Helvess Limited Company is ready to develop, supply and implement innovative technologies of global manufactures of filtering equipment for agricultural, chemical and metallurgical industries.
Filtering is a process of nonhomogeneous substances separation during which the substances go through a baffle that retains one phase and passes the other.
Filters classification:
| According to operation principal and filtering element design | Vacuum filter disk filer, bag-type filter, drum filter, belt filter, etc. |
Pressure filter filter press, cloth filter, cartridge filter, etc. |
| According to the cleaning method | Liquid mixtures filtration sedimentation tanks (sumps), hydrocyclones, centrifuges, filters, etc. |
Gas systems filtration cyclones, dust collectors, bag filters, precipitators, etc. |
| According to drain type | Open | Closed |
Use of filters and cleaning systems:
Water treatment for drinking and household needs
Domestic filters
Food production industry
Textile industry
Pharmacy
Pulp and Paper industry
Greenhouse farming
Ventilation and air-conditioning
Glass-making
Chemical industry
Metallurgy
Filters and filtering systems examples
Drum-type vacuum filter
Vacuum filter with rotating drum:
- Operation is based on the vacuum function of retention of solid particles on the filtration surface. Filtrate passes through filter system and is discharged by pipelines
- Drum rotation speed is adjusted by the variable frequency drive
- Mixing excludes sedimentation
- Drive feed voltage 380 V 50 Hz
Main technical data:
| Drum diameter: | 2600 mm. |
| Width: | 2610 mm. |
| Filtering area: | 20 m.2 |
| Rotation speed: | 0.2~1 rpm. |
| Mixing frequency: | 18 times/min. |
| Main drive power: | 3 kW. |
Disc strainer for wastewater treatment
Filter is equipped with a shaft with filtering discs. The discs consist of 12 individual segments. The shaft with discs equipped with filtering cloth is suspended on two belts. The filtering cloth makes a barrier for a water flow. Contaminants are retained on the cloth and are then discharged by means of flushing system.
Flow rate: 125 l/s
Filtering cloth: 10 micron
Disc filters are suitable for undissolved substances removal in municipal and industrial wastewater treatment units. Besides, they can be used in fish farming, food and paper industries.
Two-stage centrifuges
Two-stage centrifuge with pushing pistons is an automatic continuous filtration centrifuge with constant feed.
It has such advantages as continuous automatic operation, low labour intensity, competitive price and high capacity. So this type of centrifuges is widely used in many industries for separation of liquid and solid substances.
Two-stage centrifuge with pushing pistons is mainly used for separation of suspension with medium size solids (>0.1 mm) in high concentration (>30%). The larger the crystal size and the higher the solid content, the higher the performance and better the separation effect. Separation effect and capacity depend on the crystals size and solids content and the larger they are, the higher are separation effect and capacity.
Operation principal
As soon as the drum reaches full rotation speed suspension is fed into a distributing disc through a feeding pipe and is evenly distributed on the filter screen of the drum. Influenced by centrifugal force, the liquid passes through the filter screen and holes in the drum walls and the solids settle on the screen forming a ring of filter cake. When rotating the first stage drum continuously reciprocates in axial direction. When the drum moves forward suspension is fed to form a cake ring. When the drum moves back cake moves forward along the axial direction of the drum and is fed into the second stage drum.
In the second stage drum, the loose filter cake is again distributed over the screen, washed if necessary, then is pushed into the cake collection chute and is removed from the centrifuge by gravity.
If filter cake needs flushing, flushing liquid is evenly fed inside the centrifuge through a flushing pipe. Filtering liquid and flushing liquid are collected in the housing and are then drained through a hole for liquid outlet. If necessary, filtering and flushing liquids can be separated.
Centrifuge drums are driven by an electric motor with the help of a V-belt transmission. The reciprocating motion of the first-stage drum is carried out by a compound oil cylinder through a hydraulic system.
| Drum inner diameter | 918/1000 mm |
| Filtering area length | 325/325 mm |
| Drum rotation frequency | 950 rpm |
| Separation factor | 505 |
| No. of pushes per minute | 30-75 (adjustable) |
| Push stroke | 70 mm |
Decanter centrifuge
Decanter centrifuge consists of a drum, a screw, a planetary differential, a bearing seat, feeding pipe, base. The centrifuge consists of a housing, main motor, auxiliary motor, electric control system and various control instruments. When the material enters the centrifuge drum cavity which is driven by the high-speed rotating drum, so the material will be influenced by b centrifugal force. Due to the high density of solid particles in the mixture the centrifugal force is also high, so the solid phase will be thrown off and stick to the inner wall of the drum to form a continuous annular layer.
Since the rotation speed of the screw and drum are different, there is relative motion between them, so the screw will push the solid deposited on the inner wall of the drum to the outlet of the drum small end and discharge it, and the liquid phase will be discharged from the rotating drum.
