Electric incinerator with electrostatic filter

Abstract

An electric incinerator for burning refuse indoors or in any other suitable location, including a built-in electrostatic filter which has an ionizer assembly, in the form of a plurality of negatively charged, vertically aligned pins, and a collector cell assembly, in the form of a like plurality of positively charged tubes mounted to overlie corresponding pins. Relatively small particles of debris carried in gases emitted from the burning refuse are ionized negatively as the gases rise through the ionizer assembly, and are attracted to surfaces of the collector cell assembly, which is removable from the incinerator for cleaning purposes. The incinerator also includes a combustion chamber in which the refuse is electrically heated to ignition point, and a conventional power supply connected through a manually adjustable timer to a heating element in the combustion chamber and having a high-voltage transformer supplying power to the electrostatic filter. Deflector plates mounted above the combustion chamber provide a lengthened path for the emitted hot gases and thereby cool them prior to filtering and expulsion. A deodorizing unit is optionally employed to freshen the expelled air.

Description

BACKGROUND OF THE INVENTION

This invention relates generally to electric incinerators for burning refuse, and, more particularly, it relates to electric incinerators including a filtering means for the reduction of objectionable emissions from refuse burned in the incinerator.

A salient disadvantage in previous incinerators is that gaseous by-products of the burning refuse contain relatively small particles of debris and objectionably odorous gases which must be expelled into the open air. Various filtering means have been employed to reduce the emissions, including electrostatic filtering in industrial filtering processes. However, filtering devices on previous incinerators have not been totally effective in filtering small particles and odorous gases emitted from incinerators adapted for use indoors such as in a home or office. Additionally, whatever filtering device is employed must be provided with some means for removing smoke and debris build-up. Otherwise, the filtering device will become blocked and will reduce the efficiency of the incinerator. Cleaning and/or replacement of the filtering devices in previously available incinerators is a costly if not impossible task. Furthermore, air expelled from these incinerators is quite typically at a temperature which is considerably too high to be expelled into a home or office, thus rendering the incinerators unusable indoors.

It will be apparent, then, that there is a real need for an electric incinerator in which solid products of combustion are for the most part removed by a conveniently serviceable filter, and which may be adapted for safe use in a home or office or any other suitable location.

SUMMARY OF THE INVENTION

The present invention resides in an electric incinerator comprising an electrostatic filter having at least a first and a second set of elements. The second set of elements places a negative charge on relatively small particles that are carried by hot gases from refuse burned in the incinerator. The first set of elements has a positive charge and attracts and collects the negatively-charged particles. Thus, the air within the incinerator is substantially filtered prior to expulsion from the incinerator.

A principal feature of the incinerator of the present invention is that one or both sets of elements can be easily and quickly removed from the incinerator for periodic cleaning to maintain the efficiency of the electrostatic filter.

Additionally, a combustion chamber in the incinerator has at least one deflector plate arranged so as to effectively create a longer passage through which the smoke and gases rise without increasing the outer dimensions of the incinerator. This maintains overall compactness as opposed to the bulky structure of previous incinerators. Furthermore, the longer passage allows for greater cooling of hot gases that are given off during combustion of the refuse, and consequently increases the effective life and efficiency of the electrostatic filter, and cools internal gases prior to their expulsion.

In addition to the forementioned elements, the incinerator comprises an insulated housing having a vent hole to allow for expulsion of the filtered gases, power supply means, timing means and means for thermally insulating said power supply and timing means from the burning refuse.

The incinerator also includes electric heating means for igniting the refuse and deodorizer means for substantially eliminating objectionably odorous fumes which would otherwise be emitted from said incinerator.

As will become more apparent from the following detailed description, taken in conjunction with the accompanying drawings, the present invention contains several salient advantages over previous incinerators in that it provides for the effective removal of objectionable emissions from burning refuse, and can be used indoors or in any other suitable location.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an electric incinerator embodying the invention;

FIG. 2 is an enlarged transverse cross-sectional view of the incinerator taken substantially along line 2--2 of FIG. 1;

FIG. 3 is a cross-sectional view of the incinerator taken substantially along line 3--3 of FIG. 2;

FIG. 4 is a further cross-sectional view of the incinerator taken substantially along line 4--4 of FIG. 2; and

FIG. 5 is a schematic diagram showing the electrical connections to the incinerator shown in FIGS. 1-4.

