How to maintain a welding rotator

Maintaining a welding rotator (also known as a turning roll or pipe rotator) is crucial for its longevity, safe operation, and consistent performance. Proper maintenance helps prevent breakdowns, ensures accurate rotation, and protects your investment.

Welding Rotators Maintenance

welding rotator

I. Seguridad ante todo!

Lockout/Tagout (Corazón): Before any maintenance, ensure the rotator is completely de-energized and locked out/tagged out to prevent accidental startup.

Equipo de protección personal (EPP): Wear appropriate PPE, como gafas de seguridad, guantes, and steel-toed boots.

Stable Load: Ensure any workpiece is removed or securely supported before performing maintenance that could affect its stability.

Manufacturer’s Manual: Always consult the specific manufacturer’s manual for your model. This guide is general; your manual will have model-specific instructions and recommendations.

II. Regular Maintenance Schedule & Checklist

UNA. A diario / Before Each Use:

Visual Inspection:

General Cleanliness: Check for excessive dirt, grease, weld spatter, o escombros. Clean as needed.

Rodillos (Drive & Idler): Inspeccionar por daños, tener puesto, flat spots, or embedded foreign objects (slag, virutas de metal). Clean roller surfaces.

Cables & Hoses: Check power cables, control pendant cables, and any hydraulic/pneumatic lines for cuts, frays, kinks, or wear. Ensure they are not tripping hazards.

Control Panel/Pendant: Check for damage. Ensure all buttons, interruptores, and E-stops are functional and not sticking.

Guards & Caracteristicas de seguridad: Verify all safety guards are in place and secure. Test the E-stop function.

Leaks: Look for any oil or grease leaks from gearboxes, aspectos, or hydraulic systems.

Functional Check:

Smooth Operation: Briefly run the rotator (unloaded or with a light test piece) to check for smooth rotation, unusual noises (molienda, whining, clicking), or excessive vibration.

Speed Control: Verify that speed adjustments work correctly.

segundo. Weekly Maintenance:

Thorough Cleaning:

Clean weld spatter and debris from rollers, marco, and drive components. Use a wire brush, scraper (carefully to avoid damaging rollers), or appropriate cleaning agents.

…

For more detailed information on welding rotator maintenance click to visit: https://www.bota-weld.com/en/a/news/welding-rotator-maintenance.html

/por

What are the types of welding column booms?

Welding column and booms (También conocidos como manipuladores de soldadura.) are versatile pieces of equipment used to automate and improve the efficiency and quality of welding, especially for long, circumferential, or repetitive welds on large workpieces. They primarily differ based on their mobility, size/capacity, and sometimes the degree of articulation or control.

Welding Column Booms Types

Welding Column Booms

Fixed Type (Stationary):

Descripción: The base of the column is bolted directly to the workshop floor or a heavy foundation.

Use Case: Ideal for dedicated welding stations where the workpiece is brought to the manipulator. Often used for repetitive tasks on similar-sized components.

Pros: Very stable, takes up a defined footprint.

Cons: Lacks mobility; workpiece positioning is critical.

Movable Type (Free-Standing / Portable):

Descripción: The column is mounted on a heavy base equipped with casters or wheels, allowing it to be moved around the workshop. It might be moved manually or have a simple motorized drive for positioning.

Use Case: Offers flexibility to move the manipulator to different workpieces or work areas within a bay.

Pros: More versatile than fixed types for varied job locations.

Cons: May require leveling or outriggers for stability during operation, especially for larger models.

Track/Rail Mounted Type (Travel Car Type):

Descripción: The column and boom assembly is mounted on a motorized carriage that runs on precisely laid rails or tracks on the floor.

Use Case: Essential for welding very long longitudinal seams on items like large pipes, tanques, vigas, or ship hulls. The manipulator travels along the length of the workpiece.

Pros: Accurate linear movement over long distances, high productivity for long welds.

Cons: Requires dedicated track installation, less flexible for non-linear work.

Size/Capacity Based Classifications (often overlaps with the above):

Welding Column Booms

Light-Duty:

Shorter boom reach (p.ej., up to 2-3 metros).

Lower payload capacity (for lighter welding heads and accessories).

