US2976716A

US2976716A - Method of determining wear patterns

Info

Publication number: US2976716A
Application number: US751255A
Authority: US
Inventors: Haven Clark G De
Original assignee: Phillips Petroleum Co
Current assignee: Phillips Petroleum Co
Priority date: 1958-07-28
Filing date: 1958-07-28
Publication date: 1961-03-28
Anticipated expiration: 1978-03-28

Description

March 28, 1961 c. G. DE HAVEN METHOD OF DETERMINING WEAR PATTERNS 2 Sheets-Sheet 1 Filed July 28, 1958 CATALYST FIG. 3

INVENTOR.

C.G. DE HAVEN E WE N T n o K C 2ND COAT 3RD COAT 4TH COAT FIG. 2

ATTORNEYS March 28, 1961 c. G. DE HAVEN 2,976,716

METHOD OF DETERMINING WEAR PATTERNS Filed July 28, 1958 v 2 Sheets-Sheet 2 y CATALYST IN FIG. 5 P76. 6

BARE METAL INVENTOR.

IST COAT C.G. DE HAVEN 2ND COAT By 3RD COAT 4TH COAT A TTORNEVS 2,976,716 METHOD or DETERMINING rArrnnNs Clark G. De Haven, Bartlesville, kla., assignor'to'lhillips Petroleum Company, a corporation of Delaware- Filed July 28, 1958, Ser. No. 751,255

51. 6 Claims. (Cl. 73- 7) I This invention relates to a method for determining erosion.

patterns of wear of surfaces. In a more specific aspect the invention relates to a method for rapidly determining patterns of wear ofvarious surfaceswhen contacted with an erosive medium.

In many industrial applications involving various surfaces such as metal conduits, T connections, stirred reaction vessels, etc., erosive fluids or fluids in motion containing abrasive particles gradually wear down the surfaces of the metal, usually with points of comparatively high erosion being encountered. In order to be able to correct the system for minimizing the points of high erosion or to otherwise counteract the effect of high erosion at these points, it is desirable to determine in advance where the points of high erosion will occur. In this way equipment can be saved and plant production can be increased by anticipating the trouble in advance, thus avoiding costly down-time.

One industrial application in which the wear is particularly serious is in a well known fluidized catalyst cracking process wherein air being introduced to the regenerator vessel flows through a pipe which is substantially horizontal in a portion of its length, and into said pipe is introduced through another pipe a flowing mass of finely divided catalyst which is pickedup by the air and introduced into the regenerator. During the combination of the catalyst and air streams in the pipe leading to the regenerator there is encountered a serious erosion problem near the area of confluence of the two streams. It is extremely desirable to be able to predict in advance where the high points of erosion occur so that additional wear plates can be installed. Moreover, if a rapid method of predicting wear of the surface is available, various bafile configurations can be tested in order to find an arrangement which will minimize the wear.

It is therefore an object of the invention to provide a method for rapidly determining the wear patterns of solid surfaces which undergo wear while being contacted with erosive mediums. Other objects, as well as aspects and advantages of the invention, will become apparent from a study of the accompanying disclosure and drawings.

According to the invention, a surface to be subsequently contacted with an erosive medium is painted with successive uniform coats of paint of contrasting colors separated by transparent coats, and the surface is then exposed to said erosive medium for a period of time sufiicient to wear through at least one of said colored coats. The points of high erosion under the conditions of contact with the erosive medium or fluid are then easily seen by visual inspection.

The invention will be better understood by reference to the following specific examples and the figures which will be discussed in connection with the examples.

Figure l is a vertical section of a portion of a conduit employed for mixing a powdered catalyst with air and transporting the catalyst-air mixture downstream. Fig- 2,976,716 Patented Ma.r.

ice

ure 2 is a plan'view of the portion of Figur'e lfbe'tween flanges showing the pattern of erosion; A portionofthe top of the conduit was cut out and laid face up. This is Figure 3 showing the inside of the'cutout portion of the conduit. Figure 4 is an elevation ofa conduit similar to Figure 1, but the rate of en1argernent. from leftgto right o'f the'm ai'n conduit is more'gradual than in Figure 2.

