Curd Settling Tank (Dimple Jacket) is imploded during chilled water circulation

[US Rao]

Dear Friends,

We have been used 5KL, Dimple Jacketed type Curd Settling Tank. The tank will be used for preparation of curd.

The operations in the tank is as follows:

Pasteurized milk will be taken in Settling Tank at 42 Deg. C.
Culture will be added,
Once PH comes down to 4.8, Chilled water will be circulated in the Jacket until the product inside the tank is comes down from 42 to 4 Deg.C. Once curd is formed in the tank, the product will be transferred to other settling tank for preparation of Butter Milk & Lassi.

The tank is having Air Vent at Top of the tank, NRV at chilled water return line, Safety Valve at Chilled water return line before NRV.

Despite of above protections also, product is inside the tank and during chilled water circulation inside the jacket, the tank is getting implosion. As per operator, the tank is getting imploded when the product is inside and the chilled water is under circulation in the jacket.

Photographs of damaged tank is attached attached (Tank and Air Vent)
We are unable to find out the causes for tank implosion. Kindly help us.

Regards
US Rao.

 

[bimr]

bimr, it is simple physics. A vacuum on the outside of a vessel cannot implode it. The vacuum has to be inside.

The point being made is that the vessel is poorly constructed which is the cause for the collapse. The interior tank wall appears to be of inadequate thickness as shown by the indentations of the dimple welds from inside the vessel as shown on picture 4. It may be worthwhile to ask the vessel manufacturer for the design calculations on the vessel.