US20150159879A1

US20150159879A1 - Biomass fuel oven

Info

Publication number: US20150159879A1
Application number: US14/396,163
Authority: US
Inventors: Hongfeng Zhu; Qianxi Chen
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-04-23
Filing date: 2012-04-23
Publication date: 2015-06-11
Also published as: WO2013159267A1; CN104067050A

Abstract

A biomass fuel oven for use with biomass fuel granule. The oven has a body which is able to be levelly placed on the ground. The body has a combustion cabinet and an auxiliary equipment cabinet. The combustion cabinet has a burner received therein. The burner has a fire grate. A burning zone is defined beyond the fire grate and an air supply zone is defined below the fire grate. A plurality of air vents is defined in the fire grate. An air supply device is provided at the burning zone. The air supply device has a tubular inner wall and an air chamber surrounding the tubular inner wall. The air supply zone is in communication to the air chamber and is supplied air by an air blower via an air duct.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention
The invention relates to an oven for use with biomass fuel, and more particularly, to an oven using granule made by smashed and then briquetted straw, bits of wood, or crop stalks and having a turbulent flow air supply in a flame zone to highly increase a use ratio of energy.
2. Description of Related Art
Biomass fuel is granule made by smashed and then briquetted straw, bits of wood, or crop stalks. As a new energy solution, biomass fuel has wider and wider been used because it is hygienic, environmental, high efficient, and economic.
A conventional biomass fuel oven is disclosed in a PCT patent application PCT/CN2012/01746 “A High Performance Oven” by this applicant. As shown in FIGS. 14 and 15, the oven has a body 9 having a combustion cabinet 91 and an auxiliary equipment cabinet 92. The combustion cabinet has a burner 93 received therein. The burner 93 has a fire grate 931. A burning zone 932 is defined beyond the tire grate 931 and an air supply zone 933 is defined below the fire grate 931. A flame zone 934 is above the burning zone 932 of the burner 93. An air supply device 94 is provided at the flame zone 934. The air supply device 94 has a tubular inner wall 941, an enclosed air chamber 942, and an air duct 943 connecting the air chamber 942 and the air supply zone 933. A plurality of deflecting devices 95 are longitudinally formed on the tubular inner wall 941 of the air supply device 94. Each deflecting device 95 has a long slit 951. On an outer surface of the tubular inner wall 941, a deflector 952 are formed all on a same side, left or right, of the long slits 951. Each deflector 952 extends towards corresponding long slit 951 and having an angle with respect to the outer surface of the tubular wall 941. The angle is between 0 and 90 degree.
The aforementioned way of air supplying resolves the problem of air interference between flows from each deflecting device, but the oven still has technical drawbacks. The deflecting device 95 forms an air flow going spirally upward like a tornado in the flame zone 934 in the tubular wall 941 of the air supply device 94. The spiral air flow resolves the interference between flows of supplying air and provides oxygen for combustion. However, just because of the unidirectionality of the flow of the supplying air, the oxygen in the supplying air is not able to completely mix with a burning gas, which results in an incomplete burning. Secondly, also because of the unidirectionality of the flow, without any impediment, an upgoing velocity of flow will be quick, which will quickly take away heat and some incompletely burn gas. This will bring further waste of energy. Third, since the incomplete burning caused by above two reasons, a carbon granule density of the incomplete burning gas of the waste gas will be high. An outward phenomena is thick smoke. Forth, heat in the flame zone 934 in the air supply device 94 is always being taken away quickly and no high temperature is able to be produced.
Furthermore, for conventional biomass fuel ovens, form of the flames in the hearth 91 is relatively disperse and not controllable. It is difficult to concentrate the flames to increase a use ratio of heat energy.

