WO2008080355A1

WO2008080355A1 - Fluid distribution device and method for manufacturing the same

Info

Publication number: WO2008080355A1
Application number: PCT/CN2007/071378
Authority: WO
Inventors: Wenhui Wang; Youqi Wang; Yonghua Xu; Yirong Yang; Ling Liu; Youshu Kang; Guangping Xie; Xianzhong Zhao; Wenhu Shen; Bin Chen
Original assignee: Accelergy Shanghai R & D Center Co Ltd; Accelergy Corp
Current assignee: Accelergy Shanghai R & D Center Co Ltd; Accelergy Corp
Priority date: 2006-12-28
Filing date: 2007-12-28
Publication date: 2008-07-10
Anticipated expiration: 2009-06-28
Also published as: CN101311614A

Abstract

A fluid distribution device (1; 2; 3; 6; 7; 8; 9; 11; 12) includes a core (102; 202; 401; 601; 701; 801; 901), a shell (101; 201; 301; 602; 702; 802; 902), at least one common port (107; 207; 302, 303; 705; 805; 905; 114,115; 124,125), multiple branch ports (105; 205; 304; 706; 806; 906; 116; 126), and distributing channels (108; 209; 403; 604; 707; 807; 907; 117; 127) fluidly connecting the common port with the multiple branch ports, respectively. The core has a substantially circumferential outer surface (106; 206; 402; 603; 703; 803; 903) and the shell has a substantially circumferential inner surface (104; 204; 501; 605; 704; 804; 904) engaging the outer surface of the core. The distributing channels are formed between the outer surface of the core and the inner surface of the shell. The fluid distribution device is capable of uniformly distributing high pressure fluid to multiple parallel reactors.

Description

Fluid distribution device and method for manufacturing the same

FIELD OF INVENTION

[0001] The present invention relates to a fluid distribution device and a

method for manufacturing a fluid distribution device.

BACKGROUND OF THE INVENTION

[0002] Fluid distribution devices are widely used to distribute fluid to

multiple flow paths or channels, or to gather fluids from flow paths or channels.

[0003] In a parallel reaction system for simultaneously evaluating different

materials such as catalysts under substantially same conditions, a fluid

distribution device may be needed to uniformly distribute a reactant to multiple

parallel reactors, i.e., to make reactant flows respectively flowing though the

multiple parallel reactors have substantially same flow rates. In many cases, the

reactant may be a high pressure fluid. Therefore, a fluid distribution device

capable of uniformly distributing high pressure fluid to multiple parallel

reactors may be needed.

SUMMARY OF THE INVENTION

[0004] Embodiments of the present invention provide a fluid distribution

device including a core, a shell, a common port, and multiple branch ports. The

core has a substantially circumferential outer surface and the shell has a substantially circumferential inner surface engaging the outer surface of the core.

Distributing channels are formed between the outer surface of the core and the inner surface of the shell. The distributing channels establish fluid connections between the common port and respective ones of the multiple branch ports. [0005] In one embodiment, the distributing channels are micro-sized and have substantially same flow resistances.

[0006] Embodiments of the present invention further provide a fluid distribution device including a core, a shell, a common port, multiple branch ports, and micro-sized distributing channels fluidly connecting the common port with the multiple branch ports respectively. The core has a substantially circumferential outer surface and a substantially circumferential inner surface, and the shell has a substantially circumferential inner surface tightly engaging the outer surface of the core. The micro-sized distributing channels each has an opening on the inner surface of the core and an opening on the outer surface of the core and extends through the core. Fluid through the micro-sized distributing channels is kept from leaking between the outer surface of the core and the inner surface of the shell by tight engagement between the outer surface of the core and the inner surface of the shell.

[0007] Embodiments of the present invention further provide a method for manufacturing a fluid distribution device including a core and a shell respectively having a substantially circumferential outer surface and a substantially circumferential inner surface. The method includes the following steps: fabricating a common port, multiple branch ports, and micro-sized channels on the core or the shell; assembling the core and the shell in a manner that the outer surface of the core engages the inner surface of the shell and the micro-sized channels fluidly connect the common port with the multiple branch ports respectively; feeding a fluid into the micro-sized channels and measuring flow rates in the micro-sized channels; eroding the micro-sized channels having relatively smaller flow rates by corrosive fluid; and repeating the previous two steps until a flow rate difference of the micro-sized channels is below a predetermined value.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a diagram illustrating a fluid distribution device.

