How to Reduce Vibrating Screen Noise

 By its nature, during the normal operation Vibrating screen only through vibration can achieved sieving, but the vibration is the root cause of the noise and the sound level is high, the sound sources are many and complex. How can we effectively reduce the noise of vibration screen?

Recently, after we conducted a noise test on vibrating screen in multi-point and multi-directional, we found that the noise spectrum shows broadband characteristics of the low-IF, the sound level also increases with the increases of frequency and amplitude. So, we have carried out research involved vibrating screen noise source analysis and noise reduction measures study.

1. First of all after we analysis the main noise source such as screen plate, side plate, vibration exciter bearings and steel springs and etc, therefore we propose the following noise reduction measures:

2. Fastened all parts on the vibrating screen, particularly the screen plate which replacement frequently, to avoid generated additional vibration due to the loosening of individual components;

3. Replace the punching steel screen plate to polyurethane screen plate with the advantage of small elastic modulus, low noise impact or rubber screen plate;

4. In the structure design of screen box you can use plenty of rubber and plastic component, besides you should consider the stiffness of the side plates, use appropriate stiffness to reduce vibration, thereby reducing low frequency noise waves.

5. Use rubber cloth wider spring to replace steel spring to reduce the impact;

6. Equipment the vibration exciter with soft acoustic cover;

7. Between the inner ring and outer bearing damping to be treated, the bearing rolling elements can be made into the hollow interior of the hollow rolling bodies or rolling elements added damping material, which can reduce the vibration and noise of bearing.

Maintenance Notes for Circular Vibrating Screen

1. Always keep the circular vibrating screen working in a clean and sanitary environment.
2. The bearing on both ends of the motor should be lubricated with anti- high temperature lubricating grease, in the first month, please lubricate once a week .
3. Check flange bolts on both sides of motor, the bolts which fix the mesh and the support connecting bolt shouldn’t have loose phenomenon.
4. The circular vibrating screen should be maintained every half year.
A. clean the vibrator and add grease for all lubricating points.
B. check the abrasion condition of screen mesh, if any damage , please maintain and replace timely.

5. The circular vibrating screen should be maintained and repaired every year. 
A. Open the motor terminal box ,check the insulation between the wires and clean the dust.
B. Add grease on all lubricating points.
C. check each part of the circular vibrating screen and abrasion condition of screen mesh, if any damage please maintain and replace timely.
E. After finishing all the work, a trial run is also required. 

Troubleshooting for Gyratory Screen

As one of our main product, gyratory screen has been supplied to many plants all over the world and also enjoys a good reputation because of its superior design and quality. Gyratory screen is widely applicable to chemical, food processing, refractory materials, building materials, activated carbon, food, PVC powder and other fine materials.
However, during the operation, we may meet some problems, here PK Machinery will introduce the breakdown reason and method in detail.

Breakdown	Reason	Solution
V-belt heating up	V-belt looseness Through of belt is broken or the surface is rough	Loose the bolt which fastens the motor, adjust the distance between motor and belt pulley Check and repair the belt pulley
Bearing heating up	The grease is excessive or shortage or the quality is bad Bearing is broken Main shaft bends or the inertial force is not balanced The bearing cup is not compatible with other parts Belt is too tight Overload working for a long time	Change the grease Change bearing Correct the main shaft Change the part which coordinate with the bearing Adjust the tightness of the V-belt Reduce the feeding rate
There is no force for motor	Two phase electricity Circle short for the winding Overload working for a long time	Power on the lost phase electricity to ensure it runs under 3 phases Inspect the motor Keep the screen working under the rated load
Fail to start the motor	Low voltage Electrical wiring is too thin Fuse is broken	Start the screen once electricity is normal Change the electrical wiring Change a proper fuse
Violent or wiggly vibration	The rotation shaft bends Bearing is broken	Replace or correct the shaft Replace the bearing
The unqualified size material mixed in the finished material	Screen mesh is broken Screen cover or seal bar is loose	Renew the screen mesh Press the cover and seal bar
Capacity declining	The moisture is too high, block the mesh The opening size is not suitable Rotation speed is low or the V-belt is loose Feeding rate is low The rubber ball is worn out	Reduce the moisture of material Renew the screen mesh Check the belt pulley and the tightness of belt Increase the feeding rate Renew the feeding rate

Several motion trajectory of vibrating screen

 The power source of vibration screening equipment -vibration motor can produce round, oval, straight, complex mode of motion.

  Vibration screen has been using vibration motor as power, which is simple and reliable and effective. Vibration motor vibration body in different installation form of combination, can produce different vibration trajectory, so as to effectively accomplish tasks.

   Linear vibrating screen: vibration body (vibration box body and material) projection of the vibration trajectory in horizontal and vertical surface are on the line, the vibration form called linear vibration. This type of vibration sieve is called linear vibrating screen or line screen. The vibration motor two sets of the same type installed in the machine body, so that the two vibration motor shaft are parallel to each other's position, running to the contrary, so running with synchronization, the body produces linear vibration.

