Engineered Temperature. Solutions for chemical and petrochemical refineries

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1 Engineered Temperature Solutions for chemical and petrochemical refineries

2 Temperature at Endress+Hauser The Endress+Hauser Group of companies Endress+Hauser is a global supplier of products and solutions for the process industries. Innovative technologies that lead to an excellent price/performance ratio of our products and services support the competition ability of our customers in quality, reliability and efficiency. With a finely tuned network of production, sales companies and representatives Endress+Hauser has a strong presence on all world markets. Endress+Hauser stands for continuity, branch specific know-how and for long-term customer relationships. Areas of activities: The production locations in Nesselwang (Germany) and Pessano near at Milan (Italy) are the competence centers for temperature measurement technology within the Endress+Hauser group. Here transmitters, measurement inserts, thermowells and thermometers as well as bespoke solutions are produced. Accredited calibration laboratories (DKD, SIT) are available in both sites. Endress+Hauser Wetzer Endress+Hauser Sicestherm

3 Temperature measurement in the petrochemical industry It is impossible to imagine our daily lives without mineral oils. It is a long process from crude oil to the end product: From exploration to production until final processing in refineries, petrochemical and chemical plants. Temperature measurement technology is particularly demanding for the different methods of petrochemical and chemical processes. Thermometers for process furnaces, desulfurization reactors or Claus-furnaces require a high degree of experience and know-how in order to be able to design the sensors for a safe and reliable measurement in accordance with the requirements. In addition to the high-quality standard thermometers Endress+Hauser also offers custom-made solutions for surface temperature measurement as well as individually designed multi-point measurement systems in reactors. Innovative developments to increase safety, optimize flexibility and thereby increasing process availability offer real additional benefits. A complete portfolio of transmitters with the most modern fieldbus technology rounds off the product basket. Contents Page Temperature at Endress+Hauser Project management Temperature measurement in process furnaces Temperature measurement in reactors Process connection with safety chamber System integration Advantages of fieldbus systems Certification and tests

4 Project management Coordinated project management in the different process areas and industries is becoming increasingly important. To do justice to these requirements, Endress+Hauser has analyzed and optimized the internal processes for project management in detail over the last few years. Projects with custom-designed solutions for temperature measurement require a higher degree of coordination between customer and supplier in comparison to projects with standard products. For this reason numerous project teams are at the customer s disposal worldwide. Engineering and services in plant life cycle Project Management In order to achieve maximum efficiency, an interdisciplinary team is formed at the beginning of a project. The project manager guarantees a smooth course during the complete engineering process. Engineering (Basic Engineering) The feasibility of the project is checked within the framework of the Basic Engineering and the schedule is coordinated with the customer. Detailed Engineering, however, includes material selection, drawing preparation and the selection of suitable system components for connection to primary systems. Engineering (Detail Engineering) Nowadays computer supported planning tools make mechanical simulation possible and support the optimization of the plant in the engineering phase. Endress+Hauser supports this planning with CAD data for every device and thereby contributes considerably to the reduction of planning time. The electronic data are provided in 2 D or 3D models on request. Production Modern machine workshops, accredited welding methods and trained specialist staff guarantee the high quality in production. The production facility is ISO9000 certified.

5 Quality checks Besides fixed and standardized quality controls Endress+Hauser offers additional examinations and certificates especially for use in the area of the refineries and petrochemical plants. Factory acceptance test Inspection can take place both directly at the production site or in one of our logistics centers. The project manager carries out the inspection of the produced order together with the customer and documents the results in the acceptance report. Delivery Despatch Custom-designed solutions require special procedures with respect to packing and transportation. By using especially designed packaging, careful loading and transportation by approved logistics partners makes sure that the measurement systems arrive both punctually and securely. Site acceptance test Optionally Endress+Hauser offers the possibility of a site acceptance test. Installation supervision Fault free installation is decisive for the quality and longevity of the measurement system. Endress+Hauser supports the project during its complete installation worldwide with an experienced supervisor. Plant life cycle management With W@M (Web based Asset Management) Endress+Hauser offers an open and flexible information platform. This supports you along your business processes and the complete life cycle of your equipment. With this all the necessary information regarding safe installation, commissioning and maintenance of the devices is at your displosal. 5