[0009] FIG. 2 is a diagram illustrating another fluid distribution device.

[0010] FIG. 3 is a diagram illustrating yet another fluid distribution device.

[0011] FIG.4 is a diagram illustrating a core of the fluid distribution device of FIG3.

[0012] FIG. 5 is a diagram illustrating a longitudinal cross-sectional view of the fluid distribution device of FIG.3.

[0013] FIG. 6 is a diagram illustrating yet another fluid distribution device.

[0014] FIG. 7 is a diagram illustrating yet another fluid distribution device.

[0015] FIG. 8 is a diagram illustrating yet another fluid distribution device.

[0016] FIG. 9 is a diagram illustrating yet another fluid distribution device. [0017] FIG. 10 is a diagram illustrating yet another fluid distribution device.

[0018] FIG. 11 is a diagram illustrating yet another fluid distribution device.

[0019] FIG. 12 is a diagram illustrating yet another fluid distribution device.

[0020] FIG. 13 is a diagram illustrating yet another fluid distribution device.

[0021] FIG. 14 is a diagram illustrating an embodiment of a sealing element

for a fluid distribution device.

[0022] FIG. 15 is a force diagram of a fluid distribution device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] FIG. 1 illustrates a fluid distribution device 1 including a shell 101

and a core 102. In one embodiment, the shell 101 has a general shape of axially

extending cylinder and is formed with an opening 103 in an axial end thereof

and multiple ports 105 fluidly communicating with the opening 104 in a

cylinder sidewall thereof. The opening 103 defines a circumferential inner

surface 104. The core 102 is a cylinder having a circumferential outer surface

106 and an axial end surface 107. Multiple grooves 108 are formed on the outer

surface 106 and axially extend to the end surface 107.

[0024] The shell 101 and the core 102 can be assembled together with

interference fit, by forcing the core 102 into the opening 103. After the core 102

is received in the opening 103, a residual space of the opening 103 (a space

between the end surface 107 of the core 102 and an end surface of the shell 101,

from which surface the opening 103 is defined) functions as a common port. The grooves 108 are formed into channels (distributing channels) fluidly connecting the common port 103 and the ports 105 respectively. In one embodiment, the distributing channels are substantially the same both in shape and size and therefore have substantially the same flow resistances. The fluid distribution device 1 is capable of distributing a fluid from the common port 103 to the ports (branch ports) 105, or collecting fluids from the branch ports 105 to the common port 103.

[0025] FIG. 2 illustrates a fluid distribution device 2 similar to the fluid distribution device 1, but with two common ports. The fluid distribution device 2 includes a shell 201 and a core 202. In one embodiment, the shell 201 is a hollow cylinder provided therein with a through hole 203 defining a circumferential inner surface 204. The shell 201 further provides multiple ports 205 in a cylinder sidewall thereof to fluidly communicate with the through hole 203. The core 202 is a cylinder having a circumferential outer surface 206 and two axial end surfaces 207 and 208. Multiple grooves 209 are provided on the outer surface 206 of the core 202. In one embodiment, the grooves axially extend and have a length the same as an axial length of the core 202 between the two end surfaces 207 and 208.

[0026] After the core 202 is received in the through hole 203 of the shell 201, there are residual spaces respectively adjacent to two axial ends of the shell 201 in the through hole 203 (one of the axial ends is not shown) and these residual spaces function as two common ports respectively. Each of the grooves 209 is formed into two distributing channels, respectively connecting one of the common ports with a said port 205. In one embodiment, the distributing channels for fluidly connecting the multiple ports 205 with a same common port are substantially the same both in shape and size and therefore have substantially the same flow resistances. The fluid distribution device 2 is capable of distributing fluids from the two common ports to the multiple ports 105, or collecting fluids from the multiple ports 105 to the two common ports. [0027] FIGs. 3-5 illustrate a fluid distribution device 3. Referring to FIG. 3, the fluid distribution device 3 includes a shell 301, two main conduits 302 and 303 and multiple branch conduits 304. In one embodiment, The two main conduits 302 and 303 function as input conduits, and the multiple branch conduits 304 are arranged in a circle in a circumferential direction of the shell 301 and function as output conduits.

