GB1574735A

GB1574735A - Keg racking

Info

Publication number: GB1574735A
Application number: GB1201677A
Authority: GB
Original assignee: GKN Sankey Ltd
Current assignee: Sankey Holding Ltd
Priority date: 1978-03-16
Filing date: 1978-03-16
Publication date: 1980-09-10

Description

(54) KEG RACKING (71) We, GKN SANKEY LIMITED, a British company of P.O. Box 214, Hadley Castle Works, Telford, Salop TF1 4RF formerly of Albert Street, Bilston, West Midlands do hereby declare the invention for which we pray that a patent be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to the keg racking of beer. During the brewing of beer, carbon dioxide is generated and remains in solution in the beer. When the beer has been brewed it is stored in a buffer tank under a head pressure of carbon dioxide sufficient to retain the carbon dioxide in solution in the beer but insufficient to dissolve any appreciable quantity of carbon dioxide in the beer above that which is present as a result of the brewing process. This head pressure does not normally exceed 30 psig. The beer is then pumped into a keg at a higher pressure of between 80-120 psig. The keg, prior to filling, contains carbon dioxide which is exhausted through a pressure relief valve as the beer is filled into the keg, the pressure relief valve is set to maintain the pressure on the beer entering the keg.

Two problems arise with the racking process as it is at present carried out. The first problem is a reduction in the top pressure of carbon dioxide on the beer as the latter is being filled, the pressure falling below a value required to maintain in solution the carbon dioxide generated during the brewing process.

Thus before the keg is filled with the beer it will have been washed and then sterilized with steam. At the start of the filling operation the keg will be hot and it is then filled with carbon dioxide under pressure. The initial entry of the beer cools the keg and the pressure of the carbon dioxide therein drops and may drop below the value required to maintain the generated carbon dioxide in the beer so that some of this carbon dioxide escapes from the beer and the quality of the beer in the keg is thus affected.

The second problem is the opposite of the first and is the possibility that the pressure of the carbon dioxide in the beer in the keg after it has been filled is higher than is desired.

This over pressurising of the keg can occur due to a slight difference in timing in the beer control valves. Thus the beer passes from the tank through a beer meter which measures the quantity of beer delivered to the keg and then through a beer inlet valve. The escape of carbon dioxide from the keg is controlled by an outlet valve. The valves are, in theory, operated by synchronism when the correct amount of beer has been delivered through the meter. Thus the meter produces an electric closing signal which is passed to two electro-pneumatic valves which operate against springs and these in turn operate pneumatically the inlet and outlet valves.

Because of this manner of operation, one of the inlet and outlet valves may close before the other. If the outlet valve closes before the inlve valve then the last increment of beer delivered into the keg will be at a pumped pressure of, e.g., 80 - 120 psig. and may fill the entire head space of the keg so that the carbon dioxide in the beer will be at a higher pressure than desired and this will cause fobbing on serving until the pressure in the keg has dropped to the desired value.

Both the above problems occur randomly in a racking run so that while some kegs in the run will have beer therein at the desired top pressure, say 15 psig, some kegs may have beer therein at a higher pressure than this and some will contain beer which has lost some of its condition because in the initial stages of filling the top pressure will have dropped below that desired.

It is an object of the invention to provide a method of, and apparatus for, racking keg beer which will result in the beer in the kegs having a more uniform top pressure and condition than heretofore.

According to the invention, we provide a method of racking beer into a keg so that when the keg has been filled with a desired quantity of beer and sealed there will be a predetermined top pressure of gas on the beer, the method comprising initially filling the keg with gas to a higher pressure than said predetermined pressure, supplying beer to the keg while allowing said gas to escape from the keg but maintaining the pressure of gas in the keg at a greater value than said predetermined pressure, terminating the supply of beer to the keg when said desired quantity has been delivered, subsequently allowing the pressure in the keg to decrease to said predetermined pressure and then sealing the keg.