BRIEF SUMMARY OF THE INVENTION

The main object of the invention is to provide a biomass fuel oven which is able to avoid interference between supplying air flows, and at the same time, to completely mix oxygen in the supplying air with burning gas to make a fuller combustion.
Another object of the invention is to provide a biomass fuel oven which is able to slow down an upgoing velocity of the burning gas in the flame zone to achieve a higher temperature for heating.
In order to accomplish the above objects, the present invention provides a biomass fuel oven for use with biomass fuel granule. The oven has a body which is able to be levelly placed on the ground. The body has a top panel and a side panel extending downward to the ground from the top panel. The body further has a combustion cabinet and an auxiliary equipment cabinet. The combustion cabinet has a burner received therein. The burner has a fire grate. A burning zone is defined beyond the fire grate and an air supply zone is defined below the fire grate. A plurality of air vents is defined in the fire grate. An air supply device is provided at the burning zone. The air supply device has a tubular inner wall and an air chamber surrounding the tubular inner wall. The air supply zone is in communication to the air chamber and is supplied air by an air blower via an air duct, the auxiliary equipment cabinet has an electrical equipment received therein. The electrical equipment has the air blower, a power supply, and a switch. At least one row of clockwise deflecting devices and at least one row of anticlockwise deflecting devices are formed on the tubular inner wall of the air supply device.
The beneficiary effects of the invention are as follows. The air flows entering into the flame zone respectively from the clockwise and anticlockwise deflecting devices are able to fully mix oxygen in the supplying air with burning gas, which makes a more complete combustion and increases use ratio of energy. At the same time, compared with the conventional single spiral air flow, an interference between the two countering air flows decrease an up-going velocity of high temperature of burning gas. A longer lingering time in the flame zone of the burning gas will be able to obtain a higher burning temperature. In testing experiments, the oven of the invention is able to increase temperature by 20-30 percent compared to conventional biomass fuel ovens. Thirdly, because of the complete combustion, a density of carbon granule in the waste gas decrease greatly. There is no more black smoke produced from flames.
These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a schematic perspective view of the preferred embodiment of the invention.

FIG. 2 is an exploded perspective view of the oven shown in FIG. 1.

FIG. 3 a is a top plane view of a the oven shown in FIG. 1.

FIG. 3 b is a cross-sectional view along direction A-A shown in FIG. 3 a.

FIG. 4 is a perspective partial view of a burner and an tubular inner wall of an air supply device.

FIG. 5 is a top plane view of the burner and the tubular inner wall of the air supply device.

FIG. 6 is a circuit diagram of an electrical equipment of the oven shown in FIG. 1.

FIG. 7 is a schematic perspective view of another embodiment of the invention.

FIG. 8 is an exploded perspective view of the oven shown in FIG. 7.

FIG. 9 is a cross-sectional plane view of the oven shown in FIG. 7.

FIG. 10 is an enlarged perspective partial view of the air supply device shown in FIG. 7.

FIG. 11 is an enlarged plane partial view of the tubular inner wall shown in FIG. 10.

FIG. 12 is a circuit diagram of an electrical equipment of the oven shown in FIG. 7.

FIG. 13 a through 13 c are enlarged perspective view of three other air supply devices of the invention.

FIG. 14 is a cross-sectional plane view of a conventional biomass fuel oven having air supply device. And,