…

For more detailed information on the welding column booms types click to visit: https://www.bota-weld.com/en/a/news/welding-column-booms-types.html

/por

How to Repair Welding Manipulator

Welding manipulators are essential pieces of equipment in automated and semi-automated welding operations, designed to provide precise control over welding torches for consistent and high-quality welds. Sin embargo, like all industrial machinery, welding manipulators are subject to wear, mechanical failures, and electrical issues over time. Knowing how to diagnose and repair a welding manipulator is crucial for maintaining production efficiency, ensuring workplace safety, and minimizing downtime.

Repairing a welding manipulator involves diagnosing common mechanical, electrical, and welding-related issues.

Welding Manipulator Repair

Welding manipulators

1. Identificar el problema

Before starting repairs, observe symptoms to narrow down the issue:

Problemas mecánicos: Jerky movement, desalineación, excessive vibration, or unusual noises.

Problemas eléctricos: Fallo de alimentación, motor not responding, or erratic control behavior.

Welding Issues: Poor arc stability, inconsistent wire feed, or irregular torch movement.

2. Common Repairs & Soluciones

UNA. Mechanical Repairs

Check Rails & Guides

Issue: Misalignment or wear causing jerky movement.

y las razones deben ser investigadas y tratadas a tiempo para resolver:

Clean and lubricate linear guides.

Adjust or replace worn-out rails/bearings.

Inspect Drive Mechanism

Issue: Faulty gears, cinturones, or chains.

y las razones deben ser investigadas y tratadas a tiempo para resolver:

Tighten or replace loose/damaged belts/chains.

Grease gears or replace if teeth are worn.

Column & Boom Stability

Issue: Excessive vibration or wobbling.

y las razones deben ser investigadas y tratadas a tiempo para resolver:

Tighten bolts and structural joints.

Check for cracks in the boom and repair with welding if needed.

segundo. Electrical & Motor Repairs

Motor Not Running

a saber, inspección previa a la producción y embalaje:

Power supply (fuses, breakers, voltage).

Motor brushes (for DC motors) or windings (for AC motors).

…

 

/por

Gantry welding machine working principle in detail: how to achieve 0.1mm welding precision?

Gantry welding machines are specialized automated welding systems designed for high-precision, large-scale welding applications, particularmente en industrias como la construcción naval, structural steel fabrication, and heavy machinery manufacturing. A gantry welding machine operates on a principle of automated movement and precise control of the welding head over a workpiece.

Gantry welding machine working principle and how to achieve 0.1mm welding precision

Gantry welding machines

Gantry Welding Machines Working Principle

Gantry Structure: The machine features an overhead bridge-like structure (the gantry) that spans the welding area. This gantry provides a stable and rigid framework for the welding process.

Multi-Axis Movement: A carriage or trolley carrying the welding head moves along the gantry (typically the X-axis). The gantry itself can also move along rails (the Y-axis), and the welding head often has vertical movement (the Z-axis). This multi-axis movement allows the welding head to reach any point within the machine’s working envelope.

Automated Control System: The movement of the gantry and the welding head is controlled by a sophisticated numerical control (CNC) system or a programmable logic controller (PLC). This system directs servo motors that drive the movement along each axis with high precision.

Welding Process Integration: The gantry system is integrated with various welding power sources and equipment (p.ej., Soldadura de arco sumergido (SIERRA), Gas inerte metálico (A MÍ), Metal Active Gas (MAG)). The control system also manages the welding parameters such as voltage, actual, wire feed speed, and travel speed.

Seam Tracking (Optional but crucial for precision): Advanced gantry welding machines often incorporate seam tracking systems. These systems use sensors (p.ej., mecánica, laser, vision) to detect the actual weld joint in real-time and automatically adjust the welding head position to follow the seam accurately, even if the workpiece has slight variations or distortions.

Material Handling: While not directly part of the welding principle, gantry machines are often integrated with material handling systems (p.ej., transportadores, positioners) to move and orient the workpiece efficiently.

Achieving 0.1mm Welding Precision

Gantry welding machines

Achieving such high welding precision (0.1mm) requires a combination of advanced technologies and meticulous engineering:

High-Precision Motion Control System:

High-Resolution Encoders: Servo motors on each axis must be equipped with high-resolution encoders to provide precise feedback on the welding head’s position.

This allows the control system to make minute adjustments to ensure accuracy.

