PROCESS FOR THE CREMATION OF ANIMAL REMAINS

Abstract

A process for cremation of animal remains includes the steps of inserting animal remains into a primary combustion chamber of a cremator and igniting a primary burner in the primary combustion chamber. An oxygen content of gas leaving the primary combustion chamber is measured. The oxygen content is represented by an oxygen level information signal. A temperature of the primary combustion chamber is also measured and the temperature measured is represented by a primary temperature signal. Volatilization of animal remains is determined dependent upon at least one of the oxygen level information signal, the primary temperature signal and the passage of a predetermined amount of time. Upon determining volatilization of the animal remains, a volumetric flow rate of gas or fuel fed into the primary burner is adjusted. Further, the quantity of air being introduced into the primary combustion chamber is adjusted dependent upon the oxygen level information signal.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a process for the cremation of animal remains.

2. Description of the Related Art

The cremation of human and/or animal remains is a method for final disposition of a body which has been known for thousands of years. More specifically, cremation is the use of high-temperature burning, vaporization and oxidation to reduce dead animal bodies, including humans, to basic chemical compounds, such as gases and mineral fragments. With the passage of time, primitive methods have evolved with the development of modern technology. A modern crematory utilizes an industrial furnace capable of generating temperatures sufficient to ensure disintegration of a corpse. Cremation devices or cremators are known in the art which utilize a process dependent upon temperature alone to control the combustion of remains. Processes that utilize monitoring of temperature alone are not fuel efficient as there is no mechanism for detecting volatilization or combustion of the remains. Accordingly, the principal burner in such a device continues to operate after combustion of the remains has begun.

What is needed in the art is a more efficient process for effectively and substantially completely cremating animal remains.

SUMMARY OF THE INVENTION

The present invention provides a process for the cremation of an animal remains. For purposes of the present invention, the phrase “animal remains” or the word “remains” shall include the remains of any animal as well as human remains and, for example, human tissue such as an amputated limb. The process according to the present invention includes the steps of inserting the animal remains into a primary combustion chamber of a cremation device and igniting a primary burner, for example positioned directly over the body, in the primary combustion chamber. An oxygen content of a gas leaving the primary combustion chamber is measured, for example using a zirconia oxygen sensor, the oxygen content being represented by an oxygen level information signal which is input into a control system. The temperature of the primary combustion chamber is measured, for example utilizing a thermocouple positioned in the primary combustion chamber. The temperature measured is represented by a primary temperature signal which is input into the control system. Volatilization of the animal remains is determined based on at least one of the passage of a predetermined amount of time, the differential of the oxygen level information signal from a starting or set point and the primary temperature signal. If volatilization of the animal remains has occurred, then the primary burner is adjusted, for example diminished or extinguished entirely. A continued burn of the animal remains is ensured by adjustment of a quantity of air being introduced through an air input valve in the primary combustion chamber which is differentially controlled by a cascade control loop circuit, which is for example part of a proportional-integral-derivative (PID) control system.

According to an additional embodiment, the process according to the present invention includes the steps of inserting animal remains into a primary combustion chamber of a cremation device, igniting a primary burner in the primary combustion chamber, and sensing volatilization of the animal remains using a sensor. After sensing volatilization of the remains, the volumetric flow rate of a gas or fuel to the primary burner is reduced and a volumetric flow rate of air into the primary combustion chamber is adjusted.

Advantageously, the process of the present invention allows for effective management of the cremation of larger, more volatile animal remains. For such larger, more difficult cases, a much higher level of available fuel in the form of tissue and fatty materials can, without operator interface, get out of control when the cremation device is operated based on temperature alone. By reducing the air input in such cases, in reaction to the higher temperatures, the control loop will automatically allow the air flow (and thus available oxygen) to be reduced, thus starving the burning remains (or corpse) of necessary oxygen and, in doing so, reduce the volatilization.

