GB2383400A

GB2383400A - Incineration apparatus

Info

Publication number: GB2383400A
Application number: GB0226718A
Authority: GB
Inventors: K D Buckley; E L Hough
Original assignee: FURNACE CONSTRUCTION CO Ltd
Current assignee: FURNACE CONSTRUCTION CO Ltd
Priority date: 2001-11-15
Filing date: 2002-11-15
Publication date: 2003-06-25
Also published as: GB0127420D0; GB0226718D0

Abstract

An incinerator includes means for producing a combustion zone 9 and having feed means 101 to feed a charge 100 into the combustion zone as it is combusted. The incinerator may include a charge loading space into which the charge is fed. The combustion zone may include means to generate and direct heat 1 at a predetermined region of the charge load space to produce or contribute to the combustion zone. The feed may include a conveyor belt 103 or pipe, and has a feed rate which may be adjustable, and is the same as the rate at which the charge is combusted. Heating means may be produced by a flame curtain or wall, and the combustion zone may operate at between 2000 and 4000 Celsius. The flame may be elongate, flat, or conical, and may be produced by burner nozzles 8. The nozzles may be arranged in a ring or horseshoe formation, fixed to a mounting plate 2, and surrounding the charge loading space. The incinerator may include means for cooling the charge 110, before delivery to the combustion zone. The charge may be a human or animal corpse, which may be in a coffin, or may be other combustible matter. The charge feeding direction may be horizontal, and the heat generating means may be perpendicular to the charge.

Description

INCINERATION APPARATUS The invention relates to the field of incineration apparatus, in particular for the incineration of human or animal material and including more specifically the field of cremators for the cremation of coffins.

In the field of cremation, a conventional cremator typically consists of an oven having a heated incineration chamber typically operated at 1000-1200 C and requiring pre-heating before it is ready for operation.

A coffin carrying a human corpse (together known as the charge) is loaded into the chamber and the access door to the chamber is closed. Once inside, combustion begins.

The chamber is typically provided with an inlet for an air supply to the combustion process and an outlet for exhaust gases. It typically takes 1.25 hours to 1.5 hours for the charge to be completely combusted by the hot environment of the oven chamber. In order to assist in the break-up of the charge, a supplementary gas burner may also be provided to direct a single flame onto the charge. This is located above the charge area.

The aim of the invention is to provide a more rapid incineration/cremation process than is presently available in the field of incinerators/cremators.

The incinerator of the invention may not only be aimed at the cremation of coffins but additionally or alternatively may also be intended for the incineration of a range of human, and/or animal and/or other combustible matter, e. g. including animal carcasses such as sheep or cattle or animal waste products, such as matter which is not intended for human consumption, and/or other such similar "wet" or semi-liquid matter in need of incineration.

According to a first aspect of the invention, an incinerator is envisaged including means for producing a combustion zone, and feed means to feed a charge into the combustion zone as the charge within the combustion zone is combusted.

This permits the front of the charge to be combusted or"vaporised as it enters the combustion zone i. e. a predetermined region of the loading space into which flames emanating from heat means such as burner nozzles are directed. In use, the feed means may be operated at the same time as part of the charge is being combusted.

Preferably the invention makes it possible to carry out the incineration process in an apparatus which is of smaller overall dimension than a conventional apparatus, as described above. Also the invention may carry out the incineration process in a so-called"cold"region, i. e. a

region which is not pre-heated in the sense of a conventional incinerator/cremation oven but instead only receives heat energy during operation. This not only to avoid lengthy pre-heating and cooling down periods, but also to save energy.

The incinerator preferably includes a charge loading space into which a charge is fed by feed means.

Preferably the means for producing the combustion zone includes one or more heat generation means and more preferably the or each heat generation means may be a burner, and the burner may be of the type which produces a flame. For example, the burner may be a gas burner or liquid fuel burner.

Preferably the heat generation means (e. g. the burner) is capable of directing heat, or a flame in the case of a burner, at a predetermined region of the charge loading space to produce or to contribute to the combustion zone.