…

More detailed information about the working principle of the gantry welding machine can be clicked to visit: https://www.bota-weld.com/en/a/news/gantry-welding-machine-working-principle.html

/por

How to choose a ball press machine for briquettes?

Elegir lo correcto máquina de prensa de bolas is a critical step in setting up an efficient and profitable briquette production line. Whether you’re working with coal powder, metal fines, polvo de carbón, or mineral residues, selecting a machine that fits your raw materials, capacidad de producción, and budget will directly impact the quality and strength of your briquettes. En esta guía, we’ll walk you through the key factors to consider when buying a ball press machine.

Ball Press Machine for Briquettes Selection

ball press machine

1. Raw Material Compatibility

The type of raw material you’ll be briquetting is paramount. Different machines are designed for specific materials and their characteristics (contenido de humedad, particle size, binding properties).

Common Materials:

Biomass: Serrín, astillas de madera, residuos agrícolas (paja, rice husks, bagasse, coffee husks, peanut shells), bamboo.

Coal/Charcoal: Coal powder, polvo de carbón, coke dust, lignite, anthracite.

Minerals/Ores: Iron powder, polvo mineral, oxidized scale, slag, gypsum, tailings, lodo, kaolin, activated carbon, metal fines.

Otros: Quicklime powder, magnesium powder, materiales refractarios, materiales cerámicos.

Consideraciones:

Particle Size: Most ball press machines require the raw material to be finely ground (often less than 3mm, with a significant percentage below 1mm) for optimal briquette formation and strength. You may need a grinder or hammer mill as a pre-processing step.

Contenido de humedad: The ideal moisture content varies by material and machine, but it’s often around 8-10% for charcoal/coal and can be higher for some biomass.

Too much or too little moisture can significantly impact briquette quality.

2. Capacidad de producción

Determine your desired output. This will dictate the size and power of the machine you need.

Factors:

Amount of raw material available.

Required briquette output per hour/day (p.ej., 1-2.5 t/h, 3-5 t/h, 5-8 t/h, up to 28 t/h for larger models).

Operating hours (single shift, continuous operation).

Calculation: For a basic estimation, consider the density of your briquettes and the volume they occupy, then factor in the machine’s efficiency and the time available for production.

3. Briquette Size and Shape

Ball press machines typically produce briquettes in various shapes, incluyendo:

…

More details about how to choose briquette press machine can be clicked to visit: https://www.zymining.com/en/a/news/ball-press-machine-for-briquettes-selection.html

/por

What are the reasons for the large vibration of the hammer crusher?

trituradoras de martillo are widely used in mining, cemento, metalurgia, and aggregate industries for crushing medium-hard materials such as limestone, carbón, and gypsum. Sin embargo, abnormal vibration during operation is a common issue that can severely impact machine performance and lifespan.Large vibrations in a hammer crusher are a common problem and can lead to premature wear, component failure, reduced efficiency, and safety hazards.

Reasons for Large Vibration of Hammer Crusher

hammer crusher

Rotor Imbalance (Most Common Cause):

Uneven Hammer Wear: Hammers wear down at different rates depending on their position and the feed material. If not managed, this creates a significant weight imbalance.

Incorrect Hammer Replacement: Replacing hammers with ones of different weights, or replacing only some hammers without balancing, will cause imbalance.

Hammers should always be replaced in sets (opposite pairs or full sets) and be weight-matched.

Broken or Missing Hammers/Pins: A broken hammer or a lost hammer pin will immediately create a severe imbalance.

Acumulación de materiales: Sticky or wet material can build up unevenly on the rotor, martillos, or inside the rotor discs, adding weight to one side.

Bent Rotor Shaft: A bent shaft will cause the entire rotor assembly to wobble.

Rotor Disc Deformation: If the discs holding the hammers are bent or damaged.

Bearing Issues:

Rodamientos desgastados o dañados: Worn bearings develop excessive clearance (play), allowing the shaft to move erratically, leading to vibration. Damaged races or rolling elements also cause rough running.

Incorrect Bearing Lubrication: Too little, too much, or the wrong type of lubricant can cause bearings to overheat and fail.

Misaligned Bearing Housings: If the bearing housings are not perfectly aligned, they put undue stress on the bearings and shaft.

Loose Components:

Loose Foundation Bolts: If the crusher is not securely anchored to its foundation, it will vibrate excessively.