Another advantage of the present invention is that the amount of fuel utilized by the furnace, for example in the form of fossil fuels, propane, natural gas or wood, is reduced since the fuel provided to the primary burner upon sensing volatilization of the remains is reduced, if not completely cut off.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a side view of a cremator arranged for carrying out an embodiment of a process according to the present invention;

FIG. 2 is an end view of the cremator of FIG. 1;

FIG. 3 is a flow chart of an embodiment of a process for cremating animal remains using the cremator of FIGS. 1 and 2; and

FIG. 4 is a schematic illustration of an embodiment of a control system that uses the process of FIG. 3.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one embodiment of the invention and such exemplification is not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and more particularly to FIGS. 1-4, there is shown an embodiment of a cremator 10 which generally includes a primary combustion chamber 12 and a secondary afterburner chamber 14, for example positioned below primary combustion chamber 12. A primary burner 16 is positioned in primary combustion chamber 12, for example above where the animal remains 18 are positioned upon insertion into the chamber. A sensor 20, for example a zirconia oxygen sensor 20, is positioned in a breach area 22 between primary combustion chamber 12 and secondary afterburner chamber 14. Sensor 20 produces an oxygen level information signal and is in communication with a controller 24 (shown in FIG. 4) which repeatedly monitors the constant oxygen level information signal for input into a proportional-integral-derivative (PID) algorithm utilized to control an air flow control valve 26 that varies the air input into primary combustion chamber 12. Primary combustion chamber 12 includes a temperature sensor 28, for example in the form of a thermocouple, and secondary afterburner chamber 14 includes a temperature sensor 30, which may also be in the form of a thermocouple, in communication with a controller 24 (shown in FIG. 4). Temperature sensor 30 for secondary afterburner chamber 14 is on a separate and distinct loop or circuit, than that to which temperature sensor 28 for primary combustion chamber 12 is connected. Secondary afterburner chamber 14 is in fluid connection with stack 32 through which exhaust fumes exit cremator 10.

Cremator 10 which is utilized in association with the process 34 of the present invention, includes an opacity sensor 36 connected to controller 24 (shown in FIG. 4). Opacity sensor 36 is positioned after secondary afterburner chamber 14 in stack 32. Opacity sensor 36 is configured to detect the amount of particulate material in exhaust fumes escaping from secondary afterburner chamber 14. If the level of particulate in the exhaust fumes exceeds a predetermined amount, controller 24 will be configured to shut primary burner 16 down while continuing to run an afterburner 38 positioned in secondary afterburner chamber 14 in order to effectively manage the level of particulate exiting stack 32.

Now additionally, FIG. 3 illustrates an embodiment of process 34 of the present invention. Animal remains 18, for example human remains 18, are inserted into primary combustion chamber 12 for cremation, as shown at step 40. The animal remains 18 may, for example, be contained in a cardboard and/or wooden container which will combust along with the remains contained therein. Primary burner 16, which may for example be positioned directly over animal remains 18 in primary combustion chamber 12, is ignited as illustrated at step 42. Upon the expiration of a predetermined period of time at step 44, in other words once animal remains 18 have been ignited by primary burner 16, the controller 24 will begin to control process 34. More specifically, a cascade control loop circuit 60 will be utilized, after the expiration of the predetermined period of time at step 44, to control the input of an airflow into primary combustion chamber 12. Cascade control loop circuit 60 includes a primary loop and a secondary loop. The primary loop is an air input control loop, while the secondary loop is a temperature control loop. The primary loop includes sensor 20, air flow valve 26 and controller 62. The secondary loop includes temperature sensor 28, primary burner 16 and controller 62. At step 46, sensor 20, for example zirconia oxygen sensor 20, senses an oxygen content of gas exiting primary combustion chamber 12 that is communicated to controller 24 in the form of an oxygen level information signal. This signal will be repeatedly monitored and factored into the PID control algorithm of primary loop for effective and efficient control of process 34. More specifically, cascade control loop circuit 60 causes air flow valve 26 in primary combustion chamber 12 to vary a volumetric flow of air through air flow valve 26 dependent upon the oxygen level information signal input into the primary loop. If at step 48 the oxygen content is not within a predefined range, then the oxygen level information signal which is part of primary loop is communicated to controller 24 to be used by controller 24 to cause an adjustment to the air flow into primary combustion chamber 12, as illustrated at step 50. Controller 24 will accordingly cause air flow control valve 26 to vary the volumetric flow of air into primary combustion chamber 12, bringing the air flow into stoichiometric balance with a quantity of free fuel available in the animal remains 18 and any fuel present in primary burner 16. If the oxygen content is within the predefined range at step 48, then no adjustment to the quantity of air flow into primary combustion chamber 12 is necessary. Generally, the oxygen content is in a range between approximately 7 and 12%, for example between 7 and 10%, or at approximately 7% to ensure combustion of the remains continues to substantial completion. If the oxygen content drops below, for example approximately 7%, then primary control loop will respond by raising the temperature within a predefined range in primary combustion chamber 12.

