In the industry, filtering means separating solids from liquids through a medium and realizing the process of solid-liquid separation.
The filtering mediums commonly used in industry are as follows: granular mediums, fabric mediums, porous mediums and ceramic mediums.
The coal separating plant uses fabric medium. Vacuum filtration equipments for coal separating plant can be divided into two categories: disk type vacuum strainer and the cylinder type vacuum strainer equipment. They are mainly used for filtration, and can also be used for filtration of coal slime or flotation of tailings.
Filtering is a process of separating solid particles suspended in a gas or liquid. The basic principle is: under the action of the pressure difference, the suspension liquid (or gas) passes through a permeable medium (media), the solid particles are intercepted by medium, so as to realize the separation of liquid and solid.
The filter is a kind of equipment which uses porous filter media, intercepting solid particles in liquid and solid-particles mixture, to realize the solid and liquid separation. The Filter is widely used in chemical, petroleum, pharmaceutical, light industry, food, mineral processing, coal and water processing industries.
The Application of Mineral Processing
The mines concentrate dewatering widely uses vacuum filter. At present, the domestic-made vacuum filters mainly use filter cloth as medium, which has the disadvantages of high gas consumption, high energy consumption, low vacuum, high filter-cake moisture, low yield, filter cloth easily grinding, heavy repairing workload and so on.
In 1994, a domestic mine introduced a new vacuum filter which was used in zinc concentrate dewatering. The machine has the advantages of high efficiency and low energy consumption, so it is very popular. But due to the high cost of the equipment and its spare parts, many mines can only look at it.
In the early 1980s, Finland Outo Kumpu Company successfully developed the ceramic filter plate which can be used as a filter medium.
The aperture of the ceramic filter plate is generally 1 -- 5 microns (the most commonly used 1.5 – 2.0 microns). The micro pores have strong capillary action. When the ceramic filter works, under the action of the vacuum pump, only the liquid passes through the filter pores become filter liquid, while the solid and gas are blocked at the surface of the filter plate and become filter cake to realize the solid-liquid separation.
According to the technology of the ceramic filter model and based on the domestic technology, Lianyungang Boyun Machinery Limited Company has independently developed BY ceramic vacuum filter using the ceramic material as the filter medium (ceramic filtering plate).
The shape and working principle of the ceramic filter is similar with the disk vacuum filter’s. Namely, in the role of the pressure difference, when the suspension passes through the filtration medium, the particles are trapped and forms the cake on the surface of the medium, and the liquid passes through to achieve the purpose of solid-liquid separation.
The difference is the filter medium—the ceramic filter board has micro porous with capillary effect. The capillary force is greater than the applied vacuum force so that the pores are always filled with liquid. Whatever the situation is, the ceramic filter plate does not allow air to pass through.
Because no air passes, solid-liquid separation consumes low energy but have high vacuum degree. The ceramic filter is mainly composed of rotor, mixer, scraper components, slurry tank, distributor, ceramic filter, vacuum system, cleaning system, automatic control system and so on.
The ceramic filter finishes four working processes in a round. First, the suction work is completed in suction slurry (material) area. Second, the second dehydration is completed in the dry zone. Third, discharging is completed in the unloading zone. Fourth, the backwashing of the micro porous ceramic filtering plate is completed in
the washing area. The works go round and begin again.
Ceramic filter is a new type of solid-liquid separation equipment with high efficiency, and energy saving. The BY type ceramic disc vacuum filters made by Jiangsu Lianyungang Boyun Machinery Co. Ltd has been used in the iron concentrate filtering.
At present, the products have been widely applied to iron ore, copper concentrate, lead concentrate, concentrate aluminum, nickel concentrate, gold concentrate, phosphorus fine ore, fluorite and so on in domestic and foreign big mining enterprises for filtering.
BY ceramic filters are selected and used in many mineral processing plants throughout the country, and received unanimous praise. At present, they already actively break into the international market, and a simulation model has been made for overseas exhibition.
In addition, because the concentrate moisture decreases by 3%, the annual savings in transportation costs are160000 yuan, the road consumption is reduced by 2.5%, the more reclaiming of the sulfur concentrate is 4000t and the value of 300000 yuan. At the same time, it reduces environmental pollution, which can save environmental costs 300000 yuan. The capacity of a ceramic filter is equivalent to three imported filters or three fold belt type drum vacuum filters.
Although BY ceramic filter has large equipment investment, it has high benefits. Its biggest advantage is of high yield, low water, and can save energy more than 80%. They are mainly used in the dewatering of nonferrous metal ore lead, zinc, copper, molybdenum, sulfur concentrate.
With the development of energy, environmental protection and chemical industries, application field of the ceramic filter is gradually expanding and the requirements on the ceramic filter are also getting higher and higher.