[0028] Referring to FIG. 4, the fluid distribution device 3 further includes a core 401. In one embodiment, the core 401 is shaped as a truncated cone or as a slightly tapered cylinder with a circumferential outer surface 402. The outer surface 402 is provided with multiple axially extending grooves 403 and two circumferential grooves 404 and 405 respectively communicating with the grooves 403 from two ends of the grooves 403.

[0029] Referring to FIG. 5, the shell 301 defines a circumferential inner surface 501 closely matching the outer surface 402 of the core 401. In assembly, the core 401 is retained in the shell 301 by retainers, end covers 503 and 504 here, which threadingly engages the shell 301. The main conduits 302 and 303 are respectively connected to the circumferential grooves 404 and 405, which function as first and second common ports. The branch conduits 304 are respectively connected to the grooves 403 at positions between the two circumferential grooves 404 and 405, such that each groove 403 is formed into a first distributing channel 403a fluidly connecting one of the branch conduits 304 with the main conduit 302 and a second distributing channel 403b fluidly connecting the same one of the branch conduits 304 with the main conduit 303. The first distributing channels 403a are substantially the same in shape and size and the second distributing channels 403b are substantially the same in shape and size. The fluid distribution device 3 is capable of distributing fluids from the main conduits 302 and 303 to the multiple branch conduits 304, or collecting fluids from the multiple branch conduits 304 to the main conduits 302 and 303.

[0030] FIG. 6 illustrates a fluid distribution device 6 including a core 601 and a shell 602. The core 601 is a cylinder having a circumferential outer surface 603 provided with multiple grooves 604. The shell 602 includes two sheets covering on the outer surface 603 of the core 601 and defining a discontinuous circumferential inner surface 605. The sheets may be made from deformable materials such as metals or alloys. There is a retainer 607 for retaining the shell 602 on the outer surface 603 of the core 601. In one embodiment, the retainer 607 is a clamp. The fluid distribution device 6 may further include one or more common ports and multiple branch ports, and these ports may be configured as described before or hereafter.

[0031] FIG. 7 illustrates a disassembled state of a fluid distribution device 7. The fluid distribution device 7 includes a core 701 and a shell 702 formed of a sheet-like material, which is shown as a sheet before forming the shell in FIG. 7. The core 701 has a circumferential outer surface 703. In assembly, the sheet-like material is curled to form the shell 702 and a surface 704 of the sheet-like material forms into a circumferential inner surface of the shell 702, which closely covers the circumferential outer surface 703 of the core 701. There are a common port 705 and multiple branch ports 706. The inner surface 704 of the shell 702 is provided with multiple grooves 707, which in assembly are formed into distributing channels fluidly connecting the common port and the multiple branch ports 706 respectively. There are two branch ports 706 shown, the common port 705 comprises two ports 705a and 705b corresponding to the two branch ports 706 respectively and a connecting structure 705c linking the ports 705a and 705b. The distributing channels formed from grooves 707 connect the ports 705a and 705b with their respective branch ports 706. There may be a retainer or the like to retain the shell 702 on the outer surface 703 of the core 701.

[0032] FIG. 8 illustrates a fluid distribution device 8 similar to the fluid distribution device 7, including a core 801 and a shell 802 formed of a sheet-like material. However, in the fluid distribution device 8, grooves 807 are formed on a circumferential outer surface 803 of the core 801 and respectively connect multiple branch ports 806 with a common port 805.

