Access port for a thermogravimetric analyzer furnace

Patent metadata

Field	Value
Publication number	US-11899033-B2
Application number	US-201715827367-A
Country	US
Kind code	B2
Filing date	Nov 30, 2017
Priority date	Dec 1, 2016
Publication date	Feb 13, 2024
Grant date	Feb 13, 2024

Abstract

The analyzer of the present invention is specifically adapted to provide moisture determinations for foods and other agricultural material. It allows the operator to introduce a precise weight of sample into a crucible in a closed furnace in a controlled environment through an access port in the furnace cover. The access port in the cover can be tapered to allow easy access to an underlying aligned crucible and allow an operator to add and remove sample material from the crucible until a precise desired sample weight is reached as measured by a balance within the furnace. The access port is enclosed by an insulated cover after the samples are sequentially placed in the crucibles.

First claim

The invention claimed is:

1. A furnace for a thermogravimetric analyzer, said furnace comprising:
a base including a rotatable carousel having a plurality of apertures for receiving crucibles;
a cover movably coupled to said base for movement between open and closed positions to selectively allow access to said carousel;
a heating element in at least one of said base and cover for heating samples positioned in crucibles; and
said cover including an access port aligned with at least one of said crucible-receiving apertures to allow an operator to position sample material in at least one crucible through said access port when said cover is in a closed position, wherein the access port has an opening that is smaller than the apertures in the carousel that receive the crucibles.

2. The furnace as defined in claim 1 wherein said access port is inwardly tapered from said cover toward said carousel.

3. The furnace as defined in claim 1 wherein said access port is funnel-shaped.

4. The furnace as defined in claim 1 and further including an insulated plug which is positioned in said access port during an analysis.

5. The furnace as defined in claim 4 wherein said plug has a surface facing said carousel which is made of a material resistant to high temperatures.

6. The furnace as defined in claim 1 and further including a control circuit for sequentially moving said carousel to sequentially align successive crucible-receiving apertures with said access port to allow an operator to add samples to be analyzed into multiple crucibles posited in said crucible-receiving apertures of said carousel when said cover is closed.

7. The furnace as defined in claim 1 wherein said access port is dimensioned to allow an operator to add and remove sample material to a crucible positioned in a crucible-receiving aperture with said cover in a closed position.

8. The furnace as defined in claim 7 wherein said access port has an upper opening of from about 1¼″ to about 2″.

9. The furnace as defined in claim 8 wherein said access port has a lower opening facing said carousel of from about ¾″ to about 1¼″.

10. The furnace as defined in claim 9 wherein said access port has a height from about 1½″ to about 3″.

11. The furnace as defined in claim 10 wherein said access port has a height of about 2″.

12. A furnace comprising:
a base including a rotatable disk-shaped carousel having a plurality of apertures for receiving and holding crucibles;
a cover coupled to said base and movable between open and closed positions for selectively allowing access to said carousel;
a heating element in at least one of said base and cover for heating samples to be analyzed placed in one or more crucibles positioned in said crucible-holding apertures of said carousel; and
wherein said cover includes an access port dimensioned to allow an operator to add sample material to a crucible positioned in a crucible-holding aperture of said carousel with said cover in a closed position, said access port selectively aligned with one or more crucible-receiving apertures in said carousel to allow an operator to position sample material in a crucible through said access port, wherein the access port has an opening that is smaller than the apertures in the carousel that receive the crucibles.

13. The furnace as defined in claim 12 and further including an insulated plug which is positioned in said access port when said heating element heats samples in said furnace.

14. The furnace as defined in claim 13 and further including a control circuit for sequentially moving said carousel to sequentially align successive crucible-holding apertures with said access port to allow an operator to add samples to be analyzed into multiple crucibles that are positioned in said carousel.

15. The furnace as defined in claim 14 wherein said access port is inwardly tapered from said cover toward said carousel.

16. The furnace as defined in claim 15 wherein said plug has a shape conforming to said access port and has a surface facing said carousel which is made of a high temperature resistant material.

17. The furnace as defined in claim 16 in combination with a plurality of crucibles made of aluminum foil and positioned in said crucible-receiving apertures.

18. A thermogravimetric analyzer comprising:
a furnace having a base and a cover pivotally coupled to said base for movement between open and closed positions, wherein said base includes a carousel with a plurality of circular crucible-receiving apertures having one of two different diameters for receiving a plurality of crucibles positioned in said apertures of said carousel;
an access port formed in said cover and selectively aligned with one of said crucible-receiving apertures to allow a sample to be positioned from outside of the furnace into said one of said crucibles through said cover when said cover is in a closed position, wherein the access port has an opening smaller than an open mouth of the crucibles;
a heating element in said furnace;
a temperature control circuit for controlling the application of power to said heating element;
at least one temperature sensor positioned in said furnace for detecting the furnace temperature;
an electronic balance in said furnace for weighing said one of said crucibles in the carousel; and
a computer coupled to said temperature sensor and to said temperature control circuit to correlate temperatures during a cycle of operation of said furnace through increasing temperature steps to develop and store temperature control signals for controlling the application of power to said heating element, wherein the computer is coupled to said electronic balance to weigh said one of said crucibles throughout the cycle of operation to analyze the sample.

19. The thermogravimetric analyzer as defined in claim 18 wherein said access port is inwardly tapered from said cover toward said carousel to allow sample material to be added and removed from a crucible.

20. The thermogravimetric analyzer as defined in claim 18 wherein said plug has a shape conforming to said access port and has a surface facing said carousel which is made of a high temperature resistant material.

21. The furnace as defined in claim 12 and further comprising a plurality of crucibles positioned in said apertures of said carousel, wherein the access port has an opening smaller than an open mouth of the crucibles.

22. The furnace as defined in claim 1 and further comprising a plurality of crucibles positioned in said apertures of said carousel, wherein the access port has an opening smaller than an open mouth of the crucibles.

Assignees

• Leco Corp

Inventors

• O'Brien Larry S

Classifications

• G01N5/025 Primary

  for determining moisture content · CPC title

• F27B17/02

  specially designed for laboratory use · CPC title

• F27D1/1858

  Doors · CPC title

• G01N25/02

  by investigating changes of state or changes of phase; by investigating sintering {(investigating or analysing oils or hydrocarbon fluids by measuring cloud point or pour point G01N33/2811)} · CPC title

• G05D27/02

  characterised by the use of electric means · CPC title