Honeycomb ceramic continuous firing kiln

Abstract

The application relates to the field of roller kiln equipment, in particular to a honeycomb ceramic continuous firing kiln which comprises a kiln body, one side of the kiln body is provided with an input port, the other side of the kiln body is provided with an output port, the inside of the kiln body is sequentially separated into a preheating bin, a firing bin and a cooling bin through heat insulation plates from the input port to the output port, heating combustion heads and gas circulating fans are installed in the inside of the firing bin of the kiln body, a fixing frame is installed in the middle of the kiln body, uniformly-distributed guide rollers are rotationally connected to the middle of the fixing frame, necked sections are arranged in the middle of the guide rollers, anti-skid rings are fixedly connected to one side of the middle of the periphery of the necked sections, through holes are arranged on the two sides of the periphery of the guide rollers, the application can avoid long-time unidirectional stress, fundamentally reduces the deformation risk of the guide rollers, significantly prolongs the service life of the guide rollers and the whole kiln, reduces the equipment maintenance cost and shutdown loss, and solves the problem that the guide rollers of the traditional roller kiln are prone to deformation.

Description

Technical Field

[0001] This invention relates to the field of roller kiln equipment, and more particularly to a continuous firing kiln for honeycomb ceramics. Background Technology

[0002] In the production of honeycomb ceramics, continuous firing kilns are the core equipment for sintering and shaping materials. However, traditional equipment has many prominent problems in practical applications. Traditional roller kilns require guide rollers to remain stationary for extended periods to support the material during firing, resulting in uneven heating and concentrated unidirectional stress. This makes the guide rollers prone to deformation and damage, shortening the equipment's lifespan and affecting material transport stability due to decreased guide roller precision. Furthermore, heat shielding zones easily form at the material-pallet contact points, hindering hot airflow penetration. Combined with uneven temperature distribution within the kiln, this leads to significant differences in heating between the upper and lower parts and the inner and outer sides of the honeycomb ceramics, often resulting in incomplete firing, uneven finished product strength, and cracking, leading to a high defect rate. In addition, the inability to dynamically adjust the material's contact with the heat source further exacerbates inconsistencies in firing results within the same batch, severely impacting production efficiency and product market competitiveness. Therefore, there is an urgent need for a continuous firing kiln for honeycomb ceramics that can solve problems such as guide roller deformation, uneven material heating, and poor product consistency to meet the high demands of industrial production for equipment stability and product quality. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of the prior art by proposing a continuous firing kiln for honeycomb ceramics.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a continuous firing kiln for honeycomb ceramics, comprising a kiln body, an inlet on one side of the kiln body, and an outlet on the other side of the kiln body. Inside the kiln body, from the inlet to the outlet, a preheating chamber, a firing chamber, and a cooling chamber are sequentially separated by a heat insulation plate. A heating burner and a gas circulation fan are installed inside the firing chamber. A fixed frame is installed in the middle of the kiln body, and uniformly distributed guide rollers are rotatably connected to the middle of the fixed frame. Each guide roller has a necked section in its middle, and an anti-slip ring is fixedly connected to one side of the outer periphery of each necked section. Uniformly distributed openings are provided on both sides of the outer periphery of each guide roller. The roller supports multiple trays, each tray including a base. A top plate is rotatably connected to the top of each base. The upper part of the inner side wall of each top plate is provided with toothed grooves. Both the top plate and the base have evenly distributed openings. A rotating seat is rotatably connected to the middle of each base. The bottom of the rotating seat and the outer periphery of the anti-slip ring are provided with anti-slip fine teeth. The anti-slip fine teeth of the rotating seat and the anti-slip fine teeth of the anti-slip ring mesh with each other. A rotating column is fixedly connected to the top of each rotating seat. An impeller is fixedly connected to the outer periphery of each rotating column. A toothed ring is fixedly connected to the outer periphery of each impeller. A transmission gear is meshed on one side of the outer periphery of the toothed ring. The end of the transmission gear away from the toothed ring is meshed with the toothed groove.

[0005] Preferably, an annular groove is formed in the middle of the outer periphery of the top plate, and a rotating ring is rotatably connected to the inner side of the annular groove.