DETAILED DESCRIPTION

As shown in the drawings for purposes of illustration, the invention is embodied in an electric incinerator particularly well suited for home or office use, wherein small quantities of refuse can be quickly and conveniently disposed of without expelling smoke and hot, objectionably odorous gases from the incinerator.

In general, the incinerator comprises an outer thermally insulated housing 6, shown most clearly in FIG. 1, having a combustion chamber 7, (FIG. 2) for receiving and burning refuse and located generally in the lowermost section of the housing 6, a burning plate 8 located in the lowermost section of the combustion chamber 7 for igniting the refuse, and a vent hole 9 in the top which allows internal air to escape to the outside atmosphere.

In accordance with a primary aspect of the present invention, the electric incinerator has an electrostatic filter for effective removal of relatively small particles of debris in the smoke and gases prior to their expulsion through the vent hole 9. The electrostatic filter comprises an ionizer assembly 10 and also a collector cell assembly 11 both of which can be easily and quickly removed for periodic cleaning to maintain the efficiency of the electrostatic filter. Both the ionizer assembly 10 and the collector cell assembly 11 are located in the upper rear portion of the housing 6. Furthermore, the combustion chamber 7 in the incinerator has a first deflector plate 12 and a second deflector plate 14 arranged so as to effectively create a longer passage through which the smoke and gases rise without increasing the outer dimensions of the incinerator. This deflected path, or labyrinth passage, allows for overall compactness of the incinerator and eliminates the bulky housing common to incinerators available heretofore. Additionally, the labyrinth passage tends to cool the rising smoke and gases from the burning refuse and consequently increases the effective life and efficiency of the electrostatic filter and reduces the temperature of air expelled from the incinerator.

The deflector plates 12 and 14, as best illustrated in FIGS. 2 and 4, are rectangularly shaped with an opening at one end to allow for the passage of the rising smoke and gases. The deflector plates 12 and 14 are mounted in the combustion chamber 7, above the burning plate 8, in separate, parallel horizontal planes, and are oriented so that an opening 16 in the first deflector plate 12 is near a front wall 18 of the housing 6 and an opening 20 in the second deflector plate 14 is near a rear wall 22 of the housing. It will be appreciated that although the deflector plates 12 and 14 are shown in the illustrative embodiment as having their openings 16 and 20 at the front and rear, respectively, the plates could equally well be oriented with the openings located in the opposite positions, or even located near opposing side walls of the combustion chamber. The smoke and gases from the burning refuse rise substantially along line 24 (FIG. 2) through the opening 16 in the first deflector plate 12 then rearwardly and upwardly through the opening 20 in the second deflector plate 14. The smoke and gases continue to rise through the electrostatic filter, where a filtering process to be described later takes place, past a deodorizer pan 26 and finally through the vent hole 9 into the outside air.

The ionizer assembly 10 of the electrostatic filter comprises a plurality of electrically conductive polarizing pins 28 (for example, fifteen are used in a presently preferred embodiment), made preferably of metal, and a perforated non-conductive board 30 of asbestos phenolic material or any suitable equivalent. The board 30 is relatively thin and rectangular shaped and is releasably mounted in the housing 6 in a horizontal plane above the combustion chamber 7 and toward the rear wall 22 of the housing 6. The board 30 is perforated to allow for the passage of the smoke and gases given off during combustion of the refuse. The polarizing pins 28 are pointed at one end and rigidly mounted on the board 30, perpendicular to the board. The polarizing pins 28 are arranged parallel to each other in a grid-like pattern and extend through and for the most part above the board 30. The pointed ends point up and relatively flush with the bottom of said board.

The collector cell assembly 11 comprises a rectangular shaped relatively thin metallic plate 32, made of a lightweight conductive material such as aluminum, and a plurality of relatively thin-walled tubes 34, corresponding in number to the polarizing pins 28, made also of a lightweight conductive material such as aluminum. The collector cell assembly 11 is releasably secured to the housing by a rear access cover plate 35 and lies in a horizontal plane above and parallel to the ionizer assembly 10. The thin-walled tubes 34 are rigidly mounted to the bottom of the plate 32, perpendicular to the plate, and extend vertically downward therefrom. The thin-walled tubes 34 are arranged parallel to each other in the same grid-like pattern of the polarizing pins 28, and are positioned so that each tube 34 is centered over and relatively close to the corresponding polarizing pin 28. The removable rear access cover 35 is releasable mounted to the rear of the housing 6 with wing nuts (not illustrated) and is provided to allow for the removal of the collector cell assembly 11 and the ionized assembly 10 for periodic cleaning.

