US3682116A

US3682116A - Ash monitor and overcharge protection control system for incinerator

Info

Publication number: US3682116A
Application number: US97577A
Authority: US
Inventors: Paul W Spencer
Original assignee: NORTHEAST BURN ZOL CORP
Current assignee: NORTHEAST BURN ZOL CORP
Priority date: 1970-12-14
Filing date: 1970-12-14
Publication date: 1972-08-08
Anticipated expiration: 1989-08-08

Abstract

This disclosure is directed to an electromechanical control system by which the routine day to day operation of an incinerator is protected from certain hazards commonly associated with incinerator operation. The control system provides for automatic opening of a charging door when an operator approaches to insert burnable refuse, and for holding the charging door open while the operator is charging the incinerator. Provision is also made for limiting the total time during which the operator may engage in charging refuse into the incinerator. After this limited total time expires, the charging door, upon closing, will remain positively closed for a definite predetermined period of time to minimize explosion hazards in the event explosive objects, such as pressurized cans and stoppered bottles, are inadvertently charged into the incinerator. Provisions are also made for prohibiting firing of the incinerator unless the ashes are removed at the end of a predetermined period of incinerator operation, e.g., at least once every 24 hours. The arrangement is such that the incinerator is rendered inoperative for a predetermined period of time upon the opening of the ash removal door so as to provide for complete ash removal before operation can be resumed.

Description

United States Patent Spencer is] 3,682,l 16

1451 Aug. 8, 1972 [s41 ASH MONITOR AND OVERCHARGE PROTECTION CONTROL SYSTEM FOR INCINERATOR [72] Inventor: Paul W. Spencer, Morris Plains, NJ.

[73] Assignee: Northeast Burn-Z01 Corporation,

' Dover, NJ.

221 Filed: m.14,197o

21 Appl.No.: 97,577

521 U.S.Cl. ..ll0/8R,1l.0/176 51 1111. C1. ..F23g 5/00 [58] FieldolSearch ..uo/s,1s R, 18 E, 173, 176,

- [56] References Cited UNITED STATES PATENTS 2,960,046 11/1960 Clark ..110/173 X 3,141,426 7/1964 Zachow ..110/18 3,196,814 7/1965 Hahn et a1. ..110/18 3,330,231 7/ 1967 Spencer ..1 10/18 Primary Examiner-Kenneth W. Sprague Attorneylrving Seidman s71 ABSTRACT This disclosure is directed to an electromechanical control system by which the routine day to day operation of an incinerator is protected from certain hazards commonly associated with incinerator operation. The control system provides for automatic opening of a charging door when an operator approaches to insert bumable refuse, and for holding the charging door open while the operator is charging the incinerator.

Provision is also made for limiting the total time during which the operator may engage in charging refuse into the incinerator. After this limited total time expires, the charging door, upon closing, will remain positively closed for a definite predetermined period of time to minimize explosion hazards in the event explosive objects, such as pressurized cans and stoppered bottles, are inadvertently charged into the incinerator.

Provisions are also made for prohibiting firing of the incinerator unless the ashes are removed at the end of a predetermined period of incinerator operation, e.g., at least once every 24 hours. The arrangement is such that the incinerator is rendered inoperative for a predetermined period of time upon the opening of the ash removal door so as to provide for complete ash removal before operation can be resumed.

19 Claims, 8 Drawing Figures PATENTEDAU: a 1912 sum 1 or 5 AT TORNEY msmenws 1m SHEET 2 BF 3 INVENTOR. PRUL W. SPENCER A BY ATTORNE Y PATENTEMI: 8l972 3.682.116

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02 02 m.N m

E St $535 2:2;

A 7' TORNE Y ASH MONITOR AND OVERCHARGE PROTECTION CONTROL SYSTEM FOR INCINERATOR PROBLEMS AND PRIOR ART Poor operation of manually charged incinerator is generally attributed to overcharging and/or failure to remove the ashes. Overcharging results in throttling the circulation of combustion air which slows up the buming process. Failure to remove ashes results in ash accumulations which tend to reduce chamber volume and thereby inhibit burning. Also as the level of ash becomes progressively higher and higher above the bottom of the incinerator, the level of the fire eventually approaches the level of the charging doors. In such event hazardous items such as pressurized cans and stoppered bottles, if mistakenly charged into the furnace can explode. If such explosion occurs as the furnace door is open when an operator is charging the furnace, the operator can be seriously injured as a result thereof.

OBJECTS It is an object of this invention to provide an incinerator control system which will limit the amount of charge an operator may insert at any one time.

Another object is to provide a control system which will require a wait of a predetermined time interval after charging before additional refuse can be inserted into an incinerator.

Another object is to provide a control system which will render an incinerator inoperative if ashes have been allowed to accumulate for an excessive period of time, e.g., 24 hours.

Another object is to provide a control system which will automatically open an incinerator charging door as an operator is about to charge the incinerator.

Another object is to provide a control system which will prohibit incinerator operation for a predetermined time interval to provide for cleaning out of ashes.

Another object is to provide an incinerator control system which will inhibit the closing of a charging door if an operator happens to be in the act of loading refuse.

