US3730261A - Water heating system - Google Patents

Abstract

This invention relates to an industrial water heater of the socalled ''''instantaneous'''' type, featuring in functional combination; a single, compactly-sized, water storage tank; a heating tube bundle extending into the tank and enclosed within a novel water flow control shroud; the shroud being in communication with the discharge of a water circulating pump operating continuously to draw water from the tank and to circulate it through the shroud. The shroud is closed at its outer end and at its inner end except for a downwardly directed discharge opening. A circulating water temperature sensing bulb is disposed immediately adjacent to and in line with the flow of water from the shroud discharge, and is operable to regulate the rate of heat energy flow through the tube bundle so as to attain an improved water temperature change response, and constant maintenance of a desired storage water temperature condition. By virtue of the arrangement of the invention the heated water delivered from the shroud is directed downwardly into a water temperature ''''blending'''' section of the tank wherein it participates in a kinetic-convection temperature blending process before it rises to the upper section of the tank wherefrom it is immediately available for withdrawal through the service outlet from the tank. The invention also contemplates employment of an improved heat supply requirement anticipating arrangement, whereby an improved sensitivity of automatic operational control is achieved.

Description

United States Patent [191 Clark, Jr.

[ WATER HEATING SYSTEM John A. Clark, Jr., East Stroud sburg, Pa.

[75] Inventor:

[73] Assignee: The Patterson-Kelley Co., Inc., East Stroudsburg, Pa.

22 Filed: Apr. 26, 1971 [21] Appl.No.: 137,127

[52] US. Cl. ..l65/39, 165/108 [5l] 86Gb 1/019 [58] Field of Search ..165/39, 10%

[56] References Cited UNITED STATES PATENTS 3,364,986 1/1968 Morgan et al. 165/39 Primary Examiner-Charles Sukalo Attorney-.Brumbaugh, Graves, Donohue & Raymond ABSTRACT This invention relates to an industrial water heater oi" the so-called instantaneous type, featuring in functional combination; a single, compactly-sized, water storage tank; a heating tube bundle extending into the 1 May 1, 1973 tank and enclosed within a novel water flow control shroud; the shroud being in communication with the discharge of a water circulating pump operating continuously to draw water from the tank and to circulate it through the shroud. The shroud is closed at its outer end and at its inner end except for a downwardly directed discharge opening. A circulating water temperature sensing bulb is disposed immediately adjacent to and in line with the flow of water from the shroud discharge, and is operable to regulate the rate of heat energy flow through the tube bundle so as to attain an improved water temperature change response, and constant maintenance of a desired storage water temperature condition.

By virtue of the arrangement of the invention the heated water delivered from the shroud is directed downwardly into a water temperature blending section of the tank wherein it participates in a kineticconvection temperature blending process before it rises to the upper section of the tank wherefrom it is immediately available for withdrawal through the service outlet from the tank. The invention also contemplates employment of an improved heat supply requirement anticipating arrangement, whereby an improved sensitivity of automatic operational control is achieved.

3 Claims, 1 Drawing Figure DRAIN Patented May 1, 1973 DRAIN INVENTOR.

JOHN A CLARK, JR.

A TTORNEKS WATER HEATING SYSTEM THE DRAWING DETAILED DESCRIPTION OF THE INVENTION As illustrated herewith, the invention may be embodied by way of example in a water heating system ineluding a storage tank having a heated water outlet connection as indicated at 12 through the ceiling portion of the tank. The water heating component of the system is illustrated to comprise a bundle of reverse bent steam conducting tubes 14 carried by a tube sheet 16 which is affixed as indicated at 17 to the flange 18 of a tube shroud 20 which extends through a side wall opening of the tank 10. A bonnet as indicated at 22 is also affixed as indicated at 17 to the tube sheet 16, and is centrally partitioned as indicated at 24 so as to direct incoming steam from a conduit 26 into the upper legs of the tubes 14, and to divert the cooled steam condensates from the legs of the tubes through a conduit 28 into a suitable condensate strainer and trap system as indicated at 29, 30.

The tank 10 includes a water circulation outlet connection 32 which leads through a conduit system 34 to the intake of a continuously operating pump as indicated at 35; the discharge of the pump delivering water through a conduit system 36 into one end of the heat shroud 20 as indicated at 38. At its other end, interiorly of the tank 10, the shroud 20 is formed with a closed end wall portion 40 but is formed at itslower inner corner portion with a downwardly directed opening 42.

Thus, operation of the pump 35 provides a constant circulation of water from the lower level of the tank into the outer end of the heating shroud 20; thence through the shroud inheat exchange scrubbing relation against the tubes 14; and then exiting through the shroud opening 42 and thereby flowing downwardly therefrom into the temperature blending chamber por-- tion in the lower section of the tank. Portions of this blended heated water then move, notwithstanding the pump circulation process, upwardly into the top section of the tank 10 in response to convection current forces; whereby the blended heated water is constantly available for withdrawal through the outlet 12. The conventionally provided building recirculation conduit is shown at 46. Thus, upon withdrawals of heated water, replacement supplies of fresh water are automatically drawn into the system through a fresh water inlet connection, such as is shown in the drawing at 61.

As indicated at 50, a water temperature sensing bulb is mounted to extend into the path of water flow through the shroud opening 42, and is operatively cou pled as indicated at.52 to a steam flow regulating valve 54 which controls delivery of steam through conduit 26 to the tubes 14. Thus, the temperature of the water exiting from the shroud 20 is accurately sensed and em ployed to instantaneously regulate the steam supply to the heater tubes 14. A second temperature sensing bulb as indicated at 56 is provided in conjunction with a visual reading dial 58, whereby the temperature of the blended water supply available at the outlet l2is at all times evident. Thus, suitable adjustments of the system may be made, such as may be indicated in order to provide for delivery of water from the system as the desired temperature.