Manufacturing technology and standards
Drum: Drum material — SS316L. Drum inner surface is equipped with longitudinal wearproof bands of SS316L. This design can effectively prevent wear of the drum inner wall and increases the drum service life. It is also more conducive to solids removal.
The solids outlet at the small end of the drum is lined with a replaceable wear-resistant ceramic sleeve, preventing wear of the solid material at the slag outlet of the drum and extending drum service life. The drum design uses finite element modeling and design optimization, taking full account of key parameters such as structural strength and vibration.
Screw: Screw material — SS316L. All spiral blades are installed and welded by means of hot pressing, the process that ensures compliance with the requirements to strength and accuracy during spirals manufacturing.
The upper end of the spiral feed cavity is designed with a conical structure to reduce the rebound of material after impact, improve processing performance, and avoid the spiral clogging and blocking of the feed tube. The screw shall also undergo solution treatment and stress relief heat treatment to ensure its strength and stability over time. The spiral has an estimated service life of 25 years, and the factory dynamic balance accuracy is G2.5.
Base: Base is made of SS304 and fully welded. During engineering process, the optimized structure is obtained by simulation and finite element modeling, that is, the vertical optimized structure. This structure guarantees to withstand all overhead dynamic loads as well as effectively reduce the vibration generated during machine operation. The base of the machine is connected to a shock absorber, which can be easily mounted on the concrete base directly.
Main bearing: The main bearing of the large end of the drum is cylindrical roller bearing, which ensures that the equipment can safely operate at high speed for a long time and withstand heavy loads.
Sea water desalination complex
Technology development and expansion in water demineralization and reuse grows up gradually to a paramount challenge worldwide. The situation with fresh water shortage is getting worse every year against the backdrop of growing industrial and public needs aggravated by insufficient number of deep treatments stations.
The water recycling and treatment market includes three major areas:
- desalination of seawater and other salt water for use in agriculture or to meet human personal needs;
- water reuse: filtration and disinfection of wastewater;
- industrial use, where huge quantities of water are required for operation.
Strict government requirements oblige industrial facilities to treat the water they use to acceptable levels and that is the one of the main drivers of the water treatment industry. Extensive economic development and the increasing urbanization rate of the world's population, especially in developing countries, are the additional incentives for finding effective solutions in this area.
One of the most well-tested processes in this area is reverse osmosis, it involves pumping pressure water through semi-permeable membranes that allow water molecules to pass through and retain dissolved substances. The output is a permeate, a filtrate that is virtually free of salts, and a saturated aqueous solution of salts.
Reverse osmosis is currently considered to be the best water demineralization method available on the market. This technology shows high efficiency, it is less energy-consuming and requires less industrial space than equipment for other desalination methods.
The system consists of the following process units:
- seawater pre-treatment, including:
- dissolved air flotation (pressure flotation);
- sump with pre-treated seawater
- seawater disinfection system
- multilayer filtration system
- cartridge filtration
- two-stage reverse osmosis unit;
- Feed: sea water
- Capacity: 300 m3/hour (desalinated water);
- Operation mode: continuous (round-the-clock);
- Composition of sea (feed) water:
| Parameter | Value |
| Total hardness | 78 mg-equ/L |
| Alkalinity | 3,5 mg-equ/L |
| Total ferrum (Fe) | 0,0000059% (0,06 mg/l) |
| Sodium (Na+), Na+K | 0,336% (3430 mg/l) |
| Calcium (Ca2+) | 0,0333% (340 mg/l) |
| Magnesium (Mg2+) | 0,0757% (773 mg/l) |
| Copper (Cu2+) | 0,00000049% (0,005 mg/l) |
| Ammonium (NH4+) | 0,0000157% (0,16 mg/l) |
| Nitrite (NO2-) | 0,00000196% (0,02 mg/l) |
| Nitrates (NO3-) | 0,000041% (42 mg/l) |
| Chlorides (Cl-) | 0,5296% (5407 mg/l) |
| Sulfates (SO42-) | 0,3362% (3433 mg/l) |
| Dry residue | 1,303% (13300 mg/l) |
- Required quality of desalinated water:
| Parameter | Value |
| рН | 6 — 9 |
| Salt content, max | 3,0 mg/dm3 |
| Oxidizability, max | 2,5 – 3,0 mg/dm3 |
| Hardness | — |
| Chlorides, max | 0,2 mg/dm3 |
| Sulfates | — |
| Ferrum, max | 0,02 mg/dm3 |
| Silicic acid, max | 0,1 mg/dm3 |
| Specific conductivity, S/cm | ~2*10-6 |
| Temperature | 15-30°С |
Application of pre-treatment system:
- reduction of the amount of solids contained in seawater;
- reduction of the amount of organic substances contained in seawater;
The raw seawater enters the flotation unit with dissolved air. Preferably, the flotation unit is located adjacent to a concrete sump with pre-treated seawater. The capacity of the dissolved air flotation unit for untreated seawater is 600 m3/hour.
The seawater is treated with reagents for pH correction and, if necessary, with a flocculant (e.g. ferric chloride).