BRIEF SUMMARY OF INVENTION The foregoing objects, and other features and advantages are attained by a control system for an incinerator or the like which includes an ash monitoring and overcharge protection system. The system includes an overcharge protection monitor having a single cycle charge programmer comprising a plurality of cam wheels mounted on a common shaft actuated by an electrical motor. This programmer is set to make one revolution in a predetermined time interval to provide for the charging and overcharge protection features of the invention. In conjunction with this programmer, there is provided a first micro-switch which is actuated by the weight of an operator as he stands on a floor mat adjacent the incinerator charging door. There is also provided in the circuit a first starting solenoid which starts the programmer through its cycle, and a first safety relay which protects an operator who happens to be standing on the loading mat at the time the charge doors are to automatically close.

The system also includes a 24 hour time clock which emits a 12 minute pulse after 24 hours of running. This time clock pulse triggers the operation of a shut down programmer. The shut down programmer, like the charge programmer, comprises a plurality of cam wheels mounted on a single shaft turned by an electric motor. Associated switches in this programmer, operated by the cams, enable the programmer to shut down the incinerator by disabling theoperation of the charging door. A part of the system includes a second micro-switch which is closed and opened by the operation of the incinerators ash door. There is also an ash door relay which turns over control of the shut down programmer to the ash door during shut down. Finally there is a second safety relay which also is part of this system to cause the shut down programmer to be stopped in its cycle if an operator happens to be in the act of loading refuse when the cycle begins. The system is arranged so that when an operator ceases loading and moves off the loading mat the programmer resumes its rundown for ash removal.

FEATURES A feature of this invention resides in the combination of a floor mat utilized in circuit with a programmer to control the opening of an incinerator charging door whenever an operator steps on the mat to effect charging of the incinerator.

Another feature of this invention resides in the provision of a programmer to limit a maximum opening time of fixed duration for an incinerator charging door after which time the charging door will not open for a predetermined time period.

Another feature of this invention resides in the provision of a programmer to render the charge door open ing mechanism inoperative for a fixed period of time during which no further charge may be inserted.

Another feature of this invention resides in safety circuits which prevent an incinerator charging door from closing if an operator happens to be standing on the mat charging the incinerator.

Another feature of this invention resides in the combination of a timer with a shut down programmer to render the incinerator inoperative when ashes have been allowed to accumulate for a predetermined period.

Another feature of this invention resides in safety circuits to prevent the incinerator charging door from closing in response to a shut down signal if an operator is in charging position on the mat.

Another feature of this invention resides in electrical circuits which accumulate the time during which an ash door is in an open position so that the incinerator may not be put back into service prematurely.

Other features and advantages will become more readily apparent when considered in view of the specification and drawing in which:

FIG. 1A represents a schematic showing of an incinerator embodying the invention.

FIG. 1 is a schematic circuit diagram of the control system of this invention.

FIG. 2 is a profile view of a cam 1-3 which comprises part of the charge control programmer P-l.

FIG. 3 is a profile view of a cam 1-2 which comprises another part of the charge control programmer P-l.

FIG. 4 shows a profile view of a cam 2-3 which comprises part of the shut down programmer P-2.

FIG. 5 shows a profile view of a cam 2-2 which comprises another part of the shut down programmer P-2.

FIG. 6 is a timing diagram for the shut down programmer P-l which shows the relative open and closed times of switch SW6 and switch SW7 on the programmer P-l.

FIG. 7 is a timing diagram for the charge control programmer P-2 showing the relative open and closed times of switches SW3 and SW5 on the programmer P-2.

DETAILED SPECIFICATION Referring to the drawing there is shown in FIG. 1A, a typical incinerator I for burning waste and/or refuse or the like. It comprises a furnacearea F into which the refuse or waste is charged for burning. Access to the furnace is afforded through a charging door D which is operatively connected to an actuating means 2 for effecting its opening or closing. The actuating means 2 may comprise a piston and cylinder assembly, an electric motor or other suitable operator which is actuated by a switch means 1 located on a floor mat M located adjacent the charging door, and which switch means 1 is actuated by the weight of an operator standing on the charging mat; as will be hereinafter described. The incinerator I also includes an ash clean-out door A adjacent the bottom of the furnace through which the ash pit may be cleaned out. As will be hereinafter described the ash door A is operatively associated with a portion of the control system to prohibit operation of the incinerator unless the ashes are periodically cleaned out of the ash pit.

Burnable refuse is manually loaded into the incinerator I by an operator who is required to step onto a mat M located on the floor just in front of the incinerators charging door D. The floor mat M includes a microswitch SW1 (FIG. 1), actuated by the weight of the operator, which in turn delivers electrical energy to the charging door actuator 2 comprising an electro-pneumatic or other suitable actuator for opening or closing the charging door D. When an operator steps on the mat M, the micro-switch SW1 is closed, and thus completes an electrical circuit through appropriate

electrical leads

3, 4, 5 to the door actuator 2. Located in the circuit also are switches, SW5, and SW6 which are normally closed at the start of the loading cycle and which will be explained later. By completion of the foregoing circuit to the door actuator 2 the charging door D opens to permit insertion of refuse. When power to the charging door actuator 2 ceases, the door, being self-closing, returns by itself to a closed position.

