Friday, 5 February 2016

Guinness’s Park Royal Brewery in 1949 – the brew house (part three)

We’re gradually making our way through the Park Royal brew house, and have now reached the coppers.

“There are four wort coppers each with a holding capacity of 650 barrels. They are designed for pressure boiling at about 1.5 Ib. p.s.i.g., giving a wort boiling temperature of about 216° F. The coppers are steam heated, being fitted with a six-wing vertical tubular heater having a heating surface of 176 sq. ft. and a five-loop heating coil with a surface of 160 sq. ft. arranged at the bottom of the copper. Steam is supplied at a pressure of 100 p.s.i.g., being reduced steam from the high-pressure steam lines. Each copper heater unit is capable of heating up a full copper in 1.5 hours, and is capable of boiling off a maximum of 30 barrels per hour. Steam consumption is of the order of 9,000 lb. of steam per hour on the maximum duty. The copper is fitted with the usual pressure control and vacuum breaking and striking-off valves.”
Journal of the Institute of Brewing Volume 55, Issue 5, 1949, page 282.

You can see that the capacity of the coppers was matched to that of the mash tuns. If you were aiming at getting 600 barrels in the fermenters, 650 barrels seems the right amount to put in the copper, allowing for the boil off of some liquid. A standard boil was around 1.5 hours after WW II, which means around 45 barrels would evaporate during the process. Again fitting in neatly with my numbers.

Fuel economy during the war led to a redesign of the copper:

“Originally the copper domes were bare copper in accordance with general brewery practice, but during the war the domes were lagged with 2.5-in. magnesia with a saving in fuel of approximately 150 tons of coal per annum.”
Journal of the Institute of Brewing Volume 55, Issue 5, 1949, page 282.

In a way, breweries should have been pleased with the drive to save fuel during wartime. Because it led to permanent cost savings. As with lagging the coppers. I assume by magnesia they mean the same plastic magnesia that was used to insulate the mash tuns.

The coppers were one of the differences between Park Royal and St. James’s Gate:

“At the time Park Royal was being designed, the coppers in the Dublin brewery were coal fired with the exception of one which had been fitted with a steam heater for experimental purposes. From the brewers' point of view, brewer colleagues appear to be quite satisfied with the result of steam heating—at least they have not yet asked for the steam heaters to be taken out in order to revert to coal or oil firing.”
Journal of the Institute of Brewing Volume 55, Issue 5, 1949, page 282.

I wonder if they eventually fitted all steam heaters to all of the coppers in Dublin?

And what did they do with the steam coming off the coppers?

“The vapour from boiling off is led through a lagged vapour main to jet condensers, specially designed for the purpose, and the cooling water is normally that returning from the wort refrigerators at a temperature of 130° F., which is just below the critical temperature for the deposition of the temporary salts. If, however, boiling off is taking place at a time when the wort refrigerators are not in use, direct cold water is used. In either case, the supply can be regulated automatically to give the condensate a temperature of 205° F., or the condensate re-circulated over the condenser to raise its temperature. The condensate is run down to the brewhouse low receivers for use in the brewhouse liquor system. Each copper has its unit condenser, which can deal with the maximum rate of reduction of 30 barrels per hour. The jet condenser is a simple and less costly plant than the more usual surface condenser, but it can only be used where a use can be made for the mixture of cooling water and condensed steam, i.e. distilled water. A brewery, of course, can make good use of such a supply of hot water.”
Journal of the Institute of Brewing Volume 55, Issue 5, 1949, page 282.

In this sense, a refrigerator is a specific piece of equipment used for cooling wort. The classic device has a series of copper pipes through which water flows. The wort flows over the top of these pipes. The water returning from the device would have been heated by the wort if was cooling. So obviously they didn’t need cold water for this purpose.

This is another area where Guinness saved money through energy-saving measures:

“The factors determining design are quantity and temperature of the cooling water available; the quantity and temperature of the steam or vapour to be condensed and the temperature of the condensate required, the latter being variable depending upon the amount of cooling water used or available. Conserving the heat of the copper reduction vapour in the way adopted saves approximately 750 tons of coal per annum.”
Journal of the Institute of Brewing Volume 55, Issue 5, 1949, page 282.

Hop backs next.

No comments: