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to success
since 1997
"INTECH GmbH"
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Distributor / authorized representative that deals with supply & delivery of drum filters to industrial enterprises of Russia

Engineering company ‘Intech GmbH’ LLC (ООО «Интех ГмбХ»), Russia, has been successfully working with a number of Russian industrial enterprises at the local market for more than 20 years. Since the company’s founding, it has acquired immense engineering experience, market reputation, and has realized more than a hundred large-scale projects at the industrial plants in Russia. Our company is continuously in search of new business partners, who consider Russian market investment-attractive and want to boost their sales in the region, as well as expand their field of activities and enter a new international level.

We are interested in cooperation with the manufacturers of drum filters, who are looking for an official and reliable distributor to deal with supply & delivery of their equipment to the industrial plants in Russia.

The company’s top management and sales team are well acquainted with the Russian market, its mentality and laws; they also understand industrial specifics of the financial and economic activities of the Russian customers. All our sales managers have a large customer database, extensive experience of successful sales and well-established connections with the potential buyers of your drum filters. This allows our managers to promptly set out the most promising directions for promotion and to ensure a rapid entry of the products into the promising Russian market. Our employees, who are fluent in English and German, are focused on working at the international market with the supplies of foreign equipment.

Our team of experienced engineers, who can handle the most serious technical problems, constantly keeps in touch with the Russian customers, holds meetings and delivers presentations regarding the latest achievements of our manufacturing partners. They point out the engineering challenges and actively communicate with all the departments at Russian plants. That is why the specifics of doing a business in the Russian Federation are well-known to us, and we also know the equipment of the local industrial plants and their up-to-date modernization needs.

Once we become your authorized representative in Russia, our marketing staff will carry out a market research in order to check the demand for drum filters, will submit a market overview for drum filters that you offer and evaluate the needs for this type of equipment at local plants. Our specialists will also estimate the potential and capacity of this market at local industrial plants. Our IT-team will start developing a website for your products in Russian. Our experts will assess the conformity between your drum filters and customer needs as well as analyze the common reaction to the new goods in general. We will look into the categories of potential customers, and pick out the largest and the most promising plants.

Upon becoming your authorized agent on the territory of Russia, ‘Intech GmbH’ LLC (ООО «Интех ГмбХ»), will obtain certificates, if required, for a batch of the goods, for various types of drum filters in compliance with Russian standards. We can also arrange the inspection in order to obtain TR TS 010 and TR TS 012 Certificates. These certificates provides permission to operate your equipment at all industrial plants of the EAEU countries (Russia, Kazakhstan, Belarus, Armenia, Kyrgyzstan), including the hazardous industrial facilities. Our company is eager to assist in issuing Technical Passports for drum filters as per Russian and other EAEU countries’ requirements.

Our engineering company ‘Intech GmbH’ LLC (ООО «Интех ГмбХ»), collaborates with several Russian design institutes in various industrial segments, which allows us to conduct preliminary design as well as subsequent design works according to the standards, construction rules and regulations that are applicable in Russia and other CIS countries. It also enables us to include your drum filters into the future projects.

The Company has its own logistics department that can provide packing service, handling as well as the most efficient and cost effective mode of transportation of the goods (incl. over dimensional and overweight goods). The goods can be delivered on DAP or DDP-customer’s warehouse basis in full compliance with all the relevant regulations and requirements that are applicable on the Russian market.

Our company has its own certified specialists who will carry out installation supervision and commissioning of the delivered equipment, as well as further guarantee and post-guarantee maintenance of drum filters. They will also provide necessary training and guidance for the customer’s personnel.

Drum filters. A brief overwiew

General description of drum filters with an external filtering surface

Drum filters with an external filtering surface belong to continuous rotary filters. They have a rather simple design while ensuring reliable operation; these are one of the most commonly used filters in industry.

A horizontal rotating drum is the basis of the unit. Longitudinal ribs are located at its lateral surface. The drum is covered with a filter membrane. Here, isolated compartments are formed due to protrusions between the drum surface and the membrane. Each compartment contains discharging tubes passing through the distribution head. The distribution head is fixed rigidly and connects the tubes with the vacuum line and the compressed air line.

The drum is mounted over a trough where suspensions are fed. A mechanical agitator is provided to prevent solid particles settling. The drum is partially immersed in the suspension during operation. When the drum is rotating, each compartment passes through all operations during each revolution.