An overcharge protection circuit is provided and it is rendered operative when the operator first steps on the mat M. Closure of the mats micro-switch SW1 by the operators weight energizes, through

appropriate leads

6, 7 from a 24 volt source 8, an enabling relay R5 which closes its normally open contacts 23. Contacts 23 when closed complete an electrical circuit from a 115 volt source 9, through

other leads

10, 21, l9, 18 to a first starting solenoid S1. Starting solenoid Sl completes a separate circuit through its own normally open contacts 14, which are now closed, and through

electrical leads

15, 16, 17, l8, 19, 22, to deliver 115 volt power to a drive motor 31 that turns an overcharge programmer P1. The overcharge programmer Pl commences turning for a single cycle time period, e. g., for 4 minutes and 30 seconds. During this time the operator is enabled to insert refuse for a cumulative total of seconds, and then he is required to wait for 3 additional minutes before any further loading.

Control of the programmer P1 as well as the loading and subsequent waiting periods is afforded by a cluster of three cams 1-1, 1-2, 1-3 which are mounted on a common shaft 30 that is turned by the programmer motor 31.

One of the three cams is a cycling cam I-l which is provided specifically for controlling the programmer Pl itself. The startingsolenoid S1 is of the latching type. Therefore, once it is energized, its relay contacts 14 remain closed even after electrical power to the solenoid S1 is interrupted. But the cycling cam l-l mechanically opens the contacts 14 of the starting solenoid S1 when the programmer P1 has completed its cycle by turning through an angular displacement of 360. With the electrical energy to the programmer motor 31 thus interrupted, the programmer P1 stops.

A charging control cam l-3, the rotation of which is identical in time and duration with the cycling cam l-l governs the duration of the loading and waiting periods of the incinerator. FIG. 2 shows the profile of the charge control cam 1-3 which has an indented or notched portion 32 of angular degrees and a raised portion 33 of 240 angular width. The speed of the programmer motor 31 is such that the cam cluster requires a predetermined elapsed time to turn through the first 120 and an additional predetermined lapsed time to turn through the remaining 230. In the illustrated embodiment a complete cycle of 360 is set so as to require a total elapsed time of 4 minutes and 30 seconds. 90 seconds for the first 120 and 3 minutes for the other 240. Referring again to FIG. 1, it may be seen that there is a normally open charging switch SW6 in the electrical circuit to the charging doors power pack or actuator 2. This switch SW6 is mechanically moved between its open and closed positions by the charging control cam 1-3. When the programmer P1 is at rest, prior to beginning a loading cycle, the charging switch SW6 rests on the raised portion 33 of the charging cam 1-3, at the spot designated by the arrow A1 in FIG. 2. As the programmer motor 31 begins to turn the cam 1-3 in the clockwise direction, due to the operators having initially stepped on the floor mat M, the indented portion 32 of the charging cam l-3 comes under the switch SW6. This causes contact 34 to close. In FIG. 1, it may be seen that this completes the electrical circuit from the 24 volt source 8 to the charging door actuator 2 causing the charging door to open. Unless otherwise interrupted, the programmer Pl will continue turning and 90 seconds later, the raised portion 33 of the cam 1-3 will come under the charging switch SW6 causing it to open its contacts 34. Upon being opening, the charging switch SW6 interrupts the electrical energy to the charging door actuator 2 and the door will close to begin the 3 minute waiting period. Should the operator step on the floor mat again during the 90 second loading period, the charging door will reopen. During the subsequent waiting period of 3 minutes, however, the charge control cam 1-3 will turn through its remaining 240 of angular displacement, and keep the charging switch SW6 open. Because the charging switch SW6 is now interrupting the circuit to the actuator 2 no amount of stepping on the floor mat can cause the charging door to re-open.

A safety cam 1-2 provides protection for the operator, should he happen to be on the floor mat M in the act of loading refuse when the end of the 90 second loading period occurs and the charging door is ready to close. FIG. 3 illustrates the profile of the safety cam 1-2. With a raised portion 34 of approximately 352.8 angular width and an indented portion 35 of 7.2", the cam 1-2 is able to mechanically open and close a safety switch SW7 (See FIG. 1) which rides on the cam 1-2. In FIG. 3, an arrow Bl shows where on the cam 1-2 the safety switch SW7 rests at the start of the loading cycle. This safety switch SW7, acting in conjunction with the floor mats micro-switch SW1 stops the charge programmer Pl before it calls for the charging-door D to close. The charging door D is thereby prevented from closing until the operator gets off the mat and the proglrammer Pl allowed to resume turning through its cyc e.

This safety precaution is made possible by the relative timings of the safety cam 1-2 and the charging control cam 1-3 and by a safety relay R4. The safety relay R4 is controlled by the safety cam l-2 and in turn controls normally closed contacts 36 in the electrical circuit that drives the programmer P1. The configuration of the safety cam l-2 is designed to close the safety switch SW7 after the programmer P1 has turned for an elapsed time of say 87.3 seconds following the commencement of the loading cycle. This timing is intended to occur before the charging control cam l-3 can terminate the 90 second loading cycle.

FIG. 6 is a timing diagram showing when the two cams 1-2, 1-3 open and close their respective switches SW6, SW7. The closing of the safety switch SW7 energizes the safety relay R4 through leads 10, 18, 20, 21 by connecting it with the 115 volt power source 9. By opening its contacts 36 the safety relay R4 interrupts the electrical power to the programmers motor 31. The result is to stop the programmer P1 2.7 seconds before the charge control cam 1-3 can open the charging switch SW6. The end of the 90 second loading cycle is, therefore, not reached. Since the charging switch SW6 does not interrupt the power to the charging door actuator 2 the charging door D does not close.