The reagent-treated seawater flows by gravity from the flocculation tank into the flotation tank. It enters via a feed pipe located in the lower center section, together with recycled water supplied from the pressure tank. The accumulation of the water-air mixture results in the formation of very fine air bubbles which, as they move upward, hold all particles on the surface, including oil and grease. These materials remain on the surface of the tank as scale and they are removed by a surface skimmer.
Seawater disinfection system
Sodium hypochlorite is fed into the sump to disinfect pre-treated seawater. Sodium hypochlorite has an antiseptic disinfectant effect. It is as effective as chlorine, but is completely non-toxic at low concentrations, which makes sodium hypochlorite safe for water desinfection. Compared to liquid chlorine, sodium hypochlorite has a much lower environmental impact, which means that the use of sodium hypochlorite is environmentally friendly.
The sodium hypochlorite dosing system consists of:
- 1 m3 storage and dosing tank;
- dosing pumps (2 pcs. — 1 working and 1 standby);
- level sensor to protect pumps from dry running;
Multilayer filter system
Seawater treated with sodium hypochlorite is fed to the multilayer filters by feed pumps (4 in operation and 1 standby). Each pump is equipped with shutoff valves (suction and discharge) and a check valve on the discharge. The filters are tanks with all necessary piping, measuring and control equipment. Sand (total volume about 30 tons) and anthracite (total volume about 15 tons) are used as filter filler. The multilayer filters are equipped with automatic two-position valves.
The filter piping and valves are made of polyvinyl chloride. A flow sensor and conductivity sensor are installed on the piping of the multilayer filters.
The multilayer filters have an automatic backwashing system (water + air) consisting of a concrete tank, a backwash pump and an air blower. The water source for the backwashing system is filtered sea water, which is stored in a 130 m3 concrete tank. The tank is equipped with a level sensor.
Cartridge filtration
After the multilayer filters the filtered water flows to the cartridge filters (3 in operation and 1 standby). Cartridge filters provide additional protection of membrane units from fine suspended solids. At the same time, an antiscalant from the dosing system is added to the water before it is fed to the cartridge filters. The antiscalant reduces the formation of hardness salts and iron precipitation on the membrane surface, it significantly extends the life of membrane elements.
Antiscalant dosing system consists of:
- 1 m3 storage and dosing tank;
- dosing pumps (2 pcs. — 1 working and 1 standby);
After the cartridge filters the water is additionally treated with a reagent thar removes chlorine (sodium bisulfite). Sodium bisulfite deactivates chlorine contained in sea water, which prevents reverse osmosis membranes from being destroyed.
The water treated with sodium bisulfite is fed to a two-stage reverse osmosis unit.
Automatic membrane filter press
| Name | Parameter |
|---|---|
| Material names | ferric hydroxide and hydroxyphosphate, gypsum and carbonate slurry |
| Capacity of 1 filter press | 30 m3/h |
| Solids content at slurry feeding | — electric conductivity: max 15000μSm/cm — oil products: max 60 mg/l — chlorides: max 5000 mg/l — sulphates: max 5000 mg/l — salts content: max 10 g/l — suspended solids content: 350-20000 mg/l (0.035-2%) — solids type: ferric hydroxide and hydroxyphosphate, gypsum and carbonate slurry |
| Temperature | from +15 up to +35 °C |
| Ph value | 5.5-12 |
| Solids size | up to 1.0-2.0 mm |
| Cake moisture | ≤ 20% |
| Effective filtering area | 210 m2 |
| Filter chamber total volume | 4 m3 |
| Filter plate size | 1250*1250*7mm (L*W*H) |
| Filter plates quantity | 78 pcs. |
Vacuum belt filter
Belt filters are designed for dewatering of residential and industrial wastewater. Belt filters are applied in the following industries: metallurgical, food, pulp and paper industry, public utilities.
Technical description
| Filtering surface | 2.5 m2 |
| Belt width | 1300 mm |
| Belt movement speed | 1-8 m/min |
| Length | 8850 mm |
| Width | 1030 mm |
| Height | 1930 mm |
| Capacity | 20 m3/h |
| Electric power supply | 380V, 5Hz, 3-phase |
Cartridge filter for liquid sulphur
Cartridge filters are made of carbon mass, porous ceramics and are designed for filtration of suspensions with low content of solid phase in order to purify the filtered substance.
| Medium: | Liquid sulphur |
| Capacity: | 5 m3/h |
| Filtering area: | 6 m2 |
| Filtering accuracy: | less than 10 ppm |
| Filter casing diameter: | 880 mm |
| Tank volume: | 0.56 m3 |
Bag filter for the production of purified terephthalic acid. Industrial gas emissions purification
| Filter type | bag filter |
| Filtering area, m² | 144 |
| Filter rate, m/min | 1.07 |
| Filtering bags quantity | 40 |
| Filtering bag length, m | 2.5 |
| Filtering bag material | anti-static polyester |