What Is a Ladder Hoist?

A hoist (well elevating conveyor / Elevator) is a large-scale machinery and equipment that can be transported by changing the potential energy, such as a mine elevator, a dam crossing elevator, and the like. Broadly speaking, elevators, cranes, hoists, stable cars, cranes, hoists, etc. can all be called hoists. Hoist generally refers to large mechanical equipment with large power and strong lifting capacity. The flexible parts are driven by the power machinery to move the steel wire rope and the goods to be transported up and down to complete the transportation process. The steel wire rope is an indispensable and important part of the lifting machinery. Wire rope and so on.

HL type ring chain machine

HL ring chain centrifugal bucket elevator consists of moving part (hopper and traction chain), upper section with transmission sprocket, lower section with tensioning wheel, intermediate casing, drive device, backstop Moving device. The hopper of the hoist is arranged intermittently, and it is loaded by the "pulling method" and unloaded by the "centrifugal feeding method". The traction mechanism of this elevator is two endless chains.

TH series bucket elevator working principle: TH series bucket elevator is suitable for conveying powdery, granular and small blocks of non-grinding and small-grinding materials. TH type is a circular chain bucket elevator with mixed or gravity unloading and digging loading. High-quality alloy steel high-end ring chain for traction parts. The central casing is divided into single and double channels, and the internal weight of the hammer box is automatically tensioned. The sprocket adopts interchangeable rim combination structure. Long service life and easy rim replacement. The lower part adopts an automatic gravity tensioning device, which can maintain a constant tension force to avoid slipping or disconnection. At the same time, the hopper has a certain tolerance when it encounters a jam phenomenon caused by accidental factors, which can effectively protect the lower shaft and other components. This bucket elevator is suitable for conveying powdery, granular and small block-shaped bottom-grinding materials whose bulk density is less than 1.5t / m3, which is easy to extract. Such as coal, cement, crushed stone, sand,

The maintenance of the machine is an extremely important recurring task. It should be closely coordinated with extreme operation and maintenance. Full-time personnel should perform on-duty inspection.

Bucket elevator

The hopper lifts the material from the storage below, and as the conveyor belt or chain is lifted to the top, it bypasses the top wheel and then turns down. The bucket elevator dumps the material into the receiving tank. The driving belt of the bucket elevator with transmission is generally used

Bucket elevator consists of casing, traction member (conveying chain), hopper, driving wheel (head wheel), redirection wheel (tail wheel), tensioning device, guide device, feeding port (feeding port) and discharging port (Discharge outlet).

a. Cylindrical bucket: deep bucket, the bucket mouth is inclined at 65º, the depth is large, and it is used for drying.

1. The elevator is maintained and managed by designated personnel, and the key of the power switch box is managed by designated personnel.

2. The hoist must have a hoist limiter and a stroke limiter. The limiter should enable the pulley to stop automatically when it is lifted to a distance of 300 mm from the drum or pulley. The action is sensitive and reliable, and the test is carried out.

3. The hoist should have the maximum load mark, and the weight should not be overloaded (1T) during lifting and landing.

4. After powering on, check safety devices such as hoist limiter, travel limiter, interlock switch, etc.

5. Before hoisting and landing, the driver can only drive after the alarm is sounded.

6. The hoist is absolutely not allowed to carry people up and down.

7. After work is completed, the hoisting plate of the hoisting machine should be dropped to the ground, then cut off the power and close the upper and lower guardrail doors.

8. Always keep the environment around the hoist clean.

1. Drive at no load. Therefore, all the materials in the hopper should be exhausted before each shutdown, and then stop.

2. Can't be reversed. Chain derailment may occur during inversion, and it is troublesome to troubleshoot derailment.

3. Feed evenly. Do not increase the feeding amount suddenly. The feeding amount cannot exceed the conveying capacity of the hoist. Otherwise, it is easy to cause a "stuck car" accident when the material accumulation at the bottom is serious.

4. Replenish lubricating oil in a timely manner.

5. When the chain and hopper are severely worn or damaged, they should be replaced in time.

Elevator failure

The improper installation of the head and bottom drive shafts of the hoisting machine can easily cause the hopper belt to run off. The main manifestations are: the drive shafts of the head and bottom wheels are in the same vertical plane and are not parallel; In the same vertical plane; the two transmission shafts are parallel, in the same vertical plane and not horizontal. After the above situation occurs, the hopper belt deviates, which easily causes the hopper and the barrel to hit and the hopper belt torn. In addition, the head of the hoist is subjected to a large dynamic pressure, up to about 100 tons. Due to the long-term operation, it is unavoidable that squeeze wear occurs in the bearing position.

