Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
  • F23C10/00—Fluidised bed combustion apparatus
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
  • F23C10/00—Fluidised bed combustion apparatus
  • F23C10/02—Fluidised bed combustion apparatus with means specially adapted for achieving or promoting a circulating movement of particles within the bed or for a recirculation of particles entrained from the bed
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F22—STEAM GENERATION
  • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
  • F22B31/00—Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements of dispositions of combustion apparatus
  • F22B31/0007—Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements of dispositions of combustion apparatus with combustion in a fluidized bed
  • F22B31/0084—Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements of dispositions of combustion apparatus with combustion in a fluidized bed with recirculation of separated solids or with cooling of the bed particles outside the combustion bed
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F22—STEAM GENERATION
  • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
  • F22B31/00—Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements of dispositions of combustion apparatus
  • F22B31/0007—Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements of dispositions of combustion apparatus with combustion in a fluidized bed
  • F22B31/0084—Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements of dispositions of combustion apparatus with combustion in a fluidized bed with recirculation of separated solids or with cooling of the bed particles outside the combustion bed
  • F22B31/0092—Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements of dispositions of combustion apparatus with combustion in a fluidized bed with recirculation of separated solids or with cooling of the bed particles outside the combustion bed with a fluidized heat exchange bed and a fluidized combustion bed separated by a partition, the bed particles circulating around or through that partition