Figure 5 is a 'view of the bottom half of Figure 4 sh owing the pattern of erosion, and Figured is a view-of'the inside of the top half of Figure 4-showing the patternof p In this example a conduit of the configuration of .Flg-

1 inc 1 having main conduit land catalyst introduction conduit 2 was tested with a finely divided silica-alumina powdered catalyst. Before the test the insideof :theqconduits werepainted with four coatsof paintin contrasting colors, each coat being separated by a clear coat. In the tests the powdered catalyst was flowed in through line 2 at a rate of about 200 pounds per minute, while air was flowed into the main conduit 1 from the left to the right at the rate of about 430 cubic feet per minute. The expanding portion of conduit 1 had a diameter of 2 inches on the small end and a diameter on the large end at the flange in the right of the drawing of 5% inches. The length of conduit 1 between flanges at the top was 15 /2 inches. Conduit 2 had a diameter of 2 /2 inches where it enters conduit 1. After completion of operation for a time sufficient to wear through several layers of paint at various points, the test was discontinued and a top portion of the conduit of Figure 1 was cut out. Figure 2 shows the wear pattern of the inside of the pipe with this top portion removed. Figure 3 shows the wear pattern of the inside of the pipe for the removed portion. This figure is an accurate sketch made from the photograph, as is Figure 2. From this test it was determined that the greatest amount of wear' is at the junction of the catalyst conduit 2 and the main or air conduit 1, as shown by the clear areas in Figures 2 and 3 representing bare metal. Varying degrees of wear are shown elsewhere in the figures. The duration of the run in this example was 1 hour.

Example II In this run the test was eflected in the same manner as in Example I except that the duration of the run was 4 hours. Also, it will be seen that the main conduit 1a of Figure 4 used in this test was much less sharply expanded than the conduit of Figure 1. The wear patterns of the bottom half (Figure 5) and the top half (Figure 6) of conduit 1a shows that the gradually expanding conduit 1a is much superior to the more sharply expanding conduit 1 of Figure 1, sincein 4 hours, instead of 1 hour used in Example I, there waas only a small area worn completely bare.

Although in the test conducted in Example I, the conduit 1 was cut open to observe the results, in most instances, including the tests of the present examples, it is possible to visually inspect the results without cutting open the equipment and thus requiring rewelding. This can be done by inserting appropriate mirrors through one or more of the pipe openings.

While the method has been described as employing successive coats of contrasting colors separated by clear coats, the clear separating coats are not absolutely necessary, but are merely preferred.

Erosive mediums encountered and to which the invention is applicable include moving or flowing gases or liquids, which may or may not carry abrasive finely divided solids: gases containing entrained liquid droplets; and flowing or gravitating solids such as refractory pebbles used in pebble heaters or solid catalyst particles such -in rthe light of .the foregoing disclosurerand discussion without departing from the spirit or scope pr the (disclosure or from .thescope; of vthe .claims.

I claim: v} 1. Amethodfordetermining in advance areas offhigh erosion of a:surface to be contacted by an erosive medium iwhichicomprisespaintingisaid surface with suceessiveiuniform coats of paint of contrasting colors, 1 and exposing said surface to conditions causing erosion by saiderosive medium for a time suflicient to :wear through at least one of said colored coats, whereby the areas of high erosion :are worn through"the most layers of said coats of paint.

2. A method 'of claim 1 wherein 'saicl surface is the inside surface of a conduit.

3. A method for determining, in *advance, areas {of "high erosion-of a surfaceto be con'tacted by an erosive spasms 1 1 4 medium which comprises painting said surface with successive uniform coats of paint of contrasting colors separated by transparent coats, and exposing said surface to conditions causing erosion by said erosive medium for a time sufiicient to wear through at least one of said colored coats, whereby the areas of high erosion are worn through the most layers of said coats'of paint.

4. A method of claim 3 wherein said surface is the inside surface o'f-a conduit.

Azmethod ofclaim .2 wherein theerosive medium comprises a fluid.

6. A method of claim 2 wherein the erosive medium comprises a solid.

References Cited in the file of this patent UNITED STATES PATENTS 1 ,961,333 Burns Iune,5, 1934 FOREIGN 'PATENTS 448,223 sGreatBritain June 4, 1936