FILTRATION PROCESS TECHNOLOGY

Transcription

1 FILTRATION PROCESS TECHNOLOGY

2 APPLICATIONS The following applications are just some of the most significant examples of DIEMME Filtration experience

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4 RESEARCH AND TESTING Experience and Knowledge, Developed since 1923 RESEARCH AND TESTING DIEMME Filtration carries out research and testing in their laboratory, specialized to the requirements of the delicate solid-liquid separation process. In this way, our customers benefit from our extensive knowledge and experience which has been growing every day, since The testing, which is carried out by a team of chemists and engineers alongside the customer s technicians, is designed to determine the filtration parameters of the tested materials, in order to assure the optimization of the customer s production process and the performances of the equipment supplied by DIEMME Filtration. PILOT PLANTS DIEMME Filtration has different solutions for the execution of filtration tests, both in its laboratory and at the customer s site. It is possible to employ one of the following models, dependant on the characteristics of the product to be tested (concentration, ph, density, etc ) and the required operation modes: desk unit in AISI 316 stainless steel, thermo-controlled, model IFP INOX2 desk unit in AISI 304 stainless steel, model KE 200 desk unit in titanium, model IFP Ti The desk units are equipped with air compressors, thermostatic baths and thermal sleeves to maintain temperature, tanks for washing liquids, etc in order to reproduce the real process conditions accurately. Pilot units are used when it is required an extended texting and a considerable amounts of product is to be filtered. These are proper industrial plants containing a filter press, pumps, tanks, make-up and dosing systems of chemical aids, air compressors, automatic valves, ph- and flow-meters, level probes, etc in one special container. All equipment is interconnected and controlled by a PLC (Programmable Logic Controller). Three different pilot plants models are available: semi-automatic plants installed on skid, model KE 500 automatic plants installed in container, model ME 630 automatic plants installed in container, model JETFILTER RH 30 After initial testing with the desk units, the pilot phase is often required, including on-site testing with industrial filter presses. In this way DIEMME Filtration can simulate various industrial process which allow them to gather accurate filtration testing results.

5 FILTRATION ANALYSIS DIEMME Filtration laboratory is equipped with the most modern apparatus to determination the parameters that are necessary for plant design. A typical laboratory test includes analysis of: sludge characterization: particle-size distribution in suspension through laser particle-size analyzer, concentration of suspended solids, value of total and dissolved solids, ph measuring, CST18 measuring, density measuring, etc ; filtration phase: optimization of the cyclogram (time, delivery and pressure), selection of the chamber thickness, the kind of plate, filtration tissue; determination of the amount of washing liquid and drying air, choice of chemical aids; filtration characterization: measuring of thickness, density, residual moisture, content of dissolved salts, resistance to fracture, etc When required, it is possible to carry out chemical stability tests on the material which may be in contact with the product to be filtered, in order to assure the suitability of the materials employed for machine manufacture. DOCUMENTATION DIEMME Filtration submits detailed documentation to the customers, including: Description of the different testing phases; Results obtained; Advised process and plant choices. Furthermore, the laboratory supplies its customers (with) a filtrate and cake sample resulting from the tests and proving the obtained results. Said samples can be useful for the customer to carry out further chemical-quantitative researches or analysis. All results are held on our company database.

6 ANALYSIS CASES DIEMME Filtration filter presses are unique models, adaptable to all industrial processes HIGH TEMPERATURE METALLURGICAL CHEMICAL AND PHARMACEUTICAL When treating very viscous products (for example in oily phase) filtration takes place at high temperatures (>100 C). In such cases DIEMME Filtration makes adaptations such as: Use of PVDF plates (Polyvinylidene Fluoride) with Viton membrane Injections of hot water inside the plates in order to control temperature and avoid thermal shocks Employment of PE (Polyester) cloths with Viton rubber lined edges Installation of suitable devices in order to assure the process safety through the check of working parameters (temperature and pressure transducers). The picture shows a membrane filter model ME 800 press installed in France, for the hot purification of three different kinds of polyoils, each with different process viscosity and temperature. TOXIC METALLURGICAL CHEMICAL AND PHARMACEUTICAL In the case of filtration of products containing toxic substance, there is a possibility that harmful fumes could be released. For this application DIEMME Filtration isolates the filter press from the surrounding environment by means of suction hoods, which convey fumes away from the operator s working area. The picture shows a membrane filter press model KE 630 equipped with suction hood which is installed in Russia, for the treatment of fumes containing arsenic in a copper refining and fusion plant. Arsenic in a dilute solution is made to precipitate as sulphide and the resulting sludge is filtered.