Definitions

• the present invention provides combustion of various kinds of coal, low-grade coal, coal-cleaning sludge, filco-tas, etc. by a so-called swirling type fluidized bed, and at the same time, a circulating fluidized bed and a free-flowing bed.
• This is an internal circulating fluidized bed boiler that recovers heat from the heat transfer section provided in one port and downstream of the free board section.
• fluidized bed boilers there are two types of fluidized bed boilers, depending on the arrangement of the heat transfer section and the method that takes into account the burning of unburned particles protruding from the fluidized bed.
• Non-circulating fluidized bed boiler (conventional fluidized bed boiler or publishing type fluidized bed boiler ⁇ ) (2) Circulating fluidized bed boiler
• a ripening tube is arranged in a fluidized bed, and heat exchange is performed with high heat transfer efficiency by physical contact between fuel and fluid medium burning at high temperature.
• FIG. 4 shows a non-circulating flow-bed boiler, in which fluidizing air pumped from a blower (not shown) passes through a dispersion plate 72 from an air chamber 74 to be boiled.
• the fuel is ejected into 1 to form a fluidized bed 73, and the fuel, for example, granular coal, is supplied to the fluidized bed 73 and burned.
• Fig. 5 shows a circulating fluidized-bed boiler. Fluidizing air pumped from a not-shown propellant is supplied from an air chamber 104 through a dispersing plate 102 to a furnace 10. The fine-grained coal containing lime as a desulfurizing agent that is blown into the furnace and supplied to the furnace is fluidized and burned as necessary.
• the mixing speed of the fluidizing air blown through the dispersion plate 102 is higher than the terminal speed of the fluidized particles, so that the mixing of particles and gas becomes more active.
• the particles are blown up together with the gas, and a fluidized bed and a spouted bed are formed in this order from below over the entire area of the combustion furnace.
• the particles and gas undergo heat exchange in the water-cooled reactor wall 107 on the way, and then are led to the cyclone 108. After the combustion gas leaves the cyclone 108, heat is exchanged in the convection heat transfer section 109 installed in the rear flue.
• the particles collected in the cyclone 108 are returned to the combustion chamber again through the flow channel 113, and some of the particles are recovered in the flow channel 111 to control the furnace temperature. After passing through the external heat exchanger 115, it is cooled and returned to the combustion chamber again, but part of it is discharged to the outside as ash.
• the feature is that the particles circulate in the combustion chamber in this way.
• the circulating particles are mainly limestone flooded as a desulfurizing agent and the combustion ash and unburnt ash of the supplied coal.
• a swirling flow is provided inside the fluidized bed at different fluidization speeds, and the swirling flow is used to generate heat.
• an internal circulating fluidized bed boiler * that forms a circulating flow of fluidized medium between the recovery chamber and a freeboard section on the fluidized bed or a heat recovery section such as an evaporator tube downstream of the freeboard section.
• the low-temperature exhaust gas after heat recovery is guided to the cycle ⁇ , and the collected particles in the cycle port are returned to the descending moving bed of the rinsing medium in the fluidized bed, thereby reducing the boiler core. It has been found that it is possible to improve the compactness and combustion efficiency and to reduce NO x.
• the fluidized bed section is largely divided into a main combustion chamber and a heat recovery chamber, and the main combustion chamber has a large fluidization rate at the lower part-an air chamber and a small fluidization rate.
• At least two types of air chambers are provided.A combination of these different fluidization speeds provides a swirling circulation flow to the fluid medium in the main combustion chamber, and A heat recovery circulating flow of the fluid medium is formed between the heat recovery chamber and the air chamber that provides a small fluidization rate to the lower part of the heat recovery chamber and the side of the main combustion chamber opposite to the heat recovery chamber.
• the exhaust gas is guided to a cyclone, and the collected particles are returned to the downward moving bed of the main combustion chamber or the heat recovery chamber.
• the effect of returning the char to the descending moving bed is that when returning to the fluidized bed, the char is fine particles, so it is immediately scattered to the free port area.
• the residence time is almost nil, and the combustion of the character itself and the function as a low NOx catalyst cannot be sufficiently performed.However, when it is used in a descending moving bed, even fine particles remain in the bed. Because of sedimentation and diffusion, the charcoal can sufficiently reach the place where NOx is generated by burning coal and the like in the formation, which is extremely effective in reducing N ⁇ X.
