US2045668A - Mineral wool furnace - Google Patents

Description

June 3@, 1936. T' MOONEY MINERAL WOOL FURNACE Filed June 17, 1955 Ina/6222 07"; T/LOWZQJFMOQ MM w 1% Lav (.1, M

Patented June 30, 1936 UNITED STATES PATENT OFFICE ltflNERAL WOOL FURNACE Application June 17, 1935, Serial No. 26,930

.2 Claims.

7 This invention relates to furnaces and more particuiarly to furnaces of the character employed in the production of mineral wool from slag, limestone, rock, shale, or other suitable mineral material.

The primary purpose of the invention is to provide a furnace which will utilize to a maximiun degree the heat units developed by the melting operation so that the furnace will possess an efiiciency greater than has heretofore been reached, and will also utilize the heat units generated in the furnace for the production of a pressure sufficient to reduce the liquid melted mineral to a fibrous condition known commercially as mineral wool.

A preferred embodiment of the invention is illustrated on the accompanying drawing. R'eferrlng to which:

Fig. 1 is aside elevation partially in section'of a furnace constructed in accordance with the principles of the invention, and

Figs. 2 and 3 are transverse sectional views taken on the lines 2-2 and 3-3 respectively of Fig. 1.

On the drawing the cupola of the furnace is indicated generally by reference character 4 and comprises a melting chamber 5 surrounded by a water jacket 6 which in turn is surrounded by an air jacket I. The cupola is supported upon a suitable base 8 at a sufficient elevation to permit the employment of a bottom 9 capable of being lowered to clean out the melting chamber, or a dumping bottom of suitable construction may be employed instead if preferred. The bottom is' preferably composed of fire-brick or other heat resisting materials which will not be subject to injury by the molten material produced in the cupola.

The cupola proper is surmounted by a. waste heat duct ll through which the products of combustion from the cupola rise, and this duct is provided with a charging opening normally closed by a door l2 through which the material with which the cupola is chargexi is introduced. While oil or gas may be used as fuel for melting the material, in which instance the cupola will be equipped with suitable oil or gas burners of any preferred type, the furnace .illustrated as exemplifying theinvention is designed to use solid fuel such as coal or coke which is loaded into the cupola through the door l2 so as to be arranged in the cupola in alternate layers with the material to be melted. The most complete combustion takes place near the bottom of the eupola where the forced draft air is intruced and the superposed layers of mineral material and fuel become heated up and finally the fuel is ignited whereby the mineral material is reduced to a molten condition. As the charge of fuel and material in the cupola is consumed, it is replen- 5 ished through the door 12 so that a continuous operation or an extended period operation may be carried on.

It will be observed that the water jacket 6 terminates below the level of the door l2 but is again resumed above the door as indicated at l3, this upper section of the water jacket being connected with and in fact forming a part of a vertical tube steam generating boiler I4 which surmounts, or in efi'ect forms, a continuation of 15 the waste heat duct II. The water jacket sections 6 and I3 are connected by pipes l5 through which water heated by the cupola is conducted to the boiler. The water for the furnace is replenished as required through a supply pipe I! connected with the supply source adapted to introduce the water against the pressure generated by the boiler.

The heat generated by the cupola and transmitted to the surrounding water jacket 6, to the water jacket I 3 and to the boiler ll generates steam in this boiler which is utilized for the conversion of the molten mineral as will be later explained. These heat units which are conserved in the generation of steam represent a large saving in heat loss which customarily, in furnaces'of this character, has escaped through the stack. The steam thus generated is conducted from the boiler through a pipe l8 to a superheater l9 consisting of suitably arranged 5 coils positioned in the waste heat duct ll below the boiler proper where it is subjected to the intense heat arising directly from the cupola. Suitable safety valves 2| and 22 are employed to preclude the generation of adangerously high 40 steam pressure. From the superheater the steam is conducted by a pipe 23 to a discharge nozzle 24 located or adjustably positioned in proper relation to the delivery orifice 25 from the cupola so that the steam issuing under high pressure from the nozzle impinges against the stream of molten mineral flowing from the cupola whereby the molten mineral is reduced to a fibrous flufly condition and is blown into a. cooling and storage chamber (not shown) from which, after cooling, it may be removed for use.

For the purpose .of further conserving the heat units generated in the cupola, I have surrounded the stack 26 through which the products of combustion issuing from the boiler escape to atmos-= phere by a jacket 21 opening to atmosphere and forming an air inlet passage for the air employed for the forced draft operation. The air entering the jacket around the stack becomes heated by the stack and is conducted through a conduit 28 to a blower 29 which discharges through a conduit 3| into the air jacket I where this air is further heated from the hot water jacket surrounding the cupola. Air inlet openings 32 of any desired number establish communication between the air jacket I and the interior of the furnace near the bottom of the melting chamber through which the heated air is delivered under pressure into the combustion chamber to produce a hot blast forced draft condition within the chamber which facilitates the combustion and greatly increases the efiiciency of the furnace.

It will be manifest from the foregoing that a furnace constructed in accordance with my invention utilizes a large proportion of the waste heat from the melting cupola, which is customarily lost, for generation of steam pressure which is employed in disintegrating the molten mineral and for heating the air delivered to the cupola for draft purposes so that the temperature of the cupola is not reduced as it would be by the introduction of atmospheric air. The productionof steam by the otherwise waste heat provides a suitable pressure supply for reducing the molten mineral to fiberized condition, thereby eliminating the usual apparatus for, and cost of production of, compressed air or steam customarily used for this purpose.

rounding said chamber and an air jacket surrounding the water jacket, a waste heat duct leading from the melting chamber, a steam superheater in said duct, a boiler through which products of combustion are delivered from said 5 duct, a pipe connection between said water jacket and said boiler, a pipe connection between the boiler and the superheater, a nozzle in proximity to the bottom of the melting chamber, a. connection between thesuperheater and said nozzle, a stack leading from said boiler, a jacket surrounding said stack, a blower having its inlet side connected with said stack jacket and its outlet connected with said air jacket, and ducts establishing communication between said air jacket and the lower portion of said melting chamber through which heated air for draft purposes is delivered into said chamber.

2. A mineral wool furnace comprising a cupola including a melting chamber, a water jacket 20 therefor and an air jacket surrounding the water jacket, a waste heat duct leading from the cupola and provided with a cupola charging opening, a steam generating boiler communicating with said duct, a stack leading from said boiler, pipes 2 establishing a circulating connection between said water jacket and said boiler, a steam superheater located in said duct, means for conducting steam from said boiler to said-superheat'er, a steam delivery nozzle located in proximity to the lower end of the cupola, means for conducting steam .from said superheater to said nozzle, an air heating jacket surrounding said stack, ducts establishing communication between said air jacket 35 and said melting chamber, and means for delivering air heated by said stack jacket through said air jacket and ducts into said melting chamber.

THOMAS F. MOONEY. 40

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