Thermo Tech Engineering (TTE), established in 2006 in Karachi, specializes in energy-efficient solutions such as designing and manufacturing waste heat recovery systems and industrial utilities. The company provides key insights on energy-saving opportunities for steam and thermic oil boilers, crucial for various industrial sectors, while also emphasizing the importance of efficient operation to reduce costs and carbon emissions. TTE offers a range of products and services aimed at enhancing energy efficiency, ultimately benefiting businesses financially and environmentally.

1. Thermo Tech Engineering Making business sense Introducing energy saving opportunities for business

2. TTE Company Profile Thermo Tech Engineering (TTE) was established in 2006 and based in Karachi, Pakistan. Specializes in designing and manufacturing of waste heat recovery systems, industrial utility equipments. We offer complete waste heat recovery system. Custom Design, manufacture, supply equipments and accessories, installation and commissioning. We also offer general fabrication like steel structures, plate forms, machines, tanks etc as well as equipments fabrication of special requirement like yarn process vacuum machine. We have experienced work force and all required equipments, accessories and work facilities. Our workshop is situated in P & T Society Korangi industrial area Karachi.

3. Thermo Tech Engineering Reducing energy use makes perfect business sense it saves money, enhances corporate reputation and helps everyone in the fight against waste energy. Thermo Tech Engineering provides simple, effective advice to help businesses and the simplest way to do this is to use energy more efficiently. This technology overview introduces the main energy saving opportunities for steam hot water and high temperature thermic oil boilers and demonstrates how simple actions save energy, cut costs and increase profit margins.

4. Energy consumption Steam hot water and high temperature thermic oil boilers are commonly used in industrial sectors and in some applications in public and commercial organisations. They are found in circumstances where there is a continual demand for steam hot water or thermic oil in a wide range of industrial processes, such as Textile, Pharma & Food industries. Operation of these boilers is energy intensive and can therefore represent a significant proportion of an organisation’s energy costs. boilers account for some 60% of carbon emissions from industrial operations and buildings. Therefore, it is important for owners and operators of these boilers to ensure that the plant is designed, installed, commissioned and operated with due regard to energy efficiency as well as safety and reliability. This overview covers both steam boilers and thermic oil boilers, ranging in size are available as per client requirement. Steam boilers/thermic oil boiler operate at a higher temperature than hot water boilers. However, the exact operating temperature will depend on the pressure of the system, which varies between individual boilers. The temperature and pressure requirements of a boiler are dictated by process requirements. For information about the hot water boilers, thermic oil boilers, economizers, heat exchangers, then go to TTE website http://tte.com.pk

5. Technology Overview Summary of key areas Being so energy intensive, steam and high temperature boilers offer many energy savings opportunities to businesses and these actions can make significant cost savings. The most appropriate solution will depend on the type of boiler and heating system, the requirements of the process or other heating demands and budget. Opportunities for energy saving in boiler performance These can range from simple maintenance actions to combustion air preheating. Opportunities for energy saving in steam distribution These include checking for and repairing leaks, identifying redundant pipework and ensuring that the system is adequately insulated. Who is this publication for? This technology overview is written for energy managers, project managers and maintenance teams who are involved in the day-to-day operation of industrial steam and HTHW boilers. It provides an introduction to the key issues that users and operators should consider. This publication deals mainly with shell, tubes boilers, as most existing Pakistan boiler plant is of this design, although much of the advice is applicable to other types of boiler. This overview covers some of the straightforward steps to saving from improving operation and maintenance, and upgrading boilers and distribution systems. It also introduces some simple measures regarding distribution systems associated with steam and high temperature boilers.