FIG. 15 is an enlarged plane view of a tubular inner wall of the air supply device shown in FIG. 14.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic perspective view of the preferred embodiment of a biomass fuel oven of the invention. The oven has a body 1 which is able to be levelly placed on the ground. The body 1 has a top panel 11 and a side panel 12 extending downward to the ground from the top panel 11. The body 1 has a combustion cabinet 10 and an auxiliary equipment cabinet 20 received therein.
Together with reference to FIGS. 3 a and 3 b, the combustion cabinet 10 has a burner 30 and an air supply device 40 received therein. The burner 30 has a fire grate 31. A burning zone 32 is defined beyond the fire grate 31 and an air supply zone 33 is defined below the fire grate 31. A plurality of air vents 311 are defined in the fire grate 31. The air supply device 40 has a tubular inner wall 41 and an air chamber 42 surrounding the tubular inner wall 41. In this embodiment, the air supply zone 33 is in communication to the air chamber 42, and being supplied air by an air blower 51 via an air duct 34. The tubular inner wall 41 defines a flame zone 35 therewithin by the wall thereof.
Together with reference to FIGS. 4 and 5, at least one row of clockwise deflecting devices 43 and at least one row of anticlockwise deflecting devices 44 are formed on the tubular inner wall 41. Each row of clockwise deflecting devices 43 has a plurality of first slit 431. On an outer surface of the tubular inner wall 41, a plurality of first deflectors 432 is respectively formed on one same side, left or right, of the first slits 431. Each first deflector 432 extends towards corresponding first slit 431 and having an angle “a” with respect to an outer surface of the tubular wall 41. Angle “a” is between 0 and 90 degree, preferably 45 degree. In the shown embodiment, all first deflectors 432 are on the left side of corresponding first slit 431 and extend towards corresponding first slit 431, i.e., towards right. Each row of anticlockwise deflecting devices 44 has a plurality of second slit 441. On the outer surface of the tubular inner wall 41, a plurality of second deflectors 442 is respectively formed on one same side different from the side of the first deflectors 432 of the second slits 441. Each second deflector 442 extends towards corresponding second slit 441 and having an angle “b” with respect to an outer surface of the tubular wall 41. Angle “b” is between 0 and 90 degree, preferably 45 degree. In the shown embodiment, all second deflectors 442 are on the right side of corresponding second slit 441 and extend towards corresponding second slit 441, i.e., towards left.
In the shown embodiment, the auxiliary equipment cabinet 20 has an electrical equipment 50 received therein. The electrical equipment 50, as shown in FIG. 6, has the air blower 51 for supplying air to the air supply zone 33 of the burner 30 and the air chamber 42, a power supply 52, a switch 53 and a power light 54. The power supply 52 may be an independent alternating current/direct current power supply 521, having or having not a storage battery 522 in parallel as auxiliary. Either the alternating current/direct current power supply 521 or the storage battery 522 is able to supply power independently. The switch 53 is installed on the side panel 12 and able to control the power supply of whole circuit. The power light 54 is also installed on the side panel 12 near the switch 53 and used to indict status of power supply.
Fuel 70 is biomass fuel granule made by smashed and then briquetted straw, bits of wood, or crop stalks.
In use, a user is able to first stably place the body 1 of the oven on the ground where is desirable and then load fuel 70 onto the fire grate 31 of the burner 30 through the flame zone 35 defined by the tubular inner wall 41 of the air supply device 40 in the combustion cabinet 10. When the user turns on the switch 53, the power light 54 turns up, which means the electrical circuit is closed and the oven starts to work. At this time, the user is able to ignite the fuel 70 by throwing a burning alcohol cotton ball onto the fuel 70 on the fire grate 31. Also at this time, the air blower 51 start to supply air to the air supply zone 33 and the air chamber 42. Air entering the air supply zone 33 through the air vents 311 in the fire grate 31 provides oxygen for combustion of the fuel 70 in the burning zone 32. Air entering the air chamber 42 goes into the flame zone 35 defined by the tubular inner wall 41 through all clockwise deflecting devices 43 and all anticlockwise deflecting devices 44. Methane gas is created in a process of burning of the fuel 70. With air flow produced by the air blower 51, the methane gas burns into flames. Different to the conventional way of air supplying to the flame zone 35, air entering the flame zone 35 through each clockwise deflecting device 43 unidirectionally flows clockwise after passing by each first deflector 432. Therefore, the air in the flame zone 35 from the clockwise deflecting device 43 is in a form of unidirectional spiral. At the same time, air entering the flame zone 35 through each anticlockwise deflecting device 44 unidirectionally flows anticlockwise after passing by each second deflector 442. Therefore, the air in the flame zone 35 from the anticlockwise deflecting device 44 is in a form of unidirectional spiral opposite to the air flow from the clockwise deflecting device 43. The air flows entering into the flame zone 35 respectively from the clockwise and anticlockwise deflecting devices 43 and 44 are able to fully mix oxygen in the supplying air with burning gas, which makes a more complete combustion and increases use ratio of energy. At the same time, compared with the conventional single spiral air flow, an interference between the two countering air flows decrease an up-going velocity of high temperature of burning gas. A longer lingering time in the flame zone 35 of the burning gas will be able to obtain a higher burning temperature. In testing experiments, the oven of the invention is able to increase temperature by 20-30 percent compared to conventional biomass fuel ovens.