At the same time sensor 20 is measuring the oxygen content of gas exiting primary combustion chamber 12, temperature sensor 28 measures the temperature of primary combustion chamber 12 at step 52, the temperature measured being submitted to controller 24 in the form of a primary temperature signal. This signal will also be periodically sampled and input into the PID algorithm for effective and efficient control of process 40. If the temperature measured is not within the predefined range, then a determination is made as to whether the air flow to primary combustion chamber 12 and/or the fuel flow to primary burner 16 should be adjusted, as illustrated at step 56. Subsequently, the fuel flow to primary burner 16 may be adjusted at step 58. Controller 24 is also configured to adjust air flow into primary combustion chamber 12, dependent upon a predetermined temperature. At step 56, the determination to adjust air flow to primary combustion chamber 12 and/or fuel flow rate to primary burner 16, such considerations as the passage of a predetermined period of time, weight of animal remains 18 prior to insertion into primary combustion chamber 12, and a maximum predetermined temperature will be factored into the decision undertaken at step 56. Generally, the temperature of primary combustion chamber 12 should be maintained between approximately 1400 and 1600 degrees Fahrenheit. If at step 54, the measured temperature is within the predefined temperature range, for example between approximately 1400 and 1650 degrees Fahrenheit, then process 34 returns to step 52.

Controller 24 is also configured to factor variations of the temperature of primary combustion chamber 12 into the PID algorithm in adjusting the quantity of air flow into primary combustion chamber 12. For example, if the temperature of primary combustion chamber 12 were to exceed a certain predetermined maximum temperature, then controller 24 will adjust both the flow rate of fuel to primary burner 16 and the quantity of air flow into primary combustion chamber 12. Likewise, controller 24 can also factor into the PID algorithm variations of the oxygen content of gas exiting primary combustion chamber 12 in adjusting both the flow rate of fuel to primary burner 16 and the quantity of air flow into primary combustion chamber 12. For example, if the oxygen content of the gas exiting primary combustion chamber 12 exceeds a certain predetermined value, this is a sign that the combustion of remains 18 is slowing or stopped. In such a case, it may be necessary for the fuel to primary burner 16 to be increased or, if primary burner 16 was previously extinguished, to re-light primary burner 16, dependent upon how long the remains have been combusting. If the oxygen content of the gas exiting primary combustion chamber 12 exceeds that predetermined value and remains 18 have been combusting for a predetermined period of time, it is a sign that the combustion of remains 18 is complete or nearing completion, in which case, primary burner 16 may be extinguished if it has not already been extinguished. Accordingly, process 34 further includes the step of detecting an end of process 34 after the expiration of a predetermined period of time and the occurrence of an elevation of the oxygen content, for example above approximately 12%. In this case, the predetermined period of time would be determined dependent upon the weight of animal remains 18 prior to insertion into primary combustion chamber 12, the type of container in which they are enclosed or contained and an anticipated burn temperature range.

Now additionally, FIG. 4 illustrates in a schematic fashion a control system 66 for executing process 34 according to the present invention. Control system 66 includes controller 24 communicatively coupled with primary burner 16, air flow control valve 26, temperature sensor 28, each of which is positioned in primary combustion chamber 12, sensor 20 which is positioned in breach area 22 between primary combustion chamber 12 and secondary afterburner chamber 14, afterburner 38 and temperature sensor 30, each positioned within secondary afterburner chamber 14, and opacity sensor 36 which is positioned within stack 32. Afterburner 38 is on a separate and distinct circuit or loop in control system 66 from primary burner 16, air flow control valve 26, temperature sensor 28 in primary combustion chamber 12 and sensor 20. Further, there is no air intake into secondary afterburner chamber 14. The interconnections discussed relative to FIG. 4 have been omitted in FIGS. 1 and 2 for purposes of clarity.

While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.

