The Main Characteristics Of Paper Machine Paper Machine Is The General Name Of A Complete Set Of Equipment That Enables The Pulp To Form Paper Webs, Including Headbox, Wire Section, Pressing Section, Drying Section, Calender, Paper Winder, Driving Section And Other Main Machines, As Well As Auxiliary Systems Such As Steam, Water, Vacuum, Lubrication And Heat Recovery.A Machine That Makes Paper From Pulp Water Suspensions That Meet The Requirements Of Paper Making Through The Processes Of Filter Screen Dehydration, Mechanical Extrusion Dehydration And Drying. The Paper Machine Includes Three Main Parts, Forming, Pressing And Drying, To Complete The Above Process, And Is Equipped With Necessary Finishing, Coiling And Driving Devices, As Well As Auxiliary Systems Such As Pulp Supply, Pulp And White Water Circulation, Vacuum, Ventilation And Exhaust, Paper Loss Treatment And Lubrication, And Automatic Control. The Specification Of Paper Machine Is Usually Expressed By The Width Of Paper Made, The Width Of Copper Screen And The Preferred Working Speed. The Width Of Modern Large Paper Machine Can Reach 11m, The Speed Of The Working Car Can Reach More Than 1000m/min, The Daily Paper Output Can Reach Hundreds Of Tons, And The Weight Of The Whole Machine Can Reach More Than 1000 Tons, Up To More Than 100 Meters. Small Paper Machines Are Widely Used In The Production Of General Developing Countries And Some Special Papers, With A Width Of 1~3m And A Working Speed Of Tens To 200 Meters Per Minute.

The Basic Structure Of The Paper Machine According To The Needs Of The Papermaking Process, The Paper Machine Has A Variety Of Structural Forms, Generally Consisting Of Parts Such As Flow, Forming, Pressing, Drying, Finishing, Coiling And Driving, And Auxiliary Equipment Such As Auxiliary Systems.Forming PartIt Is Composed Of Headbox, Breast Roll, Forming Net, Suction Tank, Couch Roll, Etc. The Headbox Distributor Uniformly Sprays The Slurry From The Flow System To The Forming Wire, And The Slurry Speed Should Match The Wire Speed. The Main Factor To Select Headbox Type Is To Control The Jet Speed And Wire Speed. The Fully Closed Hydraulic Headbox Adjusts The Pulp Speed By Adjusting The Pulp Feeding Pressure Of The Pulp Flushing Pump, Which Is Suitable For High-speed Paper Machines; The Air Cushion Headbox Regulates The Speed By Adjusting The Air Cushion Pressure, While The Open High Headbox Regulates The Speed By Adjusting The Pulp Level In The Box, Which Is Suitable For Medium Speed Paper Machines; Open Compartment Headbox Is Suitable For Low-speed Paper Machine. The Forming Net Is A Endless Ring Net. A Horizontal Or Slightly Inclined Flat Net Surface Is Formed Between The Breast Roll And The Couch Roll. As The Working Section Of Pulp Dewatering, It Is Used To Call It The Net Table, So It Is Called The Long Net. If The Endless Forming Mesh Is Placed On The Round Mesh Cage To Become An Arc Shaped Working Section For Dewatering And Forming, It Is Called The Round Mesh. If The Steel Mesh Drum With Holes Is Used To Pump Vacuum From The Shaft End To Accelerate The Dewatering Of Pulp On The Surface Of The Forming Mesh, It Is Called Vacuum Round Mesh Or Vacuum Forming Mesh. If The Pulp Is Clamped By Two Long Nets, And The Two Nets Are Dewatered And Formed At The Same Time, It Is Called The Net Clamping Former (fig. 2). These Shapers Use Different Types Of Dewatering Elements To Accelerate The Dewatering Of Pulp On The Web. Elements Can Be Divided Into Three Categories: Static, Rotating And Both. Static Elements Such As Dewatering Plate, Curved Vacuum Box, Etc., Rotating Elements Such As Table Roller, Vacuum Forming Roller, Etc. In Addition To Using A Single Formator To Assemble A Long Screen Paper Machine, A Round Screen Paper Machine, And A Screen Clamping Paper Machine, There Are Also Forming Parts For The Combination Of A Long Screen, A Multi Circle Screen, A Multi Clip Screen, And A Variety Of Long Circle Screen Hybrid Formators.Press SectionThe Formed Wet Paper Is Further Dehydrated By Pressurizing. It Consists Of Two Rolls With Hard And Soft Roll Surfaces, Such As Stone Roll And Rubber Roll. The Pressing Section Is Composed Of Pressing Groups Of The Same Or Different Forms, In Which Vacuum Suction Device Is Customarily Included. When Pressing, The Paper Sheet Is Supported By Wool Cloth Of Appropriate Specification, Which Can Evenly Distribute The Pressure And Take Away Part Of The Water Squeezed Out By Pressing, And Can Enhance The Pressure And Improve The Dewatering Capacity Of Pressing. Low Speed Paper Machines Usually Use A Line Pressure Of 20~60kn/m, While High Speed Paper Machines Use A Line Pressure Of Up To 210kn/m. When High Impact Pressing Is Used, For Example, The Line Pressure Of A Wet Sheet Machine Can Be Up To 350kn/m; The Rubber Covered Roll Is Made Into Vacuum Press Roll, Groove Press Roll, Lining Press Roll, Blind Hole Press Roll, Etc., So As To Effectively Take The Press Water Away From The Press Zone. These Are New Technologies Adopted Since The 1950s To Improve The Press Dewatering Efficiency. After That, A Double Press Structure Is Used To Form A Closed Paper Feed. It Is Composed Of Two Or Three Groups Of Pressing And Merging. The Wet Paper Is Stripped From The Forming Net By The Vacuum Suction Roller And Sent To The Composite Press With The Support Of The Wool Cloth. After That, The Paper Is Transferred Between The Press Rollers, Thus Eliminating The Phenomenon Of The End Breakage Caused By The Drag Of The Weight And Other Factors Between The Press In The Past. Since The 1980s, There Has Been A Wide Press Zone Pressing Technology. The Strong And Tough Rubber Belt Or Rubber Roller Deforms Under Strong Pressure, So It Has A Line Pressure Of Up To 750kn/m And A Wider Contact Surface. It Has Significantly Extended The Dewatering Time, Greatly Improving The Press Dewatering Capacity, And Has A More Prominent Effect On High-speed Paper Machines. The Paper Dryness Of The Press Can Be Increased From 30~37% To 43~45%, And Some Even Reach 50%. The Number Of Times The Paper Touches The Smooth Hard Roll Surface, Or The Number Of Times The Rough Glue Surface, And The Amount Of Water Loss On Each Surface Will Affect The Surface Quality Of The Paper. Reasonable Treatment Can Significantly Reduce The Difference Between The Smoothness Of Both Sides Of The Paper, And Vice Versa.Drying SectionA Group Of Drying Cylinders Driven By Gears Or By Woolen Cloth Forms A Drying Section. The Linear Speed Of

