US2037018A - Boiler - Google Patents

Description

W 19363, 5 HALL mamas BOILER Filed July 18 1934 2 Sheets-Sheet l INVENTOR.

MORA S. HALL ATTORNEY.

A rrifi 14,1936. M. s. HALL wsmm BOILER Filgd July 18, 1934 2 Sheets-Sheet 2 INVENTOR.

MORA S. HA-LL ATTORNEY.

Patented Apr. 14, 1936 UNITED STATES BOILER Mora S. Hall, Baltimore, Md., assignorto May Oil Burner Corporation, a corporation of Maryland Application July 18, 1934, Serial No. 735,875

'1 Claims.

This application is a continuation-in-part of my application Serial No. 575,616 filed November 1'7, 193 1.

This invention relates to an apparatus for increasing the heat absorption capacity of heating devices; more particularly low pressure boilers employed for house heating.

This invention also has special application to the increase in heat-transfer efficiency of a boiler previously operated as a solid fuel burning device and converted to a boiler operated by burning fluid fuel.

Boilers employing solid fuel are mostly served with substantially continuous fire applied rather gradually and steadily, while in oil burner use firing is generally rapid and intermittent. In the latter case, the period during which the heattransfer may take place is very much shorter than in the former case, and it has also been found that the fuel gases carry out of the chimney very large amounts of heat, thereby reducing the heating efiiciency considerably when a change is made from solid fuel to oil burning. In order to take care of this condition, a more rapid and greater exchange of heat from the furnace gases to the water in the water compartment has been found most desirable. Owing to the great variety in boiler construction it has been found that structural changes, suitable for some types of boiler, for promoting a more rapid and greater exchange of heat from the furnace gases to the water in the water compartment, were not satisfactory for other types of boilers. A suitable means practically and universally suited for improving the heat-transfer in the various kinds of boilers heretofore employed with solid fuel so as to give satisfactory heat-transfer when these boilers are converted into oil burner heaters has been much sought and greatly desired.

Among the objects of this invention is to provide means, suitable for oil burning, low pressure heating devices, including heating devices of the kind originally constructed for oil burner use as well as those originally constructed for use with solid fuel and subsequently converted for oil burner use, for increasing the heat absorption capacity of the device and effecting a more rapid and greater exchange of heat from the furnace gases to the water in the water compartment of the heater.

More specifically, it is an object of this inventionto provide means readily attachable at any and all parts of the heat-transfer wall between the water compartment and the heating gas compartment of the boiler for increasing and accelerating the heat-transfer from the heating gas compartment to the water compartment at any part of the wall separating these compartments. The location of this means may also be varied to meet particular needs for changing the quantity and/or rate of heat-transfer at any and all parts of the heat-transfer wall.

Other, further, and more specific objects of this invention will become readily apparent to persons skilled in the art from a consideration of the following description when taken in conjunce tion with the accompanying drawings wherein:

. Fig. 1 is a vertical cross-section of a househeating, low-pressure boiler, showing the use of the inserts embodied in my invention.

Fig. 2 is a perspective View showing a form of insert embodied in my invention.

Fig. 3 is a section along line 3-3 of Fig. 2.

Fig. 4 is a fragmental view, partly in section, of an interior portion of a boiler showing the use of a pair of inserts disposed in the direct path of heating gases leaving through an opening or conduit in the boiler.

Fig. 5 is a perspective view illustrating another form of insert.

Fig. 6 is across-section along line 6-6 of Fig. 5.

Fig. 7 is a perspective view illustrating another form of insert specially adapted for attachment to the combustion chamber walls of a boiler.

Fig. 8 is an end elevation of the insert shown in Fig. '7.

Fig. 9 is a cross-section along line 9-9 of Fig. 7.

The type of insert shown in Fig. 2 is particularly adapted for attachment in the gas passageways of the heating device. This type embodies a metal pad or base I having integral rods or fingers 2. The heavy base portion I lends stability and serves as a heat accumulator as well as a highly elficient, heat-transfer agent. The insert is attached and bonded to the heater face sec- 40 tions 3 (see Fig. 4). By providing a close bond between the insert and the Wall to which it is affixed deposition of soot between the surfaces is prevented, thus eliminating a disadvantage to which loss in heat-transfer efficiency is traceable. The surface 3 of the base and the surface of the heater section 4 are preferably sandblasted, rough ground or otherwise properly fin ished so as to afford good seating faces at the place of attachment and thus yield a firm joint.

In a construction such as shown in Fig. 4, where the rods or fingers of the inserts project toward each other and are in the immediate vicinity of each other, a metal rod or bolt may be provided which passes through the bores 5 in the bases 1 and aids to hold the inserts in proper relation to each other.

