US1166238A - Steam-boiler. - Google Patents

Description

' W. A. MOFFAT.

STEAM BOILER.

APPLICATION FILED JULY I2, I9I3.

Patented Dec. 28, 1915.

3 SHEETSSHEET l.

ambawto'o y/Z MZ W. A. IVIOFFAT.

STEAM BOILER.

APPLICATION FILED JULY l2, 19x3.

Patented Dec.- 28, 1915.

3 SHEETS-sugar 2.

W. A. MOFFAT.

STEAM BOILER.

APPUCATION FILED JULY 12. I913.

WALTER A. IVIOJFFAT, OF ERIE, PENNSYLVANIA.

STEAM-BOILER.

Specification of Letters Patent.

Patented Dec. 23, 1915.

Application filed July-12, 1913. Serial No. 778,767.

To all whom it may concern Be it known that I, WALTER A. MOFFAT, a citizen of the United States, residing at Erie, in the county of Erie and State of Pennsylvania, have invented new and useful Improvements in Steam-Boilers, of which the following is a specification.

This invention relates to improvements in steam boilers and has particular application to means for heating the feed water.

In carrying out the present invention, it is my purpose to provide a steam boiler wherein the water surfaces in contact with the heat of combustion will be divided in such manner as to produce an efficient and economical boiler and one wherein the feed water will be heated to any desired degree of temperature preparatory to entering the steam drums of the boiler.

It is also my purpose to provide a steam boiler wherein the feed water will be initially heated from the Waste heat of the boiler and then subjected to the heat of combustion in a separate fire box and heated to and beyond the temperature of .the saturated steam employed in the cylinders of the prime mover, the feed water after passing through this stage being delivered to a storage reservoir under the impulse of its own steam and thence fed to the main steam drums of the boiler in the same manner and evaporated in the usual way, thus enabling the ordinary heating surfaces of the boiler to more easily perform their rating, owing to the fact that the greatest heat of the fire box is not utilized to heat the feed water to the ordinary temperature of the steam.

l/Vith the above and other objects in view, the invention consists in the construction, combination and arrangement of parts hereinafter set forth in and falling within the scope of the claims.

lln the accompanying drawings; Figure 1 is a View in front elevation of a steam boiler constructed in accordance with the present invention, parts being shown in section. Fig. 2 is a vertical longitudinal sectional view taken through the boiler, parts being shown in elevation. Fig. 3 is a top plan view of the boiler, the connections between the combustion chambers and the stack being shown in section. Fig. 4 is a fragmentary perspective'view showing the drums and the connections between the same on an enlarged scale.

Referringnow to the accompanying drawings in detall, A designates a furnace composed of a plurality of independent oombustion chambers 1, three of such chambers being shown in the present instance. Arranged within each combustion chamber 1 1s a bank of water tubes 2 having the opposite ends thereof connected with vertlcal headers 3 disposed at the opposite ends of the combustion chamber. Sui-mounting the outer combustion chambers 1, 1 are the steam drums 4, 4 each having the opposite ends thereof connected with the headers 3, 3 wlthin the particular combustion chamber. Surmounting the central combustion chamber and disposed in a plane above the steam drums 4, 4 is a storage drum 5 havmg the opposite ends thereof resting upon cross boxes 6 seated upon the top wall of the combustion chamber and connected with the headers 3, 3 therein through the medium of suitable tubes or pipes. The storage drum 5 is preferably mounted above the drums 4 such a distance that the low water line of the storage drums corresponds with the high water line of the steam drums.

Surmounting the storage drum 5 is a feed water drum 7 having the opposite ends thereof resting upon and in open communication with cross boxes 8 disposed above thestorage drum and in communication with the boxes 6 through the medium of pipes or tubes 9. By means of this construction,

it will be seen that the contents of the steam drums are heated from the headers and bank of tubes within the respective combustion" chambers, while the bank of tubes and the headers within the central combustion chamber take care of the contents of the feed water drum. 7

