Liquid management still operations guide

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Liquid management still operations guide

Postby warramungas » Sat Sep 23, 2017 6:31 pm

Liquid Management still operations guide.
(McBOKA, NIXON STONE, OFFSET HEAD, etc)

Contents.

1. Safety

2. Introduction and Theory

3. Normal Operational Instructions
a) Distilling water
c) Ethanol

4. Unit Cleanup

5. Troubleshooting Table



1. Safety.

The LM still has some safety issues that you need to be mindful of. Nearly all these issues are inherent in most stills.

The copper or stainless metal may have sharp edges on it especially around the top and bottoms of any large diameter lengths of pipe.

Be cautious of the sharp edges as much as possible but when inserting packing or assembling/disassembling these components be aware there may be some sharp edges that could lacerate your hand or fingers present. If you find any it is recommended that you remove them if possible.

The copper scrubbers may or may not come with a manufacturers warning as to be aware of sharp edges or ends.
I have not personally encountered any problems but please be aware of it when removing or replacing scrubbers.

Caution: During and after operation the unit may be very hot.
These units operate using highly heated vapor and being made of copper conducts it very efficiently. The Liquid adjustment needle valve may also be hot during and after operation so please use a cloth or a glove when adjusting it.

Ethanol leaks are highly flammable and may burn with a flame invisible to the naked eye.
Especially relevant if you are using gas to power your boiler. If you follow correct assembly instructions the risk will be extremely low but will always be present. It is best practice to keep naked flames away from your unit if you can.
Always check for and rectify any vapour or liquid ethanol leaks as soon as the unit is up to temperature if there a re any present. DO NOT tolerate them during a run. A small hand mirror moved slowly around the joins can show the presence of vapour leaks if/when it fogs up. If you can detect a strong smell of alcohol find the source of the leak and fix it even if it means you need to shut it down and let it cool before you do so.

Pressure may build and the Still may blow out any couplings if the system becomes enclosed.
The cooling coil cap, if fitted, at the very top of the column, should have at least a small hole in the top of it to allow the pressure inside to obtain equilibrium with the outside atmosphere. If obstructed pressure changes could blow the fittings apart during heating or crush the still and boiler during the cool down period. Never, for any reason, obstruct that hole.

2. Introduction and theory.

The home distillation unit was designed and built so that home hobbyists could use it to either create pure water or distill alcohol using the same unit.
Units for sale commercially are usually not built for maximum efficiency or speed using simple distillation theory and therefore were not efficient or fast. You could spend days distilling a single batch using an expensive unit and still only achieve 90% maximum purity.
The requirements of building an efficient and convenient unit are very simple:

1. The unit should be built almost entirely out of copper or stainless.
Copper is used by most commercial distilleries because of its excellent heat conducting properties and its ability to remove some sulphur compounds that contribute to off tastes in the end product. Stainless steel units do not have this property and as such the taste of the final product normally has a distinctive stainless steel ‘bite’ to it. This ‘bite’ can be alleviated by putting copper in the vapour path.
A still composed entirely of copper, including the scrubber packing, ensures maximum removal of any sulphur compounds.

2. The packing should be composed entirely of ‘scrubbers’ or stainless packed mesh.
Mesh Packing provides the maximum amount of area for the alcohol vapors to come into contact with to ensure proper condensation and cleaning properties.
Units that use raschig rings or marbles inside their columns will not provide enough area for condensation of the vapours without much longer columns.
A still that is entirely packed with copper scrubbers allows maximum surface area for condensation or re-cleaning.

3. The Distillation unit should be able to employ Liquid Management principals to allow ease of adjustment and maximum purity.
Liquid Management principals allow easy and simple adjustment of purity regardless of what the power input to the unit is within reason.
This normally consists of a conveniently placed take off valve for the Ethanol that ensures all liquid except for the amount being collected gets returned to the column for further cleaning. The reason this is important is it allows you to adjust the purity of the product takeoff by simply adjusting the valve rather than trying to adjust your power which is a more complex and expensive (purchase of power controllers) adjustment to make.
A needle valve on the liquid takeoff allowing finite adjustments and I sthe preferred valve for small adjustments.

4. The column should be insulated if possible.
Not only does this help prevent accidental burns during operation it also can help increase the columns efficiency by reducing passive reflux down the walls of the column. This saves you energy and gives better ‘bang for your buck’ for your heat input. This is not a necessity and some columns work quite well without it.