• the reaction to this NQx reduction is
• the second feature is that heat transfer tubes are arranged on the freeboard part or downstream of the freeboard part on the fluidized bed, and heat is recovered mainly by convection heat transfer. It is.
• the convection heat transfer section has been installed separately from the free board section, but in order to achieve compaction, the free board section volume necessary for secondary combustion is secured. After that, it is installed at the upper part of the freeboard or at the downstream side of the freeboard part integrally with the freeboard part. This simplifies conventional boiler image dusting and charging cycles, and also reduces the temperature of the gas entering the cycle from 250 to 400. Therefore, the cyclone does not need to have a castable lining, and can be made of steel to reduce the amount of S and the size.
• the present invention relates to a swirling circulation flow of the main combustion chamber, a heat recovery circulation of the fluid medium performed between the main combustion chamber and the heat recovery chamber, and an unburned channel formed in the main combustion chamber or the heat recovery chamber.
• External circulation char-circulation
• a combined circulating fluidized-bed boiler that combines these three circulations.
• FIGS. 1, 2, and 3 are schematic views of different types of the combined circulating fluidized bed boilers of the present invention in which a heat transfer tube such as an evaporator tube is disposed above the freeboard.
• Fig. 4 is a schematic diagram of the conventional fluidized bed boiler
• Fig. 5 is a schematic diagram of the circulating fluidized bed boiler
• Fig. 6 is the amount of flowing air below the inclined partition wall and the amount of circulating fluid medium in the heat recovery chamber.
• Fig. 7 shows the relationship between the diffused air volume of the heat recovery chamber and the settling velocity of the descending moving bed
• Fig. 8 shows the general mass transfer mass velocity and the overall heat transfer coefficient
• Fig. 9 shows the diffused air volume and the overall heat transfer coefficient of the heat recovery chamber of the internal circulation type.
• Fig. 10 shows the relationship between the fluidization mass velocity and the wear rate of the heat transfer tubes.
• a heat transfer tube group such as a free board unit and an evaporator tube is provided on the downstream side of the board unit, relatively large particles are collected in the heat transfer tube group.
• a combined circulating fluidized-bed boiler constructed so that the heat flows into the left and right heat recovery chambers at both ends of the main combustion chamber.
• a dispersing plate 2 for fluidizing air introduced from a fluidizing air inlet pipe 15 by a blower 16 is provided at the inner bottom of the boiler body 1. Both sides of the boiler are higher than the center, and the bottom of the boiler body is formed to be concave.
• the mass velocity of the fluidizing air ejected from the central air chamber 13 is a velocity sufficient to form a fluidized bed of the fluid medium in the boiler body, that is, 4 to 20 Gmf, Preferably, it is within the range of 6 to 12 Gmf, but the mass velocity of the fluidizing air ejected from the air chambers 12 and 14 on both sides is smaller than the former and is generally smaller than the former.
• the mass velocity is 0 to 2 Gmf from the air chamber 12 below the heat recovery chamber 4 in which the heat transfer tubes 5 are arranged, and the area below the main combustion chamber 3. It is preferable that the gas is ejected from the air chamber 14 forming the part at a mass velocity of 0.5 to 2 Gmf.
• the mass velocity of the fluidizing air ejected from the air chamber 13 inside the main combustion chamber 3 is compared with the mass velocity of the fluidizing air ejected from the air chambers 12 and 14. Due to the size, the air and the fluid medium flow rapidly upward in the fluidized bed as a jet at the upper part of the air chamber 13, and diffuse around when leaving the fluidized bed surface. Air chambers 1 2, 1 4 Drop onto the upper surface of the fluidized bed.
• the gentle fluidized bed on both sides that is, the upper part of the air chambers 12, 14, should be used to confirm that the fluid medium has moved upward.
• the fluid medium at the bottom of the fluidized bed moves to the center, that is, to the upper part of the air chamber 13.
• a strong updraft is formed in the central part of the fluidized bed, but a gentle downward moving bed is formed in the peripheral part.
• the heat recovery chamber 4 uses this descending moving bed, but as shown in Fig. 8, as shown by the relation between the overall heat transfer coefficient of the baffling equation and the fluidized mass velocity, Without vigorous fluidization (typically 3 to 5 Gmf) as shown in the equation, as shown in Fig. 9, the fluidization mass velocity was 1 to 2 Gmf. A large overall heat transfer coefficient is obtained, and sufficient heat recovery is achieved by providing a vertical partition wall 18 inside the fluidized bed above the boundary between the air chambers 12 and 13. At the top, ie, the partition wall A ripening tube 5 was placed in the back of Fig. 18 and inside the fluidized bed of P on the wall of the ice-cooled furnace to form a ripening chamber.
