EP0593125A1

EP0593125A1 - Fluid flow divider

Info

Publication number: EP0593125A1
Application number: EP93202868A
Authority: EP
Inventors: Jeffery Michael c/o KODAK LIMITED Owen; Derek c/o KODAK LIMITED Law
Original assignee: Kodak Ltd; Eastman Kodak Co
Current assignee: Kodak Ltd; Eastman Kodak Co
Priority date: 1992-10-15
Filing date: 1993-10-12
Publication date: 1994-04-20
Also published as: JPH06239400A; GB9221624D0

Abstract

An apparatus for the division of a fluid flow from a source into a plurality of streams, in which each arm contains a set of two-gear meshing gears coupled with a common shaft which can be rotated by turbine action by fluid passing along the arm and through gaps in the meshing gears, or the conduit contains a three- or more- gear set of meshing gears coupled with a common shaft which can be rotated by turbine action by fluid flowing through gaps in the gears.

Description

This invention relates to a fluid flow dividing method and apparatus and in particular to a precision fluid flow divider which enables fluid delivery from a single source to be divided precisely by a fixed ratio to two or more lines.
In a number of manufacturing processes the need arises to have separate measurement and control of these identical fluid streams. Conventionally, separate flow-lines, pumps and flow meters are used to supply the identical fluids in a precision manner in these situations.
The need to supply two or more identical fluids to the same process step arises in the photographic industry. During coating of photographic film or paper it is frequently necessary to put on two or more identical coating layers which means supplying two or more identical coating solutions to the same coating step. At present the identical coating solutions are supplied in a conventional way using two or more completely seperate supply systems.
Thus in the coating of photographic films and papers parts of the solution delivery system comprising expensive items of equipment such as pumps and flow meters are effectively doubled up. This not only materially adds to the costs of the coating process but the additional supply equipment increases the amount of space required by the coating operation.
An efficient system of dividing fluid flow from a source and delivering the divided flows to a process step in a precise manner would offer considerable advantages in terms of economies in cost and space to a number of industries including the photographic industry.
According to the present invention we provide a method for the division of a fluid flow from a source into a plurality of streams in which the fluid either (a) is caused to enter a conduit set across its line of flow and to flow in different directions along the arms of the conduit on either side of its point of entry, or (b) flows along a conduit; characterised in that the fluid either (a) flows along the arms to two-gear sets of meshing gears located in both arms and coupled with a common shaft and the fluid flow in each arm rotates the meshing gears therein by turbine action with fluid passing through gaps in the gears, or (b) flows along the conduit through a three- or more- gear set of meshing gears coupled with a common shaft and the fluid flow rotates the meshing gears by turbine action with fluid flowing through gaps in the gears.
Further according to the present invention we provide a process for supplying a fluid from a single source via a plurality of streams to a system in which the fluid either (a) is caused to enter a conduit set across its line of flow and to flow in different directions along the arms of the conduit on either side of its point of entry, the streams flowing seperately to the system, or (b) flows along a conduit to the system; characterised in that the fluid either (a) flows along the arms to two-gear sets of meshing gears located in both arms and coupled with a common shaft and the fluid flow in each arm rotates the meshing gears therein by turbine action with fluid passing through gaps in the gears, or (b) flows along the conduit through a three- or more- gear set of meshing gears coupled with a common shaft and the fluid flow rotates the meshing gears by turbine action with fluid flowing through gaps in the gears.
Further according to the present invention we provide an apparatus for the division of a fluid flow from a source into a plurality of streams which comprises a conduit and connecting means communicating with the interior thereof to enable fluid to flow from the source and enter the conduit, and in which the conduit either (a) may or (b) may not have an arm on each side of the fluid entry point so that fluid is able to flow in different directions along the arms of the conduit characterised in that either (a) each arm contains a set of two-gear meshing gears coupled with a common shaft which can be rotated by turbine action by fluid passing along the arm and through gaps in the meshing gears or (b) the conduit contains a three- or more- gear set of meshing gears coupled with a common shaft which can be rotated by turbine action by fluid flowing through gaps in the gears.
The process of the invention may be used in any situation in which it is necessary to supply two or more separate but identical fluid streams to the same step or system in another process.It may be used with great advantage in the photographic industry where, as stated above, the need to supply two or more identical fluids to the same process step arises. The process of the invention can thus be used as a step in the coating of photographic film or paper when it is necessary to put on two or more identical coating layers and two or more identical coating solutions must be supplied to the same coating step. The process of the invention can also be used elsewhere e. g. in the manufacture of plastic bottles. The method of the invention is useful in a wide range of situations in which it is necessary to divide fluid flows.
The invention is applicable to liquids and gases and in particular to solutions such as those used in coating photographic films and papers. It is very suitable for dividing the flow of viscous liquids for instance liquids having viscosities in the range 10 to 1000 centipoise.
In its simplest embodiment the apparatus of the invention employs a device such as a "Y" piece or a "T" piece to divide the flow of fluid to two sets of meshing gears which are coupled with a common shaft. The flow down one arm of the "Y" turns one set of the meshing gears by turbine action, this in turn rotates the other set of gears which then meters the flow down the other arm of the "Y". The two sets of gears will turn at the same speed since they are coupled with a common shaft. If the two sets of gears are identical in their volume per revolution displacement then the flows down each arm will be identical. Different flow ratios can be achieved by different sets of gears sizes or by coupling the gears by a variable ratio gearbox. Alternatively the lengths of the gear plates can differ between the two sets with the relative proportions of fluid passing through each depending upon the relative lengths. When the apparatus is in operation, fluids, particularly liquids, are swept around by the moving teeth of the meshing gears and the amount of fluid passing through the gears depends upon the amount trapped by the teeth.
In the simple embodiment of the apparatus which is described above each set of gears comprises two meshing gears. However in more developed embodiments the sets could comprise greater numbers of meshing gears for example three, four or more. With more than two gears per set of gears it is possible to divide the flow of fluid after it passes through this gear set. Thus with a three gear set the fluid flow can be divided into two parts on passing through the gear set.
In the simplest apparatus of the invention the sets of gears and other body parts, such as entry and exit ports are generally positioned in line along the conduit and are held together by suitable means e. g. by rods or bolts.
The invention eliminates the need seperately to measure and control identical fluid flows (e.g. of solutions) to a manufacturing process such as a process for coating photographic film or paper. Instead of using separate supply systems for different flows, in the case where the flows are identical and their ratios are fixed, the invention can reduce the number of separate control systems required to one. Using the invention, solution delivery in a precise manner from a single control system can be divided precisely by a fixed ratio to two or more lines.
The invention enables savings in expense and space to be achieved and, when installed in an existing system already with two supply lines, it allows an existing line to be retained as spare capacity for use in the event of a partial shut-down.
The invention is illustrated by the accompanying drawings wherein:

Figure 1 is an exploded view of a simple embodiment of the apparatus of the invention having two-gear sets of meshing gears ((a) above);
Figure 1a is an operational diagram of the apparatus of Figure 1; and
Figure 2 is a exploded view of an alternative embodiment of the apparatus of the invention having a three-gear set of meshing gears ((b) above).

In the apparatus of Figure 1 two identical sets of meshing gears 1 and 2, from identical proprietory small gear pumps but separated from the drive motors thereof, are coupled with a common shaft 3. Two-gear sets 1 and 2 are located on conduit 4 with between them, also on conduit 4, entry port 5 which is connected to pipe 6. Exit ports 7 and 8 are also located on conduit 4 on the sides of gear sets 1 and 2 away from entry port 5. The system has effectively five pieces or body parts positioned along a common centre line.
In operation fluid from a source (not shown in the drawing) passes along pipe 6, through entry port 5 and into conduit 4. In conduit 4 the fluid flows in opposite directions along the arms of the conduit containing gear sets 1 and 2, turning the gears by turbine action. In effect fluid passes through entry port 5 and is driven by pressure through gear sets 1 and 2 which are forced round at the same speed.The fluid passes through gaps 9 and 10 between the teeth of the gears and then flows on to exit ports 7 and 8.
An apparatus as described above has been installed into a conventional solution delivery system for a photographic film coating process in which solution is supplied from a separate metering pump. Solution flow rates from each of the outlets of the device were measured using magnetic flow meters.
This arrangement functioned satisfactorily; dividing the flows equally even with large differential back pressures on each outlet. Flows up to 1.5 litres/ minute from each outlet could be achieved to within 3% accuracy and a differential pressure of 5 psi using 150 centipoise viscosity solution.
Figure 2 shows a larger apparatus of the invention. This has a conduit 11 with an entry port 12 through which fluid is supplied from a source (not shown in the drawing). Also located in the conduit is a three-gear meshing gear set 13 coupled with a common shaft 14. Fluid is forced through gear set 13 under pressure and its flow is divided into two paths 15 and 16 as the fluid passes through gaps 17 in the teeth.
The apparatus of Figure 2 can be used in a process for coating photographic film or paper using for example interlayer solutions with viscosities around 150 centipoise and flows up to 2 litres/minute.

Claims

A method for the division of a fluid flow from a source into a plurality of streams in which the fluid either (a) is caused to enter a conduit set across its line of flow and to flow in different directions along the arms of the conduit on either side of its point of entry, or (b) flows along a conduit; characterised in that the fluid either (a) flows along the arms to two-gear sets of meshing gears located in both arms and coupled with a common shaft and the fluid flow in each arm rotates the meshing gears therein by turbine action with fluid passing through gaps in the gears, or (b) flows along the conduit through a three- or more- gear set of meshing gears coupled with a common shaft and the fluid flow rotates the meshing gears by turbine action with fluid flowing through gaps in the gears.
A method according to claim 1 characterised in that the fluid is a liquid.
A method according to claim 2 characterised in that the liquid has a viscosity in the range 10 to 1000 centipoise.
A process for supplying a fluid from a single source via a plurality of streams to a system in which the fluid either (a) is caused to enter a conduit set across its line of flow and to flow in different directions along the arms of the conduit on either side of its point of entry, the streams flowing seperately to the system, or (b) flows along a conduit to the system; characterised in that the fluid either (a) flows along the arms to two-gear sets of meshing gears located in both arms and coupled with a common shaft and the fluid flow in each arm rotates the meshing gears therein by turbine action with fluid passing through gaps in the gears, or (b) flows along the conduit through a three- or more- gear set of meshing gears coupled with a common shaft and the fluid flow rotates the meshing gears by turbine action with fluid flowing through gaps in the gears.
A process according to claim 4 characterised in that the system is a system for coating photographic film or paper.
An apparatus for the division of a fluid flow from a source into a plurality of streams which comprises a conduit and connecting means communicating with the interior thereof to enable fluid to flow from the source and enter the conduit, and in which the conduit either (a) may or (b) may not have an arm on each side of the fluid entry point so that fluid is able to flow in different directions along the arms of the conduit characterised in that either (a) each arm contains a set of two-gear meshing gears coupled with a common shaft which can be rotated by turbine action by fluid passing along the arm and through gaps in the meshing gears or (b) the conduit contains a three- or more- gear set of meshing gears coupled with a common shaft which can be rotated by turbine action by fluid flowing through gaps in the gears.