5. The column should be long enough to allow maximum cleaning at full power.
The longer the packed column the harder you can run the power and takeoff meaning you can distill with high purity at a faster rate. Fractionating columns can be more than a meter long to allow vapor management where what is boiled is taken at 96% without any product valves adjustments.
The Still column is long enough to allow 96% takeoff at full power with adjustments to the needle valve. Very long columns are unwieldy and difficult to set up in a house so a still that uses Liquid Management can create a shorter, more manageable column.

6. The cooling system should be able to handle full power.
The Cooling coil of the Still should handle up to 2400 watts which is the maximum power most 10 amp switches in regular Australian homes will handle. This way you have some versatility in your stills power input. Most 2” stills will struggle to not flood much beyond 2400 watts.
A power controller like an SSR is a great addition to most still styles and will add infinite different levels of power input to the boiler. Most people cannot recommend highly enough the addition of a power control unit to most still types and is a fantastic addition to a 2" LM or boka style still.
Water addition to the condenser is usually fed into whichever line on your unit goes to the bottom of the condenser the fastest. This gets the coolest water to the bottom where it can do the most work while expelling the hot water from the top.

7. The Distillation unit should have a dedicated cooler for the product.
This allows accurate measurement of the product at reasonable temperatures and minimizes vaporization of the product when collected at just under boiling temperature. Without this component you cannot accurately measure your product without somehow cooling it down first and the liquid coming from the takeoff will be extremely hot and a vapour hazard. The water that feeds the product cooler is usually fed through the bottom, out the top and into your reflux condenser so you do not require individual taps to control either condensing/cooling unit.
The still should come with, or have installed, an efficient, yet simple, product cooler as standard.

8. The Unit should be easy to assemble and disassemble.
The Still is better off being all push fit, bolted, flanged or clamped for the major components. This allows easy assembly, disassembly and cleaning of the unit. Also if it’s a big solidly soldered together unit it can make storage difficult.

3. Normal Operational Instructions

a) Distilling Water
b) Ethanol


a) Distilling Water

1. After correct assembly start your boiler and set it at maximum power (up to 2400 watts). The starting water should be reasonably clean and chemical free.
2. Open your product takeoff valve fully and fill your lines with the cooling water.
3. Monitor the column and temperature. When the column starts to heat up near the liquid management head turn on the thermometer. The temperature will start to come up very quickly when the water reaches boiling point.
4. Start your cooling water. The amount required will vary for each differently powered boiler. Best way to tell if you have enough is to feel the waste water coming out of the waste hose. It should be fairly warm to the touch but not too hot to put your fingers under.
The product will be hot but the product cooler will cool it to a perfectly manageable level.

b) Ethanol

There are two methods for effectively distilling neutral ethanol and one for flavoured spirits and I will endeavor to share them both.

Method 1: Best for a single neutral run. Much slower than Method 2.

1. After correct assembly start your boiler and set it at recommended power if you have power control (1500 to 2000 watts) up to a maximum of 2400 watts. The starting wash should be reasonably clear.
2. Close your product takeoff valve fully and fill your lines with the cooling water.
3. Monitor the column and temperature. When the column starts to heat up near the liquid management head turn on the thermometer. The temperature will start to come up very quickly when the wash reaches boiling point.
4. Start your cooling water. The amount required will vary for each differently powered boiler. Best way to tell if you have enough is to feel the waste water coming out of the waste hose. It should be fairly hot to the touch but not too hot to put your fingers under.
The product will be hot leaving the head but the product cooler will cool it to a perfectly manageable level.
5. Allow the column to stay in equilibrium for 10 minutes or so. The temperature on the thermometer will hover around 76 to 80 degrees Celsius.
6. Open the valve to take full flow out of the liquid management head and remove about 50 to 100ml of heads. This will contain any Methanol if there is any in your product. Sugar washes contain very little Methanol.
7. Close the valve again until your column reaches equilibrium again, could be 15 to 30 minutes, then slowly open the product needle valve until the temperature on the thermometer starts to rise then back it down a tiny bit to maintain temperature.
The temperature beginning to rise indicates that this is your limit before the product strength will start to drop off. You can of course remove product at higher temperatures which will give quicker removal of the alcohol from the wash at lower strength with more impurities.
8. Start collecting the ethanol in small jars or clean empty stubbies so you can make your cuts which are covered in other topics in the beginners section.
9. When the temperature starts to rise on the thermometer without your interference with the needle valve it indicates the wash has had most of the alcohols removed and you are getting into the tail end of the run. You can either back off the product takeoff and try to recover it slower or open it up and remove it all for a quick run to redistill the tails later on.
10. Once the measured strength drops below 20% strength the power and water required removing the alcohol becomes very uneconomical and you should shut down the Still. Turning off the cooling water a minute or two after the power has been shut off will ensure very little steam escapes the top of your column while it is cooling down.

