Compact modular fluid storage and heating system

A modular fluid storage and heating system is provided which includes a plurality of different, interconnectable tank components of standardized dimensions such as fluid storage tanks, closure caps, and heater assemblies. Each of the tank components is sufficiently compact in size to pass through standard-sized corridors and doorways to permit assembly on site of a fluid storage and heating system configured specifically to the needs of a particular user. Because each of the tank components is of a standard size, fluid storage and heating systems may be constructed from standard-sized rather than from custom-sized components, thereby reducing considerably the expense and time associated with construction of such systems.

FIELD OF THE INVENTION 
This invention relates to fluid storage and heating tanks. 
BACKGROUND AND OBJECTS OF THE INVENTION 
A common problem faced by installers of fluid storage and heater tanks of 
large capacity is that limited means of access is provided to the room in 
which the fluid storage and heater tanks are to be installed. Typically, 
buildings and rooms have doors of standard width, commonly 32, 36, 48, or 
72 inches, and this limits the size, and thus the capacity, of the storage 
tanks which can be installed. 
It is, of course, usually possible to simply multiply the fluid heater and 
storage tank assemblies. Thus, one can obtain, for example, 100 gallon 
capacity by providing two complete 50 gallon hot water heaters. This 
solution is undesirable, of course, because then one has to have plural 
burners, which adds to the expense of the installation. See, e.g., U.S. 
Pat. Nos. 3,265,041 to McCarthy, Jr., and 4,023,558 to Lazaridis. Also, 
duplicative controls are required, which further adds to the cost of 
installation and maintenance. Moreover, the plumbing is unnecessarily 
complicated by such an arrangement. Therefore, there is a need for a fluid 
heater and storage tank assembly which is constructed in such a way so as 
to be essentially unlimited in fluid storage capacity, yet which has a 
maximum dimension so as to fit through standard doorways. In this way, 
essentially unlimited fluid storage capacity can be provided, even in 
rooms having standard size doors. To provide such a fluid heater and 
storage tank assembly is an object of the invention. 
It has also been the practice in the past to construct very large storage 
tanks and hot water heaters only upon receiving on order from a customer. 
Due to the low or unpredictable sales volume and large size of such tanks 
(e.g. 1,000 gallons), it was not feasible to maintain an inventory of any 
given size. Consequently, a customer needed to wait a considerable time 
for his order to be, in essence, custom-made. This practice, in turn, led 
to considerable inefficiencies in production and labor management, since 
the tanks were largely hand made, and a ready supply of labor was needed 
to fill each order. 
It is therefore a primary object of the present invention to eliminate 
altogether the above-described practice of manufacturing large storage 
tanks and hot water heaters on special order, while nevertheless enabling 
such tanks to be readily provided out of standard, pre-constructed 
components which can be maintained in inventory in large quantities and 
assembled in short order with a minimum of labor. 
Previous fluid storage structures are generally formed from single, 
massive, generally cylindrical storage tanks. By necessity, they need to 
be formed from very thick sturdy steel in order to withstand the 
tremendous pressures developed in the storage system. These pressures 
arise as a result of the quantity of fluid stored and the elevated 
temperatures at which the fluid is stored. Such thick steel is expensive 
and difficult to work with. 
Another object of the present invention is therefore to provide a modular 
fluid storage and heating system which is constructed from a plurality of 
relatively compact, lightweight, inexpensive components. 
SUMMARY OF THE INVENTION 
The present invention satisfies the above discussed needs of the art and 
objects of the invention by providing a modular fluid heating and storage 
system which is formed from a plurality of standardized components. The 
system of the invention comprises a base module, which comprises a tank 
connected to one or more heat sources for fluid heating, and which is 
provided with a number of tank mounting structures which provide both 
plumbing and support connection to any of a plurality of modular tank 
components. These tank components include additional base modules, 
auxiliary storage tanks, heater assemblies and end caps. Each of the tank 
components is constructed with a flange coupling for coupling with any of 
the storage tanks, thereby providing a fluid storage and heating system 
which may be readily and immediately assembled to meet the particular 
needs of the user. The individual components of standard size may be 
maintained in inventory so that very large, special order fluid storage or 
heating systems may be readily assembled in a short time with minimum 
labor. Each of the tank components is compact in size and may pass through 
conventional halls and doorways, thereby permitting assembly of the 
storage and heating system at the user's site. Due to the modular nature 
of the system, the heating and storage capacity of the system may be 
modified to meet the changing needs of the user without having to replace 
the entire system. Instead, one tank component, such as an end cap, may be 
replaced by another tank component, such as an auxiliary storage tank, to 
provide for increased storage capacity for the system. If additional 
heating is required, an additional heater assembly may be substituted for, 
e.g., an end cap. Therefore, the present invention provides a fluid 
storage and heating system of unprecedented flexibility in assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
I. First Embodiment 
FIG. 1 shows an embodiment of the invention in which a single additional 
storage tank 102 is attached to a base unit 101. The base unit 101 
comprises a heat source 103, shown as a fuel burner assembly. The fuel may 
be gas or oil; electric heaters are also within the invention. The heat 
source 103 is affixed to an end member 104, which contains a fluid inlet 
15 (see FIG. 7). This end member 104 is attached to a tank 105, which in 
turn is supported on conventional support members 106. The tank 102 is 
added to the base member 101 by a connection which is detailed below in 
FIG. 6. The connection between the base member 101 and the tank 102 
provides physical support as well as plumbing connections thereto. Water 
having been heated by burner assembly 103 is then stored in both tanks 101 
and 102 and withdrawn, preferably from the top of tank 102 as indicated at 
108; in this way, the hottest fluid, which rises due to convection, is 
always that which is withdrawn. 