However, when the man gets off the mat, the microswitch SW1 opens and the enabling relay R5 de-energizes and opens its contacts 23. The circuit to the safety relay R4 is also opened, and R4 de-energizes, thus allowing its contacts 36 to close. With the circuit to the programmer motor 31 thus restored, the programmer P1 will resume turning for the balance of its cycle.

The control system further contemplates rendering the incinerator inoperative to accept further refuse or waste after a predetermined period of operation, eg 24 hours. This feature is provided so as to insure that an operator will clean out the ash pit to effect removal of the ash to insure optimum incinerator operation.

This is attained by including in the circuit (FIG. 1) a timer, e.g., a 24-hour clock T1. The timer T1 is a continuously running clock which will emit an electrical impulse of a predetermined duration, e. g., 12 minutes or another suitable period. This impulse is utilized to start a shut down programmer P2 which prohibits any further loading of additional refuse into the incinerator. Subsequent start up will occur only if ashes are removed, and a predetermined time interval is provided to effect the ash removal. Generally 30 minutes has been found to be sufficient time to effect this ash removal. Through appropriate electrical leads 40, 41, the 12 minute pulse is delivered to a second starting solenoid S2 which, by closing its contacts 43, permits the energizing of a shut down programmer motor 44. The programmer motor 44 is powered from a volt source 9 through separate

electrical leads

45, 46, 47. In the motor circuit are certain other series connected

relay contacts

70, 52. Since these

other contacts

70, 52 are normally closed, they do not interfere with the starting of the programmer P2 when the shut down cycle is initiated.

Additional loading of refuse is prohibited by rendering the door actuator 2 inoperative. Programmer P2 accomplishes this. As previously described, the charging door actuator 2 receives electricity from a 24 volt source 8 through its

electrical leads

3, 4, 5, 48, 49. In this circuit is a single pole double throw electrical switch SW5 that is mechanically transferable between its two alternate positions by a shut down cam 2-3. This cam is one of three cams mounted on a common shaft 50 this is turned by the shut down programmers motor 44. When the programmer P2 is at rest, and at the beginning of its cycle, the transfer switch SW5 is normally closed to make a complete circuit to deliver 24 volt power to the charging doors opening mechanism. The circuit is made by

electrical leads

3, 4, 5, 48, 49 which connect the transfer switch SW5 and the microswitch SW1 in series with the actuator 2. After the programmer P2 has started and has turned through say, 5l.5 of its total rotation, the transfer switch SW5 is transferred by the shut down cam 1-3 to close its normally open contact, and the electrical supply to the actuator 2 is interrupted. With no power supply, the charging door D closes and remains closed to prohibit any further loading.

In its transferred position the transfer switch SW5 also stops the programmer P2 and confers on the incinerators ash door A subsequent control of the programmer P2. Through leads 53, 51 which previously carried no electricity, the transfer switch SW5 now connects an ash door relay R1 to the 24 volt source 8 of power. The contact 52 of this relay R1 are normally closed and although they are in the circuit that powers the programmer P2 they do not at first interfere therewith. Upon the energizing of the ash door relay R1, however, these contacts 52 open and stop the programmer P2 by interrupting its electrical supply. A micro-switch SW2, operated by the ash door is connected by its

own leads

55, 54 to bridge the normally closed contacts 52 of the ash door relay R1. Therefore, even though the ash door relay contacts 52 have been opened by the action of the transfer switch SW5, they can be short circuited by the ash door micro-switch SW2. The ash door micro-switch SW2 is ordinarily open when the ash door is in a closed condition but closes to complete the programmer motor circuit when the ash door is opened. Thus, once the ash door relay R1 opens its contacts 52, the programmer P2 stops and will advance in its cycle only if the ash door is kept open.

The ash removal is monitored by the shut down cam 2-3. In the illustrated embodiment of the invention this cam is designed to provide a minute preparation period followed by a 30 minute shut down period. FIG. 4 shows the profile of the shut down cam 2-3 and the arrow C1 indicates the point of the cam 2-3 on which the transfer switch SW5 rests at the beginning of the shut down cycle. The cam 2-3 has an indented portion 60 of 5 angular width. While this indented portion 60 is under the transfer switch SW5, the transfer switch SW5 is in its normal position. In this position it electrically connects certain leads 48, 49 in order not to interfere with the electrical circuit to the charging door actuator 2. However, the switch SW5 is transferred when an unindented portion 61 comes under it and thereby disables the power pack circuit.

Upon being started by the aforesaid 12 minute pulse, the programmer P2 requires 5 minutes to turn the shut down cam 2-3 through the indented portion 60 of its periphery. This 5 minute period provide a protection for the incinerator operator should he happen to be in the act of loading refuse at the time the shut down cycle begins. At the end of the initial 5 minute period the unindented portion 61 of the shut down cam 2-3 comes under the transfer switch SW5 thus causing it to transfer its contacts and thereby to commence the actual shut down of the incinerator.

