Changes brought by submersible pumps to the chemical industry

2025-06-13

#Submersible pumps are core equipment in chemical processes. With their corrosion resistance and efficient transportation, they significantly improve production safety and efficiency. According to global market data in 2024, submersible pumps account for 35% of the chemical industry, of which #fluoroplastic submersible pumps and #stainless steel submersible pumps are the two main types, targeting different working conditions.

1. Fluoroplastic submersible pump

Application areas: strong acid (such as sulfuric acid, hydrochloric acid), strong alkali and organic solvent transportation, commonly used in electroplating, pharmaceuticals, and wastewater treatment.

①Advantages:

Extremely corrosion-resistant, PTFE material can resist 98% of chemical media;

Good sealing performance, reducing the risk of leakage;

Lightweight design, easy installation and maintenance.

②Disadvantages:

Low mechanical strength, poor adaptability to high temperature and high pressure scenes;

Price is higher than ordinary metal pumps (average price is 20%-30% higher).

2. Stainless steel submersible pump

FY series stainless steel submersible pump

Application areas: medium and low corrosive media (such as salt water, weak acid), food processing and petroleum industry.

①Advantages:

Sturdy structure, suitable for high pressure and high temperature environment;

Low cost, market share of about 60%;

High degree of customization (such as 316L stainless steel model).

②Disadvantages:

Insufficient tolerance to highly corrosive media such as hydrofluoric acid;

Long-term use may cause pitting due to chloride ions.

2. The innovative contribution of submersible pumps to the chemical industry

Submersible pumps solve the leakage and efficiency problems of traditional pumps in the transportation of corrosive and high-temperature media through the design of direct immersion in the medium, becoming a key equipment for chemical process upgrades. Its core changes are reflected in two major technical routes:

4. Breakthrough application of fluoroplastic submersible pumps

Corrosion-resistant revolution: Using materials such as PTFE, it can withstand 98% of chemical media (such as hydrofluoric acid and concentrated sulfuric acid), which can extend the equipment life of high-corrosion fields such as electroplating and pharmaceuticals by 3-5 times

Safety upgrade: Magnetic drive technology (such as the Coenco brand) completely eliminates the risk of leakage and meets the explosion-proof requirements for the transportation of flammable and explosive media

5. Adaptability optimization of stainless steel submersible pumps

Cost-effectiveness advantage: It occupies 60% of the market share and is suitable for medium and low corrosion scenarios (such as salt water and weak alkali). It has been expanded to the food processing field through the upgrade of 316L material

High temperature and high pressure adaptation: Sulzer API 610 BB5 pumps achieve stable operation at 300℃ in slurry bed residue oil hydrogenation units

6. Systematic industry impact

Environmental benefits: Wastewater treatment pumps (such as Wilo's 144 submersible mixers) help Zhuyuan Sewage Plant increase its daily processing capacity to 3.4 million m³.

#Vertical Submersible Pump #Chemical Industry Submersible Pump #Fluoroplastic Submersible Pump #Stainless Steel Submersible Pump #Wastewater Treatment Pump #Magnetic Drive Submersible Pump

Corrosion-resistant fluorine-lined centrifugal pump replacement mechanical seal operation guide

2025-06-13

Introduction

#Fluorine-lined centrifugal pumps are widely used in the transportation of highly corrosive media such as sulfuric acid, hydrofluoric acid, and organic solvents due to the excellent corrosion resistance of PTFE/PFA linings. Mechanical seals are core components for leakage prevention, and their replacement quality directly affects the life and safety of the pump. This article takes three typical media, 98% sulfuric acid, 40% hydrofluoric acid, and mixed organic solvents, as examples to explain the key points of operation.

I. General preparations

1. Safety protection

· Wear chemical protective clothing + mask (acidic medium) or organic solvent-resistant gloves (solvents)

· Set up a "maintenance" warning sign and confirm that the power supply is double disconnected

2. Pre-processing

· Close the inlet and outlet valves and drain the residual medium in the pump (sulfuric acid medium needs to be neutralized and rinsed with sodium carbonate solution)

· Use a special fluoroplastic cleaner to wipe the pump cavity to avoid metal tools scratching the lining layer

II. Key points for medium differentiation operation

Case 1: 98% concentrated sulfuric acid medium pump

· Special requirements: The sealing surface must be made of silicon carbide, and graphite rings are prohibited (sulfuric acid will cause graphite expansion and failure)

· Disassembly tips:

① Loosen the middle bolt of the pump cover first to prevent sudden splashing of sulfuric acid crystals

② Check whether the shaft sleeve has pitting caused by sulfuric acid corrosion, and replace it simultaneously if necessary

Case 2: 40% hydrofluoric acid medium pump

· Key steps:

① After disassembly, calcium gluconate gel is needed to neutralize residual fluoride ions

② The static ring must be filled with polytetrafluoroethylene, and the dynamic ring is recommended to be alumina ceramic

Case 3: Acetone/chloroform mixed solvent pump

·Precautions:

① Rubber #O-rings are prohibited, and perfluoroether rubber (FFKM) seals are used instead

② Thoroughly degrease with anhydrous ethanol before installation to prevent the solvent from dissolving the grease and contaminating the sealing surface

III. Standardized process for mechanical seal disassembly

1. Safety preparation stage

·Power off and lock (LOTO), and hang warning signs.

