DESC:Field of the Invention:
The present Invention is in the field of flow control/restrictor unit. The Invention particularly discloses a flow control unit or flow restrictor and its method of manufacturing.

Background of the Invention:
Every reverse osmosis unit has a device called a flow restrictor that determines the amount of water that flows to drain. The flow restrictor or the flow control unit, as the name suggests, restricts the flow of brine (reject water) in drain line leaving the membrane. It provides resistance, creating pressure against the membrane and forcing some of the water, called permeate or product water, through the membrane. Without the resistance provided by the drain line flow restrictor, all the water entering the membrane housing would simply take the path of least resistance and exit through the drain line. Thus, the Flow Restrictor is useful for creating pressure throughout the membrane element and for maintaining the desired ratio of reject flow and permeate flow.

In general, the flow restrictor must be sized to fit the membrane production size. For the high recovery RO system, low flow restrictors are required in the range of <100 ml/min. But such low capillary flow restrictors are not available in the market.

The conventional flow restriction device/s suffers with drawback/s in terms of lacking accuracy with respect to the flow rate. It is also seen that the smaller (in diameter) the tubes become, the more prone they become to particulate clogging. Also, the conventional flow restrictor devices are difficult and expensive to manufacture. The present manufacturing process of the standard flow restrictor design takes long time as it involves the steps of gluing and drying in the oven. The manufacturing of conventional flow restriction devices comprises the steps of Boring of middle plastics part, Assembly of the capillary tube with glue followed by Curing in oven, assembly of the mesh, Joining of the two end parts using glue, Curing for few more days followed by fastening the quick connectors at both the end parts. Such method/s takes more than 7 days in the manufacturing of flow restrictor.

The existing flow restriction unit also suffers with the issue that in case of any clogging/blocking situation, the complete unit needs to be replaced due to lack of provision for replacing the clogged part separately without disturbing the whole unit.

WO2004022136 discloses flow restrictor comprising a flow-restricting channel formed between at least a first member and a second member arranged in contact with each other, the flow channel being arranged to form at least one generally U-formed portion with a pair of opposed first and second channel portions, and with a safety channel arranged between the opposed first and second channel portions

US7431045 discloses a flow restrictor with a first disk having at least one inlet and at least one outlet and a flow path and a second disk having no flow path. The first disk and the second disk are stacked together.

Research is going on to find/explore the flow restrictor unit which could address the above mentioned problems. Particularly, there is needed an efficient flow restrictor unit, which can be assembled with plurality of detachable or attachable connections, so that in case of any clogging/blocking situation, only the clogged part can be replaced without disturbing the whole flow restrictor unit. There is also a need of a flow restrictor unit which can be manufactured through shorter, simple and effective method steps without using glue or any other adhesive for the fitments of the components in the manufacturing of flow restrictor and is still able to withstand the required pressure and flow rates.

Object(s) of the Invention:
A primary object of the present invention is to overcome the drawbacks associated with the
prior art.
Yet another object of the present invention is to provide an efficient flow control/restrictor unit.
Yet another object of the present invention is to provide an efficient flow control/restrictor unit, which can be assembled with plurality of detachable or attachable connections, so that in case of any clogging/blocking situation, only the clogged part can be replaced without disturbing the whole flow restrictor unit.