As illustrated at 60, a bypass conduit isconnected into the cold water inlet 61 for delivery of a small increment of fresh water inlets directly into a shroud 62 enclosing the temperature sensor bulb 50. The rate of flow of water through the bypass conduit is preferably regulated by means of a manually adjustable valve 65. Thus, it will be appreciated that a small percentage of any fresh water inlet to the circulation system will be transmitted directly to the sensing bulb 50. Therefore, assuming that the water being delivered to the heating unit suddenly assumes a drastic temperature change, the bypassed increment of circulating water will immediately signal the drastically changed temperature condition to the steam control sensor 50; thereby causing it to anticipate the requisite demand for a steam supply adjustment in order to compensate for the temperature variance existent in the system. It is to be understood, however, that instead of the manually ad I justable type valve as shown and described hereinabove for regulating the heat supply response to the rate of flow of water through the bypass conduit, any other suitable rate of flow responsive control device may be fluctuations, overheats, underheats, overrides, and/or the like are absorbed in the blending chamber section, thereby maintaining'the water temperature at the outlet connection substantially uniform or at least within tolerable variation limits. The invention also features a more rapid and sensitive automatic heat supply control response to water temperature fluctuations, due to the provision for relatively high velocity of water flow through the shroud outlet 42 and across the sensing bulb 50.- To that end, the cross-sectional flow area of the outlet opening 42 is reduced relative to that of the shroud 20 to provide increased water flow velocity through the opening. The sensing bulb 50 is positioned opposite the outlet opening 42 so as to lie in the region of increased flow velocity, as is illustrated in the drawing.

Furthermore, because the makeup cold water input connects into the system upstream of the water flow through the heating unit, the heat input control sensing bulb is not subject to wide temperature fluctuations such as would otherwise introduce override problems. On the other hand, upon proper regulation of the bypass control valve 65, sudden and excessive draws upon the system will be instantaneously and coincidentally compensated for by operation of the heat supply control system; thus avoiding the undesirable time lag problems which are inherent in conventional control systems. It is to be understood of course that whereas the specification herein refers to the use of steam as the heat supply-source, any other high temperature liquid or gas may be employed for heating the tubes 14; 'or alternatively, the heat energy supply arrangement may comprise a system of electric heating elements.

What is claimed is:

l. A water heating system of the instantaneous type comprising:

a compact water storage tank;

an immersion heater unit disposed to extend into the interior of said tank;

a shroud enclosing said heater unit and having a water inlet end and a water outlet end, the outlet end thereof being disposed interiorly of said tank, said shroud extending interiorly of said tank in spaced relation to the bottom wall of the tank so as generally to divide the tank into an upper hot water storage section and a lower water temperature blending section;

means for delivering cold water to the inlet end of said shroud;

means for withdrawing hot water from the upper section of said tank;

a conduit system having an intake end connected into the lower section of said tank and an outlet end connected into the water inlet end of said shroud;

a water circulating device in the line of said conduit system;

said shroud being closed at its outlet end with the exception of a reduced size heated water outlet opening through a bottom wall portion thereof directing heated water to flow therethrough at increased velocity downward into the lower section of said tank, whereby the heated water discharged from said shroud first blends with the water in the lower tank section and then rises to the upper tank section where it is available for withdrawal; and

a temperature sensing device positioned opposite said shroud outlet opening and in the region of increased water flow velocity from said outlet opening, said device being responsive to fluctuations in temperature of the water passing therethrough to regulate the operation of said heater unit.

2. A water heating system as set forth in claim 1 wherein said reduced size heated water outlet opening is provided through the interior bottom corner wall portion of said shroud. I

3. A water heating system as set forth in claim 1 further comprising bypass conduit means connecting into said cold water inlet means and discharging a small increment of the volume of water flowing through said inlet means directly against said temperature sensing device.

Claims (3)

1. A water heating system of the instantaneous type comprising: a compact water storage tank; an immersion heater unit disposed to extend into the interior of said tank; a shroud enclosing said heater unit and having a water inlet end and a water outlet end, the outlet end thereof being disposed interiorly of said tank, said shroud extending interiorly of said tank in spaced relation to the bottom wall of the tank so as generally to divide the tank into an upper hot water storage section and a lower water temperature blending section; means for delivering cold water to the inlet end of said shroud; means for withdrawing hot water from the upper section of said tank; a conduit system having an intake end connected into the lower section of said tank and an outlet end connected into the water inlet end of said shroud; a water circulating device in the line of said conduit system; said shroud being closed at its outlet end with the exception of a reduced size heated water outlet opening through a bottom wall portion thereof directing heated water to flow therethrough at increased velocity downward into the lower section of said tank, whereby the heated water discharged from said shroud first blends with the water in the lower tank section and then rises to the upper tank section where it is available for withdrawal; and a temperature sensing device positioned opposite said shroud outlet opening and in the region of increased water flow velocity from said outlet opening, said device being responsive to fluctuations in temperature of the water passing therethrough to regulate the operation of said heater unit.

2. A water heating system as set forth in claim 1 wherein said reduced size heated water outlet opening is provided through the interior bottom corner wall portion of said shroud.

3. A water heating system as set forth in claim 1 further comprising bypass conduit means connecting into said cold water inlet means and discharging a small increment of the volume of water flowing through said inlet means directly against said temperature sensing device.

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