·Close the inlet and outlet valves and drain the medium in the pump (acid medium needs to be neutralized and flushed).

2. Coupling separation

·Remove the protective cover bolts and use the puller tool to disassemble the coupling (cast iron impellers need to be padded with wooden blocks to prevent cracking)

3. Pump body disassembly

·Symmetrically loosen the pump cover bolts and pull out the motor and impeller assembly as a whole.

·Large pump bodies need to use the pump cover screw holes to push out the impeller

4. Removal of seal assembly

·Remove the impeller nut with a socket wrench and pull out the impeller axially (threaded impeller needs to rotate counterclockwise)

·First remove the dynamic ring assembly, and then use non-metallic tools to pry out the static ring (protect the O-ring)

IV. Key steps for mechanical seal installation

1. Pretreatment

·Clean the shaft sleeve, sealing chamber and new seal with acetone

·Check that there are no scratches on the mirror surface of the dynamic and static rings and no deformation of the spring

2. Installation of static ring

·Press the static ring vertically into the sealing chamber to ensure that the anti-rotation pin is in the groove (clearance 0.1-0.2mm)

3. Assembly of dynamic ring

·Apply silicone grease before the dynamic ring assembly is inserted into the shaft, and adjust the spring compression according to the manufacturer's standard

4. Reinstall the whole assembly

·After the impeller is installed, manually turn the wheel to check that there is no friction sound

Tighten the pump cover bolts in diagonal order in batches (torque refers to GB/T 16823.1)

V. High-frequency operation risk tips

·Acid medium pump: HF pump needs to be neutralized with calcium gel after disassembly, and graphite seal is prohibited for sulphuric acid pump

·Solvent pump: FFKM O-ring must be used, and ethanol degreasing must be performed before installation

·Common taboos: It is forbidden to knock on the end face of the static ring, and the dynamic ring should automatically rebound ≥3 times after compression

VI. Test acceptance standards

1. After the point-to-point test is correct, it should run continuously for 30 minutes

2. Leakage control:

·Water medium ≤5 drops/minute

·Corrosive medium ≤3 drops/minute

VII. High-frequency maintenance questions and answers

Q: Why is the double-end face machine seal more recommended for fluorine-lined pumps?

A: Isolation fluid can be added to form a protective barrier, which is especially suitable for permeable media such as hydrofluoric acid

Q: How to deal with vibration exceeding the standard after the machine seal is replaced?

A: First check the dynamic balance of the impeller and the bending of the shaft, and then confirm that the verticality of the static ring installation is ≤0.05mm

In summary, the replacement and maintenance of the mechanical seal of the corrosion-resistant pipeline pump is crucial to ensure the normal operation of the equipment. Users must not only master the correct replacement method, but also carefully follow the relevant precautions to extend the service life of the equipment and improve production efficiency.‌

#PTFE lined centrifugal pump #Corrosion resistant pump seal kit #Fluoroplastic chemical pump #PFA lined pump spare parts #How to replace seal on acid transfer pump #Best mechanical seal for 98% sulfuric acid

Learn more about self-priming pumps key performance and selection guide

2025-06-13

This article aims to introduce the performance of self-priming pumps in more detail and under what working conditions you should choose #self-priming pumps. I hope it will be helpful to you.

1. Comparison between #fluoroplastic self-priming pump and #stainless steel self-priming pump

①. Fluoroplastic self-priming pump

Performance characteristics: Made of PTFE/PP and other materials, resistant to strong acids and alkalis (such as 98% sulfuric acid, 50% hydrofluoric acid)

Applicable working conditions: chemical waste acid treatment, electroplating liquid transportation, corrosive media in the pharmaceutical industry

Advantages: Corrosion resistance far exceeds that of metal pumps, light weight (30% lighter than stainless steel of the same model)

Disadvantages: Upper temperature limit 120℃ (stainless steel can reach 200℃), not resistant to particle wear

②. #Stainless steel self-priming pump (304/316L)

Performance characteristics: high mechanical strength (compressive capacity up to 1.6MPa), can handle media containing trace solid particles

Applicable working conditions: food processing (such as sauce transportation), seawater desalination pretreatment, environmental sewage treatment

Advantages: good structural stability, long maintenance cycle (bearing life is about 8000 hours)

Disadvantages: not resistant to chloride ion corrosion (316L should be used with caution when Cl-＞200ppm)

2. #Fluoroplastic self-priming pump vs #Fluoroplastic centrifugal pump‌

①. Fluoroplastic self-priming pump‌

Through the gas-liquid separation chamber and reflux hole design, it needs to be filled with liquid once before the first start, and then the air in the suction pipeline can be automatically discharged to form a vacuum (the self-priming height is usually 3-4m)

Typical structure: external mixing design, the impeller groove and the volute cooperate to achieve gas-liquid mixing and separation

②. #Fluoroplastic centrifugal pump‌

Relies on the centrifugal force of the impeller to transport liquid, must be completely filled with liquid and exhausted before starting, no self-priming ability

Typical structure: closed impeller + volute flow channel, high requirements for medium purity

