Accident Analysis and Prevention Belt

Underground mine belt conveyor is mainly fire-prone areas, because of its sudden, rapid development, pose a threat to the underground workers, and even induced due to the spread of fire and gas explosion is possible. Result in a fire accident was caused by the ignition source has enough calories to make tape burn. Skidding accidents are a major factor in generating enough heat, tape slippage is due to loose or tape jam large load caused by the tape tensioning device due to loose tension force generated by the elastic elongation of the tape is too small and too large; large load First, because of heavy start, the second is due to load is too large, three is the tape and active roller, driven roller idler friction between too small, such as tape inside surface water or oil, the driven roller bearing damage or childcare roll damage; tape jammed tape is mainly buried in coal or in the mud, so that the tape can not run. Another electrical equipment sparks, electrical short circuit may also cause the conveyor fire.
1.2 belt run cause of the accident
Runtime Belt Conveyor deviation is the most common faults. Deviation accidents occur frequently, it will affect the life of the conveyor, severe outage occurs or is likely to result in personal injury or death. Causing belt run three main reasons: First, the device itself aspects, such as the outer cylindrical drum larger error, roller rotation is not flexible, proactive and driven roller drum axis parallelism error is larger, etc.; Second, installation and commissioning aspects, such as roller, roller, rack installation does not meet regulatory requirements, in addition to vent coal biased position of the mouth, causing the tape to make partial load deviation; Third, maintenance, mainly due to the cleaning is not timely, transport Machine Drum Machine roller-stained dust, resulting in local diameter Ambassador belt run.
1.3 Tear cause of the accident
Tear tape main reasons: First funnel badly worn, resulting in waste rock and coal gangue direct hit tape or card tape and other items caused by tearing; Second, serious deviation is scraped tear tape; three tape joint strength is too low or because the load is too large to make tape joints broken.
Prevention
2.1 Fire accident prevention
1) using fire-retardant tape, even in the event of fire, it will not be able to control the fire rapidly.
2) strengthen the maintenance of electrical equipment, to prevent fires caused by electrical accidents.
3) strengthen management, to keep the roadway clean, tape no floating coal, water, no oil, no debris, nose, tail no heap coals. Improve the quality of operation and maintenance personnel to maintain good running condition conveyor.
4) conveying confidential installation inspection and monitoring devices, such as drive rollers and driven roller temperature monitoring devices, smoke alarms and fire in the event of an automatic sprinkler system.
2.2 Deviation accident prevention
1) confirmation by the state purchase of qualified products, avoid the lack of precision equipment manufacturing belt deviation caused by an accident.
2) Install the installation process to focus on the dimensional accuracy:
a. installation tape found at the deviation in the drum, the drum should be corrected and equal degree of levelness, drive pulley, steering cylinder installation requires its width tape centerline coincides with the centerline of not more than 2mm, its axis line and tape The vertical center line of the drum is no more than a fraction of the width, the horizontal roller shaft of not more than 0.3/1000.
b. If you find that tape to the side of the no-load total deviation should be adjusted idler bracket.
c. If you find no deviation tape at no load, and heavy load to the side of the deviation, indicating that the tape appeared partial load, coal hopper vent should be adjusted to the position.
3) strengthening routine maintenance:
a. timely removal conveyor rollers, roller, splice at other major parts of the dust, and prevent the roller, roller-stained dust lead belt run.
b. timely adjustment of tape running deviation phenomenon occurs, promptly check the tape edges and joints wear, identify problems and timely replacement and repair.
4) Install belt run the monitoring device, once the belt run off the alarm signal to alert maintenance personnel to take action.
2.3 Tear accident prevention
A) timely repair worn funnel, avoiding direct coal gangue and pound the tape.
2) the timely processing of deviation fault, not tear tape.
3) Set the tape longitudinal tear monitoring devices, found fault timely manner.