After The Paper Machine Has Been Installed And Operated For A Period Of Time, Various Meshing Points Of The Gearbox Have Leaked To Varying Degrees, Forming An Oil Accumulation Area At The Base Plate Of The Paper Machine. The Following Reasons Are Analyzed And Summarized:(1) Due To The Uneven Distribution Of The Mass Center Of Gravity Of The Drying Cylinder (the Weight Of A Single Drying Cylinder Is About 5 Tons), And The Drying Cylinder Is Heated By Steam, During The Operation Of The Equipment, The High-pressure Steam Forms Condensate In The Drying Cylinder, Which Causes Unfavorable Drainage Of Condensate During High-speed Operation, And Forms A Centrifugal Force In The Drying Cylinder. To Release This Force, The Drying Cylinder Can Only Move Towards Both Ends Of The Drying Cylinder, Causing Vibration Of A Certain Frequency At The Gear Mesh. Generally, Modern Multi Cylinder Paper Machine Is Composed Of 55-80 Cylinders, Which Produce Such Vibration Together During Operation, Resulting In Leakage At Each Meshing Position, Which Is Mainly Caused By Leakage;(2) As The Drying Cylinder Is Heated By Saturated Steam, The Steam Temperature Is 120 ℃ - 130 ℃. The Self Absorption Heat Of The Metal Frame In The Closed Steam Hood Can Reach 150 ℃, And The Thermal Expansion And Cold Contraction Make The Clearance At The Fitting Position Of Individual Parts Too Large (such As The Junction Between The Drying Cylinder And The Gearbox), Causing Leakage;(3) Sealant Is Applied Between The Mating Surfaces Of Various Parts Of The Gearbox, Which Causes Long-term High-temperature Vibration, Leading To Seal Failure And Leakage;(4) The Gear Box Is A Casting, Which Shall Undergo Aging Treatment During Production. If The Aging Time Is Short And The Internal Stress Of The Gearbox Is Not Completely Eliminated, The Installed Gearbox Will Continue To Deform During Operation, Resulting In Leakage;(5) During Installation Or Maintenance, Different Materials Of Bearing Gland, Gear Gland And Gear Shaft Will Lead To Different Coefficient Of Thermal Expansion During Operation. Therefore, The Expansion Clearance Is Required To Be Greater Than A Certain Standard During Installation. In The Actual Operation And Installation Process Of The Gearbox, Due To Improper Maintenance And Installation Process, The Expansion Clearance Is Less Than The Standard Value, Which Will Cause The Gearbox To Bear The Strong Expansion Force Of The Components In The Gearbox During Operation, Resulting In Deformation And Leakage;(6) In Order To Ensure The Sealing Effect Of The Junction Surface Of The Gearbox, The Elongation Of Each Cold Tightened And Hot Tightened Bolt Is Also Clearly Specified. However, In The Actual Maintenance Work, If The Bolts Are Not Tightened As Required, The Joint Surface Will Deform And Leak.

On Site Repair Is A Rising Maintenance Mode. Its Principle Is To Use Polymer Composite Repair Technology To Repair On Site Without Dismantling Damaged Equipment Or Components. The Intermolecular Force Formed By The Polymer Penetration Of The Composite Material For Repair Makes It Form Excellent Adhesion With The Repair Parts, Meeting The Requirements For The Equipment To Bear Various Composite Forces During Operation. This Kind Of Repair Material Is Reliable Based On The Performance Of Fusiblue Polymer Composite.The On-site Repair Accuracy Is Guaranteed Through Several Links: The Repair Position Is Firm And Reliable, And The Metal Surface Is Clean And Dry.