This investigation will be into some physics aspects which occur at the Charles Wells brewery in Bedford. This brewery is the fifth largest in the UK and can hold up to 46,000 pints at one moment. The two aspects of physics I will be discussing in this piece of coursework are the x-rays used to detect how much beer there is in each can, the anti-vac valve and the pressure release valve. The x-ray is used to measure how much beer is in each can. The x-rays are simply sent through one side of the beer can and are collected on the other side which then shows how much of the x-rays have got through the can.
The pressure release valve is used to release the pressure from within the tank to balance out the air pressures so that dents aren’t formed on the tank. The anti-vac valve is used for the opposite, to stop the tank imploding. X-rays The reason that they choose to use x-rays to measure how much beer is in each can is that the beer in the can has the ability to partially absorb the x-rays so less get through to the other side. The way that the x-rays work is that if too much x-rays get through it shows that the can has too little beer contained within it.
On the other hand if the can has just the right amount of beer within it only a few x-rays will be able to pass through. The reason that gamma rays weren’t used is that the beer wouldn’t stop the gamma rays passing through, so it would be completely useless in telling how much beer is in the can. However if they used ultra-violet the opposite would happen as it isn’t powerful enough for the rays to pass through the can so it would again be useless for reading how much beer is in the can as no rays would pass through the can no matter how much beer is in the can. Anti-vac valve
This valve is used to minimise the risk of tanks imploding. This is used for tanks which are exposed to vacuum, this can occur during emptying, cool rinsing after hot-cleaning or caustic cleaning in a carbon dioxide atmosphere. The anti-vac valve is to be placed on any closed tank. The way in which physics is used in this piece of equipment is that if the pressure inside the tanks gets too low then the CWM which is caused by the difference in pressures, the outside pressure being higher then the inside one, will become greater then the ACWM which is the moment of the counter weight.
This then involves the valve opening so that the two pressures equal out with each other, therefore it changes the low pressure inside to get to higher pressure which equals the pressure of the air outside to prevent the tank imploding. This valve is used on any closed tank. Calculations for the anti-vac valve. From the diagram before I know 4 pieces of information to find out what the two moments need to be.
Firstly for the ACWM (anti-clockwise movement) I know that counter weight is 5kg, the gravity is 9. 81 N, the distance from the pivot is 0.3m and for the CWM (clockwise movement) moment I know that the distance from the pivot is 0. 1m. If the ACWM 5kg x 9. 81N x 0. 3m which is equal to 14. 715Nm, from this I know that the CWM needs to equal 14. 715Nm. So to find the CWM I divide the 14. 715 by 0. 1 I get 147. 15N. This is the value that the pressure needs to be coming from outside of the tank to balance these two forces. Pressure relief valve The pressure relief valve is used to help prevent the risk of the tanks getting damaged from causes such as over pressurising or liquid overfill.
The way in which physics is used in this valve is that if the pressure from the carbon dioxide inside the tank is too great then the valve opens to release that pressure so that it doesn’t cause any damage to the tank. For this to happen then the ACWM, which is the carbon dioxide, needs to be greater than the CWM, which is the counter weight moment, this would then allow some of the pressure to escape and return the pressure inside the tank to normal so that the can go back to normal and close: http://www.scandibrew.co.uk/pressure_releif_valve.htm