In one embodiment, in use, the feed means e. g. a combustion line preferably transports a charge along at a rate which is substantially the same as the rate which the charge is combusted. Preferably feed rate adjustment means are provided which enable the feed rate to be adjusted for different types of charge. If the charge is delivered too rapidly, then combustion may not provide

the desirable substantially instantaneous "vaporisation" and solid matter will pass through the combustion zone.

If the charge is fed too slowly, then energy will be wasted and the heat delivered by the burners may arrive at other burners causing them to overheat and fail.

Preferably the incinerator is a cremator. In the case of a typical human coffin, the conventional duration of combustion of 1.25-1. 5 hours may be reduced to a time scale in the region of 5 minutes to incinerate a 2 metre length of coffin using an embodiment of the apparatus described above.

Preferably, the incineration process of the present invention achieves combustion by carbonisation and/or vaporisation of the surface of the charge in contact with the flame, the flame operating at a temperature between

2000 C and 4000 C and more preferably at a temperature in the region of or at 4000 C (e. g. 3500-4500 )- Carcasses may for example be delivered to the incinerator on a conveyor belt whereas semi-liquid matter may be delivered by being pumped along a pipe, or through a conveyor belt or such like to the charge loading space of the incinerator.

Preferably the heat generation means is/are usable to produce a flame curtain or wall which is at least part

of the combustion zone through which the charge passes in use.

More preferably, the heat generation means produce a clear or focussed combustion line in the charge loading space. This has been found to be a particularly energy efficient solution, giving rise to rapid vaporisation of the charge in the vaporisation zone. The following description refers to burners but may also apply to other types of heat generation means.

Where there is more than one burner, preferably the outputs (e. g. nozzles) of the burners are located in substantially the same plane (i. e. not staggered) in the charge loading direction within the incinerator.

This means that the burners are capable of concentrating their energy at one hot spot focal point into which, in use, the charge is fed.

The burner nozzles preferably project a flame of elongate or flattened cross-sectional shape so that the flame tends towards being flat or is substantially flat. Nevertheless, the flame may also or instead have a substantially conical propagation.

Preferably the centre lines of the flames of each of the nozzles are in substantially the same plane. In the case of a flattened flame e. g. of elongate crosssectional shape, then the plane of each of the flat

flames are preferably substantially in the same plane. These techniques may contribute to the production of a flame curtain or wall, into which the charge can be fed.

The centre lines of the projected flames are preferably substantially perpendicular to the charge feeding direction.

The direction of the heat propagation, (e. g. the burner nozzles), may nevertheless be directed at an inclination to a direction perpendicular to the charge feeding direction. The nozzles may be inclined at an angle such that they partially direct their respective flames in the charge feeding direction. Alternatively, the nozzles may be inclined such that they partially direct their respective flames in a direction opposite to the charge feeding direction, as desired. It is therefore not necessarily the case that the flame curtain needs to be perpendicular to the charge feeding direction and it may be inclined in other directions.

Preferably the heat generation means such as the nozzles (e. g. their output ends) define points substantially on a curve or arc which surround the charge loading space, which may be in a plane substantially perpendicular to the charge feeding direction. It has been found to be particularly advantageous for the curve to be in the form of a circle which then results in a

"ring" of e. g. burners and this is particularly easy to set up and adjust. The curve may alternatively be of a

substantially"horseshoe"shape, whereby no heat generator means (e. g. burner nozzles) are present at the "opening"of the horseshoe.

This horseshoe arrangement has been found to be advantageous in terms of ash deposition, collection and removal, when the gap in the curve is positioned at the underside of the charge loading space.

Alternatively, it has been found to be particularly advantageous in certain applications, where downward deposition of combusted material/ash is to be reduced or avoided, to place a heat generation means (e. g. a burner nozzle or nozzles) directly beneath the charge loading space. The end of the burner nozzle or nozzles beneath the charge loading space may but need not necessarily coincide with the arc of the rest of the nozzles.

Preferably all the burners are of substantially the same fuel delivery capability and therefore flame strength or power, and this results in a particularly even distribution of energy in the flame curtain and across the vaporisation zone. This makes the apparatus particularly easy to set up and use.

Preferably some or all of the heat generation means (e. g. burner nozzles) are equidistantly spaced along the curve.

If the burner nozzles located on opposite sides of the curve are too close to each other, then they will tend to heat each other up, to overheat, burn and fail.

Typically a curve, arc or circle diameter of less than about 200mm is less desirable because of such problems.

It has been found to be particularly advantageous in terms of avoiding unnecessary temperature rise in the burners for the burner nozzles to be arranged such that their respective flames are directed towards an area on the opposite side of the charge loading space where no burner nozzle is situated or towards the region between burner nozzles.

Preferably, the plurality of burner nozzles are arranged to direct their flames from above, and/or below and/or both sides of the charge loading space.

Preferably, the combustion produced extends in the direction of charge feed. For example, at least one of the heat generation means may be displaced with respect to another of the heat generation means in the direction of charge feed.

This has been found to be particularly useful where it is required to incinerate coffins and such like, which consist of essentially two elements, i. e. the coffin and the corpse.

According to a preferred embodiment, an additional or secondary array or ring of heat generation means (such as burners) is provided (which may be substantially identical to the first array), the secondary array being located behind (in the charge feeding direction) the primary set of burners described above, i. e. the charge being fed reaches the secondary array after the primary array.

The first array of burners are preferably arranged to combust (vaporise) the outer shell or coffin in order to in effect reduce the charge diameter, whereas the second set of burners is arranged to combust the corpse. The primary array or ring of burner nozzles typically are spaced from the centre of the combustion zone (e. g. on a diameter) of 700-1500mm, more preferably 800-1000mm (e. g. 900mm) for combusting a typical coffin, whereas the secondary array of burners are similarly spaced by 400-800, more preferably 500-700mm (e. g. 600mm) for combusting the corpse. Nevertheless, primary and secondary arrays of equal diameter are also envisaged.

This arrangement gives rise, in effect, to two combustion lines relating to each of two components of the charge.

Preferably distance adjustment means are provided for adjusting the distance of the heat generation means from the centre of the combustion zone (e. g. in a radial direction) in order to be adaptable to different charge requirements. This may be achieved by manual distance adjustment means, but may also be achieved by the use of mechanical drive means which are capable of retracting/extending the heat generation means (e. g. burners) in response to a command signal from a manual operator or from a charge sensor which detects information about the shape, size, nature of the charge. For example preferably the burner nozzles are arranged so as to be retractable Fuel may be delivered to the burners by flexible pipes to permit them to be retractable, but this need not be the case.

Preferably there are cooling means such that cooling of the charge, for example by means of water sprayers, takes place e. g. just before the charge is delivered to the flame curtain or combustion zone. This reduces the possibility that the combustion line spreads backwards, in an uncontrolled manner, out of the combustion zone and in a direction opposite to the direction of the charge feed.

The charge feeding direction is preferably substantially horizontal with the heat generation means (e. g. a plurality of burner nozzles) being positioned in a substantially vertical plane. The charge feed means preferably feeds the charge automatically to the combustion zone of the burners, for example by a mechanically driven conveyor. Adjustment means can also be provided to adjust the feed rate of the conveyor and this results in the advantage that the feed rate can be matched by a suitably designed controller to the combustion rate which the burners are capable of delivering for a particular charge or the combustion rate which is being delivered, as measured by suitable sensors. It is also envisaged that a sensor or system of sensors can be used to detect information indicative of the nature, size, shape, weight and such like of the charge and automatically adjust the feed rate accordingly.

Although the above preferred embodiments have described the heat generation means in terms of the features of a burner, it should be understood that these features are also intended to apply to any heat generation means which is used to produce the combustion zone. Therefore, references to flames, for example, may

apply equally to the heat propagation means of other heat generators.

According to a further aspect, the invention provides means for producing a combustion zone as described above.

According to a further aspect of the invention, a method of incinerating a charge is envisaged, the method including the steps of operating means to produce a combustion zone at a predetermined region, and feeding the charge into the combustion zone as the part of the charge within the combustion zone is combusted.