The tanks 101 and 102 in this and the other embodiments may, for example, 
typically be provided in two sizes, which are, respectively, 27 inches in 
inside diameter, and 31 inches in diameter over the insulation, to conform 
to conventional doors which are typically 32 inches wide, or 39 inches in 
inside diameter, and 43 inches in diameter over the insulation, which may 
be used for areas where somewhat wider doors, e.g. walk-out basement doors 
and the like, are available. other diameters are of course within the 
invention, and can be selected on the basis of the particular application. 
The lengths of the tanks are arbitrary to provide for a wide range of 
available tank capacities. 
FIG. 2 shows a second embodiment of the invention having similar reference 
numerals where applicable. In this case, two tanks 102 are provided and 
the base tank 110 is accordingly lengthened to accommodate the two tanks 
102. 
FIGS. 3 and 4 show additional embodiments of the invention in which three 
and four additional vertical storage tanks 102 are provided. FIG. 4 also 
shows how dual burner units 103 can be provided as needed to heat the 
large volumes of fluid which can be stored in an assembly of this size. 
Again, the base storage tank 112 is sized in the embodiment of FIG. 3 to 
accommodate three vertical storage tanks 102, while in FIG. 4 the base 
storage tank 114 has four additional tanks 102 attached and hence is 
provided with four mating structures. 
It will be appreciated that the additional tanks 102 can be added as 
necessary, and that their capacities can be chosen as needed, due to the 
modular nature of this first embodiment of the system of the invention. 
Provided in tables I and II are examples of the variety of fluid storage 
configurations and capacities that are available in the tank system of the 
first embodiment of the present invention. 
Table I comprises three tables, labeled I(a)-(c). Across the top of each 
table appear the Roman numerals I-IV. These correspond to the embodiments 
of FIGS. 1-4, respectively. In the columns beneath them are the total 
storage capacities of the overall assemblies according to the embodiments 
of FIGS. 1-4. The capacities of the lower tanks are shown in the leftmost 
column, ranging from 125 gallons to 375 gallons. Thus, the 900 gallon 
total capacity under III in Table I(c) refers to an assembly of a lower 
tank 11 feet long having three 175 gallon upper tanks affixed thereto. The 
upper tanks in Tables I(a)-(c) are respectively of 125, 150 and 175 gallon 
capacity each. All of the lower tanks in Table I are of 27 inch vessel 
inside diameter and 31 inches insulated diameter, so as to pass through a 
standard 32 inch door. The numbers 3', 5', 8', 11' indicate the length of 
the overall assembly. 
TABLE II 
______________________________________ 
Lower Tank 
Capacity Length I II III IV 
______________________________________ 
(a) 250 Gal. Per Upper Tank 
250 3' 500 
525 7' 775 1025 
800 11' 1050 1300 1550 
1075 15' 1325 1575 1825 2075 
(b) 325 Gal. per Upper Tank 
250 3' 575 
525 7' 850 1175 
800 11' 1175 1500 1825 
1075 15' 1400 1725 2050 2375 
(c) 400 Gal. per Upper Tank 
250 3' 650 
525 7' 925 1325 
800 11' 1200 1600 2000 
1075 15' 1475 1875 2275 2675 
______________________________________ 
Table II comprises tables (a)-(c) and is generally similar to Table I 
except, in this case, the calculations are based on vessels of 39 inch 
inside diameter, which are 43 inches in diameter when insulated. In this 
case, the upper tanks added are of 250, 325 and 400 gallon capacity. It 
will be observed that the largest assembly shown, which is the embodiment 
of FIG. 4, is fifteen feet long and provides a total storage capacity of 
2,675 gallons. This amounts to a total of over 5,000,000 BTUs of stored 
hear energy, in a tank which still fits through a semi-standard 44 inch 
door. 
