US2315451A - Boiler - Google Patents

Description

March 30, 1943. e. w. PARKTON Filed May 18, 1942 'I'IIIIIIIIIII INVENTOR 3 George "(Parka/0n BY ATTORNEYS Patented Mar. 30, 1943 BOILER George W. Parkton, Dalton, Pa., assignor of onethird to Glen Brundage, Great Bend, Pa.

Application May 18, 1942, Serial No. 443,408

9 Claims. (Cl. 122122) My invention relates to boilers, and this application is a continuation in part of my copending application, Serial No. 347,403, filed July 25, 1940.

Boilers designed to make efiicient use of hot gases have been known and in general use for some time. Previous designs have merely provided additional boiler tubes and the water has been supplied in any convenient manner to the water chambers of the main boiler. No particular consideration seems to have been given to the manner of such supply of water, it apparently having previously been the thought that the utmost use had been put to the fuel gases exhausted from the boiler as soon as they had passed therefrom.

Various Water preheater systems have been devised to make use of the principles of counterflow and stratification in applying the hotter gases to the hotter water and in so conducting the gases that they exhaust from the preheater adjacent the water inlet to the same. These systems have attempted substantially to equalize preheater exhaust gas temperature and that of inlet water. designed in which the gases usually pass upwardly through one section of passages into a smoke-box and from the smoke-box usually downwardly through another set of passages, thence to a stack. The cold water inlet, which in a domestic heating boiler would be the condensate inlet, usually enters the boiler at the bottom adjacent the flue gas outlet. Such boilers, while serving to extract a great deal of heat from the flue gases, can never operate at maximum efficiency, for the reason that there is but a single body of water in the boiler and the colder condensate is permitted to, and is in fact forced to, mingle with the hottest water in the boiler; For that reason, the temperature of the products of combustion passing to the stack can never even approach the relatively low temperature at the condensate inlet.

The present invention proposes to overcome this diificulty by so regulating respective strata of fiue gases and boiler water that flue gases in their progress through the boiler system will meet successively colder layers of water and,

conversely, cold water meeting the coolest gases at first is progressively subjected to increasingly hot gases. The invention further proposes to aid this process by providing insulation between the part of the boiler heated by upwardly directed gases and that'part heated by downwardly directed gases, so that no heat interchange More specifically, boilers have been to speak of will be permitted therebetween, and the cool portion adjacent the water inlet will be substantially unafiected by that adjacent the fire-box water leg and vice versa.

It is an object of the invention to provide simple means for utilizing the utmost heat energy from the fuel heating a boiler in the production of steam.

It is another object of the invention to provide an improved type of boiler wherein the above indicated defects in or objections to many existing systems are substantially eliminated.

A further object of the invention contemplates the eflicient production of superheated steam.

Other objects and various features of the invention will be hereinafter pointed out or will become apparent to those skilled in the art from an examination of the accompanying drawing, in which- Fig. 1 is a front elevation in partial section of a boiler illustrating my invention;

Fig. 2 is a plan of the same with sections cut away to show construction of the interior;

Fig. 3 is an enlarged, fragmentary, vertical sectional view taken substantially in the plane of the line 3-3 of Fig. 1;

Fig. 4 is an enlarged, fragmentary, horizontal sectional view taken substantially in the plane of the line 4-4 of Fig. 1; and

Fig. 5 is a, fragmentary view of a modification.

In the drawing, a boiler system embodying my invention is seen to consist broadly of a unit embodying three component parts-a main boiler unit I, a steam box or superheater unit 2. and what in effect is a Water preheater unit 3.

The main boiler unit I comprises a fire-box 4, which may be such as to accommodate any fuelburning system. In the form shown, coal may be conveniently burned by automatic stoker or otherwise and the ash therefrom removed from the ash pit 5 through the door 6. The boilers are shown to be of the fire-tube type, with water I circulating around the heating tubes 8. A water leg 9 is preferably provided about the boiler walls and extends down below the tubes 8 to fill the chamber defined by walls [0 surrounding the fire-box 4. The water-level gauge "boiler. In the form shown, it is provided with fire or fuel gas tubes 12 similar to the tubes 8 of the main boiler. Cold water, which may be the condensate returning from the heating system,

chamber I! is defined by the walls 16 and serves as a passageway to conduct those flue gases which have passed through the main boiler tubes 8 over to the tubes I2 of the preheater unit. The outer or superheater chamber 24 is defined by the walls l6 and I8 and serves to subject the steam, which is admitted to it from both the main boiler and the preheater unit through connecting pipes l9 and respectively, to the relatively large heating surfaces of the wall 16, in contact with the hot main boiler flue gases. A steam outlet 2| conducts the steam to the house heating system.

