Ashing furnace

A furnace for burning a combustible material comprising:

• a combustion chamber having a top wall, a bottom wall, a rear wall, two side walls and an access door;
• a support mounted within the combustion chamber for supporting the combustible material;
• a first heater element comprising a first heater plate mounted at the top wall of the combustion chamber for burning the combustible material;
• an exhaust path interconnecting the combustion chamber and an exhaust port communicating with the environment;
• a filter disposed in the exhaust path and having an input and an output with the input in communication with the combustion chamber, the filter filtering uncombusted products of combustion of the burning combustible material exhausting the combustion chamber via the exhaust path;
• a second heater element disposed in the exhaust path adjacent the output of the filter for burning uncombusted products of combustion passing through the output of the filter;
• a bypass path having an inlet in fluid communication with the combustion chamber and an outlet disposed between the filter and the second heater element, the bypass path shunting the products of combustion from within the combustion chamber around the filter to the second heater and providing an alternative path between the combustion chamber and a section of the exhaust path downstream of the filter for the products of combustion in the event that the filter becomes clogged;
• a weigh scale supporting the support, the combustible material thereby being able to be continuously weighed during combustion thereof;
• and
• a controller connected to and controlling the operation of the first and second heater elements.

A furnace for burning a combustible material comprising:

• a combustion chamber;
• a support within the combustion chamber for supporting the combustible material;
• a first heater element within the combustion chamber for burning the combustible material;
• a filter having input and output sides and disposed above the support for filtering uncombusted products of combustion of the burning combustible material, the input side of the filter being in fluid communication with the combustion chamber;
• a second heater element adjacent the output side of the filter for burning the uncombusted products of combustion passing through the filter;
• and
• a bypass path having an inlet in fluid communication with the combustion chamber and an outlet disposed between the filter and the second heater element, the bypass path shunting the products of combustion around the filter to the second heater element and providing an alternative path for the products of combustion from the combustion chamber to the second heater element in the event that the filter becomes clogged.

A furnace having upstream and downstream air flow directions and being for use in analyzing materials, said furnace comprising:

• an enclosure,
• a support within said enclosure for supporting a sample including combustible and uncombustible material;
• a first heater element adjacent said support for initial combustion of the combustible material of the support;
• an uncombusted products flow inhibiting assembly disposed downstream of said first heater element for inhibiting the flow out of said furnace of uncombusted products of the combustible material of the sample;
• a second heater element adjacent to and downstream of said uncombustible products flow inhibiting assembly for secondary combustion of the uncombusted products;
• a bypass path having an inlet in fluid communication with the enclosure upstream of an inlet of the uncombusted products flow inhibiting assembly and an outlet disposed immediately adjacent the upstream side of the second heater element, the bypass path shunting the products of combustion around the uncombustible products flow inhibiting assembly to the second heater element and providing an alternative path for the products of combustion from the enclosure to the second heater element;
• and
• a weight indicating device supporting said support, the sample thereby being able to be weighed before anvil after initial combustion of the combustible material thereof.

A furnace for burning a combustible material comprising:

• a combustion chamber;
• a support within the combustion chamber for supporting the combustible material;
• a first heater element within the combustion chamber for burning the combustible material;
• a flow restrictor in fluid communication with and disposed downstream of the combustion chamber;
• a second heater element having an upstream side directed toward the flow restrictor, the second heater element burning the uncombusted products of combustion passing through the flow restrictor;
• and
• a bypass path having an inlet in fluid communication with the combustion chamber upstream of the flow restrictor and an outlet disposed immediately adjacent the upstream side of the second heater element, the bypass path providing an alternative path for the products of combustion from the combustion chamber to the second heater element.

A furnace for burning a combustible material comprising:

• a combustion chamber bounded by a plurality of walls;
• a support within the combustion chamber for supporting the combustible material;
• a first heater element within the combustion chamber for burning the combustible material;
• an exhaust path interconnecting the combustion chamber with an exhaust port communicating with a surrounding environment;
• a second heater element disposed in the exhaust path and having an upstream side directed toward the combustion chamber, the second heater element burning the uncombusted products of combustion exiting the combustion chamber;
• and
• a bypass path having an inlet in a wall of the combustion chamber and an outlet disposed immediately adjacent the upstream side of the second heater element, the bypass path providing an alternative path for the products of combustion from the combustion chamber to the second heater element.