Troubleshooting belt conveyor

To address such failures is important to note the dimensional accuracy of installation and daily maintenance. There are several reasons for deviation, to be based on the difference between handling different reasons.
1 Adjust the belt conveyor idlers bearing Belt Conveyor in the middle of the entire belt conveyor idlers deviation, adjust the position to adjust the deviation; idlers in the manufacture of both sides of the mounting holes are worked into holes for be adjusted. Specific adjustment method, the specific method is biased which side of the belt, idlers which side of the belt toward the forward direction forward, backward, or the other side. Figure 1 shows the direction of the belt upward deviation is lower roller group should be located at the left, the upper roller group moved to the right place.
2 Install aligning roller group aligning roller group has many types such as an intermediate shaft type, four-link, vertical roller type, etc. The principle is the use of block or roller rotates in the direction in the horizontal plane lateral thrust block or generate the Automatic belt adjustment belt deviation reaches to the heart of the purpose. Average total length of the belt conveyor or belt conveyor shorter run time using this method bidirectional more reasonable, because the shorter belt conveyors easier deviation and not easy to adjust. And long belt conveyor is best not to use this method, because self-aligning roller group life belt use would have some impact.
3 Adjust the drive pulley and the driven pulley and bend pulley position adjustment bend pulley belt deviation adjustment is an important part. Because a belt conveyor with at least two to five rollers, all the rollers must be perpendicular to the installation location of the longitudinal direction of the belt conveyor centerline, if the skew is too large deviation inevitable. Adjustment Method and its group of similar idlers. For the head drum as the drum belt deviation to the right, the right of the bearing should be moved forward, the belt deviation to the left of the drum, the left bearing housing should be moved forward, also the corresponding After moving the left or right side bearing housings after the shift. Rear roller adjustment method and the head drum opposite. Adjustment method. After repeated adjustments until the belt transferred to an ideal location. Adjust the drive or bend pulley in the best pre-install its exact location.
4 tension belt tension adjustment at the adjustment at the conveyor belt deviation adjustment a very important part. Hammer at the upper two tensioning idler pulley in addition to other than perpendicular to the longitudinal direction of the belt should be perpendicular to the vertical line of gravity, which is to ensure its axis horizontal centerline. Tensioning screw or hydraulic cylinders with tension, the tension of the two roller bearing shall simultaneously pan, to ensure the longitudinal direction of the drum axis and perpendicular to the belt. Specific method of adjusting the belt deviation adjustment of the drum at similar.
5 reprinted point blanking position on the belt deviation of reproduced material blanking at the point position on the belt deviation has a very big impact, especially in the two belt conveyor in the horizontal plane perpendicular to the projection of a greater impact. Usually reproduced points should be considered down two belt conveyor relative height. The relative height of the lower horizontal velocity component of the material the greater the impact on the lower side of the belt is greater, while the material is difficult to center. The cross section of the material on the belt deflection, resulting belt deviation. If the material is biased to the right, then the belt deviation to the left, and vice versa. In the design process should be possible to increase the relative height of two belt conveyor. In space-constrained mobile bulk material handling machinery down funnel, guide trough and other pieces of form and size should be seriously considered. General guidance for the width of the trough belt width should be about two-thirds more appropriate. In order to reduce or avoid the belt deviation increase blocking plate blocking materials, changing direction and position of the whereabouts of the material.
6-way running conveyor belt deviation adjustment bidirectional running belt conveyor belt deviation adjustment than the one-way conveyor belt deviation relative to the adjustment much more difficult, specific adjustments should be adjusted in a certain direction, and then adjust another direction. Adjust the belt to carefully observe the movement direction of the relationship with the deviation trend, individually adjusted. Emphasis should be placed on the drive pulley and bend pulley adjustments, followed by the adjustment of the roller and the material blanking point adjustment. Also note that the belt when the belt curing joint cross the longitudinal direction of the force evenly in the use of both sides of the chain traction force equal as possible.

The working principle and structure of belt conveyor

Belt Conveyor is used as traction mechanism and bearing a continuous transport machinery sector, which is the main transportation equipment of bulk materials, with continuous operation, transport capacity, running resistance, low power consumption, smooth operation, transport en route to the materials in the crushing of small, easy to realize automatic control, etc., are widely used in coal, metallurgy, port transportation, building materials and other departments. With the development of national economy and scientific and technological progress, belt conveyor applications will become increasingly widespread.
Conveyor works as follows: The head belt around the drive pulley and tail redirecting roller Jane endless belt to form a non-polar, while the upper and lower belts were supported on the upper and lower rollers, the tensioning device In normal operation to the desired belt tension. When the drive unit driven by the drive roller rotates with the drive roller and the friction between the belt and the conveyor belt running along the above goods, goods are carried on a conveyor belt to the nose, due to steering belt is achieved Uninstall.
The fuselage cross-section belt. Cargo transported on conveyor belts, conveyor belts called this part of the working section or heavy segment; under the conveyor belt transporting goods is not known as an empty segment.
Can be used for horizontal and inclined belt conveyor transport. Typically, the transportation of coal along the inclined, the angle is not greater than 180, is not greater than 150 downward transport, transporting drilling significant adhesion and large materials, inclination can be appropriately increased.
Belt disadvantages are: conveyor higher cost and easy damage, should not be hard, angular materials transportation; compared with other devices, higher initial investment, but can not be used too much inclination occasion.
Many types of belt conveyors, scope and characteristics of each are not identical. The main types are: common type conveyor, belt conveyor frame hanging rope, retractable belt conveyors, powerful conveyor, wire rope conveyor, belt conveyor intermediate multi-stage driver and large cushion belt conveyor and so on.
With the rapid development of China's coal industry, mine traffic increasing, in a large pit on the main level and sloping roadway, using a large volume, long-distance belt conveyor is extremely beneficial, steel cord conveyor belt is to adapt kinds of needs and design a powerful belt conveyor. It is the common type of belt conveyor difference is that it uses steel cord conveyor belt instead of the ordinary, its tensile strength than the ordinary type increased IL times, even in recent times, greatly improved conveyor transmission capacity.

