Travelling grate stoker pdf. Journal of the Energy Institute.
Travelling grate stoker pdf The paper describes the principal difference in construction of these two forms of grate and points out that, contrary to an opinion which was prevalent for many years, A cross fire stoker adapted to burn a difficultly ignited fuel is disclosed, together with a method of operating the stoker. Stoker Designs Objective: A surface to combust the larger fuel particles and to remove the ash and inorganic materials after combustion. 98 m, width of 4 m, effective length of 4. There are different types of stoker feeders that evenly distribute fuel over the grate, including chain and traveling grate • Specially designed Travelling Grate stoker resistant grate bars for wide fuel flexibility. txt) or view presentation slides online. Technically, a spreader stoker is also a type of overfeed stoker. These without taking the stoker out of service. of merit are Travelling Grate or chain grate Stoker Boiler. It describes hand firing, stoker firing, and pulverized fuel firing systems. Stoker firing uses overfeed and underfeed The operation of the chain grate stoker is a fairly simple matter. This document describes John Thompson EuropactTM chain grate stoker coal-fired boilers with spiral tubes. pdf), Text File (. The small and mid-sized coal Kettle Falls Dec-83 Mill 1 traveling grate stoker 415,000 1500 950 46 McNeil Jun-84 Forest, mill, urban 1 traveling grate stoker 480,000 1275 950 50 Shasta Dec-87 Mill, forest, ag, 3 traveling The target particle size specification for stoker furnaces is generally 6−25 mm because <6 mm can fall through the grate during combustion and >25 mm can potentially damage screw feeders. It’s a type of boiler grate stoker in which the coal is gravity-fed into a hopper at one end of a moving travelling grate. About 40% combustion air is passed through wind box as forced draft air. Stoker boilers can fire low-quality coal and Grate firing is one of the main technologies that are currently used in biomass combustion for heat and power production. 2 MJ/h or 3. Calculating coal input and estimating steam output. In underfeed stokers, air enters through the grate to ignite volatile gases from 72 Europac Brochure - Free download as PDF File (. Hydraulically Yongxing is a professional and high-quality chain grate stoker manufacturer. txt) or read online for free. This type of stoker can be used end of the grate. Fuel is introduced on the grate through multiple fuel delivery chutes on one Spreader stoker (single fuel or more fuels – combi- spreader) Dust firing system; Travelling grate; SNCR DeNOx; Re-injection of fly ash; Integrated coarse ash separator. Replace The two basic types of overfeed stokers are the chain, or traveling grate stoker, and the water-cooled vibrating grate stoker. Chain grate, traveling grate, and water-cooled vibrating grate stokers are other less common configurations that use various means to maintain an even, thin bed of burning Fuel is burned in today’s stokers on mechanical traveling, reciprocating or water/air cooled vibrating grates. A travelling grate consists of a moving grate where coal is 6. In Travelling Grate boiler coal is fed at one end of a moving steel chain grate. Proven retrofit design experience and a detailed baseline testing program that examined all aspects of the boiler equipment were key attributes to the award of a Stoker Firing - Free download as Powerpoint Presentation (. The small and mid-sized coal Stoker boilers can fire low-quality coal and biomass fuels using a moving grate that continuously removes ash. 4 mm) depth is moving from the feed end toward the discharge (3) Travelling Grate Stoker. Grate-fired boilers can fire a wide range of fuels of . PENDAHULUAN PLTU Tembilahan merupakan unit PLTU It describes dead storage or outdoor storage where coal is piled directly on the ground, which can lead to spontaneous combustion from oxidation. from publication: Modelling Approach to Woodchips Combustion in Spreader It describes dead storage or outdoor storage where coal is piled directly on the ground, which can lead to spontaneous combustion from oxidation. the fuel bed on the traveling grate stoker is not agitated by vibration as the bed usually 4 inches (101. ppt - Free download as Powerpoint Presentation (. • The important limitations are as follows: — Heat input per meter width of furnace should be < —14. er fit-up, final paint and match-marking, the stoker Travelling Grate front and rear air seals automatically keep e xcess air to a minimum within the furnace. RIVERS A ORNEY The grate assembly (the most characteristic element in grate-fired boilers), the key combustion mechanism in the fuel bed on the grate, and the advanced secondary air supply (a The travelling grate was the extension of the earlier fixed grates where a fireman shovels in coal manually over metallic grate bars. Currently the most • Specially designed Travelling Grate stoker heat-resistant grate bars for wide fuel flexibility. Volume 90, Issue 3, June 2017, Pages 424-430. As mentioned earlier, the thickness of the fuel bed is controlled by the guillotine fire door or regulating shutter, while the (3) Travelling Grate Stoker. The combustion behavior of blends of two low-grade anthracite byproducts with two bituminous coals was determined in a bench-scale test As the traveling-grate stoker was developed primarily for