which in most situations is about one ounce. As is the case 
with respect to the first gas pressure, the most preferred second gas 
pressure supplied by the second gas pressure regulator 114 naturally 
depends upon the quantity and specific requirements of the gas-burning 
apparatus coupled to controller system 100. In an alternative embodiment, 
the second gas pressure is any amount of gas pressure that is less than 
the first gas pressure. 
The adjustment of the first gas pressure regulator 112 and the second gas 
pressure regulator 114 depends upon the configuration of the specific 
make(s) and model(s) of regulators selected to implement controller system 
100. In this regard, the first gas pressure regulator 112 and the second 
gas pressure regulator 116 can be adjusted manually (e.g., by hand) or 
automatically using the PLC 120 to supply, respectively, the first and 
second gas pressures. In a preferred embodiment, however, the second gas 
pressure regulator 114 is adjusted automatically by sensing the gas back 
pressure caused by the presence of the first gas pressure (resulting from 
the opening of the gas pressure control valve 116) and reducing the second 
gas pressure to zero ounces. Alternatively, the second gas pressure is 
reduced to an amount greater than zero ounces but less than the first gas 
pressure to produce a gas pressure through gas supply outlet conduit 118. 
The first gas pressure should be adjusted downward to account for the 
coexistence of the second gas pressure and to ensure that the gas pressure 
released through gas supply outlet conduit 118 does not exceed that amount 
of gas pressure which is minimally sufficient to provide optimal 
performance of the gas-burning apparatus to which controller system 100 is 
coupled. 
The first gas pressure regulator 112 and second gas pressure regulator 114 
can be selected from literally thousands of different makes and models of 
regulators for reducing gas pressure that fit the specific type and 
quantity of gas-burning apparatus. The table below shows the capacity data 
of two readily available Fisher.RTM. brand regulators (Fisher Controls, 
Inc., Marshalltown, Iowa) that could easily be incorporated into the 
construction of controller system 100. 
__________________________________________________________________________ 
Maximum 
Maximum 
Maximum 
Maximum 
Maximum 
Number Of 
Number Of 
Number Of 
Number Of 
Number Of 
Inlet 
Outlet 
Capacity 
1000 BTU 
2-Mantle 
3-Mantle 
4-Mantle 
8-Mantle 
Type 
Pressure 
Pressure 
in SCFH 
Mantles 
Gas Lamps 
Gas Lamps 
Gas Lamps 
Gas Lamps 
__________________________________________________________________________ 
S102 
5 psig 
5" w.c. 
1,400 
1,400 700 487 350 175 
133L 
60 psig 
5" w.c. 
169,000 
169,000 
84,500 
56,333 
42,250 
21,125 
__________________________________________________________________________ 
Again, these are just two of many possible regulators that can be employed 
to fit a particular need. 
A preferred embodiment of controller system 100 configured for two-mantle 
(double-inverted) gas lamps, utilizes two Fisher-type S102, one-inch gas 
pressure regulators, piped in parallel, with a solenoid gas pressure 
control valve 116 in gas flow series with the first gas pressure regulator 
112 set at approximately five inches of water column pressure. The second 
gas pressure regulator 114 is set at approximately two inches of water 
column pressure. This configuration is adequate to supply first and second 
gas pressures for 1 to 700 two-mantle (double-inverted) natural gas street 
and yard lights and is ideally suited for most residential, 
"subdivision"-type situations. 
2. PLC Overview 
In FIG. 1, PLC 120 can also be coupled to a solenoid-operated gas pressure 
control valve 116 to implement an embodiment of the present invention. The 
PLC may be of a type such as a Sematic 37-200 manufactured by SEIMENS. PLC 
200, as is well known in the art, comprises a random access memory (RAM) 
or other dynamic storage device 214 (referred to as main memory), coupled 
to bus 210 for storing information and instructions to be executed by 
processor 212. Main memory 214 also may be used for storing temporary 
variables or other intermediate information during execution of 
instructions by processor 212. In FIG. 2, PLC 200 also comprises a read 
only memory (ROM) and/or other static storage device 216 coupled to bus 
210 for storing static information and instructions for processor 212. An 
output signal is generated at output device 220. A data storage device 
218, such as a magnetic disk and its corresponding disk drive, can be 
coupled to bus 210 for storing information and instructions. 
In one embodiment, PLC 200 is used to control the opening and closing of 
the gas pressure control valve 116 according to a set of user-defined 
instructions. According a preferred embodiment, this task is performed by 
PLC 200 in response to processor 212 executing sequences of instructions 
contained in main memory 214 or from another computer-readable medium, 
such as data storage device 218. Execution of the sequences of 
instructions contained in main memory 214 causes PLC 200 to emit or cease 
emitting an electrical charge to the solenoid unit coupled to the gas 
pressure control valve 116, thereby determining whether the gas pressure 
control valve 116 is open or closed. In alternative embodiments, 
hard-wired circuitry may be used in place of or in combination with 
software instructions to control the solenoid unit coupled to the gas 
pressure control valve 116. Thus, the PLC 120 is not limited to any 
specific combination of hardware circuitry and software. 
The user-defined instructions can vary widely from whether the input is 
received from a solar cell that indicates a period of darkness, whether a 
manual switch 228 is in the "on" position, whether the user desires the 
gas pressure control valve 116 to be opened or closed at predetermined 
times for predetermined time periods, to any combination thereof. For 
example, the user may want to supply gas lamps with the first gas pressure 
only between the hour of first darkness (controlled by input received from 
a solar cell 226) and 11:30 pm (controlled by the predetermined time). 
During the period between 11:30 pm and the next evening, therefore, the 
gas lamps will be supplied with the lower second gas pressure, thereby 
conserving gas. Using this combined configuration, the user would have to 
make fewer adjustments as the days get shorter and nights get longer 
during seasonal changes. 
As reflected in FIG. 1, PLC 120 is coupled to power supply 122. Power 
supply 122 provides the energy source needed to operate PLC 120 and can 
take many forms. In one embodiment, power supply 122 is a battery that 
supplies direct current electricity to PLC 120. In another embodiment, 
power supply 122 is an alternating current electrical energy source. In 
yet another embodiment, power supply 122 is a solar panel used for 
converting solar energy into electricity. In yet a further embodiment, 
power supply 122 is an electrical power generator coupled to gas supply 
source 110 via a conduit 124 for obtaining the natural gas fuel needed to 
operate the generator. Alternatively, the power generator can be operated 
using gasoline or a similar fossil-fuel energy source. 
EXAMPLE 
A prototype of controller system 100 has been constructed and field 
conditions were simulated. Standard gas pressure regulation and a standard 
gas control valve were used in the prototype. 
The corresponding structures, materials, acts, and equivalents of all means 
or step plus function elements in the claims below are intended to include 
any structure, material, or act for performing the function in combination 
with other claimed elements as specifically claimed.