When it comes to beer bottling, it is important to maintain a balance between fluid movement and pressure. If the pressure is slightly higher than the fluid movement, the bottle may burst. On the other hand, if the fluid movement is greater than the pressure, it will force the cap to pop open. But how can you make sure that your beer bottles maintain the perfect balance between pressure and fluid movement? Liquid ring pumps!
What are liquid ring pumps?
Liquid ring pumps are positive-displacement pumps that use suction pressure to maintain the volume of an object. If the object is the beer in the bottle, a liquid ring pump will make sure that it maintains the pressure and volume of beer and not pop the cap out suddenly. This type of pump works in tandem with a sealant to ensure that the object doesn’t crack open or burst when in transit. The sealant can be any type of liquid, such as water or oil.
Something to keep in mind during beer bottling is that the overall temperature shouldn’t dip below the boiling point. Liquid ring pumps don’t perform well at low temperatures, and there is a risk of the bottles breaking or the sealant not working. Additionally, it also leads to bioactive components accumulating at the bottom of the pump, thus increasing the risk of contaminating the beer.
Working principle of liquid ring pumps
Think of the liquid ring pump as a cylindrical body with an impeller attached to the housing of the pump. Now, how do you create the vacuum with the impeller? First, you need the sealant. Here, the beer is sufficient since it already contains water. You need to fill the pump with the sealant before you start using the liquid ring pump. Make sure you fill at least a quarter of the total volume of the cylinder.
Most liquid ring pumps have a closed-loop system through which the sealant can recirculate, thus reducing the wastage of beer while bottling. Once you start the pump, the impeller uses its centrifugal force to sling the sealant on the cylinder’s outer wall. Repeated use of centrifugal force creates a ring of liquid at the top of the bottle, and that’s the moment when you need to press the cap onto the bottle. The pressure and the liquid movement remain balanced if you manage to fit the bottle’s cap at the right time when the pump creates the liquid ring on top.
One of the factors that makes liquid ring pumps unique is that some of them can remain immersed underneath the sealant, while others can stay out of the sealant and work flawlessly. It’s up to you how you will use the pump and your preferred system of bottling beer. These pumps seal off the space between the impeller’s blade and the sealant to ensure that the latter recedes from the central hub of the pump, thus allowing the pump’s piston to create a larger cell. Once the piston creates a larger cell, it draws air, vapor, or gases through the impeller’s blades to maintain the bottle’s pressure.
Types of liquid ring pumps
- Single-stage liquid ring pump
- Two-stage liquid ring pump
Usually, the beer bottling process requires a single-stage liquid pump. This type of pump can use its suction pressure in a single revolution and slowly release the pressure to seal the bottle.
On the other hand, two-stage vacuum pumps have two parts: in the first part, a pump discharges its suction port to the second pump, which later maintains the balance between liquid movement and pressure of the bottle. Although a two-stage ring pump provides higher vacuum levels, it is not suitable for beer bottling as it takes more time to seal the bottles.
Why use liquid ring pumps in beer bottling?
Most pumps are useful for vacuum creation and pumping operations, but liquid ring pumps are essential for compressing gas or vapor, thus making them ideal for beer bottling. It uses its impeller rotating mechanism to compress vapor inside the bottle. That’s why you will notice beer bottles emitting a small amount of vapor when you pop the caps open.
Moreover, these ring pumps can efficiently handle condensable vapor and fluids at the same time. This ensures that the quality of beer doesn’t deteriorate even if you shake the bottle multiple times before opening it. The pump makes sure that the vacuum, liquid movement, and pressure remain intact to allow you to enjoy the beer’s taste.
Although liquid ring pumps are popular in bottling beer, you will find them in other industries also, such as aircraft, petroleum, concrete, automobile, and water treatment.