③. Key performance comparison

Comparison Items	Fluoroplastic self-priming pump	Fluoroplastic centrifugal pump
Self-priming ability	Can handle media with gas content ≤15%	It needs to be completely exhausted. When the gas content is >5%, it is easy to cavitation.
Startup method	No need to repeat the operation after the first filling	Each start requires filling and exhaust
Efficiency	Lower (about 5-8% lower than centrifugal pump)	Higher (n can reach more than 70%)
Particle resistance	Only suitable for media without solid particles	Can handle media containing trace particles (≤0.1mm)
Installation Requirements	No foot valve required (except for special working conditions)	Need to install bottom valve or vacuum water diversion device

④. Typical application scenarios

Preferred working conditions for fluoroplastic self-priming pumps

Intermittent operation: such as chemical tank truck unloading, electroplating liquid circulation

Large liquid level fluctuations: underground storage tank suction, emergency drainage

Preferred working conditions for fluoroplastic centrifugal pumps

Continuous and stable transportation: pickling production line, pure water circulation system

High head requirements: chemical process pressurization (head can reach more than 80m)

⑤. Selection recommendations

Select self-priming pumps: when the working conditions have frequent start and stop, pipeline gas storage risks or the installation position is higher than the liquid level

Select centrifugal pumps: for scenes that pursue high efficiency, large flow stable transportation and can ensure continuous filling

3. Stainless steel self-priming pumps vs. #Stainless steel centrifugal pump

①.Core differences:

Self-priming ability: The self-priming pump can form a 5m water column vacuum when it is first started (the centrifugal pump needs to be filled with water)

Gas-liquid mixed transmission: The self-priming pump can handle media with a gas content of 15% (the centrifugal pump is limited to 5%)

Efficiency curve: The centrifugal pump is 5-8% more efficient at the rated point, but the self-priming pump is more stable under variable conditions

Installation requirements: The centrifugal pump requires NPSH>3m, and the self-priming pump allows a negative NPSH

②.Selection suggestions:

Select a self-priming pump for frequent start-stop/liquid level fluctuations (such as unloading oil from a tanker truck)

Select a centrifugal pump for large flow and stable conditions (such as fire water supply system)

#self-priming pump for chemical transfer #ZX series self-priming pump #explosion-proof self-priming pump #ZW type sewage self-priming pump #FZB fluoroplastic self-priming pump #high suction lift self-priming pump

What is a Slurry Pump The Complete Guide‌

2025-06-13

Introduction: The Industrial Value of Slurry Pumps‌

Slurry pumps serve as core conveying equipment in industries such as mining, metallurgy, and chemical processing, undertaking the critical task of transporting highly abrasive, high-concentration solid-liquid mixtures. According to 2024 data from the China Heavy Machinery Industry Association, the global slurry pump market has surpassed $5.2 billion, with China accounting for 38% of the market share.

1. Core Knowledge System of Slurry Pumps‌

1.‌1 Basic Definition and Working Principle‌

1）Professional Definition‌: A slurry pump (Slurry Pump) is a centrifugal pump specifically designed for transporting slurries containing solid particles.

2）Working Principle‌: The rotation of the impeller generates centrifugal force, imparting kinetic energy to the solid-liquid mixture (Key parameters: Head 30-150m, Flow rate 10-6000m³/h).

1.2 Comparison of Mainstream Types

‌Project Site‌‌	Company	‌Application Scenario
Phosphoric acid slurry in phosphate fertilizer production	Anhui Changyu Pump And Valve (CHANGYU)	Fluoroplastic slurry pumps, corrosion-resistant horizontal centrifugal pumps.
River dredging	Grundfos	Submersible slurry pumps.
Mine tailings transportation	Shijiazhuang Industrial Pump Factory	Vertical submerged pumps, chemical slurry circulation pumps.
Blast furnace slag treatment in steel plants	Anhui Changyu Pump And Valve (CHANGYU)	High-temperature slurry pumps (with cooling system, heat-resistant alloy steel material such as CD4MCu).

3. Key Performance Indicators‌

1）‌Wear Rate‌: Hard alloy lining with HRC58 or higher

2）‌NPSHr‌: ≤4.5m

3）‌Efficiency‌: Heavy-duty pumps achieve 75-82%

2. Selection Decision Tree‌

2.‌1 Medium Characteristics Analysis‌

‌Particle Size‌: μm-level to mm-level

‌Concentration Range‌: 5%-70% wt

‌pH Value‌: Acidic/Alkaline medium

‌2.2 Operating Condition Matching‌

1）‌98% Concentrated Sulfuric Acid Circulation (80°C)‌: ‌CYF Series (Fluoroplastic-Lined Pump)‌ — ‌CYF80-50-250

2）‌High-Hardness Mineral Slurry (Quartz Sand Tailings, SiO₂ Content >90%)‌: ‌CYH Series (High-Chrome Alloy Pump)‌ — ‌CYH150-400B‌

3）‌Titanium Dioxide Acid Digestion Filtration (20% Sulfuric Acid + Titanium Slag)‌:Fluorine-Lined Filter Press Pump (PTFE Back Ring on Impeller, Outlet with Safety Pressure Relief Valve) — ‌CYF80-65-160