The ash door must be kept open for a cumulative total of at least minutes. This is because 30 minutes are required for the shut down programmer P2 to finish turning the shut down 2-3 through the balance of the ash removal cycle. After the cam 2-3 has been turned for a total period of minutes, the indented portion 60 of the cams periphery will again come under the transfer switch SW5 and cause the contacts to retransfer back to their original position. In this way, the circuit through the transfer switch SW5 to the charging door actuator 2 is again completed and the charging door D may be reopened for loading.

This same re-transfer, simultaneously deprives the ash door A of its control over the incinerator. The circuit to the ash door relay R1 through its lead 53 is broken and its contacts 52 return to their normally closed condition. With the electrical circuit'through its leads 62, 63 restored, the shut down programmers operation no longer depends on the open or closed condition of the ash door.

With the completion of the shut down cycle and resumption of charging door D operations the pro grammer P2 is required to come to a stop. The purpose is so that the programmer P2 will be ready for the next shut down cycle 24 hours later. The programmer control cam 2-1 (not shown separately) automatically stops the programmer P2 by mechanically unlatching the starting solenoid S2 contacts 43 when the cam cluster has been turned by the programmer motor 44 a total of 360. With its electrical supply interrupted the motor 44 can no longer turn the shut down programmer P2.

A protective feature is required for the operator, should he happen to be standing on the loading mat M, when actual shutdown is about to occur. The automatic closing of the charging door D is prevented by a safety cam 2-2, shown in FIG. 5, which is mounted on the programmers shaft 50 along with the shut down cam 2-3 and is rotated at the same time and at the same speed. A safety switch SW3 is mechanically operated by the safety cam 2-2. This switch SW3 is placed in the circuit 10, ll, 12, 71 of a safety relay R2 which has normally closed contacts 70. Through appropriate leads 13, 71, 12, 11, 10 closure of the safety switch SW3 by the safety cam 2-2 delivers 1 15 volt power to the safety relay R2 which then opens its own contacts 70. These contacts are in the power circuit to the shut down programmer P2 and, by opening, will cause the programmer motor 44 to stop. An arrow D1 in FIG. 5 shows the spot on the safety cam 2-2 on which the safety switch SW3 rests at the beginning of the shut down cycle. The cam 2-2 has an indented portion 73 that is of 72 angular width and which is located on the periphery of the cam where it will come under the safety switch 4 minutes and 29 seconds after the programmer P2 has begun turning through the shut down cycle. The significance of this timing may be better understood by referring to FIG. 7 which is a diagram showing the relative times of operation of the shut down switch SW5 and the safety switch SW3. The contacts of the safety switch SW3 are normally open but they close when the indented portion 73 of the safety cam 2-2 passes under the safety switch SW3. This event occurs earlier than the transfer of the shut down switch SW5 which is scheduled to operate at 'the end of 5 minutes after the shut down programmer P2 starts turning. An operator, standing on the mat M, closes the micro-switch SW1 and energizes the enabling relay R5 thereby closing its contacts 23. With a circuit this completed through connecting leads 11, 12, volt power is supplied through the now closed safety switch SW3 to energize the safety relay R2. Upon being energized the safety relay R2 opens its normally closed contacts 70 to break the circuit to the programmer P2. With the power shut off, the programmer P2 stops and the shut down cycle may not continue until the operator gets ofi' the mat.

It will be understood that the time intervals herein set forth are merely illustrative as they can be changed by altering the shape of the cams accordingly.

While the instant invention has been described with respect to a particular embodiment thereof it will be readily understood and appreciated that variations and modifications may be made without departing from the spirit or scope of the invention.

What is claimed is:

1. In combination, a combustion chamber having a charging door and an ash removal door, and

a control means including an actuator for effecting the operation of said charging door,

switch means connected in circuit with said actuator located adjacent said charging door adapted to be activated by the weight of an operator when charging said chamber,

a programmer operatively connected to said switch means and door actuator to render said actuator operative for a predetermined time interval in response to the actuation of said switch means and to render said actuator inoperative for a predetermined time interval upon the closing of said charging door upon the lapse of said operative interval of time.

2. The invention as defined in claim 1 and including a safety interlock means to prohibit the closing of said charging door in the event said switch means is maintained activated at the lapse of said operative interval of time.

3. The invention as defined in claim 2 and including a second programmer means operatively associated with said ash door and said charging door to measure the elapsed time since the last previous opening of the ash door.

4. The invention as defined in claim 3 wherein said latter means emit a signal upon sensing said predetermined lapsed time since the last previous opening of the ash door,

and means responsive to said signal to prohibit the opening of said charging door for a predetermined time interval necessary to effect ash clean out.

5. The invention as defined in claim 4 and including a second interlock safety means to stop the run down of said second programmer means if an operator is in the act of charging said chamber at the end of said elapsed time since the last previous opening of the ash door.

6. The invention as defined in claim 1 wherein said switch means includes a mat located in front of the charging door, and said mat including a switch for activating said door actuator during run down of said programmer means during said operative time interval.

7. The invention as defined in claim 4 and including means to restore the opening of said charging door,

said restoration means being controlled by the opening and closing of said ash door.

8. In combination, a combustion chamber having a charging door and an ash clean-out door, and

an actuator for opening and closing said charging door,

an overcharge protection circuit operatively connected to said door actuator,

said overcharge protection circuit including a switch means actuated by the weight of an operator,

a programmer means including a starting means that is actuated when said switch means is actuated,

said programmer means including means for rendering said actuator operative for a predetermined charging time interval each time said switch means is activated during said charging interval,

and said programmer including means for rendering said door actuator inoperative for a predetermined non charging time interval upon the lapsing of said charging time interval.