The tubular inner wall 41 may further has a plurality of turbulent air supplier 45 defined therein. The turbulent air supplier 45 may be any mechanism which is able to supply air to the flame zone 35 in the tubular inner wall 41. As shown in FIG. 4, the embodiment of the turbulent air supplier 45 has a plurality of turbulent holes 451 defined in the tubular inner wall 41. After the air blower 51 is turned on, supplying air enters into the flame zone 35 defined by the tubular inner wall 41 not only through the clockwise and the anticlockwise deflecting devices 43 and 44, but also through the turbulent holes 451 of the turbulent air supplier 45. The air flows entering into the flame zone 35 through the turbulent air supplier 45 are able to further mix up oxygen in the supplying air and the burning gas and further increase the use ratio of energy. At the same time, the air flows entering into the flame zone 35 through the turbulent air supplier 45 are able to further decrease the up-going velocity of the burning gas, thus further increase the temperature of the burning in the oven. Shown in FIGS. 13 a, 13 b and 13 c are three other embodiments of the turbulent air supplier 45. In the embodiment shown in FIG. 13 a, the turbulent air supplier 45 is a thin tube 452 in communication to the air chamber 42 and having a plurality of turbulent holes 451′ defined therein. In the embodiment shown in FIG. 13 b, the turbulent air supplier 45 is a plurality of thin tubes 453 extending into the tubular inner wall 41 and having turbulent holes 451″ at free ends thereof. In the embodiment shown in FIG. 13 c, the turbulent air supplier 45 is two thin tubes 454 in communication to the air chamber 42 extending into the tubular inner wall 41 and being in communication to a circular thin pipe 455 having a plurality of turbulent holes 451′″.
Shown in FIGS. 7, 8 and 9 is another embodiment of the invention. Compared with the preferred embodiment, the air supply zone 33 of the burner 30 in this embodiment is not directly in communication to the air chamber 42 of the air supply device 40. The air supply zone 33 and the air chamber 42 are respectively in communication to the air blower 51. A second difference is that besides the electrical equipment 50, the auxiliary equipment cabinet 20 further has a fuel supply mechanism 60 received therein. The fuel supply mechanism 60 has a hopper 61 having a lower outlet 611, a fuel tube 62 having one end in communication to the lower outlet 611 of the hopper 61 and a free end extending into the burning zone 32, and a rotary vane feeder 63 rotatably received in the fuel tube 62. The electrical equipment 50, as shown in FIG. 12, has the air blower 51 for supplying air to the air supply zone 33 of the burner 30 and the air chamber 42, a power supply 52, a switch 53, a power light 54, and a feeding motor 55 for driving the rotary vane feeder 63. The switch 53 is installed on the side panel 12 and able to control the power supply of whole circuit. The power light 54 is also installed on the side panel 12 near the switch 53 and used to indict status of power supply. A door 121 is able to be provided in the side panel 12.
A shape of the tubular inner wall 41 does not have to be strictly tubular having a single diameter as shown in the preferred embodiment but be able to be any shape which is basically a round tube such as a tube having wave or a complex shape as an inner tube of a washing machine, as shown in FIGS. 10 and 11. The tubular inner wall 41 shown in FIG. 7 has a shape of cone having a diameter of end being greater than a diameter of the other end. Also in the embodiment shown in FIG. 7, all the first and the second slits 431 and 441 of the clockwise and the anticlockwise deflecting devices 43 and 44 are a thin slit having an angle “c” with respect to a generatrix “g” of the tubular inner wall 41. Angle “c” is between 0 and 45 degree, preferably 15 degree.
When the user needs to stop the burning, he is able to turn off the switch 64, and the power light 65 goes out. The feeding motor 61 stops rotating, and the air blower 62 ceases. As there is no new supply of fuel 70, the fuel 70 in the burning zone 32 will burn up in a very short time period. The user then is able to open the door 121 and collect ash in the air supply zone 33. Outer region of the fire grate 31 may be oblique upward in a certain degree in order to form a central depression. The central depression is useful to gather fuel together to avoid black smoke caused by insufficient burning of the outer region fuel 70.
From above description, it is seen that the objects of the present invention have been fully and effectively accomplished. Embodiment of the invention has been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from the invention's principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.

