Combustion kiln system and method of operating the same

Abstract

A combustion kiln system, comprising: a pre-heating chamber which is supplied with waste product; and a combustion chamber which receives the waste product from the pre-heating chamber and in which the waste product is incinerated; wherein the pre-heating chamber heats the waste product to remove moisture from the waste product prior to transfer to the combustion chamber.

1 . A combustion kiln system, comprising:
 a combustion chamber in which waste product is incinerated;   wherein the combustion chamber comprises a cavity, and a transfer mechanism which provides a grate at a floor of the combustion chamber and transfers the waste product through a combustion zone, the transfer mechanism comprising at least one stepped assembly over which the waste product is transferred, and the at least one stepped assembly comprising a plurality of steps which are arranged in downwardly-descending relation and a plurality of movable members which are movable reciprocally in relation to the steps to transfer the waste product along and over the steps.   
     
     
         2 . The system of  claim 1 , further comprising:
 a pre-heating chamber which is supplied with the waste product, wherein the pre-heating chamber heats the waste product to remove moisture from the waste product and the combustion chamber receives the pre-heated waste product from the pre-heating chamber, optionally the pre-heating chamber comprises a cavity through which the waste product is displaced, optionally the pre-heating chamber includes a plurality of air inlets which feed heated air into the cavity of the pre-heating chamber, optionally the pre-heating chamber includes a plurality of vents through which a gas stream is vented, optionally the temperature within at least an upstream region of the cavity of the pre-heating chamber is maintained at a temperature of less than 600 C, such that moisture is removed from the waste product without any substantial release of chlorides from the waste product.   
     
     
         3 . The system of  claim 1 , wherein the steps are arranged substantially in spaced, parallel relation, and the movable members are configured such that upper and lower surfaces of the members are in close relation to adjacent surfaces of the steps, whereby an action of withdrawing the movable members acts to scrape the waste product therefrom. 
     
     
         4 . The system of  claim 1 , wherein:
 (i) the steps are formed from a plurality of elements which are arranged in adjacent lateral relation, optionally the elements of the steps each comprise a main body part, and a cover part which is located over the main body part;   (ii) the steps include apertures through which an air flow can be driven upwardly into the cavity of the combustion chamber;   (iii) the movable members are formed from a plurality of elements which are arranged in adjacent lateral relation, optionally the elements of the movable members each comprise a main body part, and a cover part which is located over the main body part;   (iv) the movable members include apertures through which an air flow can be driven upwardly into the cavity of the combustion chamber; and/or   (v) ones or groups of ones of the movable members are movable independently of one another, so as to enable control of an amount of the waste product in the combustion zone, optionally the movable members are configured in a plurality of groups.   
     
     
         5 . The system of  claim 1 , wherein the combustion chamber further comprises an air supply unit which supplies air to the cavity of the combustion chamber, optionally the air supply unit comprises a plurality of air supplies which supply air to the combustion chamber, optionally the air supplies supply air to the combustion chamber from beneath the transfer mechanism, optionally the air supplies each comprise a channel which has an upper end which opens to a respective region of the transfer mechanism and a supply port from which air is delivered, optionally the channel has an open lower end which opens to a channel which allows for collection of ash which falls through the transfer mechanism, optionally the supply ports are controllable, optionally valved, to regulate a rate of flow of air from the respective air supplies, optionally the transfer mechanism and the air supply unit are integrally formed as a removable assembly, optionally the removable assembly is slideably disposed on slides. 
     
     
         6 . The system of  claim 1 , further comprising:
 a heat exchanger unit which is heated at least by heated gas from the combustion chamber to provide a heated fluid medium, optionally the heat exchanger unit comprises a first heat exchanger which is fluidly connected to the combustion chamber and utilizes heat of a gas stream from the combustion chamber, optionally the heat exchanger unit further comprises a second heat exchanger which is fluidly connected to the pre-heating chamber and utilizes heat of a gas stream from the pre-heating chamber, optionally an outlet of the second heat exchanger is fluidly connected to an inlet of the first heat exchanger, whereby the second heat exchanger pre-heats a fluid medium, and the first heat exchanger receives the pre-heated fluid medium from the second heat exchanger and further heats the pre-heated fluid medium to provide a superheated fluid medium.   
     
     
         7 . A combustion kiln system, comprising:
 a pre-heating chamber which is supplied with waste product; and   a combustion chamber which receives the waste product from the pre-heating chamber and in which the waste product is incinerated;   wherein the pre-heating chamber heats the waste product to remove moisture from the waste product prior to transfer to the combustion chamber.   
     
     
         8 . The system of  claim 7 , wherein the pre-heating chamber comprises a cavity through which the waste product is displaced, optionally the pre-heating chamber includes a plurality of air inlets which feed heated air into the cavity of the pre-heating chamber, optionally the pre-heating chamber includes a plurality of vents through which a gas stream is vented, optionally the temperature within at least an upstream region of the cavity of the pre-heating chamber is maintained at a temperature of less than 600 C, such that moisture is removed from the waste product without any substantial release of chlorides from the waste product. 
     
     
         9 . The system of  claim 7 , wherein the combustion chamber comprises a cavity, and a transfer mechanism which provides a grate at a floor of the combustion chamber and transfers the waste product from the pre-heating chamber through a combustion zone, optionally the combustion chamber further comprises an air supply unit which supplies air to the cavity of the combustion chamber, optionally the air supply unit comprises a plurality of air supplies which supply air to the combustion chamber, optionally the air supplies supply air to the combustion chamber from beneath the transfer mechanism, optionally the air supplies each comprise a channel which has an upper end which opens to a respective region of the transfer mechanism and a supply port from which air is delivered, optionally the channel has an open lower end which opens to a channel which allows for collection of ash which falls through the transfer mechanism, optionally the supply ports are controllable, optionally valved, to regulate a rate of flow of air from the respective air supplies, optionally the transfer mechanism and the air supply unit are integrally formed as a removable assembly, optionally the removable assembly is slideably disposed on slides. 
     