6 Temperature measurement in process furnaces If the surface temperature of a reactor wall or a pipe needs to be measured, then in most cases the sensors, depending on the application, are attached by soldering, welding, screwing-on or clamping. Since, in this case, the thermometer is not in contact with the medium, the demand made of the themometer is low. This is different when measuring the temperature pipe surfaces in process furnaces. Here the demand made of the thermometer is extremely high. Process furnaces are indispensable modules in the various production processes refi neries, petrochemical and chemical plants since the medium to be processed must be heated before it is transferred to a distillation column or a reactor (see example atmospheric distillation). Here the liquid medium is pumped though a pipe bundle which is installed in a furnace fi tted with burners. The measurement serves mainly to guarantee the process effi ciency and to monitor for deposits within the pipes. Application: Atmospheric distillation The distillation serves to separate crude oil into its natural components. It is pumped out from storage tanks through a separator into a pipe furnace where it is heated up to approximately 350 to 400 C. As a steam liquid mixture it reaches the fi rst distillation tower at atmospheric pressure. Furnace chamber Heat exchanger Skin point temperature measurement Tube-Skin- Thermometer High temperatures, existence of aggressive burning gasses and expansion of the heat exchanger pipe bundles make heaviest demands on the tube-skin thermometers used in relation to: Material selection. Thermometer design. Connection of the thermometer to the pipe. 6

7 Material The choice of material has a decisive effect on the thermometer life span and therefore the reliability of the temperature measurement. Among other things the suitable material is determined by the furnace temperature and the fuel used. By this, the effects due to radiation and open flames should be minimized. The use of Hastelloy X (2.4665) has particularly proven itself in process furnaces. Versions in AISI 316 L ( or ), AISI 321 (1.4541), AISI 347 (1.4550), Inconel and others materials are also possible. Design In the thermometer design the movements of the heat exchanger pipes and the optimal positioning are taken into account in the furnace. The pipe expansion is compensated for by expansion coils. Outer wall Pipe Neck (Nipples) Expansion coils Fixingclamp Welded pad Version with expansion coils: Available as flexible sheathed material or in a more robust execution with prepared expansion coils fitted to the furnace geometry. Connection to the pipe The connection of the thermometer tip to the pipe surface has a decisive influence on the measurement precision. The measurement result can be significantly influenced by corrosion, in combination with open flames and/or radiation. The handling during installation and removal must both be taken into consideration. Pad Thermocouple Sheath The thermocouple is fixed by formed brackets welded onto the pipe surface; if necessary the tip is pushed into a contact block welded onto the pipe. Thermocouple with pad for welding to the pipe surface. Thermocouple with a knife edge (wedge formation) for welding to the pipe surface. In addition there are a number of futher bespoke solutions available for special requirements. 7

8 Temperature measurement in reactors Measurement of a temperature profile in a catalytic reactor process Catalytic reaction processes are required if the reaction can only take place with a sufficiently high speed in the presence of a catalyst. These include ammonia synthesis, methanol synthesis, but also gasoline or fuel oil desulfurization. In these methods the reaction of the catalyst rests while it is being it is being mixed with gas or liquid. The particles on which heterogeneous catalysts are fixated are packed so tightly that a solid bed is generated. This is why they are generally known as flat bed reactors. At an uneven distribution of the reactors via the catalyst it can sometimes come to a so-called channeling of the catalyst bed. This then leads to an inefficient use of the catalyst and the generation of local high temperature points known as Hot spots. The danger here is that the catalyst is deactivated or damaged as of a certain hot spot temperature. The recording of temperature values in the different catalyst layers is therefore indispensable for the operator. On the one hand the uneven speed, concentration and temperature profiles have a negative effect on the process cycle and therefore on the product quality. On the other hand this also has an effect on the life- and the maintenance cycle of the reactor and is therefore a significant factor in lowering the operating costs. In the following multi-point thermometer systems from Endress+Hauser are introduced, which fulfill the mentioned requirements and are suitable for the different forms of flat bed reactors: Multipoints for pipe bundle reactors - the catalyst is in thin parallel fixed pipes (diameter cm). Multipoints for flat bed reactors with continuous catalyst reaction. Multipoints for flat bed reactors with catalyst beds. The Endress+Hauser measurement solutions are individually designed under the requirement of maximum safety.