Dynamic analysis of belt conveyor main problem to be solved

Belt Conveyor dynamic analysis of the most important feature is the change in the previous study each component individually designed patterns to various components of the conveyor the best way to work together for the ultimate goal, the conveyor as an organic whole to conduct a comprehensive analysis, find the optimal combination of model and control strategy in the economic, reliable conditions, to improve the overall performance of the conveyor.
Dynamic analysis in modern belt conveyor design to solve the main problem between the following aspects:
(1) Calculate the transport conveyor driven in operation of the peak value and the tension condition occurs. Conveyor drive tension peak is generally several times its normal operating tension or even ten times, and according to the way the previous static design tension value calculated is much smaller than the actual value, we can only increase the safety factor to ensure delivery safe operation of the machine. In the absence of reliable analytical tool in the case, the use of empirical methods to determine the factor of safety is often made too large, it will inevitably result in increased costs, waste of investment.
(2) analysis of the vibration conveyor belt running it special law. Vibration is causing tension increase was mainly driven conveyor, belt accident is caused by the culprit, find out the rules for the effective control of its dynamic tension the belt of great significance.
(3) study the boundary conditions on the conveyor belt vibration regulation impact. Boundary conditions conveyor belt means all affect the dynamic characteristics of internal conditions and external conditions, such as driving, tensioning devices, roller, load and so on. To analyze the changes of these boundary conditions on the vibration impact and vibration conveyor find optimal hop's best special form of the boundary conditions.
(4) the boundary conditions optimized working conveyor through dynamic analysis to determine the best configuration for transport subsystem.
(5) based on comprehensive analysis of the results of the evaluation, selection and reasonable belt conveyor structure and configuration, so that in performance and comprehensive economic indicators optimal.

Small flour mechanical friction exists deputy campaign

Small Flour Mill mechanical friction exists deputy campaign . Small flour machinery in motion frost deputy campaign to overcome the friction part of the energy is consumed , which is part of the energy is converted to heat to the temperature rise deputy campaign Gao , leading lubricant failure , changes in material properties , so that the flour machine working conditions deteriorate, while the friction causes wear and damage to the surface of the component motion pair geometry and surface quality of children , that the deputy campaign is not working properly and failure. From this point of friction is a harmful factor. Flour machine design in order to reduce friction and it has been hard .
  In normal daily life and certain aspects of T process , the friction also play a useful role is indispensable . For example , flour machine fastening , connection , belt drive , compact flour machinery brake , the car traveling on the road and rolling of steel is the use of friction , etc. The typical example of indium . In these cases, people and efforts to increase the friction in order to ensure produce reliable , sufficiently large friction.

Small flour machinery in use for troubleshooting common faults have the following

1, the motor temperature fault is one of the main motor damage . Reasons caused by high temperature bearings in oil , the bearing into the dirt , bearing damage , motor overload .
  2 , cleaning sieve failure
    ( 1 ) cleaning sieve screen frame vibration or shaking . Due to loose bolts or wedge .
    ( 2 ) wheat were broken too . Due to the wheat board and the sieve device tooth gap is too small , too large sieve or damaged.
    ( 3 ) with a grain of sand and gravel . The reason is a small row of stone damper inside the mouth , or Screen angle inappropriate.
  3 , spiral agitator failure
    ( A ) a non-exclusive food grain port . Motor rotates in the wrong reasons , the discharge port congestion, agitator blade breakage .
    ( 2 ) agitator shaft does not turn, causes feeding excessive belt slippage .
  4 , Flour Machinery malfunction
    ( A ) not less powder or flour . Common cause of clogged sieve .
    ( 2 ) Fault Closed Closed Wind Wind poor side bags may be sucked on . Common causes of air leakage at the connections , impeller wear.
    ( 3 ) flour and high temperature. Should loosen the roller , such as roller should be repaired or replaced badly worn ; machines shut down when the high temperature heat .
    ( 4 ) body shaking. Tighten bolts with the rack grinding .
    ( 5 ) yields. Tighten the spring , ensuring consistent roller gap at both ends of the worn grinding teeth to be repaired.
    ( 6 ) no bran. Common causes spindle turning wrong, or mesh sieve frame Mifengbuyan damaged .