     
         10 . The system of  claim 7 , further comprising:
 a heat exchanger unit which is heated at least by heated gas from the combustion chamber to provide a heated fluid medium, optionally the heat exchanger unit comprises a first heat exchanger which is fluidly connected to the combustion chamber and utilizes heat of a gas stream from the combustion chamber, optionally the heat exchanger unit further comprises a second heat exchanger which is fluidly connected to the pre-heating chamber and utilizes heat of a gas stream from the pre-heating chamber, optionally an outlet of the second heat exchanger is fluidly connected to an inlet of the first heat exchanger, whereby the second heat exchanger pre-heats a fluid medium, and the first heat exchanger receives the pre-heated fluid medium from the second heat exchanger and further heats the pre-heated fluid medium to provide a superheated fluid medium.   
     
     
         11 . A method of incinerating waste product, optionally municipal solid waste (MSW) or refuse-derived waste (RDF), comprising:
 pre-heating waste product in a pre-heating chamber;   transferring the pre-heated waste product to a combustion chamber; and   incinerating the waste product in the combustion chamber;   wherein the pre-heating chamber heats the waste product substantially to remove moisture from the waste product prior to transfer to the combustion chamber.   
     
     
         12 . The method of  claim 11 , wherein the pre-heating chamber comprises a cavity through which the waste product is displaced, optionally the pre-heating chamber includes a plurality of air inlets, and further comprising:
 feeding heated air into the cavity of the pre-heating chamber through the air inlets, optionally the pre-heating chamber includes a plurality of vents through which a gas stream is vented.   
     
     
         13 . The method of  claim 12 , wherein the temperature within at least an upstream region of the cavity of the pre-heating chamber is maintained at a temperature of less than 600 C, such that moisture is removed from the waste product without any substantial release of chlorides from the waste product. 
     
     
         14 . The method of  claim 11 , wherein the combustion chamber comprises a cavity, and the waste product is transferred by a transfer mechanism which provides a grate at a floor of the combustion chamber, optionally the transfer mechanism comprises at least one stepped assembly over which the waste product is transferred, optionally the at least one stepped assembly comprises a plurality of steps which are arranged in downwardly-descending relation, and a plurality of movable members which are movable reciprocally in relation to the steps to transfer the waste product along and over the steps, optionally the steps are arranged substantially in spaced, parallel relation, and the movable members are configured such that upper and lower surfaces of the members are in close relation to adjacent surfaces of the steps, whereby an action of withdrawing the movable members acts to scrape the waste product therefrom. 
     
     
         15 . The method of  claim 11 , wherein:
 (i) the steps are formed from a plurality of elements which are arranged in adjacent lateral relation, optionally the elements of the steps each comprise a main body part, and a cover part which is located over the main body part;   (ii) the steps include apertures through which an air flow can be driven upwardly into the cavity of the combustion chamber;   (iii) the movable members are formed from a plurality of elements which are arranged in adjacent lateral relation, optionally the elements of the movable members each comprise a main body part, and a cover part which is located over the main body part; and/or   (iv) the members include apertures through which an air flow can be driven upwardly into the cavity of the combustion chamber.   
     
     
         16 . The method of  claim 11 , further comprising:
 moving ones or groups of ones of the movable members independently of one another, so as to control an amount of the waste product in the combustion zone, optionally the movable members are configured in a plurality of groups.   
     
     
         17 . The method of  claim 11 , further comprising:
 supplying air to the combustion chamber from an air supply unit, optionally the air supply unit comprises a plurality of air supplies which supply air to the combustion chamber, optionally the air supplies supply air to the combustion chamber from beneath the transfer mechanism, optionally the air supplies each comprise a channel which has an upper end which opens to a respective region of the transfer mechanism and a supply port from which air is delivered, optionally the channel has an open lower end which opens to a channel which allows for collection of ash which falls through the transfer mechanism, optionally further comprising:   controlling the supply ports, optionally valving, to regulate a rate of flow of air from the respective air supplies.   
     
     
         18 . The method of  claim 11 , further comprising:
 heating a heat exchanger unit with at least heated gas from the combustion chamber to provide a heated fluid medium, optionally the heat exchanger unit comprises a first heat exchanger which is fluidly connected to the combustion chamber and utilizes heat of a gas stream from the combustion chamber, optionally the heat exchanger unit further comprises a second heat exchanger which is fluidly connected to the pre-heating chamber and utilizes heat of a gas stream from the pre-heating chamber, optionally an outlet of the second heat exchanger is fluidly connected to an inlet of the first heat exchanger, whereby the second heat exchanger pre-heats a fluid medium, and the first heat exchanger receives the pre-heated fluid medium from the second heat exchanger and further heats the pre-heated fluid medium to provide a superheated fluid medium.   
     
     
         19 . The method of  claim 11 , further comprising:
 supplying the waste product from a waste product supply to the pre-heating chamber.   
     
     
         20 . The method of  claim 11 , wherein the waste product supply comprises at least one hopper which contains the waste product, and further comprising:
 feeding the waste product from the at least one hopper to the pre-heating chamber using a feed mechanism, optionally the feed mechanism comprises at least one ram which is actuated reciprocally between a first, material-receiving position, in which the waste product can fall from the at least one hopper in front of the at least one ram, and a second, feed position, in which the waste product ahead of the at least one ram is fed into the pre-heating chamber.