The superheater unit, as shown, is preferably complete and separate from either of the boilers-that is, it merely rests on or is bolted down to the boilers, the steam connections l9 and 20 being provided externally so that the superheater unit may be easily removed for cleaning of boiler tubes 8 and I2 or for repairs. Conventional clean-out doors for the smoke-box may, of course, be provided.

In the modification shown in Fig. 5, the chamber of the jacketed smoke-box unit 2 is employed as a water heating chamber rather than solely as a steam chamber as in the form shown in Fig. l. The pipe I5 is connected to the chamber 2 at the water level therein and is connected to the first boiler unit preferably at a, lower level therein. The pipe I9 is connected to the boiler i in the steam space thereof and to the chamber 24 at a point above the water level in the latter. By partially filling the chamber 24 so as tocover the flat crown sheet l6 thereof with water, the capacity of the boiler is very greatly increased. If superheated steam is not desired, then the boiler arranged as in Fig. 5 would be the preferred form, since the capacity of such a boiler would be substantially greater than that shown in Fig. 1.

Operation of my invention is as follows:

Water is first introduced at the inlet 13 and supplied until the overflow connection [5 has permitted the proper level 23 to be attained in the main boiler, as may be viewed on gauge I 1. Heat generated in the firebox 4 is supplied to the main boiler water through the Water leg 9 and fire tubes 8. and the steam above the water level 23 is allowed to pass out of the main boiler and into the receiving or superheating chamber 24 through the conducting pipe i9. Hot flue gases leaving the main boiler tubes 8 are allowed to fill the smoke chamber ll, thus providing additional heat which is conducted through the walls 18 to the steam in chamber 24 where the superheating is effected prior to discharge of steam from the outlet 2|. The hot flue gases are next made to pass downward through the preheater tubes l2 and mak their exit through a suitable outlet or stack connection 25. A layer of insulating material 26 is preferably provided between the two boilers so as to minimize the degree of heat interchange between their respective walls.

It will be observed that the hottest fiue gases to contact the preheater tubes are at the top or entrance thereto. The heat furnished at I4 is sometimes sufiicient even to generate steam, provision for the collection of which is made in the connecting pipe 20, which conducts it to the superheater chamber 24 for subsequent mixture with the steam generated in the main boiler and for possible superheating. The water overflow pipe 15 enters the preheater tank at a point lower than the steam connection 20 so as to permit the passing off and collection of steam.

Of course, it will be understood that, if it is desired to make a connection between the preheater at the Water level therein and the main boiler above the water level therein, instead of as shown by the overflow pipe l5, then such a connection could also serve as a means for con ducting off steam formed in the preheater unit. Such a connection naturally would render unnecessary the steam pipe 20 between the preheater steam portion and the jacket portion of the smoke-box.

It will further be noted in accordance with my invention that, as the flue gases pass down the tubes l2, they cool progressively, at the same time heating progressively successive strata of water circulating about these tubes so that upon discharge the coolest gases are leaving the tubes at a point where the water about them is likewise the coolest encountered in the system; i. e., input water entering at the condensate return iii. In accordance with a natural phenomenon, warm water will tend to collect at the top of the preheater, and it is therefore always possible to pass off the hottest available preheater water to the main boiler through the overflow connection lb. The insulation 26 will reduce heat transfer from the main boiler and will assure that the coldest water available is always at the bottom of the preheater so that the utmost heat may be extracted from the flue gases before they pass out to the stack.

The action of the boiler shown in Fig. 5 is in all substantial respects the same as the boiler of Fig. 1, except that, generally speaking, the steam generated will not be superheated.

While the invention has been described in considerable detail, it is to be understood that many modifications and changes may be made within the scope of the invention as defined in the appended claims.