6. Boilers A boiler is a device that converts the chemical energy of a fuel into a useful heat output, such as steam or hot water. The fuel type most commonly used in Pakistan is gas, but some older coal and oil-fuelled boilers are still in operation. There is also a small number of biomass fired boilers in operation, where there is a good availability of fuel. Inside a boiler, the fuel is combusted by burners. These produce flames, and the hot combustion gases created transfer the heat to water, which has been fed into the boiler from an external source. The feedwater may enter the boiler directly, or via tank. The temperature that this water is heated to will depend on whether the boiler output is steam or hot water. High temperature hot water boilers produce hot water at temperatures of over 90ºC. Hot water boilers producing water at temperatures of 90ºC and below are classed as low temperature hot water boilers and are outside the scope of this technology. There are many different types of boiler design and construction, but all boilers are derivatives of two main types: The shell type, where the hot combustion gases pass down a tube and into subsequent bundles of tubes immersed below water level. The heat from these gases is then transferred to heat the water. Most steam and hot water boilers in the Pakistan are derivatives of the shell type, which are also referred to as ‘fire tube’ The water tube type, where the water is contained in tubes and the hot combustion gases pass around them to heat the water. In either case, the heat must transfer across the surface of the tubes containing the water or combustion gases. Therefore, these tubes are made of materials with good heat-transfer properties. After use, the combustion gases exit the boiler via a chimney known as a flue. The output steam or hot water will be fed out of the boiler into a distribution system. This is a network of insulated pipes that transfer the steam/hot water to the point(s) at which it is used.

7. Scope for boiler savings Depending on the existing boiler, savings of 20% or greater are possible. The following table gives indicative savings for a range of energy saving measures. Technique/method Energy saving potential Operation and maintenance of boilers Up to 5% Boiler and burner management systems, digital combustion controls and oxygen trim Up to 5% Economisers Up to 5% Blow down heat recovery Up to 4% Combustion air preheating Up to 2% Water treatment and boiler water conditioning Up to 2% Total dissolved solids (TDS) control and boiler blow down Up to 2% Flue-gas shut-off dampers Up to 1% *Note that the percentages above represent potential saving if only the corresponding action is taken. Implementing several at once will not always result in savings that are a simple addition of figures.

8. Medium-cost savings There are a number of energy saving measures that require some financial outlay. These include: Recovering flue-gas heat Installing flue-gas dampers Installing variable speed drives for combustion air fans Minimising radiation heat losses Checking that water treatment is adequate Optimising boiler blowdown Recovering blowdown heat Reheating combustion air. Flue-gas heat recovery Boiler flue gas contains a great deal of heat that can be recovered and used elsewhere. Flue gas from a boiler is at a higher temperature than that of the steam produced and is typically around 200ºC in most modern TTE steam boilers. The potential for heat recovery is often limited when the combustion gases contain acidic elements, such as with coal or oil firing. In these cases, it is usually necessary to maintain the exhaust-gas temperature above a certain level to prevent the condensation of acid. Still, heat recovery is a viable option for most businesses using gas-fired boilers. The most common action is the installation of economisers. Economisers A tried-and-tested technology for recovering heat from flue gases for shell and water-tube boilers, an economiser is a gas to-water heat exchanger located within a purpose-built flue section. The main use of the heat from economisers is to preheat boiler feedwater before it is introduced into the boiler. The relatively cool feedwater is pumped through the heat-exchanger tubes where it absorbs heat from the hot flue gas exhausted from the boiler before being pumped into the boiler. Therefore, during normal boiler operation, the economiser receives a continuous flow of water. Condensing economisers use the same principle, but further reduce the flue-gas temperature, which improves the boiler system efficiency further. Simpler economisers are also available that consist of a water-jacket fitted around the stack, but these are less efficient.

9. Install flue-gas dampers During stand-by, there is a continuous flow of heated air through the boiler to the flue due to natural convection resulting from heat transfer from the water and equipment. This heat is lost from the boiler to the chimney and can be significant where boilers are put on stand-by regularly due to process load changes. The function of a shut-off damper is to restrict airflow through the flue and prevent heat loss from the boiler when on stand-by. Dampers are particularly suited to situations where intermittent capacity is needed, and where it is necessary to operate a boiler in stand-by mode and cycle it to keep the required pressure/temperature conditions. Automatic, gas-tight, shut-off dampers are widely available for installation in boiler flues. A cheaper alternative for forced-draught burners is to install an automatic, air-sealing damper at the combustion-air fan inlet. This is particularly economic for retrofit projects. An automatic, fully closing damper, fitted either at the flue-gas exit or at the burner combustion-air fan inlet, closes after any post-combustion purge operation. This reduces the ingress of cold air and prevents air being drawn through the boiler when it is not firing. Therefore, this reduces the system standing losses and prevents excessive fuel being consumed. (overleaf) shows a typical shut-off damper installation. Damper installation The installation of dampers is relatively simple and may be undertaken by the TTE. The work involves cutting the flue ducting (if a hot-gas damper is chosen), inserting the unit, complete with servomotor drive, and making the necessary electrical interlock connections. Safety interlocks are fitted to prevent the burner firing with the damper closed, which avoids the potential build-up of unburnt gas in the boiler or a build-up of carbon monoxide in the boiler room. Electrical connections are then made from the damper to the appropriate control circuit in the burner panel. The installation cost is relatively low compared with the savings obtained. This device is ideal for stand-by boilers and those with cyclic loads. Air-inlet sealing dampers are also a cost-effective option; these are generally smaller and are not exposed to hot and, occasionally, dirty flue gases.