3. Fluoroplastic Slurry Pump Maintenance Instructions‌

3.‌1 Daily Operation Maintenance‌

1） Vibration Monitoring‌

Daily inspection of bearing vibration value (should be ≤4.5mm/s)

Abnormal vibration requires immediate impeller balance check

2） Sealing System Management‌

Mechanical seal flush water pressure must be maintained ‌0.1-0.2MPa higher‌ than pump chamber pressure

Weekly inspection of seal leakage (normal ≤5 drops/minute)

3.‌2 Periodic Maintenance Standards‌

1） Flow-Part Inspection‌

Measure fluoroplastic lining thickness every ‌500 hours‌ (wear allowance ≥3mm)

Impeller and wear ring clearance should be ‌0.5-1.0mm‌

2） Lubrication System‌

Bearings: Replace grease every ‌2000 hours‌ (recommended ‌PTFE-based grease‌)

Motor bearings: Annual cleaning and oil change

3.3 Special Condition Handling‌

1）Crystalline Medium Treatment‌

Flush pump chamber with clean water after shutdown (especially when handling crystallizing media)

For long-term shutdowns, drain residual liquid and perform drying treatment

‌2）Temperature Control‌

Monitor lining thermal deformation when medium temperature ‌>80°C‌

Avoid sudden cooling/heating (‌ #heavy duty slurry pump #industrial slurry pump #mining slurry pump #best pump for slurry #electric submersible slurry pump #diaphragm slurry pump

Banana screen

2025-06-13

Banana (Multi-slope) screens have become widely used in high-tonnage sizing applications
where both efficiency and capacity are important.
Banana screens typically have a variable slope of around 24°-45° at the feed end of the screen, reducing to around 0°-8° at the discharge end of the screen. Banana screens are

usually designed with a linear motion/stroke vibrator.

Stage 1: High velocity
The feed section (highly inclined) of a banana screen causes high velocity material flow
which serves to quickly remove fine material.
Stage 2: Medium velocity
Midway along a banana screen, the resultant thinner bed stratifies quickly. The remaining
fine material (below the cut point) is screened out more effectively than would be possible on
a slower thicker bed.
Stage 3: Low velocity discharge
The lower screen slope slows the material down. More efficient screening of near size material occurs here.
As shown in above figure, the steep sections of the screen cause the feed material to flow
rapidly at the feed end of the screen. The resulting thin bed of particles stratifies more
quickly and therefore has a faster screening rate for the very fine material than would be
possible on a slower moving thick bed. Towards the discharge end of the screen, the slope
decreases to slow down the remaining material, enabling more efficient screening of the

near-size material.

Above figure shows a typical bed depth profile on banana screens.
The various slopes may also incorporate deck media with different apertures to meet the
particular process requirements. The screens are commonly designed to fit modular rubber
or polyurethane deck panels. However, woven wire or punched plates may also be used,
depending on requirements.
The capacity of banana screens is significantly greater and is reported to be up to three or
four times that of conventional vibrating screens.

#banana screen #vibrating screen #banana vibrating screen

Heavy duty electromagnetic vibrating feeders equipped with two electromagnetic vibrators are used in the hardware industry.

2025-06-13

In many aspects of industrial production, material handling is a crucial part. As a key equipment in the field of material handling, the vibrating feeder, with its excellent performance and wide range of applications, is becoming a reliable assistant for major industrial enterprises to improve production efficiency and reduce costs.

fastener vibrating feeder in hardware industry

A vibrating feeder is a device used in the production process to evenly, continuously, or quantitatively feed lumpy, granular, and powdery materials from storage bins or other storage equipment into receiving equipment. The vibrating feeder is suitable for conveying fasteners such as bolts and nuts in the hardware industry. In order to improve the conveying capacity and maximum working weight of the vibrating feeder, the VRV team (Professional vibrating feeder manufacturer from China) designed a vibrating feeder driven by two vibrators for customers. This feeder has the following advantages:

(1) High-efficiency and stable feeding performance

Designed based on advanced vibration principles, while the VRV team improves the handling vibrating feeder capacity, the vibrating feeder control system can accurately control the feeding speed and flow rate of materials according to production requirements. Whether in a high-speed production line or in a scenario with extremely high requirements for feeding accuracy, it can maintain a stable feeding state, avoiding problems such as material blockage or uneven feeding, and ensuring the smooth progress of the production process.

(2) Strong adaptability

The flexible design of the vibrating feeder can adapt to a variety of material characteristics, including materials with different particle sizes, humidity levels, densities, and flowabilities. From bolts, nuts, screws, rivets, washers to gears, oil drum lids, etc., bulk materials in the hardware industry are characterized by heavy weight, hard surfaces, and easy wear. The vibrating feeder can be made of anti-corrosion materials with special wear-resistant coatings according to the characteristics of the materials, which not only extends the service life of the equipment but also protects the properties of the materials.