According to this method, therefore, delivery of beer to the keg is terminated first.

Since the gas pressure in the keg will be above that desired, (and will be set to take into account the rise in temperature of the beer due to transfer of heat to the beer from the keg during filling), the pressure in the keg is allowed to decay, the pressure is sensed as it is decaying and when the pressure reaches the predetermined value the keg is sealed. It will be seen that the method will ensure.

assuming that the pressure sensor is accurate.

that all the kegs in a kegging run will have gas therein at the same top pressure.

The invention also provides apparatus for racking beer into a keg so that when a keg has been filled with the desired quantity of beer and sealed there will be a predetermined top pressure of gas on the beer, the apparatus comprising means for filling a keg at a pressure higher than said predetermined pressure. means for connecting the keg to a supply of beer and to a gas exhaust. an inlet means to control entry of beer to the keg. an outlet means to control the escape of gas from the keg as beer is supplied thereto and to control the pressure of the gas in the keg.

means for closing the inlet means independently of the outlet means and means to sense the pressure in the keg and to close the outlet means after the inlet means has closed and when said pressure falls to said predetermined pressure.

Preferably the outlet means comprises a pressure relief valve to control the gas pressure in the keg during filling and means to allow controlled decay of the pressure in the keg after the inlet means has been closed.

Thus the outlet means may comprise a pressure relief valve which can be caused to operate as a fixed orifice through which gas andior beer escapes and which controls the rate at which the pressure in the keg decays after the inlet means is closed.

The pressure relief valve may be converted into a fixed orifice device by a signal generated upon closing of the inlet means.

The connecting means may include a beer meter to meter the supply of beer to the keg and for producing a signal for closing the inlet means when the desired quantity of beer has been delivered to the keg.

Alternatively the keg may be brim filled and the beer meter omitted, the inlet means being closed upon a rise in pressure at the outlet means due to the beer reaching a fixed orifice through which the gas has been exhausted, the orifice causing a greater rise in pressure when operating on the liquid beer than when operating on the gas. This arrangement can also be used with a beer meter as a fail safe arrangement.

The invention will now be described in detail by way of example with reference to the accompanying diagrammatic drawings in which: Figure 1 is a circuit diagram of apparatus embodying the invention; and Figure 2 is a diagram showing a pressure relief valve convertible to a fixed orifice.

Referring now to Figure 1, the keg to be filled is indicated at 10 and a buffer tank to contain the beer is indicated at 11. The beer in the tank 11 is indicated at 12 and is under a top pressure of carbon dioxide. for example 15 psig. The beer is withdrawn from the tank 11 via a conduit 13 containing a pump 14, a beer meter 15 and a beer inlet valve 16. The conduit is connected to a keg fitting indicated diagrammatically at 17 which has a downtube 18 through which the beer is delivered into the keg. The beer is delivered adjacent to the bottom of the keg.

Before the keg is filled. it is washed and immediately before it is filled the keg is sterilized by means of steam supplied through a steam valve 19 connected to a conduit 20 which in turn is connected to the keg fitting 17. The steam enters the keg adjacent to the top thereof. The steam escapes up the downtube 18 into the conduit 13 and then through a steam and gas exhaust valve 21 which in turn communicates with the pressure relief valve 22 which maintains the steam under pressure. On leaving the valve 22 the steam is exhausted.

After the keg has been sterilized, the valve 19 is closed and carbon dioxide is fed to the keg through a valve 23. the carbon dioxide entering the keg along the conduit 20 and driving any condensate out of the keg up the downtube 18 and through the valves 21 and 22. The keg 23 is pressurised to a value of 30-50 psig which is above the final pressure required in the keg after it has been filled and sealed. This pressure is maintained by the setting of the pressure relief valve 22. When the condensate has been removed from the keg and the latter has been pressurized. the valve 23 is closed.