10. Preheat combustion air The air required to combust the fuel is generally taken from within the boiler room, either assisted by a fan in a forceddraught burner or unassisted in the case of a natural-draught burner. This incoming combustion air is at boiler room temperature, which is cooler than boiler operating temperature. Therefore, boiler efficiency can be improved by preheating the incoming combustion air up to boiler operating temperature. This reduces the mount of boiler energy that becomes transferred to the combustion air as it enters the system, and, as a result, provides a higher flame temperature from the burner. The usual heat sources for heating combustion air are: Heat remaining in the flue gases Higher temperature air drawn from the top of the boilerhouse Heat recovered by drawing over or through the boiler casing to reduce shell losses. Using the heat remaining in the flue gases can be expensive and requires a stainless-steel, plate-type heat exchanger to be fitted in the boiler-flue system. It is also necessary to fit bypass dampers when firing fuel oil instead of natural gas. In addition, the forced-draught fans must be capable of overcoming the additional back pressure. Most gas and oil burners used on boiler plant were not originally designed for high preheat temperatures and a maximum increase of 50ºC is usually the most that can be tolerated. Modern burners are available that can stand much higher temperatures. Therefore it is possible to consider installing a heat exchanger in the exit flue as an alternative to an economiser, although this is likely to be a less efficient method than preheating boiler feedwater. Energy saving potential of preheating combustion air Boiler efficiency can be increased by 1% by raising the combustion air temperature by 20ºC although the savings achieved will depend on the type of system installed. Ducting hot air down from the top of the boilerhouse will typically provide savings of up to 1%, while drawing combustion air over or through the boiler casing can provide savings of up to 2%.

11. Heat Exchangers Hi temperature and hi pressure unites designs for your specific applications. We design and manufacture steam to water and water to water shell & tube type heat exchangers and U tube type tank heaters (U tube heat exchangers). Features: • Shell and tube heat exchangers • Carbon steel, copper, cupro-nickel or stainless steel tubes • Shells and channels in carbon steel or stainless steel • Tube bundles as per your requirements • ASME Section VIII construction • Custom exchangers per customer specification • Fully packaged units, with valves, trim, circulators, etc.

12. Our whole list of Products are: Steam, Hot Water & Thermal Oil Boilers (Waste heat recovery and direct fired) Flue Gas Diverter Dampers Flue Gas Shut-Off Valves Heat Exchangers (Shell n Tube and U Type Tank Heaters) Air Heaters (Heat Exchangers) Hot Water Heaters / Hot Water Generators (Atmospheric Fired & Forced Draft) Chemical Feeders Expansion & Compression Tanks Air Separators Economizers Water Pressure Boosters Hot Water Generation and Storage System Applications Aras Our cost-effective energy/ heating solutions are widely appreciated by our domestic clients. Our wide range of boilers, heat exchangers, etc. caters to the needs of various industries such as: Food Industries Civil Construction Industry Pharmaceutical Industry Ship Building Industry Petroleum Industry Catering Industry Timber Industry Metal Industry Textile Industry Rubber Industry Paper and Printing Industry Chemicals/ Dyestuff Industry & etc.

13. Contact Us Thermo Tech Engineering +92-21-35120840, +92-342-2258884 or email us on [email_address] or visit our website http://tte.com.pk