Bucket Elevator: 七月 2015

2015年7月22日星期三

The Reasons for Bucket Elevator Head and Tail Wheel Wears Seriously

1.Serious wear problem is caused by the lack of lubricating oil in head to tail wheel, lubricating oil is used to reduce the effect of friction between the components, the working load of bucket elevator is focused on the two wheels, if lacks of lubricating oil, the friction will become greater, the hole that connect sprocket and main axis will be worn seriously, the head wheel and tail wheel will work in unstable condition, the lifted material will also fall down, so the head wheel and tail wheel must be well lubricated.

2. Material particles that conveyed by the bucket elevator is relatively large, the hardness is relatively higher, there will be few materials falling off from equipment during operation, since the sprocket is bigger, the material is very easy to hit the head wheel and tail wheel, after a long period of time the wheels will be deformed, so the material size of conveying material must match with selected bucket elevator.

3. Unsuitable construction material selection of tail wheel and head wheel, processing quality is not qualified, it is sure to have some troubles when use it, in addition, the strength for head wheel and tail wheel of the bucket elevator to bear is very large, low quality will surely has serious wear and tear with faster rate, so we must accurately calculate the pressure of sprockets to bear when the choosing head wheel and tail wheel and select appropriate metal material for processing technology to produce durable sprockets.

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Henan Pingyuan Mining Machinery Co., Ltd is the most professional manufacturer of Belt conveyor, and Vibrating screen, Bucket elevator, Screw conveyor, Scraper conveyor using the world's most advanced technology, we are willing to serve every company to meet your custom needs. Our goal is "be the future global leader of mining machinery industry". Have any questions, please contact us without any hesitation.

Features and Notes of Steel Cord Belt Bucket Elevators (2)

This article is the continuation of previous one which is more knowledge about features and notes of steel cord belt bucket elevators.

4. Middle casing: The design for casing is optimized with double channel in order to prevent the eddy current interference which caused by the belt with relatively high speed, and strengthening angle steel attached to middle casing. The casing of elevator should be checked regularly in order to examine if there is abnormal noise, and frayed or damaged.

5. Lower part device: Gear and rack tensioning devices have been used to adjust the tension synchronously. The tail pulley is designed with automatic centering device and attached with an anti-belt-deviation device and instrument that control the level of material. The step for checking the device must be done in order to examine the base of steel cord belt bucket elevator, to check whether it is damage, crack and whether the bolts are loosen or not.

6. Protection device: There are anti-belt-deviation in head and tail section of the main device. The signal will be sent to the control room when the belt deviation occur, and hence the power supply for the main device can be cut off immediately. There are material level control instrument and rotary switch at the tail section of steel cord belt bucket elevator. All the inspection exits must be check whether it is closed and sealed properly.

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Features and Notes of Steel Cord Belt Bucket Elevators(1)

1. Operation component: Special structure design that has been used in this part includes the high intensity tear-resistant steel cord belt with a customized belt joint and bucket fastener which enables the longer lasting of steel cord belt, the design and layout of bucket are reasonable with different arrangement to ensure the materials can loading and unloading continuously. The steel cord belt bucket elevator should be checked regularly to prevent abnormal noise or vibration.

2. Operation parts: The decelerator with hard tooth surface orthogonal shaft connected directly with the elevator shaft, with the help of hydraulic coupling to overhaul the machine and non-return device, structure of transmission device is compact which can achieve the flexible starting. The inspection must be done regularly to check whether the discharging of material flow of chute is normal, accumulated or blockage or not, and check whether the pressure in bucket elevators are negative or not.

3. Upper part device: The pulley is designed with automatic centering device. The material used for pulley is rubber capsule with high performance which has longer life span, the frictional force will be larger. The step to check whether any leakage occur in the elevator and decelerator, and the condition of lubricate oil level should be done regularly.

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The Traction Components and Tensioning Methods of Bucket Elevators (2)

This article is the continuation of previous one which is more knowledge about traction components and tensioning methods of bucket elevators.

