US3841241A

US3841241A - Ash removal system for incinerators

Info

Publication number: US3841241A
Application number: US00378657A
Authority: US
Inventors: E Dewey; R Clements
Original assignee: Environmental Control Products Inc
Current assignee: Environmental Control Products Inc
Priority date: 1973-07-12
Filing date: 1973-07-12
Publication date: 1974-10-15
Anticipated expiration: 1991-10-15

Abstract

The improvement, in an incinerator, of conveyor means for automatically removing the burnt material or ash from the ash pit of the incinerator and for transporting it to a remote location. A control is provided for automatically operating the conveyor and a temperature sensing device is provided in the ash pit for stopping the conveyor when the accumulation of ash is reduced to a minimum predetermined amount. It is preferable that the conveyor operating cycle be initiated when the incinerator charging door is opened to permit the feeding of the material to be burned from an automatic feed means.

Description

[ 1 Oct. 15,1974

United States Patent [191 Dewey et al.

3,667,627 6/1972 Martin ct 3,728,977 4/1973 Brannan............. 3,749,031 7/1973 Burden, Jr.

[ ASH REMOVAL SYSTEM FOR INCINERATORS Primary ExaminerKenneth W. Sprague Attorney, Agent, or Firm-Parrott, Bell, Seltzer, Park & Gibson [75] Inventors: Ernest A. Dewey, Richmond, Va.;

Richard F. Clements, Charlotte, NC.

Environmental Control Products,

[73] Assignee:

Inc., Charlotte, NC.

July 12, 1973 [21] Appl. No.: 378,657

[57] ABSTRACT I The improvement, in an incinerator, of conveyor [22] Filed:

means for automatically removing the burnt material or ash from the ash pit of the incinerator and for transporting it to a remote location. A control is provided for automatically operating the conveyor and a temperature sensing device is provided in the ash pit for stopping the conveyor when the accumulation of ash is reduced to a minimum predetermined amount. It is preferable that the conveyor operating cycle be initiated when the incinerator charging door is opened to permit the feeding of the material to be burned from an automatic feed means.

12 Claims, 6 Drawing Figures RmwR fifix 1 HH 65 6 00ml 1 1 11 mumw .m l l ..1 1F "m. R N s T. ..u m m N m: 0 E m: 1 v T n ."O WA "u" in. W: "m S mm mmm r. m nu cT .m "N" nA n mmm mTa U" .RSRWM h e R 0 m. 57 UIF 377 HUN M mun 555i U 2 2 3 ASH REMOVAL SYSTEM FOR INCINERATORS The present invention relates generally to an ash removal system for incinerators and more particularly to such a system which is automatically controlled in response to the feeding of waste material into the incinerator.

Heretofore, various types of systems have been proposed for the removal of the burnt material or ash from the ash pit of an incinerator. However, these prior systems have either operated on a continuous basis or on an automatic time cycle. In either case, it is difficult to properly adjust the ash removal system to the proper burning cycle so that the ash is removed at the proper rate. If too great an amount of ash is permitted to accumulate, it will adversely effect the burning of the waste material. If too small an amount of ash is in the ash pit, the heat from the combustion chamber can adversely effect the ash removal mechanism.

Accordingly, it is an object of this invention to provide an ash removal system which overcomes the difficulties and problems presented in prior ash removal systems and which is characterized by being operable in response to the feeding of waste material to be burned and maintains the proper amount of ash in the ash pit.

This object is accomplished in the present invention by providing a conveyor communicating with the ash pit and being operable to remove the ash from the ash pit and transport it to a remote location. A control is provided for automatically initiating the operating cycle of the conveyor in response to the feeding of waste material to be burned into the combustion chamber. A temperature sensing device is provided in the ash pit for interrupting the operating cycle and stopping the conveyor when the accumulation of ash is reduced to a minimum predetermined amount. The operating cycle of the ash removal system is preferably initiated when the incinerator charging door is opened to receive the waste material from the automatic feed means for the incinerator.