In the type of insert shown in Figs. 5 and 6, the

fire pot Ill surrounded by an .auxiliary quick-heat- I ing water compartment serving as a water lining. The water in this auxiliary compartment derives heat from the combustion gases at their higher temperatures. This water compartment has a hollow floor section II and vertical wall sections l2, extending upwardly from the floor section. This auxiliary water compartment communicates with the main water compartment 1 3 only through the conduits Hand 15, the conduit [4 extending from the upper part of' the auxiliary water compartment to the upper part of the main water compartment and serves as an outlet for the hot water or steam, while the conduit I 5 extends from the lower part; of the main water compartment to the lower part of the auxiliary water compartment and serves as a return for the cooler water from the main water compartment to the auxiliary water compartment. If desired, water tobe heated may be supplied to the auxiliary water compartment from any other source of supply instead of or in addition to that from the main water compartment. The fire pot I0 opens into the heating gas chamber 1 6 which is constructed so that the heating gases will travel through a tortuous and elongated passageway before exiting through the outlet ll leading to a chimney (not shown) r The fire pot Ii) receives the combustion or other burning gases from any suitable source, preferably an oil burner 13 of the pressure atomizing type, the combustible mixture entering through the pipe I 8, commonly known as the wind pipe, and .being discharged as an ignited mixture into the fire pot.

The inserts are disposed at suitable locations on the wall separating the heating gas compartment I6 from the main water compartment 13 and are located above the refractory lining l 9 of plastic material. This refractory lining also thinly coats the :hollow sections II and I2 of the water lining. In the boiler shown in Fig. 1, inserts '20 of the type illustrated in Fig. 7 are disposed immediately above the refractory lining 19 while inserts 2| of the type illustrated in Fig. 5 are shown in the upper part of the heating gas chamher.

The inserts are applied to the existing heat absorbing surfaces of the heating device, by attaching or bonding them by means of a heat-conducting, heat-resisting cement, which provides a firm bond between the faces of the existing heatabsorbing surface and of the insert, thus assuring good conduction.

It is well known that when the gases of combustion in a heating device traverse the heat absorbing surfaces during their-passage to the smoke pipe or stack, that close to and at the surfaces of contact there is a substantially quiescent film .of gas and that the gas movement increases toward thecenter of the gas stream. As the amount of heat transferred through the heating surfaces depends considerably upon contact of the heated gases with these surfaces and upon their passage across them, much of the heat that is transferred through these surfaces reaches these surfaces by radiation through these surface layers of more or less immobile gases while the transfer of heat by convection and conduction are interfered with. Thus, a comparatively great Volume of gas moves at high temperature almost unimpeded through the gas passages and into the smoke pipe without releasing its heat value to the water in the boiler and carries with it much of its heat which is therebylost in high stack temperatures.

.By my apparatus the gas streams are broken up during their passage, into small turbulent streams which scrub over the surfaces of the heattransfer walls of the boiler and over the heat absorbing surfaces of the inserts at increased velocity, thereby increasing the rate of heat exchange over all of the heat absorption surfaces, and consequently increasing the amount of heat transferred through the heating surfaces to the water. With my invention, employing the same amount offuel the heat emission within the heated enclosure or house may thus be increased or, if desired, the same heat emission may be obtained with a reduction in the amount of fuel heretofore required.

My invention is particularly adapted to heating plants of relatively :small capacity. The heattransfer medium may be vapor, steam, hot water or any other medium or a combination of these media. My .invention is applicable to new installations as well as existing installations and can used to increase the heat absorbing capacity of existing installations by applying the inserts to the absorbing surfaces of existing apparatus.

An important benefit from my invention in thesei-nstances is in the efficient conversion to oil burner use, under the improved conditions, of existing devices which had been originally intended for :use with slow burning, solid fuels. By providing these inserts in fluid fuel burning boilers, even though-an accelerated rate of combustion occurs when this kind of fuel is burned, creating a considerable increase in the quantity of heat released in a given time and taking place frequently under conditions of forced draft and usually intermittently, nevertheless, the greater heat'absor-ption resulting effects a considerable reduction in heat losses and consequently increases the capacity-of the heater.

The units of my invention, which I call in- 'ser-ts are made of metal, preferably that which has good heat absorbing and heat transferring properties under the conditions of its use. These inserts are so shaped and of such design as to be easily and efiectivelyapplied to the various types, sizes, shapes and structures of the usual existing heat absorbing'sections of heating devices in current use. The rods or fingers provide several times as much heat absorbing surface as the area of contact between the pad and the water back surface of the boiler. Furthermore, this greatly increased heat absorbing surface is effectively placed directly in the path of the hot gases of combustion.