Method 2: Best method for Vodka or neutral spirits. Faster overall than Method 1.

1. After correct assembly start your boiler and set it at recommended power if you have power control (1500 to 2000 watts) up to a maximum of 2400 watts. Can be more power if your cooling coil is efficient enough to knock down all the vapour without flooding the column. The starting wash should be reasonably clear.
2. Close your product takeoff valve fully and fill your lines with the cooling water.
3. Monitor the column and temperature. When the column starts to heat up near the liquid management head turn on the thermometer. The temperature will start to come up very quickly when the wash reaches boiling point.
4. Start your cooling water. The amount required will vary for each differently powered boiler. Best way to tell if you have enough is to feel the waste water coming out of the waste hose. It should be fairly hot to the touch but not too hot to put your fingers under.
The product will be hot leaving the head but the product cooler will cool it to a perfectly manageable level.
6. Open the valve to take full flow out of the liquid management head. We are now commencing the stripping run where we run as fast as we can down to 20% abv coming out of the still.
7. Save all the strip in one container until we have enough strip to do a single spirit run at or below 40% abv. This may take 2 to 4 strip runs combined depending on your boiler size, starting abv and the amount of strip collected.
8. When you have enough to fill your boiler at or below 40% abv, follow the steps in Method 1.

Method 2 does sound slower but it saves time overall than doing multiple Method 1 spirit runs.

Method 3: Best for flavours like rum or whiskey, grain sugar heads, all grain mashes, molasses washes, etc.

1. After correct assembly start your boiler and set it at recommended power if you have power control (1500 to 2000 watts) up to a maximum of 2400 watts. Can be more power if your cooling coil is efficient enough to knock down all the vapour without flooding the column. The starting wash should be reasonably clear.
2. Close your product takeoff valve fully and fill your lines with the cooling water.
3. Monitor the column and temperature. When the column starts to heat up near the liquid management head turn on the thermometer. The temperature will start to come up very quickly when the wash reaches boiling point.
4. Start your cooling water. The amount required will vary for each differently powered boiler. Best way to tell if you have enough is to feel the waste water coming out of the waste hose. It should be fairly hot to the touch but not too hot to put your fingers under.
The product will be hot leaving the head but the product cooler will cool it to a perfectly manageable level.
5. Open the valve to take full flow out of the liquid management head.
6. Reduce your power down to 1000 to 1500 watts range if you can and take the ethanol off slowly into cuts jars. If starting out and learning your stills 'quirks' and best running practice you should start in the lower power range and can increase if you find your still can handle more power and still give good results.
7. Start collecting the ethanol in small jars or clean empty bottles so you can make your cuts which are covered in other topics in the beginners section.
8. Below about 60% abv you can turn the power all the way up and strip the last of the spirit out of the boiler into a large collection vessel for future runs.


4. Unit Cleanup

After disassembly, run water down through the column to remove any ethanol or off smells clinging to the mesh. If you intend to use the unit again within a few days then you can leave the packing in place for your next run. If you intend to pack the unit away for any length of time you should remove the packing and allow it to fully dry out.
The rest of the unit can be washed in the sink (or with the hose) to remove any excess smells and gunk and allowed to fully dry before packing away.

A unit that is made of copper will naturally tarnish over time. Tarnishing will in no way affect the performance of the Still unit. It can be cleaned back to a shine if you wish by using any commercial copper cleaner or a soft stainless steel metal scourer. Do not use a coarse scourer as it will just destroy the surface.

5. Troubleshooting table
SEE ATTACHED PICTURE

Troubleshooting File.png
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warramungas
 
Posts: 1353
Joined: Sun Oct 18, 2015 9:38 pm
Location: Nor Perth
equipment: 180 litre fermenter x 2
30 liter boiler
PDA-1
2" four plate modular bubbler
2" one meter long LM column
110 liter boiler with 25 liter (max) inline thumper
4" x 4 plate bubble cap still

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