3.Heavy hammer tensioning, heavy hammer directly putting the force on the part of lower bearing housing via its supportive stand, This resulted with the lower part is tied up with the respective components throughout its sprocket. By comparing to the hammer lever tensioning method, it has the same tensioning achievement, but it is heavier. Therefore, it has often been used at the plate chain elevator which has heavier components. Occupied smaller space and it is an automatic tensioning method.

4.Compound tensioning, it is a combination of heavy hammer and mechanical spring, the pressure is applying on the bearing at the lower part of the machine. And this causes the lower drive wheel to tie up. A set of compression spring is added in the between of heavy hammer and lower bearing, so that the tail part wheel axis contains certain buffering effect to overcome the pressure when it is overload. However, please remind that both sides of the hammer block have to be equal weight to prevent imbalance.

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The Traction Components and Tensioning Methods of Bucket Elevators (1)

The components of bucket elevator traction include rubber belt, ring chain, plate chain etc. In respect to TD rubberbelt bucket elevator, TH ring chain bucket elevator, and NE plate chain bucket elevator, the selected tensioning methods are different. This is due to the function of each bucket elevator is different. Currently, the common uses of tensioning methods are screw tensioning, heavy hammer lever tensioning, heavy hammer tensioning, compound tensioning etc.

1.Screw tensioning, the screw rod is installed at the bottom of machine, the nuts are fixed on the U-shaped slot of the supporting plate, the supporting plate can be adjusted horizontally by rotating the screw rod, the lower mechanical bearing is fixed on the supporting plate which can cause the lower pulley to tie up the component. This tensioning method is suitable for rubber belt bucket elevator, the rubber belt has certain elasticity which can adjust the tensioning screw rod to ensure the stability of rubber belt after being stretched.

2.The force of the heavy hammer lever tensioning is applied on the supporting plate, the lower bearing is fixed on the supporting plate, so that the lower part of the sprocket is tied up with the respective components. This is an automatic tensioning device. Since heavy hammer lever contains certain degree of mobility, therefore it must always maintain the tension of the compartment for good operation. Usually it is applied to the chain drive of the elevator. In order to have an efficient result, chain skidding and slipping off have to be avoided.

If you want to know more about the components of bucket elevators traction, please pay attention to our the latest FAQ.

It is published by PK machinery company.( www.pkmachinery.com)

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Do You know the Solution if Motor Base of Bucket Elevator Vibrates?

(1) The bucket elevator motor itself rotates abnormally, please take down the rotor and check the static balance.

(2) The installation precision of gearbox and the motor is poor, the centring exceeds the required range, please readjust the centring.

(3) The installation precision of motor base is not good enough, levelness exceeds the specified requirements, motor, please take down the motor and machine the motor base again.

(4) There is error in installation of sprocket, please readjust to guarantee the concentricity of large and minor sprocket.
(5) The sprocket tooth profile is poor, please take down the sprocket and machine the tooth profile again, to ensure the consistency of the tooth profile.
(6) The tightness degrees of sprocket is inappropriate ,please adjusted length and maintain moderate tightness.

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What Problems Will be in the Material Lifting Process of Bucket Elevator?

In the material lifting process of bucket elevator, there may be such problems: insufficient material lifting rate, insufficient material discharging rate and material leakage phenomenon, only they are resolved timely, the bucket elevator can have best effects. The reasons and solutions are as follows:

(1) insufficient lifting rate:

The material is likely to be caked on the bucket or chute, clean and remove the materials regularly according to caking condition. There is also possibility that the storage capacity of bucket elevator upstream equipment is insufficient which causes less feeding material, as result, the bucket elevator can not reach the design capacity, so we should try to improve the production capacity of upstream equipment. If the speed is slow, we have to change the speed ratio of the sprocket. Or it is caused by improper or wrong material calculation, check the calculator and material proportion, calculate again.