9. The invention as defined in claim 8 wherein said programmer means includes:

a safety interlock means to maintain said charging door in the open position in the event said operator is activating said switch means at the end of said charging time interval. I

10. The invention as defined in claim 8 and including an ash monitor means.

1 l. The invention as defined in claim 1 1 wherein said ash monitor means includes:

a timing means to measure the elapsed time since the last previous opening of the ash removal door,

said timing means emitting a signal upon sensing said elapsed time since the last previous ash cleaning,

and means responsive to said signal to prohibit the opening of said charging door to prevent further charging of the combustion chamberv until the ashes have been removed.

12; The invention as defined in claim 11 and including means to restore the opening of the charging door upon the removal of the ashes; said restoration means being controlled by the opening and closing of said ash door.

13. The invention as defined in claim 11 wherein said latter means includes a shut-down programmer including means to stop the run down of said shut-down-programmer in the event an operator is charging said chamber with the charging door in the open position.

14. A system for monitoring ash accumulation in an incinerator, having an ash removal door and a charging door, comprising:

means to emit a shut-down signal at periodic time intervals,

means responsive to said signal to disable opening of the charging door,

means to record the length of each time the ash door remains in an open position during said periodic time interval,

means for accumulating successive periods of ash door open time where said open time is interrupted one or more times by closing of the ash door,

means for emitting a restoring signal when ash door open times accumulate to a predetermined quantum of time, and

means responsive to said restoring signal to restore operation of the charging door.

15. A safety system to provide a limited charging time followed by a mandatory waiting period of predetermined duration during. which charging is prohibited in an incinerator have a closable charging door comprising:

actuating means for moving said charging door between its open and closed positions,

an electric circuit including a first source of electrical power,

a switch means disposed in said circuit so as to be actuated by an operator who is charging said incinerator with refuse,

a charging programmer having a shaft and an electric motor driving the shaft at a predetermined angular speed, charging cam mounted on said shaft to rotate therewith, and having a peripheral surface containing an indent of constant radius and of predetermined angular width, and a raised portion of constant radius and predetermined angular width,

a charging electrical switch riding on the periohery of said charging cam wheel so that the switch'is closed when it rides on the indent and is open when it rides on the raised portion of the cam wheel whereby the beginning of the indent is initially under the charging switch,

said micro-switch, actuator, and the charging switch being connected in series in said circuit,

a second power source,

a latching type electrical switch,

a solenoid adapted to close said latching switch when the solenoid is energized, whereupon said latching switch will latch in a closed position regardless of loss of power to the solenoid,

an enabling relay having a single pair of normally open electrical contacts,

electrical leads connecting the enabling relay in series with the micro-switch in the low voltage circuit, but in parallel with the series combination of actuating means and cam-operated charging switch,

said latching contacts and the electric motor being connected in series with said second source of power, and

said enabling contact and the starting solenoid being connected in series with said second source of power,

a cycling cam mounted on the shaft to turn with the charging cam wheel, and adapted to mechanically unlatch the contacts of the starting solenoid to open the contacts after the shaft has made one complete revolution.

16. In the incinerator safety system of claim 15 including means to delay the start of the non-charging period, if an operator is inserting refuse at the termination of the charging period,

said delay means including:

a safety cam mounted on the programmer shaft to turn with the cycling cam and the charging cam, and having a peripheral surface containing an indent of constant radius of predetermined angular width, and having an unindented portion of constant radius-and predetermined angular width,

a safety switch riding on the periphery of the safety cam and mounted so that the safety cams indent mechanically moves the switch into its closed position not more than a few seconds after the programmer motor begins to turn through its cycle, and to open position not less than a few seconds after the programmer begins to turn through its cycle,

a safety relay having a normally closed pair of contacts,

electrical leads connecting the safety switch and the safety relay in series with the second power source, and

electrical leads connecting the normally closed contacts of the safety relay, the latching contacts and the programmer motor in series with said second source of power, so that when the safety cam opens the safety switch, the second source of power is interrupted and the programmer motor stops in its cycle, until the incinerator attendant allows the micro-switch to open.

17. A system for monitoring ash accumulation in an incinerator having a charging door for charging, comprising:

an actuator for moving the charging door between its open and closed positions, a source of low voltage electrical power, e.g., 24

volts,

a mat switch means disposed as to be closed by an incinerator attendant during charging of the incinerator with refuse,

a shut down programmer having a motor shaft adapted to make one revolution in a predetermined time interval,

a shut down cam mounted on the shaft and having a peripheral surface with an indent of contant radius and predetermined angular width and a remaining unindented portion of constant radius,

a transfer switch having normally closed contacts and normally open contacts riding on the periphery of the shut down cam so that the normally closed contacts of the switch are closed when the indent is under the switch and open when the unindented portion is under the switch, said transfer switch being disposed so that at the beginning of the shut down cycle the indent portion of the cam comes under the switch,

electrical leads connecting the charging door, actuator, the mat switch, and the normally closed contacts of the transfer switch in series with the low voltage power source,

a high voltagesource of electrical power, e.g.,

volts,

an electrical clock timer adapted to be driven by the 1 15 volt power source, and having electrical output terminals at which thereis available periodically an electrical voltage pulse of predetermined duration, said pulse occurring at the expiration of each successive 24 hours following the commencement of the most recent previous pulse,

a second starting solenoid having normally open contacts which are adapted to latch in a closed position when electrical power is supplied to the solenoid, said solenoid being capable of closing its contacts in a latched position in response to the electrical pulse from the timer,

electrical leads connecting the second starting solenoid to the output terminals of the timer,

electrical leads connecting in series, the programmer motor, the normally open solenoid contact and the second power source, and

a cycling cam mounted on the programmer shaft to turn integrally with the shut down cam, and adapted to mechanically unlatch the contacts of the starting solenoid to open the contacts after the shaft has made one complete revolution.