[0006] Preferably, guide grooves are provided in the middle of both sides of the fixed frame, and limit blocks are fixedly connected to both sides of the outer periphery of the chassis, and the limit blocks are slidably connected to the inner side of the guide grooves.

[0007] Preferably, each of the transmission gears is fixedly connected to a rotating shaft in the middle, and each rotating shaft is fixedly connected to a fixing block at the bottom, with the fixing blocks fixedly connected to one side inside the chassis.

[0008] Preferably, an electric push plate is installed on the inner side of the end of the fixed frame near the output port, and the electric push plate is located on the side of the outermost guide roller.

[0009] Preferably, a top chamber is installed on the top of the kiln body, and a gas circulation pump is installed inside the top chamber. The top plate is used to support the honeycomb ceramic blank.

[0010] Preferably, a fixing compartment is provided on both sides of the fixing frame, and a reduction motor is installed at the end of the outermost guide roller, and the reduction motor is installed inside the fixing compartment.

[0011] Preferably, one side of the bottom of the rotating seat is in contact with the anti-slip ring, and the rotating column, impeller and toothed ring are all arranged on the inner side between the top plate and the bottom plate.

[0012] Preferably, a control panel is installed on one side of the kiln body, and the control panel is used to control other electrical control equipment.

[0013] Preferably, the guide rollers are all connected to the transmission chain via transmission sprockets, and the transmission sprockets and transmission chains are all located inside the fixed frame.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] In traditional roller kilns, the guide rollers must remain stationary for extended periods to support the material, leading to uneven heating and concentrated unidirectional stress, making them prone to deformation and damage, thus affecting the stability of continuous equipment operation. This invention addresses this problem by using an electric pusher plate to intercept the guide rollers, allowing the trays and honeycomb ceramic blanks to remain stably in the kiln for prolonged firing while the guide rollers continue to rotate. The continuous rotation of the guide rollers not only ensures uniform heating but also avoids prolonged unidirectional stress, fundamentally reducing the risk of guide roller deformation, significantly extending the service life of the guide rollers and the kiln as a whole, reducing equipment maintenance costs and downtime losses, solving the problem of easily deformed guide rollers in traditional roller kilns, and extending the service life of the equipment.

[0016] In traditional firing equipment, the contact area between honeycomb ceramics and the tray easily forms a "shading zone," making it difficult for heat to penetrate. This results in significant differences in heating between the upper and lower parts and the inner and outer sides of the material, easily leading to quality problems such as insufficient firing, uneven strength of the finished product, and cracking. This invention utilizes the rotation of guide rollers to drive the rotating seat, rotating column, and impeller to operate synchronously. The rotation of the impeller drives the hot airflow in the kiln to flow upward through the openings of the bottom and top plates. This achieves reverse heating of the bottom of the tray and allows the hot airflow to penetrate the internal channels of the honeycomb ceramics, forming a comprehensive and dead-angle-free heating environment. At the same time, the circulating flow of hot airflow also optimizes the temperature field distribution in the kiln, avoids excessive local temperature differences, ensures uniform heating of all parts of the honeycomb ceramics, significantly improves the density, strength, and dimensional accuracy of the finished product, and reduces the defect rate.

[0017] To address the issue of inconsistent firing results and poor product uniformity caused by temperature differences between the sides and front and back areas of traditional kilns due to factors such as the layout of heating elements and airflow paths, this invention utilizes a gear ring, transmission gears, and tooth grooves to drive the top plate and honeycomb ceramics to rotate synchronously. This allows the material to continuously switch its contact position with the hot airflow in different areas of the kiln during firing. Even if there are slight temperature distributions within the kiln, the dynamic rotation of the material can achieve "uniform temperature contact." Furthermore, the rotating ring design on the outer periphery of the top plate solves the problem of rotational interference when adjacent trays are in contact, ensuring smooth rotation of the top plate and further guaranteeing the consistency of firing results for the same batch and even different batches of material, thereby improving product quality stability and pass rate. Attached Figure Description

[0018] Figure 1 This is a frontal three-dimensional structural diagram of a continuous honeycomb ceramic firing kiln according to the present invention;

[0019] Figure 2 This is a partial structural diagram of the opening of a continuous firing kiln for honeycomb ceramics according to the present invention.