A water supply pipe 10 is tapped into one end of the feed water drum 7 adjacent to the bottom thereof and is connected up with a feed Water heater heated from any and all sources of waste heat of the boiler. llhis supply pipe is provided with a controlling valve 11 and a check valve 12, the latter permitting the water to enter the feed water drum and preventing back flow. Leading out of one end of the feed Waterdrum ad jacent to the bottom thereof is a water tion between the drums and 7 may be readily established and cut off. Pipes 15,

each has the lower end connected with one vided with a manually operable controlling valve 17 whereby communication between the water spaces of the storage and steam drums may be conveniently established and cut off. Each pipe 15 is equipped with a check valve 18 whereby the water may fiow from-the storage drum to the steam drums and back flow eliminated. A steam pipe 19 has one end thereof connected to one end of the feed water drum adjacent to the top thereof and the opposite end connected with the steam space of feed water heater so that the pressure within the feed water drum and feed water heater may be equalized, such steam pipe being provided with a manually operable controlling valve 20. a

In operation, the valve 14 in the pipe 13 is shut off so that communication between the feed water drum and the storage drum is cut off, while the valves 11 and 20 in the water supply pipe 10 and equalizing steam pipe 19 are opened and the water from the feed water heater permitted to flow into the drum 7, the valve 20 being closed succeeding the filling of the drum 7. When the water in the drum 7 has been sufliciently heated, incident to circulating through the headers and banks-of water tubes in the particular combustion chamber, the valve 14: is opened so that the Water within the feed water drum will be blown down into the s'orage drum 5. The feed water drum is preferably provided with a safety valve 21, while the steam drums are provided with similar valves 22,

the storage drum being also equipped with a. similar safety valve 23. The valve 21 of the feed water drum responds only when the pressure within such drum is greater than that required to open the valves of the steam drums. When necessary, the pressure between the steam drums and the storage drum is equalized so that the'water within the storage drum will gravitate into the water space of the steam drums by way of the pipes 16 and 15 and maintain the water level in the steam drums to compensate for evaporation. For this purpose, I employ pipes 24, 24 each having one end tapped into the steam space of one of the steam drums, while the free ends of such pipes are interconnected .by means of a horizontal pipe section'25 tappedinto the steam space of the ,storage drum, the pipes 24, 24 being provided with manually operable controlling valves 26 whereby the communication between the steam spaces of the steam drums and the storage drum for equalizing the pressure may be readily controlled. The numeral 27 designates a steam equalizing pipe having one end connected with the steam space of the storage drum and the opposite end tapped on to the steam pipe 19 immediately adjacent to the connection between the latter and the feed water drum so that the pressure within the drums 5 and 7 may be equalized, the pipe 27 being pro vided with a controlling valve 28.

Under normal conditions, the pressure in the feed water drum is sufficient to blow the heated water into the storage drum by way of the pipe 13 connecting said drums when the valve 14 is open, while the pressure in the storage drum, being greater than that in the steam drums blows the water from the storage drum into the steam drums. In some instances, the storage drum may be filled to its capacity and in this case, the feed water drum 7 is placed in open communication with the steam spaces of the steam drums thus making the feed water drum, in effect, a part of the main boiler and permitting the steam to-flow from the feed water drum into the steam drums. For this purpose pipes 29, 29 each has the lower end thereof tapped into the steam space of one of the steam drums while the free extremities of such pipes are connected through the medium of a horizontal pipe section 30, the latter being connected with the steam pipe 19 at the point of connection between the last-named pipe and the pipe 27. The pipes 29 are equipped with manually operable controlling valves 31 whereby communication between the steam spaces of the steam drums and the feed water drum may be established and cut off. Subsequent to the water flowing into the storage drum from the feed water drum, as previously described, the valves 26, 26 in the pipes 24;, 24 are opened so that the steam spaces of the drums 4, 4 and the storage drum will be in communication, thereby permitting the water within the storage drum to continuously gravitate into the water spaces of the steam drums by way of the pipes 16 and 15, and the steam to flow through the pipes 24:, 24, the valve 17, of course, being open, the weight of the water opening the check valves 18. Thus, it will be seen that the water and steam will flow continuously into the steam drums as the steam is consumed. In the event of the feed water drum being filled to its capacity and steam generating in the feed water drum, the valves 31, 31 in the pipes 29, 29 are opened so that the steam within the steam space of the feed water drum will flow into the steam spaces of the steam drums, incident to the safety valve of the feed water drum responding to a higher pressure than that required to open the similar valves of the steam drums. It

will, of course, be understood that each drum is equipped with the usual Water glass and pressure gage and blow-off valves.