Other objects and advantages of the invention will appear as the description proceeds, when taken in connection with the accompanying drawings, in which-- FIG. 1 is an isometric view of an incinerator of the type having a main and secondary combustion chamber and illustrating the present ash removal system applied thereto;

FIG. 2 is an enlarged fragmentary vertical sectional view taken substantially along the line 22 in FIG. 1;

FIG. 3 is a longitudinal vertical sectional view taken substantially along the line 33 in FIG. 1 and illustrating the manner in which the endless drag chain passes through the ash pit of the incinerator;

FIG. 4 is a sectional plan view taken substantially along the line 44 in FIG. 3;

FIG. 5 is a vertical sectional view taken substantially along the line 5-5 in FIG. 3; and

FIG. 6 is a somewhat schematic and diagramatic view of the incinerator, illustrating a portion of the ash removal system and illustrating the controls for the operation of the ash removal system.

The ash removal system of the present invention is illustrated and described in operation with a controlled emission incinerator apparatus of the type disclosed in US. Pat. No. 3,543,700, issued Dec. 1, 1970, and assigned to the present assignee. This incinerator is illustrated as being provided with an access or charging door of the type disclosed in US. Pat. No. 3,669,040, issued June 13, 1972, and assigned to the present assignee. The automatic feed means, illustrated in dotted lines in FIG. 6, may be of the general type disclosed in US. Pat. No. 3,708,078, issued Jan. 2, 1973, and assigned to the present assignee. However, it is to be understood that the ash removal system of the present invention may be used in connection with other types of incinerators which may be provided with different types of devices for manually or automatically feeding the waste material into the incinerator to be burned.

Referring particularly to FIG. 1, the controlled emission incinerator includes a main combustion chamber, broadly indicated at 10, which communicates with a secondary combustion chamber 11, and exhaust stack means 12 having the lower end thereof communicating with the interior of the secondary combustion chamber 11. As best shown in FIG. 3, an ash pit 13 is provided in the forward end of the main'combustion chamber 10 and is preferably lined with refractory material of the type which is normally used in an incinerator.

The ash removal system of the present invention comprises means for automatically removing the burnt ash from the ash pit 13 and conveying it to a remote location where it may be deposited in suitable containers or a truck or the like. The conveyor means comprises an endless drag chain 14 which removes the ash from the ash pit 13 and deposits it upon the horizontal portion of an elevator conveyor, broadly indicated at 15 (FIG. 2). Drive means, in the form of an electric motor 16 (FIG. 2) is provided for imparting movement to the drag chain 14 and in a manner to be presently described.

Opposite end portions of the drag chain 14 are suitably supported on sprockets 17, 18 (FIG. 3) and the sprocket 17 is preferably supported for adjustment to maintain the drag chain 14 under the proper tension. The upper reach of the drag chain 14 extends through the bottom of the ash pit 13 and enters the ash pit through an entry opening 20 and leaves the ash pit through an exit opening 21 having a doctor gate 22 supported for vertical movement in the exit opening 21 and above the drag chain 14. Means, to be presently described, is provided for adjusting the vertical position of the doctor gate 22 to thereby aid in determining the amount of ash which is removed from the ash pit 13 by the drag chain 14. The drag chain 14 is surrounded by support framing and a housing 24 which is provided with access doors 25 at suitable locations to permit inspection and access to the drag chain 14.

The doctor gate 22 (FIGS. 3 and 5) is vertically adjustable by a means of a hand wheel 27 which is fixed on one end of a control shaft 28. The control shaft 28 is supported for rotation in the housing 24 and has

pinions

29, 30 fixed thereto which engage

respective racks

31, 32 supported on the gate 22. Thus, by rotating the wheel 27, the gate 22 may be raised or lowered above the upper surface of the upper reach of the drag chain 14 to thereby vary the size of the exit opening 21 and permit a greater or lesser amount of ash to be removed from the ash pit 13.

The ashes removed by the drag chain 14 are carried along to an opening 35 (FIG. 3) beneath a wire brush 36 where they fall by gravity onto the horizontal flight of the elevator conveyor 15. A rectangular housing 40 surrounds the elevator conveyor and extends upwardly from the housing 24 surrounding the drag chain 14. The ashes transferred from the drag chain 14 and onto the conveyor 15 are raised upwardly and discharged at the upper end, as illustrated in FIG. 1, into any suitable container or removal truck or the like. As shown in FIG. 1, drive means in the form of an electric motor 41 is provided for imparting driving movement to the elevator conveyor 15.

As best illustrated in FIGS. 2 and 3, the drive motor 16 imparts movement to the drag chain 14 by means of a reduction drive unit 43, a drive sprocket 44, a chain 45, and ,a sprocket 46 which is fixed on a drive shaft 47. The drive shaft 47 is supported for rotation in the housing 24 and the sprocket 18 is fixedly supported on the drive shaft 47.

