[Shell & Tube Exchanger] Pulling bundle Calculation

[Shell & Tube Exchanger] Pulling bundle Calculation (API 660 & TEMA)

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1. API 660 Para 7.3.1 Shell Supports

 

When the support of a removable-bundle heat exchanger is fixed to the shell, it shall be designed to withstand a longitudinal force equal to 150 % of the bundle mass applied at the heat exchanger bundle centerline. The shear stress for supports shall not exceed 40 % of the yield strength of the material.

 

Removable bundle 설계일 경우 bundle 을 shell 에서 분리할 때 bundle 무게의 150% 를 감안하여 support 설계를 진행하여야 한다.

 

2. TEMA G-7.1.1 Horizontal Unit

 

For units with removable tube bundles, supports should be designed to withstand a pulling force equal to 1-1/2 times the weight of the tube bundle.

 

Horizontal units are normally provided with at least two saddle type supports, with holes for anchor bolts. The holes in all but one of the supports are to be elongated to accommodate axial movement of the unit under operating conditions.

 

API 와 같이 bundle weight 의 150% 를 고려하여 support 를 설계하여야 한다.

 

3. 결론

 

Bundle removal 을 고려하여 pulling load 계산 시 bundle 의 150% weight 를 감안하여 support 및 foundation bolt 설계가 이루어져야 한다.

 

1) bundle pulling load = 1.5 x weight x u (friction factor)

2) pulling 을 위한 tubesheet 에 eyebolt 또는 pulling lug 설치

3) 운전 시에는 plug 로 마감하고 bundle 분리 시 eyebolt 설치

4) fixed side 의 stress 계산 수행

- shear stress / Bending stress / Compressive stress for saddle

- Stress at anchor bolt on fixed side

- Eyebolt strength