The numeral 32 designates a smoke stack common to the combustion chambers and each combustion chamber is provided with a damper whereby communication between the same and. the smoke stack may be controlled. In order to economize in fuel and heat the air previous to the latter passing between the bars of the grates in the combustion chambers and through the fuel on such grates, I employ a conduit 33 disposed concentrically of the smoke stack 32 and spaced apart therefrom a suitable distance. Leading from the conduit 33 at diametrically opposite points are air conveying pipes 34 disposed at the opposite sides of the furnace structure A and having the free ends thereof connected with an air pipe 35 passed transversely through the ash pits of the combustion chambers and provided with suitable discharge openings below the grates so that the air may be.discharged through the latter. From this construction, it will be seen that when all the entrances to the ash pits and fire boxes are closed, the column of.

. connection with the, accompanying drawings,

the construction, mode of operation and manner of employing my invention will be readily apparent. It will be seen that I have provided a steam boiler wherein all the heating surfaces are converted into boiling areas thereby increasing the efficiency and capacity of the boiler and centralizing the scaledeposits, while the feed water is thoroughly and efliciently heated preparatory to entering the steam drums so that expansion and contraction of the latter, incident to cold feed water is largely avoided.

While I have herein shown and described one preferred form of my invention by way of illustration, I wish it to be understood 7 that I do not limit or confine myself to the precise details of construction herein described and delineated, as modification and variation may be made Within the scope of the claims without departing from the spirit of the invention.

I claim:

1. In a steam boiler, a steam drum, :1 storage drum designed to maintain a greater pressure than said steam drum and located at a greater altitude than said steam drum,

WEI:

a feed water heating drum disposed above said storage drum and designed to maintain a pressure greater than that of said storage drum, connections between said feed water heating drum and storage drum whereby the water may be delivered to said storage drum succeeding the preliminary heating thereof and under the pressure of said feed water heating drum, and connections between said storage drum and steam drum whereby the water will be fed from said storage drum to said steam drum under the pressure in said storage drum.

2. In a steam boiler, a steam drum, a storage drum designed to maintain a greater pressure than said steam drum and located at a greater altitude thansaid steam drum, a feed water heating drum disposed above said storage drum and designed to maintain a pressure greater than that of said storage drum, connections between said feed water heating drum and storage drum whereby the water may be delivered to said storage drum succeeding the preliminary heating thereof and under the pressure of said feed water heating drum, connections "between said storage drum and steam drum whereby the water will be fed from said storage drum to said steam drum under the pressure in said storage drum, and means for connecting the upper portions of said feed water drum and storage drum to equalize the pressures therein.

3. In a steam boiler, a steam drum, a storage drum designed to maintain a greater pressure than said steam drum and located at a greater altitude than said steam drum, a feed water heating drum disposed above said storage drum and designed to maintain a pressure greater than that of said storage drum, connections between said feed water heating drum and storage drum whereby the water may be delivered to said storage drum succeeding the preliminary heating thereof and under the pressure of said feed water heating drum, connections between said storage drum and steam drum .whereby the water will be fed from said storage drum to said steam drum under the pressure in said storage drum, means for connecting the upper portions of said feed water drum and storage drum to equalize the pressures therein, and means .for connecting the steam space of said steam drum with the upper portion of said storage drum to' equalize the pressures therein.

4. In a steam boiler, a steam drum, a storage drum designed to maintain a greater pressure than said steam drum and located at a greater altitude than said steam drum, a feed water heating drum disposed above said storage drum and designed-to maintain a pressure greater than that of said storage drum, connections between said feed water heating drum and storage drum whereby the water may be delivered to said storage drum succeeding the preliminary heating thereof and under the pressure of said feed water heating drum, connections between said storage drum and steam drum whereby the water will be fed from said storage drum to said steam drum under the pressure in said storage drum,v means for connecting the upper portions of. said feed water drum and storage drum to equalize the pressures therein, means for connecting the steam said storage drum and designed to maintain a pressure greater than that of said storage drum, connections between said feed water heating drum and storage drum whereby the water may be delivered to said storage drum succeeding the preliminary heating thereof heating drum, connections between said and under the pressure of said feed water storage drum and steam drum whereby the water will be fed from said storage drum to said steam drum under the pressure in said storage drum, and means for placing the upper portions of all of said drums in communication with one another to equalize the pressures therein when conditions warrant.

In testimony whereof I afiix my signature in presence of two witnesses.

WALTER A. MOFFAT.

Witnesses:

E. 'EoMoNs'roN, Jr., JOHN J. MCCARTHY.

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