[0033] FIG. 9 illustrates a fluid distribution device 9 including a core 901 and a shell 902. In order to make the core 901 inside the shell 902 be visible, the shell 902 is illustrated as being transparent. The core 901 is a cylinder providing a circumferential outer surface 903. The shell 902 defines a circumferential inner surface 904 closely matching the outer surface 903 of the core 901. There are two common ports 905 (only the upper side one can be seen from FIG. 9 and the lower side one is symmetric to the upper side one), multiple branch ports 906, and multiple distributing channels 907 formed between the engaged outer surface 903 of the core 901 and inner surface 904 of the shell 902. In one embodiment, the distributing channels 907 are formed from circumferential grooves on the outer surface 903 of the core 901 or the inner surface 904 of the shell 902, and the common port 905 is a straight channel intersecting the circumferential distributing channels 907. In one embodiment, the multiple branch ports 906 are arranged in two lines parallel to the straight common port 905, such that lengths of the distributing channels 907 from a same common port (the visible or invisible common port) to the multiple branch ports 906 are the same. The fluid distribution device 9 further comprises input or output conduits 908 fluidly connected to the common ports 905 or branch ports 906. [0034] FIG. 10 illustrates a fluid distribution device 11, similar to the fluid distribution device 9, but in which two common ports 114 and 115 are parallel curved channels intersecting circumferential distributing channels 117. In the fluid distribution device 11, multiple branch ports 116 are arranged in curved lines parallel to the curved channels 114 and 115.

[0035] FIG. 11 illustrates a fluid distribution device 12, in which channels 127 for fluidly connecting each common port 124 or 125 with multiple branch ports 126 are helical channels.

[0036] FIG. 12 illustrates a fluid distribution device 13 including a shell 131 and a core 132. The shell 131 provides a hole 133 defining a circumferential inner surface 134. There are multiple ports 135 fluidly communicating with the hole 133. The core 132 provides a circumferential outer surface 136 closely matching the inner surface 134 of the shell 131. The core 132 further provides a hole 137 defining an inner surface 138, and multiple channels 139 corresponding to the multiple ports 135 of the shell 131. The multiple channels 139 each laterally extends through the core 132 to fluidly communicate with the hole 137, and has an opening on the outer surface 136 of the core 132 and an opening (not shown) on the inner surface 138 of the core 132. In one embodiment, the hole 137 of the core 132 functions as a common port. In assembly, the core 132 is received in the opening 133 of the shell 131, the outer surface 136 of the core 132 engages the inner surface 134 of the shell 131, and the channels 139 fluidly communicates with the corresponding ports 135 respectively. Thus the fluid distribution device 13 is capable of distributing a fluid inputted from the common port 137 to the multiple ports (branch ports) 135 through the channels 139, or collecting fluids from the branch ports 135 to the common port 137 through the channels 139. In one embodiment, the multiple channels 139 are micro-sized and are substantially the same in shape and size.

[0037] FIG. 13 illustrates a fluid distribution device 14, similar to the fluid distribution device 13, but with two common ports. In one embodiment, the fluid distribution device 14 includes a shell 141 and a core comprising two parts 142a and 142b. The shell 141 provides a through hole 143 defining a circumferential inner surface 144 and multiple ports 145 fluidly communicating with the through hole 143. The two parts 142a and 142b of the core are substantially the same, and each part provides a circumferential outer surface 146 closely matching the inner surface 144 of the shell 141. Similar to the core 132 of the fluid distribution device 13, each of the parts 142a and 142b further provides a hole 147 defining an inner surface 148 and multiple channels 147 corresponding to the multiple ports 145 of the shell 141. The multiple channels 149 on each part 142a or 142b laterally extend through the part to fluidly communicate with the hole 147, and each has an opening on the outer surface

146 and an opening (not shown) on the inner surface 148. Both the two holes

147 (only one is shown) respectively in the two parts 142a and 142b may function as common ports. The two parts 142a and 142b of the core are inserted into the through hole 143 respectively from two openings of the through hole 143. In assembly, the two parts of 142a and 142b the core are received in the though hole 143 of the shell 141 with their circumferential outer surfaces 146 engaging the inner surface 144 of the shell 141, and two corresponding channels 149 respectively on the two parts 142a and 142b communicating with a same one of the ports 145. Thus the fluid distribution device 14 is capable of distributing fluids inputted from the two common ports 147 to the multiple ports (branch ports) 145 through the channels 149, or collecting fluids from the branch ports 145 to the two common ports 147 through the channels 149. In one embodiment, the multiple channels 149 are micro-sized and are substantially the same in sizes.

