Vertical Pressure Leaf Filter
A Vertical Pressure Leaf Filter is an enclosed industrial filtration system designed for efficient liquid-solid separation, clarification, and recovery of filter cake. It uses multiple leaf-shaped filter elements installed vertically inside a pressure vessel to provide a large filtration area within a compact footprint.
SEPARATECH designs and manufactures vertical pressure leaf filter systems for applications including edible oil refining, food and beverage processing, chemical processing, petrochemical applications, mining, metal finishing, and other industrial filtration processes.
The system can be configured for dry or wet cake discharge, with filter leaf materials, filtration area, vessel design, and operating configuration customized according to the process requirements.
What Is a Vertical Pressure Leaf Filter?
A Vertical Pressure Leaf Filter consists of a closed vertical pressure vessel containing multiple filter leaves mounted on a common manifold. During filtration, the process liquid is introduced into the vessel under pressure. The liquid passes through the filtration surface of the leaves, while suspended solids are retained on the outer surface and gradually form a filter cake. The clarified liquid flows through the internal drainage channels of the filter leaves and is collected through the filtrate outlet.
The basic components include:
- Pressure vessel;
- Vertical filter leaves;
- Central manifold;
- Filter leaf support structure;
- Filtrate outlet;
- Feed inlet;
- Cake discharge system;
- Cover and sealing system;
- Pressure and process instrumentation;
The vertical arrangement allows a large filtration area to be installed within a relatively small floor area, making the design particularly useful where plant space is limited but sufficient overhead clearance is available.
Vertical Pressure Leaf Filter Working Principle
The Vertical Pressure Leaf Filter operates by pressure-driven solid-liquid separation.
The filtration cycle can generally be divided into several stages.
1. Precoating
For applications requiring filter aid, a suitable filter aid is circulated through the system to form a uniform precoat layer on the filter leaves.
Depending on the process, filter aids may include:
- Bleaching earth;
- Diatomaceous earth;
- Perlite;
- Cellulose;
- Other process-specific filter aids.
The precoat layer helps improve filtrate clarity and provides a controlled filtration surface.
2. Filtration
The unfiltered liquid enters the pressure vessel.
Pressure forces the liquid through the filter cake and filter leaf media, while suspended solids are retained on the filtration surface.
The filtered liquid then enters the internal drainage channels of the filter leaves and flows to the common manifold.
3. Cake Formation
As filtration continues, solids accumulate on the filter leaf surfaces and form a filter cake.
The filter cake itself becomes an important part of the filtration process because the progressively formed cake provides additional particle retention.
4. Filtration Completion
As the filter cake becomes thicker, filtration resistance increases.
The filtration cycle is normally stopped when the process reaches its specified:
- Differential pressure;
- Filtrate flow;
- Filtration time;
- Cake capacity.
5. Cake Discharge
Depending on the process, the filter can be configured for either dry cake discharge or wet cake discharge.
Key Advantages of a Vertical Pressure Leaf Filter
A properly designed Vertical Pressure Leaf Filter provides several advantages for industrial liquid-solid separation.
Large Filtration Area in a Compact Footprint
The vertical arrangement allows multiple filter leaves to be installed inside a single pressure vessel. This provides a large filtration surface without requiring a large floor area.
High Filtrate Clarity
The combination of filter media and filter cake can provide high-quality clarification, making vertical pressure leaf filters suitable for processes where liquid clarity is important.
Enclosed Filtration
The filtration process takes place inside a closed pressure vessel. This helps reduce:
- Product exposure;
- Spillage;
- Operator contact with process liquids;
- Exposure to fumes in appropriate applications.
Closed operation is particularly valuable when processing hazardous, volatile, corrosive, or high-value liquids.
No Disposable Filter Cloth
Metal filter leaves can eliminate the recurring replacement of conventional filter cloth used in some other filtration systems.
This can reduce consumable requirements and simplify maintenance.
Dry or Wet Cake Discharge
The system can be configured according to the characteristics and value of the filter cake.