The materials employed for making a suitable plastic refractory for use in my boiler may be selected from a wide range of substances commonly employed in theboiler art and which include silicon carbide, raw fire clay, calcined fire clay,

magnesium oxide, chrome ores, mica, talc, quartz, 75

kaolin, diatomaceous and infusorial earths, tripoli, kieselguhr, alundum, fire brick, magnesite, ganister, Portland and hydraulic cements, gypsum, anhydride, volcanic scoriae, and slag. Some of these materials may be used alone, while all of these substances have been employed in combinations of two or more in various compositions, the proportions being varied to meet the particular needs and fancy of the manufacturer and/or user. These materials are comminuted to the desired size and a suitable binder in liquid form is added to yield a plastic mixture suitable for molding and application as. may be desired.

In the specification and claims the term plastic refractory material has reference to a substance prepared from materials, such as described above, and which is plastic during its application and subsequently hardens.

The present invention is not limited to the specific details set forth in the foregoing examples which should be construed as illustrative and not by way of limitation, and in view of the numerous modifications which may be effected therein without departing from the spirit and scope of this invention, it is desired that only such limitations be imposed as are indicated in the appended claims.

I claim as my invention:

1. In a low pressure, fluid fuel burning boiler, a water compartment, a heating gas compartment adjacent thereto and separated therefrom by a heat-conducting, metallic wall, a fire pot adjacent to and communicating with said heating gas compartment, a heat-transfer element having a massive metallic base detachably and selectively secured by a heat-transmitting cement bond to said wall in close heat-transfer contact with a substantial area of the wall, and heat-conducting members projecting from said base into the heating gas compartment in the path of the heating gas, whereby the heat-transfer is increased and accelerated at selective locations.

2. In a boiler, a water compartment, a heating gas compartment adjacent thereto and separated therefrom by a heat-conducting, metallic wall, a heat-transfer element having a massive metallic base detachably and selectively secured by a heat-transmitting cement bond to'said wall in close heat-transfer contact with a substantial area of the wall, and heat-conducting members projecting from said base into the heating gas compartment in the path of the heating gas, whereby the heat-transfer is increased and accelerated at selective locations.

3. In a boiler, a water compartment, a heating gas compartment adjacent thereto and separated therefrom by a heat-conducting, metallic wall, a fire pot adjacent to and communicating with said heating gas compartment and having a lining of refractory material, a heat-transfer element having a massive, metallic base detachably and selectively secured by a heat-transmitting bond to said wall in close heat-transfer contact with a substantial area of the wall, and heat-conducting members projecting from said base into the heating gas compartment in the path of the heating gas, whereby the quantity and rate of heattransfer is adjusted at selective locations.

4. In a house-heating boiler, a water compartment, a heating gas compartment adjacent thereto and separated therefrom by a heat-conducting, metallic wall, a heat-transfer element having a massive heat-accumulating, metallic base deseparated therefrom by a heat-conducting, metallic wall, a heat-transfer element having a massive metallic base detachably and selectively secured by a heat-transmitting cement bond to said wall in close heat-transfer contact with a substantial area of the wall, heat-conducting members projecting from said base into the heating gas compartment in the path of the heating gas, whereby the heat-transfer is increased and accelerated at selective locations, a fluid fuel burner, a fire pot having a water lining constituting an auxiliary quick-heating water compartment and comprising a floor section and a wall section communicating with and extending upwardly from said floor section, said main water compartment and auxiliary compartment being connected for fluid circulation by an outside conduit from the water lining to the main water compartment,

6. In a house-heating boiler, a main water compartment, a heating gas compartment adjacent thereto and separated therefrom by a heatconducting, metallic wall, a heat-transfer element having a massive, heat-accumulating, metallic base detachably and selectively secured by a heattransmitting cement bond to said wall in close heat-transfer contact with a substantial area of the wall, elongated, metallic, heat-conducting rods projecting from said base into the heating gas compartment in the path of the heating gas, whereby the quantity and rate of the heat-transfer is adjusted at selective locations, a fluid fuel burner, a fire pot having a water lining constituting an auxiliary quick-heating water compartment and comprising a floor section and a wall section communicating with and extending upwardly from said floor section, said main water compartment and auxiliary water compartment being connected for fluid circulation by an outside conduit from the upper part of the water lining to the upper part of the main water compartment and by another outside conduit from the lower part of the main water compartment to the lower part of the water lining, and a thin coating of plastic refractory material on said floor section and wall section.

7. In a boiler, a water compartment, a heating gas compartment adjacent thereto and separated therefrom by a heat-conducting, metallic wall, a fire pot adjacent to and communicating with said heating gas compartment and having a lining .of plastic refractory material, a heattransfer element having a massive, metallic base detachably and selectively secured by a heattransmitting cement bond to said wall in close heat-transfer contact with a substantial area of the wall, and heat-conducting members projecting from said base into the heating gas compartment in the path of the heating gas and beyond the flame zone, whereby the quantity-and rate of the heat-transfer is adjusted at selective locations.

MORA S. HALL.

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