Ceramic filters are not only used in nonferrous mines concentrate dewatering, but also can be applied in the solid-liquid separation of the titanium dioxide, impurity removing of chemical processing, dewatering of coal, sewage treatment of environmental protection industry and so on.
Jiangsu Boyun Machinery Limited Company has made BY ceramic filters in serialization and standardization production. At present, the company is researching and developing
super large ceramic filters, vertical ceramic filters and pressure-type ceramic filters.
The ceramic filter plate is the key component of the ceramic filter. The changes of ceramic filter plate material, bore diameter and strength directly affect the filtering effect. With the development and application of nanometer materials and other high-tech materials, excellent ceramic filter boards will certainly serve the society.
It is necessary to improve the appearance quality of domestic ceramic filter and manufacture precision.
The domestic ceramic vacuum filter can completely replace the imported ceramic filter. If the thousands of mines promote the use of domestic ceramic vacuum filters, only energy-saving benefit a year is dozens of billion, which reduces the noble metal flowing and the environmental cost, and water resources can be fully utilized and save a lot of foreign exchange.
It has the characteristics of high vacuum degree, high cake drying performance, high production efficiency and high recovery rate of solids. The filtrate is clear and working environment is clean with no pollution.
By using PLC control, the automation degree is high, the operation is simple and the operation is stable and reliable. It can be continuously operated so the utilization rate is high. Its advantages are as follows: significant energy-saving effect, low running cost, no need for expensive cloth and low spare-parts consumption. Compared with the traditional filtering equipment, it can save more than 90% energy.
The equipment has excellent performance, compact structure, low installation cost and easy maintenance.
The ceramic filter processes include 4 parts: the formation of the filter cake, cake dewatering, cake unloading and backwashing.
BY ceramic filter’s work is done by the PLC control. The control system is equipped with two modes: automatic and manual controls.
The manual mode starts each pneumatic valve, pump, motor and other device. Automatic mode has the function of automatic cleaning and automatic filtering.
Automatic filtering procedure is: to start the blender and disk → to start the vacuum pump (vacuum ≤ 0.7) and liquid pump → to close the discharge valve at the groove bottom→ water supply back flushing pipeline → slurry going into the filter tank → disc going into the slurry→ vacuuming the filter plate→ pressure difference forming the filter cake→ cake dewatering→ scraper scraping off filter cake from the disk→ filtrate backwashing the filter plate→ the conveyor belt send the concentrate into the ore bin.
The liquid level inside of the tank is tested by the ultrasonic level detector. The opening and closing of the valve is controlled according to the detection result. When the liquid reaches the limit, it automatically stops feeding. It automatically starts feeding when the liquid down to the lower level. The lower and upper values of the liquid level can be set according to the need of production. The filtrate height in the tank is controlled by the detector and a filtrate discharge valve. After working, the ceramic filter plate must be cleaned in order to maintain a good filtering effect. The cleaning of the filter plate uses ultrasonic and adding acid (oxalic acid, nitric acid) method. It has manual and automatic cleaning.
The difference of ceramic filter and other equipment for solid liquid separation is the filter medium for ceramic filter, ceramic filter plate.
BY ceramic filter is mainly composed of roller system, mixing system, feeding and discharging system, vacuum system, liquid discharge system, scraping system, back flushing system, combined cleaning (ultrasonic cleaning, automatic mixing acid cleaning) system, automatic control system, launder, and frame.
The trough body is made of corrosion resistant stainless steel, which plays the role of loading the slurry. The stirring system in the groove body stirs the mixture to avoid materials rapid subsidence. The ceramic filter plate is arranged on the roller and the roller is driven to rotate by the reducer’s stepless variable speed.
The Rotor (Roller)
The rotor is connected to the speed reducer of the main spindle through the coupling. The rotor is made of stainless steel and is rolled into a cylinder. Its two ends are supported on ball bearings by the heads. A head of the bearing is connected to the dispensing head. The filter plate is mounted on the cylinder flange. When working, the filtrate goes through the vacuum into the filter plate and goes to the distribution head. When back flushing, water passes through the head to the filter board. The other head of the shaft is connected to the motor reducer and is driven by the rotation of the rotor.
The Dispensing Head
The dispensing head is composed of a motionless disk and a dynamic disk rotating with the rotor. It can adjust the drying zone and the vacuum area. It can also adjust the pressing force by adjusting the bolt.
Mixing adopts mechanical stirring method according to the actual working conditions. When working, it plays the role of stirring, mixing the slurry, preventing precipitation and so on.
The scraper is made of ceramic and stainless steel materials. It is used to unload the materials. It can adjust the gap between blade and ceramic plate through bolts. The normal adjusting gap of the equipment is 0.5~1mm.