[0038] The aforementioned fluid distribution devices may further include a sealing element adapted to enhance seal effect between the distributing channels or grooves. In one embodiment, the sealing element may be a film of metal or elastic material coated on the outer surface of the core or the inner surface of the shell. In one embodiment, the sealing element comprises ridges formed on the outer surface of the core or the inner surface of the shell and between adjacent ones of the distributing channels. In one embodiment, the sealing element comprises machining marks between adjacent ones of the distributing channels. As shown in FIG. 14, in one embodiment, the sealing element comprises notches 151 formed between adjacent ones of the distributing channels 150 and sealing materials (not shown) in the notches 151. The sealing material may be an elastic material, such as rubbers, or a glass solder, or one or more metal threads, or the like. [0039] In many cases, the multiple distributing channels of the aforementioned fluid distribution device have substantially equal flow resistances. A flow resistance difference between the multiple distributing channels may be measured by a flow rate difference of multiple flow paths in which the multiple distributing channels are respectively located. The flow rate difference may be denoted as (Q_maχ-Qmm)/Qav, wherein Q_max and Q_mm are respectively the maximum flow rate and the minimum flow rate among the multiple flow paths, and Q_av is the average of the flow rates of the multiple flow paths. The flow resistance difference between the multiple micro-channels also can be measured by a difference of times which are respectively used to passing a same volume of a same fluid through the multiple flow paths. The difference of times may be denoted as (T_max-T_mm)/T_av, wherein T_max is the maximum time, i.e., the time used to pass through the micro-channel with the highest flow resistance, and T_mm is minimum time, i.e., the time used to pass through the distributing channel with the lowest flow resistance, and T_av is the average of these times. Generally, if the flow rate difference or flow passing time difference of the multiple flow paths is controlled within 1%, the multiple distributing channels can be regarded as having substantially equal flow resistance.

[0040] The multiple distributing channels may be fabricated to be substantially the same both in shape and size to have substantially equal flow resistances. [0041] In many cases, the multiple distributing channels of the aforementioned fluid distribution device are micro-sized and have high flow resistances. For example, when a fluid distribution device is applied to uniformly distribute a reactant or the like to multiple parallel reactors in a parallel reaction system, the multiple branch ports of the fluid distribution device may be respectively connected upstream or downstream to the multiple parallel reactors. Each distributing channel that connects a said branch port with a common port is located in a flow path flowing through the respective reactor. If the multiple distributing channels are micro-sized and have substantially equal flow resistances much higher than other sections of the respective flow paths that they are located in, and therefore flow resistances of the other sections can be omitted, then flow resistances of the multiple flow paths are substantially the same. Therefore, flow rates of the multiple flow paths are substantially the same and the reactant can be uniformly distributed to the multiple reactors.

[0042] Generally, sizes larger than lmm are named as regular sizes, therefore channels with a minimum dimension of cross sections thereof larger than or equal to lmm are regular-sized channels, and channels with a minimum dimension of cross sections thereof smaller than lmm are micro-sized channels (micro-channels). A minimum dimension of a cross section refers to a minimum dimension in the cross section. For example, the minimum dimension for a rectangle cross section is a length of the shorter side of the rectangle, the minimum dimension for a circle cross section is a length of the diameter of the circle, the minimum dimension for a triangular cross section is a length of the minimum height of the triangle, and the minimum dimension for a cross section of an irregular shape is a length of the diameter of the maximal circle can be provided in the irregular cross section.

[0043] In one embodiment, the micro-sized distributing channels may be those with minimum dimensions smaller than 0.5mm, or more particularly, smaller than 0.1mm, or even smaller, for instance, smaller than 70μm, 50μm, 40μm, 30μm, 20μm, lOμm, 7μm, 5μm, 3μm, 2μm, lμm, 0.7μm, 0.5μm, 0.3μm, or O.lμm. Therefore, the micro-sized distributing channels may have minimum dimensions ranged in O.lμm- lmm, particularly in 0.5μm~0.5mm, or more particularly in lμm~100μm.

