Thumper spear clog?

[BlueJ]

I have a 15.5g keg and a 7.5g keg thumper running on electric. Today it was charged with about 8g of clear mash and the thumper with about 2g of murky corn meal from the bottom of the fermenter. I set this up in a cold garage last night and it sat overnight to run today. During heat up, I got normal action in the boiler and a few pings from the thumper, then the thumper stopped making noise. It does quite down once up to temp so I didn’t think too much of it, but all the sudden Ingot a huge loud “whoosh” from the boiler column I to the thumper and it immediately started to bubble and quickly boil in the thumper. I added a sight glass to this run so I could see the vapor rushing up the column like it was shot out of a jet engine for about 3-4 seconds. My butt puckered up something fierce. Running absolutely fine and normal now.

I think maybe the sitting overnight and the first few hot bubbles of vapor from the boiler dried up the corn mash in the thumper and sort of made a biscuit at the end of my spear? Is that possible? Then the pressure built and pushed through the clog. My spear has holes and cuts around the bottom to disperse vapor. Not sure what I did wrong here.

Anyone experience this and have suggestions. I read one thread that said the little holes could get clogged but I would think the 1” pipe open at the bottom of the spear would not.

[shadylane]

I've made that mistake before.
The pressure buildup blew the water out of the manometer.

[BlueJ]

Certainly not something I want to happen again. So do you dilute the trub before adding to the thumper or just not add them and let it sit overnight like I did? Or both? I don’t think the consistency of the trub changed in the thumper overnight. Maybe the small amount sitting inside the spear dries out?

[BlueJ]

After more searching on the site, found this old post. viewtopic.php?t=69301
The warnings in this post about not loading your thumper too far ahead were something I hadn’t run across in many years of reading and studying this site and hobby and something I didn’t think would be an issue. Copying here so maybe it saves someone else from having a small problem grow into a catastrophic one. Now on to researching pressure relief valves.

[Dancing4dan]

I think Eric's silicone tips might have saved you. Doesn't seem like it would allow grain to get into the steam leg and cause a plug. I am going to try his idea next steam distill.

Also good idea to stir prior to fire up.

[dukethebeagle120]

I have a 15.5g keg and a 7.5g keg thumper running on electric. Today it was charged with about 8g of clear mash and the thumper with about 2g of murky corn meal from the bottom of the fermenter. I set this up in a cold garage last night and it sat overnight to run today. During heat up, I got normal action in the boiler and a few pings from the thumper, then the thumper stopped making noise. It does quite down once up to temp so I didn’t think too much of it, but all the sudden Ingot a huge loud “whoosh” from the boiler column I to the thumper and it immediately started to bubble and quickly boil in the thumper. I added a sight glass to this run so I could see the vapor rushing up the column like it was shot out of a jet engine for about 3-4 seconds. My butt puckered up something fierce. Running absolutely fine and normal now.

I think maybe the sitting overnight and the first few hot bubbles of vapor from the boiler dried up the corn mash in the thumper and sort of made a biscuit at the end of my spear? Is that possible? Then the pressure built and pushed through the clog. My spear has holes and cuts around the bottom to disperse vapor. Not sure what I did wrong here.

Anyone experience this and have suggestions. I read one thread that said the little holes could get clogged but I would think the 1” pipe open at the bottom of the spear would not.

From experience,I find it safer to heat up main boiler.
Once you got steam,attach the arm between the main and the thump keg..
Leaving it sit to long causes blockage
Starr heat back up.
Give the thump keg a shake once in a while to keep things moving.
This is how I do it.
Others may differ opinion.
That's ok

[BlueJ]

Thanks for the help. Heating up prior to closing up the thumper and stirring make sense to me. I understand the concept of the silicone tip on the spear, but everywhere on this site the advice is to not use silicone gaskets and opt for PTFE. How is this silicone tip considered safe to use? Not a criticism, generally confused and like the idea if it is commonly accepted.

[Yummyrum]

A silicone teat would be acceptable to use if you are Steam stripping with water in the boiler . The Teat would only be exposed to 10%ABV or less which we consider safe .
However , you put clear Mash in the Boiler and slops in the Thumper . The ABV coming out of the Boiler and passing through the Teat could be 50% aBV or higher particularly at the start of the Run This is a lot higher than we would consider safe .
There is not a Pass/Fail limit to Silicone but rather an increasing risk as the ABV and temperature increase.

[NormandieStill]

Also just a side note, but having been looking at the silicone tips in the hope of replicating the great successes here, the only ones I can find that are rated high-temp and fit the description are not listed anywhere as food-grade. Which is normal seeing as powder coating is not generally a food safe process... at least, you don't cook in the same place as you're powder coating. I can probably find some high-temp silicone which is food safe (oven gloves / baking sheet) but not in the forms that make those tips so useful.

TL;DR even with water in the boiler, those tips may not be safe for distilling use.

[zach]

I've kept the spear in the fermenter from mashing through steaming. Before distilling with steam I put some air pressure through the spear to verify I have a clear path. I have a 1/2" Tee with two bazooka screens for ends.

I run my rig outside, so during boiler warm up I leave a valve open to atmosphere. When I hear the whistle, I close the the valve and direct the steam to the thumper. I watch the boiler pressure gauge and listen for the thumping sound to verify it working properly.

When I clean up after a run I do have some grain inside injection point but have never experienced a clog. I have 1/2" psi vacuum breaker which in theory would allow the boiler to suck grain up the spear on power failure during a run. But in practice I open the valve to atmosphere when the power goes out to avoid any suck back up the spear.

[BlueJ]

This is a lot higher than we would consider safe.

Yummy and Normandie- that is what my initial thoughts were. To each there own but I think I’ll stick with not preloading the thumper too early, a good stir and waiting for pressure from the boiler as suggested above. Thanks everyone.

[Tōtōchtin]

Silicone rubber compound is inert and not known for leaching. They use the same material in plugs for lab equipment, not that means crap. But I doubt they would use it in a lab if it was known to leach. They are marketed up to 300*C. I plan on heating up my grain mashes using them. 10% and 90*C is well within the limits but I did email the company to see what their compound mix is. I'll get back if they reply.
Tōtō

[Yummyrum]

Silicone rubber compound is inert and not known for leaching. They use the same material in plugs for lab equipment, not that means crap.

If it was inert then these Silicone Rubber teats on our Dropper bottles would not have disintegrated .

Silicone rubber is not compatible with all Chemicals .

[Tōtōchtin]

Silicone rubber compound is inert and not known for leaching. They use the same material in plugs for lab equipment, not that means crap.

If it was inert then these Silicone Rubber teats on our Dropper bottles would not have disintegrated .

IMG_0077.jpegIMG_0078.jpeg

Silicone rubber is not compatible with all Chemicals .

There are different high temperature silicone rubber compounds, which is why I sent an email to ask. You can't chuck it all into one label. I have some setting in some 96* caña for a week now. I weighed out the pieces and liquid . I'm ll check it out in a month if I don't hear back from the manufacturer.

[BlueJ]

I understand many folks use these for steam stripping where I guess the tip is immersed in 10% or so mash and is hit with H2O steam. I have no scientific background, but that seems different from what I am using the thumper for which is the traditional doubler - pushing sometimes 100-140 proof distillate through the spear into the thumper contents. Maybe I am wrong (and I am sure someone will tell me if I am), but could the tips be safe for H2O steam stripping and not for regular thumper runs.

[BlueJ]

Well just re-read the above and I think this is basically what Yummy said… sometimes it takes me a bit longer to get things through my thick head.