US3678870A - Sludge burner - Google Patents

Abstract

An incinerator that is particularly adapted to burn sludge type materials alone or in combination with the usual solid wastes.

Description

United States Patent Bakker [151 3,678,870 [451 July 25, 1972 I54] SLUDGE BURNER [72] Inventor: Lubertus Bakker, Wellsville, NY.

[73] Assignee: The Air Preheater Company, 1nc., Wellsville, NY.

[22] Filed: May 20, 1971 App1.No.: 145,144

[52] U.S.Cl. ..l10/8R [51] Int. Cl ..F23g 5/00 [58] FieldofSearch ..110/8 R,8A, 18R

[56] References Cited UNITED STATES PATENTS 3,312,183 4/1967 Kells et a1. ..110/8 3,344,758 10/1967 Wotschke ..110/18 3,491,707 1/1970 Bakker ..110/8 FOREIGN PATENTS OR APPLICATIONS 1,104,605 2/1968 Great Britain ..1 10/8 Primary ExaminerKenneth W. Sprague Allorney-Wayne H. Lang and Eldon H. Luther [57] ABSTRACT An incinerator that is particularly adapted to burn sludge type materials alone or in combination with the usual solid wastes.

8 Claims, 3 Drawing Figures Patented July 25, 1972 7 3,678,870

INVENTOR. [vie/z? fiaz/ BY "fl w SLUDGE BURNER BACKGROUND OF THE INVENTION l. Field of the Invention The present invention relates to an arrangement for an incinerator that is especially adapted to burn sludges of various viscosities without the accompaniment of smoke, fly ash or odor. The sludge burning capability of this invention is in addition to the customary adaptability of the incinerator to the burning of solid wastes.

2. Description of Prior Art Incineration of waste material has long been an accepted method of refuse disposal whereby carbonacious material is reduced to gaseous material and ash. However, most instances of waste disposal in this manner relate to solid waste materials burned in a conventional incinerator. If the waste material to be incinerated exists in liquid or semi-liquid form as a sludge, past practice has dictated that the sludge merely be sprayed into the chamber of an incinerator as a conventional liquid fuel. Upon entry into the hot combustion chamber, it is intended that the moisture of the spray will be evaporated and the residue then burned. Such spray feeding is usually therefore designed to project droplet sized particles of fuel into a combustion chamber in a manner that permits the particles to be contacted momentarily by the hot combustion gases and burn. If the droplets should contain excess moisture or if their content is not readily reduced by combustion, they tend to be entrained in gas stream and be carried out the exhaust duct into the atmosphere. Moreover, in my U.S. Pat. No. 3,491,700, some of the combustion air is supplied to the incinerator chamber in such a manner that it travels upward along the walls to absorb heat therefrom and cool its surface. In this manner air is preheated and excessive wall temperatures are avoided. However, such air in turn avoids direct contact with droplets or particulate waste being sprayed downwardly to the central portion of the incinerator chamber. Thus the result is poor mixing of the combustion air and sprayed fuel and a correspondingly poor rate of combustion.

SUMMARY OF THE INVENTION This invention provides an incinerator having a unique incineration chamber that is especially adapted to burn liquid or semi-liquid fuel in the form of a combustible sludge by increasing the residence time during which the fuel is in contact with the hot gases of combustion.

It is moreover an objective of this invention to provide a device which will simultaneously burn solid fuel and liquid fuel or sludge in separate zones of the incinerator without any interference therebetween.

A further objective of this invention is to provide a sludge burner that will effectively handle sludges of varying viscosity and having a widely varying BTU content.

A BRIEF DESCRIPTION OF THE DRAWING FIG. 1 shows a perspective view of an incinerator adapted to handle sludges in accordance with this invention FIG. 2 is a perspective view of an incinerator showing the relationship of sludge supply manifold and supply tubes, and

FIG. 3 is an enlarged view of sludge supply tube as mounted in the incinerator.

