Fabrication of immersion tube with permanent structure for cement rotary kilns

Abstract

The Preheater tower is the highest structure of the cement plant with a height of more than 110 meters or more and five cyclones have been designed and installed on its floors, the function of cyclones is to separate dust particles from the hot air exiting the kiln, the separation process in cyclones occurs in the immersion tube device based on gravity and fluid flow forces. In all of the existing designs in Iran and around the world, the immersion tube with holder tabs designs are used, and the claimed invention can be easily replaced in all cyclones number 1 to 5 in the pre-heater building. The main function of the immersion tube is to separate dust from the flow of hot gases exiting the kiln.

Description

DescriptionTitle of Invention : Fabrication of immersion tube with permanent structure for cement rotary kilnsTechnical Field

[0001] The technical field of this invention relates to the immersion tubes for rotary kilns of cement plants.Background Art

[0002] In fact, the most important issues of cement plants since old times are related to problems and obstacles and major weaknesses of olden designs of immersion tube with holder edges and tabs such as deformation, melting and collapse as a result of proximity with thermochemical and thermal shocks at high temperature, which leads to burning out and opening of the holder tabs of the segments that are connected to each other by brick wall arrangement or matrix arrangement from inside of each other and the falling of all the stepped rows of that are locked together by the bell and spigot tabs and by falling a row, at the top of the pyramid peak, all the segments of the lower rows are fallen in a pyramidal fashion and entered the path of transferring hot feed materials into the rotary kiln of cement plants and finally blocking the passage of load and long-term weekly and monthly interruptions and imposing frequent interruption during one year of operation to the cement kiln and lead to burns and injuries to the workers of the operation:

[0003] B-1 ) Problems and obstacles of immersion tube old designs

[0004] The problems and obstacles of the immersion tube old designs lead to the following results in cement kilns: 1 -imposed and frequent interruptions, 2-lost production of cement kilns, 3-decrease in profitability, 4-loss of national capital, 5- higher electric energy consumption, 6-higher fossil fuel consumption, 7- environment and natural resource pollution, 8-higher utilization of refractory cast steel parts, 9-increased maintenance and repair costs, safety risks, burns, health threats and the death of production workers.

[0005] B-2) Weakness in the structure of immersion tube old designs

[0006] Weakness in the structure of immersion tube old designs is attributed to the following factors: 1- weakness in transformation and deformation of holder edges and tabs 2- weakness in transformation and deformation of segment plates 3- weakness in transformation, corrosion, and burn of segment plates 4- weakness in collapse pyramid of segment plates

[0007] 1 - Weakness in transformation and deformation of holders' edges and tabs

[0008] Structurally, the weakness in the holder edges and tabs in the segment of the immersion tubes old designs in the vicinity of heat and high temperature and the exertion of the total weight of the bottom plates to the tabs of the upper rows lead to the transformation and deformation of the holder edges and tabs and their removal from each other and the collapse of the immersion tube parts.

[0009] 2- Weakness in transformation and deformation of segment plates

[0010] Following a period of less than a year and several months, the segment plates of the immersion old designs tube are severely deformed due to exposure to thermal shocks at a high temperature of 900 to 1100 C and thermochemical shocks and the cylindrical cross-section of the immersion tube takes an oval shape, and the holder edges and tabs come out of each other and the parts of the immersion tube collapse instantly and block the path of the load entering the kiln and lead to long-term interruptions of the kiln.

[0011] 3- Weakness in transformation, corrosion, and burn of segment plates

[0012] In the immersion tube old design, the weakness of the materials 1 .4823 and 1 .4837 causes weakness in the structure and physical and chemical properties and leads to deformation and burn, severe chemical corrosion, and exposure to annoying alkaline cycle exacerbates the rapid disintegration of immersion tube parts:

[0013] 4- Weakness in the collapse pyramid of segment plates

[0014] In immersion tube old designs, the segments are locked in brick wall arrangement or matrix arrangement in stepped rows by bell and spigot tabs, therefore, when one of them falls, all the segments of the lower rows fall in the form of a pyramid, and enters the path of the incoming materials, resulting in frequent interruptions of the kiln and non-continuity of production.Technical Problem

[0015] The motivation behind this invention relates to many issues and problems that result in frequent interruption of rotary kilns in cement plants with a daily production capacity of 3500 to 5000 tons per day. There are some issues including burning out, deformation, and collapsing parts of the old designs of immersion tubes with holder edges and tabs, so using these designs has always brought many problems and concerns for cement plants.

[0016] This design has created a more resistant and strong structure and creates a structural texture for the design of new generation immersion tubes, instead of the old inefficient designs to prevent interruption of cement kilns and sustainable production. This design permanently prevents the parts of the old immersion tubes from collapsing, and based on this new idea and thinking, immersion tubes are designed to last for years and work well without burning out, deforming, and collapsing.

[0017] The objectives of this invention include the following: a. Application of more resistant segment textures and elimination of weak segment textures b. Application of more resistant locking holders and elimination of weak holder tabs c. Application of more resistant materials and elimination of weak materialsSolution to Problem

[0018] This invention is designed and inspired by the resistant metal textures and the intertwined textures of military tank treads. It focuses on the known weaknesses of the old designs, by creating a permanent and resistant metal texture as the most ideal alternative for immersion tube old designs and prevents them from burning, deforming, and collapsing by creating a strong and resistant metal texture with special and unique capabilities, by eliminating all the weaknesses of immersion tubes old designs.

