TÍNH BỀN CƠ KHÍ CHO THÂN VÀ ĐÁY,NẮP THIẾT BỊ THEO TIÊU CHUẨN CHLB ĐỨC AD2000 CODE AD2000 code là bộ qui chuẩn tính toán kỹ thuật của hiệp hội kỹ sư Đức dựa trên những tiêu chuẩn DIN,DINISO để tính toán cơ khí cho thiết bị hóa học (đáy nắp, thân thiết bị)ContentI. IntroduceII. Calculation Method1. Parameter calculation2. Cylindrical Shell 2.1 internal pressure 2.2 external pressure3. End and headII. Example
TRƯỜNG ĐẠI HỌC BÁCH KHOA TP HỒ CHÍ MINH KHOA KỸ THUẬT HÓA HỌC BỘ MÔN QUÁ TRÌNH & THIẾT BỊ MÔN THIẾT KẾ CƠ KHÍ THIẾT BỊ HÓA TIỂU LUẬN ĐỀ TÀI: TÍNH BỀN CƠ KHÍ CHO THÂN VÀ ĐÁY,NẮP THIẾT BỊ THEO TIÊU CHUẨN CHLB ĐỨC AD2000 CODE Nhóm 11: Tên MSSV Tên MSSV Trương Thanh Tiến 61203843 Huỳnh Quang Tiên 61203793 Ngô Đức Phước 61202889 Phan Đình Khoa 61201714 Vũ Văn Dũng 606T3071 Vũ Trung Tín 61203889 GVHD: Nguyễn Hữu Hiếu Content I Introduce II Calculation Method Parameter calculation Cylindrical Shell 2.1 internal pressure 2.2 external pressure End and head II Example I.Introduction The AD 2000 Code of practice for pressure vessels is drawn up by the German Pressure Vessel Association Series • • • • • • • • Equipment, installation and marketing (A) Design (B) Fundamentals (G) Manufacturing and testing (HP) Non-metallic materials (N) Special cases (S) Materials (W) Additional notes (Z) Standard DIN DIN ISO DIN EN DIN EN ISO Ex: - DIN EN 10028 – EN 10028 : Flat products made of steel for pressure purpose - (DIN 2391-1); DIN EN 10305-1; EN 10305-1: Seamless precision steel tubes II Calculation Method Parameter calculation (AD2000-B0) Calculate the length of the shell Symbols and units Design pressure Design temperature Design strength value Safety factor The permissible design stress level in joints Allowances Minimum wall thickness Symbols and units a lever arm mm b width mm c1 allowance for minus thickness tolerance mm c2 wear allowance mm d diameter of an opening, flange, screw mm da outside diameter of a tube, nozzle, flange mm di inside diameter of a tube, nozzle, flange mm dt pitch diameter mm dD average gasket diameter mm e wide side of rectangular or elliptical plate mm f narrow side of rectangular or elliptical plate mm g weld thickness mm h height mm k0 setting characteristic of gasket mm k1 service characteristic of gasket mm l length mm n number p design pressure bar Ps maximum allowable pressure bar Pt test pressure bar r generally radius, e.g transition radius mm s required wall thickness includin allowances mm se actual wall thickness mm v factor indicative of the use of the allowable design stress in joints or factor allowing for weakening x decay-length zone A area mm2 mm Calculate the length of the shell -L=H (shells have fit flange and connected with two flat ends) - L = H + h/3 (shells connected with two eliptical or spherical ends) L=l (b < 0,1L) L = l-b (b ≥ 0,1L) (shells have stiffener ring) C, β design factors D shell diameter mm Da outside diameter e.g of a cylindrical shell mm Di inside diameter e.g of a cylindrical shell mm E modulus of elasticity at design temperature N/mm2 F force N I planar moment of inertia mm4 K design strength value at design temperature N/mm2 Kd dimensional stability of sealant at room temperature N/mm2 K20 design strength value at 20 °C N/mm2 M moment N mm R radius of curvature mm S safety factor at design pressure S´ safety factor at test pressure SD leak safety factor SK safety factor against elastic cupping at design pressure S'K safety factor against elastic cupping at test pressure SL safety factor on the permissible number W section modulus mm3 Z auxiliary value v Poisson’s ratio s stress N/mm2 u, T temperature °C of load cycles Design pressure • P> PS ρgh < 5%p => P=Pm ρgh ≥ 5%p => P=Pm+ ρgh • If a pressure-bearing wall is subject to pressure on both sides at the same time, the design shall generally not be based on the pressure difference • If a pressure-bearing wall is subject to pressure and vacuum at the same time, the design pressure is equal to the pressure difference Design temperature - Tmax < 20 °C => T = 20 °C Type of heating Design temperature - Tw < 10oc => see AD 2000Merkblatt W 10 by gases, steam the maximum temperature of the heating medium - For unheated walls: T = Tmmax in the case of protected walls, the maximum working temperature plus 20 K or liquids - For heated walls: - In the case of brick linings, it shall be determined by calculation or measurement by fire, exhaust gas or electrical equipment in the case of directly heated walls, the maximum working temperature plus 50 K Step :Check permissible pressure Internal pressure : The maximum pressure allowed of torisphecal ends: pzul K 40.