Liquid Surface Ball

A liquid surface covering ball is a hollow plastic ball made to float on top of a liquid and, together with thousands of its neighbours, to form a floating lid over the surface. Each ball is light and hollow, so it rides high, and it is shaped to sit steadily rather than roll, so the balls settle into an even, close-packed layer that covers most of the surface — the covering rate runs from about 91 to as much as 99 percent. That floating layer is what does the job. By capping the surface it slows evaporation, traps rising fumes and acid mist beneath it, keeps heat in, and shuts out much of the air that would otherwise dissolve into the liquid and spoil it. Add more balls and they simply top up the layer; there is nothing to install and nothing to fix in place.

The covering ball is used wherever an open liquid surface causes trouble. Its classic home is the acid storage tank, upright or horizontal, where it holds down the acid fog that would otherwise escape into the air; it is used the same way on electroplating and water-treatment tanks and on condensate and desalination tanks. The point in each case is to cover a surface that is evaporating, fuming or picking up carbon dioxide and oxygen from the air. Doing so protects the liquid, cuts loss and fumes, saves the energy that evaporation and heat loss waste, and keeps the working environment cleaner. Anywhere a volatile or corrosive liquid stands with an open top, a floating layer of these balls helps.

The ball is moulded from polypropylene, a light, tough, corrosion-resistant plastic, which is why it copes with the acidic and aggressive liquids it usually floats on — it will sit on strongly acidic solutions, down to around pH one, without being attacked. It works at temperatures up to about 120 degrees and barely takes up any water, so it keeps floating. It comes in two densities, roughly a third and a half the density of water, so it always floats but can be matched to how much wind or disturbance the surface sees, and in sizes from 20 up to 80 millimetres. Tell us the liquid, its temperature and the tank size and we will suggest the size and density.

It looks like a ball, but its job is the opposite of a tower packing or a bio ball. A tower packing is dumped inside a column to spread gas and liquid over its surface for absorption or distillation; a bio ball is a carrier that holds a biofilm in a treatment tank. The covering ball does neither — it floats on top of a still liquid and simply caps it, to stop what is below from evaporating, fuming or reacting with the air. So it is not sized for gas-liquid contact or biofilm area but for coverage: how completely a layer of balls blankets the surface. If you need to fill a scrubber or grow biofilm, this is the wrong ball; if you need to cover and protect a tank of liquid, it is the right one. Send the tank details and we will confirm.