Yet another object of the present invention is to provide a flow control/restrictor unit comprising snap fitted or press-fitted components/parts.
Yet another object of the present invention is to provide a flow restrictor which can be manufactured through shorter, simpler and effective method steps and is still able to withstand the required pressure and flow rates.
Yet another object of the present invention is to provide a simple and effective method of manufacturing the flow restrictor which replaces the conventional steps of using glue or any other adhesive and drying in oven for fitments of the components.
Yet another object of the present invention is to provide a flow restrictor customized to achieve different flow rates.
Yet another object of the present invention is to provide a shorter, simpler and effective method of manufacturing the flow restrictor.
Yet another object of the present invention is to provide a method of manufacturing the flow restrictor where the fitment of all the individual component are through snap fit or press-fit with O-ring sealing.
Summary of the Invention:
In an aspect of the Invention, there is provided an efficient fluid flow restrictor with assembly/disassembly mechanism for its easy repair/replacement, comprising:
a) at least a quick connector elbow adapted for allowing said fluid to enter in said flow restrictor through an inlet;
b) plurality of stainless steel mesh mounted at the front end of said elbow for filtering said fluid;
c) atleast a plastic part (2), detachably attached at the front end of said quick connector elbow;
d) a hypodermic needle fixed inside a tube, detachably attached with said plastic part (2) from its proximal end;
e) atleast a nozzle shaped plastic part (1), detachably attached with said plastic part (2), where said plastic part (1) is attached with the proximal end of said hypodermic needle, adapted to egress the water through an outlet of said flow restrictor;
f) plurality of O-rings sleeved over said plastic part (2) and said elbow;
g) atleast a bypass mechanism connecting Inlet of said flow restrictor to its outlet.
In another aspect of the Invention, there is provided a method of manufacturing the fluid flow restrictor as described above. The method comprises following steps:
a) assembling said plurality of O-rings to said plastic part (2)
b) assembling said hypodermic needle to said plastic part (2) with said detachable or replaceable connectors comprising quick fit or press fit or snap fit or threaded joint or similar other detachable locking connections
c) sliding said hypodermic needle into said plastic part (1) followed by snapping it to said plastic part (2)
d) fastening atleast 1/4th of said quick connector elbow with the assembly resulting from step (c) to obtain said fluid flow restrictor

Brief Description of the Drawings:

To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings in which:

Figure 1: illustrates a) overview of the flow restrictor b) sectional view of the flow restrictor c) direction of water flow through the flow restrictor
Figure 2: illustrates method steps involved in manufacturing the flow restrictor
Figure 3: (a) and (b) illustrates an embodiment of method steps involved in manufacturing the flow restrictor
Figure 4: (a) and (b) illustrates another embodiment of method steps involved in manufacturing the flow restrictor (c) method steps involved in manufacturing the flow restrictor with spring loaded plunger
Figure 5: illustrates the efficiency of the flow restrictor in terms of flow variation and recovery impact

Detailed Description of the Invention:

For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof. Throughout the patent specification, a convention employed is that in the appended drawings, like numerals denote like components.

Reference throughout this specification to “an embodiment”, “another embodiment”, “an implementation”, “another implementation” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrase “in an embodiment”, “in another embodiment”, “in one implementation”, “in another implementation”, and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such method. Similarly, one or more devices or sub-systems or elements or structures proceeded by "comprises... a" does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or additional devices or additional sub-systems or additional elements or additional structures of the flow restrictor as described below.

The present Invention provides a Flow control unit or a Flow restrictor unit and its method of manufacturing. The Flow control unit or a Flow restrictor unit is useful for restricting fluids and gases.

The flow restrictor as provided by the present Invention can be manufactured through shorter, simple and effective method steps and is still able to withstand the required pressure and flow rates.