(2) insufficient material discharging rate:

The capacity of bucket elevator downstream equipment is small, make the discharge chute block, so we should improve the capacity of the downstream equipment of bucket elevator. It may also cause by small chute size or inappropriate chute angle, so adjust the discharging chute. There is also a possibility that the material is caked on the chain bucket or inside the chute, so we need to remove material and maintain the bucket elevator periodically.

(3) material leakage phenomenon:

If the material leaks from the gap of head section and bottom section, please add the sealing gasket or glue with sealant. Replace new sealing gasket, glue with sealant and tight the flange bolts if there gasket of bucket elevator flange is broken. If it is caused by large material feeding height difference and feeding pressure, please change the material feeding method and add the feeding buffer device.

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How to Trouble Shoot Bucket Elevator Belt Problems?

As a continuous conveying machinery for loose materials conveying equipment, bucket elevator has been widely used in food, feed, chemical and other industries, it is applicable to vertical conveying for powder, granular and small lump materials. The advantages of bucket elevator are: simple structure, high efficiency, low malfunction, etc. However, failure always happens in our daily operation which will affect the working performance. Here we will talk about the failures and troubleshooting of bucket elevator.

1.bucket belt deviation

A. Failure cause : The main reason of bucket belt deviation is that when bucket belt is stretched, the adjustment is not timely or not appropriate .

B. Troubleshooting: Adjust the tensioning device or gravity tensioning device at the bottom of the elevator, make the hopper with appropriate tightness and keep two axis of bucket elevator under parallel.

2. bucket belt slip
A. Failure cause: Bucket belt is too long or balance weight is too light.

B. Troubleshooting: If the bucket belt is too long, you can cut a section of belt and hang it well; If the balance weight is too light, you should add balance weight until you belt slip phenomenon is eliminated.

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Do You Really Know How to Maintain Bucket Elevator Chain and Belt?

Compared with the belt of bucket elevator, the chain is easier to maintain, so let's first talk about how to maintain the chain of bucket elevator. The chain is made of metal material, the biggest impact is the tensile strength between the scratches and the material in our daily operation, so we need to do two things when we maintain the bucket elevator.

1.Wipe with oil on the surface of the chain, the oil will form a protective layer on the chain surface, thus it can extend the period of the chain scratches cycle when bucket elevator works.

2.The molding of each chain ring is not made one time, we can find there is welding place on each ring of the chain, so we must pay attention to the usage condition of the welding place when we maintain the bucket elevator, if there is crack ,please repair welding timely.

Next we will introduce the maintenance method bucket elevator belt, as we know the belt is soft so it is easy to affected by buckets and conveying materials, sometimes there may have tearing phenomenon, here we have three solutions to solve the problems.

The first method is hot vulcanizing, it is a method by using of vulcanizing machine, hot vulcanizing material to repair seamlessly with high strength, this method can make the belt eliminate damage and recover completely .

The second method is to cold patching, which is mainly use special belt cold bonding agent ,glue and special tools to repair in filling type, if there is a small area of tearing, this method is very effective. The third method is mechanical repair using by rivet, screws or clip to connect the tearing parts or layer peeling parts together, but one shortage of this method is temporary usage, it can’t use for long-term.

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The Reason and Solution to Bucket Elevator Material Accumulation

(1) Uneven material feeding. When feeding is too much, the feeding rate exceeds the lifting capacity which makes material remain in surplus and accumulation, besides, the materials inside the base elevates gradually, the running resistance of the buckets increase gradually and reach a certain extent, the rubber belt will slip which will cause machine shut-down or motor burn-down.

Solution: Control the feed rate strictly, non-load operation first then open the gate of material incoming gradually. Observe material rising condition by the front inspection door. When material surface reaches bottom wheel unparallel axis line, the material feeding gate can’t be wide open any more.

(2) Large material returning flow will make material can’t flow to discharge pipe and return to the base, thus the base material is increased and will lead to blockage.

Solution: Reduce material backflow.

