BOILER CONSTRUCTION
United States Patent 3554167
Covers a wet base multisectional boiler in which a substantially rectangular plate, preferably made of a refractory material, is inserted within the firebox of the boiler but adjacent to one of the sidewalls of the boiler. The plate is held within the boiler in a vertical or substantially vertical position. The insertion of the plate will reduce the amount of bubble formation within the sections on the sides or tubes adjacent to the plate. The flow of the heated water in each of the section adjacent to the plate will be modified to the extent that those sides or tubes of the sections adjacent to the plate will have water flowing downwardly to the base of the boiler and those sides or tubes of the sections remote from the plate will have water flowing upwardly into the common upper compartment.
US Patent References:
Boiler
Faber - August 1939 - 2168197


Inventors:
Martin, Allan E. (Tonawanda, NY)
Shirley, Edmund C. (New Albany, IN)
Application Number:
04/812241
Publication Date:
01/12/1971
Filing Date:
04/01/1969
View Patent Images:
Assignee:
American Standard Inc. (New York, NY)
Primary Class:
International Classes:
F24H1/32; F24H1/22; F22B23/00
Field of Search:
122/225,226,223,406
Primary Examiner:
Sprague, Kenneth W.
Claims:
We claim

1. A boiler comprising a plurality of U-shaped vertically arranged water-filled sections, a compartment partly filled with water and superimposed on said sections, said compartment being common to all of said sections and fluidically connected to all of the sections, a firebox bounded by the sidewalls and base wall of said sections and by said compartment, so that the firebox is surrounded by water within said sections and within said compartment, and a refractory plate positioned substantially vertically within said firebox and in physical contact only with one of the sidewalls of each of said sections.

2. A boiler according to claim 1 in which the refractory plate is replaced by a plurality of substantially vertical refractory plates coaligned with each other along only one of the sidewalls of each of said sections.

3. A boiler according to claim 1 having an upper nipple port adjacent to the compartment and located on one side of the boiler above said refractory plate.

4. A boiler comprising a plurality of closely adjacent U-shaped sections each of which is to be filled with water, a firebox space positioned within the sides of said sections so that heat generated therein will be freely conducted to the water within said sections, an upper compartment located above the firebox space and in communication with the open ends of all of the U-shaped sections, a lower nipple port common to all of the U-shaped sections and through which water is supplied to said U-shaped sections, an upper nipple port positioned above one side of the U-shaped sections and located adjacent to the upper end of said compartment, and a platelike member positioned substantially vertically within the firebox space but contacting only one of the walls of the U-shaped sections at a location beneath the upper nipple port, whereby heated water that enters the sidewalls of the U-shaped sections adjacent to the platelike member will travel downwardly while heated water entering the sidewalls of the U-shaped sections remote from said platelike member will travel upwardly to the compartment.

5. A boiler according to claim 4 in which the platelike member is composed of a plurality of platelike rectangular structures which are substantially colinear and extend throughout most of the depth of the boiler.

6. A boiler according to claim 5 in which all of the platelike structures are sloped with respect to the adjacent sidewalls of the U-shaped members so that the upper segment of the platelike structures will touch only one of said sidewalls and the lower segment of the platelike structures will be spaced from said sidewalls but in contact with the bases of the U-shaped members.

7. A boiler according to claim 6 in which the platelike structures are made of a material which will remain substantially uniform in its conducting properties throughout the range of temperatures encountered in operation of the boiler.

8. A wet base boiler comprising a plurality of closely adjacent U-shaped sections and an upper compartment common to all of said sections and fluidically in communication therewith, said sections and said compartment providing a common firing space in which a fuel may be fired for heating the water in said sections and said compartment, and means responsive to the heat generated in said firing space for causing the water within said sections on one side of said boiler to move substantially unidirectionally downwardly and for causing the water on the other side of said sections to move substantially unidirectionally upwardly, said means comprising a refractory plate positioned in said firing space adjacent to but one side of said boiler where the water is to move downwardly.

9. A wet base boiler according to claim 8 in which said means comprises a plurality of refractory plates which are aligned with each other and in contact with but one of the sidewalls of the sections in which the water is to move downwardly.

10. A wet base boiler according to claim 9 in which each refractory plate is notched so that it may be fixed in position in said firing space and is made of a substance which can withstand all temperatures encountered in the operation of the boiler without substantially altering its shape or its position.

11. A wet base boiler according to claim 10 in which each refractory plate is sloped with respect to the sidewalls of the sections with which it is in contact.

12. A wet base boiler according to claim 10 in which each refractory plate is made of a substance which is substantially nonconductive thermally.

Description:
This invention relates generally to boilers and, more particularly, to boilers of the wet base type.

It is one of the principle objects of this invention to improve wet base types of boilers and to increase their efficiency of operation.

