US2610107A

US2610107A - Combustion analysis apparatus

Info

Publication number: US2610107A
Application number: US139045A
Authority: US
Inventors: George M Dreher
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-01-17
Filing date: 1950-01-17
Publication date: 1952-09-09
Anticipated expiration: 1969-09-09

Description

p 1952 G. M. DREHER COMBUSTION ANALYSIS APPARATUS Filed Jan. 17, 1950 INVENTOR QEaRaE M. DREHER VB 1 Y M Mf ATTO RN Patented Sept. 9, 1952 @171 UNITED STATES PATENT OFFICE l r i 2,r1o,107 I COMBUSTION ANALYSIS APPAn 'r s George M. Drcher, Pittsburgh, Pa.

Application January 17, 1950, SerialNo.139,045

My invention relates in general to combustion apparatus for use in chemical analysisand in particular to a novel combustion tube which may be used in the determination of the carbon and sulphurjcontent of iron or steel.

As part of the apparatus usedin making such determinationit is customary to employ a combustion tube of suitable refractory material, inside of which tube, one or more refractory liners areplaced and inside one of the liners a boat of refractory material containing the sampleto be analyzed is positioned. The tube is located with a portion thereof inside a heating furnace which may be aigas furnace or an electric furnace.

V In determining carbon and sulphur content of a sample of iron or steel, it is customary to place the sample 'in a boat made from refractory material, which boat is placed inside a liner of refractory material, and the boat and liner are placedinside a combustion tube. The assembly is placed ina suitable furnace so that a portion of the assembly may be heated to a temperature say'of theorder of 2500 F.', while a. suitable gas, usually oxygen, is passedthro'ugh the assembly and over the sample and into the determination apparatus.

Heretofore ithas been the practice to us a combustion tube of uniform diameter throughout, or for at least the major portion of its length. When an uncovered boat is used, it is good economy to protect the tube by, also using a liner which extends along the boat and is long enough tocover the boat, and small enough in diameter to be readily inserted in and withdrawn from the tube. The liner protects the tube from spattering slag, and when sufficientslag or other foreign. material collects onits internal surface, it may be replaced.

,The main purpose of this invention is to provide a combustion tube of improved construction which is particularly adapted to the use of a replaceable liner. To this end, the portion of the tube which is positioned within the furnace is.

provided with a depression in its lower internal surface in which a cylindrical liner may be placed. The depression has shoulders at its ends which are spaced apart a distance slightly greater than the length of the liner and which thus act to hold the liner in position to prevent accidental displacement of the liner in the tube. In a manner which will be described, the liner has a wall thickness substantially the same as the depth of the depression so that its internal surface constitutes a continuation of the internal surface of the inlet 4 Claims. (01. 23-253) end portion of the tube whereby a combustion boat may slide freely to and from a position within the liner. The liner thus need be moved or replaced only when suflicient dirt has accumulated I on its interior surface as will interfere with move- It is another object of my invention to provide a combustion analysis tube which has a boat whichhas a shaped bottomto correspond with the inner wall of the liner in which it is placed.

It is stillanoth'er object of my invention'to provide a combustion analysis apparatus of such proportions that the volume of gas employed'is a convenient minimum.

It is a further object to provide a combustionanalysis appara'tusin which the tube, the liner and the boat are so proportioned that the various needed manipulative steps may be performed and the tube so proportioned asto permit the use of a relatively low volume of gas.

It is a still further object to provide a combustion analysis apparatus which is simple, inexpensive, accurate, and which will enable relatively low cost determination of the chemical constituents of a material sample to be mad by combustion analysis.

1 In the accompanying drawings, wherein I have shown the presently preferred embodiments of my invention:

Figure 1 is a view in vertical section of a conventional heating furnace showing my improved tube,liner and boat assembly in operative posi: tion in the furnace;

Figure 2 is an enlarged vertical sectional view of the apparatus along the line 11-11 of Figure 1;

Figure 3 is an enlarged vertical sectional view along line III-III of Figure l; and

Figure 4 is an, enlarged vertical sectional view along line IV-IV of Figure 1.