DESCRIPTION OF THE PREFERRED EMBODIMENT In an incinerator of the starved air type, trash or refuse to be burned is placed in an incinerator housing enclosing a primary combustion chamber 12 that is preferably formed in an ellipsoidal configuration in the manner taught by my U.S. Pat. No. 3,419,700 granted Jan. 27, I970. The incinerator is formed with a loading or access door 14 at one end for the supply of solid material to be burned and an outlet port 16 at the other end for the exhaust of products of combustion therefrom. The inner wall of the incinerator is insulated by a layer of fire resistant material 18 capable of withstanding temperatures ranging upwards to approximately 2,5 00 F.

The bottom of the vessel is adapted to receive a series of tubes 20 having openings 22 therein sized to provide adequate air for combustion of a charge placed therein. As an arrangement that protects the tubes from the corrosion and erosion of the burning waste the tubes may be embedded in the insulating material so only the exit openings 22 for the air are connected via valve 25 in line 27 to a suitable outside source of air for combustion whereby sufficient air may at all times be supplied to the primary combustion chamber.

In the same manner that tubes 20 are embedded in the insulation layer lining the floor of the incinerator, sludge supply tubes 26 are embedded in the insulation lining the upper portion of the incinerator. Thus liquid waste or sludge supplied to the upper ends of the tubes 26 may flow downwardly through the tubes so that it is heated while passing in heat exchange relation with the hot insulating material which lies in contact with the combustion gases. As the hot sludge is exhausted from the belled outlets 28 it usually has a low viscosity because of its high water content, but as it flows downwardly over the walls of the incinerator it quickly loses moisture by evaporation and is subsequently burned or subjected to pyrolosis according to a predetermined incineration process.

The tubes 26 are attached to a header or manifold 30 that is supplied with sludge from a source via an inlet pipe 32. The sludge is preferably fed through pump 40 and valve 42 whereby the proper amount of sludge may be supplied to the tubes 26 and exhausted from the belled outlets. While some of the sludge may be blown from the belled ends 28 of the tubes into the incinerator chamber, a major portion of it will gravitate downwardly and follow the curvature of the wall as a slowly moving stream flowing to the bottom of the incinerator.

As the sludge flows down through the tubes 26 and out the belled ends thereof it is heated and the moisture therein is lost by evaporation leaving a dry residue or cake. This cake is summarily subjected to a continued pyrolosis according to standard starved air" incineration principles until only an inert ash remains.

To enable the effective burning of all sludge in spite of its varying calorific value, the flow of sludge to the incinerator chamber may be controlled in accordance with the temperature in the chamber obtained by the partial combustion of the waste material therein. Accordingly, a thermocouple 44 in the primary combustion chamber is adapted to sense the temperature of the heat generated therein and activate a controller 46 that regulates operation of the sludge supply valve 42 and the air supply valve 25. Thus the thermocouple 44 is adapted to sense the heat of the combustion chamber to activate a controller whereby a temperature in excess of a predetermined amount will move valves 25 and 42 toward a closed position. Similarily insufficient heat at thermocouple 44 will actuate the controller 46 to move the air and fuel valves toward an open position to increase the combustion rate in the chamber 14.

While this invention has been directed to a preferred embodiment, it will be obvious to those skilled in the art that various modifications and changes may be made without departing from the spirit of the invention. It is therefore intended that the embodiment defined is illustrative only and not restrictive of the invention, the scope of which is defined only by the appended claims.

I claim:

1. An incinerator for the burning of an aqueous sludge therein comprising a housing defining a substantially airtight combustion chamber, a loading port for solids and an exhaust port for gas in said housing, passageways traversing the housing wall having outlet ports that exhaust into said chamber,

'and means for supplying a quantity of sludge to said passageways whereby the sludge will exhaust from said outlet ports and flow down the chamber wall after it is discharged from said ports to present a film of flowing sludge to the hot combustion gases.

2. An incinerator for the burning of a sludge therein comprising a housing defining a substantially airtight combustion chamber, a layer of insulafing material coating the inner surface of said housing, a plurality of downwardly inclined passageways embedded in said insulating material and having outlet ports that exhaust into said combustion chamber, and manifold means connected to said passageways to supply a combustible sludge thereto whereby said sludge will be preheated as it flows through said passageways and will exhaust from the ports and flow down the chamber wall.

3. An incinerator for the burning of sludge therein as defined in claim 2 wherein the downwardly inclined passageways embedded in walls of the combustion chamber are on opposite sides of the incinerator housing.