9 Pipe bundle reactors Pipe bundle reactors serve the synthesis or further processing of chemical raw materials. The heart of the reactor coat is a pipe bundle which is rinsed by a heat exchanger (boiling liquids, pressure water, salt melts). Every single pipe in the bundle is filled with catalyst material and therefore represents a reactor in which hot spots can appear. One thermometer with the smallest possible diameter and as many test points as possible on its total length must be placed within these pipes. For these requirements multi-point thermocouples are used. There are basically two versions: Version 1: Multi-point thermometer with common sheathing. Embedded centrally in highly purified magnesium oxide powder within a metallic sheath lies the common cable (positive thermo-leg). The negative thermo-legs are placed around this. This construction makes it possible to produce test points by connecting the thermo-legs at different positions throughout the complete length of the thermometer. Construction: OMP Sensor (optimized multipoint) Middle positive thermocouple leg Negative thermocouple leg Stainless steel sheath Wall Hot Junction Thermocouple leg connection Version 2: Multi-point element with individual sheaths Several mineral insulated thermocouples and protected by a metallic sheath are exactly placed into a metal tube. The generated multiple sensor is then drawn in several steps up to the required diameter. Due to the larger thermo-wire diameter the OMP construction considerably more robustly, the second version makes a larger number of measurement points possible with the same outside diameter. Both versions stand out due to the following advantages: Large number of measurement points with simultaneously small sheath diameter (Ø from 3 mm, dependent on construction and number of measurement points). Can be delivered in lengths up to more than mm. High measurement accuracy and long term stability of the measurement points due to insulation with highly purified MgO powder. Large selection of available materials (e.g. SS316, SS304, Inconel 600). Thanks to the malleable sheath material very long thermocouples can be economically transported and stored in coiled up form. Variable process connections by attaching

10 Temperature measurement in reactors Rigid multi-point thermometers Frequently rigid, straight multi-point thermometers and thermowells are used for measuring temperature profi les in fl at bed reactors. Such a thermometer consists of a thermowell with process connection, a number of sensors (mostly thermocouples) and a terminal connection box. In addition, a construction is possible with individual interchangeable measurement elements. To reach high reaction speeds, the individual measurement points are in contact with the thermowell, thus conducting the process temperature. The terminals or transmitters can be fi tted in the connection box which is either fi tted directly onto the assembly or mounted remotely. Connection box (EEx d version) with transmitters for multiple measurements. Gas tight couplings for interchangeable thermocouples. Multipoint thermometer with three measurement points. Fast reaction time dus to sensor contact with the thermowell. Octoplus systems offer the possibility to distribute measurement point three dimensionally in the reactor. Flexible pipes are brought into the reactor via a common process connection. The thermocouples are distributed within the reactor according to the specifi cation in order to achieve the desired positions of the measurement points. An additional advantage of a spcially engineered Octoplus system safeguards the exchange of single thermocouples during the down time or during regular process times. The fl exibility allows operation and maintenance costs to be lowered considerably. Both systems are individually designed for the measurement task. Process conditions such as pressure, temperature and the type of medium are decisive for the choice of material and design. Since most reactors have a construction especially tailored to the process, every multi-point system is individually optimized for the application. Reactor specifi cations such as accessibility, fi lling and emptying as well as the product fl ow are taken into account when designing the system. 10

11 Process connection with safety chamber To do justice to the high safety requirements in reactors of petrochemical plants, Endress+Hauser offers a special process connection with safety chamber. This safety chamber represents a second process barrier and is available both with straight multi-point thermometers and Octoplus systems. Leaks in the thermowell or in the sheaths are contained by the safety chamber, the process medium cannot reach the outside environment. Pressure gauges monitor the pressure in the safety chamber and transmit an alarm if a leakage is detected. Optionally the safety chambers can be fi tted with welded together or interchangeable thermocouples. The interchangeable version offers full fl exibility for service and maintenance into combination with a maximum safety. Safety chamber with welded thermocouples (not interchangeable). Positioning outside the reactor. Safety chamber; thermocouples are fed through compression fi ttings and can be interchanged during down time. 11

12 System integration Process availability, reliability and plant safety are the center of the requirements in the petrochemical processes. Additional information regarding the measurement point and supplementary diagnoses of modern temperature transmitters substantially contribute to this. The diagnostics contain standardized functions which monitor and report e.g. an open circuit or a wiring fault. Corrosion at the terminals as well as the sensor cables is also supervised and recognized early. Maximum safety is offered by the backup function which automatically switches over the sensor on the channel operation with a redundant temperature measurement on failure or malfunction. The large number of Ex-approvals regarding pressure tight capsulation and/or intrinsic safety document the extensive application possibilities in Ex hazardous areas. HART devices which have been designed to the IEC61508 regulations, today set the standards for safety and reliability in self toring electronics and innovative circuit moni- concepts. System integration by means of transmitters can be done via 4 20mA signals or with the help of fi eldbus systems. Endress+Hauser offer a complete portfolio of temperature transmitters using the most up-to-date technology which can be used in all types of applications. Field housing TMT142 TMT162 TMT162 TMT162 TMT125 DIN Rail TMT122/112 TMT125 Head transmitter TMT182 TMT TMT TMT85 1-channel universal 2-channel universal 2-channel universal 2-channel universal 8-channel universal 12