TABLE III 
______________________________________ 
Upper Tank Length 
Lower Tank 3' 5' 8' 11' 
Capacity/Length 
Capacity in Gallons 
______________________________________ 
125/ 3' 250 
175/ 5' 350 
275/ 8' 550 
375/11' 750 
______________________________________ 
In FIG. 5 is shown yet another embodiment of the invention. In this case, 
the added storage tank 120 has its axis generally horizontal, as does the 
base tank 116, and communicates therewith by two of the mating structures 
which are detailed in FIG. 6. This provides a storage assembly slightly 
lower in height yet having an extremely high capacity while still 
retaining the ability to fit through a standard door. The upper and lower 
tanks may be of the same or different sizes. Various possible tank 
configurations in accordance with this embodiment are set forth in Tables 
III and IV below. 
Table III shows the embodiment of FIG. 5 in a number of different lengths 
as listed. In this case, the lower and upper tanks are of similar 
capacity. The inside diameters of both vessels are 27 inches and the 
overall insulated diameters are 31 inches. 
TABLE IV 
______________________________________ 
Upper Tank Length 
Lower Tank 3' 7' 11' 15' 
Capacity/Length 
Capacity in Gallons 
______________________________________ 
250/ 3' 500 
525/ 7' 1050 
800/11' 1600 
1075/15' 2100 
______________________________________ 
Table IV is comparable, but shows capacities of the embodiment of FIG. 5 in 
which the vessels' inside diameters are 39 inches, and the vessels are 43 
inches in diameter overall when insulated. Here, the maximum value reached 
for a 15 foot long assembly of two tanks of 39 inch inside diameter is 
2,100 gallons. 
TABLE V 
______________________________________ 
Number of Tank Assemblies 
Length of Tank 1 2 3 
Assembly (inches) 
GALLON CAITY 
______________________________________ 
(a) Tanks Having an Internal Diameter of 23 Inches 
48 100 200 300 
78 150 300 450 
126 250 500 750 
(b) Tanks Having an Internal Diameter of 30 Inches 
48 150 300 450 
78 250 500 750 
126 400 800 1,200 
(c) Tanks Having an Internal Diameter of 42 Inches 
48 300 600 900 
78 500 1,000 1,500 
126 800 1,600 2,400 
______________________________________ 
FIG. 6 shows how the tanks 102 may be assembled to the base members, e.g., 
101. The base member 101 is provided with a flanged orifice 130, sized to 
mate with a similarly flanged orifice 132 on the upper tank. An O-ring 134 
is interposed between the two flanges. A flat gasket could also be used. 
The assembly is completed by a pair of clamps 140, 141 which are U-shaped 
in cross-section to clamp the two flanges together when the two clamps are 
held together by, e.g., bolts and nuts indicated generally at 136 and 137, 
respectively. The flanges could also be throughbolted to one another. In a 
preferred embodiment of this invention, the orifices are 18 inches in 
diameter. 
As shown, the orifices are quite large, which is desirable both to obtain 
efficient connection and to provide adequate support for the upper tanks. 
Because the orifice are large, fluid moves from one tank to another with 
low friction loss compared with conventional pipe couplings. The large 
orifices may therefore be said to enable direct connection of tanks. By 
"direct connection" it is meant that the tanks are either connected end to 
end to form a single larger tank element or tanks are connected via a low 
friction loss pipe or up raised portions extending from one or both tanks. 
Preferably these upraised portions can support another tank. 
The tanks together, because of the low friction loss direct connection, 
form substantially a single interior volume so that connected tanks act in 
essence as a single tank. 
II. Burner Assembly 
FIGS. 7 and 8 detail the structure of the water heater assembly which is 
preferably used according to invention. This assembly is the subject of 
Applicant's prior U.S. Pat. No. 4,465,024 and the following discussion 
thereof is taken from the '024 patent. Any additional disclosure from the 
'024 patent not expressly set forth below is incorporated herein by 
reference. Other heaters, including electric heaters, are within the scope 
of this invention. 
FIG. 7 shows a fluid heater which is used in the preferred embodiment of 
the present invention, designated generally as 31. The fluid heater 31 is 
attached to a storage tank end assembly 104, having a fluid tank 104. The 
interior 29 of tank end assembly 104 is empty in the disassembled state 
shown in FIG. 1, and, when assembled, forms a storage chamber for 
circulation of fluid. 
A combustion chamber assembly designated generally as 31 in FIG. 7 has a 
submersible portion which is adapted to be received within opening 19 in 
tank end assembly 104. The submersible portion of the assembly includes a 
submersible combustion chamber portion 33 comprising a cylindrical 
elongated member having an open end 35 and having an opposite closed end 
37. The combustion chamber assembly 31 also includes a mounting portion 
for detachably engaging the tank opening 19 for mounting the assembly 31 
within the tank. The mounting portion can conveniently comprise a tube 
mounting flange 39 located adjacent and connected to the combustion 
chamber open end 35 as shown in FIG. 7. The tube mounting flange 39 is a 
ring like body having an opening in the central part thereof which opening 
coincides with the opening in open end 35 of combustion chamber 33. Flange 
39 is securely affixed to chamber 33 as by welding or the like. 