Food processing machinery troubleshooting measures

Flour Mill Equipment in the use of the Central Standing Committee some small problems do not occur in mechanical equipment damage or failure , but improper use or maintenance is not in place due to these problems are easy to solve.
If less flour machine flour or no flour , the main screen is blocked , flour can not be screened out . After the shutdown of the screen removed to clean up on it.
Flour machine to work properly, but the flour yield than previously declined. This situation is mainly due to grinding teeth wear too big a gap between the roller causes. The solution is : compression spring , to ensure both sides of the roller gap , like or re- drawing .
If the temperature is too high, the output of flour , a machine running time is too long , the heat caused by too much , another reason is the gap between the small roller caused .
Flour Machinery just out of flour, bran does not come out , this is the mesh screen frame Mifengbuyan damaged or caused , for a screen on the line.
If you shake flour machine , you should check for loose screws , and if loose , tighten the screws on it.

Bucket elevator Fault Analysis and Treatment Methods

1, the operation occurs when abnormal sound
(1) Bucket Elevator bucket chain base floor and collide, adjusting the base of the elastic device, so that the chain tensioner.
(2) drive shaft, a driven shaft key relaxation, sprockets displacement, bucket and chassis collide. Adjust sprocket position, the key fitted tight.
(3) guide plates collide with bucket chain, trimming guide plate position.
(4) with bucket chain guide plate sandwiched between materials, materials amplifier inputs seat angle.
(5) bearing failure can not be flexible operation, replace the bearings.
(6) blocks or other foreign material on the machine base shell stuck, stop foreign body removal.
(7) sprocket (drive and driven sprockets) of the tooth is not correct, amend or replace the sprocket tooth sprocket.
(8) drive sprocket and chain off the bad teeth, fix sprocket tooth.
(9) drive chain generates idling adjust the chain length.
(10) chassis is not properly installed, align the vertical length of the chassis.
2, the vibration motor base
(1) Rotate the motor itself is bad, remove the rotor inspection static balance.
(2) Reducer and motor mounting accuracy is poor, in excess of the specification, readjust.
(3) lack of precision motor base mounted, horizontal exceeds regulatory requirements, re-adjust.
(4) there is an error installing the drive sprocket, need to re-adjust.
(5) drive sprocket tooth bad, need to be corrected tooth.
(6) drive sprocket tightness inappropriate and should be adjusted.
3, the leakage gray
(A) full-length chassis flange gasket damaged or missing pads, replaced with new pads, coated sealant, re-tighten the flange bolts.
(2) material from the nose, the gap at the base of the escape, increasing gaskets or sealant coating.
(3) The height of input materials is too large, increasing the feed pressure, the need to change the material into ways to increase the feed buffer device.
4, to enhance the capacity of less than design capacity
(1) material bonded to the chain bucket and downpipe, according to the degree of adhesion, periodically clear materials.
(2) bucket elevator machinery front of insufficient capacity, causing less material inputs that elevator to reach the design capacity, the need to try to increase production capacity before the machine equipment,
(3) enhance the speed is slow, need to change the speed ratio of the transmission chain.
(4) improper material measurement method, or measurement error, check the meter, check the proportion of materials, revised the calculation methods.
5, the material discharged insufficient
(A) to enhance the ability of small rear of Seed coating machine and equipment, so that the discharge valve is blocked, the rear of machinery and equipment to improve production capacity.
(2) discharge opening angle downpipe downpipe is too small or not suitable correction nesting downpipe.
(3) material adhered to the bucket and downpipe, the need to regularly clear the materials.