[0020] Figure 3 This is a partial structural diagram of the rotating seat of a continuous firing kiln for honeycomb ceramics according to the present invention.

[0021] Figure 4 This is a partial structural diagram of the impeller of a continuous firing kiln for honeycomb ceramics according to the present invention.

[0022] Figure 5 This is a partial structural diagram of the toothed groove of a continuous firing kiln for honeycomb ceramics according to the present invention.

[0023] Figure 6 This is a partial structural schematic diagram of the transmission gear of a continuous firing kiln for honeycomb ceramics according to the present invention.

[0024] Figure 7 This is a partial structural diagram of the electric pusher plate of a continuous honeycomb ceramic firing kiln according to the present invention.

[0025] 101. Kiln body; 102. Control panel; 103. Top hopper; 104. Opening; 105. Honeycomb ceramic blank; 106. Fixed hopper; 107. Fixed frame; 108. Through-hole; 109. Guide roller; 110. Guide groove; 111. Neck section; 112. Rotating ring; 113. Base plate; 114. Anti-slip ring; 115. Top plate; 116. Limiting block; 117. Rotating seat; 118. Rotating column; 119. Impeller; 120. Gear ring; 121. Transmission gear; 122. Rotating shaft; 123. Fixed block; 124. Ring groove; 125. Gear groove; 126. Electric push plate. Detailed Implementation

[0026] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0027] like Figures 1-7The honeycomb ceramic continuous firing kiln shown includes a kiln body 101. An inlet is located on one side of the kiln body 101, and an outlet is located on the other side. Inside the kiln body 101, from the inlet to the outlet, a preheating chamber, a firing chamber, and a cooling chamber are sequentially separated by heat insulation plates. A heating burner and a gas circulation fan are installed inside the firing chamber of the kiln body 101. The specific layout of the heating burner and the gas circulation fan is existing technology and will not be described in detail here. A fixed frame 107 is installed in the middle of the kiln body 101, and evenly distributed guide rollers 10 are rotatably connected to the middle of the fixed frame 107. 9. A top chamber 103 is installed on the top of the kiln body 101. A gas circulation pump is installed inside the top chamber 103. The top plate 115 is used to support the honeycomb ceramic blank 105. Fixed chambers 106 are set on both sides of the fixed frame 107. A reduction motor is installed at the end of the outermost guide roller 109. The reduction motor is installed inside the fixed chamber 106. The guide rollers 109 are all connected to the transmission chain through transmission sprockets. The transmission sprockets and transmission chain are all set inside the fixed frame 107. A control panel 102 is installed on one side of the kiln body 101. The control panel 102 is used to control the other electrical control equipment.

[0028] Furthermore, in specific implementation, the honeycomb ceramic blank 105 can be sintered using a continuous roller kiln. Specifically, an empty firing tray is first placed on top of the guide roller 109 via the guide groove 110 and the limiting block 116. The honeycomb ceramic blank 105 to be fired is then placed on top of the top plate 115 according to the specifications. Next, the servo motor inside the fixed chamber 106 is started, thereby driving the connected guide roller 109 to rotate. The transmission sprockets and chains between the guide rollers 109 drive the other guide rollers 109 to rotate synchronously. The guide rollers 109 then drive the top plate 113 to move, allowing the tray and the honeycomb ceramic blank 105 to be moved into the kiln body 101. The ceramic blank 105 first enters the preheating chamber to preheat it. Then, as the firing process progresses, the guide roller 109 carries the ceramic blank 105 further into the firing chamber. The heating burner inside the firing chamber heats the gas inside. The gas circulation fan inside the firing chamber circulates the heated gas, ensuring even heat distribution. The gas circulation pump inside the top chamber 103 directs some of the hot gas into the preheating and cooling chambers on both sides, achieving preheating and gradual cooling. This prevents excessive instantaneous temperature differences when the ceramic blank 105 enters and exits the firing chamber, which could cause cracks and affect the quality of the finished product.