I claim:

1. A boiler, including a first boiler unit, a second boiler unit, and a third unit comprising a jacketed smoke-box, said first boiler unit having upwardly directed flue gas passages, said second boiler unit having downwardly directed flue gas passages, said third unit being positioned above the upper ends of said flue gas passages in both of said first and second units, a fluid connection between the upper part of said first boiler unit and said third unit, a fluid connection between the upper part of said second boiler unit and said third unit, and a fluid connection from one of said second and third units to the lower portion of said first boiler unit.

2. A boiler including a first boiler unit, a second boiler unit and a jacketed smoke-box unit, said first unit having upwardly directed flue gas passages, said second unit having downwardly directed flue gas passages, said jacketed smokebox unit being positioned to bridge the space above the tops of the flue gas passages of both said boiler units, a steam outlet from said jacketed unit, a steam outlet from the upper portion of said first unit and communicating with the jacket space of said third unit, a fluid connection between said second and third units, and a water connection from one of said second and third units at about the water level therein and communicating with said first unit.

3. In a boiler, a first boiler unit, a second boiler unit, said first boiler unit having upwardly directed gas passages, said second boiler unit having downwardly directed gas passages, a jacketed smoke-box unit bridging the tops of said gas passages of both said first and second boiler units, a steam communication from the steam space of said first boiler unit to the steam space of said jacketed unit, a fluid connection from the upper part of said second boiler unit to the jacket space of said jacketed unit, and a water connection from a point at the water line in said jacketed unit and communicating with said first boiler unit.

4. A boiler including a first boiler unit and a second boiler unit, said first boiler unit having upwardly directed flue gas passages, said second boiler having downwardly directed flue gas passages, a jacketed smoke-box unit bridging the space above the upper ends of the passages of both said boiler units, said jacketed smoke-box unit having a generally fiat crown sheet defining the top of the smoke-box portion of said unit, and fluid connections between each of said boiler units and said jacketed unit.

5. A boiler including a first boiler unit, a second boiler unit, said first boiler unit having upwardly directed gas passages, said second boiler unit having downwardly directed gas passages, a jacketed smoke-box unit bridging the space above the upper ends of the gas passages in both said boiler units, said smoke-box unit having a generally flat upper surface defining a crown sheet, a water connection between the upper part of said second boiler unit and said jacketed unit, a steam connection connecting the upper part of said first boiler unit and the upper part of said jacketed unit, and a water connection from about the water level above the crown sheet in said jacketed unit and communicating with said first boiler unit.

6. In a device of the character indicated, a fire-box, a boiler, a smoke chamber fixed above said boiler, a second boiler communicating with said smoke-box, said second boiler having downward passages for the gases from said smoke chamber, an outlet for the gases at the exit from said boiler, a water connection from the top of the second boiler to the bottom of the first mentioned boiler, a steam jacket about said smokebox, steam connecting means between said steam jacket and both of said boilers, and an outlet for steam from said jacket.

7. In a device of the character indicated, a fire-box, a main boiler having generally upwardly directed passages, a second boiler having generally downwardly directed passages and being thermally insulated from said main boiler and fire-box, a jacketed envelop bridging the tops of the passages of both the aforementioned boilers, steam conducting means between the steam space in each of said boilers and said jacket, and means for conducting water from substantially the top of said second boiler below the steam conducting means incorporated therewith, to substantially the bottom of said main boiler, for the purpose described.

8. In a device of the character indicated, a first boiler including a fire-box, a second boiler secured to said first boiler, said first boiler having upwardly directed gas passages and said second boiler having downwardly directed gas passages, a steam jacket defining a smoke-box bridging the upper ends of said gas passages in both said boilers, a pipe connection external to both said boilers and connecting the steam space of said first boiler to said steam jacket, and a pipe connection external to said boilers connecting the water space at the upper part of said second boiler to the water space at the bottom part of said first boiler.

9. In a device of the character indicated, a pair of generally rectangular boilers mounted side by side, insulating material interposed between said boilers, one of said boilers having upwardly directed gas passages, the other of said boilers having downwardly directed gas passages, a steam jacket defining a smoke-box bridging the upper ends of the gas passages of both said boilers, an external water connection connecting the upper part of the water space of said boiler having downwardly directed gas passages to the lower part of the water space of said boiler having upwardly directed gas passages, andexternal connections connecting the steam spaces of both said boilers with said steam jacket.

GEORGE W. PARKTON.

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