As seen in FIG. 7, the combustion chamber assembly 31 also includes a 
plurality of curved fire tubes 41 each of which has an end 43 which 
communicates with combustion chamber 33 through closed end 37 (see FIG. 8) 
and which has an opposite end 45 which extends through the opening 19 when 
in place on tank end assembly 104. Each of curved tubes 41 is 
characterized in that at least a portion 47 of the length thereof is 
generally U-shaped. The configuration shown in FIG. 1 has a combustion 
chamber 33 which extends substantially the length of the curved fire tubes 
41 creating a long leg 49 running along the exterior of the combustion 
chamber 33 and separated by U-shaped portion 47 from a short leg 51 (see 
FIG. 8) which joins and extends through closed end 37. 
The ends 45 of curved tubes 41, as shown in FIG. 7, preferably extend to 
the tube mounting flange 39 and communicate through flange 39 by means of 
openings 53 with the tank exterior when the assembly 31 is received within 
the opening 19. The tube ends 45 are fixedly secured to flange 39 as by 
brazing the tube ends on the front and back sides of flange 39. Other 
assembly processes, such as rolling and welding, may also be employed. 
Although a small number of curved tubes 41 are shown in FIG. 1 for 
simplicity, a greater number of tubes and openings can be used in 
practice. Although steel can be used in constructing the curved tubes 41, 
other acceptable materials include copper, 90-10 copper-nickel alloy, 
titanium, and stainless steel. 
The combustion chamber assembly 31 can be mounted on the tank end assembly 
104 by providing a tank mounting flange 55 comprising a cylindrical ring 
which is fixedly connected to the tank exterior so as to circumscribe the 
opening 19 and to extend outwardly therefrom. The end 57 of tank mounting 
flange 55 can be provided with a plurality of threaded bores 59 which are 
suitably spaced to be alignable with matching bores 61 in tube flange 39, 
whereby the combustion chamber assembly 31 can be bolted to the tank 
mounting flange 55. In this way, the combustion chamber assembly 31 is 
removable from the tank end assembly 104 by detaching the tube mounting 
flange 39 and sliding the assembly out of the opening 19. Because of the 
arrangement of opening 19 in the vertical sidewall 21, the combustion 
chamber assembly 31 is mounted in a horizontal fashion with the 
longitudinal axis of the assembly 31 parallel to the plane of the support 
area 27. 
As shown in FIG. 7, a flue collector 63 is mounted on the tube mounting 
flange 39 and has an opening which communicates with the combustion 
chamber portion 33 and an annular chamber 67 which communicates with the 
fire tubes 41 by means of openings 53 in flange 39. A circumferential lip 
69 joins the base 71 of annular chamber 67 and is provided with a 
plurality of holes 73 which are alignable with bores 61 in flange 39 and 
threaded bores 59 in tank mounting flange 55 whereby flue collector 63 can 
be mounted on the exterior of the tank end assembly 104. Flue collector 63 
has a flue outlet 75 which communicates with the interior of annular 
chamber 67 and which can be connected to a flue pipe for carrying away 
waste gas as will be presently described. 
The opening 65 in flue collector 63 which communicates with chamber 33, as 
seen in FIG. 7, is provided in a circular partition 77 formed in the 
internal diameter 79 of the exterior portion of annular chamber 71. 
Partition 77 can be provided with a plurality of threaded lugs 81 which 
are fixed about the circumference of opening 65 and extend outwardly in 
normal relation thereto. A suitable heat source such as a burner means is 
mounted on the flue collector 63 and communicates with the flue collector 
opening 65 for supplying heat to tank 13. 
The heat source, as shown in FIGS. 7 and 8, can comprise a burner nozzle 83 
from a forced draft burner which has a circumferential ring 85 provided 
with a series of holes 87 which mate with and receive lugs 81 on partition 
77 for bolting the nozzle 83 onto the flue collector 63. In this way, the 
nozzle burner opening 89 can communicate with the combustion chamber 33 
whereby heat from the burner passes through the interior of the submerged 
combustion chamber 33 and through the fire tubes 41, thus further heating 
the water, into the annular chamber 67 of the flue collector 63, and out 
the flue outlet 75 to be exhausted. Preferably, the nozzle burner 83 is 
suitably constructed to work against a positive pressure. 
The operation of the present fluid heater will now be described in greater 
detail. The fluid heater is first assembled by mounting the fire tube 
assembly 31 within opening 19. The bores 61 in the fire tube flange 39 are 
aligned with the threaded bores 59 in tank flange 55 and the flue 
collector 63 is positioned over flange 39 with the flue outlet 75 directed 
upwardly with respect to the vertical side walls 21. Bolts through the 
holes 73 in circumferential lip 69 of flue collector 63 and fire tube 
flange 39 attach the combustion chambers assembly to the tank flange 55. 