18. In an incinerator having a control system for monitoring ash accumulation as defined in claim 17 including an ash door,

an ash door switch disposed as to be held in a closed position by the ash door when the ash door is open, and in open circuit position when the ash door is shut,

an ash door relay having normally closed electrical contacts,

electrical leads connecting the ash door relay, the 24 volt power source and the normally open contacts of the transfer switch all in series relation,

electrical leads connecting the normally closed contacts of the ash door relay in series relation with the series combination of programmer motor, normally open solenoid contact, and 115 volt power source, and electrical leads connecting the ash door micro-switch in parallel relation with the normally closed contacts of the ash door relay.

19. In an incinerator having a control system for monitoring ash accumulation defined in claim 17 and including:

a personnel safety interlock comprising: a safety relay having normally open electrical contacts,

a safety cam mounted on the shut down programmer's shaft to turn at the same angular speed and in the same direction of rotation as the shut down cam, said safety cam having a peripheral serface with an indent of a predetermined width and constant radius, and a remaining unindented portion,

a normally open safety switch disposed as to be mechanically movable between its open and closed positions by the indent and unindented portions of the safety cam, said safety switch being disposed as to be closed when the indent comes under the switch at a predetermined interval after the programmer has commenced turning through 1 electrical leads connecting the normally open contacts of the enabling relay in series relation with the series combination of the cam operated safety switch, the volt power source, and the safety relay.

Claims

1. In combination, a combustion chamber having a charging door and an ash removal door, and a control means including an actuator for effecting the operation of said charging door, switch means connected in circuit with said actuator located adjacent said charging door adapted to be activated by the weight of an operator when charging said chamber, a programmer operatively connected to said switch means and door actuator to render said actuator operative for a predetermined time interval in response to the actuation of said switch means and to render said actuator inoperative for a predetermined time interval upon the closing of said charging door upon the lapse of said operative interval of time.

4. The invention as defined in claim 3 wherein said latter means emit a signal upon sensing said predetermined lapsed time since the last previous opening of the ash door, and means responsive to said signal to prohibit the opening of said charging door for a predetermined time interval necessary to effect ash clean out.

7. The invention as defined in claim 4 and including means to restore the opening of said charging door, said restoration means being controlled by the opening and closing of said ash door.

8. In combination, a combustion chamber having a charging door and an ash clean-out door, and an actuator for opening and closing said charging door, an overcharge protection circuit operatively connected to said door actuator, said overcharge protection circuit including a switch means actuated by the weight of an operator, a programmer means including a starting means that is actuated when said switch means is actuated, said programmer means including means for rendering said actuator operative for a predetermined charging time interval each time said switch means is activated during said charging interval, and said programmer including means for rendering said door actuator inoperative for a predetermined non charging time interval upon the lapsing of said charging time interval.

9. The invention as defined in claim 8 wherein said programmer means includes: a safety interlock means to maintain said charging door in the open position in the event said operator is activating said switch means at the end of said charging time interval.

10. The invention as defined in claim 8 and including an ash monitor means.

11. The invention as defined in claim 11 wherein said ash monitor means includes: a timing means to measure the elapsed time since the last previous opening of the ash removal door, said timing means emitting a signal upon sensing said elapsed time since the last previous ash cleaning, and means responsive to said signal to prohibit the opening of said charging door to prevent further charging of the combustion chamber unTil the ashes have been removed.

12. The invention as defined in claim 11 and including means to restore the opening of the charging door upon the removal of the ashes; said restoration means being controlled by the opening and closing of said ash door.

14. A system for monitoring ash accumulation in an incinerator, having an ash removal door and a charging door, comprising: means to emit a shut-down signal at periodic time intervals, means responsive to said signal to disable opening of the charging door, means to record the length of each time the ash door remains in an open position during said periodic time interval, means for accumulating successive periods of ash door open time where said open time is interrupted one or more times by closing of the ash door, means for emitting a restoring signal when ash door open times accumulate to a predetermined quantum of time, and means responsive to said restoring signal to restore operation of the charging door.