In the so-called "wet base" boiler, the space within the several U-shaped sections of the boiler constitutes what is often known as the firebox of the boiler. In this particular type of boiler, the firing space or firebox typically is completely surrounded by water for improved heating conductivity. Each U-shaped section of a multisection boiler includes two vertical sides or two substantially vertical or somewhat inclined sides, which may be called sides A and B (i.e. the right and the left sides), and these two sides are tubular in shape and are joined to each other at the bottom by a third or base side which is also tubular and may be called side C of the section. Each such section is open ended at the top so that water flowing into and through the section will reach an upper compartment or section which may be called the compartment D. All of the several sections of the boiler supply their heated water to the upper compartment D which is common to all of the sections. Thus, the space within the several U-shaped sections, that is, the firebox, is completely encased in water and thereby insulated.

During the normal operation of a boiler embodying U-shaped sections of the kind above noted, the two vertical sides A and B of each of the sections are substantially equally heated by the burning gases present in the firebox. The temperature of the water within each of the two vertical sides becomes elevated during the heating process and produces bubbles within the water. The rate of production of bubbles, the size of the bubbles and the total volume of the bubbles increases with any increase in the rate of heat input within the U-shaped section. The heated water and the accompanying bubbles move upwardly in the two vertical sections to the upper compartment D where the bubbles, with the receipt of more heat, break the surface or upper barrier of the compartment D during the normal boiler operation. As these bubbles break the upper surface, they mix water with steam which has been accumulating in the upper compartment. Hence, the generated steam is reduced in quality in proportion to the relative volume of the bubbles breaking the surface of the upper compartment.

It has been observed that the upward movements of water within the two sides A and B of each boiler section are more or less equally directed upwardly to the upper compartment. Moreover, the bubbles usually become enlarged by joining or coalescing with each other. The bubble formation and the water streams within the sections introduce adverse effects. The level of the water in the upper compartment will be affected by the bubble paths and the water level will be found to be turbulent, that is, uneven, especially as the rate of bubble formation increases. An increased rate of generation of bubbles will materially increase the noise factor of the boiler. The internal stresses developed within the boiler will also be increased. Moreover, the efficiency of the boiler will be reduced. Furthermore, the quality of the steam is greatly reduced. The operating life of the boiler is consequently adversely affected by these developments. These conditions are undesirable and should be eliminated if not remedied.

In accordance with this invention, a plate of material, preferably a refractory material, such as firebrick, may be positioned within the firebox adjacent to one of the sides, for example, side A, of a section of the boiler or adjacent to adjoining sections of the boiler. The plate may be positioned vertically at the interface of the firebox and the side A of the boiler section, or it may be sloped from the vertical. When such a plate is inserted adjacent to a side or sides A of the boiler, the flow of fluid through the adjoining sections of the boiler will be very promptly changed. The water in the side A of the section--which is the side adjacent to the added or inserted plate--will be directed downwardly toward the bottom or base C of the adjoining section or sections, while the water flow through the opposite side or sides B of the boiler will be directed upwardly towards the common compartment D. The addition of the refractory plate adjacent to side A will yield a substantially unidirectional flow through the section or sections affected. In other words, the flow of water will be in a downward direction through the side A of each section even with temperature rises, then the flow will take place laterally or horizontally from side A to side B through the base C of each section, then upwardly through side B to the common compartment D. This unidirectional flow path will be maintained substantially throughout the operation of the boiler.

It has been observed that the substantially unidirectional flow path of water through the sections will be accompanied by a substantial reduction in the size and the number of the bubbles formed. Most of the bubbles will be produced in side B (which is the side physically removed from the inserted plate) while very few bubbles will be generated in the side A (which is adjacent to the inserted plate). It will likewise be observed that the level of the water in the upper compartment D will be and will remain substantially flat or even throughout the boiler operation. The result of all this will be that the steam produced by the boiler will be of improved quality. Thus, the addition of the refractory plate will serve to convert a relatively inefficient boiler into a highly efficient and readily salable generator of steam.

This invention will be better understood from more detailed description following when read in connection with the accompanying drawings in which FIG. 1 illustrates a front perspective of a wet base boiler from which the front end of the boiler has been removed and showing a plate positioned on the right side of the boiler; FIG. 2 illustrates a cross-sectional view of a multisection boiler when viewed along the centerline of the boiler and when viewed from the left side of the boiler; FIG. 3 illustrates a front view of an intermediate section of the boilers of FIGS. 1 and 2; and FIGS. 4a and 4b illustrate plan and end views of the refractory plate; FIG. 5 is a side elevational view of the boiler; and FIG. 6 illustrates a partial cross-sectional view of two adjacent sections of the boiler.