Dry cake discharge is particularly useful when recovery of solids or minimization of product loss is important, while wet discharge can be appropriate when the cake is difficult to dry or must be transported as slurry.
Easy Filter Leaf Inspection and Maintenance
The filter leaves can be removed from the vessel for:
- Inspection;
- Cleaning;
- Rescreening;
- Repair;
- Replacement.
This is particularly important for long-term industrial operation.
Vertical Pressure Leaf Filter Design
SEPARATECH Vertical Pressure Leaf Filter systems can be engineered according to the required filtration area, process conditions, materials of construction, and discharge method.
Typical design considerations include:
- Filtration area;
- Number of filter leaves;
- Filter leaf spacing;
- Vessel diameter;
- Vessel volume;
- Design pressure;
- Design temperature;
- Filter leaf material;
- Filter mesh;
- Cake volume;
- Cake discharge method;
- Process connections;
- Automation requirements.
The vessel and pressure-containing components can also be engineered to applicable pressure-vessel requirements, including ASME or CE-related requirements where specified.
Pressure Leaf Filter Elements
The filter leaves are the most important filtration components in a Vertical Pressure Leaf Filter.
SEPARATECH supplies stainless steel pressure leaf filter elements with customized construction for different filtration applications.
Typical filter leaf construction can include multiple layers of stainless steel mesh, providing:
- Filtration;
- Mechanical support;
- Internal drainage;
- Structural stability.
Available materials may include:
- Stainless steel 304 / 304L;
- Stainless steel 316 / 316L;
- Stainless steel 904L;
- Duplex stainless steel;
- Other alloys according to process requirements.
Different mesh configurations and filtration surfaces can be selected according to the characteristics of the liquid and solids being filtered.
Dry Cake Discharge Vertical Pressure Leaf Filter
A Vertical Pressure Leaf Filter with dry cake discharge is suitable when the filter cake needs to be removed with minimal liquid content.
After the filtration cycle:
- The remaining liquid is drained;
- The cake may be dried using compressed air, inert gas, or steam depending on the process;
- A pneumatic vibrator loosens the cake from the filter leaves;
- The cake falls through the bottom discharge valve.
Dry cake discharge is widely used in applications such as:
- Edible oil filtration;
- Sugar filtration;
- Cocoa processing;
- Activated carbon removal;
- Molten sulfur filtration;
- Catalyst recovery.
The dry discharge configuration can help reduce product losses and facilitate solid recovery.
Wet Cake Discharge Vertical Pressure Leaf Filter
Wet cake discharge is suitable when:
- The filter cake is difficult to dry;
- Cake disposal is economical in wet form;
- The cake needs to be transported as slurry;
- Short regeneration cycles are preferred.
The cake can be removed from the filter leaves using a suitable washing or sluicing system.
The selection between dry and wet cake discharge should be based on the properties and value of the filter cake, downstream processing requirements, and overall process economics.
Vertical Pressure Leaf Filter Applications
Vertical Pressure Leaf Filters are used across a wide range of industrial processes.
Edible Oil Refining
One of the important applications is filtration during edible oil refining.
Applications include:
- Bleaching earth filtration;
- Activated carbon removal;
- Oil clarification;
- Removal of suspended solids.
Vertical pressure leaf filtration is particularly suitable where high filtrate clarity and controlled removal of filter aid are required.
Molten Sulfur Filtration
Vertical pressure leaf filters can be used for molten sulfur filtration to remove solid impurities from molten sulfur.
The closed pressure filtration system and appropriate filter leaf materials allow the equipment to be integrated into industrial sulfur processing systems.
Chemical Processing
Applications include:
- Catalyst recovery;
- Chemical clarification;
- Process liquid filtration;
- Removal of suspended solids.
Petrochemical Processing
Pressure leaf filtration can be used for the removal of catalyst fines and other solid contaminants from process liquids.
Food & Beverage
Applications may include:
- Juice;
- Beer;
- Wine;
- Sugar solutions;
- Sweeteners;
- Other process liquids.