(3) When machine suddenly shut down due to power failure or other faults, the mass weight of lifting branch and the returning branch is unequal, which makes the bucket elevator reversed, the material inside the buckets return back to the base, it will lead to base blockage when you start the machine up again.

Solution: Installing a holdback device in the side of the elevator shaft to prevent bucket elevator reversals.

(4) Rubber belt slipping will reduce the lifting capacity of the bucket elevator, thus the material inside the base will increase and block.

Solution: Increase the tension, prevent belt slip.

(5) Big foreign lumped material enters into the base and causes blockage.
Solution: Install guard fences at bucket elevator inlet to prevent accidents.

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Operation Procedures of Link Chain Bucket Elevator

Please operate strictly according to the following steps:

1. Non-load running

After the completion of the installation work, then you can run without load. Before non-load test, please guarantee the chain rotates on the sprocket jogged run for around two weeks or more, when there is no touching or abnormal sound ,you can continue non-load running. During non-load running, please check the current and voltage of the main motor and make record, measure the temperature rising of the gearbox bearing parts and each bearing of bucket elevator head &tail section at the same time.

After the non-load running for 4 hours, if there is no abnormal phenomenon, you can stop, and tighten all bolts once more which fixed the buckets. Because buckets are in the right position now during non-load running, after tightening the screws well, non-load running once again for more than 4 hours, then stop. Tight the bucket connecting bolts again, then weld the bolts and nuts well by spot welding.

2. Load operation

Bucket elevator already meets the load operation after finishing non-load running, you can run with load after confirming there is no problem with other connected devices. At the start of the load operation the load should be increased from minimum to maximum gradually. In the process of load operation, the please measure the motor current ,voltage and the bearing temperature rising condition and make record, in order to make assessment of trial run, performance, and working condition for the whole machine.

3. Operation
1) Start-up

Bucket elevator will meet the normal operation conditions when load linkage test running is completed. 1-3 minutes non-load running is required before the normal work, then increase the feed rate gradually after operation becomes stable till reach full load operation.

2) Shut-down

Please confirm there is no remaining material inside the buckets after stopping feeding , then running for a period of time again and stop running to ensure that materials in the buckets are all discharged.

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Main Functions of Double Channel Bucket Elevator

Bucket elevator has two types, one is single channel, another is double channel. Double channel bucket elevator is the machine that has two channels, feeding on one side, and hopper descending after discharging on the other side. Double channel improves the strength of the middle section of bucket elevator, the ascending and descending of single channel bucket elevator are in one casing channel.

Lifting capacity of double channel bucket elevator is 30% higher than single channel under the same condition. If the lifting capacity of the standard bucket elevator is same to customers’ requirements after getting lifting capacity and height from customers, choosing double channel bucket elevator, which can not only reduce cost but meet customers’ requirements. For example, capacity customer required is 15 CBM/hr, and if uses TD160 single channel belt bucket elevator, it can be only 13CBM/hr. And the capacity of TD250 double channel bucket elevator can reach 25CBM/hr and meet customers’ requirements. The price of TD250 is much higher than TD160 and more energy consumption. However, efficiency of TD160 double channel bucket elevator is 30% higher than TD160 single channel bucket elevator, and less cost than TD250. So TD160 double channel bucket elevator can meet customers’ requirements better.

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The type selection principle of bucket elevator

The key to select the type of bucket elevator properly is that whether we can exert its service efficiency to meet the production requirements and improve production efficiency. The following aspects are how to select the type of bucket elevator.

1. Initial parameters

Material name; Material characteristics, it includes particle size (mm), bulk density ρ(t/m3), temperature, wetness, viscosity, etc.; The actual conveying capacity Q(m3/h); Need to lifting height H(m).

2. Hopper patterns

According to the wetness and viscosity of material, we select different Hopperpatterns. Anterior wall of shallow hopper has large slant angle and small depth,so this kind of hopper is suitable for conveying wet and poor flowing propertymaterial. The anterior wall of deep hopper has small angle and large depth, so this kind of hopper is suitable for conveying dry and good flowing property material. For the hopper with guide edge, it is suitable for conveying heavy andabrasive material.

