26 September 2009

Brewery - Part 3

Testing the Rig

Finally, having plumbed together all the pipework and gas-lines, added electrical wiring for the pump and a light, modified the stand to accommodate a taller-than-planned gas-burner, jacketed the 3 vessels, it's time to test the bits and pieces.

As any good programmer will tell, you, first you run your Unit Tests. Then, if they're successful, you run Integration Tests. So the morning was filled with testing the various pieces by themselves.

First the gas burners: I had the good fortune to run into a fantastically helpful gas expert, Brian from Knysna Gas. The moment he heard what I was up to, he leapt into action. When I told him which burners I was planning to use, he immediately said, "No! That's not what you want. You want High Pressure burners!" Dragged me out to the back of the shop, and started cobbling together a high-pressure burner setup out of odd parts lying about. Pretty soon he'd put together a burner that can melt all known Chinese restaurants, and roast an ox at 30 paces. This, together with all its pipework,and a high-pressure gas regulator (the Really Expensive Bit) he just gave to me. I ended-up buying another burner from him, once I saw how effective these are compared to the puny piece of junk I had back home. A thousand thanks to Brian for the bits of kit and the excellent advice!

After testing carefully that there were no gas leaks, I fired-up the burners. "All system ready for liftoff. T minus 5." I had to modify the new burner to fit beneath the boiler -- it's stand was too tall, and not needed in any case, since the bench provides its own support for the boiler.

Next the chiller: Finally plumbed in all the necessary fittings for the coolant water, and was ready for testing. My cooling arrangement is a little unorthodox, reflecting both my peculiar circumstance -- no municipal/piped water supply -- and our on-going shortage of rainwater driving our need to conserve every drop.

Cooling water is drawn from the dam near the house, pumped by the already-existing water-pump and pipework. The stuff that waters the veggie garden. After running through the chiller, the water is allowed to drain of via existing drainage back into the dam. Right now the dam is pretty empty, so the water is not as chilly as it should be with a more reasonable depth of water. At least I could establish that the chiller acts as expected with no leaks. T minus 4.

Next up, a cold-water test of all the pipework and the pump. Far better than testing with hot water and discovering that something leaks! Small hold during countdown, here. The pump is a little washing-machine drainage pump, and really quite weak. It has a couple of significant advantages, though: It will happily pump quite large bits of junk along with liquids, which is a very likely scenario when lautering as the mash is quite likely to initially contain bits of grain-husk. Then, too, it is unperturbed by pumping air, provided it is able to self-prime. The only problem with my setup is that the outlet pipe is a bit long, and dips down from the pump, with the result that the pump is prone to developing airlocks which stop it working. It's a problem easily solved, though, and happily caught during testing and not when I have tubs full of rich, hot wort. T minus 3.

Time to find out how well those burners work! 20l of water at 19C in the HLT (Hot Liquid Tank) took around 30 minutes to heat up to 80C. Not bad going, I thought. Pumping the hot water through all the pipes, back and forth between the HLT and the MLT (Mash/Lauter Tank) also served to clean-out any solvents, oils and odd smells from the pipes and pump.

Here's where I discovered the first needed mods to the system. First, there's a bit of clear "plastic" piping joining some plumbing to the pump inlet, and I have strong doubts about its lifetime. I'll have to find a replacement. Second, I need to add a drainage valve to the bottom-most bits of plumbing. right now I have no way to completely drain the whole system, and I don't particularly want to leave water sitting in the pipes -- especially not in the steel parts of the plumbing.

Still, it all seemed to handle hot liquids quite handily. I also learned that, left to its own devices with the stopcock fully open, the pump wants to drain the MLT far too fast. I guess it will be a bit of a learning experience for me to see just where to set that stopcock for a good flow-rate for lautering.

In the process I also learned that I need to preheat the MLT before thinking about starting the mash: The water drops about 10C in temperature just to warm-up the stainless steel tank! T minus 2.

Finally transferred all the water over to the boiler, and fired up the Really Serious Burner. 63C to a full rolling boil in just 13 minutes. Wow! A whole lot of other little concerns got settled along the way. Despite the effectiveness of the burners, the pipes supporting the tanks are easily up to the job, and they don't get significantly hot during a burn -- at least, not hot enough to scorch the wooden frame. Whilst they do get pretty warm, I can still touch them without fear. I was a bit worried that they might bend under the combination of heat and weight. Of course I still have to test them for a full 60- or 90-minute boil under a full 40litre load! but I can have a reasonable degree of confidence that I'm not inviting a disaster. T minus 1 and counting.

Finally, plugged the chiller onto the (still extremely hot) boiler, plugged in the coolant hoses, and let 'er rip. Incoming water (soon to be boiled wort) at a high 90-something C; water falling out into a fermentation vessel: 24C. Good enough for me, and I was really running the coolant water quite slowly. I stopped the coolant water once I was satisfied that the chiller was working well, as I wanted the hot water to clean out any gunk in the chiller copper-inner before I run real wort through it! I do need to figure out a better way of coupling and uncoupling the chiller from the boiler, though. The way I'm doing it now is quite unsatisfactory, and the brass parts probably won't last very long under current conditions.


Now if Vincent at beerkeg.co.za will get his arse in gear and get me my ingredients, we might even have a liftoff!

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