The present invention relates generally to incinerators, and more particularly to incinerators for disposing of animal carcasses.
Incinerators are well known in the art, and are used to dispose of a variety of materials. For example, incinerators are used for disposing hazardous waste, waste gases, garbage and other refuse, such as sewage sludge, scrap tires, etc. Incinerators range in size from small batch-fired incinerators to large mechanically fired industrial incinerators. In some large incinerators, the waste product is moved through the furnace on traveling grates so that combustion conditions are made nearly uniform over the waste product. Other large incinerators employ inclined reciprocating grates, drum grates, rocking grates and rotating kilns to provide agitation of the burning refuse.
Incinerators for animal carcasses are generally of the small batch-fired type. They are particularly useful to farmers for disposing of dead poultry and livestock. In animal carcass incinerators, factors such as cost and fuel efficiency are very important. Unlike the very expensive large industrial-type incinerators, animal carcass incinerators sell generally between one and two thousand dollars. Accordingly, cost factors are very important in the design of animal carcass incinerators.
Animal incinerators generally comprise an incineration chamber, a burner which produces a flame directly into the chamber, and an exhaust or smoke stack extending upwardly from the top of the incineration chamber. The shell of the chamber generally comprises a steel material. The steel shell is conventionally lined with a high temperature insulating material, such as refractory cement or firebrick.
U.S. Pat. No. 3,176,634 proposes a typical incinerator for farm use. This incinerator comprises a shell lined with firebrick and includes a stainless steel grate for supporting the waste product. A burner is positioned to produce a flame in the chamber beneath the grate. An afterburner is disposed near the top of the incinerator for reducing or eliminating combustible products in the exhaust gases.
Other types of lined incinerators have been proposed. For example, U.S. Pat. No. 3,177,827 proposes an incinerator having an outer steel casing and a stainless steel liner spaced from the casing and extending around the sides of the casing. A W-shaped grate is secured within the chamber, and a burner is provided to produce a flame beneath the grate.
U.S. Pat. No. 3,508,505 proposes an animal carcass incinerator in which the burner is positioned at the same end of the chamber as the exhaust stack. The draft of the flame from the burner forces the combustion products to travel around the far end of the grate, back beneath the grate, and then up and around the opposite end of the grate and out the exhaust stack.
Although grates aid in the combustion process, it has been found that grates quickly deteriorate in repeated use and require frequent replacement. In the cost-conscious environment of animal incinerators, this is a particularly troublesome problem. More recently, incinerators have been developed that do not include grates. For example, U.S. Pat. No. 4,000,705 proposes an incineration process in which the carcasses are placed directly on the bottom of the incineration chamber, and the burner emits a flame that substantially engulfs the chamber to decompose the animal tissue under starved air conditions. Unlike prior incinerators, the burner of this incinerator does not rely on the draft created by the exhaust stack but rather produces the appropriate fuel-air ratio by means of an air damper within the burner itself. As a result, the incineration process is performed under starved air conditions which has been found to produce superior results over prior incineration processes.
Although the incinerator of U.S. Pat. No. 4,000,705 has performed effectively, efforts are continuously directed toward improving upon this incineration process.
The present invention, in one form thereof, provides a grateless incinerator for disposing of animal carcasses, wherein the shell is lined with a fibrous insulation material and a steel liner, wherein the steel liner can be heated to temperatures sufficient to incinerate the portion of the animal carcass that is in engaging contact with the steel liner. In one embodiment, at least the lower half of the incineration chamber is lined with stainless steel to assure that the carcass is in direct contact with the stainless steel liner.
In addition, the present invention provides, in one form thereof, a process of incineration wherein the temperature of the incineration chamber is controlled as a function of the temperature of the chamber, and not as a function of time. The flame is directed onto a carcass supported on a stainless steel liner within the incineration chamber, wherein the heat generated by the stainless steel liner both above and below the carcass decomposes the carcass into substantially clean ash. The present invention provides, in yet another embodiment, an incinerator, wherein the interior of the incinerator includes a wall therein that separates the interior into a primary incineration chamber and an afterburner chamber disposed alongside the primary chamber and sharing a common wall therewith.
The invention provides in one form thereof, an incinerator having a cylindrical housing or shell with a burner at one end thereof and an exhaust stack at an opposite end thereof. The interior surface of the housing is circumferentially lined with a fibrous ceramic insulation material, and the fibrous insulation is lined with a stainless steel material bolted onto the housing. The fibrous insulation permits the stainless steel liner to heat up to a temperature that cannot be achieved in non-insulated incinerators. The bottom of the carcass in contacting engagement with the liner is thus heated sufficiently to caused a conductive heating similar to the type of heating experienced by a food product being cooked in a frying pan.
In another embodiment of the present invention, an incinerator comprises a shell or housing, wherein the interior of the shell includes an upstanding wall which divides the shell into two combustion chambers alongside one another and sharing a common wall. The wall may be made of stainless steel and includes an opening therein for air communication between the two chambers. A burner is disposed at an end of the primary combustion chamber. The secondary or afterburner chamber includes a second burner disposed adjacent the opening in the wall and is designed to heat the air as it enters from the primary combustion chamber. In one embodiment, the inner surface of the entire shell is lined with a fibrous insulation material, which is then lined with steel.
An advantage of the incinerator of the present invention is that it incinerates a charge to substantially ash with less energy input than that required by conventional incinerators.
Another advantage of the incinerator of the present invention is that it completely incinerates a charge without a grate and without requiring periodic agitation of the charge.
Another advantage of the incinerator of the present invention is that it incinerates with lower emissions than conventional incinerators.
Yet another advantage of the incinerator of the present invention is that the stainless steel liner will not warp or degrade upon repeated uses, thereby providing a substantially maintenance-free incinerator.
Another advantage of the incinerator of the present invention is that it provides an improved heating cycle to enable the user to have more control over the combustion process.
Other advantages will become apparent in the detailed description as follows.