[0029] The fixed frame 107 has guide grooves 110 in the middle of both sides, and limit blocks 116 are fixedly connected to both sides of the outer periphery of the chassis 113. The limit blocks 116 are slidably connected to the inner side of the guide grooves 110. An electric push plate 126 is installed on the inner side of the fixed frame 107 near the output port. The electric push plate 126 is located on the side of the outermost guide roller 109. The bottom side of the rotating seat 117 is in contact with the anti-slip ring 114. The rotating column 118, impeller 119 and toothed ring 120 are all located on the inner side between the top plate 115 and the chassis 113.

[0030] Furthermore, in specific implementation, the electric push plate 126 at the end of the fixed frame 107 can be activated, causing the top telescopic section of the electric push plate 126 to rise, thereby blocking the tray and allowing the tray and the honeycomb ceramic blank 105 to remain inside the kiln body 101 for long-term firing. The interception by the electric push plate 126 ensures that the upper tray remains stable while the guide roller 109 continues to rotate, avoiding the deformation that easily occurs when the guide roller is heated and subjected to unidirectional force for a long time without moving during traditional roller kiln firing. By keeping the guide roller 109 rotating during firing, the guide roller 109 can be heated evenly while avoiding long-term unidirectional force, which is beneficial for the long-term use of the guide roller 109.

[0031] Each guide roller 109 has a necked section 111 in the middle. An anti-slip ring 114 is fixedly connected to one side of the middle of the outer periphery of the necked section 111. The guide roller 109 has evenly distributed openings 108 on both sides of its outer periphery. The guide roller 109 supports multiple trays on its upper side. Each tray includes a base 113. A top plate 115 is rotatably connected to the top of the base 113. The upper part of the inner side wall of the top plate 115 is provided with toothed grooves 125. The top plate 115 and the base 113 are both penetrated by evenly distributed openings 104. A rotating seat 117 is rotatably connected to the middle of the base 113. The bottom of the rotating seat 117 and the outer periphery of the anti-slip ring 114 are provided with meshable anti-slip teeth. The anti-slip teeth of the rotating seat 117 and the anti-slip teeth of the anti-slip ring 114 mesh with each other. A rotating column 118 is fixedly connected to the top of the rotating seat 117. An impeller 119 is fixedly connected to the outer periphery of the rotating column 118.

[0032] Furthermore, in specific implementation, during firing, the anti-slip ring 114 on the necked section 111 will contact the rotating seat 117 at the bottom of the base 113. The rotation of the guide roller 109 can drive the rotating column 118 to rotate by the meshing and friction of the fine teeth between the anti-slip ring 114 and the rotating seat 117. The rotating column 118 can drive the impeller 119 and the toothed ring 120 to rotate synchronously. The rotation of the impeller 119 can drive the airflow below to rise, so that the surrounding hot airflow will rise through the opening 104 and contact the honeycomb ceramic blank 105 on the top plate 115, realizing synchronous heating of the bottom of the top plate 115 and the honeycomb ceramic blank 105. At the same time, the rising hot airflow will pass through the honeycomb channels inside the honeycomb ceramic blank 105, realizing the overall heating of the honeycomb ceramic blank 105, so that the honeycomb ceramic blank 105 can be heated more evenly, avoiding the slow heating of the part of the honeycomb ceramic blank 105 in contact with the top plate 115, which would affect the quality of the fired product.

[0033] Among them, a gear ring 120 is fixedly connected to the outer periphery of the impeller 119, and a transmission gear 121 is meshed with one side of the outer periphery of the gear ring 120. The end of the transmission gear 121 away from the gear ring 120 is meshed with the tooth groove 125. A rotating shaft 122 is fixedly connected to the middle of the transmission gear 121. A fixing block 123 is fixedly connected to the bottom of the rotating shaft 122. The fixing block 123 is fixedly connected to one side of the chassis 113. A ring groove 124 is opened in the middle of the outer periphery of the top plate 115. A rotating ring 112 is rotatably connected to the inner side of the ring groove 124.