The incinerator includes a power supply means for the electrostatic filter made up of a conventional high-voltage transformer 36 having a secondary voltage of 14,000 volts in the presently preferred embodiment of the invention, a conventional rectifier and voltage doubler circuit 38, and a timer 40 which controls the length of time current is applied to an electrical heating element 42 of the burning plate 8 and the transformer 36. The incinerator has an inner thermally insulated chamber 44, located in the upper frontmost section of the housing 6, wherein the transformer 36, timer 40 and rectifier and voltage doubler circuit 38 are mounted and thermally insulated from the combustion chamber 7.

The incinerator requires only conventional house current for operation. The current is applied through terminals 46 and 48 on the rear wall 22 and through the timer 40 to the burning plate 8 over line 50 and to the transformer 36 over line 52. The transformer 36 is electrically connected by lines 54 and 56 (FIG. 5) to the rectifier and voltage doubler circuit 38 to convert the incoming current from AC to DC and to effectively increase the voltage. The resultant positive DC voltage is applied over line 58 to the conductive tubes 34 of the collector cell assembly 11 and the negative voltage is applied over line 60 to each of the conductive polarizing pins 28 of the ionizer assembly 10. Rising particles in the smoke and gases from the burning refuse become negatively polarized by the ionizing effect of a corona surrounding the pointed ends of the polarizing pins 28 as the particles pass through the ionizer assembly 10. The positively charged conductive tubes 34 then attract the negatively charged particles and collect the particles on the surface of the conductive tubes, thus filtering the air of substantially all relatively small particles of debris. The remaining air continues to rise through the collector cell assembly 11, past the deodorizer pan 26 and out of the incinerator through the vent hole 9. A few drops of an air freshening solution or any other suitable substitute may be placed into the deodorizer pan 26 to freshen the expelled air.

The burning plate 8 comprises, in addition to the heating element 42, connectors 62 and 64 (FIG. 3), a rectangular base plate 66 and front and rear upstanding walls 68 and 70. A handle 72 is mounted on the front upstanding wall 68 and is provided for slidably opening the burning plate 8, wherein the refuse may be deposited. The burning plate 8 slides out through the front wall 18 of the housing 6.

The heating element 42, as shown most clearly in FIGS. 2 and 3, is of conventional design and has sufficient wattage capacity to generate ignition temperatures for the refuse. The heating element 42 is elongated, bent to be supported substantially in a horizontal plane above the base plate 66, and secured by its ends to the rear upstanding wall 70. The heating element 42 is electrically connected to connectors 62 and 64 which are mounted on the wall 70 of the burning plate 8 and connected to connectors 74 and 76, respectively. As is shown in FIG. 5, outside current is applied to one end of the heating element 42 through the connector 62, over line 78, and to the other end through the timer 40, over lines 80 and 50, and through the connector 64. As a safety feature, sliding the burning plate to an open position disconnects the connectors 62 and 64 from the connectors 74 and 76 and prevents current flow to the heating element 42.

In operation, the burning plate 8 is slid open and the refuse is placed therein. The burning plate 8 is returned to its closed position and the timer 40 is set to an appropriate length of time for burning the refuse. When the timer 40 is set, current is applied to the heating element 42 and the electrostatic filter. The refuse is ignited and the resultant smoke and gases rise (substantially along the path illustrated by line 24 in FIG. 2), through the opening 16 at the front of the first deflector plate 12 then rearwardly and upwardly through the opening 20 at the rear of the second deflector plate 14. The smoke and hot gases continue to rise through the electrostatic filter, where the filtering process previously described takes place, past the deodorizer pan 26 and finally through the vent hole 9 into the outside air.

From the foregoing, it will be apparent that the present invention provides a new and improved electric incinerator having a number of significant features which cooperate to make the incinerator effective in disposing of refuse without expelling smoke and objectionably odorous gases. It also will be apparent that, while a preferred embodiment of the incinerator has been illustrated and described, various modifications may be made without departing from the spirit and scope of the invention.