(3) Low energy consumption and low maintenance cost

Compared with traditional feeding equipment, the vibrating feeder has lower energy consumption. The advanced design of its vibration system reduces energy loss, ensuring efficient feeding while reducing production costs. In addition, the equipment has a simple structure with fewer components and uses high-quality wear-resistant materials, reducing the amount of maintenance work and maintenance costs. Routine maintenance only requires regular inspection of the operating status of the vibrating motor and the fastening condition of the equipment, greatly reducing the labor intensity of workers.

heavy-duty vibrating feeder

The vibrating feeder system can choose two driving methods, electromagnetic vibrators and unbalanced motors, according to different application scenarios. Compared with the large handling capacity of motor vibrating feeders, electromagnetic vibrating feeders have higher precision in handling materials. We can remotely and precisely control the feeding speed through the controller and PLC.

VRV team provide comprehensive after-sales service guarantees for electromagnetic vibrating feeders for the hardware industry:

1. The warranty period for all delivered goods is one year (excluding consumable parts such as wear-resistant lining plates and rubber seals), starting from the date when the equipment passes the commissioning and acceptance inspection.

2. Accept all the provisions of the tender document and deliver the goods in a timely manner with guaranteed quality and quantity as required by the contract.

3. Ensure that the products leaving the factory meet relevant international, national and industry standards and comply with the technical conditions specified in the contract to guarantee the reliability of product operation.

4. In case of any product quality problems found during the warranty period, our company will strictly fulfill the replacement or compensation responsibilities stipulated in the contract.

5. For any malfunctions of the equipment after the warranty period, if our company's cooperation is needed, we will actively and fully cooperate.

#Heavy duty Electromagnetic vibrating feeders #vibrating feeder for hardware industry #fastener vibrating feeders

How to Choose the Vibratory Feeder

2025-06-13

Vibratory feeders have been used in the manufacturing industry for several decades to efficiently move fine and coarse materials which tend to pack, cake, smear, break apart, or fluidize. Because they can control material flow, vibratory feeders handle bulk materials across all industries, including pharmaceuticals, automotive, electronic, food, and packaging. These feeders also advance materials like glass, foundry steel, and plastics at construction and manufacturing facilities.

Feeders can range from small base-mounted, pneumatic-powered models moving small quantities of dry bulk material to much larger electro-mechanical feeders that convey tons of material an hour. Users turn to vibratory feeders when they want to move delicate or sticky materials without damaging or liquefying them.

Vibratory feeders handle a wide assortment of materials including but not limited to: almonds, crushed limestone, shelled corn, powdered metal, metal billets, various pipe fittings, scrap brass and bronze, crushed and shredded automobiles, hot dross, and much more. Because they emit precise vibrations, vibratory feeders are also used to process small parts, like coins, washers, or O-rings, as they move along a belt conveyor.

Other common applications of vibratory feeding include:

* Controlled flow of ingredients to mixing tanks
* Sprinkling toppings or coatings on food and dairy products
* Adding binders and carbons to foundry sand reprocessing systems
* Chemical additive feeding in the pulp and paper bleaching or chip handling processes
* Feeding metal parts to heat treating furnaces
* Feeding scrap or glass cullet to furnaces

Manufacturers have upgraded and modified vibratory feeders and conveyors over the years to enhance their role in multiple processing applications. The latest equipment offers increased energy savings, more precise control over material flow, easier maintenance, and a broader variety of options. Leading suppliers also now provide better technical support, and, in some cases, faster delivery of product to your plant.

Virtually all vibratory equipment—regardless of type or size—is built with materials that can withstand the harsh environment of the manufacturing industry. Vibratory feeder trays can be made from stainless steel which is far less susceptible to corrosive materials. The internal motor’s fully enclosed construction offers protection from environmental elements to ensure maximum uptime.

Vibratory feeders save users time and money on maintenance as well, because they have no moving parts, aside from the vibrating drive unit. This means they break down less frequently and vibratory feeder parts are easy to replace. Other advantages of vibratory feeders include: ergonomic design, adaptability and versatility, effectiveness and accuracy.

How to Select the Proper Vibrating Feeder Design
There are two basic designs available when selecting a vibrating feeder: electromagnetic and electromechanical. A third option—air-powered vibrating feeders—are basically an alternate to electromechanical feeders since they have the same simple brute force design concept—the vibratory drive is directly attached to the tray.

Here are the basic advantages and disadvantages to these three feeders:

Electromagnetic feeders provide variable intensity with typically fixed frequency of 3600 vibrations per minute (VPM). They only require single phase power, offer quick stopping, and are ideal for cold weather. However, they are sensitive to line voltage fluctuations and temperature swings are not suitable for hazardous areas. They also need constant tuning if there are rate or load changes.

These units work well with dry, free-flowing, pelletized or granulated material. They can control material flow from a few pounds to several tons per hours and can be custom designed to accommodate material flow from a few feet (with a single drive) to up to 20 feet (with multiple drives).

Electromechanical feeders are powered by twin rotary electric vibrators which provide a broader range of stroke/frequency combinations. Their flexibility is further enhanced with a variable frequency drive (VFD), which provides quick and easy adjustment without having to manually adjust the eccentric weights.

A VFD with dynamic braking or a starter with a dynamic brake will end the vibration faster to limit the erratic motion a shut down. This design provides the quietest operation and is less susceptible to head loads. These feeders work well in hazardous conditions when explosion proof vibrators are installed.

