Overcoming the top four pumping challenges of the brewing and distilling industry
The many challenges faced throughout the brewing or distilling process can be divided into three major areas: raw materials handling, production and waste handling. In each, accurate control of product flow is essential to ensure the final product quality is consistently high. Pumps are therefore integral to brewing and distilling operations. Here, Peter McGarian, managing director at Seepex UK, demonstrates how switching to a progressive cavity (PC) pump can deliver efficiency, productivity and energy gains to help brewers and distillers thrive.
1. Grist mixing and transfer: The brewing or distilling process starts by mixing milled grain with water in a mash or lauter tun, where the starch is converted into sugar. In newer or smaller breweries, the grist case often sits below the mash tun, with a conveyor system transferring the grist to the masher. This involves high incremental costs and can add complexity to the conveying system, leading to mixing problems; water is often added unevenly, resulting in a mix that is not homogenous and reduces the yield.
An alternative to complex conveyor systems are PC pumps in Seepex’s BT range. These offer installation and mashing-in flexibility, allowing the grist to be mixed with hot water and then pumped into the mash tun. Comprising a feed hopper and an auger feed screw, the pitch and diameter of the auger can be adjusted for optimal product feed, ensuring a homogenous mix and a stable yield.
2. Yeast handling: A critical process for any brewery or distillery is the fermentation stage; when yeast is added to the wort to convert simple sugars into alcohol. Yeast is shear-sensitive so requires very gentle and hygienic handling to avoid damaging it.
Peristaltic pumps are sometimes used at this stage, but their pulsating action can have a negative effect on the quality of shear-sensitive products like yeast. By contrast, Seepex’s BCF range of PC pumps offers more gentle and hygienic handling, better preserving the yeast quality for fermentation. This is because PC pumps move the product through the pump in a series of cavities, which prevents slip from the discharge back through the pump. Slip creates shear, so compared to other pump designs which have clearances between the lobes, screws or gears, PC pumps have a very low shear action. They are also good at handling entrained air and foam; important for brewers and distillers as the yeast can gain a foamy consistency at this stage.
At the end of the fermentation process, yeast can also be recovered for re-use by discharging from the conical base of closed vessels or skimming from the surface of open vessels. In either case, the low shear characteristics of the BCF range offer advantages over alternative pumped methods or inefficient manual procedures.
3. Flavour and colour dosing: The addition of flavours and colours into beers and spirits must be done accurately and constantly to ensure even distribution and a consistent final product, with any additives metered in a non-pulsating manner. Positive displacement pumps are sometimes used but their pulsating action means that once they have dispensed a product, there is a pause before they can dispense again. This results in a gap in the process, which can cause uneven distribution of ingredients.
In contrast, Seepex’s PC dosing pumps (D range) are virtually pulsation-free and their output is directly proportional to the rotational speed of the pumping elements. This linear accuracy enables easy calibration and control. Their ability to meter very low flow rates means that colours, flavours and portions are all consistent, and they can also accurately meter a wide range of product consistencies.
4. Removing spent grains, draff and hops: By-products of beer and spirit production include spent grains, draff and hops. At the end of the mashing process, they need to be transferred rapidly to storage tanks or silos to enable production to continue.
The methods of removing spent grain or draff vary according to the size of the brewery. Small breweries favour manual removal, whilst larger breweries or distilleries tend to use compressed air units (pneumatic expeller units). However, brewers and distillers can significantly reduce their costs by pumping these residual materials instead. Open hopper PC pumps with auger feed systems can transport the spent grain or draff within a closed pipe system over hundreds of metres.
Seepex’s Smart Air Injection (SAI) technology is also ideal for this application. SAI can efficiently convey 15-40% dry solids (ds) spent grains, draff and hops in plugs of 20-30m length, over distances of up to several hundred metres using controlled air pulses. SAI combines progressive cavity pumping with pneumatic dense-phase conveying to increase process efficiency and productivity, as well as reducing energy consumption.
In conclusion, by moving away from traditional and inefficient product handling methods towards innovative, problem-solving PC pump solutions, brewers and distillers can maintain their product quality, reduce their energy consumption and increase their production capacity.
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