1、AUTOMATED CRUSH STRENGTH OF EXTRUDED CATALYSTS UOP Method 973-01 SCOPE This method is for determining the crush strength of extruded and shaped catalysts using a Chatillon motorized sample stand and force gauge with a chisel anvil. The measurement range is from 1 Newton (N) (0.22 lbf) to 250 N (56 l
2、bf). The range can be extended to 450 N (101 lbf) when using an alternative force gauge. Test apparatus other than the Chatillon may be used provided comparable data can be obtained. For statistical purposes, the number of extruded pieces crushed is set at a minimum of fifty; however, more may be sp
3、ecified. Data generated using this method cannot be directly compared to those generated using UOP Method 914, Automated Crush Strength of Catalysts or Molecular Sieves. This method will yield higher values for crush strength. Proper comparisons can only be made after tests are run to determine the
4、offset between the two methods. Such offsets are expected to vary from product to product. OUTLINE OF METHOD A representative sample is riffled to obtain approximately, but not less than, fifty extrudates. This riffled sample is treated at 500C (930F) in a dish for one hour and then transferred in t
5、he dish to a hot plate set at 200C (400F) to avoid moisture pick-up. Each extrudate is placed on a flat plate at a perpendicular orientation to the chisel attachment that is 1 mm across at the contact point. It is then subjected to a compressive load, and the force required to crush the extrudate is
6、 recorded. The procedure is repeated until a minimum of fifty extrudates in the riffled sample have been crushed, and the average crush strength per extrudate is calculated. The percent of extrudates having a crush strength above or below a given value (product specification or customer driven) can
7、be reported, as well as the maximum and minimum crush strength for individual extrudates within the set. In addition, the crush strength data can be graphically displayed as a histogram. Results can be reported in either Newtons (N) or pounds-force (lbf) as measured using a 1-mm chisel. APPARATUS Re
8、ferences to catalog numbers and suppliers are included as a convenience to the method user. Other suppliers may be used. Brush, round, camels hair, Fisher Scientific, Cat. No. 03-670 IT IS THE USERS RESPONSIBILITY TO ESTABLISH APPROPRIATE PRECAUTIONARY PRACTICES AND TO DETERMINE THE APPLICABILITY OF
9、 REGULATORY LIMITATIONS PRIOR TO USE. EFFECTIVE HEALTH AND SAFETY PRACTICES ARE TO BE FOLLOWED WHEN UTILIZING THIS PROCEDURE. FAILURE TO UTILIZE THIS PROCEDURE IN THE MANNER PRESCRIBED HEREIN CAN BE HAZARDOUS. MATERIAL SAFETY DATA SHEETS (MSDS) OR EXPERIMENTAL MATERIAL SAFETY DATA SHEETS (EMSDS) FOR
10、 ALL OF THE MATERIALS USED IN THIS PROCEDURE SHOULD BE REVIEWED FOR SELECTION OF THE APPROPRIATE PERSONAL PROTECTION EQUIPMENT (PPE). COPYRIGHT 2001 UOP LLC ALL RIGHTS RESERVED UOP Methods are available through ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken PA 19428-2959,
11、United States. The Methods may be obtained through the ASTM website, www.astm.org, or by contacting Customer Service at serviceastm.org, 610.832.9555 FAX, or 610.832.9585 PHONE. 2 of 6 973-01 Calibration weights, Class 3, Fisher Scientific, Cat. No. 02-225-26P Computer, personal, for running Chatill
12、on software, and capable of running Excel, Minitab or similar software to develop a histogram and perform post-analysis calculations, JLW Instrument Dish, porcelain, Coors 60230, Fisher Scientific, Cat. No. 08-693A Forceps, blunt-pointed, straight, 127-mm length, Fisher Scientific, Cat. No. 08-890 H
13、ot plate, capable of 200C Muffle furnace, capable of 500C Printer, any model compatible with the computer Riffler, Fisher Scientific, Cat. No. 04-942D Sieves, wire cloth, brass frame, 8-inch diameter, 2-inch depth, U.S. Standard sieves Nos. 8, 10, 12, 16, 20, and 30, Fisher Scientific, Cat. Nos. 04-
14、881F, G, H, K, M, and P, respectively; with cover and pan, Fisher Scientific, Cat. Nos. 04-886A and B, respectively. The sieves meet current ASTM E 11 and ISO 565/3310-1 specifications. Software (optional), Minitab or other equivalent for displaying histogram, and Excel or equivalent for post-analys
15、is calculations Software (required), Chatillon, AutoTest, to control TCD-200 and collect data from DFA50/100 Surface temperature probe, Spot Check Thermometer, PTC Instruments, Model 573F Test stand and gauge, Chatillon, includes Cat. No. TCD-200 Motorized Test Stand, Cat. No. DFA50 Turbo gauge incl