7 LOW TEMPERATURE In the food industry, it is often necessary to filter products at a low temperature. For this purpose DIEMME Filtration can make adaptations, such as: Piping insulation; Utilization of PP (polypropylene) and rubber lined filter cloths, which assure the plate pack tightness and reduce the heat exchange with the surrounding environment to the minimum; The monitoring and control of temperature by means of a PLC (Programmable Logic Controller) assures the correct process functioning. ALIMENTARY The picture shows a membrane filter press model ME 1000 installed in Spain, for the filtration of alcoholised white wine with potassium bitartrate in suspension. The product enters the filter press at the temperature of -13 C and comes out at the temperature of -7 C. The filter press is manufactured with materials in conformity with FDA (Food and Drug Administration) rules. EXPLOSIVES Filter presses working in the chemical, petrochemical and pharmaceutical sectors must often be equipped to work in zones classified as explosion risk areas. Some of the specialised features available include: Design of a suitable frame for earthing electric charges. Utilization of plates that are made of a polypropylene and carbon mixture, in order to avoid the forming of electrostatic charges; Utilization of cloths equipped with conductive fibres, in order to allow the earthing of electric charges; Installation of valves, electro valves and certified instrumentation to be installed in the zone that has been classified by the provisions; Utilization of aluminium-free paint; Utilization of plastic materials at low conductivity. METALLURGICAL CHEMICAL AND PHARMACEUTICAL The picture shows a membrane filter press model AUTOMAT 800 that is installed in Italy, for the filtration of crystallized medicine suspended in pure acetone. Both the washing and drying phases for the acetone recovery are carried out inside the filter press.

8 ANALYSIS CASES CORROSIVES METALLURGICAL CHEMICAL AND PHARMACEUTICAL When metals are refined, it is necessary to treat suspensions with very low ph values. In those cases DIEMME Filtration designs filter presses makes some additional adaptations, including: Headers protection through PP (polypropylene) sheets that are fixed by means of sleeves of the same material Utilization of cloths, piping and valves of polypropylene or plastic material Utilization of special epoxy paint, in order to protect the frame from chemical aggressions Drip-tray protection through polypropylene coatings or epoxy-tar painting Installation of Viton ae o-rings and gaskets The picture shows, on the left, the header of a GHT 4X with polypropylene piping and, on the right, a membrane filter press model KE 500 with polypropylene linings. These machines which are installed in South Africa, are treating sludge coming from the leaching of raw material containing platinum, palladium, rhodium, gold, nickel, copper and ruthenium, with hydrochloric acid. CHEMICAL AND PHARMACEUTICAL CERAMIC, GLASS AND CRYSTAL COLLOIDS To treat products with very low filterability and when detachment from the filter cloth is difficult, DIEMME Filtration manufactures a highly innovative filter press - the JETFILTER - with the following characteristics: Feeding plate by plate by means of injectors Reduced chamber thickness Simultaneous plate pack opening and cloth moving from top to bottom for cake discharge Cleaning bar to assure the automatic cake discharge from the cloths Washing bar with high pressure water, to eliminate any eventual cake residual from the cloths. The filter press shows filter press model JETFILTER RH70 installed in Italy, for the filtration of ceramic barbotine. MUNICIPALITY

9 LOW CONCENTRATION In case of polishing, when the product to be filtered has a very low suspended solids concentration, the main objective is to obtain an extremely pure filtrate. DIEMME Filtration utilizes the following technical devices: Creation of a fossil meal layer (precoat) on the cloth, in order to make sure that the resulting filtrate is completely free from solids, from the beginning filtration seconds Fossil meal dosing in line, in order to facilitate the percentage of solids capture Utilization of plates and frames with very thin chamber and paper or cardboard filtering elements The picture shows a plate and frame filter press model KE 630 of AISI 316 stainless steel and paper filtering elements that is installed in Australia, for the purification of additives in a PVC (Polyvinyl chloride) production plant. METALLURGICAL CHEMICAL AND PHARMACEUTICAL ALIMENTARY ABRASIVES In the mining sector (for example Cu, Zn, Pb, Fe etc concentrates) the sludge to be filtered has usually a high abrasive property, a very good filterability and a high feed rate, due to the high concentration. Therefore, DIEMME Filtration adopts some particular devices, such as: Utilization of filter cloths with special fibres of high mechanical resistance Utilization of special valves, made of anti-abrasive materials Feeding pipe flushing, to eliminate the risk of sedimentation and obstructions Utilization of hardened centrifugal pumps MINING QUARRIES The picture shows a membrane filter press model GHT 4X installed in Russia, for the filtration of concentrates from flotation in a gold refining and beneficiation plant.