Air-powered feeders work best under hazardous conditions because they are driven by an air-cushioned piston vibrator, which produces smoother linear force and can work safely in high temperatures. It’s the simplest of the three feeders to maintain and the controls are the most economical.

While an air-powered feeder doesn’t require tuning, there are limitations to the physical size of the tray and feed rates. These units are also less suitable for outdoor operation because the air lines can freeze up. These feeders are also susceptible to head load.

Tray Designs Are Limitless
The shape, length, and width of modern feeder trays are almost limitless. Customers can order custom feeder trays to suit their unique process applications. Every configuration of flat, curved, vee, and tubular designs are available.

Units can be furnished with special coatings, such as neoprene, UHMW, urethane, non-stick polymer, non-stick textured surfaces, or removable abrasive-resistant steel plate. Liners made from either neoprene, UHMW, or urethane protect the feed tray while processing harsh materials. The trough can be furnished in steel or polished stainless steel to meet the most demanding requirements.

Trays can be designed for fast removal and cleanout to avoid cross contamination of materials and decreased production line downtime. Custom trays can have quick release clamps to enable removal of the tray and cover without tools. The tray is simply lifted and disconnected from the frame for easier cleaning.

Spring Systems from Steel to Fiberglass
Springs are an integral part of the feeding system process because they convert the vibration from the drive to the tray, thus causing the material to move. Like trays, springs today come in a variety of materials, sizes, and configurations depending upon the application.

Fiberglass springs are the most popular configuration for light- and medium-duty applications. Small electromagnetic feeders, light- to medium-duty conveyors, and most high-precision vibratory equipment use fiberglass or multiple pieces of fiberglass as their primary spring action material.

Steel coil springs are commonly used on heavy-duty and high-temperature applications. These coils are effective in ambient temperatures up to 300°F.

Dense rubber springs are typically used on heavy-duty feeders and conveyors to provide stability and motion control between the drive and tray. However, rubber springs are limited to use in environments below 120°F.

Air mount springs are designed to handle tough industries such as construction and mining, which present dirty, dusty, and wet environments. They withstand common issues such as rust and corrosion that typically lead to broken parts. They also reduce structural noise and are versatile.

Factors to Determine a Vibratory Feeder
Typically, a feeder application will require the movement of some given material with a known bulk density over a desired distance. Parameters that influence the sizing and design of a vibratory feeder include:

* The inlet and discharge conditions for that piece of equipment
* How the material is being placed on the feeding surface
* The dimensions of the incoming material stream
* Batch dumping vs. continuous flow
* Feeding another piece of equipment, such as a belt conveyor, bucket elevator or furnace
* Feed rate
* Material properties, including bulk density and particle or part size.

The distance the material must travel drives the length of the unit and may include some additional length to properly interface with the receiving equipment. The volume of material moved per hour plus the material’s bulk density helps determine the width and depth of the vibratory tray. The size of equipment that passes material onto the vibratory feeder also factors into the feeder’s width.

Proper Location of Vibrators on Feeders
There are several options when deciding where to install the vibrators on a particular feeder model. With vibratory feeders, there is a concern about the product discharge height, as the equipment is often feeding material downstream to other devices.

Typically, on vibratory feeders the default location is “below deck” where the vibrators are attached on the underside of the unit. With below deck vibrators, the feeder will need a higher discharge height compared to a similarly-sized unit where the vibrators are “side mounted” or even in some applications where the vibrators are attached “above the deck.”

Functionally, there is no benefit to locating the vibrators above, on the side or below the unit. Provided the structure is appropriately designed for the force output of the vibrators and they “sense” each other, either vibrator location can provide satisfactory results.

Controlling Material Flow from a Feeder
Precise metering of material flow (whether moist or dry) onto trays or other receptacles is critical to the operation of any vibratory feeder, particularly those equipped with a hopper. Several factors below influence the material flow, but when all three are combined, it is possible to vary the flow rate and provide very repeatable results as the material cascades off the feeder end.

Bed depth of material on the tray. The material must be free flowing and always available in the hopper to charge the feeder. Not enough material will “starve” the feeder, reduce the bed depth and cause inconsistent discharge rates.

A hopper slide gate helps adjust material depth. Opening the gate allows for a higher volume of material to be removed from the hopper, resulting in a deeper material flow and higher volume off the feeder end. Likewise, reducing the opening restricts the volume of flow out of the hopper, resulting in more shallow material flow as well as lower volume.

Frequency of vibration applied to the feeder tray. Different materials respond better to different frequencies of vibration which influences the type of vibrator installed on the feeder.

For example, rotary electric vibrators are designed with various frequencies to accommodate different materials:

* Two-pole vibrators that operate at 3600 vibrations per minute (VPM) have the highest frequency and smallest amplitude
* Four-pole vibrators that operate at 1800 VPM
* Six-pole vibrators that operate at 1200 VPM
* Eight-pole vibrators that operate at 900 VPM

Heavier materials tend to require higher frequency drives while lighter materials feed more effectively with lower frequency drives.

Vibrators are installed based on the selected feed rate. This selection is based on the frequency of vibration and the maximum force output of the vibrator.