13 Advantages of Fieldbus systems In cooperation with universities and research institutes Endress+Hauser consequently advances the further development of the communication technology. Through this the temperature transmitters are available for the most important fi eldbus protocols such as FOUNDATION Fieldbus, PROFIBUS and HART according to the latest standards of process automation. Fieldbus standards, integration and system tests are checked and guaranteed by certifi ed fi eldbus laboratories. The decision on the right system choice primarily depends on the use of the temperature values. Essentially the choice is to distinguish between three different ways of application: - Purely monitoring the measured values. - Use the measured value for control purposes. - Use the measured values for safety purposes. Monitoring the measured values This application case makes the least demands on speed and availability. Therefore it is recommendable at the pure monitoring applications to minimize the costs of system integration. For this decentralized transmitters which are networked to the system using a modern fi eldbus systems is to be recommended. Fieldbuses save considerable wiring costs and increase the transparency by additional information. Using the measured values for control purposes For compliance with process limits and safeguarding the process quality measurements are necessary for control purposes. This application can also be covered today with modern fi eldbus systems. Both the cycle time of a fi eldbus system and the availability completely fulfi ll the requirements for the temperature control. Using the measured values for safety purposes Frequently multi-points are put into reactors for the supervision of hot spots. In such cases reliability and availability are the most important criteria for system integration. The lowest risk in such cases represents the classic period to point connection... TMT125 Besides the single channel fi eldbus transmitter Multi channel temperature transmitters with a FOUNDATION Fieldbus protocol can be offered in multi-point measurement applications. These offer a very economical alternative with all the qualities of the single channel version but with up to eight inputs. Endress+Hauser takes on the projecting of the required components from the measurement point up to the control cabinet. 13

14 Certification and tests Demanding processes in refineries and petrochemical plants require a maximum amount of quality. Since temperature measurement plays such a decisive role for the safety of the plants the individual components of the temperature measurement point are subject to careful examination at Endress+Hauser in their own test centers. The quality of the materials, processing and the important qualities of the thermometer systems are proved by testimonials and certificates and can be traced backwards for years. Deviations from the specified qualities of the component can be faults in the form of material problems or separations. These are for example cracks, pores, cavities or composition faults. The methods of nondestructive test are suitable for the proof of such problems. Here the use qualities of the component are not affected. Inspection certificate The inspection certificate EN for medium contact parts is produced by a department independent of the production and confirmed by an expert independent of the production of the manufacturer ( works expert ). The material tests carried out and the additional quality controls agreed on are certified with detail of the test results and under supervision of an independent authority. NACE The NACE MR0175 standard is essentially a listing of materials that are considered suitable for use in surroundings containing sulfur hydrogen (sour gas). New suitable materials are included in this standard after passing through an extensive approval process (annual update). PMI (Positive Material Identification) This nondestructive material identification as well as check of welding connections are frequently used at acceptance tests. Assessment according to the pressure equipment directives. If the multi-point thermometer is equipped with a safety chamber (as described on page 11), this chamber represents a pressure containment equipment. This is because in the case of a fault condition (e.g. thermowell rupture) this piece of equipment is filled with process pressure. Depending on the type of fluid, the volume of the chamber and the process pressure the corresponding conformity assessment module is consulted and used. X-ray testing (non destructive test) Faults like inclusions, pores, tears etc. in the base material and/or in the welded seam are seen. Furthermore the exact positioning of the welded components can be checked. 14

15 Dye penetration test Red-white-method Suitable for checking material surfaces and welded seam surfaces. So for example cracks can be detected. It is applicable for the welding seams of stainless steels, austenitic materials and metal based alloys. Hydrostatic pressure test internal/external Using the internal and external pressure test the strength and pressure tightness of thermowells and process connections can be checked. Helium leakage test Pressure tightness test for thermowells, welded seams, screwed fittings. Depending on the thermometer design and thermometer size it can be pressurized internally or externally with helium gas. Calibration Our own accredited laboratories for the calibration of resistance sensors and thermocouples to ISO/IEC 17025, DKD and SIT guidelines are available for internationally recognized calibration certificates. 15

16 Further documentation Temperature measurement Thermometers and transmitters for the process industry. Brochure: FA006T09 E+H= C - the law of temperature Temperature measurement in dialog. Grafi cal Confi gurator. DVD: CD016R09 Competence in temperatur for your success. Brochure: CP002R09 Competence in Oil & Gas Full range of solutions to increase safety and production effi ciency. Brochure: SO502B27 Calibration of thermometers Basics, requirements and standards for industrial thermometers. Brochure: CP004R09 Instruments International 12.06/I.I. Endress+Hauser Instruments International AG Kaegenstrasse 4153 Reinach Switzerland Tel Fax info@ii.endress.com CP003R/09/en/ KKW/INDD CS2