3. Traction component types

According to lifting height and tempreture of material, we select different bucket elevator. The advantages of belt bucket elevator are low cost, operating smoothly, lower noise, etc.. Therefore, it is widely used in many industries. But its lifting height isn’t so high. On the contrary the plate chain bucket elevator has a high lifting height, and it can lifting large lump and high tempreture material.

4. Method of installation

According to technological requirements, we select different bucket elevator. It must add devices to support traction components when the traction componentsof inclined bucket elevator have large cable sag. So in general, we adopt rectilinear bucket elevator. When rectilinear bucket elevator can’t meet the special technological requirements, we adopt inclined bucket elevator.

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The introduction of plate chain bucket elevator

Plate chain bucket elevator is the most widely application vertically lifting equipments. It can apply to convey medium, large and abrasive material, such as limestone, cement clinker, lump coal, etc.. And the temperature of material should be no more than 250℃.

plate chain bucket elevator manufacturer

Features:

1.Large transport capacity: The lifting capacity is 100-1000m3/h;

2.Small drive power: It uses flow-through to feed material and inducement type to discharge material. And high-capacity hopper lays out densely. Therefore, there is little phenomenon of feeding material back or digging material. And then it can save 30% power than ring chain bucket elevator；

3.Long service life: There is little phenomenon of extrusion between materials through flow type feeding. So it can reduce the situation of machine wear. Plate chain bucket elevator adopts high strength wear resistant conveyor chain so that it can prolong the service life of link chain and hopper；

4.Wide application: It not only can lift powder and granule material, but also abrasive material and material which tempreture is no more than 250℃；

5.High reliability: It adopts advanced design principle and manufacturing method so that can ensure the reliability of the whole machine；

6.Good sealing: Lower pollution to environment；

7.Low comprehensive cost: Its use-cost is low because it has less power consumption and less maintenance.

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How to reduce the cost of bucket elevator effectively

Bucket elevator is widely used in the industrial production. And its facility cost and operation cost have become an an important part of enterprise production costs, account a large proportion. So we can reduce the cost through the corresponding way.

1. First of all, the type of bucket elevator must be suitable. We should know whether the power and conveying chain is suitable for material. If the model is too large, it maybe cause a waste of space; but if the model is too small, it will cause a waste of energy because it must divide material several times to lift.

2. Choose good quality equipment which the structure is easy to install and repair. And then it will reduce the loss that caused by damaging. Moreover, we must do the regular maintain so that we can reduce the damage of equipment.

3.We can calculate the optimal dosage when we operate the machine, so that we can ensure that the device has a high efficiency of coveying.

These measures can reduce the cost of bucket elevator effectively. In addition, our company have a good after sale service system that it can make its value improve further,which helps to reduce the cost of lifting machine. In this way, the end-user will have more confidence to buy our products, and the user's interests can be protected.

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How to deal with the phenomenon of bucket elevator returning material too much

The phenomenon of returning material in operating bucket elevator is that the material can’t completely discharge from the bucket elevator but some falls into the inside of machine. When lifting the material, if there is returning so much material, it will reduce production efficiency, increase power consumption and material broken percentage.

The reasons why there is returning so much material and the approaches to solve them are as following:

1.The speed of hopper is so fast. When the bucket elevator lifts different materials, the speed of hopper is different. In general, lifting dry powder or granular material, the speed is about 1~2m/s; lifting lump material, the speed is about 0.4~0.6m/s; lifting wet powder or granular material, the speed is about 0.6~0.8m/s. If the speed is too fast, the material will be discharged in advance and then causes the phenomenon of feeding material back. At this time, we should bring down the speed of hopper according to the lifting material.

2.The discharge tongue plate in die exit is installed improper. If the discharged tongue plate is far from dumped position, it will cause return material. So we should adjust the position of tongue plate in time.

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