In the drawings, the reference numeral I0 designates a combustion furnace of known construction having a combustion chamber ll surrounded by insulating walls I! of any suitable refractory material. A combustion tube H formed of any suitable refractory material, passes horizontally through the end walls of the furnace and through the heating or combustion chamber II. The tube 14 extends for a desir able distance beyond the end walls to provide at one end an inlet end l6, and at the other end a discharge portion or exit end Between the tube end portions there is a bulge or an enlarged portion N3 of greater cross sectional depth than is the inlet portion l6, which in turn is of a cross section greater than that of exit portion IT.

The upper wall of inlet portion I6 and enlarged portion iii are in the same plane, while the lower portion offthe inner wall of enlarged portion I8 is in a plane below that of the lower portion of the inner wall of inlet portion l6, when the tube is in a horizontal position. The right-hand end of the bottom of the enlarged portion or bulge I8 is connected to the bottom of the-inlet portion I8 by a shoulder 20 which extends part way round the junction of the portions as seen in Figure 3. The difference in levels of the bot- Y toms of the inner walls is substantally equal to the thickness of asrefractoryliner- 2|;which is shown in operatingxposition in the shell of the enlarged portion I8.

The exit portion ll of. the combustion tube is of asection less'than that of the enlarged por-; tion I8, and forms at the junction with portion I8, an annular shoulder 22. There is; thus pro.- videda central portion l8 which is larger in diameter than is the inlet portion, I6 and still larger than is the exit portion As representative dimensions, the inlet portion l6 mayhavean inner diameter of about /4 of an inch, while the exit portionmay have an inner diameter of about inch to, about '7 inch. The liner 2| may be conveniently about 4," long, of cylindrical form, with an outside-diameter of about of an inch and a uniform wall thickness of the order of about of an inch. The inner diameter of the enlarged portion l8 could well be. of the order of to inch, and the lengthof about ll/g-inches long enough to receive the liner 2 The'various dimensions are such, that. the, liner may be. moved through the inlet portion IE to the chemical determination position, in the enlarged center portion |8'. When the liner is placed in position between the shoulders and 22, it will remain there until it is purposely moved by means of a manipulative device, such as a hooked wire. The shoulders 20 and, 22 prevent accidental displacement.

The dimensions I have set forth are those of a desirable apparatus. But the measurements are exemplary only, and the dimensions adopted .may be more'or less as the operator desires and convenience necessitates.

I place in the liner 2| a boat 25 which I prefer to make with a'bottom portion 26 shaped so as to conform to the lower portion of the inner wall of the liner. The boat has straight sides 24, and which extend to a position close to the side walls of the liner, and the ends are sloped outwardly and upwardly as shown in Figure'l. A handle 21 with an eye 28 therethrough extends to the right as shown in Figure 1. By means of a hooked wire which may be connected to this eye, the boat 25 may be moved into or out of its position inside the liner 2|, which is located when in operation in the enlarged portion Hi.

In the determination operation, the boat 25 with its chemical sample must bermoyed along the lower wall of .the inlet portion. and into'p0-' sition in the liner as shown in Figure 1. For this purpose it is highly desirable that the bottom portion of the inner wall of the liner 2|. should be-at least as low and. preferably slightly:

from the liner in position in the enlarged portion l8 without dimculty. The height of the walls of the boat should be such as'can be readily inserted in the liner, and it must be remembered that the dimensions of the various portions of the 'appa'ratusmust be such'as v'villmake allowance for the variations in the finished dimensions of the various refractory articles comprising the apparatus, which by the nature of their manufacture, cannot be assuredly held to precise measurements.

In operation, the tube M is mounted in position within the furnace as illustrated in Fig. l.

