Food & Beverage BEP

Brewery Applications

•The main problem breweries experience, which affects boiler house operation, is the large peak load demands that occur when large coppers or mash tuns come on line.

•The largest single steam load in a brewery is Wort boiling and can account for up to 30% of the total load. When a Wort boiler comes on line it creates a sudden high peak demand which can cause severe priming and carryover from the boiler.

Steam Accumulator

The steam accumulator stores thermal energy. In practice it does not contain "steam". It contains hot water under pressure and a corresponding temperature that is higher than the system steam pressure and temperature.
The diagram illustrates a pressure drop type accumulator with a valve arrangement to provide steam to the system when a sudden pressure drop occurs on the secondary side of the main pressure reducing valve . This would happen when a sudden peak load occurs. The boiler is operated at a pressure higher than the required system pressure. The main pressure reducing valve reduces the boiler pressure down to the required system pressure.
The accumulator charging valve is a surplussing valve that allows steam into the accumulator as long as the steam from the boiler remains above a set pressure. The steam enters the accumulator and is condensed by the water already in there. If a sudden peak load occurs, the pressure will drop and the charging valve will close.The accumulator discharge valve will open when this pressure drop occurs, allowing water in the accumulator to "flash off" into steam and satisfy the peak load demand.

Mashing

Mashing-In Controls

Mashing-in is the process of mixing hot liquor with the grist before it enters the mash tun. Hot liquor and cold liquor are blended together to achieve a liquor temperature of approximately 70°C. This is evenly mixed with the grist in a mashing-in machine before it enters the mash tun. Blending hot and cold liquors prior to the mashing in process is a common method of providing liquor at the required mashing in temperature.
Other methods are used to provide this mashing-in liquor at 70°C such as passing cold liquor through a heat exchanger. Whatever method is used, a good temperature control system will be required.
A common method to ensure that a correct proportion of liquor to grist enters the mash tun is, to control the rate of flow of the liquor into the mashing-in machine. This is achieved by a "Magflo" type flow meter measuring the liquor flow rate linked to an actuated control valve via a proprietary controller.

Decoction Boiler

In the decoction method of mashing, a proportion of the Wort is drawn off the mash tun, heated up in the mash boiler and then passed back into the mash tun to raise the overall temperature.The mash boiler will be fitted with internal steam coils or steam jackets or both. Depending upon the steam distribution pressure, a pressure reducing set may be required.

A temperature control valve will be required to control the steam flow to the coils and jackets. The signal to the valve will normally come from a proprietary controller to provide the temperature ramps and rests found in the mashing process. Strategically placed air vents should be used to remove incondensible gases, especially where steam jackets are used. When decoction mashing is used, the mash tun itself will normally be fitted with steam jackets and sometimes steam coils. These are required to help maintain the temperature of the Wort within the mash tun, particularly during 'rests'.
Steam will be required at the correct pressure, usually lower than boiler pressure, so a pressure reducing valve station will be required.

Temperature control valves will be required to control the steam flow onto the jackets. These will normally be controlled by a signal from the mash control panel.

- Air vents should always be utilized on the steam jackets.

- FT type steam traps would be the first choice for draining condensate from the jackets.

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Steam Generation Steam Distribution Steam Utilization Condensate Recovery