The beer is now fed into the keg via the pump 14, meter 15 and valve 16. As the beer enters the keg, the carbon dioxide therein is exhausted through an outlet valve 24 which communicates via a conduit 25 with a pressure relief valve 26 which will be described in more detail below. The pressure relief valve 26 is set to maintain, during filling of the keg 10, a pressure in the carbon dioxide in the keg which is greater than the pressure desired in the filled, sealed keg. The pressure relief valve 26 may maintain the pressure in the keg at the value of 30-50 psig. The initial setting of the pressure relief valve 22 and the setting of the pressure relief valve 26 are such that the pressure of the carbon dioxide in the keg during the whole of the filling step will be greater than that desired in the sealed and filled keg and great enough to prevent any fobbing during filling even though the beer will increase in temperature during filling due to heat transfer from the keg. This will be so even though the pressure of the carbon dioxide in the keg will decrease upon the initial entry of the beer into the keg. Thus after the keg has been sterilized by the steam and has been pressurized by opening the valve 23, the keg will still be hot and the initial entry of the beer will cool the keg and reduce the pressure therein. If desired, to minimise the pressure drop in the keg upon initial filling, the opening of the valve 24 may be delayed until after the start of the delivery of beer to the keg.

When the desired quantity of beer has been filled in the keg, the beer meter 15 will produce an electrical signal on the line 27.

This signal will open a normally closed double pole switch 28, one pole of which is a line 29 connected to an electro-pneumatic valve 30. The valve 30 is of the changeover type which is operated by a solenoid against the action of a spring and controls the supply of compressed air to the inlet valve 16 and pressure relief valve 26. The opening of the line 29 will de-energise the solenoid of the valve 30 thus closing the valve 16. Furthermore, a pneumatic signal will now pass along the line 31 to the pressure relief valve 26 as will be described below. A line 32 connects the other side of the double pole switch to an electro-pneumatic valve 33 which is connected to a pneumatic line 34 to control the outlet valve 24. The opening of the other side of the double pole switch 28 would, normally, de-energise the solenoid of the valve 33 closing the outlet valve 24. However, there is a line 35 which is in parallel with the line 32 and contains a normally closed switch 36 which is also connected to the valve 33 and maintains the solenoid thereof energised and thus outlet valve 24 open until the switch 36 is opened. The switch 36 is operated by an actuator 37 controlled along a line 38 from a pressure sensor 39 which senses the pressure in the conduit 25.

What happens, therefore, when the correct amount of beer has been delivered to the keg 10 is that the inlet valve 16 is closed. The outlet valve 24 is maintained open since the switch 36 remains closed. The pressure sensor 39 is set to actuate the switch 36 when the pressure in the keg falls to a value equal to that which is desired in the filled and sealed keg. As described, however, the pressure in the keg 10 is maintained, during filling, at a value higher than this desired pressure so that when the inlet valve 16 is closed the pressure in the keg is still at this higher value which is sensed by the pressure sensor 39 and the switch 36 remains closed.

The signal which passes along the line 31 from the valve 30 upon closing of the inlet valve 16 modifies the pressure relief valve 26 to turn it into a fixed orifice valve. The pressure of the carbon dioxide in the keg 10 can escape through the valve 24 and the fixed orifice now provided by the valve 26 and does so until the pressure in the keg'falls or decays to the desired value. This will be sensed by the sensor 39 and this will send a signal along the line 38 to the actuator 37 which will open the switch 36. Upon opening the switch 36 the valve 33 will be deenergised and a signal will pass to the outlet valve 24 which will close so that the keg will now contain the right amount of beer at the desired pressure. Simultaneously with the closing of the outlet valve 24 the ket is sealed.

Carbon dioxide is now passed through the valve 23 and along the conduits 20 and 13 to displace any beer in these conduits, the beer being returned, with the carbon dioxide through a "save" valve 40 to store.

It will be seen that the invention ensures that the filling operation will result in a keg having the right amount of beer therein at the right pressure. The method and apparatus overcome the problems inherent in the previous system of either under-pressure or over-pressure in the beer.