The Slurry Trough
The slurry trough is made of stainless steel through bending and welding. It is equipped with an overflow hole. Its function is to absorb, dehydrate and store the slurry.
The Main Spindle Speed Reducer
The main spindle speed reducer is connected to the rotor through the coupling. It generally uses the 90# industrial gear oil or 40# oil. When adding oil, the gas cap on the upper part can be unscrewed. When releasing the dirty oil, the cap on seat bottom can be unscrewed. There is no lubricant oil in the speed reducer when it goes out of the factory. It is necessary to add new oil after 100-hour running of the first-time oil. And the dirty oil has to be washed away. After that, the oil has to be replaced once for every four-month continuous work.
The Vacuum Pump
The vacuum pump adopts single stage liquid vacuum pump. It does not need to add the lubricating oil. When working, it must be kept to provide cooling water. The vacuum pump rotation is clockwise (from the motor direction).
The filter is composed of folding-deep filter element and case. The filter material is reinforced nylon micro porous filter membrane. When filtrating, the pressure is greater than 0.1MPa or flow is significantly decreased, which means the filter has been blocked. At this time, it has to replace filter element at once. When replacing the filter element, one end of the O ring should be held. The other end should be pulled tight by four-hole stainless steel fixed-plate and screw to avoid twisting the element. What has to be paid attention to is that the element should not be stained with oil.
The Ultrasound Equipment
The ultrasound equipment is composed of the switch power supply and the sounder.
The Waterway System
The waterway system is composed of a pressure reducing valve, filter, buffer, safety valve and stainless steel pipe. It washes the filter plate from the inside to the outside in each cycle.
The Gas Path System
The gas path system consists of vacuum system and valve system. The vacuum system consists of vacuum pump, filter pump drainage device or automatic liquid discharge device, and pipe. It plays the role of filtering, draining and drying. The valve system is composed of valve and electromagnetic valve to automatically control the valve.
The Use of Ultrasonic Cleaning of BY Ceramic Filter
BY ceramic filter’s ultrasonic cleaning system is composed of the ultrasonic generator generating high-frequency signals and the converter converting electrical energy into mechanical energy. The high frequency oscillation signals, which are generated by the ultrasonic generator, change into high frequency mechanical oscillation by transducer (super acoustic wave) and spread to the medium (washing liquid). The radiation of the ultrasonic in the washing liquid makes the liquid vibrate and forms tens of thousands of tiny bubbles. The bubbles form and grow in the negative pressure zone of the ultrasonic longitudinal propagation. They close rapidly in the positive pressure zone. This process is known as cavitation effect, in which the closure of tiny air bubbles can generate instantaneous high pressure that is higher than the atmospheric transient. The instantaneous high pressure is like a series of small explosions continuous to pound the ceramic plate surface, so that the dirt on the ceramic plate surface and in the gap drop rapidly, so as to achieve the purpose of cleaning.
The mechanism of ultrasonic cleaning are mainly in the following aspects: due to the cavitation effect, bubble collapsing produces strong shock waves. Under the shock wave, the partial dirt layer is stripped down, dispersed, emulsified and falls off.
The ultrasonic cleaning is usually combined with acid cleaning. Super acoustic accelerates the dissolution process of the chemical cleaning.
With the development of science, new technology and new products continue to emerge. Ultrasonic cleaning is the advanced and unique technology and is applied in more and more industries.
The failure rate of the ceramic filter is greatly reduced and the production efficiency and the equipment operation rate are increased. Because no air passes through the ceramic filter, so the vacuum loss is low, vacuum degree is high, moisture content of the filter cake is low and the yield is high, which reduces the ore loss in railway transportation and improves the effective transport capacity. Due to a higher degree of automation, it improves the work efficiency and reduces the labor intensity. At the same time, the ceramic filter pore size is small so the fine iron ore concentrate particles are blocked with high recovery rate. The filtrate is clear, so no environmental pollution and can make full use of water resources.
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2 To customize products according to the customer's special demand
3 Our company can send technical personnel to the user site to design site and the best procedure and planning.
1 Strict inspection on the products before they go out
2 To deliver the products in accordance with the contract
1 Free training technical personnel for clients
2 According to the purchase contract, our company can send technical personnel to guide installation and adjustment for free.
3 The company supplies machine parts all year round.
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5 In case of unexpected problems, they can be solved within 24 hours from the company within 1000 kilometers. For those more than 1000 kilometers, we give satisfied reply within 24 hours.
Our company's filtering equipments consist of BY type ceramic disk vacuum filters, PG type disk vacuum filters and GYW vacuum permanent filters possessing advantages of simple structures and easy operation & maintenance. They can bring customers obvious economic and social benefits.