The nozzle burner 83 is then bolted into place on partition 77 in flue 
collector 63 and water is introduced into the tank interior 29 through 
water inlet 15. In the configuration shown in FIG. 7, the burner is fixed 
to introduce hot gas into the combustion chamber 33 to provide a positive 
pressure within chamber 33, with the flue gasses passing out the curved 
fire tubes 41 and through the flue collector annular chamber 67 to the 
flue outlet 75 to be exhausted from the system. The burner 83 is switched 
off and on as needed to maintain the desired temperature level of the 
fluid contained in the tank in response to a conventional temperature 
control circuit of the type known in the art and familiar to those in the 
fluid heater industry. 
III. Modularity of Invention 
FIG. 9 shows another embodiment of the invention, corresponding most 
closely to FIG. 2. A base tank 200 is shown which may in essence comprise 
a section of cylindrical tubing having added thereto flanges 201, 202, and 
being formed by conventional metalworking processes to form upraised 
portions 203 and 204 to accept additional flanges 205 and 206. To these 
flanges may be added storage tanks 208 of any size desired, by way of 
additional flanges 209, or they simply may be capped by way of a cap 
member 210 and a flange 211. At the ends of the cylindrical base tank 200 
are added a heat source 212, which preferably is a burner as disclosed 
above in connection with FIGS. 7 and 8, but which may also comprise an 
electric heater of conventional type. Again, the connection is made by way 
of a flange 213. The other end of the tank may be capped as shown in FIG. 
9 by a cap member 215 and another flange 216, or may have added thereto 
another burner assembly comparable to item 212. The tank assembly is 
completed by feet 220, fluid outlet 225, preferably as shown at the top of 
the tank 208 to ensure withdrawal of the hottest fluid, and by fluid inlet 
226. 
IV. Second Embodiment 
FIGS. 10-15 depict individual modular components of a second preferred 
embodiment of the fluid storage and heating system of the present 
invention. A plurality of standard-sized modular components are provided 
to permit fabrication of a fluid storage system having virtually any 
desired storage capacity. Selection of appropriate components permits 
immediate custom manufacture of a fluid storage system from individual, 
preassembled elements, as will be described in greater detail below. 
FIG. 10 depicts a storage tank 200' having flanges 201' and 202' at 
opposite ends thereof. Flanges 201' and 202' provide for coupling with any 
of a plurality of modular tank components which are depicted in FIGS. 
10-15. 
FIG. 11 illustrates a storage tank 200" which is similar to the tank 
depicted in FIG. 10, with the exception of size. Tank 200" provides for 
greater storage capacity than does tank 200' by virtue of its greater 
length. The diameter of the two tanks are preferably the same to provide 
for standardization and to facilitate coupling of various modular tank 
components to be described in greater detail below. However, tanks of 
different cross-sectional width also fall within the practice of the 
present invention. Tank 200" includes flanges 201" and 202" for coupling 
with any of a plurality of other modular tank components. 
In FIG. 12 there is depicted a removable cap 210 having a flange 211 for 
coupling with one of the flanges 201', 202', 201" and 202" of the tanks 
200', 200" or any other correspondingly-sized coupling flange. Removable 
cap 210 is provided to seal an end or a side of a tank having a 
corresponding flange. Details of flange coupling are provided hereinbelow. 
FIG. 13 depicts a heater assembly 228. Heater assembly 228 comprises a 
heater 230 having a flange 234 for coupling with a corresponding flange of 
another modular tank member such as tank 200'or 200". The heater assembly 
228 provides for heating of the tank contents and seals an end or side of 
the tank in a manner similar to that performed by the cap 210. The heater 
230 may be fueled by natural gas, fuel oil, electricity, or any other 
conventional source of heat energy. 
A T-shaped modular tank 236 is depicted in FIG. 14. Tank 236 is open-ended 
and includes a pair of flanges 238 and 240 at each tank end. The sidewall 
242 of tank 236 includes an opening 244 from which extends coupling member 
246. Coupling member 246 comprises an outwardly extending shaft 248 and a 
flange 250 positioned adjacent the outer end of the shaft. The coupling 
member provides for fluid communication with another one of the modular 
tank components such as cap 210, heater assembly 228, or a coupling member 
of another tank. 
FIG. 15 depicts another tank structure 251 having a pair of coupling 
members 252, 254 extending outwardly from openings 256, 258 formed in 
opposite sides of tank sidewall 260. Coupling member 252 include an 
outwardly extending shaft 262 and a coupling flange 264 positioned 
adjacent the outer end thereof. Similarly, coupling member 254 includes an 
outwardly extending shaft 266 having a coupling flange positioned adjacent 
the outer end thereof. The coupling members 252, 254 provide for coupling 
with any of the various modular tank components, such as caps 210, heater 
assemblies 228, or tanks 200', 200", 236 or 251. Flanges 270 and 272 at 
opposite ends of the tank 251 also provide for coupling the tank to any of 
the variety of tank components. 
