JP2015094018A - Oxygen reduction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oxygen reduction device capable of exhausting oxygen generated at an anode without reducing the efficiency of the electrolysis of water in the anode.SOLUTION: Provided is an oxygen reduction device 200 performing oxygen reduction by a solid polymer electrolyte membrane method, in which an anode 208 is provided with a water feed sheet 222 made of a nonwoven fabric via a spacer 211, the lower part of the water feed sheet 222 is immersed into a water storage tank 314, and the device has an opening part 320 not covered with the membrane of water when the water feed sheet 222 sucks up water.

Description

  Embodiments described herein relate generally to an oxygen reduction device.

  Conventionally, the CA (Controlled Atmosphere) storage method includes a gas replacement method often used in the food industry, a vacuum method for reducing oxygen by reducing the pressure, and oxygen in the oxygen reduction chamber using a solid polymer electrolyte membrane. There are a solid polymer electrolyte method to decrease, an adsorption method using an oxygen adsorbent, and the like.

  Among these, the oxygen reduction device using the solid polymer electrolyte membrane method electrolyzes water at the anode to produce hydrogen ions, and the hydrogen ions move through the solid polymer electrolyte membrane and reach the cathode. Oxygen is consumed by producing water by reacting with oxygen in the oxygen chamber. Therefore, there is a merit that the pressure change is small and the strength of the oxygen-reducing chamber is not necessary.

JP 2004-218924 A JP-A-5-227881

  In the oxygen reduction apparatus using the above-described solid polymer electrolyte membrane method, a water supply sheet is disposed near the anode in order to supply water to the anode, and the lower end of the water supply sheet is eroded by water. Although this water supply sheet is a porous body, since the pores of the porous body are filled with water, there is a phenomenon that oxygen is not discharged and the pressure rises due to the oxygen that is not discharged. If oxygen is not discharged, the supply of water to the anode will be delayed, and the efficiency of the reaction by electrolysis will decrease, so that the current flowing in the solid polymer electrolyte membrane will decrease and the reaction rate of oxygen reduction will decrease was there.

  Therefore, in view of the above problems, an embodiment of the present invention aims to provide an oxygen reduction device that can discharge oxygen generated at an anode without reducing the efficiency of water electrolysis at the anode.

  An embodiment of the present invention is provided with a solid polymer electrolyte membrane, an anode provided on one side of the solid polymer electrolyte membrane, and the other side of the solid polymer electrolyte membrane, and leads to a reduced oxygen space. A cathode, an anode current collector for energizing the anode, a cathode current collector for energizing the cathode, a water supply sheet provided on the anode side, and provided between the anode current collector and the water supply sheet And a water storage tank for supplying water to the water supply sheet, and the water supply sheet is covered with a water film in a state where the lower part is immersed in the water of the water storage tank. An oxygen reduction device with no opening.

  An embodiment of the present invention includes a solid polymer electrolyte membrane, an anode provided on one side of the solid polymer electrolyte membrane, and an oxygen reduction space provided on the other side of the solid polymer electrolyte membrane. A cathode communicating with the anode, an anode current collector for energizing the anode, a cathode current collector for energizing the cathode, a water supply sheet provided on the anode side, the anode current collector and the water supply sheet, A plate-shaped spacer provided between the anode current collector, a water supply opening provided from the anode current collector to the water supply sheet, and an oxygen discharge opening provided at an edge of the spacer. And an oxygen reduction device having a notch.

It is a longitudinal cross-sectional view of the refrigerator of Embodiment 1. It is a longitudinal cross-sectional view of an oxygen reducing device. It is a disassembled perspective view of an oxygen reduction unit. It is a disassembled perspective view of an oxygen reducing device. It is a perspective view of a front fixing member. It is a perspective view of a back fixing member. It is the longitudinal cross-sectional view seen from the front of a water supply apparatus. It is a disassembled perspective view of the oxygen reduction unit of Embodiment 2. It is a disassembled perspective view of the oxygen reduction unit of Embodiment 3.

  Hereinafter, an oxygen reduction device 200 for a refrigerator according to an embodiment will be described with reference to the drawings.