[0019] Innovation in the use of more resistant segment textures, locking holders and material:

[0020] In this invention we aim to achieve the defined objectives by inventing the resistant metal intertwined structure and texture called the structural segment plates, which include suspension plates and middle plates with cross-shaped stiffeners and locking protuberance of tetrahedral, locking mechanisms, strong segments with optimal dimensions and the use of steel with high refractory grade.

[0021] To strengthen the surfaces of suspension segments, cross-shaped stiffeners are applied, which are created in the middle of each segment. The mechanism of these stiffeners is such that by making the middle areas of the plates thicker in the cross-shaped form, in addition to creating structural strength and increasing resistance to wear and in terms of strength of materials, it also leads to a reduction in bending moment and shear forces and torsional forces in part.

[0022] In addition, to strengthen the surfaces of the intermediate segments crossshaped stiffeners are used, and upon the thickening of the middle areas of the plates in the cross-shaped form, as well as creating structural strength and increasing wear resistance, in terms of the strength of materials, it will lead to a reduction in bending moment and shear and torsional forces in the piece.

[0023] locking Protuberance of Tetrahedral -SLPT in the lower part of all middle and suspension segments provides resistant, strong, and intertwined conditions for connecting the structural plates of the immersion tube in the vicinity of each other. The connection method of these protuberances is based on a one-plate type connection, that is, by a single unit of pin and ring, a suspension segment will be able to connect to a middle segment in its lower row, which is a new type of connection.

[0024] One-Sided Locking Mechanism-OSLM including a one-sided pin and ring which works by two single pins and two locking rings, is assembled in a relatively loose manner and then the edges of the rings are welded.

[0025] Expansion Sliding Holes-ESH are considered in the area of the SLPT locking protuberance to cover the allowed transverse and longitudinal expansion gap. Expansion sliding holes are created for a collision-free connection between the plates of the suspension segment and the middle segment so that they can beeasily installed next to each other and neutralize the transverse and longitudinal expansion caused by heat.

[0026] Strength Segments with Optimal Dimensions-(SSOD) to increase the strength and very high-temperature tolerance in structural segment plates against thermal shocks and prevent burning and deformation, the most optimal recommended thickness is 20-25 mm maximum.

[0027] The utilization of High Refractory Grade Steel-(HRGS) using steel grades 1 .4848, 1 .4852, and 1 .4867 will increase the structural (static and dynamic) strength, temperature tolerance, and life span of all immersion tube parts.Advantageous Effects of Invention1 . It does not have the problems of burning, deformation, corrosion, creep, fatigue, collapse, and ovalization.2. Realization of management goals and strategies for maintaining sustainable production3. Significant and impressive effects in improving the production process4. Reducing and restraining the interruptions imposed on cement kilns.5. Cost-effectiveness of repair and maintenance operations6. Reduction of finished product costs7. Change in the productivity of the product8. Reduction of energy consumption (Saving Energy)9. Reduction of fossil fuel consumption and environmental pollution10. Increasing the profitability and prevent the waste of money and capital11 . Increasing lifetime and durability of immersion tube parts12. Enhancing work safety and protecting the lives of employed workers13. Reducing the risk of burning and collapsing immersion tube parts14. Reducing statistics of the consumption of expensive refractory parts15. The ease of making, supplying, transporting, and installing permanent immersion tube parts.Brief Description of Drawings

[0028] Fig.1 : Suspension and intermediate segment components, with locking protuberance of Tetrahedral, expansion sliding holes and cross-shaped stiffeners;

[0029]

[0030] Fig 2: Suspension segment components and intermediate segment with connecting pins and how to assemble them (front view);

[0031] Fig 3: Suspension segment components and intermediate segment with connecting pins and how to assemble them (back view);

[0032] Fig 4: Assembling method of the last row intermediate segment to the lower belt of the immersion tube;

[0033] Fig 5: Assembling method of bellhousing to Suspension segment and Suspension segment to intermediate segment, with connecting pins and rings;

[0034] Fig 6: Assembling method of all parts of Immersion tube with permanent structure to each other;Description of Embodiments

[0035] Parts components:1. Bellhousing2. Suspension segment with cross-shaped stiffeners3. Intermediate segment with cross-shaped stiffeners4. Locking protuberance of tetrahedral

[0036] The intermediate segments are connected to the suspension segment in such a way that the upper and right edge of the intermediate segment (3.B) is connected to the lower edge and the left side of the protuberance of the suspension segment (2.B) by a pin.

[0037] On the other side, the upper edge and the left side of the intermediate segment (3.C) are connected to the lower edge and the right side ofthe protuberance of the suspension segment (2.C) by a pin. This type of connection is similar in connection of the intermediate segments to each other.

Claims

Claims

1. Immersion tube device for rotary cement kilns with tetrahedral locking segment which comprising: a. Suspension plates with cross-shaped stiffeners; b. Intermediate plates with cross-shaped stiffeners and tetrahedral locking protuberance; c. Locking mechanisms; wherein the intermediate segments are connected to the suspension segment in such a way that the upper and right edge of the intermediate segment is connected to the lower edge and the left side of the protuberance of the suspension segment by a pin and on the other side, the upper edge and the left side of the intermediate segment are connected to the lower edge and the right side of the protuberance of the suspension segment by a pin.

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