In accordance with the present invention, temperature sensing means is positioned in the ash pit 13 and is operable to stop the conveyor means when the amount of ash accumulated in the ash pit is reduced to a minimum predetermined amount. In the present instance, the temperature sensing means is in the form of a thermocouple type sensor 50 (FIG. 6) which extends into the ash pit 13 and is connected by wires 51, 52 to an adjustable control switch 53. The control switch 53 is adjusted so that the drive means for the conveyor means is interrupted when the accumulation of ash in the ash pit is reduced to a minimum level. It is to be understood that the thermocouple sensor 50 and the control switch53 operate in response to the temperature in the ash pit, which is determined by the amount of ash present therein. Thus, the temperature at the location of the thermocouple 50 is reduced when the ash pit is substantially full of ashes and is increased as the accumulation of ash in the ash pit is reduced. This insures that a sufficient protective layer of ashes is always present to prevent damage to the drag chain 14 from the heat in the combustion chamber 10.

The control switch 53 is connected at one side to a main line 54 by means of a wire 55 and is connected at its other side to a main line 56 by a wire 57. The control switch 53 is also connected to a solenoid switch 58 by a wire 59. A wire 60 connects the other side of the solenoid switch 58to the main line 56. The main line 56 is connected to one side of an ash removal drive motor starter 62 and the other side is connected to the main line 54. A solenoid switch 63 is interposed in the main line 54 and is connected by a wire 64 to the main line 56. A wire 65 extends from the other side of the solenoid switch 63 and to one side of the solenoid switch 58. A wire 66 is connected to the other side of the solenoid switch 58 and its other end is connected to one side of a timer controlled solenoid switch 67. A wire 68 connects the other side of the switch 67 to the main line 54. A normally open charging door operated switch 69 is connected at one side to the wire 66 by a wire 70. A wire 71 is connected at one end to the other side of the switch 69 and its other end is connected to the main line 54. The switch 69 is normally open and it closes when the incinerator access or charging door 72 is opened.

METHOD OF OPERATION When the automatic feed means 73 operates and the 6 door 72 opens, the switch 69 closes to close the switch 63 and complete the circuit to the drive motor starter 62 and start the operating cycle of the ash removal system. The timer switch 67 is actuated when switch 63 is closed and the drag chain 14 will normally continue to operate for the time set on the timer switch 67. However, if enough ash is removed to increase the temperature in the ash pit 13 a sufficient amount to close control switch 53, the circuit will be completed to switch 58 and it will open, thereby opening switch 63 and breaking the circuit to the ash removal drive motor starter 62 so that movement of the drag chain is interrupted.

If desired, the ash removal drive motor starter 62 can also operate the elevator conveyor drive motor 41. However, it is preferred that the elevator conveyor 15 operate continuously while the incinerator is in operation. Thus, the drive means for the conveyor means is actuated each time the charging door 72 is opened and the automatic feed means 73 is operated. The ash removal system continues to operate, unless interrupted by the operation of switch 53, until the pre-set time cycle is completed.

If desired, the control circuit of the ash removal system of the present invention may be changed so that the drag chain 14 is automatically operated to remove the ash from the ash pit in response to the temperature in the ash pit 13. In this case, the switch 53 would control the main line switch 63 to the drive motor starter 62. Then, the ash removal system would operate when a predetermined amount of ash accumulates in the pit and would also operate to stop the ash removal system when the amount of ash in the ash pit is reduced a given amount below the predetermined amount.

The incinerator charging means is illustrated and described as including the charging door 72 and the single ram type automatic feed means 73. However, it is to be understood that the charging door 72 can be eliminated if an automatic feed means is used which includes double rams, of the type described in said US. Pat. No. 3,708,078. In this case, the switch 69 would be closed by the operation of the automatic feeder. Also, the incinerator may be manually charged and the opening of the charging door would still close the switch 69 and start the ash removal cycle.

In the drawings and specification there has been set forth a preferred embodiment of the invention, and although specific terms are employed they are used in a generic and descriptive sense only and not for purposes of limitation.