Necessary adjustments to the eccentric weights of the vibrators can be made to reduce the force output from the unit’s rated maximum. For a given frequency, more force output will result in a larger amplitude or stroke of the finished equipment.

Technical Support is Key
Purchasing and installing a vibratory feeder poses fewer risks today because of increased technical assistance before and after the sale. Material samples of various densities and configurations can be tested beforehand to determine the optimum piece of vibratory and conveying equipment. This pre-testing virtually eliminates the potential problem of installing an under or oversized piece of equipment for the job at hand.

Proper screen tension is crucial for effective screening

2025-06-13

Proper screen tension is crucial for effective screening and longer screen life. Proper screen
tension helps spread material across the full width of the screen. Uniform tension must be
also maintained on the screen surface to prevent whipping and to maintain contact between
the screen surface and the capping rubber (also called channel rubber, bucker-up rubber,
etc.) on the longitudinal support (camber) bars for preventing damage to (breakage of)

screen cloth.

As shown in above figure, for proper screen tensioning; tension plates (also called tension
bars, tension rails, clamp down rails, side hold down, etc.) and tension bolts with swivel nuts
(or swivel/spherical/taper washer and hex nut) are commonly used for heavy wire cloth or
perforated plate (screen cloth) with edge hooks (hook strips) on side tensioned vibrating
screens. Tension plates, tension bolts, etc. are called screen accessories.
During operation, as the screen may become loose due to stretching (as the screen cloth
wire wears thin) and loosening of the hooks, it is important to periodically check the screen,

and retighten the hooks.

Above figure shows the most common type of tensioning device for fine and medium weight
cloth consisting of tension wedge and rubber spring. This tensioning device has the
advantage of quick tightening or easy release, while at the same time providing constant
tension through the action of the molded rubber spring. Because the wedges are held firmly

in place by spring action, constant attention (retightening) is not required.

Above figure shows other automatic tensioning device for fine and medium weight wire cloth
or light weight perforated plate consisting of steel spring assembly. As the screen cloth gets
stretched, the springs automatically keep the cloth in constant tension.

#effective screening #vibrating screening #efficient screening

The main obstacles to efficient screening

2025-06-13

The main obstacles to efficient screening are plugging/pegging, blinding and carryover. Each can be minimized with a variety of solutions.

Plugging/pegging happens when near-size particles become lodged/wedged, blocking the openings. Generally, if loose particles/rocks (“Carrots” Shape) get stuck in the media holes it is called plugging whereas if particles get jammed in the openings, it is called pegging. Solutions may include increasing stroke, changing opening shape (using long-slotted openings instead of standard square openings), using urethane or rubber media, using selfcleaning (non-blinding) screening surfaces having wires that are crimped to form openings but individual wires are free to vibrate and using ball trays (also called bouncing ball decks).

As shown in above figure, the ball trays consist of compartments with perforated plate or wire cloth with relatively large openings placed beneath the screen cloth. Generally, rubber balls are placed in each compartment that freely bounce during the operation of the screen. They strike the underside of the screen surface and therefore randomly knock out the clogged material. The secondary vibration generated in the screen cloth due to striking of the balls also prevents fine particles from sticking and building up on the wires. In most cases, a ball tray will be effective with material containing as much as 5% moisture. The material that passes through the screen cloth passes through the perforated plate or wire cloth at the bottom of the ball tray where it can be collected.
Ball trays are generally used for coarse meshes which can withstand higher impact energy from the balls. Balls are not recommended for fine screen meshes because they may damage the screen cloth.

As a rule of thumb, screening at less than around 5 mm aperture size must be performed on perfectly dry or wet material, unless special measures are taken to prevent blinding. Blinding occurs when moisture causes fine particles to stick to the surface and gradually cover the openings. In this case, changing stroke and increasing speed may help. Use of different surface media also may be considered. The other options are to consider ball trays and heated decks. Heated decks have an electric current in the wire that heats and dries the material so that it easily knocks itself loose as the screen vibrates. Heated deck is a more effective method of preventing blinding in damp materials (1.5 to 6% moisture) than the ball tray.
Heating transformers, consuming from 2 to 3 KVA per foot of screen length, can be used with any screen cloth weighing less than about 1.5 lbs. per square foot. The current flows at a low voltage (1 to 12) and a high amperage to produce temperatures on the screen wires ranging from 80 to 150°F. This heat is not intended to dry the material being screened, but only to dry the interface between the wire and adhering particles (e.g. clay particles) sufficiently to break the adhesive bond holding the particles to the wire. The screen vibration does the rest.
Wet screening allows finer sizes to be processed efficiently down to 250 μm and finer.
Adherent fines are washed off large particles, and the screen is cleaned by the flow of pulp and additional water sprays. Carryover occurs when excessive undersize particles fail to pass through the openings. Solutions may involve changing stroke, speed or reversing screen rotation; changing wire diameter or the shape of the opening to increase open area; changing the angle of inclination and changing feed tonnage.