Traditional methods are repaired after repair welding or brush plating, but both have certain disadvantages: the thermal stress generated by the high temperature of repair welding cannot be completely eliminated, which can easily cause material damage and cause parts to bend or break; while brush plating is coated The thickness of the layer is limited, and it is easy to peel off. Moreover, the above two methods use metal to repair the metal, which cannot change the "hard to hard" cooperation relationship. Under the combined effect of various forces, it will still cause wear and tear.

Polymer material repair elevator failure

In response to the above problems, European and American companies mainly use polymer composite repair methods. Among them, the most mature application is the American Fu Shilan technology system. The polymer material has super strong adhesion, excellent comprehensive mechanical properties, and can be removed without machining. There is no effect of welding thermal stress, and the repair thickness is not limited. At the same time, the metal material of the product does not have the concession, which can absorb the shock vibration of the elevator, avoid the possibility of re-wear, and greatly extend the service life of equipment components Save a lot of downtime for enterprises and create great economic value. ^[1]

Hoist analysis and solution

1. An abnormal sound occurs when the hoist is running

(1) The bottom plate of the bucket elevator meets the chain bucket, adjust the tension device of the base to make the chain tension.

(2) The keys of the transmission shaft and the driven shaft are loose, the sprocket is displaced, and the chain bucket collides with the casing. Adjust the sprocket position and tighten the keys.

(3) The guide plate collides with the chain bucket to trim the position of the guide plate.

(4) The material is sandwiched between the guide plate and the chain bucket, and the material of the enlarged base part is thrown into the corner.

(5) The bearing fails and cannot be operated flexibly. The bearing should be replaced.

(6) Blocks or other foreign objects are stuck in the housing of the machine base. Stop the machine to clear the foreign objects.

(7) The tooth profile of the sprocket (drive, driven sprocket) is not correct. Correct the sprocket profile or replace the sprocket.

(8) The gear sprocket is out of gear with the chain, and the tooth profile of the drive sprocket is corrected.

(9) The drive chain is idling and adjust the chain length.

(10) The casing is not installed properly, and the verticality of the entire length of the casing is adjusted.

2.Vibration of hoist motor base

(1) The motor itself rotates badly, remove the rotor to check the static balance.

(2) The installation precision of the reducer and the motor is poor, and the alignment exceeds the specification, and readjustment is required.

(3) The installation accuracy of the motor base is insufficient, and the levelness exceeds the requirements of the specification, and readjustment is required.

(4) There is an error in the installation of the transmission sprocket, which needs to be readjusted.

(5) The tooth profile of the transmission sprocket is bad. Correct the tooth profile.

(6) The tightness of the transmission sprocket is not appropriate, and it should be adjusted again.

3.Lift ash leakage

(1) If the gasket of the full length flange of the cabinet is damaged or missing, replace it with a new gasket, apply sealant, and re-tighten the flange bolts.

(2) The material leaks from the gaps of the machine head and the machine base, and a gasket or a sealant is added.

(3) The height difference of the input materials is too large, which increases the input pressure. It is necessary to change the input method of the materials and increase the buffering device of the input.

4. The improvement cannot reach the design capacity

(1) The material is bonded to the bucket and the slide, and the material is regularly removed according to the degree of bonding.

(2) The capacity of the front mechanical equipment of the hoist is insufficient, resulting in a small amount of input of materials, so that the hoist cannot reach the design capacity. It is necessary to try to improve the production capacity of the front machine,

(3) The lifting speed is slow, and the speed ratio of the transmission sprocket needs to be changed.

(4) The material measurement method is improper, or the measurement is wrong, check the meter, check the proportion of the material, and revise the calculation method.

5.Insufficient discharge of hoist material

(1) The capacity of the mechanical equipment at the rear of the hoist is small, which can block the discharge runner, and increase the production capacity of the mechanical equipment at the rear.

(2) The discharge port slide is too small or the angle of the slide is not suitable. Correct the discharge slide.

(3) The material is stuck in the bucket and slide, and the material needs to be removed regularly.