Design,Analysis And Structure Optimization Of Circular Straight Tooth Refining Plate Of Defiberator

The Medium Density Fiberboard is being deleloped very rapidly after it was published at twenty century seventy years, and brings huge impact to particle board. With the development of Medium Density Fiberboard, The Defiberator is developed very rapidly. After fifty year's development, The Defiberator has been a high-tech Defiberator system with a lot of good points, such as high speed, large-sized, exact, high-efficiency, automatic, numerical control and safe. With the ripenice of Defiberator's technic, the size of the product line of Medium Density Fiberboard is enlarged gradually. But a lot of the product lines are imported from overseas. The reason is that there is a big distance between homebred Defiberator and overseas Defiberator. The refining plate is the most important factor which impacts the capability of Defiberator. We have not mastered the key technic of refining palte, and we have a lot of defference from the advanced international level in many aspects, such as the refining plate's manufacturing presicion, the refining plate's structure design, attrition performance, energe saving, life etc.The dissertation studies the work theory of defiberator, discusses the mechanism of fiber separation, mechanism of refining plate abrasion, and discusses the material types of refining plate, and chooses a feat one.Based on the characteristic of fiber and the rotation speed and the power of the electromotor, design the tooth structure of the refining plate, and establish the 3D modal of the refining plate and analyse it. Based on the thermal analysis, optimize the structure of the refining plate to ensure that the mass of the refining plate to be minimal and satify the stress and displacement restrictions and decrease the inertia force of the refining plate. The dissertation is presented as follows.(1) The dissertation discusses the mechanism of fiber separation, which is the theory base and gist of designing the refining palte. And discussed that how the capability parameter of Defiberator impacts the quality of fiber,find that the quality of fiber will be improved if the diameter and the rotate speed are increased, and discusses the character of material that refining plate uses, and the mechanism of refining plate abrasion, then found the factors which impact the abrasion of refining plate.(2) Based on the work characteristicof the refining plate, according to the requirement of fiber and the power and rotate speed of the motor, designs the tooth structure of theφ900 refining plate. The tooth structure is circular straight tooth.(3) Based on the designed refining plate, creates the 3D parameterized modeling by ANSYS, and meshes it. Because the refining suffers complex force, Based on the perfect force, this dissertation does the static power analysis to ensure if the stress satifies the demand.(4) The defiberator works in the high temperature environment, and generates friction heat. The friction heat affects the life of the refining plate.Based on the friction heat and the work environment of refining plate.This dissertation analyses the heat stress of refining plate, and gets the result of heat analysis as the body force to analyse the feat deformation, and get the displacement in the X and Z direction. Based on the result, we can confirm the clearance between each refining plate when we install them, and adjust the clearance between the immobile and mobile refining plate from time to time to avoid hitting each other.(5) When the clearance between the mobile plate and immobile plate is too small, the friction feat will be transferred difficultly. The refining plate is not working in natural instance. From the analysis result, we can find that the refining plate bends to the heat source direction, so does the immobile refining plate. Because the X direction is restricted, so the expanding direction is in the Z direction, then the mobile refining plate will hit the immolie one to result in breacking the tooth. So to the conclusion, the clearance between the two plates can not be too small.(6) On the base of hot stess analysis of refining plate, the dissertation optimizes the structure of refining plate by ANSYS. Assumes the maximal stress and displacement in the Z direction as the state variable; assumes the height of tooth and the height of plate as design variable; and assumes the volume of the plate as objective function. Based on the every restrictive condition, the dissertation optimizes the refining plate to ensure the improved plate to be light-duty.