Batch pyrolysis system

Claim 2

A process for operating a pyrolysis type thermal decomposition system comprising the steps of: (a) providing a plurality of batch type furnaces, (b) heating waste type materials in a controlled manner in each furnace where said materials produce fumes exhausted through a fume outlet on each furnace as said waste materials are decomposed by thermal reaction; (c) providing one afterburner connected to the gas outlet of all of the furnaces for incinerating the fumes produced by said plurality of furnaces when said waste materials are heated in said furnace; and (d) operating said furnaces in a sequentially staged, overlapping manner to produce a generally constant supply of fumes to said afterburner.

Claim 3

The process of claim 1 wherein each of said furnaces is operated in a first step where the furnace temperature produces an endothermic reaction with said waste material until a residue remains, said first step producing fumes principally composed of volatiles with an oxygen content of no greater than about 2% and a second step where an exothermic reaction with said residue occurs to decompose said residue while producing a gaseous mixture of compounds and oxygen which is more than sufficient to support combustion of said compounds, and the fumes of both steps for each furnace being sent to said afterburner so that such afterburner is simultaneously incinerating (i) volatiles with insufficient oxygen to support combustion from one of said furnaces and (ii) compounds in a mixture having an oxygen concentration more than sufficient to support combustion from a second furnace.

Claim 4

The process of claim 1 wherein the temperature of said heating step is established at the instigation of said heating step at a value which produces a maximum rate of volatiles but which does not significantly exceed the volatile rate produced during the remainder of said cycle so that spiking of fumes do not occur and the heating process can be controlled.

Claim 5

The process of claim 1 further including the steps of (i) sensing the quantity of volatiles emitted by said waste material during said heating step and (ii) integrating the quantity of volatiles emitted by said waste material over an elapsed time period, and initiating said heating step for a second furnace only when rate of volatiles is decreased beyond a set limit and the integrated value at that time period is less than a predetermined value during said heating step for a first furnace.

Claim 6

The process of claim 1 further including the initial step of heating a sample of said waste material under controlled conditions to obtain a time-temperature relationship for said waste at an optimally constant energy rate in btu/hr of volume and varying the temperature of each of said furnaces over a time correlated to said time-temperature relationship to produce an optimally constant energy rate of volatiles for incineration by said afterburner.

Claim 7

The process of claim 1 further including the steps of providing said afterburner with a generally cylindrical combustion chamber having an annular base at one end; introducing the fumes from each furnace tangentially to the interior of said combustion chamber at discrete, circumferential locations so that all of said fumes circumferentially swirl about the interior of said chamber; introducing metered amounts of combustion air as a free standing jet adjacent said annular base end; introducing metered amounts of combustibles as make-up fuel to said combustion chamber; mixing said fumes from each furnace as said fumes swirl about said combustion chamber to produce a homogeneous fume mixture while mixing said combustion air with said swirling fume mixture as said free standing jet expands into said combustion chamber to produce a combustible fume mixture; combusting said combustible fume mixture in said combustion chamber at a stable point of ignition generally adjacent said annular base and continuing said combustion as said combustible fume mixture travels the length of said combustion chamber away from said annular base end.

Claim 8

The process of claim 6 further including the steps of sensing the temperature of said combustible fuel mixture in said chamber at a point remote from said annular base end and controlling said make-up fuel to increase said fuel when said sensed temperature drops below a fixed value.

Claim 9

The process of claim 7 further including the additional step prior to controlling said make-up fuel of initially increasing said combustion air when said temperature drops below a fixed value until said combustion air reaches a fixed value whereat said step of controlling said make-up fuel becomes effective.

Claim 10

A pyrolysis system comprising a plurality of batch type pyrolyzing furnaces for heating waste to decompose same by thermal reaction, each furnace having a fume outlet whereby gaseous mixtures produced in each furnace exit therefrom; a single afterburner in fluid communication with each fume outlet for incinerating the fumes produced by said plurality of furnaces irrespective of the gaseous mixture composition; and control means for operating said furnaces in a sequentially staged manner with overlapping cycles to produce a generally constant supply of fumes to said afterburner.

Claim 11

A pyrolysis system comprising a plurality of batch type pyrolyzing furnaces for heating waste to decompose same by thermal reaction, each furnace having a fume outlet whereby gaseous mixtures produced in each furnace exit therefrom; a single afterburner in fluid communication with each fume outlet for incinerating the fumes produced by said plurality of furnaces irrespective of the gaseous mixture composition; and control means for operating said furnaces in a sequentially staged manner with overlapping cycles to produce a generally constant supply of fumes to said afterburner.

Claim 12

The pyrolysis system of claim 9 wherein each of said furnaces include means to heat said waste under an atmosphere controlled in oxygen content; control means in said afterburner sensing the temperatures of said incinerated fumes, and controlling the operation thereof; and said control means is effective to (i) initially heat said waste in each furnace at predetermined temperatures correlated to the time at which said wastes are heated and (ii) overriding said predetermined temperature only by the temperature sensed by said control means in said afterburner.