Preferably the method operates heat generation means (e. g. burners) to produce the combustion time. Preferably the burner produces a flame. The burner preferably receives fuel in the form of gas or liquid fuel.

Preferably heat is directed from the heat generation means or a flame (when heat generation means is a burner), at a predetermined region of the charge loading space to produce or to contribute to production of the combustion zone.

Preferably, a plurality of heat generation means are operated, i. e. burners, to produce the combustion zone. Preferably the pre-determined region of the charge loading space is the same for each of the plurality of burners. Preferably the heat generation means, i. e. the

burners, are directed at the same point within the charge loading space.

Other method features which may be used in combination with the method of the above further aspect will be apparent from the above description of the apparatus of the first aspect and its advantageous embodiments.

The invention will now be described by means of nonlimiting embodiments, with reference to the following drawings: Fig. l shows an end elevation of an array of burners. Fig. 2 shows a side elevation of a charge delivery arrangement, charge cooling arrangement and an array of burners.

Fig. l illustrates the burner array of an incinerator in the form of a cremator (1) for the cremation of coffins carrying human remains. The illustrated burner array includes a burner mounting plate (2) on which an array of individual burner assemblies (5,6, 8) are mounted. Each of the burner assemblies includes a pipe attachment means (5) which preferably includes individual pipe attachments for fuel supply pipes (3) and cooling water pipes (4).

The burner assemblies furthermore may also include a transfer pipe (6) for the delivery of fuel entering the

pipe attachment means (5) to a burner nozzle (8). In addition to one or more fuel passages in the transfer pipe (6), the transfer pipe may also includes one or more passages for cooling water, to enable cooling water to circulate to the burner nozzle (8). The two cooling water pipes (4) illustrated in Fig. l therefore represent the flow and return of cooling water to a specific burner. The rest of the cooling water piping is not illustrated, however it forms part of a larger cooling system for the delivery of cooling water to the burners and for the removal of heat from the cooling water.

In addition to cooling water, the pipe attachment means (5) may receive the ends of fuel supply pipes (3) which serve the purpose of circulating fuel between the burners as well as delivering fuel to individual burners.

Although the illustrated arrangement involves the use of three fuel supply pipes (3) attached to the pipe attachment means (5) of each of the burners, the invention would also work with a different arrangement of fuel supply pipes, for example involving a single fuel delivery pipe for each burner, or alternatively involving two fuel supply pipes in a flow and return arrangement so as to circulate fuel between the burners as well as to deliver part of the fuel to an individual burner.

The burner assemblies are preferably attached to the burner mounting plate (2) in a way which permits the burner assemblies (5,6, 8) to slide, substantially in the direction of the axis of the burner assembly, illustrated by the respective burner centrelines in Fig. 1. This is achieved, in the case of the illustrated embodiment, by the use of clamps (7) by which transfer pipes (6) are secured to the burner mounting plate (2). The clamps (7) are arranged to be releasable, e. g. they can be slackened off by a hand-held tool or such like, permitting the burner assembly to be extended or retracted along its axis relative to the charge loading space (9) of the incinerator. The clamp means (7) can then be tightened again in order to secure the burner in its new position relative to the mounting plate (2). In order to permit this axial movement of the burners, it is desirable for the fuel supply pipes (3) and cooling pipes (4) to have some inherent flexibility so as not to hinder the possibility of axially adjusting the burner assembly relative to the mounting plate.

The axial adjustment of the burner assembly permits the burner nozzle (8) to be set in a position which is either closer to or further away from the centre of the charge loading space (9), or when in use the combustion zone of the incinerator.

As illustrated in Fig. l, the incinerator (1) may be provided with eight individual burners (5,6, 8) spaced around an imaginary circle which in the illustrated embodiment coincides with a circular hole (10) in the mounting plate (2), the inside of which can loosely be regarded as the charge loading space (9) or when in use the combustion zone. As illustrated in Fig. 1 all of the burner nozzles, except the burner nozzle (8') are located just outside the imaginary circle. The burner nozzles, as well as the axis of their respective burner assemblies are directed towards the centre of the circle and therefore also of the charge loading space (9). This applies to all of the burner nozzles (8), including the burner nozzle (8') located beneath the charge loading space (9).