10 U% PROCESS TECHNOLOGIES In connection with the characteristics of every single industrial process DIEMME Filtration adopts the following technologies: MEMBRANE PLATES U c % U m % t m t c t The membrane technology refers to a particular kind of plates, called membrane or variable volume plates. These filtering elements are able to change their volume through the injection of water or air, which is pumped inside the membrane by a suitable hydraulic plant. The raised plate volume very rapidly increases the pressure on the cakes, which were formed inside the chambers. In this way, the resulting filtration cycle time and residual moisture values in the cake are lower than the traditional technologies with recessed plates. MEMBRANE PLATE RECESSED PLATE U% = Percentage moisture t = Cycle time U c % = Moisture with recessed plate U m % = Moisture with membrane plate t m % = Cycle time with membrane plate t c % = Cycle time with recessed plate S% F1 F2 IL I1 I H2 O% CAKE WASHING S D % FL DIEMME FILTER PRESS WITH AUTOMATIC CAKE WASHING FILTER PRESS WITHOUT WASHING WITH REPULPING tl t1 S% = sali residui percentuali IH 2 O% = litri di acqua spesi t = tempo di ciclo F1 = filtration phase F2 = repulping phase FL = washing phase SD% = required percentage of Salts IL = litres of water used with DIEMME filter I1 = litres of water used with repulping tl = Cycle time with DIEMME filter press t1 = Cycle time with repulping t The solid cakes, which formed inside the plate pack, are sprinkled with a water flow in different directions: equi-current, counter-current and crossed. This system allows uniform washing of the cake and reduces the percentage of residual salts in the solid phase to the minimum. This represents a more advantageous alternative than the traditional repulping because it reduces both cycle time and water consumption.

11 CAKE DRYING The solid cakes, which were formed inside the plate pack, are crossed by a compressed air flow that is distributed in multiple directions: in equi-current, in counter-current and crossed. This system allows the cake to dry uniformly and reduces the percentage of residual moisture to the minimum, with lower energy consumption than the traditional dryer technologies U D % U% Fs F1 F2 E1 E2 E t1 t2 t U% = percentage of moisture E = used energy t = cycle time F1 = filtration phase F2 = drying phase with Dryer FS = air insufflation phase E1 = consumed energy with DIEMME filter press E2 = consumed energy with Dryer t1 = cycle time with DIEMME filter press t2 = cycle time with Dryer UD% = required percentage of moisture DIEMME FILTER PRESS WITH AIR INSUFFLATIONS FILTER PRESS WITHOUT AIR INSUFFLATIONS AND DRYER AUTOMATIC CLOTH WASHING Cloths are a fundamental filtering element, and the functioning of the filtration process depends on them. For that reason DIEMME Filtration installs the automatic cloth washing system on its machines to assure that optimum filtration performance is maintained over the life of the filter cloths. t1 t2 t P 2 N1 P1 N2 N = Cloth filtration performance t = working life of cloths N = number of filtration cycles P1 = cloth replacement due to obstruction P2 = cloth replacement due to wearing t1 = Lifetime without washing t2 = Lifetime with washing N1 = Number of cycles without washing N2 = Number of cycles with automatic and manual washing la: FILTRATION PERFORMANCE CLOTHS WITH DIEMME AUTOMATIC WASHING lm: FILTRATION PERFORMANCE CLOTHS WITH MANUAL WASHING 1: FILTRATION PERFORMANCE CLOTHS WITHOUT WASHING TECHNOLOGY

12 SALES AGENT S STAMP DIEMME S.p.A. reserves the right to bring any alteration at any time which is deemed to be necessary in order to improve its production DIEMME S.p.A. Via Bedazzo, Lugo (RA) - Italia Tel Fax filterdiv@diemme-spa.com