( se − c1 − c2 ) .v S = Da − ( se − c1 − c2 ) The maximum pressure allowed of knuckle and hemisphere connection : 40.K v.( se − c1 − c2 ) Pzul = Da p.β Safety factor: •The safe factor Sk against elastic buckling of the end under external pressure : •if PT>1,3p: 0, 002 Sk = + Se − C1 − C R S ' K 2.2 ≥Sk External pressure : The safety factor Sk shall be used to examine whether there is adequate safety against elastic inward buckling this is the case where : E se − c1 − c2 pa ≤ 3.66 ÷ Sk R 3.2 Conical shells subjected to internal and external overpressure •Scope s − c1 − c2 0, 001 ≤ ≤ 0,1 Da1 Equation (1) shall be satisfied for s = s1 and for s = sg In the case of external overpressure the opening angle is limited to −70 ≤ ϕ ≤ 70 o o (1) Choose material •Design temperature T •Design pressure P •Outside diameter at effective stiffening Da1 Safety factor Safety factor S shall be taken from tables and of AD 2000-Merkblatt B In case of stressing by external overpressure the safety factor according to 4.1 shall be increased by 20 % The safety factors for grey cast iron remain unchanged The safety factors to prevent elastic and plastic inward buckling of the cone shall be taken from AD 2000-Merkblatt B Calculate minimum thickness S’ •Conical shell is : s’=2mm •Conical shell made of aluminium and its alloys is s’=3mm •Exception to the requirement of 9.1 and 9.2 are possible as specified in 10.2 of AD 2000merkblatt B0 Calculation required thickness s •Tapler length (inside the tapler area ) : x1 = Da1 ( sl − c1 − c2 ) x2 = 0, x3 = 0,5 x1 Da1 ( sl − c1 − c2 ) cos ϕ • Required wall thickness outside of taper area : sg = Dk p + c1 + c2 K 20 .v − p cos ϕ S •Requires wall thickness inside of taper ares : p S sl = 15.K v is required where : Dk : design diameter Dk = Da1 − sl + r ( − cos ϕ ) + x2 sin ϕ Shallow convergent conical shells ( > 70°) 'For shallow conical shells having a knuckle radius r> 0,01 Da1, the required wall thickness is: III Example Thank you for your attention [...]... wall thicknesses 2.1 Cylindrical shells subjected to external overpressure (AD2000- B6) Scope - Da/Di ≤ 1,2 - In the case of tubes with Da ≤ 200 mm => Da/Di ≤ 1,7 Calculation steps Determine minimum thickness S’ ? Choose actual thickness Se ? Check permissible stress ? Choose material ? Calculate stiffener ring ? Step 1: choose material • Design temperature T • Design pressure P • External diameter... 2l lm = bm + b = 1,1 Da ( Se − c1 − c2 ) + b 2.2 Cylindrical and spherical shells subjected to internal overpressure (AD2000- B1) Calculation steps Minimum wall thickness S’ ? Choose actual thickness Se ? Required wall thickness S ? Choose material ? Check permissible stress ? Step 1: Choose material • Design strength value K (N/mm2 ) • Safety factor S • Wall thickness tolerances C1 (mm) • Wear allowance...Design strength value • design temperature : W series of the AD2000 • time-dependent design : AD2000- S 6 Safety factor • The safety factors shall be taken from Tables 2 and 3 unless differing or additional data are given in the individual AD 2000-Merkblätter Allowances • For austenitic... Ceamless, welded or brazed cylindrical shells => S’ = 3 mm • Cylindrical shells made of aluminium and its alloys => S’ = 5 mm • Heat-exchanger tubes, S’ < (3 or 5) mm Step 3: Calculate actual thickness Se Choose Se ≥ S’ Ex: Se = 5 mm Design calculations for elastic buckling 3 2 Se − c1 − c2 S − c − c E 20 80 2 n − 1 − ν 2 e 1 2 . P1 = + n − 1 + (1) 2 2 2 2 Sk Da 12(1... thicknesses) • Seamless, welded or brazed cylindrical shells => S’ = 3 mm • Cylindrical shells made of aluminium and its alloys => S’ = 5 mm • Heat-exchanger tubes, S’ < (3 or 5) mm Step 3: Actual thickness Se Choose Se ≥ S’ (mm) Step 4: Required thickness S •Da /Di ≤ 1,2 or Da ≤ 200mm Da /Di = 1,7 () Cylindrical : Spherical : Da p s= + c1 + c2 K 20 .v + p S Da p s= + c1 + c2 K 40 .v + p S