It will also be appreciated that the diameter D of the imaginary circle (10) can be adjusted by extending or retracting each of the burners axially. This can be done to optimise the heat intensity distribution across the vaporisation zone in coordination with other parameters of the incinerator such as charge delivery rate, fuel delivery rate to individual burners, burner nozzle directionality, nature of charge and so on.

The burner nozzles (8) are all directed to the same central region of the charge loading space (9) which can

therefore be regarded as a"hot spot focal point"of the flames emanating from the radial array of burners illustrated in Fig. l. The combined effect of the flames produced as a result of fuel being projected from the illustrated burner nozzles (8) is that a combustion zone in the form of a flame wall or curtain is produced across the charge loading space (9). The purpose of this is to combust or vaporise the front of the charge as it is delivered to the combustion zone. The flame curtain therefore progressively removes the front of the charge, creating in effect a combustion line which travels along the charge as it is being fed. On one side of the combustion line is the unburnt charge and on the other side is no solid matter to speak of, only gaseous combusted charge matter, residue and deposits of ash.

The underside burner (8') serves the purpose, in addition to contributing to the flame curtain, of tending to push any deposits of ash, residue and such like upwards and back towards the centre of the combustion zone (9). This is particularly useful in applications where it is desirable to produce little or no ash as a consequence of the incineration process. Examples of this include the incineration of animal carcases, waste meat products and such like.

Nevertheless, it should be understood that in applications where it is desirable to produce ash, for example in the cremation of human remains, then the underside burner (8') can be dispensed with so that the array of burner nozzles are aligned with the arc of part of an imaginary circle to produce what can figuratively be regarded as a horseshoe shaped configuration of burner nozzles. In the absence of a specific underside burner (8'), there is a greater tendency for solid deposits, i. e. ash to drop down under force of gravity towards the open end of the so-called horseshoe for collection on a tray (not illustrated).

In the illustrated embodiment, the imaginary circle on which the nozzles lie substantially coincides with a hole (10) through the burner mounting plate (2) around the combustion zone (9). However this need not necessarily be the case, and the end of burner nozzles (8) can project beyond or be set back from the edge of the hole (10) in the burner mounting plate (2). Similarly, the shape of the hole (10) has little or no effect on the functionality of the incinerator, and it need not therefore necessarily be of the circular form illustrated.

Fig. 2 illustrates an incinerator including the burner array (1) of Fig. 1, in end elevation, the

incinerator also including a charge machine (101) and a cooling stage (110). In the illustrated embodiment, a coffin (100) rests on a conveyor (103) which forms part of the top of the charge machine (101). The conveyor (103) is mechanically driven at a controlled rate (the feed rate) so as to deliver the charge (100) towards the vaporisation zone (9) of the incinerator in the direction illustrated by arrow (120). This arrow (120) therefore indicates the feed loading direction of the incinerator.

As can be seen from Fig. 2, the array of burners are arranged in a plane which is substantially perpendicular to the feed loading direction (120).

Also illustrated in Fig. 2 is a water cooling stage of the incinerator (110). The water cooling system includes an array of sprayer nozzles (111) which spray water onto the charge just before it passes into the vaporisation zone (9). Cooling water is delivered through a pipe system to the water cooling stage (110), the delivery pipe for the cooling water being shown as (102) in the figure. The purpose of these cooling sprays of water is to prevent any uncontrolled burning back of the charge away from the combustion zone which might occur as a result of the very intense heat associated with this incineration process.

Variations and modifications to the above embodiment will be apparent to a person skilled in the art.