Referring to the drawings and especially referring to FIG. 2 of the drawings, there will be seen a four section boiler which comprises a front section 10, two center sections 20 and 30 and a back section 40. The inner walls of the several sections form a firebox 45. This boiler resembles a typical four-section pressure-fired boiler which has been marketed by the assignee of this application as the PF-A-3 boiler. Each intermediate section of the multisection boiler of FIG. 1 may correspond to the section designated 30 in FIG. 3. Each section such as 30 comprises a right side 42, a left side 44, a bottom or base side 46, and an upper compartment 48. The upper compartment 48 is common to all of the several sections of the boiler. The several sections of the boiler have in common two lower nipple ports 52 and 54, through either or both of which incoming water is normally fed to the boiler. The several sections are bound together by a nipple tie rod 60 in the usual way (see FIG. 5). The boiler includes a firing space, often called a firebox, which is designated 45 and it also includes an upper nipple port 80.

As is well known, an oil burner or gas burner of conventional configuration is supplied with oil or gas to be burned in the firebox 45 so as to simultaneously heat the water present in all of the several sections. Water is fed to the boiler through either or both of the lower nipple ports 52 or 54 so that water to be heated will be present in the vertical walls or tubes 42 and 44, the base wall or tube 46, and in most of the upper compartment 48. The water in the upper compartment normally rises to a level which is slightly above the bottom of the upper nipple port 80. In a conventional boiler (which does not employ a plate 70 of the kind shown in FIG. 1) the considerable heat generated in the firebox 45 causes the water to be heated substantially equally in the sidewalls or tubes 42 and 44, the heated water being accompanied by bubble formations. Both the heated water and the accompanying bubble formations are usually moved upwardly within the sidewalls or tubes 42 and 44 of all sections toward the upper common compartment 48. When the boiling point of the water is reached, steam will be generated in the upper compartment and then removed via a steam pipe from the upper nipple port 80 which is common to all of the several sections 10, 20, 30, 40, etc. The gaseous products of combustion within the firebox are discharged from the upper pipe which leads to the chimney.

When the plate 70 is inserted into the boiler in about the relative position shown in FIGS. 1 or 3--where the plate 70 is located on the same side as the upper nipple port 80--a distinct change in the pattern of water flow will be revealed in the operation of the boiler. Water present in the vertical wall 42 will be moved downwardly toward the base 46, with an accompanying reduction in the number and in the size of the bubbles generated. The downwardly driven water will then traverse the base or bottom wall 46 traveling from the right to the left, and thereafter moving upwardly along the left wall 44. The water flow along the left wall 44 will be directed continuously upwardly into the upper compartment 48. The upward flow will be rather smooth and substantially uniform.

It has been observed that, upon the introduction of the plate 70 into the burner firebox 45 adjacent to the water-filled wall 42, the level of the water in the upper compartment 48 will be relatively smooth and the bubble formation at the surface of the water will be reduced in volume at the side adjacent to the plate 70. The steam produced in the upper compartment 48 will travel through the upper nipple port 80 and supplied to the load by the boiler. The steam will be considerably improved in quality, that is, it will be substantially free of water droplets. The water circulation in each of the several sections adjacent to a plate such as 70 will be quite uniform, the water traveling only in a unidirectional path which is downward in each section adjacent to a plate 70 and upward in a section remote from a plate 70. The noise level will be reduced.

In a multisection boiler such as is shown in FIG. 1, two plates of refractory material, such as 70, would preferably be employed. One plate would be positioned adjacent to the sides of two of the sections and another plate positioned along the sides of the other two sections, but all such plates would be located on the same side, i.e., the right side of the boiler. If a six-section boiler is modified in accordance with this invention, three plates may be employed, one adjacent to each pair of adjoining sections. And so on.

The refractory plate 70, which is shown in FIGS. 1 and 3 as applied to a pressure-fired boiler, may have a length, i.e., its vertical dimension, of about 19.5 inches, a width of about 12 inches, and a thickness of about three-quarters of an inch. It may have two contoured notches 72 and 74. These notches would fit on the lugs at the base of the sections of the boiler so that the plates 70 can be maintained substantially immovable throughout the operation of the boiler.

It will be understood that each plate 70 may be positioned vertically or sloped somewhat from the vertical, as shown in FIG. 1. In FIG. 1 the base of the plate is spaced from the right sidewall 42 of the sections.

The addition of the plate 70 in accordance with this invention yields an improvement in the generated steam quality. The improvement could be observed through glass windows, which may be formed, for observation, adjacent to the upper nipple port 80. The improvement in the steam quality may also be demonstrated by measuring the reduction of wet particles in the steam. The plates 70 convert the wet base boiler into a considerably improved, efficient structure.

Although the invention has been shown and described as employing a plate 70 for a pair of boiler sections, a narrower plate may be employed to be individual to each boiler section. If desired, a longer plate may be used for more than two, perhaps for all, of the boiler sections. Furthermore, the plates 70, although shown and described as separate from the various boiler sections, may be manufactured as integral parts of the several sections.

Although the plates numbered 70 have been described as composed of refractory material, they may be made of any other material which would fully withstand the wide temperature range encountered in the operation of the boiler, under all of its conditions of operation.

While this invention has been shown and described in particular arrangements merely for the purpose of explanation and illustration, it will be understood that the invention may be set forth and embodied in many and widely varied organizations and applications, all within the scope of this invention.




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