  Circular or elliptical vibration: vibration trajectory of the vibrating body projection in the horizontal plane is a straight line, and the projection in a vertical plane is a circle or an ellipse, the vibration form known as round or elliptic vibration. Usually a vibration motor is arranged on the mechanical vibration’ body, can produce this movement. Circular or elliptical vibration occurred in the plane perpendicular to the rotating shaft of the motor on the vibration phase, the form is depand on the vibrating motor and the relative position of center of gravity.

  Composite vibration: the vibration of the vibrating body is generated by the two groups of vibration system, the vibration form is known as the compound vibration. In general there are two kinds of forms, which are dual compound and twin composite type . Vibration screening equipment to certain special properties, the use of two different models of different speed vibration motor, packed in sieving equipment receiving end and a discharge end, so that the vibration by feeding end show large amplitude and low frequency, and the discharge end presents the vibration of high frequency and small amplitude, central overlap two vibration screening equipment the screening equipment, play a screening role in high effects.

  Rotary vibration is also known as three dimensional vibrations : vibration trajectory of the vibrating body projected on the horizontal plane is a circle or an ellipse, the vibration form known as the rotary vibration. This kind of vibration sieve was known as the rotary vibration sieve. Rotary vibration can be divided into flat rotary vibration, vortex type vibration and rotary type vibration in three forms. Projection vibration trajectory when the vibration body in a vertical plane is a horizontal line, the vibration form known as the swing type vibrating; Projection when the vibration body trajectory in a vertical plane is an inclined line, the vibration form known as the vortex vibration. Projection vibration trajectory when the vibration body in a vertical plane is a circle or an ellipse, the vibration form known as the rotary type vibration

  Usually produce rotary vibration by vibration equipment of vertical vibration motor excitation, the vibration form is depend on vertical vibration motor excitation at both ends of the fixed block angle. Two foot mounting type vibration motors can also be installed in two sides of vibration equipment, and the rotating shaft in a set angle, vibration equipment will also produce rotary vibration.

What should We Note during the Operation of Gyratory Screen

Gyratory screen is similar to rotex screener, it is designed with gyratory motion which can obvious improves the distribution of the material. Applicable material includes urea, potash, fertilizer, activated carbon, pellet, ceramic powder, sugar, salt, starch and fireproofing material etc. Here PK Machinery will introduce necessary notes before starting up the screen.

1. Check the fastened part, safe protection device and lubrication before start-up.
2. Test run without load first for about 3-5mins to see if the rotation direction meets the requirement.
3. Feeding material with normal operation once non-load test run is normal,
4. Check the material discharging condition during running, if any blockage is found, please solve it timely.
5. Check the material distribution on screen mesh is uniform or not, if necessary, stop machine and adjust.
6. If there is abnormal noise or vibration that you have to stop the gyratory screen, please stop machine at once, only when the trouble is eliminated, then you can start up.
7. If gyratory screen is operated in a production line together with other equipment, please start up downstream equipment, then start up the upstream equipment.

Vibrating Feeder

Introduction:

Vibrating Feeder is a kind of feeding equipment that can bring bulk, granular and powdery materials from the warehouse or funnel to the receiving equipment continuously or quantitatively in the production process. It can stepless adjust feeding amount and realize the centralized control and automatic control. It can feed material for belt conveyor, bucket elevator, vibrating machinery, crusher, pulverizer etc.

Application :

Vibrating Feeder can be widely used in crushing and screening equipment of metallurgy, coal, mineral separation, construction materials, chemical industry, abrasive and other industries.

Advantages:

1. High efficiency, low operating costs

Vibrating Feeder has high efficiency because its amplitude is stable enough to ensure the liquidity of vibration materials so that can reduce the channel blockage phenomenon. Its structure is simple. Therefore, there are little vulnerable parts. Also, it can save more energy because the power consumption is very low. 

2. High adaptability, low investment

Vibrating Feeder has high adaptability that can work at dusty or moist environment. And the volume is small, the weight is light. Also, the cost performance is high because less investment can gain more.

3.Low noise, little pollution

The noise of machine is low. Through the closed structure,it can prevent dust pollution.

What is the Impact on Adjusting Vibration Motors Inclined Angle of Linear Vibrating Screen

Linear vibrating screen utilizes vibration motors as vibration power driving the material jump up on screen mesh and do linear movement. Besides, concerning the materials like crushed stone and sintered ore which are difficult to sieve, you can change the material residence time by adjusting the inclination angle of vibration motors according to the production requirements to achieve the purpose of higher screening performance, however, what should we do to adjust the vibration motors according to the needs? Today PK Machinery will introduce the impact on adjusting the motors inclined angle of linear vibrating screen:

1.When the vibration motors’s inclined angle is increased 
the horizontal stress of the materials on the screen will be decreased, the forward speed of the material will be decreased , the exciting force on the screen will be decreased, and all of these conditions will result in low screening efficiency and affect the screening effect. 