Claims

I claim:

1. An electric incinerator comprising:

a thermally insulated housing having a vent to allow for expulsion of air from said incinerator;

a combustion chamber within said housing, for receiving refuse material to be burned within said incinerator;

heating means within said combustion chamber for igniting the refuse;

electrostatic filter means having at least a first set of elements and a second set of elements for filtering relatively small particles of debris in gaseous products from refuse burned in said incinerator;

power supply means for applying current to said heating means and applying relatively high voltage to said electrostatic filter; and

means for removably securing at least one of said first and second sets of elements of said electrostatic filter means in said housing, whereby said first and second sets of elements may be easily and quickly removed from said housing for periodic cleaning of debris build-up.

2. An electric incinerator comprising:

a thermally insulated housing having a vent to allow for expulsion of air from said incinerator;

a combustion chamber within said housing, for receiving refuse material to be burned within said incinerator;

heating means within said combustion chamber for igniting the refuse, said heating means being slidably removable from said housing from a closed to an open position for depositing refuse therein for burning;

electrostatic filter means having at least a first set of elements and a second set of elements for filtering relatively small particles of debris in gaseous products from refuse burned in said incinerator; and

power supply means for applying current to said heating means and applying relatively high voltage to said electrostatic filter.

3. An electric incinerator as defined in claim 2, wherein said heating means, in its closed position, is electrically connected to said power supply means, and electrically disconnected from said power supply means in its open position.

4. An electric incinerator comprising:

a thermally insulated housing having a vent to allow for expulsion of air from said incinerator;

a combustion chamber within said housing, for receiving refuse material to be burned within said incinerator;

heating means within said combustion chamber for igniting the refuse;

electrostatic filter means having at least a first set of elements and a second set of elements for filtering relatively small particles of debris in gaseous products from refuse burned in said incinerator; and

power supply means for applying current to said heating means and applying relatively high voltage to said electrostatic filter, said power supply means including a relatively high voltage transformer and a rectifier and voltage doubler circuit for applying a positive and a negative voltage to said first and second sets of elements of said electrostatic filter means, respectively.

5. An electric incinerator comprising:

a thermally insulated housing having a vent to allow for expulsion of air from said incinerator;

electrostatic filter means having at least a first set of elements and a second set of elements for filtering relatively small particles of debris in gaseous products from refuse burned in said incinerator, said first set of elements including a plurality of electrically conductive, positively charged tubes and said second set of elements including a plurality of electrically conductive, negatively charged pins, said tubes and said pins being arranged in separate gridlike patterns, whereby each tube is suspended over and coaxially aligned to its respective pin, and said pins place a negative charge on the particles of debris, and said tubes, being positively charged, attract and collect the negatively charged particles, thereby substantially filtering the gaseous products of combustion;

a combustion chamber within said housing, for receiving refuse material to be burned within said incinerator;

heating means within said combustion chamber for igniting the refuse;

power supply means for applying current to said heating means and applying a relatively high voltage to said electrostatic filter means, thereby applying a positive voltage to said first set of elements and a negative voltage to said second set of elements, said power supply means including a relatively high voltage transformer and a rectifier and voltage doubler circuit for applying a positive and a negative voltage to said tubes and said pins of said electrostatic filter means, respectively; and

at least one deflector plate mounted in said combustion chamber and defining in part a path for the gaseous products of combustion between said combustion chamber and said vent, whereby the path is effectively lengthened without increasing the outer dimensions of said incinerator to allow for cooling of the gaseous products.

6. An electric incinerator as defined in claim 5, wherein said first set of elements of said electrostatic filter means includes, in addition to said plurality of tubes, an electrically conductive plate, said tubes being mounted to said plate.

7. An electric incinerator as defined in claim 6, wherein said second set of elements of said electrostatic filter means includes, in addition to said pins, a non-conductive perforated board, said pins being electrically connected to each other and mounted to said board.

8. An electric incinerator as defined in claim 7, further including means for removably securing at least one of said first and second sets of elements of said electrostatic filter means to said housing, whereby said first and second sets of elements may be easily and quickly removed from said housing for periodic cleaning of debris build-up.

9. An electric incinerator as defined in claim 8, including adjustable timing means connected to said power supply means to apply power to said heating means and said electrostatic filter means for a preselected time.

10. An electric incinerator as defined in claim 9, wherein said heating means is slidably removable from said housing from a closed to an open position for depositing refuse therein for burning.

11. An electric incinerator as defined in claim 10, wherein said heating means, in its closed position, is electrically connected to said power supply means, and electrically disconnected from said power supply means in its open position.

12. An electric incinerator as defined in claim 11, further including deodorizer means mounted adjacent said vent to freshen air expelled from said housing.