Furnace Modification Research Articles

Technology for Optimizing Flue Gas Pollutant Emission Reduction in Oil Field Heating Furnace Combustion

The energy consumption of the heating furnace is an important part of the energy consumption of the oilfield gathering and transportation system. The low energy efficiency of the heating furnace will directly lead to the increase of oilfield production costs. In response to the national energy-saving and emission-reduction policy, the oilfield has implemented energy-saving practices in heating furnace load adjustment, efficient combustion, excess air coefficient control, flue gas waste heat utilization, and furnace modification. It is clear that the energy efficiency of oilfield heating furnaces is still lower than foreign advanced levels. There is an urgent need for further energy conservation and efficiency enhancement. MVR low-temperature flue gas heat recovery technology, flame shape matching technology, nanofluid heat transfer enhancement technology, solar auxiliary heating technology and other new technologies that can be used for energy saving and consumption reduction of oilfield heating furnaces provide a reference for oilfield heating furnaces to tap the potential and increase efficiency.

Experiences in Improving Efficiency of Energy and Other Resources in Metal Industries in Nepal

The construction sector uses various metals like steel (for frames, reinforced concrete), iron (wrought iron for beams, trusses, girders), aluminium (ceiling and walls, window frames, HVAC systems etc.) and copper (cladding, electrical wiring, oil & gas lines). Due to increasing pressure on various resources like energy, chemicals and raw materials, economic edge can be sustained only through high resource efficiency. Adopting resource efficient cleaner production (RECP) measures will improve economic and environmental performance, including reducing greenhouse gas emissions; in turn, this will make them less vulnerable to changes in external conditions and more competitive. With co-funding from the EU SWITCH-Asia Programme, the project METABUILD (www.metabuild-southasia.org) aims at implementing sustainable production processes and practices in 400 SMEs across Bangladesh, Nepal and Sri Lanka besides creating a conducive environment for further adoption of sustainable production processes in the metal products supply chain for the building and construction sector. In Nepal, the project has already engaged with 82 metal industries. These cover different sectors such as fabrication, wire drawing, electrical cables, re-rolling, galvanizing/electroplating, casting etc. and are in multiple locations viz. Kathmandu, Lalitpur, Morang, Sunsari, Rupandehi, Bara, Parsa, Kaski districts. RECP measures such as use of daylight, replacement of inefficient lights by LED lights, power factor improvement, furnace modification, waste heat recovery, insulation etc. have been implemented. These have led to savings in energy and raw materials, at the same time reducing generation of wastes from these participating industries and improvement of occupational health and safety (OHS). This paper will explain the mode of engagement with industries, details of the resource efficiency measures implemented and estimated saving.

The Utilization of Rice Husk with Furnace Modification Based on the Heat Exchanger Pipe Type for Sustainable Energy of Traditional Drying

The Utilization of Rice Husk with Furnace Modification Based on the Heat Exchanger Pipe Type for Sustainable Energy of Traditional Drying

PERBAIKAN TEKNOLOGI PENGOLAHAN, MODIFIKASI BENTUK DAN UKURAN, SERTA PENGEMBANGAN PRODUK ALTERNATIF GULA AREN

This project aims to provide knowledge, skills and facilitate the producers in improving the product quality and marketing through the improvement of product. This project was conducted by establishing demo plots to selected palm sugar producers. The activities include providing extension, workshops on processing, packaging technologies for palm sugar, entrepreneurship vision, business management, and strategic for marketing. This project successfully introduced the suitable technologies to produce more hygienic palm sugar with more interesting shape, more uniform in size, more long-lasting shelf-life compared to previous technologies applied by the producers. In addition, the introduction of plastic pipe made the palm sugar sap is much more sterilized and cleaner than the bamboo-based technology and furnace modification can improve processing 48 minutes faster than before and save energy up to 23 %. Although the introduced technology to process the palm sugar did not change the nutrients content, the product quality met the SNI standards. The introduced techniques also prolong the shelf life from 24 days to 126 days. There was not any difference in terms of selling prices to both products. However, the price of alternative product (powdery brown sugar) was almost 4 times higher than the traditional products (block palm sugar). K eywords : Processing, size, shape, packaging, quality, and marketing