• the height of the partition wall 18 is sufficient to allow the flowing medium to enter the heat recovery chamber 4 from the upper part of the air chamber 13 during operation, and the partition wall 18 and the bottom surface An opening 19 is provided to allow the fluid medium in the maturation recovery chamber 4 to return to the main fuel 3 in a simple manner in the air dispersion. Therefore, after rising violently as a jet in the main combustion chamber, the flow medium dispersed on the flow surface passes through the partition wall 18 and enters the heat recovery chamber, and the air chamber 12 The air that is blown from the air gradually descends while performing a gentle flow, and heat exchange is performed through the heat transfer tube 5 during that time.
• the amount of sedimentation and circulation of the fluid medium in the maturation recovery chamber depends on the amount of air diffused from the air chamber 12 into the heat recovery chamber, and the amount of air flow for air circulation from the air chamber 13 of the main combustion chamber. Is controlled. That is, as shown in FIG. 6, the amount Gt of the fluid medium entering the heat recovery chamber 4 increases as the amount of fluidizing air blown out from the air chamber 13 increases. Also, as shown in Fig. 7, when the amount of air diffused into the heat recovery chamber 4 is changed in the range of 0 to lGraf, the amount of the fluid medium that settles in the heat recovery chamber is almost proportional. And becomes almost constant when the diffused air volume of the heat recovery chamber is 1 Gmf or more.
• the amount of flowing medium entering the maturation recovery chamber 4 is G!
• the amount of the flowing medium that settles in the heat recovery chamber is an amount corresponding to Gi.
• the settling amount of the medium that sinks in the heat recovery chamber 4 is controlled. Is controlled.
• Fig. 10 shows the relationship between the fluidization mass velocity and the wear rate. That is, by setting the amount of diffused air blown into the heat recovery chamber to be 0 to 3 Gmf, preferably 0 to 2 Gmf, wear of the heat transfer tube is extremely reduced, and durability is improved. It is possible.
• the coal which is the fuel
• the coal is also supplied to the start of the descending moving bed in the main combustion chamber 3.
• it is possible to swirl and circulate inside the high-temperature fluidized bed to completely burn even high-fuel-ratio coal and to perform high-load combustion.
• coal types This contributes to the spread of boilers.
• the exhaust gas leaves the boiler and is directed to cycle 7.
• the particles collected by the cyclone 7 are introduced into the hopper 10 together with the coal supplied in parallel through the lower double damper 8 in the boiler shown in FIG.
• the screw feeder 11 mixes and supplies the mixture to the descending moving bed of the main combustion chamber, twists the unburned matter (chars) in the trapped particles, and reduces NOx. Etc.
• the particles collected by Cyclone 7 are transported separately up to just before the main combustion chamber without mixing with the stones beforehand, and then put into the descending moving bed of the main combustion chamber. Are also mixed in the bed by the swirling circulation.
• a confined heat transfer surface 6 is provided to recover the heat and function as an economizer and an evaporator tube.
• a constant temperature preferably 900, as necessary, cut off fireproof material etc. at the lower part of the sealing heat transfer surface 6 and the twisting chamber side of the water cooling furnace wall.
• install each heat transfer tube near the freeboard by wrapping it with heat insulating material, but do not obstruct the flow path of the scrubbing gas. It goes without saying that the pitch of the heat transfer tube should be considered.
• the provision of the heat insulating material 17 makes it possible to maintain the temperature of the lower portion of the freeboard at a high temperature.
• the air blown from the air inlet boiler 20 for the next combustion has the effect of reducing CO, etc.
• FIG. 2 shows another embodiment of the present invention. Basically, it has the same structure as the boiler shown in FIG. 1 and performs the same operation. The major difference is that the lower part of the partition wall 38 that separates the main combustion chamber 23 and the heat recovery chamber 24 prevents the upward flow of the air chamber 33 with a high fluidization velocity in the main combustion chamber. However, it is inclined so as to turn the flow toward the air chamber 34 where the fluidization speed is small, and the inclination angle is sealed horizontally and 10 degrees or less. 60 degrees, preferably 25 to 45 degrees.
• the projected length in the Eihei direction projected on the bottom of the inclined wall of the partition wall is the horizontal length L ⁇ 1/6 or 1/2, or preferably 1/4. It is formed to be half the length.
