Rubber Lining. Your guide to productive rubber lining solutions

Transcription

1 Rubber Lining Your guide to productive rubber lining solutions

2 Our solutions Our skilled staff and dialogue with the clients make us stand out from the other operators in the field. With solid knowledge of several fields, our professional staff will help you to find the best possible solution to your problem. is at its best in places where there is both mechanical and chemical strain. 2

3 Energy production Nuclear power Coal power Water treatment plants Ship building Offshore industry Chemical industry Metal industry Mining industry 3

4 General information about rubber Rubber is a process and construction material with a growing popularity. Rubber is elastic polymer material, so called elastomer, the qualities of which can be regulated according to the requirements of the product that will be manufactured from it. Basic elastomers can be categorized into natural rubber and synthetic rubbers. Natural rubber is coagulated from the milky sap or latex produced by rubber trees. This is how we get natural rubber. There are tens of different kinds of natural rubber depending on the variety of the rubber tree, preservation, drying method and purity. The methods of handling crude rubber have an effect on the qualities of the final product. Synthetic rubber is manufactured from crude oil by processing. Various basic elastomers with new and different qualities can be manufactured by cutting and joining together different kinds of hydrocarbon fibres. Rubber mixtures that contain a basic elastomer, alloy, additives and auxiliary substances are used to manufacture rubber products. The qualities of the rubber such as hardness, firmness, and chemical sturdiness can be altered by changing the mixture. The lining materials used by have either been produced by our own mixing factory or by our international partners. Rubber receives its final qualities in a chemical reaction called vulcanization. During this reaction, vulcanization substance within the rubber mixture forms double bonds between elastomer chains, bonding them together permanently. Before vulcanization, the rubber mixture is plastic mass that adapts to the shapes of even the most difficult shaped structures. Vulcanization is usually done in an autoclave. The autoclave is a pressure container, in which rubber material receives its desired qualities and a bonding between the lining material and the basic material is formed under the conditions of approximately 5 bar pressure and temperature of 140 degrees Celsius. There are also rubber mixtures that can be vulcanized in lower heat with the help of, for example, hot water or process temperature. It is also possible to use pre-vulcanized linings with which the attachment happens with a separate attaching membrane. Pre-vulcanized rubber varieties are especially popular in large scale wear protection targets. 4

5 Industrial processes utilize the chemical and mechanical qualities of rubber. Using structures with rubber lining in different fields of industry can be used as a layer preventing corrosion in targets for which maintenance free, long-term protection for either strong acids or alkalis is wanted. Especially corrosion caused by the chlorides in sea water can be effectively prevented by rubber lining. has been successfully used in as wear protection coating, especially in mining industry. The elastic qualities of rubber effectively prevent the wearing effect of different burdens towards it. The kinds of processes, where there is both chemical corrosion and mechanical wear simultaneously, can be protected by rubber lining. There are special rubber mixtures available for these targets. 5

6 Energy production Nuclear power The cooling system of a nuclear power plant requires a lot of water. This is why they are built close to water, normally by the sea. The chlorides in sea water cause corrosion problems also in welded structures made of alloy steel. We have seen in practice that structures made of normal structural steel and enforced with rubber lining suitable for the prevailing conditions can function without repair for tens of years. We in Finland have over 30 years of experience on structures with vulcanite lining. Structures with rubber lining are used in both the water cooling system in the reactor and the condensers and their pipes in the turbine plant. Materials: Vulcanites made of natural rubber or styrene butadiene rubber Hannu Huovila/TVO 6

7 Concerning structures lined with rubber, electrical energy production can be divided into two different plant types: coal burning condensate power plants and nuclear power plants. Coal power plant When burning coal, there is sulfur dioxide in flue gases. According to the environmental legislation, only certain concentrations of sulfur dioxide can be let to the atmosphere. Because of this, depending on the output of the plant, its flue gases must be cleaned effectively enough. Here in Finland this is usually done by sulfur removal plants functioning with wet method. In sulfur removal plants, a mixture of sea water and limestone is sprayed against the flue gases, and the sulfur dioxide in the flue gases forms gypsum together with the limestone. The process is conveyed in an absorption tower, in which the action occurs in a closed cycle. Because of this, both the chlorides in the sea water and the sulfur created in the process cause a strong corrosion effect. In addition, there is strong wear effect because of the finely grated limestone, both in the recycling tubes and in the absorption tower itself. Both corrosion and wear protection can be achieved efficiently with rubber lining. Ion exchangers for water treatment plants There are high quality standards for the water to be used when making superheated steam. The desired qualities for the water can be achieved in a separate water treatment plant. The ion exchangers, in which the ion exchanging mass is stimulated in a pressure container according to a specific program with either acid or alkali, have at their best a structure lined with rubber. When using vulcanization as protective coating, a maintenance free working time of over 30 years can be achieved, according to experience from the field. Materials: Butyl rubber (BIIR) halogenated with bromine Materials: Vulcanites made of natural rubber or styrene butadiene rubber 7