[0034] Furthermore, in specific implementation, when the impeller 119 rotates, it drives the transmission gear 121 meshing with it to rotate synchronously through the gear ring 120. The transmission gear 121 can drive the top plate 115 to rotate synchronously through the meshing tooth groove 125, thereby driving the honeycomb ceramic blank 105 on the top plate 115 to rotate synchronously. This allows the honeycomb ceramic blank 105 to continuously contact the heating gas in different parts, avoiding uneven heat distribution on both sides of the firing chamber from going unnoticed and affecting the firing effect. During this process, the rotating ring 112 on the outside of the top plate 115 can ensure that the top plate 115 can still rotate smoothly when adjacent top plates 115 are in contact, which is beneficial for practical use.

[0035] Working principle:

[0036] In practical use, the honeycomb ceramic blank 105 can be sintered using a continuous roller kiln. Specifically, an empty firing tray is first placed on top of the guide roller 109 via the guide groove 110 and the limiting block 116. The honeycomb ceramic blank 105 to be fired is then placed on top of the top plate 115 according to the specifications. Next, the servo motor inside the fixed chamber 106 is started, driving the connected guide roller 109 to rotate. The transmission sprockets and chains between the guide rollers 109 drive the other guide rollers 109 to rotate synchronously. The guide rollers 109 then move the top plate 113, allowing the tray and the honeycomb ceramic blank 105 to be moved into the kiln body 101. The honeycomb ceramic blank 105 will then... The honeycomb ceramic blank 105 is preheated by entering the preheating chamber. As firing progresses, the guide rollers 109 further guide the blank into the firing chamber. The heating burners inside the firing chamber heat the gas, which is then circulated by a gas circulation fan to ensure even heat distribution. A gas circulation pump inside the top chamber 103 directs some of the hot gas to the preheating and cooling chambers on either side, achieving both preheating and gradual cooling. This prevents excessive temperature differences when the honeycomb ceramic blank 105 enters and exits the firing chamber, which could cause cracks and affect the quality of the finished product. In practical use, users can start... The electric push plate 126 at the end of the movable fixed frame 107 raises the top telescopic section of the electric push plate 126, thereby blocking the tray and allowing the tray and honeycomb ceramic blank 105 to remain inside the kiln body 101 for long-term firing. The blocking action of the electric push plate 126 ensures that the upper tray remains stable while the guide roller 109 continues to rotate, avoiding the deformation that easily occurs when the guide roller is heated and subjected to unidirectional force for a long time without movement in traditional roller kilns. By keeping the guide roller 109 rotating during firing, it can be heated evenly while avoiding prolonged unidirectional force, which is beneficial for the long-term use of the guide roller 109. During firing, the anti-slip ring 114 on the necking section 111 will contact the bottom of the base 113. The rotating seat 117 is in contact with the guide roller 109. The rotation of the guide roller 109, through the meshing and friction of the fine teeth between the anti-slip ring 114 and the rotating seat 117, drives the rotating column 118 to rotate. The rotating column 118 drives the impeller 119 and the toothed ring 120 to rotate synchronously. The rotation of the impeller 119 drives the airflow below to rise, so that the surrounding hot airflow rises through the opening 104 and comes into contact with the honeycomb ceramic blank 105 on the top plate 115, achieving synchronous heating of the top plate 115 and the bottom of the honeycomb ceramic blank 105. At the same time, the rising hot airflow passes through the honeycomb channels inside the honeycomb ceramic blank 105, achieving comprehensive heating of the honeycomb ceramic blank 105, making the honeycomb ceramic blank 105 more evenly heated.To prevent the honeycomb ceramic blank 105 from heating too slowly at the contact point with the top plate 115, thus affecting the quality of the fired product, the impeller 119 rotates, driving the transmission gear 121 meshing with it to rotate synchronously via the gear ring 120. The transmission gear 121, through its meshing tooth groove 125, drives the top plate 115 to rotate synchronously, thereby driving the honeycomb ceramic blank 105 on top of the top plate 115 to rotate synchronously. This ensures that the honeycomb ceramic blank 105 continuously contacts the heating gas at different locations, preventing uneven heat distribution on both sides of the firing chamber from going unnoticed and affecting the firing effect. During this process, the rotating ring 112 on the outer side of the top plate 115 ensures that the top plate 115 can still rotate smoothly even when adjacent top plates 115 are in contact, which is beneficial for practical use.