16、uding 1 x 6-mm chisel anvil tip, Cat. No. DFA100 Turbo gauge (optional), JLW Instrument Tongs, crucible, Fisher Scientific, Cat. No. 15-207 Tray, utility, stainless steel, 420- x 250- x 64-mm, Fisher Scientific, Cat. No. 13-361C REAGENTS AND MATERIALS References to catalog numbers and suppliers are
17、included as a convenience to the method user. Other suppliers may be used. Reference catalysts, extrudate, the same types as samples routinely run, UOP PROCEDURE The Chatillon instrument manual must be thoroughly understood before operation or calibration. The instrument must be validated per Chatil
18、lon instructions. Read and understand DFA50, or DFA100, force gauge limits, and TCD-200 operational settings, overloads, etc. 3 of 6 973-01 It is recommended that the user select one or more extrudate reference catalysts, similar to those being analyzed, for weekly quality control evaluation (in wee
19、ks when samples are being analyzed). Sufficient reference material should be obtained to last for at least six months, preferably one to five years. The reference should be well riffled and stored in sealed containers to reduce moisture absorption. The reference data obtained can be used to develop
20、a control chart that is valuable in detecting analytical variations. Validate instrument performance per the manufacturers instructions monthly when samples are being analyzed, or when indicated by rule violations, trend shifts, or out of control SPC data. Instrument validation is accomplished by in
21、verting the force gauge and placing known weights on the platform and reading the applied force on the gauge LED. The gauge should be sent to the manufacturer or approved representative yearly for calibration and certification. Weight calibration tolerances: 0.5 kg: 4.9 0.4 N, 1 kg: 9.8 0.3 N, 2 kg:
22、 19.6 0.3 N. Instrument Setup 1. Set the Chatillon reference point to 18.5 mm, following manufacturers instructions. The reference point and travel distance may vary from site to site. Statistical equivalence must be determined before applying parameter variations. 2. Install the chisel anvil. 3. Se
23、lect the Chisel Alignment program to mark the flush contact point of the plate and chisel tip, see Table 1. Use a pencil to mark a heavy line on the base plate along the front and back long edge of the chisel. If desired, after the force gauge is raised, mark a line perpendicular to the reference ma
24、rk just made. This will help align the extrudate catalyst perpendicular to the chisel point. 4. Run zero position program (Z-RECAL, see Table 1) that is appropriate to the method being used. 5. Select and run appropriate analysis program. Table 1 lists general parameter settings for the Chatillon in
25、strument. Other instrument parameters may be used, based upon the sample type. It is the laboratorys responsibility to show correlation with the general parameter settings. To avoid confusion, the parameters in Table 1 are listed as they appear on the instrument screen. Not all parameters are used.
26、Test code and Test name designations may differ from site to site. Sample Analysis 1. Remove fines and small pieces by placing the sample onto one of the sieves listed in Table 2, depending upon the nominal diameter of the product. Shake gently for one minute. 2. Riffle the screened extrudates down
27、to a sub-sample size of approximately, but not less than, 50 extrudates. 3. Transfer the riffled extrudates to a dish and place in a 500C muffle furnace for one hour. CAUTION: Wear appropriate personal protective equipment and use tongs when transferring dish to the muffle furnace and from the muffl
28、e furnace to the hot plate. Tests have shown that crush strength decreases with increasing sample moisture content. 4 of 6 973-01 Table 1 General Chatillon Parameter Settings Standard Extrudate Zero Recalibration Chisel Alignment Test type # 1 2 3 Test Code UOP-120 Z-RECAL Chisel Test Name Crush Tes
29、t Recalibrate Zero Pt Sample quantity 55 0 0 Xname Deflection X X Xunits mm mm mm Speeds 120 3 3 Home deflection 0 18.3 0.5 Begin deflection -12 0 0 End deflection -17.5 0 0 Yname Force Y Y Yunits N N N Min force 1.5 0 0 Max force 200 0 0 Pollprog Addpol0 Zz-recal Zz-recal Failure -0.7 0 0 Aux value
30、 n/a 0 0 Min x interval -1 0 0 Cycle profile n/a n/a n/a Control profile n/a n/a n/a Table 2 Sieves for Screening of Sample Nominal Diameter (mm) U.S. Standard Sieve No. Below 1.3 30 1.3 20 1.6 16 2.1 12 2.5 10 Above 2.5 8 4. Quickly transfer the dish to a hot plate set at a minimum of 200C. Begin t
