Find out how many stainless or copper scrubbers you need to pack your column. Choose the tube, scrubber weight (20, 40, 60 or 100 g) and packing density – the calculator gives the number of pieces, the packing weight and a comparison of all weights.
Scrubbers as column packing
Stainless steel scrubbers are the cheapest and simplest column packing. They have lower resistance than prismatic springs, so they work well in columns for flavoured spirits, in the lower part of the column and as a support layer for springs.
How do I put scrubbers into a column?
Gently stretch each scrubber to the tube diameter and push them in one after another, pressing lightly so that no gaps remain at the walls. Packing them too tightly increases resistance and can cause flooding.
Which weight should I choose?
Smaller scrubbers (20–40 g) are easier to place evenly in narrow 1.5–2" columns. Larger ones (60–100 g) are handy in 2.5–3" columns and for long sections – you need fewer pieces.
How we calculate
Column volume V = π × (d/2)² × h. We assume stretched scrubbers fill the column at about 270 g per litre (copper about 300 g/l, as copper is heavier). This is multiplied by the packing density, divided by the scrubber weight and rounded up to whole pieces.
Frequently asked questions
How many scrubbers fit in a 2" column?
A column with an inner diameter of about 48 mm has about 1.8 l of volume per metre. With standard packing that is about 485 g of stainless scrubbers, i.e. 13 pieces of 40 g or 5 pieces of 100 g.
Why copper scrubbers?
Copper binds sulphur compounds that give the distillate an unpleasant smell. A few copper scrubbers in the upper part of the column or in the head are enough – the rest of the packing can be stainless scrubbers.
How do I clean the scrubbers in the column?
Take the scrubbers out and boil them for 20–30 minutes in water with citric acid, then rinse thoroughly. Darkened copper scrubbers regain their colour in a citric acid or vinegar solution. Do not use chlorine-based cleaners.
How often should copper scrubbers be replaced?
Copper gradually wears away as it binds sulphur. When the scrubbers are very dark and crumble despite cleaning, replace them – usually every dozen to several dozen runs.
Can I combine scrubbers with springs?
Yes. A popular setup is a few scrubbers at the bottom as support with prismatic springs above. You can calculate mixed packing in the column packing calculator.