Mathematical Modeling of the High Temperature Treatment of Birch in a Prototype Furnace

In recent years, various wood modification technologies have been commercialized as alternatives to the traditional chemical treatments for wood preservation. The high temperature heat treatment of wood is one of these commercially viable and environmentally friendly alternative wood modification technologies. During this treatment, wood is heated to temperatures above 200°C by contacting it with hot gas. The chemical structure of wood changes leading to increased dimensional stability and resistance to microorganisms. Wood darkens making it aesthetically more attractive. However, it loses some of its elasticity. Therefore, the high temperature heat treatment has to be optimized for each species and each technology. The mathematical modeling is an important tool for optimization. It can also be used as a powerful tool for furnace modification and design. A reliable and predictive model was developed to simulate numerically the heat treatment process. Heat treatment experiments were carried out in the prototype furnace of the University of Quebec at Chicoutimi. The model was validated by comparing the predictions with the experimental data. In this paper, the results of the model applied to birch heat treatment are presented. The model predictions are in good agreement with the data.

Applying process design software for capacity increase and revamp of distillation units

The paper presents the results of feasibility study for increase of crude processing capacity and improves of energy efficiency of crude oil distillation units. Results introduce that boosting up the distillation capacity was solved while keeping the flexibility of units for processing different type crude oils. Analysis of heat exchanger network resulted significant reduction in fuel consumption and in CO2 emission (93 × 106 GJ year−1 and 3,030 tCO2 year−1, respectively). Modification of furnace of one of the distillation units showed 63 GJ kt crude −1 saving in energy and 4.5 tCO2 kt crude −1 decrease in emission.

Effects of CZSi furnace modification on density of grown-in defects

During large diameter Czochralski silicon growth, heat zone and argon flow influence the formation of defects in silicon crystal by changing the distribution of temperature. Different silicon crystals with various density of grown-in defects were grown by replacing the popular heater with the composite heater and changing the popular argon flow into a controlled flow. The experimental results have been explained well by the numeric simulation of argon flow.

The development, verification, and application of a steady-state thermal model for the pusher-type reheat furnace

This article outlines the development of a steady-state thermal model for the pusher-type steel reheating furnace. Problems commonly encountered with this furnace type are skidmark generation, scale formation, and high energy consumption. The objective of the work is to provide a means by which furnace users might assess the effectiveness of changes to current operating practice, proposed furnace modifications, or new furnace designs in controlling these difficulties. Since a requirement imposed on the model is to operate on current PC hardware, the assumptions and modeling procedures necessary to achieve this goal are discussed. The operation of the model, which develops the thermal history of an individual slab or billet as it passes through the furnace, is presented, and each of the three modules that comprise the model is described. Initial verification of the model has been carried out using data obtained in a separate campaign of plant trials on several 32-m furnace reheating slabs, and model predictions for steel temperatures at six locations within the steel are shown to be in good agreement with the experimental results. The model is used to examine the influence of two skid designs and several placement strategies on skidmark severity and energy losses to the skid system. Although skidmark severity at the intermediate stages of heating is shown to be dependent on both the skid type and the location of any offsets, it is demonstrated that the skidmark present in the discharged steel is determined primarily by the skid type employed over the final section of the furnace. The inclusion of a hearth in the furnace soak zone was found to impose the least severe skidmark on the product, reducing the temperature variation over the bottom face from the level of 130 °C incurred by the best of the soak zone skid configurations examined, to the level of ~85 °C. The results suggest that, in the absence of a hearth section, the use of a well-insulated, cold-rider skid system over the majority of the furnace length, followed by a single offset of all skids occurring at the transition to a short section of hot-rider skids near the furnace discharge, is sufficient to suppress the final skidmark to a level very close to the minimum achievable with that particular skid design. When assessed on the basis of minimizing both the final skidmark and the energy loss to the skid system, this configuration was found to be the best of the skid layouts examined.