Claims

1. A biomass fuel oven for use with biomass fuel (70) granule and comprising:

a body (1) which is able to be levelly placed on the ground, said body (1) having a top panel (11) and a side panel (12) extending downward to the ground from said top panel (11) and having a combustion cabinet (10) and an auxiliary equipment cabinet (20), said combustion cabinet (10) having a burner (30) received therein, said burner (30) having a fire grate (31), a burning zone (32) being defined beyond said fire grate (31), an air supply zone (33) being defined below said fire grate (31), a plurality of air vents (311) being defined in said fire grate (31), an air supply device (40) being provided at said burning zone (32), said air supply device (40) having a tubular inner wall (41) and an air chamber (42) surrounding said tubular inner wall (41), said air supply zone (33) being in communication to said air chamber (42) and being supplied air by an air blower (51) via an air duct (34), said auxiliary equipment cabinet (20) having an electrical equipment (50) received therein, said electrical equipment (50) having said air blower (51), a power supply (52), and a switch (53), at least one row of clockwise deflecting devices (43) and at least one row of anticlockwise deflecting devices (44) are formed on said tubular inner wall (41) of said air supply device (40).

2. The biomass fuel oven as claimed in claim 1, wherein each row of said clockwise deflecting devices (43) has a plurality of first slit (431), on an outer surface of said tubular inner wall (41), a plurality of first deflectors (432) being respectively formed on one same side of said first slits (431), each said first deflector (432) extends towards corresponding said first slit (431) and having an angle “a” with respect to an outer surface of said tubular wall (41), angle “a” being between 0 and 90 degree, and each row of said anticlockwise deflecting devices (44) has a plurality of second slit (441), on said outer surface of said tubular inner wall (41), a plurality of second deflectors (442) being respectively formed on one same side different from said side of said first deflectors (432) of said second slits (441), each said second deflector (442) extends towards corresponding said second slit (441) and having an angle “b” with respect to said outer surface of the tubular wall, angle “b” being between 0 and 90 degree.

3. The biomass fuel oven as claimed in claim 1, wherein said tubular inner wall (41) further has a plurality of turbulent air supplier (45) defined therein.

4. The biomass fuel oven as claimed in claim 2, wherein said tubular inner wall (41) further has a plurality of turbulent air supplier (45) defined therein.

5. The biomass fuel oven as claimed in claim 3, wherein said turbulent air supplier (45) has a plurality of turbulent holes (451) defined in said tubular inner wall (41).

6. The biomass fuel oven as claimed in claim 4, wherein said turbulent air supplier (45) has a plurality of turbulent holes (451) defined in said tubular inner wall (41).

7. The biomass fuel oven as claimed in claim 3, wherein said turbulent air supplier (45) is a thin tube (452) in communication to said air chamber (42) and having a plurality of turbulent holes (451′) defined therein.

8. The biomass fuel oven as claimed in claim 4, wherein said turbulent air supplier (45) is a thin tube (452) in communication to said air chamber (42) and having a plurality of turbulent holes (451′) defined therein.

9. The biomass fuel oven as claimed in claim 3, wherein said turbulent air supplier (45) is a plurality of thin tubes (453) extending into said tubular inner wall (41) and having turbulent holes (451″) at free ends thereof.

10. The biomass fuel oven as claimed in claim 4, wherein said turbulent air supplier (45) is a plurality of thin tubes (453) extending into said tubular inner wall (41) and having turbulent holes (451″) at free ends thereof.

11. The biomass fuel oven as claimed in claim 3, wherein said turbulent air supplier (45) is two thin tubes (454) in communication to said air chamber (42) extending into said tubular inner wall (41) and being in communication to a circular thin pipe (455) having a plurality of turbulent holes (451′″).

12. The biomass fuel oven as claimed in claim 4, wherein said turbulent air supplier (45) is two thin tubes (454) in communication to said air chamber (42) extending into said tubular inner wall (41) and being in communication to a circular thin pipe (455) having a plurality of turbulent holes (451′″).