V. Modularity of the Second Embodiment 
The modularity of the second embodiment of the invention is illustrated in 
FIGS. 16-19, in which various combinations of the modular tank components 
of FIGS. 10-15 are depicted. Modularity arises in part from the provision 
of coupling flanges on each of the various individual modular tank 
components. By virtue of the modular design, each of the tank components 
may be assembled to one another immediately on order from a customer to 
form a fluid storage and heating system having a desired fluid capacity 
and configuration. The modular aspect of each of the tank components also 
provides considerable flexibility in incorporating various system 
modifications in response to changing needs which may occur over time. 
Also, the modular nature of each of the tank components allows for 
fabrication of a fluid storage and heating system on site from a plurality 
of tank components dimensioned to permit passage through conventional 
doorways and halls. 
With reference to FIG. 16, a first system component in the form of tank 
200' is positioned in axial alignment with tank 200". Flange 202' of tank 
200' is coupled to flange 201" of tank 200" to provide fluid communication 
between the two tanks. The manner of coupling will be described in greater 
detail hereinafter. Heater assembly 228 comprising heater 230 and 
connecting flange 234 is coupled to the other end of the tank 200' through 
corresponding connecting flanges 201' and 234. As discussed above, the 
heater may be powered by any conventional fuel, such as natural gas, 
electricity or fuel oil. The other end of the tank 200" is coupled through 
flange 202" to another auxiliary system component in the form of tank 
sealing means such as cap 210 through the cap flange 211. However, as will 
be discussed below, another auxiliary tank component such as heater 
assembly 228 or tank 200' or 200" may be substituted in place of the cap 
210 to provide for further expandability of the heating and storage system 
as the needs of the user require. For the purpose of illustration only, 
tank 200' preferably has a length of approximately 48 inches and an 
internal diameter of either 23, 30 or 42 inches. Tank 200" preferably has 
a length of approximately 78 inches and an internal diameter of either 23, 
30 or 42 inches. Modular tanks formed with these dimensions are well 
suited for passage through halls and standard sized doorways often-times 
present at the installation site. Fluid storage and heating systems of a 
variety of capacities may be constructed using, for example, the 48 inch 
and 78 inch long tanks as system building blocks. 
Fluid inlet 226 and heated fluid outlet 225 are also included as noted 
above to provide for fluid flow into and out of the storage and heating 
system. Preferably, fluid inlet 226 feeds into tank 200' adjacent heater 
assembly 228 to enhance fluid heating. 
FIG. 17 shows another arrangement for the modular fluid storage and heating 
system. Two T-shaped tanks 236 and 236a are coupled to one another at 
their respective coupling members 246. Each coupling member 246 includes a 
coupling flange 250 mounted at the end of a shaft 248. Shaft 248 extends 
substantially transversely and outwardly from the sidewall 242 a 
sufficient distance so that various tank components do not interfere with 
one another when they are included in the modular fluid storage and 
heating system. Flange 238 of the tank 236 is coupled to heater assembly 
228 through flange 234. Opposite tank flange 240 is coupled to tank 200" 
at flange 201". Flange 202" of tank 200" is coupled to cap 210 through cap 
flange 211. Alternatively, other auxiliary tank components having suitable 
coupling flanges may be substituted therefor. Thus, by virtue of the 
modularity of the system provided by the arrangement of coupling flanges, 
whereby any of a number of tank components may be joined to one another, 
fluid storage systems may be provided which are adaptable to the 
particular needs of the user, even as these needs change with time to 
require larger storage capacity or faster recovery times. Increased 
storage capacity is achieved simply by replacing, for example, a component 
such as cap 210 with any one or more of the tanks 200', 200", 236 or 251. 
Fluid inlet 226 feeds into tank 236 adjacent heater assembly 228 to 
provide fluid to be heated and stored in the tank. Heated fluid circulates 
to tanks 200" and 236a and exits therefrom through outlet 225. 
Support structure 274 may be provided to support the vertical arrangement 
of tanks 236 and 236a in order to maintain the tanks in the preferred 
vertical configuration. A vertical tank stacking arrangement is preferred 
because this arrangement conserves floor space and utilizes the inherent 
characteristic of a warm fluid to separate from a cooler fluid by rising 
therefrom, thereby permitting the burner assembly to warm primarily cooler 
fluid entering the tank 236 through the fluid inlet 226. Support structure 
274 includes a plurality of paired, opposed vertically extending beams 276 
coupled to one another at their respective feet 278 by transverse supports 
280. Each tank is connected to each beam 276 by a securing member such as 
a bolt 281 fixed to the exterior wall of the tank which extends through a 
correspondingly shaped channel 281a formed in the beam 276. Additional 
support is provided by the interconnected coupling member 246. 
FIG. 18 depicts yet another configuration for the modular fluid storage and 
heating assembly of the present invention. In this figure, tank 251 
includes a pair of opposed coupling members 252 and 254 for coupling with 
T-shaped tanks 236 and 236a, respectively. Heater assembly 228 is 
connected to the tank 251 through flanges 234 and 270 to provide heat to 
fluid contained within the tank assembly. Supplemental heater assemblies 
may also be provided, as will be discussed below. The opposite end of tank 
251 is coupled by flange 272 to tank 200" at flange 201". Flange 202" 
provides for coupling with another modular tank component, such as cap 210 
through flange 211, as shown in the drawing. 