Filtering starts when a compartment is immersed in the suspension. The compartment is vacuumed and the filtrate penetrates through the membrane and is further discharged into a prepared tank through the distribution head fitting. The cake is formed on the filter membrane surface in the area of this compartment. After leaving the suspension, the compartment is vacuumed again to remove residual filtrate from the cake. Then the cake is washed and dewatered again. During these operations, the compartment is also connected to the vacuum line. Air and moisture particles are discharged through a special fitting. The next operation is cake loosening by feeding compressed air through the special fitting into the compartment. After loosening, the cake can be easily scraped from the filter membrane with a knife or any other device.

Some filter models allow filter cloth regeneration. In this case, the compartments are blown through with compressed air or steam supplied through the fitting. This is how residual solid particles are removed from the filter cloth.

Design of the vacuum drum filter

The drum is a horizontal metal cylinder having flat end walls with ribs on their inner side. Pivots are bolted to the walls and placed into bearings which are fixed on the frame of the unit. The distribution head is connected to the left pivot. Tubes connecting the distribution head with the drum compartments pass through the pivot. A gear wheel is located on the right pivot and is used to transmit rotation from an electromechanical drive to the drum. The agitator is hinged to the both pivots and is driven by a crank mechanism and an agitator drive. The filter frame supports the load due to all assemblies and the processed suspension weight.

The tank (trough) for suspension, pipeline trusses and knife for cake scraping are fixed to the filter frame. Longitudinal ribs welded to the lateral surface of the drum divide it into compartments. The compartments are covered with a drainage material – a perforated sheet or a polypropylene mat. The mat is made as a lattice. Cloth lies on the upper longitudinal rods of the lattice while its lower transverse rods rest on the drum ribs.

The drum is covered with filter cloth fixed in the grooves of the ribs with a rubber cord. A 2-3 mm wire is winded over the cloth. The wire is wound using a stationary device consisting of a guide screw fixed in the supports, a slide with guide rollers and a drive. One end of the wire is connected to the drum and makes the roller engaged with a nut rotate due to the acting friction force. The nut induces translational motion of the slide.

Distribution head

The distribution head includes a housing which is located on the axis fixed on the drum pivot. A bearing on the axis reduces friction losses. The end of the pivot and the housing are connected by two washers. А filter cell is fixed to the end of the pivot. The number of holes in the cell equals to the number of those in the drum cell. A head body with different-sized annular slots corresponding to those of the head is attached to the head. Two large cavities include fittings connected to the vacuum line. Two small cavities include fittings connected to the compressed air line. Springs at studs force the distribution head housing against the pivot. The studs are screwed into the bearing housing. The distribution head is equipped with a vacuum gage.

Two washers of the distribution head are made as an antifriction pair (steel – cast iron, steel – plastic with graphite, steel – bronze, etc.). Washers shall be wiped prior to be installed in the filter. The springs create the pressure of 0.1 – 0.2 MPa between friction surfaces.

Agitator

The agitator is designed as a detachable unit. A lattice frame having the same shape as the trough serves as the base for the agitator and is fixed to detachable flanges by rods. Several rollers of the flange rest upon the filter drum pivot. For uniform load distribution between the rollers, one of them is located on the eccentric axis. Agitator drive connecting rods are hinged to the flanges. The agitator average speed is 0.3 m/s.

Application of vacuum drum filters

Vacuum drum filters are commonly used to separate suspensions with solid particles of approximately the same size, their concentration of above 5%, and the settling rate of up to 0.012 m/s. Pressure difference in such filters varies from 0.02 to 0.09 MPa depending on the suspension properties. Drying and washing of the cake is of high quality. Parameters for selection of vacuum filters: filtering surface, drum diameter, drum speed, etc.

Use of vacuum drum filters:

  • High rate of particle settling. Vacuum drum filters with an external filtering surface are used to separate suspensions when solid particles settling rate does not exceed 18 mm/s. An agitator is installed in the bath to prevent settling of the solid phase. However, its speed should be low enough; otherwise, the cake will be washed off from the filter membrane.
  • Small cake thickness. These filters are designed for products with a solid phase allowing to obtain at least 5 mm cake within 4 minutes when the compartment is immersed in the suspension. In such filters, the suspension is filtered with a low rate. The drum makes a full revolution during 0.5-10 min. If the cake has thickness below 5 mm, it may be difficult to separate it from the filter cloth, because the air would pass through a too thin cake or through cracks formed therein during blowing. In addition, a thin cake may "cover" the cloth thus becoming almost hard to clean with a knife. Pores are clogged rapidly which greatly reduces filter throughput and makes its use unreasonable. That is why vacuum drum filters are not suitable for separation of suspensions with low concentration of fine particles.