Mining and Metal Processing
Vertical pressure leaf filters can also be applied to processes involving:
- Pregnant liquors;
- Carbon fines;
- Electrolytes;
- Pickle liquor;
- Other process solutions.
Vertical Pressure Leaf Filter for Edible Oil Refining
The Vertical Pressure Leaf Filter is particularly important in edible oil refining applications. During bleaching, bleaching earth or other adsorbents are mixed with oil to remove pigments and other impurities. After the bleaching step, the filter must efficiently remove the spent bleaching earth from the oil.
A pressure leaf filter provides:
- Closed filtration;
- Large filtration area;
- High filtrate clarity;
- Efficient filter-aid removal;
- Reduced product loss;
- Dry or wet cake discharge options.
For edible oil applications, filter leaf material and mesh selection should be matched to the oil, temperature, filter aid, filtration cycle, and required product quality.
Vertical Pressure Leaf Filter vs. Horizontal Pressure Leaf Filter
The two main pressure leaf filter configurations are vertical and horizontal.
| Feature | Vertical Pressure Leaf Filter | Horizontal Pressure Leaf Filter |
|---|---|---|
| Vessel orientation | Vertical | Horizontal |
| Floor space | Compact | Larger footprint |
| Headroom | Requires sufficient overhead space | Lower headroom requirement |
| Filter leaf access | From top | Through shell or bundle retraction |
| Dry cake discharge | Excellent for gravity-assisted discharge | Suitable with mechanical discharge systems |
| Typical application | Compact industrial filtration | Large-capacity filtration |
| Filtration area | Small to large | Large to very large |
A Vertical Pressure Leaf Filter is often preferred when floor space is limited but adequate building height is available. Horizontal pressure leaf filters can be advantageous where very large filtration areas, large cake volumes, or specific maintenance arrangements are required.
Vertical Pressure Leaf Filter Technical Specifications
| designation | filtering area m2 | no. of leaves | leaf spacing mm | height m | vessel vol. L | weight Kg |
|---|---|---|---|---|---|---|
| VPLF7 | 7 | 9 | 50 | 2.2 | 0.42 | 500 |
| VPLF10 | 10 | 9 | 70 | 2.5 | 0.8 | 800 |
| VPLF12 | 12 | 11 | 70 | 2.6 | 1 | 900 |
| VPLF15 | 15 | 12 | 70 | 2.7 | 1.3 | 1100 |
| VPLF20 | 20 | 12 | 70 | 3.1 | 1.7 | 1300 |
| VPLF25 | 25 | 13 | 70 | 3.2 | 1.9 | 1500 |
| VPLF30 | 30 | 15 | 70 | 3.3 | 2.2 | 2000 |
| VPLF36 | 36 | 15 | 70 | 3.4 | 2.3 | 2500 |
| VPLF40 | 40 | 16 | 70 | 3.5 | 2.8 | 2800 |
| VPLF45 | 45 | 16 | 70 | 3.6 | 2.9 | 3100 |
| VPLF52 | 52 | 16 | 75 | 3.8 | 3.5 | 3600 |
| VPLF60 | 60 | 17 | 75 | 3.9 | 4.3 | 4000 |
| VPLF70 | 70 | 18 | 80 | 4.4 | 5.6 | 4800 |
| VPLF80 | 80 | 20 | 80 | 4.5 | 7.2 | 5200 |
| VPLF90 | 90 | 20 | 80 | 4.5 | 7.6 | 5500 |
| VPLF100 | 100 | 20 | 80 | 4.5 | 8.6 | 5800 |
| VPLF120 | 120 | 20 | 80 | 5 | 10.2 | 6000 |
How to Select a Vertical Pressure Leaf Filter
Selecting the correct Vertical Pressure Leaf Filter requires more than simply choosing a filtration area. The main process parameters include:
Process Liquid
Provide information about:
- Liquid composition;
- Viscosity;
- Temperature;
- Corrosiveness.
Solids Loading
The concentration and characteristics of suspended solids affect:
- Required filtration area;
- Cake volume;
- Filtration cycle;
- Filter leaf configuration.