Coupling member 252 provides for coupling of tank 251 at its upper end with 
T-shaped tank 236 through corresponding coupling member 246 and flanges 
264 and 250, respectively. Flange 264 is positioned at the end of shaft 
262, which extends radially outwardly from sidewall 260. Fluid 
communication between tanks 251 and 236 is thereby provided through 
corresponding coupling members 252 and 246 to provide for fluid storage 
capacity beyond that of tank 251 alone. The ends of tank 236 include 
coupling flanges 238 and 240 for coupling with further modular tank 
components. Coupling with caps 210 through cap flange 211 in the manner 
discussed above is depicted. However, it is understood that due to the 
modularity of the fluid storage system of the present invention, any of 
the tank components discussed above could be coupled to the ends of the 
tank 236 in place of caps 210. 
Coupling member 254 at the lower end of tank 251 provides for coupling with 
another tank, such as T-shaped tank 236a, through corresponding member 
246a in the manner discussed above. End flanges 238 and 240a provide for 
coupling to further tank components. Flange 238a is coupled to burner 
assembly 228a through flange 234a to provide for further heating of the 
fluid contents of the storage system. Flange 240a is coupled to tank 200"a 
at flange 201"a to further increase storage capacity of the system. 
Opposite flange 202"a of tank 200"a is coupled to cap 210, but may be 
coupled to another tank component such as a burner assembly 228 or another 
storage tank in accordance with the needs of the user. Fluid inlet 226 and 
heated fluid outlet 225 are provided in a conventional manner to permit 
fluid to circulate through the fluid storage system in the manner 
discussed above. Support structure 274 is provided to support each of the 
preferred vertical arrangements of storage tanks in the manner discussed 
above. 
VI. Flange Coupling 
With reference now to FIG. 19, another preferred arrangement is shown for 
coupling the various modular tank components to one another. Two tanks 236 
and 236a are shown having their respective coupling members 246 and 246a 
axially aligned for coupling with one another. Although coupling of the 
flanges of coupling members 246 and 246a is depicted, it is understood 
that the coupling principles are equally applicable to the coupling 
together of any of the flanges of the modular tank components. Flange 250 
is positioned at the end of shaft 248 which extends substantially 
transversely and outwardly from sidewall 242 of the tank 236. Similarly, 
flange 250a is positioned on the outer end of shaft 248a, which extends 
substantially transversely and outwardly from sidewall 242a of tank 236a. 
Shafts 248 and 248a may be welded to the respective tank sidewalls 242, 
242a or formed in any suitable manner. Preferably, flanges 250 and 250a 
are positioned adjacent the ends of corresponding shafts 248, 248a such 
that they are oriented substantially parallel to the tank to which they 
are connected. Typically, the flanges 250 and 250a are welded to their 
respective shafts, but other known securing arrangements may also be 
utilized. Gasket or sealing member 282 is interposed between opposed 
flanges 250 and 250a to provide a liquid-tight seal upon coupling of the 
flanges to one another. 
Each of the flanges 250 and 250a includes an arrangement of spaced 
apertures 284 extending transversely therethrough which may be aligned 
with corresponding apertures of the opposed flange. The gasket or sealing 
member 282 is provided with apertures 286 corresponding to the apertures 
284 formed in the flanges 250 and 250a. Flange coupling members, such as 
bolt members 288, extend axially through the paired apertures of the 
opposed flanges and the interposed gasket or sealing member to couple the 
flanges 250, 250a to one another and to provide for fluid communication 
between the tanks 236 and 236a. Nut members 290 extend over the respective 
ends of the bolt members 288 to secure the flange couplings provided 
thereby. 
VII. Advantages of the Modular Arrangement of Tank Components 
The modular nature of the system of the invention thus provides 
unprecedented flexibility in assembly of fluid storage and heating 
systems. In essence, a number of basic units, such as tanks 200', 200", 
236 and 251, heater assemblies 228, and caps 210 may be manufactured as 
inventory items; when a specific volume storage assembly is ordered, it is 
a straightforward matter to select the various parts needed from inventory 
to construct the desired tank storage or hot water heater assembly. 
A further advantage of the modular nature of the system is that much 
thinner steel may be used for constructing the components of the system. 