Specific design features of drum vacuum filters

The described design of the drum vacuum filter is not unique. Various filters can differ in their characteristics. For example, a filter with a large filtering surface and producing significant volume of the filter will be equipped with two distribution heads. Filters can be of open design or with a hip roof or can be placed in a sealed tank. Not only a knife, but also a roller can be used to remove the cake. In addition, filters with belt discharge are available, requiring no special mechanisms to remove the cake.

Cake removal with a roller

Filters where the cake is removed with a roller are usually used to separate difficult-to-filter suspensions. When the drum passes the cake removal zone, a rubberized roller is forced against it along the drum generating line. The cake sticks to the roller to be removed therefrom with a knife. For a fibrous cake, a hollow toothed roller is used. Alternatively, the cake can be removed from the roller by blowing.

Vacuum drum belt filters

These filters are effective for difficult-to-filter suspensions where the solid phase quickly clogs the filter cloth with slurry. Filter cloth in such units is made as an endless band which covers the drum in filtration and washing zone. In the cake removal zone, the band bends around the rollers to discharge the cake. The band is washed in the next zone and goes back to the filtration zone.

Specialized design versions

Specialized vacuum drum filters are used to separate suspensions which cannot be processed by general-purpose filters due to their limitations. High speed of solid phase settling is one of these limitations. For work with compositions with the settling rate above 18 mm/s, filters with top suspension feed or with an internal filtering surface are used.

Vacuum drum filter with top suspension feed

Filtration zone in such installations is located in the top part of the drum and it occupies a small area. Filters are fitted with a device for top suspension feed.

Vacuum drum filters with an internal filtering surface

The main component of such units is a horizontal drum, closed from one side with a continuous wall, and with an annular bead from the other side. The drum surface is divided into sections from inside; a filter cloth is attached thereto. Each compartment passes through all process filtration zones during drum rotation. The suspension is supplied in the filtration zone inside the drum and fills all the bottom space to the annular bead level. Remaining filtrate is removed from the cake using compressed air in the drying zone. The cake in such vacuum drum filters is not washed. The cake in the top part of the drum is blown with air and gets to the conveyor. Then air or steam passes through the filter cloth for regeneration.

Schematic drawing of the vacuum drum filter with an internal filtering surface

Multicompartment vacuum drum filter

Multicompartment vacuum drum filters are one of the most popular filters for continuous operations in the chemical industry. Its main component is a horizontally located drum immersed in the tank (approximately 0.3 -0.4 of the surface). Drum walls are perforated and covered with a metal lattice and filter material. Drum inner space is divided into several sections by radial membranes. The drum is mounted on the shaft and rotates with the speed of 0.1 -3.0 RPM. One end of the shafts is connected to the drive, and the other one is connected to the distribution head which is rigidly fixed and communicates with all drum compartments. The head is designed as a hollow pivot with channels. Its housing is divided into chambers of different volume. Each of them is designed for a particular medium: filtrate (the largest chamber), washing liquid (medium-sized chamber) and compressed air (two small chambers).

As the drum rotates, the first two chambers are connected to the vacuum line, the rest of them are connected to the compressed air line. The suspension is supplied into the tank in which the drum is immersed. An agitator slowly rotates in the tank to prevent settling of the solid phase.

When separate drum compartments are immersed in the suspension and connected to vacuum, the filtrate is discharged through the channels and solid particles settle down on the surface of the filtering material. When compartments get out of the suspension, they remain connected to vacuum; therefore, the airflow is drawn inside with the remaining moisture from the cake. The cake is then washed and the liquid is discharged via channels in the distribution head. Then, the cake is dried again by drawing air inside. Then the compartments are connected to the compressed air line which separates the cake from the filter cloth and loosens it. The compartments are detached from the cake removal line and connected again to purge the filtering material. Then the compartment is immersed in the suspension and the cycle is repeated.

Calculation of drum filters

The primary filtering system consists of units and facilities for mechanical removal of the largest and heaviest contaminants from wastewater. Sand catchers, grates, flotation units and other methods of mechanical treatment allow for removal of impurities which impede normal operation of the cleaning equipment at later stages.

The mechanical cleaning of wastewater is followed by primary filtration (clarification) by stationary vertical, horizontal and radial filters. They separate the major mass of clarified water which is later sent to the second stage, i.e. biological cleaning. It is the remaining content of stationary filters that requires further processing.