Embodiment 1

  The refrigerator 10 of Embodiment 1 is demonstrated based on FIGS. The refrigerator 10 of this embodiment has an oxygen reduction chamber 100, and the oxygen reduction chamber 100 has an oxygen reduction device 200.

(1) Structure of refrigerator 10 The structure of the refrigerator 10 is demonstrated based on FIG. FIG. 1 is a longitudinal sectional view as seen from the side of the entire refrigerator 10.

  The cabinet 12 of the refrigerator 10 is a heat insulation box, and is formed of an inner box and an outer box, and a heat insulating material is filled between the inner box and the outer box. The inside of the cabinet 12 has a refrigerator compartment 14, a vegetable compartment 16, a small freezer compartment 18 and a freezer compartment 20 in order from the top, and an ice making room is provided beside the small freezer compartment 18. A heat insulating partition 36 is provided between the vegetable compartment 16, the small freezer compartment 18 and the ice making compartment. The refrigerator compartment 14 and the vegetable compartment 16 are partitioned by a horizontal partition 38. A double door 14a is provided in front of the refrigerator compartment 14, and drawer doors 16a, 18a and 20a are provided in the vegetable compartment 16, the small freezer compartment 18, the freezer compartment 20 and the ice making compartment, respectively.

  A machine room 22 is provided at the bottom of the back surface of the cabinet 12, and a compressor 24 and the like constituting the refrigeration cycle are placed thereon. A control plate 26 is provided on the upper back of the machine room 22.

  A refrigeration evaporator (hereinafter referred to as “R EVA”) 28 is provided from the lower back of the refrigerator compartment 14 to the back of the vegetable compartment 16, and a refrigeration blower (hereinafter referred to as “R fan”) 30 is provided below the evaporator. Is provided. The R EVA 28 and the R fan 30 are disposed in an R EVA chamber 17 formed by the EVA cover 15. The R-eva 28 is provided with a tray 54 for collecting defrost water generated by the R-eva 28.

  A freezing evaporator (hereinafter referred to as “F-eva”) 32 is provided in the F-evaporation chamber 29 from the back of the small freezer 18 to the back of the freezing chamber 20, and a freezing blower (hereinafter referred to as “F”) is provided above it. 34) is provided. The cold air cooled by the R evaporator 28 is sent to the refrigerator compartment 14 and the vegetable compartment 16 by the R fan 30. The cold air cooled by the F-evapor 32 is blown by the F fan 34 to the small freezer 18, ice making room, and freezer 20.

  A refrigeration chamber sensor 31 that detects the internal temperature of the refrigeration chamber 14 is provided on the back surface of the refrigeration chamber 14. Is provided.

  As shown in FIG. 1, the refrigerator compartment 14 is provided with a plurality of shelves 40, and a chilled chamber 44 having a drawer-type chilled container 42 is provided at the lower part. The chilled chamber 44 is a low temperature chamber and stores meat and fish. A plurality of door pockets 46 are provided on the back surface of the door 14 a of the refrigerator compartment 14. In the vegetable compartment 16, a drawer-type vegetable container 48 is provided.

  A hypoxic chamber 100 is provided at the rear of the partition 38 that hits the ceiling of the vegetable compartment 16. The oxygen reduction chamber 100 is provided with a pull-out type oxygen reduction container 102, and a door 104 is provided in front of the oxygen reduction container 102. When the oxygen reduction container 102 is housed in the oxygen reduction chamber 100, the door 104 seals the front opening of the oxygen reduction chamber 100, and the interior of the oxygen reduction chamber 100 is almost sealed. An oxygen reduction device 200 is attached to the back surface of the oxygen reduction chamber 100.

(2) Oxygen reduction device 200
The oxygen reduction device 200 includes a case 204 having heat insulating properties and an oxygen reduction unit 202 housed therein. The oxygen reduction unit 202 will be described with reference to FIGS. In FIGS. 2 to 4, the thickness of each member is thin, but the thickness is illustrated in an enlarged manner for easy understanding.