Hardening furnace gas savings by retro‐fitting regenerative burners at Metabrasive Ltd

Following an in‐depth study of gas usage at Metabrasive undertaken in 1981, it was decided to treat the reduction of hardening furnace gas consumption as a priority and a paper on hardening furnace gas savings was prepared. A detailed monitoring exercise of the “Wellman” conventionally designed furnace, with a 32 air/gas nozzle mix burner system and brick refractory lining, carried out by independent consultants, showed a net gas consumption of 485 kwh/tonne. The first furnace modification at Metabrasive consisted of the fitting of a recuperative burner system with 8 burners and 4 recuperators, a low density solid hearth and ceramic fibre lined walls and roof. Detailed monitoring by the same consultants showed that a combustion air pre‐heat to 350°C was possible yielding a saving of approximately 25% and a pay‐back period of 2 years. Good even heat distribution and shorter heat‐up and cool‐down times were achieved. The second modification was carried out in 1984, with only slight changes in detail. These were the use of fully proportional air/gas controllers instead of a 3‐step system and high density refractory pads in front of the lower burners to eliminate wear caused by high velocity gases. Problems have been experienced with both these units. The refractory inlet quarts to the recuperators were found to be particularly susceptible to oxide attack. They were made using a metallic fibre reinforced refractory which spalled due to growth of the fibres. Clean air is now ducted from outside the plant which has alleviated the problem. The air valve Honeywell control motors we found to be particularly affected by heat, in spite of being provided for this duty. Sheilding has solved this problem. It was planned to modify the third furnace in 1985 with the same, albeit improved, system. However, combustion technology had moved on rapidly and the regenerative burner systems had reached the proven stage. This method was, therefore, adopted for this furnace.

Graphite Furnace Modification for Second Surface Atomization

Preliminary results from a simple furnace modification are presented. A graphite condensation site has been located inside a commercial graphite furnace atomizer. Solution samples are deposited on the furnace wall and the analyte and other condensible species “distilled” to this site during a high temperature ash. During the atomization cycle, the analyte is revaporized from the “plug” into the higher temperature furnace environment. The plug is radiatively heated and can lag behind the wall temperature by more than 1000 K, thus providing atomization into a higher temperature environment which is more nearly isothermal. The heating program with analyte transfer permits extremely high ash temperatures to be used and offers the possibility of separating the analyte from gaseous, thermal decomposition products from the matrix. Additionally, distortions of the analytical absorbance signal caused by degradation in the pyrolytic surface of the furnace are minimized when atomization from the secondary surface is employed. Limits of detection for Ag, Cr, Cu, Fe, Pb, Sn, and Zn are within a factor of 2 of values determined using wall atomization. Studies are presented on the interference of sulfate on Sn analysis. Improved peak height sensitivity and a decreased dependency on sulfate concentrations have been observed.

Melt growth of Nd : Y 3Al 5O 12 (Nd : YAG) using the heat exchange method (HEM)

Pure and Nd doped Y 3Al 5O 12 (YAG and Nd : YAG) single crystals weighing 2180 g and 7.62 cm in diameter have been grown using the Heat Exchanger Method (HEM). Furnace modifications were necessary to achieve the planar solid-liquid growth interface needed to avoid faceted growth. Crystals doped with 0.6–0.8 at% Nd were free of scattering centers over 90% of their volume while crystals doped with 1.1 at% Nd were only free of scattering centers over 50% of their volume. These scattering centers contained voids and either YAlO 3 or Al 2O 3 depending upon melt composition. Fluorescent lifetime of 3 × 30 mm laser rods fabricated from HEM grown crystals doped with 0.6–0.8 at% Nd was 254 ± 2.5 μsec.