[0037] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A continuous firing kiln for honeycomb ceramics, comprising a kiln body (101), characterized in that: The kiln body (101) has an inlet on one side and an outlet on the other side. Inside the kiln body (101), from the inlet to the outlet, there are preheating chambers, firing chambers, and cooling chambers separated by heat insulation plates. The firing chamber inside the kiln body (101) is equipped with a heating burner and a gas circulation fan. A fixed frame (107) is installed in the middle of the kiln body (101). The fixed frame (107) is rotatably connected to a uniformly distributed guide roller (109) in the middle. Each guide roller (109) has a necked section (111) in the middle. An anti-slip ring (114) is fixedly connected to one side of the outer circumference of each necked section (111). Both sides of the outer circumference of each guide roller (109) have uniformly distributed openings (108). Multiple trays are supported on the upper side of each guide roller (109). Each tray includes a base plate (113). The top of each base plate (113) is rotatably connected to a top plate. The top plate (115) has toothed grooves (125) on the upper part of its inner sidewall. Both the top plate (115) and the bottom plate (113) have evenly distributed openings (104) through them. The bottom plate (113) has a rotating seat (117) through it and rotatably connected to it. The bottom of the rotating seat (117) and the outer periphery of the anti-slip ring (114) are provided with anti-slip fine teeth. The anti-slip fine teeth of the rotating seat (117) and the anti-slip ring (114) are connected to each other. The anti-slip fine teeth mesh with each other. The top of the rotating seat (117) is fixedly connected to a rotating column (118). The outer periphery of the rotating column (118) is fixedly connected to an impeller (119). The outer periphery of the impeller (119) is fixedly connected to a toothed ring (120). The outer side of the toothed ring (120) is meshed with a transmission gear (121). The end of the transmission gear (121) away from the toothed ring (120) is meshed with a tooth groove (125).

2. The continuous firing kiln for honeycomb ceramics according to claim 1, characterized in that: The top plate (115) has an annular groove (124) in the middle of its outer periphery, and a rotating ring (112) is rotatably connected to the inner side of the annular groove (124).

3. The continuous firing kiln for honeycomb ceramics according to claim 1, characterized in that: The fixing frame (107) has guide grooves (110) in the middle of both sides, and the chassis (113) has limit blocks (116) fixedly connected to both sides of the outer periphery. The limit blocks (116) are slidably connected to the inside of the guide grooves (110).

4. The continuous firing kiln for honeycomb ceramics according to claim 1, characterized in that: Each of the transmission gears (121) is fixedly connected to a rotating shaft (122) in the middle, and each of the rotating shafts (122) is fixedly connected to a fixing block (123) at the bottom, and each of the fixing blocks (123) is fixedly connected to one side of the chassis (113).

5. A continuous firing kiln for honeycomb ceramics according to claim 1, characterized in that: An electric push plate (126) is installed on the inner side of the end of the fixed frame (107) near the output port. The electric push plate (126) is located on the side of the outermost guide roller (109).

6. The continuous firing kiln for honeycomb ceramics according to claim 1, characterized in that: The top of the kiln body (101) is equipped with a top chamber (103), and a gas circulation pump is installed inside the top chamber (103). The top plate (115) is used to support the honeycomb ceramic blank (105).

7. A continuous firing kiln for honeycomb ceramics according to claim 1, characterized in that: The fixed frame (107) has fixed compartments (106) on both sides, and a reduction motor is installed at the end of the guide roller (109) at the outermost part. The reduction motor is installed inside the fixed compartment (106).

8. A continuous firing kiln for honeycomb ceramics according to claim 1, characterized in that: The bottom side of the rotating seat (117) is in contact with the anti-slip ring (114), and the rotating column (118), impeller (119) and toothed ring (120) are all located on the inner side between the top plate (115) and the bottom plate (113).

9. A continuous firing kiln for honeycomb ceramics according to claim 1, characterized in that: A control panel (102) is installed on one side of the kiln body (101), and the control panel (102) is used to control the other electrical control equipment.

10. A continuous firing kiln for honeycomb ceramics according to claim 1, characterized in that: The guide rollers (109) are all connected to the transmission chain via transmission sprockets, and the transmission sprockets and transmission chains are all located inside the fixed frame (107).

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