  A solid polymer electrolyte membrane (hereinafter simply referred to as “electrolyte membrane”) 206 is provided in the vertical direction, an anode 208 is provided at the rear of the electrolyte membrane 206, and a cathode 210 is provided at the front of the electrolyte membrane 206. Yes. The cathode 210 is a laminate of a carbon catalyst and carbon paper. Further, platinum catalyst is supported on the anode 208 and the cathode 210, respectively. The electrolyte membrane 206, the anode 208, and the cathode 210 are integrally joined using a hot press or the like to form a hypoxic cell. An anode current collector 212 is provided behind the anode 208, and a cathode current collector 214 is provided in front of the cathode 210. Both current collectors 212 and 214 have slit-like openings 216 and 218, respectively, through which gas passes. The anode current collector 212 applies positive current to the anode 208, and the cathode current collector 214 performs negative current to the cathode 210. Both current collectors 212 and 214 are energized from electric wires (not shown). In addition, an insulator 220 is provided between the current collectors 212 and 214 in order to prevent the current collectors 212 and 214 from contacting each other. The insulator 220 has a frame shape, and the electrolyte membrane 206, the anode 208, and the cathode 210 are accommodated therein.

  A water supply sheet 222 made of a nonwoven fabric is disposed behind the anode current collector 212 on the anode 208 side.

  A plate-like spacer 211 is disposed between the anode current collector 212 and the water supply sheet 222. The spacer 211 has a plurality of slit-shaped water supply openings 213. The spacer 211 has a thickness of 1 mm, and forms a certain space A between the anode current collector 212 and the water supply sheet 222.

  The members stacked in order as described above are sandwiched and fixed by a pair of front and rear rear fixing members 224 and a front fixing member 226. The rear fixing member 224 disposed on the anode 208 side has a storage recess 228 for storing the stacked members, and a groove 230 is provided on the upper portion to project the protruding pieces of both current collectors 212 and 214. . In addition, a slit-like opening 232 through which gas passes is opened at the center of the rear fixing member 224.

  The front fixing member 226 attached to the cathode side has a plate shape, and has a slit-like opening 234 through which gas passes in the center. As shown in FIG. 2, the slit-shaped opening 234 is inclined so as to become narrower as it is later, unlike the cross-sectional area on the front side and the cross-sectional area on the rear side. This is to make it easier to send air to the cathode current collector 214.

  As shown in FIG. 3, the rear fixing member 224 and the front fixing member 226 are screwed by screws (not shown). A unit in which these members are integrated is referred to as an “oxygen reduction unit 202”. Note that the protruding pieces of both current collectors 212 and 214 protrude from the upper part of the oxygen reduction unit 202, and the water supply sheet 222 hangs from the lower part.

(3) Case 204
As shown in FIG. 4, the oxygen reduction unit 202 described above is accommodated inside a case 204 having a box-shaped heat insulating property. As shown in FIGS. 4 to 6, the case 204 includes a rectangular parallelepiped front case 236, a rear case 238, a frame-like middle case 240 sandwiched between the front case 236 and the rear case 238. . A front case 236 is arranged on the cathode side of the oxygen reduction unit 202, a rear case 238 is arranged on the anode side, and the front case 236, the rear case 238, and the middle case 240 are not shown in the state in which the oxygen reduction unit 202 is stored. Screwed.

  The front case 236 will be described with reference to FIGS. A square-shaped reaction recess 244 is provided at the center of the rear surface of the front case 236 having heat insulation properties. Further, a groove-shaped upper flow path 246 is provided from the upper surface of the reaction recess 244 toward the upper surface of the front case 236, and an upper vent hole 248 is opened on the upper surface of the front case 236. Further, a groove-like lower flow path 250 is provided downward from the lower surface of the reaction recess 244, and a lower vent hole 252 is opened on the lower surface of the front case 236. Then, as shown in FIG. 2, a rectangular parallelepiped space B is formed between the cathode current collector 214 on the cathode side and the front wall of the front case 236 by the reaction recess 244.

  Next, the middle case 240 will be described with reference to FIG. A front fixing member 226 of the oxygen reduction unit 202 is housed in the central portion 242 of the frame-shaped middle case 240.

