Disk vacuum filters DOO are designed for separation of suspensions with the up to 70% content of solid phase with up to 5000 kg/m3 of solid phase density and for suspensions which are forming crack-free deposit and deposit which does not require flushing.
The unique design of disc vacuum filters DOO consists in a large filter surface, at comparatively less required space. It provides filters DOO with the highest performance.
Moisture of produced cake, depending on the properties of the suspension (particle size), and provided by appropriate addition of reactants can reach 8,7-9,0% performance from 400 to 2000 kg/m2 filter area. This the filters can be used for filtration of iron concentrate after wet magnetic separation, mineral concentrates obtained by flotation and gravity separation.
The temperature of the slurry for the filter made of carbon steel – 2-60 °C, of stainless steel – 2-95 °C.
Disk sectors can be made from the following materials: steel, galvanized steel and stainless steel, titanium and plastic.
In agreement with the customer we can supply accessories: receiver-traps, diaphragm valves, liquid ring vacuum pumps, blowers, filter covers, valves, instrumentation tools, weight meter, etc.
For the organization of the steam drying of sludge, filters can be equipped with a tent roof (steam hood).
New disc vacuum filters”DOO” with the casted iron shaft
with increased cross-section.
Our specialists have designed a new disc vacuum filter with a tubular shaft and cast iron shaft with enlarged cross-section (this characteristic is specified in the designation of the filter at the end, numbers “04”), filtration surface area of 200 m2.
Increased cross-section of these shafts, as well as the distribution heads, washers, cellular and dis-tribution gaskets and sector neck can significantly reduce the resistance on the filtrate discharge path, improve hydro-and aerodynamic characteristics of the filter, provide the optimal conditions for filtrate discharge and effective drying of the cake.
The basis for this development were the technical and technological research results of disc vacuum filters under operating conditions, as well as many years of experience in the production of disc vacuum filters DOO100 / DOO63.
Also is possible to produce disc vacuum filters DOO in the budgetary version – with a tubular shaft. This option is in addition to the relatively smaller resource of the shaft and is characterized by the low cost of its repair.
Main advantages of the filters with the casted iron shaft with increased cross-section are as follows:
• increased performance at a lower filter cake moisture;
• increased endurance of the distribution heads;
• long interrepair time.
Ergonomics of the design solutions utilized in this new development guarantees convenient access of the operation personnel to the working zone of cake removal, to driving mechanisms, lubrication units and control and measuring instruments.
Description of main units of “DOO” filters modernization:
• Casted cell shaft with the increased flow section allows larger diameter, which significantly increase the flow capacity. The filters with this type of shaft have the highest specific performance and maximum service life.
• Straight distributive head (can be with increased or with standart cross-section) is a single-piece cast construction with abrasion resistant coating. Performance of distribution heads with propulsive filtrate discharge improves the aerodynamic characteristics of the filtrate discharge (increases the capacity of water mixture through the internal channels) that based on operating experience, can decrease the humidity by 0.5%. Application of this design (eliminates turbulence inside the head) and head material (material of manufacturing – cast iron with abrasion resistant coating) can increase their service life.
• Filter bath – to prolong the lifetime is covered by abrasion resistant coating
• Sliding bearings – cast block housings with additional installation of anti-friction inner liners made of plastics.
• Rotary mixer of improved design with an improved seal bearing units and automatic control.
• Automatic centralized lubrication system of the rubbing surfaces.
• Sediment removal system – adjustable in length and the number of pulses (up to 3 times) the system of pulse stripping.
The main advantages of the sludge instantaneous pulse stripping:
a) Gentle effect on the filter cloth.
b) Reduction of air stripping.
c) Ease settings changing (quantity and duration).
d) Reduction of water concentrate (moisture, which, when the filter is removed through the inner cavity of the shaft and is in it during the short cycles of stripping does not have time to go back through the cavity of the sectors in the sediment).
e) Removal of sediment from the surface of the sector up to 99% (which affects the specific performance of the vacuum filter.)
f) Regeneration of the filtering properties of the filter cloth (covers on the sectors)
In recent time industrial companies are paying attention to process technology and final quality of the produced products. Therefore the companies are modernizing their production facilities and installing centralized control system of operating process with the option of equipment remote control. The technological characteristics are recorded and displayed on common control panel which allows to timely diagnose and correct deviations from the assigned parameters.
For this purpose our company has developed and successfully implementing new automation system of disc vacuum filters.
For today the control system can perform the following functions:
1) Automatic starting and stopping with automatic switching on and off of the vacuum and power supply / shutoff.
2) Automatic optimization of filtration, including: maintaining the level of suspension in the bath by adjusting the speed of rotation of the discs, depending on the amount of supply (in case of emergency); adjusting the amount of power supply to the filter; connection of the filter vacuum to the heads only at a given level of suspension in the bath; lock and alarm system: based on pressure and flow of water on the hydro seal, on the stop the conveyor, by the presence of the vacuum, along the lower level of the pulp in the bath, on the stop of the agitator drive, by the presence of stripping, on rotation of the disk.
3) Flexible adjustment by the operator of agitation mode of fabric covers (with adjustable time of stripping operations 0,08-3 seconds and the number of pulses 1-3 times) for adjustable instantaneous of stripping cake with automatic synchronization with the rotational speed of the cell shaft (increases performance and energy-efficiency of the filter).
4) Adjustment of the suspension volume
5) Double stage opening of slurry discharge valve from the bath.
6) Maintaining the temperature by local heating in the control cabinet.
7) Audible alarm at start-up of the filter and emergency situations.
8) Application of selfregenerating filters for sealing water cleaning (up to 50 mkm).
9) Purification of hydro seal water (up to 50 microns) of self-recovering filters.
Our lately developed automatic control system can be used for new disc vacuum filters as well as for modernization of already operated disc vacuum filters. Upon customer request automatic control system can be developed on the basis of world leading manufacturers of PLC, such a Siemens, Mitsubishi, etc. We can supply it with uninterruptible power supply 220 V, AC.
Process tasking of new automation system:
• Optimization of slurry intake – cake thickness adjustment.
• Prevention of emergencies at vacuum filter operation.
• Reduction of service operation on a vacuum filter.
• Ability to connect to upper level of automation.
• Ability to control the filter capacity.
• Ability to control moisture content of obtained concentrate.
The modernized automation system allows achieving the following:
• Increasing productivity of vacuum filter.
• Reduced moisture content of obtained cake.
• Long service life of filter cloth.
• Reduced energy consumption.
• Reducing of service time.
• Ability of commutation with shop automation of upper level.
Slurry density control (SDC)system
One of the recent developments of Berdichev Machine-Building Plant “Progress” is slurry density control (SDC) system in the filter bath. SDC system was implemented and tested at one of the iron-mining plants. The test results showed, in addition to the SDC system operability, the importance of adjusting the density of the slurry in the bath, as an important technological parameter having a significant effect on the moisture content of the concentrate. Based on the SDC system, modern filters are equipped with a patented SDS density control system that performs the slurry thinning to the operator-specified density.
The presence of the SDC system offers a new level of filtering process control (in real time with the setting of optimal values) to the technological staff of the ore-processing plants.
One more development is a patented system for controlling the state of filter cloth FCC. This system allows you to detect damages of the filter cloths and prevents the long penetration of the solid phase into the internal cavities of the filter; it prevents wear of parts and clogging of units with a solid phase.