2.When the vibration motors’s inclined angle is decreased
the horizontal stress of the materials on the screen will be increased, the forward speed of the material will be increased as well . Although this can achieve in high screening efficiency, but it cannot achieve in good screening effect.

After few times of research work and lab testing by PK machinery’s engineer, the most efficient inclination angle of thevibration motors is at angle of 45 degrees which can make the vibration motors work in best performance by giving out high screening effect and efficiency.

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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.

The problem of vibration damping of vibration sieve

   Damping vibration sieve, the key lies in the generator is fixed on the damping.

  Energy saving unit with built-in shock absorber is through with the seismic performance of the rubber shock absorber and steel chassis isolation, so unless the occasions with high requirements to be increased again in isolation device between the steel chassis and the foundation,  allow the steel frame and foundation for direct installation

    For a fixed set of non energy saving built-in shock absorbers must isolation device is additionally arranged between the steel frame and foundation for shock absorber.

     Vibration and noise of shock absorber installation can reduce the ground based, there are several different shock absorbers, The spring shock absorber damping effect is best, the isolation efficiency is up to 98%; glass fiber absorber efficiency is 75% ~ 85%;   Rubber shock absorber is 50% ~ 80%. For the geological and environmental special shockproof requirements, The foundation shall be arranged around the width of 25 ~ 30mm is arranged at the bottom of the isolation trench, base isolation layer, then the foundation bottom ramming, withcement,cinder,asphalt paving thickness of about 200mm, and then concrete is poured on the isolation layer.

  Generator shall anchor bolts with M18 diameter steel frame is fixed to the ground, to prevent movement.

    In addition, generating around the unit must set aside sufficient maintenance space, at the end of the outer periphery of cooling water tank, require the distance with the room wall of not less than 1.5m, the height from the top of the unit room roof height distance shall be not less than 1.5m,usually require a real high low voltage 4.5m, this is the minimum distance that must hold for ventilation and heat dissipation and maintenance unit lifting machine. The base station from the ground at least 150mm.

Application Analysis of Calcium Carbonate Rotary Vibrating Screen

The sealing performance of calcium carbonate rotary vibrating screen is pretty good, non-blocking design and precise screening. Besides, you can also choose ultrasonic vibrating screen instead of common rotary vibrating screen in order to achieve more accurate screening performance, the screening accuracy even can reach 500 mesh.

 In the process of production of calcium carbonate, it mainly includes light calcium carbonate and heavy calcium carbonate, the production process of two kinds of calcium carbonate is the same during crushing and screening. When screening the calcium carbonate, the output rate is designed according to manufacturing production rate per hour, the screening amount is calculated as per the material amount after crushing, the general selection of material granularity is around 100 mesh and the main selection specification is 60 mesh, 80 mesh and 120 mesh etc. In addition, the mesh size is also selected according to the needs of users. In the process of screening, rotary vibrating screen is the best screening equipment, the screen mesh can be replaced with the previous required mesh size in order to achieve the screening requirements.

How to solve Vibrating Screen tripping problem

The tripping problem usually occurs during the vibrating screen operation the generally reason is the electric problem. In this article, for the vibrating screen tripping problem we summarizes some common cause and solutions.

1, Check whether the air switches over current protection capacity inconsistent or aging, if existence, you should repair or replace the air switch directly;

2, Check whether the bearing of vibrating screen or vibrating motor damaged, lack of lubricants etc, this problem will lead to overload then result in tripping;

3, Check whether the cable exists sheel phenomenon;

4. Check whether the device power has problem;

5. Check whether the breaker aging or damaged;          6. The vibration motor magnetic circuit performance degradation can lead to current excessively then causing tripping.

Applicable Scope and Maintenance of Trommel Screen

 Application Scope:

1, used in stones classification used in quarry, and isolated mud and stone powder.

2, used in quarry and sand separation.

3, for lump coal and pulverized coal separation in coal industry and coal washing (part of coal washing machinery).

4, used in the size of the block classification and separation of powder material in chemical industry and mineral processing industry.

Maintenance:

Cage drum screen is reliable operation and less maintenance, some problems that should be paid attention to in the operation are as follows.

1, must open the cage when driving drum screen, and then open the feeding device. When parking on the contrary.

2, in the first three days when operating, check cage trommel fasteners every day, such as loose should be tighten. Later can regularly (weekly or half moon) inspection on cage trommel fasteners.

3, the lubrication condition of bearing, transmission should be checked regularly, and change gas and oil in time. Large shaft bearing adopts 2 lithium grease, under normal circumstances, filling grease once two months, and the volume should not be too much, otherwise it is easy to make bearing overheating.The bearing should be checked once a year.

4, when the equipment is rebooted after long-term outage (30 days or more), wave measurement should be made for the motor insulation to prevent motor burn down.