Loose Rotor Mounting Bolts: Bolts connecting the rotor to the shaft or bearing assemblies.

Loose Hammer Pins/Bolts: If hammer pins are loose, hammers can shift, contributing to imbalance and impact forces.

Loose Liner Plates or Grate Bars: Can vibrate independently or cause material to jam.

Operational Issues:

Overfeeding: Feeding too much material at once can choke the crusher, leading to uneven loads and vibration.

Feeding Uncrushable Material: Introducing tramp metal or excessively hard material can cause sudden shocks and damage, leading to vibrations.

…

More detailed information about the causes of high vibration of hammer crusher can be clicked to visit: https://www.zymining.com/en/a/news/reasons-for-large-vibration-of-hammer-crusher.html

/por

What are the applications of a ball press machine?

UNA máquina de prensa de bolas, more commonly known as a briquetting machine or briquetter, is used to compress powdery or granular materials into solid, uniform shapes (briquettes), often resembling balls, pillows, ovals, or squares. This process offers several advantages like improved handling, almacenamiento, transporte, and utilization of fine materials.

Ball Press Machine Application

ball press machine

Metallurgical Industry:

Steelmaking: Briquetting iron ore fines, mill scale, converter dust, flue dust, and other iron-bearing materials for charging into blast furnaces or direct reduction plants. This recovers valuable materials and improves furnace operation.

Ferroalloy Production: Briquetting fines of manganese ore, chrome ore, nickel ore, etc., for smelting furnaces.

Non-Ferrous Metals: Briquetting dusts and fines from copper, zinc, lead, and aluminum processing for recycling and smelting.

Lime and Dolomite: Briquetting quicklime or dolomite fines for use as flux in steelmaking, reducing dust and improving handling.

Carbón & Energy Industry:

Coal Briquetting: Compressing coal fines or dust into briquettes for industrial boilers, gasifiers, or domestic heating. This utilizes low-grade coal fines and reduces waste.

Coke Briquetting: Briquetting coke breeze (fine coke particles) for use in foundries or blast furnaces, recovering valuable fuel/reductant.

Charcoal Briquetting: Compressing charcoal powder (often with a binder) into briquettes for barbecue, industrial heating, or activated carbon production.

ball press machine

Químico & Mineral Industry:

Fertilizantes: While granulation is common, briquetting can sometimes be used for specific fertilizer materials or formulations to reduce dust and improve handling.

Salt Briquetting: Producing salt blocks or briquettes for animal licks or industrial applications.

Mineral Processing: Briquetting various mineral fines (p.ej., fluorite, magnesite, bauxita) for easier handling, transporte, or feeding into subsequent processes like kilns or furnaces.

Refractory Materials: Briquetting fine refractory powders before firing.

Environmental Protection & Waste Recycling:

Flue Gas Desulfurization (FGD) Gypsum: Briquetting FGD gypsum powder, a byproduct of coal-fired power plants, for easier handling and potential use in construction materials (p.ej., cement production).

…

More detailed information about the application of ball press can be clicked to visit: https://www.zymining.com/en/a/news/ball-press-machine-applications.html

/por

What should I do if the briquette machine jams?

Briquetadoras are essential in compressing various raw materials into compact, manageable briquettes for easier storage, transporte, and usage. Sin embargo, one common operational challenge is machine jamming. A jammed briquetting machine can disrupt production, cause equipment damage, and increase maintenance costs. Understanding the root causes of jamming, the warning signs, and effective prevention strategies is crucial for maintaining smooth and efficient briquetting operations.

What should I do if the briquette machine jams

Briquetting machines

1. Immediate Safety Measures:

Stop the Machine: Immediately turn off the power to the briquette machine. Do not attempt to clear the jam while the machine is running.

Desconectar la potencia: For added safety, unplug the machine from its power source. This prevents any accidental start-up during the clearing process.

Wait for it to Stop Completely: Ensure all moving parts have come to a complete standstill before attempting to intervene.

2. Identify the Cause of the Jam:

Carefully inspect the machine to understand why it has jammed. Las causas comunes incluyen:

Bloqueo de material:

Oversized Material: Pieces of raw material that are too large to pass through the machine.

Foreign Objects: Rocks, metal pieces, or other debris mixed in with the raw material.

Wet or Sticky Material: Material with excessive moisture content or a sticky consistency can clump and cause blockages.