Figure 2 shows the construction of the pressure relief valve 26. The conduit 25 is indicated and the pressure sensor 39 is also shown communicating with the conduit. The valve includes a cylinder 41 in which is slidable a plunger 42 having a needle 43 which co-operates with a seating 44. Secured to the plunger 42 is a piston 45 and a spring 46 acts between an abutment 47 and the piston 45 while the pressure in the conduit 25 acts on the underside of the plunger 42. The needle 43 will co-operate with the seating 44 when the valve is operating normally at the desired pressure which is set by the abutment 47 which is threadedly engaged in the cylinder 41. Air can enter underneath the piston 45 through the line 31 leading from the valve 30 and act between the underside of the piston 45 and a rigid diaphragm 45a extending across the cylinder 41. When a signal is pas sed along the line 31, therefore, the piston 45 is lifted which lifts the needle 43 until an abutment 48 on the needle comes into engagement with a face 49 on a housing. The abutment 48 has an orifice 50 which is of known size and communicates with the conduit 25. It is through this orifice 50 that the pressure in the keg escapes when the keg has been filled.

The invention includes filling the container in an inverted position in which case the beer will enter the lower end of the keg and the gas will escape through the downtube 18.

The invention is also concerned with a pressure relief valve which is convertible to a fixed orifice as described in relation to Figure 2.

In a possible modification to the apparatus above described, the beer meter 15 and the line 27 by which its output signal is applied to the switch 28, may be omitted. In this case, a fixed orifice valve 51 would be incorporated in the conduit which connects the fitting 17 of the keg to the valve 24 and pressure relief valve 26, and a pressure sensing switch 52 connected at a position to sense the pressure upstream of the orifice 51. The switch 52 is connected by a line 53 to the switch 28. to operate the switch 28 when the pressure sensed by switch 52 exceeds a predetermined value.

In operation of apparatus incorporating, this modification, beer being supplied to the keg by pump 14 will brim fill the keg instead of being cut-off when the meter has recorded the desired quantity of beer. Once the keg is full, the beer will escape via valve 24 and pressure relief valve 26 but when this condition is reached the pressure drop across orifice 51 will be greater than that when gas is flowing there-through and the pressure sensing switch 52. up-stream of the orifice 51, will sense a rise in pressure. This will cause the switch 52 to apply an electrical output to switch 28 by way of line 53, to cut-off the supply of beer to the keg by operation of inlet valve 16. Subsequent operation of the apparatus is as described above once the switch 28 has been opened.

In the modification above described, the orifice 51 and pressure sensing switch 52 have been shown as disposed upstream of the valve 24. However. the orifice and pressure switch may be located down-stream of this valve if desired, or the orifice 51 may be incorporated in such valve with the pressure switch 52 arranged to sense pressure upstream thereof having regard to the direction of flow of gas and/or beer during filling of the keg.

WHAT WE CLAIM IS: 1. A method of racking beer into a keg so that when the keg has been filled with a desired quantity of beer and sealed there will be a predetermined top pressure of gas on the beer, comprising initlally filling the keg with gas to a higher pressure than said predetermined pressure, supplying beer to the keg while allowing said gas to escape from the keg but maintaining the pressure of gas in the keg at a greater value a said predetermined pressure, terminating the supply of beer to the keg when said desired quantity has been delivered, subsequently allowing the pressure in the keg to decrease to said predetermined pressure, and then sealing the keg.

2. Apparatus for racking beer into a keg so that when the keg has been filled with the desired quantity of beer and sealed there will be a predetermined top pressure of gas on the beer, the apparatus comprising means for filling a keg at a pressure higher than said predetermined pressure, means for connecting the keg to a supply of beer and to a gas cxhaust, and inlet means to control entry of beer to the keg, and outlet means to control the escape of gas from the keg as beer is supplied thereto and to control the pressure of the gas in the keg, means for closing the inlet means independently of the outlet means, and means to sense the pressure in the keg and close the outlet means after the inlet means has closed and when said pressure falls to said predetermined pressure.