15. A safety system to provide a limited charging time followed by a mandatory waiting period of predetermined duration during which charging is prohibited in an incinerator have a closable charging door comprising: actuating means for moving said charging door between its open and closed positions, an electric circuit including a first source of electrical power, a switch means disposed in said circuit so as to be actuated by an operator who is charging said incinerator with refuse, a charging programmer having a shaft and an electric motor driving the shaft at a predetermined angular speed, a charging cam mounted on said shaft to rotate therewith, and having a peripheral surface containing an indent of constant radius and of predetermined angular width, and a raised portion of constant radius and predetermined angular width, a charging electrical switch riding on the periohery of said charging cam wheel so that the switch is closed when it rides on the indent and is open when it rides on the raised portion of the cam wheel whereby the beginning of the indent is initially under the charging switch, said micro-switch, actuator, and the charging switch being connected in series in said circuit, a second power source, a latching type electrical switch, a solenoid adapted to close said latching switch when the solenoid is energized, whereupon said latching switch will latch in a closed position regardless of loss of power to the solenoid, an enabling relay having a single pair of normally open electrical contacts, electrical leads connecting the enabling relay in series with the micro-switch in the low voltage circuit, but in parallel with the series combination of actuating means and cam-operated charging switch, said latching contacts and the electric motor being connected in series with said second source of power, and said enabling contact and the starting solenoid being connected in series with said second source of power, a cycling cam mounted on the shaft to turn with the charging cam wheel, and adapted to mechanically unlatch the contacts of the starting solenoid to open the contacts after the shaft has made one complete revolution.

16. In the incinerator safety system of claim 15 including means to delay the start of the non-charging period, if an operator is inserting refuse at the termination of the charging period, said delay means including: a safety cam mounted on the programmer shaft to turn with the cycling cam and the charging cam, and having a peripheral surface containing an indent of constant radius of predetermined angular width, and having an unindented portion of constant radius and predetermined angular width, a safety switch riding on the periphery of the safety cam and mounted so that the safety cam''s indent mechanically moves the switch into its closed position not more than a few seconds after the programmer motor begins to turn through its cycle, and to open position not less than a few seconds after the programmer begins to turn through its cycle, a safety relay having a normally closed pair of contacts, electrical leads connecting the safety switch and the safety relay in series with the second power source, and electrical leads connecting the normally closed contacts of the safety relay, the latching contacts and the programmer motor in series with said second source of power, so that when the safety cam opens the safety switch, the second source of power is interrupted and the programmer motor stops in its cycle, until the incinerator attendant allows the micro-switch to open.

17. A system for monitoring ash accumulation in an incinerator having a charging door for charging, comprising: an actuator for moving the charging door between its open and closed positions, a source of low voltage electrical power, e.g., 24 volts, a mat switch means disposed as to be closed by an incinerator attendant during charging of the incinerator with refuse, a shut down programmer having a motor shaft adapted to make one revolution in a predetermined time interval, a shut down cam mounted on the shaft and having a peripheral surface with an indent of contant radius and predetermined angular width and a remaining unindented portion of constant radius, a transfer switch having normally closed contacts and normally open contacts riding on the periphery of the shut down cam so that the normally closed contacts of the switch are closed when the indent is under the switch and open when the unindented portion is under the switch, said transfer switch being disposed so that at the beginning of the shut down cycle the indent portion of the cam comes under the switch, electrical leads connecting the charging door, actuator, the mat switch, and the normally closed contacts of the transfer switch in series with the low voltage power source, a high voltage source of electrical power, e.g., 115 volts, an electrical clock timer adapted to be driven by the 115 volt power source, and having electrical output terminals at which there is available periodically an electrical voltage pulse of predetermined duration, said pulse occurring at the expiration of each successive 24 hours following the commencement of the most recent previous pulse, a second starting solenoid having normally open contacts which are adapted to latch in a closed position when electrical power is supplied to the solenoid, said solenoid being capable of closing its contacts in a latched position in response to the electrical pulse from the timer, electrical leads connecting the second starting solenoid to the output terminals of the timer, electrical leads connecting in series, the programmer motor, the normally open solenoid contact and the second power source, and a cycling cam mounted on the programmer shaft to turn integrally with the shut down cam, and adapted to mechanically unlatch the contacts of the starting solenoid to open the contacts after the shaft has made one complete revolution.

18. In an incinerator having a control system for monitoring ash accumulation as defined in claim 17 including an ash door, an ash door switch disposed as to be held in a closed position by the ash door when the ash door is open, and in open circuit position when the ash door is shut, an ash door relay having normally closed electrical contacts, electrical leads connecting the ash door relay, the 24 volt power source and the normally open contacts of the transfer switch all in series relation, electrical leads connecting the normally closed contacts of the ash door relay in series relation with the series combInation of programmer motor, normally open solenoid contact, and 115 volt power source, and electrical leads connecting the ash door micro-switch in parallel relation with the normally closed contacts of the ash door relay.

19. In an incinerator having a control system for monitoring ash accumulation defined in claim 17 and including: a personnel safety interlock comprising: a safety relay having normally open electrical contacts, a safety cam mounted on the shut down programmer''s shaft to turn at the same angular speed and in the same direction of rotation as the shut down cam, said safety cam having a peripheral serface with an indent of a predetermined width and constant radius, and a remaining unindented portion, a normally open safety switch disposed as to be mechanically movable between its open and closed positions by the indent and unindented portions of the safety cam, said safety switch being disposed as to be closed when the indent comes under the switch at a predetermined interval after the programmer has commenced turning through its shut down cycle, an enabling relay having normally open electrical contacts, electrical leads connecting the enabling relay in series relation with the ash door micro-switch, the safety switch and the low voltage power source, and electrical leads connecting the normally open contacts of the enabling relay in series relation with the series combination of the cam operated safety switch, the 115 volt power source, and the safety relay.