[0044] Methods suitable for fabricating the micro-channels include but are not limited to mechanical scratching, mechanical polishing, chemical corrosion, electrochemical corrosion (such as electro-polishing which is usually used in stainless steel substances), ion-bombardment, laser processing, found, dry etching, sandblasting, etc. Materials suitable to provide said micro-grooves/micro-channels include but are not limited to metals and their alloys (such as copper, stainless steel, etc.), silicon, glass, plastic, etc. [0045] The distributing channels may each have a size uniform along a length thereof or a size varying along a length thereof. For example, each of the distributing channels may have a gradually growing size which gradually grows along a length thereof from an end adjacent to the common port to the other end adjacent to the branch port. This kind of distributing channels (especially micro sized channels) is able to validly reduce the flow rate of the fluid flowing out of it.

[0046] The substantially circumferential outer or inner surface refers to a substantially closed surface such as a cylindrical surface, a conical surface, a prism surface or the like, which has a cross section of a closed or substantially closed line. Besides the cylindrical and conical shapes, the core may have any other shapes capable of providing a substantially circumferential outer surface, such as a frustum shape, a pyramid shape, a prism shape, and a curvilinear shape. Similarly, the shell can be any shape capable of providing a substantially circumferential inner surface, which closely matches the outer surface of the core.

[0047] The common ports and the branch ports may be much larger in size than the cross sections of the distributing channels, and therefore can be connected to outside conduits with any known sealing means such as screw thread and jointing, which is capable of withstanding high pressure. [0048] In the aforementioned fluid distribution devices, fluids apply pressure forces on the substantially circumferential outer surfaces of the cores and inner surfaces of the shells and opposed forces counteract each other. [0049] For example, referring to FIG. 15, as to a fluid distribution device with a cylindrical core and a corresponding shell, given that a fluid in position A apply a pressure force Fl to the circumferential inner surface of the shell and apply a pressure force F2 to the circumferential outer surface of the core, due to the pressure force F2, the core will apply a force F2¹ to the shell and receive a counterforce F2" from the shell, wherein F1=F2 and F2=F2'= F2". The forces Fl and F2¹ on the shell counteract each other, and the forces F2 and F2" counteract each other. Similarly, forces in other positions also can be counteracted. Therefore, the fluid distribution device can be used to handle fluids of any pressures if only the materials of the core and the shell can withstand the pressures. On the analogy of this, as to fluid distribution devices with cores of other shapes and corresponding shells, forces also can be counteracted or at least partially counteracted.

[0050] The aforementioned fluid distribution device, which includes a core with a circumferential outer surface and a shell with a circumferential inner surface, can be produced by a method comprising the following steps:

(1) fabricating a common port, multiple branch ports, and multiple micro-sized grooves or channels on the core or the shell;

(2) assembling the core and the shell in a manner that the outer surface of the core engages the inner surface of the shell and the micro-sized grooves or channels fluidly connect the common port with the branch ports respectively;

(3) feeding a fluid to the micro-sized grooves or channels and measuring flow rates in the micro-sized grooves or channels;

(4) eroding the micro-sized grooves or channels of relatively smaller flow rates with corrosive fluid; and

(5) repeating the previous two steps (3) and (4) until a flow rate difference of the micro-sized grooves or channels is below a predetermined value. [0051] Taking a manufacturing method of the fluid distribution device 3 as an example, the method may comprise the following steps:

(1) manufacturing a truncated cone shaped core, a shell and two end covers from stainless steel material, which shell is provided with holes for connecting outside inputting or outputting conduits;

(2) cleaning the core and shell in acetone with ultrasonic washer;

(3) covering a circumferential outer surface of the core with a layer of photoresist, and then roasting the covered core in an oven of about 80 ^°C for about 20 minutes;

(4) using a lithography mask with a threadlike rectangular transparent region exposed to an ultra-violet lamp to generate some ultraviolet exposed regions on the outer surface of the core, wherein the transparent region has a width of 15μm and a length longer than the axial length of the truncated cone shaped core;

(5) eroding the photoresist in the ultraviolet exposed regions in developer solution to generate regions for electrochemical polishing;

(6) roasting the residual photoresist on the core in an oven of about 120^°C in order to enhance corrosion resistance of the photoresist.