Inconsistent Material Size: A wide range of particle sizes can sometimes lead to bridging and jams.

Machine Issues:

Worn or Damaged Parts: A worn die, tornillo transportador, or other internal components can impede material flow.

Improper Temperature: If the machine uses heat, incorrect temperature settings can affect material flow and cause sticking.

Lubricación insuficiente: Lack of lubrication can increase friction and lead to jams.

Overfeeding: Trying to process too much material at once can overload the machine.

Briquetting machines

3. How to Clear the Jam:

Refer to Your Machine’s Manual: Your briquette machine’s manual should provide specific instructions on how to clear jams and troubleshoot common issues. Always prioritize the manufacturer’s recommendations.

…

More detailed information about what to do when the briquette machine is stuck can be clicked to visit the: https://www.zymining.com/en/a/news/briquetting-machine-jam.html

/por

Qué materiales se pueden seleccionar con una pantalla vibratoria lineal

Cribas vibratorias lineales are highly versatile and can be used to screen a wide range of materials across various industries. La clave es que el material debe poder fluir y separarse en función del tamaño cuando se somete a vibración lineal.

La pantalla de vibración lineal puede la pantalla de los materiales

Tamiz de plátano doble

1. Minería & canteras:

* Minerales: Mineral de hierro, mineral de cobre, mineral de oro, bauxita, mineral de manganeso, etc. (para dimensionar, escala, deslimar)

* Carbón: Apresto, deshidratación, deslimar

* Agregados: Arena, grava, piedra triturada (para dimensionar en diferentes calificaciones de productos)

* Caliza, Granito, Basalto: Para producir varios materiales de construcción

* Roca de fosfato, Potasa: Para la producción de fertilizantes

* Minerales industriales: Arcilla, arena de sílice, feldespato, talco

2. Construcción & Materiales de construcción:

* Arena & Grava: Calificación para concreto y asfalto

* Piedra triturada: Dimensionamiento para la base de la carretera, agregado de concreto

* Materias primas de cemento: (p.ej., caliza, arcilla antes de moler)

* Asfalto reclamar (RAP): Dimensionamiento de asfalto recuperado

* Agregados livianos: Arcilla expandida, esquisto, perlita

3. Reciclaje & Gestión de residuos:

* Construcción & Demolición (do&re) Desperdiciar: Separar el suelo, agregados, la madera, plástica

* Residuos sólidos municipales (MSW): Pre-sorte, Separar orgánicos

* Compost & Suelo: Eliminar partículas de gran tamaño, contaminantes

* Cullet de vidrio: Dimensionamiento de reciclaje

* Copos de plástico/pellets: Apresto, eliminando multas

* Chips de madera, Serrín, Ladrar: Dimensionamiento de combustible, mantillo, o tablero de partículas

* Chatarra: Eliminar la suciedad y las multas

4. Agricultura & Procesamiento de alimentos:

* Granos: Trigo, maíz, arroz, cebada, avena (limpieza, apresto)

* Semillas: Dimensionamiento y limpieza de varias semillas de cultivo

* Fertilizantes: Granular o en polvo (apresto, desesperado)

* Alimento para animales: Bandear, muescas (apresto, eliminando multas)

* Azúcar, Sal: Apresto, de iluminación

* Harina, Especias, Granos de café, Hojas de té: Cernido, calificación

* Cojones & Legumbres: Apresto, eliminar conchas o escombros

* Frutas & Verduras (a veces): Para dimensionar o deshidrates suaves de ciertos tipos robustos

Tamiz horizontal de una sola capa

5. Químico & Industrias farmacéuticas:

* Pellets de plástico & Polvos: Apresto, desesperado

* Resinas: Apresto

* Polvos detergentes: Apresto, de iluminación

* Polvos farmacéuticos & Gránulos: (a menudo especializado, diseños higiénicos)

* Varias sales químicas & Compuestos: (p.ej., ceniza de soda, catalizadores)

…

La información más detallada sobre qué materiales se pueden seleccionar mediante una pantalla de vibración lineal se puede hacer clic para visitar: https://www.hsd-industry.com/news/linear-vibrating-screen-can-screen-materials/

/por

Qué hacer si la pantalla vibratoria lineal se descarga lentamente? Explicación detallada de los motivos y soluciones.

