Jump to content

Dimple Jacketed Steam Kettles


JohnMcD

Recommended Posts

John,

My experience is that dimple jackets work just fine with steam. If you're using a liquid as your heat exchanging medium (like in a cooling application) the liquid can tend to take the path of least resistance through the dimple jacket and not work so well.

Nick

Link to comment
Share on other sites

A well engineered dimple jacket performs well. It works with heating and cooling. May I recommend Custom Metal Crafters and Vendome copper and brass works as a supplier. I make nothing from them but they are my friends and a good value.

Link to comment
Share on other sites

Does anyone have any experience with a dimpled jacketed kettle compared to a smooth jacketed one? Just wondering the + -'s

Thanks,

John

I'm new to the forum but not to this topic so I thought I should share my experience, thanks to all who have contributed to make this such a great resource! There are different dimple jacket constructions which can effect the expected service life of the vessel. The cheaper design consists of 2 plates (thin jacket and heavy kettle wall) spot welded together. The space is pressurized with water which stretches the thinner jacket and creates the void for the steam/water/glycol. I have seen light spot welds pop apart or on the opposite extreme i have seen the spot welding have been too hot and leave a crater in the thinner jacket which later leaks. either way you could have a mess a few years down the road. The other method is a punched and formed jacket which is then welded to the heavier kettle bottom. This method is more costly but the welding is more robust. The best method and by far most expensive is spiral wound half-pipe (I'm sure there will be some disagreement on this). With either, the metal must not be 304 but rather 316 or better because 304 is suseptible to corrosion stress cracking in high temperature (above 180F / 70C) applications which can only be remidied by compete jacket replacement (which usually includes the kettle bottom replacement). I agree that working with a experienced & reputable company aviods a lot of potential issues as they have learned this on someone else's project. Either way ask a lot of questions regarding metallurgy and jacket construction or even ask to inspect the jackets prior to them being insulated and cladded over. I have cutt off many a pretty cladding to find horrifying mess underneath! Also, very important!!! be sure that the field installation includes air vents and vacuum breakers for each jacket zone. Armstrong International makes a nice combined unit I think they call it "TAVB". Or do the air venting manually at the begining of the cycle and open the vent to break the vacuum at the end if the $250 a pop is too much.

Link to comment
Share on other sites

Thanks for the replies, always a source of great info here. Sherman I purchased my still from Vendome worked with Kyle Grant, nothing but good things to say!! Definitly agree with the recommendation. I was also at the class you and Paul did at Limestone Branch in the spring, good stuff. I've been going through the used equiptment sites trying to save a buck or two and wanted to make sure a dimpled jacket would be up to the job.Plan on mostly producing whisk(e)y. Equinox, in the used market what should I look out for, anything obvious? Definetly hard to get a read on some of the guys I've talked to.

Thanks,

John

Link to comment
Share on other sites

John, on used equipment you could get the seller to send photos of the nameplate which could have info regarding the type of metal used. Or if the vessel happens to have a national board number you can track down this info from the national board in Cincinnati. Absent that you could have them perform a pressure decay test on the jacket to verify it is intact. Assuming this is a mash cooker, the operating steam pressure is likely no more than 15 psi / 1 bar and they could test with compressed air at same pressure the 24 hr decay should be zero but there might be some drift due to temperature changes. A hydro (water) test is another possibility, these are typically higher pressure (120% nameplate) shorter duration 1-4 hours, again zero loss. Knowing the vessel history such as previous owner, use/service and whether they had a water treatment program can help making your decision.

Link to comment
Share on other sites

Equinox,

The kettle that I am looking at does have a national board number and they provided me the paper work that goes with it. It shows the jacket to be sa240-304 and the "shelf and the heads" to be sa240-316 and yes it would be used for a mash cooker.

Thanks

John

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...