Claims

1. A process for the cremation of animal remains, the process comprising the steps of:

a) inserting the animal remains into a primary combustion chamber of a cremation device;

b) igniting a primary burner in said primary combustion chamber of said cremation device;

c) measuring an oxygen content value of a gas leaving said primary combustion chamber, said oxygen content value being represented by an oxygen level information signal;

d) measuring a temperature of said primary combustion chamber, the temperature measured being represented by a primary temperature signal;

e) sensing volatilization of the animal remains dependent upon said oxygen level information signal and said primary temperature signal;

f) adjusting a volumetric flow rate of a gas fed into said primary burner;

g) adjusting a quantity of air being introduced into said primary combustion chamber dependent upon said oxygen level information signal and said primary temperature signal;

h) determining a degree of completion of cremation of the animal remains based upon said oxygen content value and expiration of a predetermined period of combustion time; and

i) extinguishing said primary burner when said oxygen content value exceeds a predetermined oxygen content value after said expiration of said predetermined period of combustion time.

2. The process according to claim 1, wherein said step of measuring said oxygen content of said gas leaving said primary combustion chamber uses a zirconia oxygen sensor to produce said oxygen level information signal.

3. The process according to claim 2, wherein said zirconia oxygen sensor is positioned in a breach area located between said primary combustion chamber and a secondary afterburner chamber, said secondary afterburner chamber being located below said primary combustion chamber.

4. (canceled)

5. The process according to claim 1, wherein said predetermined period of time is between approximately 10 and 15 minutes.

6. The process according to claim 5, further comprising the step of varying an air flow into said primary combustion chamber after said expiration of said predetermined period of time.

7. The process according to claim 6, wherein a controller executes steps of the process acting at least in part as a cascade control loop circuit, said circuit including a primary loop and a secondary loop, said primary loop being an air control loop, said secondary loop being a temperature control loop.

8. The process according to claim 7, wherein said step c) of measuring an oxygen content is repeatedly monitored and factored into a proportional-integral-derivative (PID) control algorithm.

9. The process according to claim 8, wherein said cascade control loop circuit causes an air flow control valve in said primary combustion chamber to vary a volumetric flow of air through said valve dependent upon said oxygen level information signal.

10. The process according to claim 9, wherein said air flow control valve controls a volumetric flow rate of said air flow to bring said air flow into stoichiometric balance with a quantity of a free fuel available in the animal remains.

11. The process according to claim 10, wherein said primary loop carries out said step of adjusting said quantity of an air introduced to said primary combustion chamber dependent upon a temperature in said primary combustion chamber.

12. The process according to claim 11, said primary loop maintaining an oxygen content in said primary combustion chamber in a range of between approximately 7 to 12%.

13. The process according to claim 12, wherein if said oxygen content measured by said zirconia oxygen sensor drops below 7%, then said controller will respond by raising a temperature within a predetermined temperature range in said primary combustion chamber.

14. The process according to claim 1, further comprising the step of detecting an end of the process after the expiration of a predetermined period of time and the occurrence of an elevation of said oxygen content above 12%, said predetermined period of time being dependent upon at least one of a weight of the animal remains, a container type, and an anticipated burn temperature range.

15. A process for the cremation of animal remains, the process comprising the steps of:

inserting the animal remains into a primary combustion chamber of a cremation device;

igniting a primary burner in said primary combustion chamber;

sensing volatilization of the animal remains using a sensor;

reducing a volumetric flow rate of a gas fed into said primary burner; and

adjusting a volumetric flow rate of air into said primary combustion chamber, said reducing and said adjusting steps being dependent upon volatilization sensed in said sensing step;

determining a degree of completion of cremation of the animal remains based upon an oxygen content value and expiration of a predetermined period of combustion time; and

extinguishing said primary burner when said oxygen content value exceeds a predetermined oxygen content value after expiration of said predetermined period of combustion time.

16. The process according to claim 15, wherein said sensor is a zirconia oxygen sensor positioned in a breach area between said primary combustion chamber and a secondary afterburner chamber.

17. The process according to claim 15, wherein said step of reducing a volumetric flow rate of a gas fed into said primary burner is sufficient to extinguish said primary burner.

18. The process according to claim 15, wherein said step of adjusting a volumetric flow rate of air into said primary combustion chamber further comprises using a cascade control loop circuit having a primary loop and a secondary loop, said primary loop being an oxygen control loop and said secondary loop being a temperature control loop.

19. The process according to claim 18, wherein said air flow control valve controls a volumetric flow rate of said air flow to bring said air flow into stoichiometric balance with a quantity of a free fuel available in the animal remains.