For example, whereas the thickness of the tank walls and caps in a typical 
pressurized 600-gallon conventional cylindrical storage or water heater or 
boiler tank structure is on the order of 5/8 inch and 3/4 inch, 
respectively, their corresponding thicknesses in the modular system of the 
present invention is only on the order of 3/16 inch and 1/4 inch, 
respectively. The modular tank components of the present invention are 
able to use thinner steel than prior art tank components because the 
modular tank components individually are of a much smaller size than the 
prior art components. Because prior art fluid storage structures were 
generally formed from single, massive storage tanks, they by necessity had 
to be formed from very thick, sturdy steel in order to withstand the 
tremendous pressures developed in the storage system. These pressures 
arise as a result of the quantity of fluid stored and the elevated 
temperatures at which the fluid is stored. Because the modular tank units 
of the present invention are considerably smaller in size than the prior 
art structures, yet can be assembled to produce a fluid storage facility 
of much greater capacity than heretofore available, thinner steel may be 
used in constructing the tanks. Therefore, besides providing a significant 
degree of flexibility in designing and constructing a fluid storage 
system, the present invention affords greatly reduced manufacturing costs 
due to the use of less material as well as the provision of 
mass-produceable, standardized components. 
In addition, the tanks may be constructed having standardized dimensions 
such as tank diameters and lengths to provide for mass rather than 
customized production of fluid storage and heating systems. The 
construction of components of this type is significant because it permits 
fabrication of extremely large storage systems from stock rather than from 
special order components, thereby greatly reducing the time and expense 
necessary to construct the storage system. For example, FIGS. 1-7, 9 and 
16-18 depict various tank arrangements for storage systems consistent with 
the practice of the present invention. As is clearly shown in these 
drawings, the modular nature of the couplings of the various tank 
components permits one to construct a fluid storage and heating system of 
extremely large, e.g., several thousand gallon fluid capacity, from 
components which are dimensioned to fit through a variety of standardized 
doorways. Because assembly of the fluid storage and heating system may 
occur at the installation site, one is not limited to a fluid storage 
system defined by the dimensions of the corridors and doorways of the 
facility in which the system is to be installed, as is the case in prior 
art storage tank systems. 
In the preferred embodiment, the tanks and attached tank components are 
depicted in a vertical orientation, with the fluid outlet at the top of 
the uppermost tanks in the system, so that convection will ensure that the 
hottest fluid is withdrawn. Side-by-side arrangement would also be 
possible if a large-enough plumbing connection were made between the 
tanks. Similarly, while cylindrical tanks are preferred for ease of 
manufacture, other shapes are possible. 
The advantages discussed above become more apparent when quantified and 
arranged in tabular form. For example, Table V is illustrative of the 
variety of tank configurations and capacities that are possible in fluid 
storage and heating systems in accordance with the embodiments depicted in 
FIGS. 16-19. The table is divided into three sections, labeled (a)-(c), 
wherein (a) represents fluid volume capacities of systems formed from 
tanks having an internal diameter of 23 inches; (b) represents fluid 
volume capacities of systems formed from tanks having an internal diameter 
of 30 inches; and (c) represents fluid volume capacities of systems formed 
from tanks having an internal diameter of 42 inches. In each of the 
tables, fluid volume capacities are provided for systems having from 1-3 
tank assemblies, wherein a tank assembly preferably represents one or two 
tanks having a longitudinal length of either 48, 78 or 126 inches. Single 
tanks of 48 or 78 inch length may be provided, whereas the 126 inch long 
assembly is formed from one 78 inch tank and one 48 inch tank arranged 
end-to-end. The designation "number of tank assemblies" represents the 
number of tank assemblies comprising the storage system. 
TABLE VI 
______________________________________ 
External Tank Minimum Door Frame 
Diameter (inches) 
Width (inches) 
______________________________________ 
23 30 
30 36 
42 48 
______________________________________ 
Table VI illustrates the relative tank/minimum door frame dimensions 
through which the three preferred tank widths of the present invention may 
pass in order to permit for construction of a modular fluid storage and 
heating system on the premises. Each of the preferred tanks of the 
diameters specified in the table is available in two preferred tank 
lengths, 48 inches and 72 inches. 
The minimum door frame widths listed in the table below provide for 2 
inches of clearance on each side of the tank in order to accommodate any 
tank maneuvering which may be necessary to pass the tank through the door 
frame. 
TABLE I 
______________________________________ 
Lower Tank 
Capacity Length I II III IV 
______________________________________ 
(a) 125 Gal. Per Upper Tank 
125 3' 250 
175 5' 300 425 
275 8' 400 525 650 
375 11' 500 625 750 875 
(b) 150 Gal. per Upper Tank 
125 3' 275 
175 5' 325 475 
275 8' 425 575 725 
375 11' 525 675 825 975 
(c) 175 Gal. per Upper Tank 
125 3' 300 
175 5' 350 525 
275 8' 450 625 800 
375 11' 550 725 900 1075 
______________________________________ 
The invention may be embodied in other specific forms without departing 
from the spirit or essential characteristics thereof. The embodiments 
described above are therefore to be considered in all respects as 
illustrative and not restrictive, the scope of the invention being 
indicated by the hereafter appended claims rather than by the foregoing 
description, and all changes which come within the meaning and range of 
equivalency of the claims are therefore intended to be embraced therein.