Claims

CLAIMS 1. An incinerator including means for producing a combustion zone, and feed means to feed a charge into the combustion zone as the charge within the combustion zone is combusted.
2. An incinerator according to claim 1 including a charge loading space into which a charge is fed by the feed means, and the means for producing the combustion zone includes one or more heat generation means capable of directing heat, at a predetermined region of the charge loading space to produce or to contribute to the combustion zone.
3. An incinerator according to claim 1 or claim 2 wherein the feed means includes means for transporting a charge along at a rate which is substantially the same as the rate which the charge is combusted.
4. An incinerator according to claim 3 including feed rate adjustment means which enable the feed rate of the feed means to be adjusted for different types of charge.

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5. An incinerator according to claim 3 wherein the feed means includes a conveyor belt or a pipe.
6. An incinerator according to any one of claims 2-5 wherein the heat generation means is/are usable to produce a flame curtain or wall which is at least part of the combustion zone through which the charge passes in use.
7. An incinerator according to any of the above claims wherein the combustion zone in use operates at a temperature between 20000C and 4000 C.
8. An incinerator according to any one of claims 2-7 wherein the outputs of the heat generation means are located in substantially the same plane. The burner nozzles preferably project a flame of elongate or flattened cross-sectional shape so that the flame tends towards being flat or is substantially flat. Nevertheless, the flame may also or instead have a substantially conical propagation.
9. An incinerator according to claim 8 wherein the heat generation means are burners each having a nozzle which is usable to produce a flame and the centre lines of the

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flames of each of the nozzles are in substantially the same plane.
10. An incinerator according to claim 9 wherein in use the centre lines of the projected flames are substantially perpendicular to the charge feeding direction.
11. An incinerator according to any one of claims 2-9 in which the direction of the heat propagation of the heat generation means is at an inclination to a direction perpendicular to the charge feeding direction.
12. An incinerator according to claim 11 wherein the heat propagation is at an angle such that it is at least partially directed in the charge feeding direction or in a direction opposite to the charge feeding direction.
13. An incinerator according to any one of claims 2-12 wherein the outputs of the heat generation means define points substantially on a curve or arc which surrounds the charge loading space.

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14. An incinerator according to claim 13 wherein the curve or arc is in a plane substantially perpendicular to the charge feeding direction.
15. An incinerator according to claim 13 or claim 14 wherein the arc is a horseshoe and the gap in the horseshoe is positioned at the underside of the charge loading space.
16. An incinerator according to claim 13 or claim 15 wherein a heat generation means is located directly beneath the charge loading space.
17. An incinerator according to any one of claims 13-16 wherein some or all of the heat generation means are equidistantly spaced along the curve or arc.
18. An incinerator according to any one of claims 13-17 wherein the output of each heat generation means is arranged such that it is directed towards an area on the opposite side of the charge loading space where no other heat generation means is situated.
19. An incinerator according to any one of claims 13-18 including heat generation means spaced with respect to

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another of the heat generation means in the direction of charge feed.
20. An incinerator according to any one of claims 13-19 including a secondary array, curve, arc or ring of heat generation means, the secondary array being located behind (in the charge feeding direction) the heat generation means on the primary arc or curve.
21. An incinerator according to any one of claims 2-20 wherein distance adjustment means are provided for adjusting the distance of the heat generation means from the centre of the combustion zone.
22. An incinerator according to claim 21 wherein the distance is adjustable in a direction towards and/or away from the charge feeding direction.
23. An incinerator according to claim 21 or 22 wherein the distance adjustment means is capable of retracting and/or extending the heat generation means in response to information about the shape or size or nature of the charge.

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24. An incinerator according to any of the above claims including cooling means for cooling the charge, before the charge is delivered to the combustion zone.
25. An incinerator according to any one of claims 2-24 wherein the charge feeding direction is substantially horizontal and the heat generation means in a substantially vertical plane.
26. Means for producing a combustion zone according to any preceding claim.
27. A method of incinerating a charge including the steps of operating means to produce a combustion zone at a predetermined region, and feeding the charge into the combustion zone as the part of the charge within the combustion zone is combusted.
28. A method according to claim 27 wherein a plurality of heat generation means are operated, to produce the combustion zone.

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29. An incinerator substantially as any of the embodiments herein described with reference to the accompanying drawings.
30. A method substantially as any of the embodiments herein described with reference to the accompanying drawings.