In order to dewater suspensions, discharge the required components and subsequently process the cake, centrifuges, cyclone separators and filters are used. Continuous filters, such as disk, band and vacuum drum filters, are the most effective. The most efficient type of filters used in the chemical industry is the vacuum drum filter. In this filter, suspension is separated into light (centrate) and heavy (cake) fractions through its external filtering surface, which ensures easy maintenance of the unit.

The duration of the entire cycle of the vacuum drum filter is expressed using the drum rotation frequency:

τcycle = 1/n

where τcycle is the time of the entire filter cycle, s;
n is the drum rotation frequency, s-1.

The required filter is determined by the formula:

F = (Q·τcycle) / (υfsp·Kcor)

where F is the required filtration zone, m2;
Q is the specified performance for the filtrate, m3/s;
τcycle is the entire filter cycle, s;
Kcor is the correction factor with account for the required increase of the filtering surface due to the increase of filter membrane resistance after its long use (Kcor= 0.8);
υfsp is the specific filtrate volume, which can be defined by the formula:

υfsp = hcake/x0

where hrl is the height of the filter cake layer, m;
x0 is the ratio of the filter cake volume to the formed filtrate volume.

Drum wire mesh filters

Drum wire meshes with bactericidal lamps are used at aeration stations instead of primary settlers for mechanical treatment of domestic wastewater. This type of filters is used for catching of coarse impurities if the concentration of suspended solids in the wastewater does not exceed 250 mg/l.

Application of drum meshes with bactericidal lamps for cleaning of domestic wastewater with such contamination allows to reduce coarse impurities content by 20-25%. However, waste water should be free from any viscous substances, such as bitumen or resins that impede wire mesh washing.

The main part of this unit is the welded drum with filter elements located on its surface. The drum rotates due to the drive which includes a motor and a gearbox. The tube, which is the drum rotation axis, also serves as a collector for discharging of wash water captured by funnels inside the drum. Wastewater enters the unit through the wall of the drum. Purified water is discharged radially after it is filtered through the mesh, and then it is sent to the discharge channel through the unit chamber.

Impurities are discharged not only during mechanical draft in the mesh cloth but also due to their detention in the cake formed on the mesh. The mesh is washed with water jets from plate sprinklers located underneath.

Main technical characteristics of drum meshes with bactericidal lamps

Mesh elements may include two meshes: working and supporting ones. The working mesh is made of stainless steel, nylon 6 or brass, while supporting meshes are made of brass or stainless steel with 2·2 to 8·8 mm compartments.

The drum located in the chamber is immersed into water for 0.85 of the diameter. When drum meshes are combined with bactericidal lamps, regular washing is required. In this case, head loss at the micromesh should not exceed 0.1 m. For outgoing utility lines and for water discharge backing, the head loss is determined by calculation and should not exceed 0.5 m - 0.6 m. Water consumption necessary for the LRU washing is about 1-1.5 of performance rate of the unit.

After LRU washing, contaminated water is supplied to the settler for up to one hour. The resulting cake is sent for further processing with all residues from treatment facilities.

To prevent mesh fouling, the drum surface is radiated with special bactericidal lamps. The number of backup meshes is calculated depending on the number of operating units. For 1-5 units one mesh is enough, for 6-10 units two meshes are required, for 11 and more units three backup meshes are required.

These filters are installed in chambers with a water drainage wall, providing design immersion of the drum into wastewater. The distance from the drum to the chamber walls should be at least 0.5 m-0.7 m, with 0.8 m – 1 m from the end bearings to the chamber walls, and 0.4 m - 0.5 m from the chamber bottom to the drum. If there are more than five units, they are usually located in the chamber in pairs.

Mesh drum filter

Filters

Upon becoming the official distributer of fabric filters, our company ‘Intech GmbH’ LLC (ООО «Интех ГмбХ»), carries out the following: finds the buyers of your products on the market, conducts technical and commercial negotiations with the customers regarding the supplies of your equipment, concludes contracts. Should a bidding take place, we will collect and prepare all the documents required for the participation, conclude all the necessary contracts for the supply of your equipment, as well as register the goods (fabric filters) and conduct customs clearance procedures. We will also register a certificate of transaction (Passport of Deal) required for all foreign trade contracts in the foreign currency control department of the authorized Russian bank so that currency transaction could be effected. If required, our company will implement an equipment spacing project in order to integrate your equipment into the existing or newly built production plant.

We are convinced that our company ‘Intech GmbH’ LLC (ООО «Интех ГмбХ»), will become your reliable, qualified and efficient partner & distributor in Russia.

We are always open for cooperation, so let’s move forward together!