#vibrating screen #efficient screening #vibrating screen plugging

Vibrating Screen Installation, Start up and Adjustments

2025-06-13

Installation
The supporting steel structures on which the screen and drive motor are mounted must be sufficiently strong and braced to accept without deflection the dynamic loads caused by the
vibration of the screen.
Adequate clearances must be allowed between the screen and the fixed structure, chutes etc., to allow enough space because the movement of the screen is large in the so-called resonance areas when starting and stopping the screen.
Check that the height difference of separate springs pedestals (in the same end of the screen) are not more than ± 3 mm. Transparent water hose and water may be used to check the height difference. Pedestals surface must be horizontal.
Tighten all bolts in the recommended sequence if any and to the recommended torque.

Check the screen’s installation angle.

Check that all of the spring axes are vertical.

Check rotation directions of the motor/s.

In case of screen driven by motor and cardan shaft, the vertical position of the motor must be fixed so that the centre line on the screen’s shaft is approx. 5 mm higher than the centre line of the motor shaft. During running with material, cardan shaft should be close to horizontal. In case of belt drive, tension the belts as per manufacturer’s recommendation.
Make sure that all guards are properly fastened and all the safety devices are installed and they are working properly.
Earth the motor connection at the mains.
Have qualified electrician install overload, short-circuit and ground-fault protection.
If unbalance motor is installed onto a vibrating screen, leave slack in electrical cable so that cable does not become taut during vibration cycle and cause stress on wire connection.
In case of a linear motion vibrating screen, interlock the two unbalance motors rotating in opposite directions and install separate overload protection. The screen’s control circuit must be arranged so that if one unbalance motor becomes de-energized, the other unbalance motor will automatically and immediately become de-energized. Failure to properly interlock screen’s unbalance motors could result in damage to the screen if one unbalance motor fails (if only one unbalance motor of a pair is powered, the bearings in the unpowered unbalance motor will get damaged within a very short time).
If the unit is going to be stored before start-up, once a month, the shaft should be rotated several times to re-lubricate the upper bearing portion.

Start up
After start (first 1-2 minutes) make sure that screen is starting and running properly.
Check the feed of the material. It must spread to whole width of the screen.
Check screening result.

Above figure shows three potential screening scenarios. Screening finishes early on the
deck at (A), which results in a loss of production; screening not completed (B), which results
in carryover and contaminated material; and optimal screening (C), which provides for higher
production with less contamination.
Check stroke length and stroke angles in each corner. Stroke length must be within one mm to each other in the same end of the screen!
Check for oil/grease leaks in the mechanism.
After 4 to 6 hours, check that bearing temperature is even in each bearing. Normal running temperature can be about 70°C when ambient temp is 20°C.
After running the screen for about 50 hours, check the following:

Fastening / tightness of mechanism bolts.
Fastening / tightness of counterweight.
Fastening of screening medias.
Alignment / tightness of V-belts.

Mechanism has tendency to leak a little bit after few operation hours or days. This leak is mainly extra grease coming out of sealing. Leaking should stop in few hours or days.
The first oil change for the mechanism must be done as per manufacturer’s recommendation
(in case of gears, after about 100 hours of operation).

Screen Adjustments
If the screening performance is not satisfactory, check first that the screen meshes are correct for the application and that the feed and discharge arrangements are satisfactory. Feed to the screen must be arranged so that the material is fed uniformly across the entire width of the screen.
As feed material is a mixture of varying sizes, oversize material will restrict the passage of undersize material, which results in a build-up, or bed depth, of material on the screen surface. Bed depth diminishes as the undersize material passes through the screen openings. For efficient screening, the material bed should not reach a depth that prevents undersize from stratifying before it is discharged. Hence for maximum screening efficiency depth of bed should be proper. As stated earlier, depth of bed (in dry screening) should not
exceed four times the opening size at the discharge end of the screen. Depth of bed can be
changed by adjustments in speed, stroke length, rotation (or throw) direction and angle of
inclination. However, always make only the minimum adjustments necessary to achieve the
desired result.
If adjustments are necessary, they should be made in the order given below.

Stroke frequency adjustment
Stroke length adjustment
Adjusting the inclination of the screen body

Try the action of each measure separately and singly. Try one action at a time and observe
the result before taking on the next one.
Adjustment of the stroke length is done by adding or removing counterweights. At both ends of the same shaft there has to be exactly the same number of counterweights. Higher stroke delivers a higher carrying capacity and travel rate, while reducing plugging, blinding and enhancing stratification. Always check the screen speed/stroke length combination so that the maximum allowed acceleration (G-force) of the screen is not exceeded.
Stroke frequency adjustment can be done by changing V-belt pulleys or inverter parameters.
Higher frequency/speed may decrease depth of bed. Rotation speed affects the G-forces.
More speed, more G-forces with same counter weights.
Always ask manufacturer before changing rotation speed. Wrong speed can run the screen near to its natural frequency leading to screen body failure.
Also remember that increased G-forces shortens the bearing life time!
Adjusting the inclination of the screen body is done by lifting or lowering other end of the screen or feeder. Increasing the angle of inclination causes material to travel faster, which can be advantageous in certain dry screening applications. Although, there may be a point where too much incline will hinder efficiency as fines may roll over the media rather than passing through.
Do consult the manufacturer for advice on the selection of the optimum speed, stroke length, angle and frequency, if mesh sizes are changed or different material is fed to the screen.

#Vibrating Screen #Vibrating Screen Installation #Vibrating Screen adjustment

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