  Next, the rear case 238 will be described with reference to FIGS. A storage recess 254 that can store the rear fixing member 224 of the oxygen reduction unit 202 is provided at the center of the front surface of the rear case 238, and the current collectors 212 and 214 of the current collectors 212 and 214 are arranged from the storage recess 254 toward the upper surface of the rear case 238. Grooves 256 and 258 from which the protruding pieces protrude are provided. An exhaust recess 260 is further provided on the rear surface of the storage recess 254, and the lower surface of the exhaust recess 260 has an inclined surface so as to approach each other and communicates with the exhaust port 262. The exhaust port 262 opens on the lower surface of the rear case 238.

  The case 204 in which the oxygen reduction unit 202 is stored is attached to the rear surface of the container storage unit 104 of the oxygen reduction chamber 100. This attachment method will be described with reference to FIG.

  At the center of the rear surface of the container storage unit 104, a cubic storage holding unit 264 projects toward the storage side. The storage case 264 stores the front case 236 of the case 204 from the rear. Therefore, the upper hole 266 and the lower hole 268 are opened at positions corresponding to the upper ventilation hole 248 and the lower ventilation hole 252 which are opened on the upper surface and the lower surface of the front case 236.

  Since the case 204 protrudes from the rear surface of the container storage unit 104, the cover 270 is covered so as to cover the protruding portion. The cover 270 is made of a synthetic resin and has a shape that covers the entire rear case 238 of the case 204. The cover 270 is provided with current collector openings 278 and 278 through which both current collectors 212 and 214 protrude. In addition, an exhaust port 280 communicating with the exhaust port 262 of the rear case 238 is opened.

(4) Water supply device 300
Next, the water supply apparatus 300 is demonstrated based on FIG. 2 and FIG.

  The water supply apparatus 300 has a water supply main body 302, and the water supply main body 302 is a horizontally long rectangular parallelepiped box. The water supply main body 302 is vertically divided by a partition wall 304 inside thereof, and an upper portion constitutes a water purification compartment 306 and a lower portion constitutes a suction section 308. A water supply pipe 152 is connected to the upper surface of the left end portion of the water supply main body 302, that is, the upper surface of the water purification section 306. The defrost water generated from the R EVA 28 of the refrigerator 10 is fed into the water supply pipe 152 via the tray 54.

  As shown in FIG. 6, the partition wall 304 is inclined downward from a portion to which the water supply pipe 152 is connected, and a water supply hole 310 leading to the suction section 308 is formed at the right end. A purified water section 312 made of an ion exchange resin is provided inside the purified water section 306. By providing this water purification unit 312, it is possible to remove the influence of the quality of defrost water supplied from the R EVA 28, and to prevent the oxygen reduction unit 115 from deteriorating. That is, the defrost water is frost adhering to the R EVA 28 and is collected in the drain pan, and therefore contains metal ions. Therefore, since there is a possibility of promoting the hydrolysis of the synthetic resin fibers constituting the water supply sheet 222, the provision of the water purification unit 312 can remove the influence of the quality of the defrost water.

  The suction section 308 has a water storage tank 314 for storing the water supplied from the water supply hole 310. Further, a drain pipe 154 is provided at the left end of the suction section 308. A partition wall 316 is provided between the drain pipe 154 and the water storage tank 314. The defrost water supplied from the water supply hole 310 is accumulated in the water storage tank 314. The water storage tank 314 is recessed at the center, and the lower part of the water supply sheet 222 of the oxygen reduction unit 202 described above is immersed, and the water supply sheet 222 sucks up the accumulated water. When the amount of water in the water storage tank 314 increases and exceeds the partition wall 316, the water is drained from the drain pipe 154 to an evaporating dish (not shown). In the water supply main body 302 which is a horizontally long rectangular parallelepiped, the suction section 308 protrudes forward from the water purification section 306, and the water supply sheet 222 is drawn from the ceiling surface protruding forward from the suction section 308.

  The water supply sheet 222 is formed of a non-woven fabric as described above, and when the lower end of the water supply sheet 222 is immersed in the water accumulated in the water storage tank 314, the water is sucked up, and the slit 211 is formed at the position of the spacer 211. The gaseous water (water vapor) is supplied to the anode 208 through the water supply opening 213. Here, the water supply sheet 222 made of this non-woven fabric forms a water film on the surface when water is sucked up, but the non-woven fabric is rough and the non-woven fabric is not covered by this water film. A portion 320 is formed. As shown in FIG. 3, the opening 320 is also formed in a portion corresponding to the position of the anode 208 of the water supply sheet 222. As this nonwoven fabric, for example, FD-K70-06R manufactured by Frontier Sangyo Co., Ltd. is used.

