Precision Filters, Security Filters, Cartridge Filters, Bag Filters

Overview of Precision Filters

Precision filter(Also known as security filter)The outer shell of the cylinder is generally made of stainless steel material, and the interior is made ofPPTubular filter elements such as melt blown, wire fired, folded, titanium filter element, activated carbon filter element, etc. are used as filter elements. Different filter elements are selected according to different filter media and design processes to meet the requirements of effluent quality. The body can also be equipped with a quick installation type for convenient and efficient replacement of filter elements and cleaning. This device is widely used in industries such as pharmaceuticals, chemicals, food, beverages, water treatment, brewing, petroleum, printing and dyeing, and environmental protection. It is an ideal equipment for various liquid filtration, clarification, and purification processes.

Anhui Xiangpai Machinery Manufacturing Co., LtdFilter mesh accuracy conversion

micron10 25 30 40 50 80 100 120 150 200 400 800 1500 3000

mm0.01 0.025 0.03 0.04 0.05 0.08 0.1 0.12 0.15 0.2 0.4 0.8 1.5 3.0

Number of eyes1500 650 550 400 300 200 150 120 100 80 40 20 10 5

Number of eyes micron Number of eyes micron Number of eyes micron Number of eyes micron

2.5 7925 12 1397 60 245 325 47

3 5880 14 1165 65 220 425 33

4 4599 16 991 80 198 500 25

5 3962 20 833 100 165 625 20

6 3327 24 701 110 150 800 15

7 2794 27 589 180 83 1250 10

8 2362 32 495 200 74 2500 5

9 1981 35 417 250 61 3250 2

10 1651 40 350 270 53 12500 1

The size of powder particles is called particle size. Due to the complex shape of particles, there are usually several representation methods such as sieving particle size, settling particle size, equivalent volume particle size, and equivalent surface area particle size. The sieving particle size refers to the size of the sieve holes that particles can pass through, in order to1Inches（25.4mm）The number of sieve holes in the width of the sieve is represented, hence it is called“Number of eyes”At present, there is no unified technical standard for powder particle size both domestically and internationally, and each enterprise has its own definition and representation method for particle size indicators. There are different standards for sieve specifications in different countries and industries, therefore“eye”The meaning is also difficult to unify.

Currently compared internationallyopen up or clear out by poking or jabbingUse the calculated diameter of equivalent volume particles to represent particle size. useμmperhapsmmexpress.

The table below shows the mesh size and particle size of commonly used sieves in China（μm）Comparison table.

micron concept:micronIt's a unit of length,symbol[micron],pronounce as[miu].1micronequivalent to1One millionth of a meter(This is the meaning of the word 'micro')Conversion relationship: 1 000 000Picometer(pm) = 1micron(μm) 1 000nanometre(nm) = 1micron(μm) 0.001mm(mm) = 1micron(μm) 0.000...

Precision filter_Security filter_Cartridge filter_Bag Filter

Structural characteristics

Precision filters have many characteristics such as high pollutant holding capacity, strong corrosion resistance, good temperature resistance, large flow rate, easy operation, long service life, and no fiber shedding.

Various coating equipment, including top cotton filters and frame and bag filters, are suitable for fine chemical, oil, food and pharmaceutical, water treatment and other applications.

Characteristics of precision filters

1、Efficient removal of water, oil mist, and solid particles,100%remove0.01μControl the concentration of particles and oil mist above m0.01ppm/wt；

2Reasonable structure, small volume, and light weight;

3With8There are protective covers, plastic shells, and aluminum alloy shells to choose from.

4Three stage segmented purification treatment, long service life

Precision filter material

1Shell: Aluminum alloy;

2Protective cover: plastic cup, polycarbonate, metal cup, aluminum alloy;

3Filter cartridge material:B、CSeries of environmentally friendly special fibers and non-woven fabrics;DSeries

General principles for filter selection

1Import and export diameter

In principle, the inlet and outlet diameter of the filter should not be smaller than the inlet diameter of the matching pump, and generally consistent with the diameter of the inlet pipeline.

2Nominal pressure

Determine the pressure rating of the filter based on the maximum pressure that may occur in the filtering pipeline.

3Selection of pore size

The main consideration is the particle size of impurities that need to be intercepted, depending on the process requirements of the medium flow. The particle size that can be intercepted by various specifications of wire mesh is shown in the table below“Filter specifications”.

4Filter material

The material of the filter is generally chosen to be the same as the material of the connected process pipeline. For different service conditions, filters made of cast iron, carbon steel, low-alloy steel, or stainless steel can be considered.

5Calculation of filter resistance loss

At the rated flow rate, the pressure loss of a water filter is calculated to be0.52～1.2kpa

Filter filtration mechanism and influencing factors
There are two important mechanisms for fluid filtration. One is based on particle size, such as blocking, screening, and surface capture; Another type is adsorption, where particles adhere to the filter under chemical/electrical action. This requires each pharmaceutical factory to choose different filter membranes based on their actual needs.