3. Apparatus according to Claim 2 wherein the outlet means comprises a pressure relief valve to control the gas pressure in the keg during filling and means to allow controlled decay of the pressure in the keg after said inlet means has been closed.

4. Apparatus according to Claim 3 wherein the outlet means comprises a pressure relief valve which can be caused to operate as fixed orifice through which gas and/or beer escapes and which controls the rate at which the pressure in the keg decays after the inlet means is closed.

5. Apparatus according to Claim 4 wherein the pressure relief valve is converted into a fixed orifice device by a signal generated upon closing of the inlet means.

6. Apparatus according to any one of Claims 2 to 5 wherein the connecting means includes a beer meter to meter the supply of beer to the keg and for producing a signal for closing the inlet means when the desired quantity of beer has been delivered to the keg.

7. Apparatus according to Claim 4 wherein the keg is brim filled and there is provided means for closing the inlet means upon a rise of pressure at the outlet means due to the beer reaching a fixed orifice through which the gas has been exhausted, the orifice causing a greater rise in pressure when operating on the liquid beer than when operating on the gas.

8. A method of racking beer into a keg,

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. sed along the line 31, therefore, the piston 45 is lifted which lifts the needle 43 until an abutment 48 on the needle comes into engagement with a face 49 on a housing. The abutment 48 has an orifice 50 which is of known size and communicates with the conduit 25. It is through this orifice 50 that the pressure in the keg escapes when the keg has been filled. The invention includes filling the container in an inverted position in which case the beer will enter the lower end of the keg and the gas will escape through the downtube 18. The invention is also concerned with a pressure relief valve which is convertible to a fixed orifice as described in relation to Figure 2. In a possible modification to the apparatus above described, the beer meter 15 and the line 27 by which its output signal is applied to the switch 28, may be omitted. In this case, a fixed orifice valve 51 would be incorporated in the conduit which connects the fitting 17 of the keg to the valve 24 and pressure relief valve 26, and a pressure sensing switch 52 connected at a position to sense the pressure upstream of the orifice 51. The switch 52 is connected by a line 53 to the switch 28. to operate the switch 28 when the pressure sensed by switch 52 exceeds a predetermined value. In operation of apparatus incorporating, this modification, beer being supplied to the keg by pump 14 will brim fill the keg instead of being cut-off when the meter has recorded the desired quantity of beer. Once the keg is full, the beer will escape via valve 24 and pressure relief valve 26 but when this condition is reached the pressure drop across orifice 51 will be greater than that when gas is flowing there-through and the pressure sensing switch 52. up-stream of the orifice 51, will sense a rise in pressure. This will cause the switch 52 to apply an electrical output to switch 28 by way of line 53, to cut-off the supply of beer to the keg by operation of inlet valve 16. Subsequent operation of the apparatus is as described above once the switch 28 has been opened. In the modification above described, the orifice 51 and pressure sensing switch 52 have been shown as disposed upstream of the valve 24. However. the orifice and pressure switch may be located down-stream of this valve if desired, or the orifice 51 may be incorporated in such valve with the pressure switch 52 arranged to sense pressure upstream thereof having regard to the direction of flow of gas and/or beer during filling of the keg. WHAT WE CLAIM IS:

1. A method of racking beer into a keg so that when the keg has been filled with a desired quantity of beer and sealed there will be a predetermined top pressure of gas on the beer, comprising initlally filling the keg with gas to a higher pressure than said predetermined pressure, supplying beer to the keg while allowing said gas to escape from the keg but maintaining the pressure of gas in the keg at a greater value a said predetermined pressure, terminating the supply of beer to the keg when said desired quantity has been delivered, subsequently allowing the pressure in the keg to decrease to said predetermined pressure, and then sealing the keg.

8. A method of racking beer into a keg,

substantially as hereinbefore described.

9. Apparatus for racking beer into a keg, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.