A liner 2| is then placed in position within the enlarged portion |8 of the tube M with its ends positioned between the shoulders 20 and 22 at the ends of the enlarged portion |'8 so that such shoulders'operate to prevent accidental endwise movementof the liner 2 The furnace maythen. be --operated to bring the portion of the tube within the furnace and its liner 2| up to operating temperature. The combustionboatlii may then be slid over the bottom surfaces of the in.- let end portion I6 of the tube and'liner- 2| to aposition within the liner 2|. The lower internal surface of the liner 2| being in substantially the same plane as the lower internal surface of the tube IS, the insertion. and removal of the boat 25 may be effected without diniculty. The liner, of course, need bev placed only when sufficient slag has collected on its internal surfaceto interfere with the flow of oxygen through the liner or the removal and replacement of the combustion boat; The dimensions of theparts', particularly the size.

of the enlarged portion 8 with respect. to the in.- let end, portion l6 and the outlet end portion I1 and the formation of the end l! with a smaller diameter than the inlet end it, is, particularly designed? to maintain the, internal, volume of the. tube at a minimumwhile facilitating the removal and replacement of both the liner 2| and the combustion tube25.

While I have described the presently preferred embodiment of my invention, it is to be known that changes and, modifications. may be made within the scope of the following claims.

I claim:

1. In combustion analysis apparatus including having inlet and outlet end portions extending through said walls and a center portion posi-- tioned in said chamben'said centerportlon having on its lower internal surface a depression providing shoulders spaced from each other axially of the tube, and a cylindrical protective liner having a length slightly less than the spacing of said shoulders for insertion in said tube to a position in which said shoulders act as abutments for preventing axial displacemet of the liner out of said depression, said liner having a wall thickness and said depression having a depth-which are substantially equal so'that the bottom internal surface of said liner in'efl'ect constitutes a continuation of the bottom internal surfacev of one of said end portions whereby a' I 2. The invention described in claim 1 charac terized by said central portion, having a diameter.

greater than either of said end portions to facilitate removal of said liner from said central portion.

3. The invention described in claim 2 characterized by said one end portion being the inlet portion, and said outlet portion having a diameter less than the diameter of said outlet portion to thereby reduce the space in said tube to a minimum.

4. In combustion analysis apparatus including a heating furnace having insulated walls defining a heating chamber therein, a combustion tube having inlet and outlet end portions extending through said walls and a center portion positioned in said chamber, said center portion having the bottom portion of its internal surface depressed below the level of the bottom portion of the internal surface of said inlet end portion to provide a shoulder between said internal surfaces, an abutment at the other end of said depressed center portion and a cylindrical liner having a (length slightly less than the distance between said shoulder and abutment for insertion in said tube to a position lying on said depressed center portion, said liner having a thickness and said depressed center portion having a depth which are substantially equal so that the bottom internal surface of said liner constitutes a continuation of the bottom internal surface or said inlet end portion whereby a combustion boat may slide freely over said internal surfaces in its removal from and insertion in said liner.

GEORGE M. DREHER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Yensen Nov. 11, 1924 Dreher Aug. 14, 1945 Number

Claims

1. IN COMBUSTION ANALYSIS APPARATUS INCLUDING A HEATING FURNACE HAVING INSULATED WALLS DEFINING A HEATING CHAMBER THEREIN, A COMBUSTION TUBE HAVING INLET AND OUTLET END PORTIONS EXTENDING THROUGH SAID WALLS AND A CENTER PORTION POSITIONED IN SAID CHAMBER, SAID CENTER PORTON HAVING ON ITS LOWER INTERNAL SURFACE A DEPRESSION PROVIDING SHOULDERS SPACED FROM EACH OTHER AXIALLY OF THE TUBE, AND A CYLINDRICAL PROTECTIVE LINER HAVING A LENGTH SLIGHTLY LESS THAN THE SPACING OF SAID SHOULDERS FOR INSERTION IN SAID TUBE TO A POSITION IN WHICH SAID SHOULDERS ACT AS ABUTMENTS FOR PREVENTING AXIAL DISPLACEMET OF THE