(5) Operation state of oxygen reduction device 200 The operation state of the oxygen reduction device 200 will be described.

  When food is stored in the oxygen-reducing chamber 100, the control plate 70 starts energizing both the current collectors 212 and 214.

  Next, as shown in FIGS. 2 and 5, the air in the oxygen reduction container 106 is supplied through the lower vent 252 of the oxygen reduction chamber 100, the downstream passage 250, the space B, and the opening 234 of the front fixing member 226. Since both the current collectors 212 and 214 are energized, oxygen reduction is performed from the inflowing air, and the oxygen reduction chamber 100 becomes the CA storage chamber. In the anode 208 and the cathode 210, the oxygen reduction reaction as shown in the following formulas (1) and (2) is performed.

Anode: 2H ₂ O → O ₂ + 4H ⁺ + 4e ⁻ (1)

Cathode ... O ₂ + 4H ⁺ + 4e ⁻ → 2H ₂ O (2)

Explaining this oxygen reduction reaction formula, water vapor from the water supply sheet 222 passes through the space A and is electrolyzed at the anode 208 to form hydrogen ions (proton H ⁺ ). The hydrogen ions move through the electrolyte membrane 116. It reaches the cathode 210 and reacts with oxygen inside the oxygen-reducing chamber 100 to generate water and consume oxygen. This reduces oxygen and allows food to be stored in CA.

  Next, as shown in FIGS. 2 and 6, the oxygen generated at the anode 208 of the oxygen reduction unit 202 is diffused and discharged from the exhaust passage 262 of the rear case 238. At this time, the discharged oxygen reaches the position of the water supply sheet 222 through the slit-shaped opening 216 of the anode current collector 212 and the water supply opening 213 of the spacer 211. Since the opening 320 is also opened in the water supply sheet 222, oxygen is not blocked by the water supply sheet 222, and oxygen is discharged from the opening 232 of the rear fixing member 224. Therefore, the discharge of oxygen does not inhibit the electrolysis at the anode 208.

(6) Effect In the refrigerator 10 of the above embodiment, the water supply sheet 222 in the oxygen reduction device 200 is made of a non-woven fabric, and when this non-woven fabric sucks up water, all parts are not covered with water, but an opening Since 320 is open, oxygen generated by electrolysis of the anode 208 can be exhausted from the opening 320, and this electrolysis reaction is not hindered.

  Further, since the water supply sheet 222 is a non-woven fabric, it is easy to suck up water from the water storage tank 314, and therefore, the electrolysis reaction of the formula (1) is likely to occur.

  Further, even if the rear fixing member 224 stores the water supply sheet 222 in the storage recess 228 and fixes the front fixing member 226 and the rear fixing member 224, no excessive pressing force is applied to the water supply sheet 222. . Therefore, the water supply sheet 222 does not deteriorate over time due to heat generation of the oxygen reduction cell.

Embodiment 2

  Next, the oxygen reduction apparatus 200 in the refrigerator 10 of Embodiment 2 is demonstrated based on FIG.

  The difference between the present embodiment and the first embodiment is a spacer 211 disposed between the anode current collector 112 and the water supply sheet 222 used in the oxygen reduction unit 202.

  As shown in FIG. 8, in the spacer 211 of this embodiment, a notch 322 for discharging oxygen is formed in the horizontal direction at the edge in the vertical direction.

  Oxygen generated from the anode 208 passes through the notch 322 of the rear fixing member 224 and is discharged to the side of the oxygen reduction unit 202. Accordingly, oxygen discharge is not blocked, and the electrolysis reaction of the formula (1) at the anode 208 is not inhibited.

Embodiment 3

  Next, the oxygen reduction apparatus 200 in the refrigerator 10 of Embodiment 3 is demonstrated based on FIG.

  If the water supply sheet 222 of the oxygen reduction device 200 deteriorates, the water absorption speed from the water storage tank 314 increases, and there is a possibility that a stable reaction cannot be performed. Therefore, in this embodiment, in order to prevent the deterioration of the water supply sheet 232, the convex portion 324 is projected forward from the portion between the slit-like openings 232 and 232 of the rear fixing member 224. Yes. The convex portion 324 is provided at a position corresponding to the position of the anode 208.