Factors affecting filters
1Characteristics of fluids
Related to the characteristics of the fluid. For example, the viscosity and chemical/ionic identity of a fluid. The higher the viscosity of the fluid, the slower the flow rate under the same pressure conditions. There is more conflict between the fluid and the membrane, resulting in better filtration efficiency; For example, the mixing/contact between fluid and membrane also has a significant impact on the filtration effect, and the longer the mixing/contact time, the better the filtration effect. In addition, it should be noted that the characteristics of the fluid only affect the adsorption and retention effect of the membrane on the fluid, and do not affect the removal of particle size.
2The relationship between operations
Related to practical operational prerequisites, such as particle flow rate and filtration pressure. To achieve good filtering effect, it is common to choose a lower flow rate, and the lower the flow rate, the better the interception result. It has been proven that the structural movement of the membrane is detrimental to filtration. Once the structure of the membrane undergoes changes during the filtration process, particles and fibers can precipitate from the deep filter, affecting the filtration efficiency. However, the rate/pressure difference only has a significant impact on adsorption retention, and has a relatively small impact on the removal of ultrafine particles.
3Types of particles
The particle type is also closely related to the filter effect, and particles are divided into deformable particles and non deformable particles2Seed. Under certain pressure, deformable particles will enter the filter membrane and cause more blockage of filter mesh, and then affect the filtration effect, such as the filtration of gel. However, when non variable particle filtration occurs, a layer of cake like objects will form on the filter membrane.
4Types of filter membranes
Related to the example of filtration membranes, the pore size and structure of different filtration membranes are different. Some membranes have rigid structures, while others have movable structures. There is no unified national standard for the rated pore size of pre filtration membranes, and different manufacturers have their own definitions and methods. Therefore, when selecting and replacing businesses, it is important to pay close attention0.22μmThere may be significant differences in the filtration efficiency of pre filtration membranes produced by different manufacturers. The common pore size for sterilization filtration is defined by regulations, and each merchant follows a unified standard. Therefore, the selection and replacement process is relatively simplified.
5Filter material
Related to the filtering material, filtering materials are divided into hydrophilic (water infiltrates) and hydrophobic (water infiltrates) based on their relationship with water2Seed. Hydrophilic filters are mainly used for filtration and sterilization of water or water/organic solution mixtures, such as cellulose materials (regenerated cellulose, mixed cellulose esters)PVPPPolycarbonatePVDFImprove polyvinylidene fluoride; A hydrophobic filter is a filter that intercepts water or“guidance”Entering the filter membrane, it is mainly used for solvent, acid, alkali, and chemical filtration, tank/equipment respirators, process gas, fermentation inlet/outlet filtration, such asPTFEPolytetrafluoroethylenePVDFPolyvinylidene fluoride, polypropylene, polysulfone, polycarbonate, etc.

The function of cyclone separator

The main function of the cyclone separator equipment is to remove solid particles, impurities, and liquid droplets carried in the conveying medium gas as much as possible, achieving gas-liquid separation to ensure the normal operation of pipelines and equipment.

Working principle

Purified natural gas enters the cyclone separation zone inside the equipment through the inlet. When impurity containing gas enters the cyclone separation tube along the axial direction, the airflow is strongly rotated by the guiding effect of the guide blades. The airflow enters the cyclone tube in a spiral shape along the cylinder, and high-density droplets and dust particles are thrown towards the wall of the device under centrifugal force. Under the action of gravity, they fall down along the cylinder wall and flow out of the cyclone tube dust outlet to the storage area at the bottom of the equipment, and then flow out from the liquid outlet at the bottom of the equipment. The rotating airflow shrinks inside the cylinder and flows towards the center, forming a secondary vortex that flows through the air duct to the purified natural gas chamber, and then exits through the top outlet of the equipment.

performance index

Separation accuracy

The separation effect of cyclone separator: Under the design pressure and gas volume conditions, solid particles ≥ 10 μ m can be removed. At the operating point, the separation efficiency is 99%, and within the range of ± 15% at the operating point, the separation efficiency is 97%.

Pressure drop

Under normal working conditions, the pressure drop of a single cyclone separator at the operating point shall not exceed 0.05 MPa.

design service life

The design service life of the cyclone separator shall not be less than 20 years.

Structure Design

The cyclone separator adopts a vertical cylindrical structure, which is divided into a liquid collection zone, a cyclone separation zone, a purification chamber zone, etc. along the axial direction. Internally equipped with cyclone components, evenly arranged in the circumferential direction and fixed by upper and lower tube plates; The equipment is supported by a skirt, and the head is made of high-pressure resistant materialellipseType head.

Equipment ports provide pairing optionsflangeBolts, gaskets, etc.

Usually, there are three forms of gas inlet design:

a) Upper intake b) Middle intake c) Lower intake

For moisture, we often adopt a lower air intake scheme because lower air intake can utilize the space below the equipment to pre separate droplets with a diameter greater than 300 μ m or 500 μ m to reduce the load on the cyclone section. For dry air, middle or upper intake is often used. The upper intake is evenly distributed, but the equipment diameter and height will increase, resulting in higher investment; The central intake can reduce the height of the equipment and lower the cost.

Application scope and characteristics

The cyclone dust collector is suitable for purifying non viscous, non fibrous dry dust larger than 1-3 microns. It is a purification equipment with simple structure, easy operation, high temperature resistance, high equipment cost and resistance (80-160 mm water column), and cyclone dust collector is the most widely used in purification equipment. Improved cyclone separators can replace exhaust gas filtration equipment in some devices.