8 Marine technology Ship building In ship building, both the sea water pipes and their filters are subject to both mechanical wear and corrosion. Rubber varieties which are soft and mostly based on natural rubber have proven to be functional solutions. There are legislative restrictions also against emissions of the ships. When it comes to flue gases, the concentration of sulfur dioxide is lowered with flue gas washers, in which structures with rubber lining protect the system from corrosion. In these targets, the experiences that have been gained from coal power plants are utilized. Materials: NR, BIIR, chloroprene 8

9 An apparatus functioning in a marine environment utilizes the qualities of rubber either as material preventing corrosion or as technical construction material. Offshore industry In addition to corrosion and wear, also the mechanical strain against the structures can be suppressed by using rubber materials as flexible elements. In oil production rafts that float in the sea, the strain caused by the waves to the pipes rising from the sea floor is suppressed onto the surface of the pipes with flexible vulcanized layers. In these cases, particularly strict technical requirements are applied to the rubber varieties in use. Materials: Chloroprene, CSM 9

10 Chemical industry 10

11 The usage of rubber lining has originally sprung from the needs of chemical industry. Strong acids and alkalis and their concentrates present a real problem to the processing machinery.. High temperatures and negative pressure as well as chemistry set forth challenges to the methods with which the effects destroying structural materials can be eliminated. When it comes to rubber lining methods, a wide base of elastomers and a reliable fixing method make it possible to solve the problems with coating. Under techno-economic scrutiny, a steel structure with rubber lining is most competitive in the kinds of targets where the proportions of the structures are considerable, such as large containers and tanks. can also be used to protect concrete structures. Materials: Several different possibilities depending on the process. 11

12 Metal industry 12

13 There are phases in manufacturing various metals in which for example the surface of steel is chemically treated. Tanks and storage containers containing the liquid circulating in them are typically equipped with a rubber lining suitable for the process. The structures used in industry can be protected against corrosion and wear with rubber or other elastomers. is an economical way to create products that must function under difficult conditions virtually maintenance free as well as long-lived. Materials: Vulcanite, BIIR, CR, CSM 13

14 Mining industry Coatings attached by vulcanization are being used in mining industry mostly in the ore beneficiation phase. In flotation, flotation elements and mixing bodies in these elements are typical structures where rubber lining is used. Tailings that are created as a side product are typically transported to a landfill with steel pipes lined with rubber. The chemical beneficiation process in which the wanted metals are dissolved from the ore is an extremely difficult challenge to the process equipment in the sense of a corrosion problem. is used to prevent mechanical wear of the structures that occurs simultaneously. Chemicals, high temperature and mechanical wear and tear strongly direct the choice of the rubber type. Also the methods of attachment must be chosen according to the environment. Materials: BIIR and its various versions, CSM. Talvivaara 14

15 Rubber as a coating for steel structures protects them either against mechanical wear or corrosion. 24h care: provides service and checks for the rubber parts subject to wear, thus ensuring the continuity of the process at the Yara Siilinjärvi factory. 15

16 qualities Normative chemical durability Acids Acetic acid Hydrofluoric acid Phosphoric acid Chromic acid 50 % Formic acid Sulphurous acid Sulphuric acid 30 % Sulphuric acid 50 % Sulphuric acid 80 % Sulphuric acid 90 % Hydrochloric acid Nitric acid 5 % Nitric acid 20 % Nitric acid 40 % Hydrogen peroxide 30 % Alkalis and solutions of salts Ammonium hydroxide Bisulfites Phosphates Hypochlorites Potassium hydroxide Carbonates Chlorides Brine Sodium hydroxide Soap solution 1 % Sulfates Nobonit Novenit Nokim Cr CSM/PVC BIIR Gases Chlorine Chlorine water Chlorine dioxide Sulfur dioxide Organic compounds Alcohols Acetone Petrol (gasoline) Benzene Ethyl acetate Phenol Chlorinated hydrocarbons Methyl ethyl ketone Mineral oils Turpentine Nobonit Novenit Nokim Cr CSM/PVC BIIR Resistant in normal use, minor effect at most Fairly resistant, minor effect possible Resistant in appropriate conditions, otherwise considerable effect Not recommended The relative effect on various rubber qualities at room temperature are shown in the table. When the temperature increases, the effect of the chemicals increases, and the increase is dependent on both the polymer and the chemical. 16