That which is claimed is:

1. In an incinerator including a combustion chamber for burning waste material, means for charging the combustion chamber with waste material, and an ash pit for receiving burnt material, the combination therewith of means for automatically removing the burnt material from said ash pit, said means comprising a. conveyor means communicating with said ash pit and being operable to remove the burnt material therefrom,

b. drive means for imparting movement to said conveyor means, and

0. control means for actuating said drive means for a predetermined period and in response to each operation of said charging means.

2. In an incinerator, as set forth in claim 1, wherein said charging means comprises feeding means operable to automatically feed waste material into said combustion chamber in a periodic manner.

3. In an incinerator, as set forth in claim 2, wherein said feeding means comprises a charging door, and a single ram automatic feed means.

4. In an incinerator, as set forth in claim 2, wherein said feeding means comprises a double ram automatic feed means.

5. In an incinerator, as set forth in claim 1, wherein said conveyor means (a) comprises an endless drag chain having an upper reach extending through the bottom of said ash pit, an entry opening in one side of said ash pit and an exit opening in the opposite side of said ash pit for entry and exit of said drag chain, a doctor gate supported for vertical movement in said exit opening of said ash pit and above said drag chain, and means for adjusting the vertical position of said doctor gate above the upper level of said drag chain to thereby aid in determining the amount of waste material removed from said ash pit by said drag chain.

6. In an incinerator, as set forth in claim 5, including a burnt material elevator conveyor having one end portion positioned beneath said upper reach of said drag chain for receiving burnt material therefrom, said elevator extending upwardly therefrom for elevating the burnt material and discharging the same at a level above said drag chain.

7. In an incinerator, as set forth in claim 6, wherein said drive means comprises a first electric motor drivingly connected to said drag chain, and a second electric motor drivingly connected to said burnt material elevator conveyor.

8. In an incinerator, as set forth in claim 7, wherein said first electric motor is operable in response to operation of said control means, and wherein said second electric motor is continuously operated independently of said control means.

9. In an incinerator including a combustion chamber for burning waste material, and an ash pit for receiving burnt material, the combination therewith of means for automatically removing the burnt material from said ash pit, said means comprising:

a. conveyor means communicating with said ash pit and being operable to remove the burnt material therefrom,

b. drive means for imparting movement to said conveyor means, and

c. control means for actuating said drive means for a predetermined time period and in response to each operation of said charging means and including temperature sensing means positioned in said ash pit for preventing the operation of said drive means and for stopping the normal operating period of said drive means when the accumulation of burnt materials in said ash pit is reduced below a predetermined amount which causes the temperature in said ash pit to exceed a predetermined level.

10. In an incinerator, as set forth in claim 9, wherein said conveyor means comprises an endless drag chain having an upper reach extending through the bottom of said ash pit, and a burnt material elevator conveyor having one end positioned beneath said upper reach of said drag chain for receiving burnt materials therefrom and extending upwardly therefrom for elevating the burnt materials and discharging the same at a level above said drag chain.

11. In an incinerator, as set forth in claim 10, wherein said drive means comprises a first electric motor drivingly connected to said drag chain and operable in response to operation of said control means, and a second electric motor drivingly connected to said burnt material elevator conveyor and being continuously operated independent of said control means.

12. In an incinerator, as set forth in claim 9, wherein said control means further includes an adjustable control switch operatively connected to said temperature sensing means for selectively varying the predetermined temperature level at which the normal operating period of said drive means is stopped.

Claims

1. In an incinerator including a combustion chamber for burning waste material, means for charging the combustion chamber with waste material, and an ash pit for receiving burnt material, the combination therewith of means for automatically removing the burnt material from said ash pit, said means comprising a. conveyor means communicating with said ash pit and being operable to remove the burnt material therefrom, b. drive means for imparting movement to said conveyor means, and c. control means for actuating said drive means for a predetermined period and in response to each operation of said charging means.

9. In an incinerator including a combustion chamber for burning waste material, and an ash pit for receiving burnt material, the combination therewith of means for automatically removing the burnt material from said ash pit, said means comprising: a. conveyor means communicating with said ash pit and being operable to remove the burnt material therefrom, b. drive means for imparting movement to said conveyor means, and c. control means for actuating said drive means for a predetermined time period and in response to each operation of said charging means and including temperature sensing means positioned in said ash pit for preventing the operation of said drive means and for stopping the normal operating period of said drive means when the accumulation of burnt materials in said ash pit is reduced below a predetermined amount which causes the temperature in said ash pit to exceed a predetermined level.