4. An incinerator for the burning of sludge therein as defined in claim 2 wherein the exhaust ports at the sides of the incinerator chamber are faired to wall of the incinerator chamber to provide a smooth transition zone between the passageways and the combustion chamber.

5. An incinerator for the burning of sludge therein as defined in claim 2 wherein the inclined passageways are substantially concentric with the walls of the combustion chamber.

6. An incinerator for the burning of sludge therein as defined in claim 2 wherein the slope of the incinerator chamber lying below the outlet ports for the several passageways decreases progressively to thereby increase the resistance to sludge flowing downward from said outlet ports.

7. An incinerator for the burning of sludge therein comprising a housing defining a substantially airtight combustion chamber, a loading port for the loading of solid wastes into the incinerator, door means adapted to close the loading port, an exhaust port in the housing for the exhaust of gaseous products of combustion therefrom, a series of outlet ports on opposite sides of the chamber wall, passageways extending downwardly to said ports, a manifold connected to said passageways on opposite sides of the chamber walls, a source of liquified sludge, means for supplying the liquified sludge to said manifold, a temperature responsive means in the combustion chamber and means for regulating the flow of sludge into the incinerator chamber in response to the temperature in the incineration chamber as sensed by the temperature responsive means.

8. An incinerator for the burning of sludge therein as defined in claim 7 including a layer of insulating material covering the passageways on opposite sides of the chamber wall adapted to protect said passageways from the corrosion and erosion of combustion in said chamber while it simultaneously absorbs heat therefrom.

Claims (8)

1. An incinerator for the burning of an aqueous sludge therein comprising a housing defining a substantially airtight combustion chamber, a loading port for solids and an exhaust port for gas in said housing, passageways traversing the housing wall having outlet ports that exhaust into said chamber, and means for supplying a quantity of sludge to said passageways whereby the sludge will exhaust from said outlet ports and flow down the chamber wall after it is discharged from said ports to present a film of flowing sludge to the hot combustion gases.

2. An incinerator for the burning of a sludge therein comprising a housing defining a substantially airtight combustion chamber, a layer of insulating material coating the inner surface of said housing, a plurality of downwardly inclined passageways embedded in said insulating material and having outlet ports that exhaust into said combustion chamber, and manifold means connected to said passageways to supply a combustible sludge thereto whereby said sludge will be preheated as it flows through said passageways and will exhaust from the ports and flow down the chamber wall.

3. An incinerator for the burning of sludge therein as defined in claim 2 wherein the downwardly inclined passageways embedded in walls of the combustion chamber are on opposite sides of the incinerator housing.

4. An incinerator for the burning of sludge therein as defined in claim 2 wherein the exhaust ports at the sides of the incinerator chamber are faired to wall of the incinerator chamber to provide a smooth transition zone between the passageways and the combustion chamber.

5. An incinerator for the burning of sludge therein as defined in claim 2 wherein the inclined passageways are substantially concentric with the walls of the combustion chamber.

6. An incinerator for the burning of sludge therein as defined in claim 2 wherein the slope of the incinerator chamber lying below the outlet ports for the several passageways decreases progressively to thereby increase the resistance to sludge flowing downward from said outlet ports.

7. An incinerator for the burning of sludge therein comprising a housing defining a substantially airtight combustion chamber, a loading port for the loading of solid wastes into the incinerator, door means adapted to close the loading port, an exhaust port in the housing for the exhaust of gaseous products of combustion therefrom, a series of outlet ports on opposite sides of the chamber wall, passageways extending downwardly to said ports, a manifold connected to said passageways on opposite sides of the chamber walls, a source of liquified sludge, means for supplying the liquified sludge to said manifold, a temperature responsive means in the combustion chamber and means for regulating the flow of sludge into the incinerator chamber in response to the temperature in the incineration chamber as sensed by the temperature responsive means.

8. An incinerator for the burning of sludge therein as defined in claim 7 including a layer of insulating material covering the passageways on opposite sides of the chamber wall adapted to protect said passageways from the corrosion and erosion of combustion in said chamber while it simultaneously absorbs heat therefrom.

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