• the bottom fluidized bed of the boiler body 21 is divided into a heat recovery chamber 24 and a main combustion chamber 23 by the partition wall 38, and a fluidizing air distribution plate 2 2 is provided at the bottom of the main combustion chamber 23. Is provided.
• the fluidized air dispersion plate 22 has a lower portion at the center and a higher portion on the side opposite to the heat recovery chamber.
• two types of air chambers 33 and 34 are provided below the distribution plate 22.
• the mass velocity of the fluidizing air ejected from the central air chamber 33 is a velocity necessary for the fluidized medium in the main combustion chamber to form a fluidized bed, that is, 4 to 20 Gmf, preferably. Is in the range of 6 to 12 Gmf, but the mass velocity of the fluidizing air ejected from the air chamber 34 is smaller than the former, and is in the range of 0 to 3 Gmf.
• the fluid medium above the chamber 34 does not move up and down sharply, but forms a moving bed that is moving downward and is in a weak fluid state. This moving bed expands below, and the air chamber 33 Since it has reached the upper side, it is blown up by the jet of fluidizing air with a large mass velocity from the air chamber 33.
• the flowing medium exchanges heat via the heat transfer tube 25 while slowly descending, and then returns to the main combustion chamber from the opening 39.
• the amount of settling circulation of the fluid medium in the heat recovery chamber and the amount of heat recovered are controlled by the amount of diffused air blown into the heat recovery chamber, as in the embodiment shown in FIG. Boiler shown in Fig. 2 In the case of (1), it is controlled by the amount of air blown from the air diffuser 32, but its mass velocity is in the range of 0 to 3 Gmf, preferably in the range of 0 to 2 Gmf.
• the coal which is the fuel, is swirled and circulated in the fluidized bed of the main combustion chamber by being supplied to the upper part of the air chamber 34, which is the descending moving bed in the main combustion chamber 23, and very circulated.
• the particles collected by the cyclone 27 are not shown, but unlike the flooding equipment shown in Fig. 2, they may be supplied separately from the coal, or they may be supplied separately. Instead of a clean feeder, pneumatic transportation is also possible.
• a convection heat transfer surface 26 is provided at the top of the freeboard to recover heat, but the combustion temperature on the freeboard is preferably set at a certain temperature or 90 ° C.
• heat insulation materials 37 such as refractory materials are installed below the convection heat transfer surface 26 and the combustion chamber side of the ice-cooled furnace wall as necessary, and also for secondary combustion. Providing an air inlet 40 is effective in reducing C 0
• FIG. 3 shows yet another embodiment.
• the maturation recovery chamber of the embodiment shown in Fig. 2 is integrated in a symmetrical position facing each other.
• the air chamber 53 with a low mass velocity of the blown air is located at the center, and the air chambers with a high mass velocity are 52 and 54.
• the flow of the fluid medium caused by the air blown out of the air chambers 53 and 54 is reversed by the inclined partition walls 58 and 58 ', and falls to the center, and forms a downward moving layer and is located above the air chamber 53. And then split right and left and blow up again. Therefore, there are two nominal swirling flows in the fluidized bed of the main combustion chamber.
• Coal and particles collected in the cycle port are supplied to the central descent bed.
• Fig. 3 shows an example in which the particles collected at the cycle inlet and the coal are mixed and supplied by the screw feeder 51, but they are not shown but may be supplied separately. Alternatively, pneumatic transportation is also possible.
• the 'settling and circulating amount' of the fluid medium in the heat recovery chamber is controlled by the amount of diffused air introduced from the diffusers 6Q, 60 'as in the device shown in FIG.
• a convection heat transfer surface 46 is provided at the top of the freeboard to recover heat, but the combustion temperature at the freeport is maintained at a constant temperature, preferably 90 Gt.
• heat insulating material 57 such as refractory material is attached to the lower part of the heat transfer surface 46 and the combustion chamber side of the water-cooled reactor wall, and air is injected for secondary combustion as necessary. Providing the mouth 61 is effective in reducing C0 and the like.
• heat recovery from the exhaust gas is performed by a heat transfer tube group provided integrally with the free board portion on the downstream side of the free board portion.
• FIG. 11 shows an embodiment of the present invention in which heat is recovered from exhaust gas by a heat transfer tube group provided integrally with the free board portion on the downstream side of the free board portion.
• FIG. 1 shows a longitudinal sectional view of a combined circulating fluidized bed boiler