31、he crush strength determinations without delay, and continue until the required number of extrudates are crushed. 5. Run the zero recalibration (Z-RECAL) program between each sample to prevent any program problems. 6. Position a hot extrudate at the center of the perpendicular lines using the blunt
32、forceps. CAUTION: Take precautions to avoid burns when picking up an extrudate from the dish on the hot plate. 7. Press “ENTER“ to begin movement of the motor-driven gauge. 5 of 6 973-01 After the extrudate is crushed, the moveable anvil automatically returns to the preset position. 8. Brush the cru
33、shed material from the anvils into the utility tray with the camels hair brush. 9. Insert the next extrudate immediately. 10. Repeat Steps 6 through 9 until a minimum of 50 extrudates riffled from the original sample have been crushed (testing of a larger number of extrudates may be requested). CALC
34、ULATIONS The calculation of average crush strength is pre-programmed into the AutoTest software. Report values to the nearest whole number if in N, or the nearest tenth if in lbf. Multiply the raw N value from the instrument printout times 0.2248 to convert to lbf. Eq. 1 is the manual calculation of
35、 average crush strength. Reports can be configured and saved for later use. SCXM= (1) where: C = average crush strength, N or lbfS = sum of the recorded strengths for all extrudates crushed, N or lbfM = width in mm of the chisel piece used, 1 mm for the stock chisel piece X = number of extrudates cr
36、ushed If requested, calculate the percent of extrudates having crush strength above or below a given value and report to the nearest tenth of a percent using Eq. 2. See the specification for the particular product or customer. PB 100X= (2) where: B = extrudates having a crush strength above or below
37、 a given value, % P = number of extrudates crushed having a crush strength above or below a given value X = previously defined, Eq. 1 100 = factor to convert to percent If further evaluation is required, transfer the data to the personal computer equipped with Excel or Minitab to perform the calcula
38、tions and display a histogram. REPORT Report all values listed below in N to the nearest whole number, or in lbfto the nearest tenth. Average crush strength, as calculated in Eq.1 (or from the instrument printout). Percent of extrudates having a crush strength above or below a given value, calculate
39、d in Eq. 2. Maximum crush strength - choose the highest value from the extrudates crushed. Minimum crush strength - choose the lowest value from the extrudates crushed. 6 of 6 973-01 PRECISION The precision statements were determined using UOP Method 999. A nested design was carried out for determin
40、ing crush strength of three reference extruded catalysts with two analysts in three laboratories. Each analyst carried out tests on two separate days, performing two tests each day for each sample. The total number of tests performed was 72. The precision data are summarized in Table 3. Two tests pe
41、rformed by the same analyst on the same day should not differ by more than the ASTM allowable difference shown in Table 3 with 95% confidence. Two tests performed in one laboratory by different analysts on different days should not differ by more than the UOP allowable difference shown in Table 3 wi
42、th 95% confidence. Two tests performed by different analysts in different laboratories on different days should not differ by more than the Reproducibility allowable difference shown in Table 3 with 95% confidence. Table 3 ASTM and UOP Repeatability and Reproducibility, Newtons ASTM Repeatability UO
43、P Repeatability Reproducibility Sample Mean Within-Day esd Allowable Difference Within-Lab esd Allowable Difference Within-Lab and Between- Lab esd Allowable Difference 1 26 1.0 3 1.5 5 1.8 6 2 41 1.9 6 2.3 7 2.9 10 3 (Trilobe) 28 1.9 6 1.8 5 3.5 14 The data in Table 3 are a short-term estimate of r
44、epeatability. When the test is run routinely, a control standard and chart should be used to develop a better estimate of the long-term repeatability. TIME FOR ANALYSIS The elapsed time for a single analysis is 1.8 hours, with a labor requirement of 0.8 hour. REFERENCES Ametek DFA50 Force Gauge Manu
45、al, included with instrument AutoTest Software Manual, included with instrument Chatillon Instrument Manual, included with instrument UOP Method 914, “Automated Crush Strength of Catalysts or Molecular Sieves” UOP Method 999, “Precision Statements in UOP Methods” SUGGESTED SUPPLIERS JLW Instrument Corp., 452 Nc . Sangamon, Chicago, IL 60622 (312-666-0595) Fisher Scientific, 711 Forbes Ave., Pittsburgh, PA 15219 (412-562-8300) PTC Instruments, 2301 Federal Ave., Los Angeles, CA 90064-1482 (310-312-0826)