Bucket elevator works

Bucket Elevator for conveying powder, granular and small block of non-abrasive and small abrasive materials. TH is a type of ring chain bucket elevator use of hybrid or gravity discharge, digging loader. Tractor parts with high quality steel ring chain. Central case of single-, dual-channel two forms of machine hammer box Constant automatic tensioning. Sprocket rims interchangeable modular structure. Long life and easy replacement rim. The lower the gravity automatic tensioning device, to maintain a constant tension, to prevent slippage or from chain, while the hopper stuck encountered phenomenon caused by accidental factors have a certain tolerance so that resistance, can effectively protect the lower shaft member. The bucket elevator for conveying bulk density of less than 1.5t/m3 easy to dig a powder, granular, small block bottom abrasive materials. Such as coal, cement, gravel, sand, fertilizer, food and so on. TH-type bucket elevator for a variety of vertical transport of bulk materials. Suitable for conveying powder, granular, small block materials, classic statement material temperature below 250 ℃.
Bucket elevator conveyor working principle is: the material from the hopper to scoop up the following storage medium, with conveyor belts or chains upgraded to the top, flip down after bypassing the top wheel, bucket elevator material is poured into the receiving groove inside. Belt bucket elevator drive transmission belt generally use rubber band attached to the lower or above the upper and lower drive roller and the idler pulley. Chain bucket elevator drive with two generally parallel transmission chain, or following a pair of drive sprocket, under or on top of a pair of headed sprocket. Bucket elevators are generally equipped with chassis, in order to prevent the bucket elevator in dust.

Use and maintenance of the screw conveyor points to note are those

Screw conveyor is used for conveying powder , granular, small block materials, general-purpose transportation equipment, all kinds of bearings are in the dust in the work , so the working conditions so reasonable operation and maintenance of the screw conveyor to a more great significance , screw conveyor operation and maintenance of the main requirements are as follows :

    1 , please use the screw conveyor , on normal operating procedures to operate, and often observe the screw conveyor is abnormal condition exists. If there is an abnormality please shut down for inspection, troubleshooting before operation.

    2, please pay attention to safety , do not place your hands or other objects into the rotating parts .

    3 , during use , screw conveyor is strictly prohibited heavy start , start feeding should be preceded by the host , and then feeding ; should be checked before the start of the cylinder body I is too much material .

    4, in order to ensure no load starting screw Fluting machine requirements , conveyor feeding should be stopped before stopping , and other material inside the chassis rear was completely lost all stopped .

    5 , in strict accordance with the mixer loading capacity : no more than the effective volume of the mixer used under strict overload use , it would burn or damage the gear motor and other components . After adding the material must remember not to stop halfway , try to avoid overloading the next start-up.

    6 , the initial feed screw conveyor , the feed rate should be increased gradually until it reaches the conveying capacity , feeding should be uniform, or likely to cause transport of materials product plugs, drive overload .

    7 , the material being transported shall not be mixed with chunks of hard materials to avoid causing death card spiral screw machine damage.

    8 , the normal operation of 1800 hours conveyor should be a small repair , mainly to check lubrication or replacement of wearing parts ;

    9 , the normal operation of 4000 hours should be overhauled , mainly for all assemblies demolition inspection and cleaning, replacement or correction of all wearing parts and standard parts .

    When removing the screw conveyor please remember the clear sequence , while the reverse order when assembled can be combined . The local host helix and direction of rotation of the feed screw should follow the direction signs, strict reverse direction !

Belt conveyor is probably how correct standard operating

In industrial production , often because the operation is not standardized , resulting in a number of security incidents site today tell us about the safe operation of the conveyor belt , cuts in production safety hazard.

First and foremost, before the open belt conveyors , belt conveyors to recognize in a normal situation , the various components are not damaged , circuit, gas supply voltages are in the preparatory position open belt conveyors caliber power .
After an open Belt Conveyor , it is necessary to follow strict rules by the line of operations:

1 Close the total power , look at all the hours of operation the power light conditions, see the end , admit and correct and then the following operations

(2) The second step of each loop is closed by one power switch, view the LEDs and the belt conveyor is not a unusual. Under normal circumstances are: inverter and other equipment power indicator light, the inverter panel show normal appearance ( no fault code appears ) , belt conveyor operation indicator is not lit , the device does not operate.

3 By launching the process in accordance with electrical equipment , electrical equipment launched on a normal ( motor or other equipment has reached the normal speed , normal conditions ) and then the next one to launch electrical equipment .

In the belt conveyor operation, it is necessary to abide by the items are shipped items depicted in the rules and abide by the ability to depict the belt conveyor . Secondly, we must pay attention to all categories of personnel not touch the belt conveyor movement somewhat , non-professionals are not free to touch electrical components , control buttons, etc. . Eventually, the belt conveyor operation of the inverter can not break after the class , if it decides that needs repair , it is necessary in the case of suspension frequency operation carried competence , or can damage the drive .