  When the rear fixing member 224 and the front fixing member 226 are screwed with screws (not shown), the convex portion 324 presses the water supply sheet 222 toward the spacer 211, and the spacer 211 causes the anode current collector 212 to move to the anode 208. Press. Therefore, the anode 208 and the anode current collector 212 are always constantly in contact with each other, the contact resistance is reduced, and deterioration of the water supply sheet 222 can be prevented.

  That is, when the rigidity of the anode current collector 212 is low, the anode 208 and the anode current collector 212 are not closely contacted with each other, and the contact resistance is increased, so that the water supply sheet 222 is rapidly deteriorated. However, when the spacer 211 is pressed, the rigidity of the anode current collector 212 is increased, and the anode current collector 212 always contacts the entire surface of the anode 208, and the contact resistance is reduced.

Example of change

  In the above embodiment, the oxygen-reducing chamber 100 is provided on the ceiling of the vegetable chamber 14, but instead, the oxygen-reducing chamber 100 may be provided in the chilled chamber 44. This is because the fats and oils contained in the meat stored in the chilled chamber 44 are prevented from being oxidized and are suitable for storing meat and the like.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 10 ... Refrigerator, 100 ... Oxygen reduction chamber, 200 ... Oxygen reduction apparatus, 202 ... Oxygen reduction unit, 206 ... Solid polymer electrolyte membrane, 208 ... Anode, 210 ... Cathode, 212 ... Anode current collector, 214 ... Cathode current collector, 222 ... Water supply sheet, 211 ... Spacer, 224 ... Rear fixing member, 226 ... Front fixing member, 300 ... Water supply equipment, 314 ... Water storage tank

Claims (7)

A polymer electrolyte membrane;
An anode provided on one side of the polymer electrolyte membrane;
A cathode provided on the other side of the polymer electrolyte membrane and leading to a reduced oxygen space;
An anode current collector for energizing the anode;
A cathode current collector for energizing the cathode;
A water supply sheet provided on the anode side;
A plate-like spacer provided between the anode current collector and the water supply sheet;
A water storage tank for supplying water to the water supply sheet;
Have
The water supply sheet has an opening that is not covered with a water film, with its lower part immersed in the water of the water storage tank,
Hypoxic device. The opening of the water supply sheet is open at a position corresponding to the polymer electrolyte membrane,
The oxygen reduction device according to claim 1. Except for the position corresponding to the polymer electrolyte membrane of the water supply sheet, the lower part of the water supply sheet is immersed in the water of the water storage tank, and is not covered with a water film and opened.
The oxygen reduction device according to claim 1 or 2. A polymer electrolyte membrane;
An anode provided on one side of the polymer electrolyte membrane;
A cathode provided on the other side of the polymer electrolyte membrane and leading to a reduced oxygen space;
An anode current collector for energizing the anode;
A cathode current collector for energizing the cathode;
A water supply sheet provided on the anode side;
A plate-like spacer provided between the anode current collector and the water supply sheet;
A water supply opening provided in the spacer and leading from the anode current collector to the water supply sheet;
A notch for oxygen discharge provided at the edge of the spacer;
A hypoxic device. The water supply sheet is a nonwoven fabric;
The oxygen reduction device according to any one of claims 1 to 4. The cathode current collector, the cathode, the polymer electrolyte membrane, the anode, the anode current collector, the spacer, a front fixing member for sandwiching the water supply sheet from the front and rear direction, and a rear fixing member,
A recess is formed in the edge by projecting the edge of the rear fixing member in a frame shape,
The water supply sheet is arranged at a position corresponding to the recess,
The oxygen reduction device according to any one of claims 1 to 5. The cathode current collector, the cathode, the polymer electrolyte membrane, the anode, the anode current collector, the spacer, a front fixing member for sandwiching the water supply sheet from the front and rear direction, and a rear fixing member,
A convex portion is provided on the front surface of the rear fixing member,
The convex portion presses the water supply sheet from behind to the spacer,
The oxygen reduction device according to any one of claims 1 to 6.

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