Slow discharge from a criba vibratoria lineal is a common issue that can significantly reduce screening efficiency and overall plant productivity. Significa que el material no se mueve a través y fuera de la cubierta de la pantalla tan rápido como debería.

Razones y soluciones para la descarga lenta de la pantalla vibratoria lineal

Cliente de cooperación

I. Razones relacionadas con la malla de pantalla & Cubierta:

Cegamiento o fijación de la malla de la pantalla:

pero el producto no responde: Las partículas finas se atasquen en las aberturas de la malla de pantalla (cegador), o las partículas de tamaño cercano se encajan en las aberturas (revestimiento). Esto reduce el área abierta efectiva, ralentizar el paso de material de menor tamaño y hacer que el material de gran tamaño se acumule y descargue lentamente.

y las razones deben ser investigadas y tratadas a tiempo para resolver:

Limpieza periódica: Limpia manualmente la malla con pinceles, arandelas a presión, o lanzas de aire.

Dispositivos anti-Blinding: Instalar bolas de rebote, anillos deslizantes, o estrellas de poliuretano debajo de la malla de la pantalla. Estos tocan continuamente la malla desde abajo, desalojando partículas atascadas.

Sistemas de desinflamiento ultrasónico: Para materiales muy finos o difíciles, Los sistemas ultrasónicos vibran la malla a altas frecuencias, Prevención de cegamiento.

Malla autolimpiada: Use medios de pantalla especializados con cables flexibles que vibren de forma independiente para desalojar partículas.

Ajustar la tensión de la malla: Asegúrese de que la malla esté correctamente tensada. La malla hundida puede exacerbar el cegamiento.

Apertura de malla de pantalla incorrecta (Tamaño de apertura):

pero el producto no responde: Si las aberturas de malla son demasiado pequeñas para la separación deseada o para la mayor parte del material, naturalmente procesará el material lentamente.

y las razones deben ser investigadas y tratadas a tiempo para resolver:

Reevaluar la solicitud: Asegúrese de que el tamaño de la malla elegido sea apropiado para las características del material y el punto de corte deseado.

Considere una malla más gruesa: Si es posible y aceptable para el producto, Use una abertura de malla ligeramente más grande.

Malla de pantalla desgastada o dañada:

pero el producto no responde: Rasgado, estirado, o la malla excesivamente desgastada puede perder su tensión, hundimiento, y tener aperturas inconsistentes. Esto puede conducir a la agrupación de materiales en áreas y una transmisión ineficiente.

y las razones deben ser investigadas y tratadas a tiempo para resolver:

Inspeccionar y reemplazar: Inspeccione regularmente la malla para el desgaste. Reemplace las secciones dañadas o todo el panel de malla según sea necesario.

Área de detección insuficiente:

pero el producto no responde: La pantalla puede ser demasiado pequeña para el volumen de material que se le está alimentando., conduciendo a sobrecargar.

y las razones deben ser investigadas y tratadas a tiempo para resolver:

Reducir la velocidad de alimentación: Si es posible, Reducir la cantidad de material que se alimenta a la pantalla.

Tamaño de pantalla de actualización: Si la velocidad de alimentación no se puede reducir, Puede ser necesaria una pantalla más grande o una pantalla adicional.

Malla de pantalla de caída:

pero el producto no responde: El tensión o desgaste inadecuado puede hacer que la malla se hunde. El material se acumula en las áreas hundidas, ralentizando su progreso.

y las razones deben ser investigadas y tratadas a tiempo para resolver:

Tensión adecuada: Asegúrese de que todos los pernos y mecanismos de tensión se ajusten correctamente de acuerdo con las especificaciones del fabricante.

Barras de apoyo: Compruebe si las barras de soporte debajo de la malla son adecuadas y en buenas condiciones.

II. Razones relacionadas con los parámetros de vibración:

Tamiz de plátano doble

Accidente cerebrovascular incorrecto (Amplitud):

pero el producto no responde: Si el golpe (la distancia que la pantalla se mueve con cada vibración) es demasiado pequeño, El material no se elevará y se lanzará de manera efectiva, Materiales especialmente más gruesos o pesados.

…

Más sobre la descarga de pantalla de vibración lineal, se puede hacer clic en la información fina detallada lenta para visitar: https://www.hsd-industry.com/news/linear-vibrating-screen-discharges-slowly/

/por