(7) fabricating micro-grooves at the eroded regions by electrochemical polishing;

(8) assembling the core into the shell and mounting the end covers to the shell through screw-thread engagement, such that the circumferential outer surface of the core closely engages the circumferential inner surface of the shell and the micro-sized grooves fluidly communicate with the respective holes in the shell;

(9) feeding a fluid to the micro-sized grooves and measuring flow rates in the micro-sized grooves;

(10) eroding the micro-sized grooves of relatively smaller flow rates with corrosive fluid including 50% hydrochloric acid solution and 20% mixed at a ratio of 1 :2; and

(11) repeating the steps (9) and (10) until a flow rate difference of the micro-sized channels is below a predetermined value.

Claims

CLAIMSWe claim:

1. A fluid distribution device, comprising: a core, a shell, a common port, and multiple branch ports, wherein the core has a substantially circumferential outer surface and the shell has a substantially circumferential inner surface engaging the outer surface of the core, and wherein distributing channels are formed between the outer surface of the core and the inner surface of the shell, the distributing channels forming fluid connections between the common port and respective ones of the multiple branch ports.

2. The fluid distribution device according to claim 1, wherein the distributing channels are micro-sized.

3. The fluid distribution device according to claim 2, wherein the micro-sized distributing channel has a minimum dimension less than 0.1 mm.

4. The fluid distribution device according to claim 3, wherein the micro-sized distributing channel has a minimum dimension less than 50 μm.

5. The fluid distributing device according to claim 1, wherein the distributing channels have substantially the same flow resistances.

6. The fluid distribution device according to claim 5, wherein the distributing channels are substantially the same in shape and size.

7. The fluid distribution device according to claim 1, wherein the distributing channels are formed by grooves on at least one of the outer surface of the core and the inner surface of the shell.

8. The fluid distribution device according to claim 7, wherein the core is substantially in the shape of one of a cylinder, a cone and a truncated cone, and the substantially circumferential outer surface of the core is a substantially cylindrical or conical surface.

9. The fluid distribution device according to claim 8, further comprising a sealing element adapted to enhance seal effect between the distributing channels.

10. The fluid distribution device according to claim 9, wherein the sealing element is a film of metal or elastic material coated on the outer surface of the core or the inner surface of the shell.

11. The fluid distribution device according to claim 9, wherein the sealing element comprises notches formed between adjacent ones of the grooves on the outer surface of the core or the inner surface of the shell, and sealing materials in the notches.

12. The fluid distribution device according to claim 9, wherein the sealing element comprises ridges formed on the outer surface of the core or the inner surface of the shell and between adjacent ones of the distributing channels.

13. The fluid distribution device according to claim 9, wherein the sealing element comprises machining marks between adjacent ones of the distributing channels.

14. The fluid distribution device according to claim 1, further comprising a second common port and second distributing channels respectively fluidly connecting the branch ports with the second common port, the second distributing channels having substantially equal flow resistances.

15. A fluid distribution device, comprising: a core, a shell, a common port, multiple branch ports, and micro-sized distributing channels fluidly connecting the common port with the multiple branch ports respectively, wherein the core has a substantially circumferential outer surface and a substantially circumferential inner surface, and the shell has a substantially circumferential inner surface tightly engaging the outer surface of the core, and wherein the micro-sized distributing channels each has an opening on the inner surface of the core and an opening on the outer surface of the core and extends through the core, fluid through the micro-sized distributing channels being kept from leaking between the outer surface of the core and the inner surface of the shell by tight engagement between the outer surface of the core and the inner surface of the shell.

16. The fluid distribution device according to claim 15, wherein the micro-sized distributing channel has a minimum dimension less than 0.1 mm.

17. The fluid distribution device according to claim 16, wherein the micro-sized distributing channel has a minimum dimension less than 50 μm.

18. A method for manufacturing a fluid distribution device including a core having a substantially circumferential outer surface and a shell having a substantially circumferential inner surface, comprising the following steps:

fabricating a common port, multiple branch ports, and micro-sized channels on the core or the shell;

assembling the core and the shell in a manner that the outer surface of the core engages the inner surface of the shell and the micro-sized channels fluidly connect the common port with the branch ports respectively;

feeding a fluid into the micro-sized channels and measuring flow rates in the micro-sized channels;

eroding the micro-sized channels having relatively smaller flow rates by corrosive fluid; and

repeating the previous two steps until a flow rate difference of the micro-sized channels is below a predetermined value.