Required Filtrate Quality
The target filtrate clarity determines the appropriate:
- Filter media;
- Mesh;
- Filter aid;
- Precoat procedure.
Cake Characteristics
Consider:
- Cake thickness;
- Cake moisture;
- Cake disposal;
- Cake recovery value.
Required Capacity
The required production rate determines the appropriate filter area and number of filter leaves. SEPARATECH can select and configure a Vertical Pressure Leaf Filter based on actual process conditions rather than relying only on nominal equipment capacity.
Vertical Pressure Leaf Filter Maintenance
Regular maintenance helps maintain filtration performance and extend the service life of the equipment. Important maintenance items include:
- Inspecting filter leaves;
- Cleaning filter mesh;
- Checking filter leaf connections;
- Inspecting gaskets and seals;
- Checking the cake discharge system;
- Inspecting valves and instrumentation;
- Checking the pneumatic vibrator;
- Inspecting the pressure vessel.
Filter leaves should be inspected if the system shows:
- Increasing filtration pressure;
- Reduced filtrate flow;
- Poor filtrate clarity;
- Shorter filtration cycles.
SEPARATECH also supplies pressure leaf filter elements, replacement filter leaves, and filter leaf rescreening services for existing pressure leaf filtration systems.
Customized Vertical Pressure Leaf Filter Solutions
Not every filtration process can be solved with a standard filter model. SEPARATECH can customize the Vertical Pressure Leaf Filter according to:
- Required filtration area;
- Vessel material;
- Filter leaf material;
- Filter mesh;
- Operating pressure;
- Operating temperature;
- Cake discharge method;
- Heating requirements;
- Automation requirements;
- Process connections.
The system can be engineered for new filtration projects as well as specific process requirements for existing plants.
Why Choose SEPARATECH?
SEPARATECH focuses on industrial solid-liquid separation and pressure leaf filtration. Our capabilities include:
- Vertical pressure leaf filter design;
- Horizontal pressure leaf filter design;
- Pressure leaf filter elements;
- Filter leaf replacement;
- Filter leaf rescreening;
- Customized filtration solutions;
- Engineering support.
Our engineering team can work with customers to evaluate process conditions, select suitable filter leaf configurations, and develop a filtration system appropriate for the application.
Frequently Asked Questions
What is a Vertical Pressure Leaf Filter?
A Vertical Pressure Leaf Filter is an enclosed pressure filtration system that uses multiple vertically arranged filter leaves to separate suspended solids from liquids.
How does a Vertical Pressure Leaf Filter work?
The process liquid enters the pressure vessel under pressure and passes through the filter leaves. Solids are retained on the filter leaf surface while clarified liquid flows through the internal drainage channels to the filtrate outlet.
What are the advantages of a Vertical Pressure Leaf Filter?
Key advantages include a compact footprint, large filtration area, enclosed operation, high filtrate clarity, and the ability to configure dry or wet cake discharge.
What industries use Vertical Pressure Leaf Filters?
Common applications include edible oil refining, food and beverage processing, chemical processing, petrochemical processing, mining, metal finishing, and sulfur filtration.
Can the filter leaves be customized?
Yes. Filter leaf dimensions, materials, mesh configuration, and construction can be customized according to the filtration application.
Can you replace filter leaves in an existing pressure leaf filter?
Yes. Replacement filter leaves can be manufactured according to existing filter leaf samples, drawings, dimensions, and application requirements.
Conclusion
A Vertical Pressure Leaf Filter provides an enclosed and efficient solution for industrial liquid-solid separation where high filtrate clarity, large filtration area, compact installation, and reliable cake discharge are required. With customized filter leaves, pressure vessel configurations, and dry or wet cake discharge options, the system can be adapted to a wide range of industrial filtration processes.
SEPARATECH designs and manufactures Vertical Pressure Leaf Filter systems and pressure leaf filter elements for edible oil refining, chemical processing, food and beverage, petrochemical, sulfur filtration, mining, and other industrial applications.
Contact SEPARATECH for a customized Vertical Pressure Leaf Filter solution based on your process conditions and filtration requirements.