• FIG. 12 shows a sectional view taken along line AA of FIG.
• reference numeral 201 denotes the main body of the coil
• 2Q2 denotes a nozzle for dispersing air for fluidization
• 203 denotes a main combustion chamber
• 204 and 204 denotes a main combustion chamber
• Is a heat recovery chamber, 205 and 205 'are heat transfer tubes, 2007 is a cyclone, 208 is a rotor valve, 2009 is a fuel supply tube, and 210 is a fuel supply tube.
• Hopper 211 is screw feeder for feeding twisting material
• 212, 213, and 214 are air chambers, 218, 218 'are partition walls , 219 and 219 'are openings at the bottom of the heat recovery chamber
• 220 is a secondary air inlet pipe
• 229 is an exhaust gas outlet
• 230 is a steam drum
• 231 is water.
• 2 3 2 is a convection heat transfer chamber
• 2 3 3, 2 3 4 and 2 3 5 are the partition walls in the convection heat transfer chamber
• 2 3 6 is the evaporating pipe
• 2 3 7 is the water pipe wall
• 2 3 8 is the bottom of the convection heat transfer chamber
• 2 3 9 is the screw A compressor
• 240 is the exhaust pipe of the high-temperature heat transfer chamber
• 242, 242 ', 243, 243' are of a different type from the air diffuser shown in Figs. 1 shows an air diffuser.
• a heat transfer tube group for recovering heat from exhaust gas is not provided on the free board part, but is integrated with the free board part downstream of the free board part. It differs from the boiler shown in Fig. 3 in that it is provided in the convection heat transfer section provided in Fig. 3.
• the exhaust gas discharged from the exhaust gas outlet 222 of the free board part is a group of evaporating pipes provided between the steam drum 330 and the water drum 230.
• the ice and heat in the evaporative tube group are introduced into the convection heat transfer chamber 2 3 2 having the After being exchanged and cooled at 25 Q to 400, it is guided to cyclone 207 via exhaust pipe 240, and fine particles including char in the cyclone. After being collected, it is released into the atmosphere.
• the fine particles, including the chars collected in the cyclone pass through the mouth-tally valve 208, then the inlet 209, the phono.
• the fuel is returned from the same inlet as the fuel such as coal supplied to the boiler via the 210 and the skew feeder 211 just above the descending moving layer of the main combustion chamber 203. It is.
• the particles including the fluid medium having a relatively large particle size, the desulfurizing agent, and the channel separated in the convective heat transfer section 232 are collected at the V-shaped bottom below the convective heat transfer section.
• the screw conveyor 239 returns the main combustion chamber 203 to a position just above the descending moving layer opposite to the fuel supply side.
• Fig. 13 is a cross-sectional view corresponding to Fig. 12, and reference numerals 238 'and 239' also indicate the V-shaped bottom of the convection heat transfer section and the scutar Yukonya.
• two V-shaped bottoms 238 and 238 '(W-shaped bottom) are provided below the convection heat transfer chamber.
• a screw conveyor that collects relatively large channels collected at the V-shaped bottoms 238 and 238 '. 9 'at the point where it returns to the position just above the descending moving layers 204, 204' of the fluid medium in the heat recovery chambers provided on both sides of the combustion chamber, as shown in Figs. 11 and 12. It is different from La.
• FIG. 14 shows still another embodiment of the present invention.
• reference numeral 241 indicates a conduit and other reference numerals.
• the symbols have the same meaning as the symbols in FIG.
• the convective heat transfer part 23.2 To the screw feeder 2 39 at the lower part of the main combustion chamber, along with particles containing relatively large channels trapped in the convection heat transfer section. It differs from the embodiment shown in FIG. 11 only in that it is returned to the upper part.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Fluidized-Bed Combustion And Resonant Combustion (AREA)
• Invalid Beds And Related Equipment (AREA)
• Laminated Bodies (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=16667285

Family Applications (1)

Country Status (9)

Cited By (2)

Families Citing this family (12)

Citations (3)

Family Cites Families (6)

• 1989
  • 1989-08-30 AT AT89909857T patent/ATE131271T1/de not_active IP Right Cessation
  • 1989-08-30 WO PCT/JP1989/000883 patent/WO1990002293A1/ja active IP Right Grant
  • 1989-08-30 EP EP89909857A patent/EP0431163B1/en not_active Expired - Lifetime
  • 1989-08-30 AU AU41998/89A patent/AU4199889A/en not_active Abandoned
  • 1989-08-30 DE DE68925033T patent/DE68925033T2/de not_active Expired - Fee Related
  • 1989-08-31 CN CN89107888A patent/CN1017469B/zh not_active Expired
  • 1989-08-31 CA CA000610057A patent/CA1332685C/en not_active Expired - Fee Related
  • 1989-11-30 MY MYPI89001666A patent/MY104683A/en unknown
  • 1989-12-29 KR KR1019890702496A patent/KR100229691B1/ko not_active IP Right Cessation

Patent Citations (3)

Also Published As

Similar Documents

Legal Events