In an embodiment, the Flow restrictor comprises following essential components:
1) Plurality of Plastic Parts, particularly Plastic Part 1 and Plastic Part 2
2) Plurality of O-Rings
3) Hollow needle
4) Quick connector
5) Spring loaded plunger
In an embodiment, all the components/parts of the flow restrictor are fitted through snap fit or press-fit or slide fit mechanism with O-ring sealing.
In another embodiment, the flow restrictor comprises detachable components/parts with snap-fitted mechanism, which allows easy replacement of any component as needed. The arrangement facilitates the customization of the flow restrictor as needed.
In an embodiment, the needle is a hypodermic needle.
In an embodiment, the needle is detachable and replaceable.
In another embodiment, the needle is attached through press fitting arrangement.
In another embodiment, the Quick connector is threaded.
In another embodiment, the Quick connector is snap/press fitted.
In an embodiment, if the pressure into the flow restrictor increases more than the limit (either due to downstream pressure increase or due to chocking of the FR), the spring loaded plunger opens and water is channelized to flow through by-pass across the needle. This protects the RO membrane from seeing very high back pressure and ultimate issues with seal integrity.
Yet another object of the present invention is to provide a flow restrictor customized to achieve different flow rates. In such embodiment, the needle with varying diameter can be used for achieving the desired flow rate.
In a preferred embodiment, there is provided an efficient fluid flow restrictor with assembly/disassembly mechanism for its easy repair/replacement. The flow restrictor comprises:
a) at least a quick connector elbow adapted for allowing said fluid to enter in said flow restrictor through an inlet;
b) plurality of stainless steel mesh mounted at the front end of said elbow for filtering said fluid;
c) atleast a plastic part (2), detachably attached at the front end of said quick connector elbow;
d) a hypodermic needle fixed inside a tube, detachably attached with said plastic part (2) from its proximal end;
e) atleast a nozzle shaped plastic part (1), detachably attached with said plastic part (2), where said plastic part (1) is attached with the proximal end of said hypodermic needle, adapted to egress the water through an outlet of said flow restrictor;
f) plurality of O-rings sleeved over said plastic part (2) and said elbow;
g) atleast a bypass mechanism connecting Inlet of said flow restrictor to its outlet.
In an embodiment, the bypass mechanism is adapted to control and bypass the overflow of said fluid from entering in said flow restrictor in a clog situation.
In an embodiment, the tube is made of material comprising steel, Poly Vinyl Chloride (PVC), Polyethylene terephthalate (PET), copper and like material.
In an embodiment, the tube is a Poly-ethylene tube.
In another embodiment, the bypass mechanism comprises atleast a spring loaded plunger.
In an embodiment, the plunger is a combination of plastic and rubber based material.
In an embodiment, the plunger comprises plastic and rubber based material as separate parts.
In an embodiment, the plunger comprises the combination of plastic and rubber based material as one single components/part over the molded component.
In an embodiment, the plunger comprises atleast a spring with a screw. The screw facilitates adjusting the tension of plunger.
In another embodiment, the plurality of O-rings are adapted to provide tight sealing for preventing the back flow/leakage of said fluid.
The assembly/disassembly mechanism comprises detachable or replaceable connections mechanized with locking connections comprising press fit or snap fit or threaded joint or similar other detachable locking connections, adapted to hold parts of said flow restrictor.
In an embodiment, the distal end of said Hypodermic needle is the open end. The distal end of said Hypodermic needle is housed inside said polyethylene tube and is in the direction of the flow.
In an embodiment, the plastic part (2) comprises configuration of step-wise decreasing internal aperture, tailored for increasing the pressure and subsequently restricting the rate of flow said fluid.
In an embodiment, the sequential connection of said elbow, said plastic part (2) and said hypodermic needle is in decreasing order of their respective internal orifice.

Construction of the flow Restrictor:
In an embodiment, the construction of Flow Restrictor (FR) is shown in Figure 1. As shown in figure 1, the FR is connected to the Reject (or concentrated) line of the RO membrane through Plastic Part 1 (Figure 1b).
In an embodiment, the flow restrictor comprises small diameter due to which it provides resistance and thus creating pressure against the membrane and forcing some of the water, called permeate or product water, through the membrane. The radius of inner side of FR is done in sequential way so as to reduce the hammering effect inside the FR.
The Concentrated or RO’s reject water enters the FR through the quick connector elbow (threaded or snap/press fitted) which is connected on the reject line and flows through and passes to the Plastic part 2 (figure 1b). The plastic part 2 has threaded seal over the circumference part that is connected to quick connector and on the other side it has provision for sealing with the Plastic Part 1. The hypodermic needle is attached at the other end of the Plastic Part 2 by simple press fit mechanism.
The Plastic part 1 is then put over the Plastic Part 2 & Needle assembly and the fitment between the plastic part 1and 2 is through a locking mechanism. There are locks provided on Plastic Part 2 and other on guiding ribs, which locks the two parts with each other. The water that enters the Plastic Part 2 is prevented from back flowing due to plurality of O-ring sealing and thereafter it flows forward to the hollow opening to the needle and then out of the flow restrictor.
The FR assembly has been pressure tested and it can withstand up to 400 psi of pressure without leakage.
In an embodiment, various opening of the hypodermic needle can be incorporated in the present flow restrictor. The needle can be detachable and replaceable.
In another aspect of the Invention, there is provided a method of manufacturing the flow restrictor.
In a preferred embodiment, the method of manufacturing the fluid flow restrictor comprises following steps:
a) assembling said plurality of O-rings to said plastic part (2)
b) assembling said hypodermic needle to said plastic part (2) with said detachable or replaceable connectors comprising quick fit or press fit or snap fit or threaded joint or similar other detachable locking connections
c) sliding said hypodermic needle into said plastic part (1) followed by snapping it to said plastic part (2)
d) fastening atleast 1/4th of said quick connector elbow with the assembly resulting from step (c) to obtain the fluid flow restrictor
The pointed end of said needle is potted with an adhesive to reduce its movement/bending
The method is highly efficient, shorter and simple, which substantially reduces the time period of manufacturing the flow restrictor as compared to regular/traditional flow restrictors.
The method advantageously eliminates the steps of employing glue and drying in oven for the fitments of the components in the manufacturing method of the flow restrictor.
The manufacturing time of flow restrictors has significantly reduced without compromising/ loosing the functionality of any part/components of the flow restrictor. The flow restrictor is also able to withstand the required pressure and flow rates.