13. A biomass fuel oven for use with biomass fuel (70) granule and comprising:

a body (1) which is able to be levelly placed on the ground, said body (1) having a top panel (11) and a side panel (12) extending downward to the ground from the top panel (11) and having a combustion cabinet (10) and an auxiliary equipment cabinet (20), said combustion cabinet (10) having a burner (30) received therein, said burner (30) having a fire grate (31), a burning zone (32) being defined beyond said fire grate (31), an air supply zone (33) being defined below said fire grate (31), a plurality of air vents (311) being defined in said fire grate (31), an air supply device (40) being provided at said burning zone (32), said air supply device (40) having a tubular inner wall (41) and an air chamber (42) surrounding said tubular inner wall (41), said air supply zone (33) and said air chamber (42) being respectively in communication to said air blower (51), said auxiliary equipment cabinet (20) having an electrical equipment (50) and a fuel supply mechanism (60) received therein, said fuel supply mechanism (60) has a hopper (61) having a lower outlet (611), a fuel tube (62) having one end in communication to said lower outlet (611) of said hopper (61) and a free end extending into said burning zone (32), and a rotary vane feeder 63 rotatably received in said fuel tube (62), said electrical equipment (50) having said air blower (51), a power supply (52), and a switch (53), at least one row of clockwise deflecting devices (43) and at least one row of anticlockwise deflecting devices (44) are formed on the tubular inner wall (41) of the air supply device (40).

14. The biomass fuel oven as claimed in claim 13, wherein each row of said clockwise deflecting devices (43) has a plurality of first slit (431), on an outer surface of said tubular inner wall (41), a plurality of first deflectors (432) being respectively formed on one same side of said first slits (431), each said first deflector (432) extends towards corresponding said first slit (431) and having an angle “a” with respect to an outer surface of said tubular wall (41), angle “a” being between 0 and 90 degree, and each row of said anticlockwise deflecting devices (44) has a plurality of second slit (441), on said outer surface of said tubular inner wall (41), a plurality of second deflectors (442) being respectively formed on one same side different from said side of said first deflectors (432) of said second slits (441), each said second deflector (442) extends towards corresponding said second slit (441) and having an angle “b” with respect to said outer surface of the tubular wall, angle “b” being between 0 and 90 degree.

15. The biomass fuel oven as claimed in claim 13, wherein said tubular inner wall (41) further has a plurality of turbulent air supplier (45) defined therein.

16. The biomass fuel oven as claimed in claim 14, wherein said tubular inner wall (41) further has a plurality of turbulent air supplier (45) defined therein.

17. The biomass fuel oven as claimed in claim 15, wherein said turbulent air supplier (45) has a plurality of turbulent holes (451) defined in said tubular inner wall (41).

18. The biomass fuel oven as claimed in claim 16, wherein said turbulent air supplier (45) has a plurality of turbulent holes (451) defined in said tubular inner wall (41).

19. The biomass fuel oven as claimed in claim 15, wherein said turbulent air supplier (45) is a thin tube (452) in communication to said air chamber (42) and having a plurality of turbulent holes (451′) defined therein.

20. The biomass fuel oven as claimed in claim 16, wherein said turbulent air supplier (45) is a thin tube (452) in communication to said air chamber (42) and having a plurality of turbulent holes (451′) defined therein.

21. The biomass fuel oven as claimed in claim 15, wherein said turbulent air supplier (45) is a plurality of thin tubes (453) extending into said tubular inner wall (41) and having turbulent holes (451″) at free ends thereof.

22. The biomass fuel oven as claimed in claim 16, wherein said turbulent air supplier (45) is a plurality of thin tubes (453) extending into said tubular inner wall (41) and having turbulent holes (451″) at free ends thereof.

23. The biomass fuel oven as claimed in claim 15, wherein said turbulent air supplier (45) is two thin tubes (454) in communication to said air chamber (42) extending into said tubular inner wall (41) and being in communication to a circular thin pipe (455) having a plurality of turbulent holes (451′″).

24. The biomass fuel oven as claimed in claim 16, wherein said turbulent air supplier (45) is two thin tubes (454) in communication to said air chamber (42) extending into said tubular inner wall (41) and being in communication to a circular thin pipe (455) having a plurality of turbulent holes (451′″).