17 Typical physical attributes Anticorrosion coatings Polymer Specific gravity Hardness Tensile strength Elongation at break Adhesion to steel Control voltage Operating temperature Nobonit NR 1,06 70±5 ShD > 40 MPa > 5 % > 6 MPa 5 kv/mm < 100 C Novenit NR 1,26 70±5 ShD > 40 MPa > 2 % > 6 MPa 5 kv/mm < 85 C Nokim NR 0,96 40±5 ShA > 10 MPa > 700 % > 6 N/mm 5 kv/mm < 70 C BIIR BIIR 1,27 50±5 ShA > 5 MPa > 370 % > 4 N/mm 4 kv/mm < 100 C CR CR 1,44 55±5 ShA > 10 MPa > 360 % > 4 N/mm 2,5 kv/mm < 85 C CSM/PVC CSM/PVC 1,44 70±5 ShA > 8 MPa > 300 % > 4 N/mm 5 kv/mm < 80 C Anti-wear coatings Polymer Specific gravity Hardness Tensile strength Elongation at break Tear strength Control voltage Operating temperature S NR/BR 1,10 60 ShA > 20 MPa > 500 % > 50 N/mm < 90 mm 3 / 10 N < 70 C S NR/BR 1,03 40 ShA > 8 MPa > 400 % > 25 N/mm < 60 mm 3 / 5 N < 70 C 17

18 Structures that can be lined with rubber, and the working methods associated with it, place particular demands on the structure of the object to be lined. Steel, cast iron and acid-proof steel can be lined with rubber. In some cases concrete surfaces can be lined, too. The object must be structured so that access to every surface to be lined is easy by and by hand tools. An appropriate structure will facilitate lining and ensure a good result. To secure a good rubber lining, the following factors should be taken into account concerning the structure of the object: No air pockets must be left inside the metal structures. If air pockets cannot be avoided, exit apertures must be drilled for the air on the opposite side of the lining. Sharp corners and edges must be avoided, and corners are to be rounded to radius of 4 mm. Badly corroded metal parts cannot be lined. The thickness of rubber on the metal should be taken into account when the pipes and pumps are being designed. Piping of diameter mm should be made of seamless pipe. Larger sizes may be welded. Long or bended pipes should be divided into sections to facilitate lining. The surface to be lined should be smooth and impermeable, without pores from casting or welding. The structure must be welded from the side that will be lined. The welding seams have to be solid, tight and polished. Riveted structures and spot welding must be avoided. The structure to be lined must have walls so thick, or so reinforced with struts, that it does not deform during lining, transportation or utilization. 18

19 Measurements of pipes to be lined with rubber Measurements of straight pipes, bends and T-pieces to be lined. Nominal size mm Straight pipes A max mm 90º curves B max mm T-pieces C max mm T-pieces F max mm T-pieces E max mm Complicated pipe constructions must be divided by collar attachments into standard parts to facilitate rubber lining. In cases that are unclear, please send the drawings to us, so we can give more detailed instructions. 19

20 Established in 1989, Yhtiöt Oy is the leading polymer technology group in the Nordic countries. Group includes Oy s factories in Vammala and Kiikka, Sekoitukset in Kerava, and factories in China and Russia. The business group has about 400 employees, and its turnover in 2012 was approximately EUR 55 million. The product range includes hoses, plastic and moulded products, rubber coatings and linings, polyurethane and fluid silicone products, as well as rubber compounds, sheets and mats. In-house mould design, mixture development, and product and method design ensure that our products meet customer requirements and facilitate development in the future as well. Our customers are international technology companies, and a significant proportion of our product solutions are targeted at international markets. Vammala plant Moulded and plastic products Industrial hoses Polyurethane products Vibration dampening mats Wear elements s Rollers Mill linings Kiikka plant jips.fi 2014/03 Oy P.O. Box 13 FI Sastamala, FINLAND Tel