In an embodiment, all the components/parts of the flow restrictor are fitted through snap fit or press-fit or slide fit mechanism with O-ring sealing. The basic step of manufacturing the flow restrictor is elaborated in Figure 2.

In an embodiment, the method of manufacturing flow restrictor comprises following essential steps. The following steps are various ways that the Flow Restrictor of the present Invention can be made.
a) Step 1: The hypodermic needle can be inserted inside a polyethylene tube and the whole assembly is further inserted inside a higher diameter tube. To lock the movement of the capillary, quick-fit end connectors are added at both the ends. The arrangement is illustrated in figure 3(a).
b) Step 2: The hypodermic needle can be inserted inside a PE tube and the pointed end of the needle assembly is potted with glue to reduce movement/bending of the capillary. In an embodiment, the needle is detachable and replaceable. The arrangement is illustrated in figure 3(b).
c) Step 3: Using snap-fit and press fit for assembling the FR but using non-threaded quick connector instead of threaded quick connector. The arrangement is illustrated in figure 4(a).
d) Step 4: Putting a threaded quick connector at end of the outset of the FR. The arrangement is illustrated in figure 4(b).

In an embodiment, if the pressure into the FR increases more than the limit (either due to downstream pressure increase or due to chocking of the FR), the spring loaded plunger opens and water is by-pass across the needle. This protects the RO membrane from seeing very high back pressure and ultimate issues with seal integrity. The arrangement is illustrated in figure 4(c).
The flow restrictor has wide applications in Residential RO Systems and in any system requiring low flow restrictor.
The efficiency of the flow restrictor can be seen through following experimental results. The results are also illustrated in Figure 5.The data shows that the flow rates and Recovery rate is appropriate.
Flow Variation:

Restrictor # 30 PSI Flow (mL/min) 60 PSI Flow (mL/min) 90 PSI Flow (mL/min)
16 92 126 150
17 90 130 150
2 90 124 152
13 88 124 152
5 90 130 154
7 88 126 154
30 90 128 154
1 96 134 158
4 92 128 158
21 92 130 158
27 92 128 158
32 94 130 158
8 92 132 160
11 98 134 160
12 94 130 160
19 96 134 160
23 92 132 160
24 92 130 160
26 94 134 160
28 94 128 160
20 96 136 162
14 98 136 164
15 94 134 164
18 94 134 164
25 94 134 164
22 96 132 166
31 98 136 166
9 94 134 168
6 98 140 170
29 100 138 170
3 94 130 174
10 100 146 174
Average 93.8 131.9 160.7
Minimum 88 124 150
Maximum 100 146 174
Std Dev 3.2 4.6 6.3

Recovery Impact:

Assumed Permeate Flow mL/min 66 131 197
Restrictor # 30 PSI Recovery 60 PSI Recovery 90 PSI Recovery
16 42% 51% 57%
17 42% 50% 57%
2 42% 51% 56%
13 43% 51% 56%
5 42% 50% 56%
7 43% 51% 56%
30 42% 51% 56%
1 41% 49% 55%
4 42% 51% 55%
21 42% 50% 55%
27 42% 51% 55%
32 41% 50% 55%
8 42% 50% 55%
11 40% 49% 55%
12 41% 50% 55%
19 41% 49% 55%
23 42% 50% 55%
24 42% 50% 55%
26 41% 49% 55%
28 41% 51% 55%
20 41% 49% 55%
14 40% 49% 55%
15 41% 49% 55%
18 41% 49% 55%
25 41% 49% 55%
22 41% 50% 54%
31 40% 49% 54%
9 41% 49% 54%
6 40% 48% 54%
29 40% 49% 54%
3 41% 50% 53%
10 40% 47% 53%
Average 41.31% 49.84% 55.09%
Minimum 39.76% 47.29% 53.10%
Maximum 42.86% 51.37% 56.77%
Std Dev 0.822% 0.870% 0.968%

,CLAIMS:WE CLAIM:

1) An efficient fluid flow restrictor with assembly/disassembly mechanism for its easy repair/replacement, comprising:

a) at least a quick connector elbow adapted for allowing said fluid to enter in said flow restrictor through an inlet;
b) plurality of stainless steel mesh mounted at the front end of said elbow for filtering said fluid;
c) atleast a plastic part (2), detachably attached at the front end of said quick connector elbow;
d) a hypodermic needle fixed inside a tube, detachably attached with said plastic part (2) from its proximal end;
e) atleast a nozzle shaped plastic part (1), detachably attached with said plastic part (2), where said plastic part (1) is attached with the proximal end of said hypodermic needle, adapted to egress the water through an outlet of said flow restrictor;
f) plurality of O-rings sleeved over said plastic part (2) and said elbow;
g) atleast a bypass mechanism connecting Inlet of said flow restrictor to its outlet.
2) The flow restrictor as claimed in claim 1, wherein said bypass mechanism is adapted to control and bypass the overflow of said fluid from entering in said flow restrictor in a clog situation.
3) The flow restrictor as claimed in claim 1, wherein said tube is made of material comprising Polyethylene terephthalate, Steel, Poly Vinyl Chloride, Copper and like material.
4) The flow restrictor as claimed in claim 1, wherein said bypass mechanism comprises atleast a spring loaded plunger.
5) The flow restrictor as claimed in claim 1, wherein said plurality of O-rings are adapted to provide tight sealing for preventing the back flow/leakage of said fluid.
6) The flow restrictor as claimed in claim 1, wherein said assembly/disassembly mechanism comprises detachable or replaceable connections mechanized with locking connections comprising quick fit or press fit or snap fit or threaded joint or similar other detachable locking connections, adapted to hold parts of said flow restrictor.
7) The flow restrictor as claimed in claim 1, wherein the distal end of said Hypodermic needle is the open end.
8) The flow restrictor as claimed in claim 1, wherein the distal end of said Hypodermic needle is housed inside said polyethylene tube and is in the direction of the flow.
9) The flow restrictor as claimed in claim 1, wherein said plastic part (2) comprises configuration of step-wise decreasing internal aperture, tailored for increasing the pressure and subsequently restricting the rate of flow said fluid.
10) The flow restriction device as claimed in claim 1, wherein sequential connection of said elbow, said plastic part (2) and said hypodermic needle is in decreasing order of their respective internal orifice.
11) The flow restriction device as claimed in claim 1, wherein said needle is detachable and replaceable.
12) A method of manufacturing the fluid flow restrictor as claimed in claim 1, wherein said method comprises the steps of:
a) assembling said plurality of O-rings to said plastic part (2)
b) assembling said hypodermic needle to said plastic part (2) with said detachable or replaceable connectors comprising quick fit or press fit or snap fit or threaded joint or similar other detachable locking connections
c) sliding said hypodermic needle into said plastic part (1) followed by snapping it to said plastic part (2)
d) fastening atleast 1/4th of said quick connector elbow with the assembly resulting from step (c) to obtain said fluid flow restrictor
13) The method as claimed in claim 12, wherein said the pointed end of said needle is potted with an adhesive to reduce its movement/bending.