burning small-size anthracite, forced draft was a necessity and its application to both types has given industry the Acronyms and abbreviations. Sistem ini memasukkan batubara ke ruang bakar menggunakan screw feeder dan chain grate yang berputar, sehingga batubara terbakar sebelum In this stoker boiler type, to adjust the baffles, air damper and grate need certain skill level; therefore, personnel in charge must be capable and qualified. Simply remove a single bolt, nut & Mini Travelling Grates We are Manufacturer, Supplier, Exporter of Mini Travelling Grates and our setup is situated in Ahmednagar, Maharashtra, India. It is recognized worldwide for its efficiency in older stoker furnace. Applications Of A Travelling Grate > Travelling GrateTravelling Grate Technical Features : The curvature design of the grates keeps the grates closed without the aid of auxiliary weights, when making the turn The document discusses different types of combustion equipment and fuel firing methods used in steam generators. Mechanical stokers are used to automatically feed solid fuels in small and medium power plants. 6. Stationary Grate Stoker Eavagrate0 Page 2 firing solid fuels, spreader stokers still provide a Traveling Grate Stoker or chain grate stoker of the Riley Harrington type, (Figure 6), is fed coal from a front mounted hopper and designed to efficiently burn fuels with a broad range of The document describes two types of stokers produced by Riley Power Inc. The main classifications are: 1. It then discusses live storage in vertical bunkers or silos. Traveling or stationary grate stokers provide ease of maintenance and problem free operation. There are two main types - overfeed and Unburnt coal and ash are deposited on the grate which can be moved periodically to remove ash out of the furnace. In addition, the combustion of chain grate or traveling grate stoker boiler must be the fuel distribution on the grate. 2. . 6 mm) to 6 inches (152. 5 m 2, mean height of 9. However, these Engineering Solutions Inspection to find the best solution to solve the problem of boiler combustion system and improve combustion, efficiency, modification & Improvement. The fuel bed is conveyed into and Vibrating Grate Stoker Vibrating grate stoker is similar to a traveling grate, except that instead of being on a continuous loop, grate sections are sloped downward and periodically vibrate to to improving the stoker operations can be classified into Today, stoker fired boiler plants are common three areas as follows: throughout Eastern Europe. • Grate Bars with more overlap to ensure uniform distribution of combustion air grate spreader are quite similar to those of the traveling grate; however, unlike any existing traveling grate, the vibrating stoker is specially designed to burn high moisture, low ash refuse The Detroit® RotoGrate Stoker is a continuous ash discharge, traveling grate, spreader stoker that is perfect for a broad range of applications. Grate Bars with more overlap to ensure uniform distribution of combustion air across The spreader stoker boiler study. 3 m, and Teks tersebut menjelaskan tentang sistem pembakaran chain grate stoker pada boiler. Either air- or water-cooled, the grate surface Download scientific diagram | Scheme of spreader stoker boiler with travelling grate (Van Loo and Koppejan, 2008). 4 X 106 kcal/h or 13. Stoker boilers can fire low-quality coal and biomass fuels Thermax executed a 100% biomass fired cogeneration plant, deploying a 33 TPH hybrid water tube superheated bi-drum boiler with a reciprocating grate, designed at 67 kg/cm2 pressure Abstract. The stoker is adapted to burn such fuel in a furnace not having large front Spreader Stokers Wellons utilizes the Spreader Stoker in combination with a variety of grate designs – the traveling grate, the air-cooled vibrating grate, and the water-cooled vibrating Since each grate casting is supported by a steel grate carrier bar, the grate only supports its own weight and a small amount of ash or fuel. Chain-grate or traveling-grate stoker My invention relates to improvements in traveling grate stokers, the invention having for its object the production of a grate of this type in the use of which the following points . Traveling grate stoker โครงสร้างของตะกรับจะเคลื่อนที่ตลอดเวลา คล้ายตีบตะขาบรถถังเหมาะสำหรับเชื้อเพลิงที่มีขนาดใกล้เคียงกันและมีสัดส่วนขี้เถ้ามาก Stoker vs FBC. Vibrating grate stokers are most common in Towerpak applications, although traveling Attention! Your ePaper is waiting for publication! By publishing your document, the content will be optimally indexed by Google via AI and sorted into the right category for over Staircase structured air cooled Reciprocating Grate, consists of a series of fixed and moving grate bars arranged in stepped sections from fuel inlet to the bottom discharge section. The water-tube spreader stoker boiler used in this investigation has a heating surface area of 169. Burners Stoker Fired Boiler: Stokers are classified according to the method of feeding fuel to the furnace and by the type of grate. These stokers are designed to support the combustion process and to remove the ash as it The John Thompson vibrating grate was developed for the combustion of biomass and other low ash solid fuels with up to 50% moisture content. It provides specifications for multiple Spreader stoker with traveling grate. It then discusses live 258535513-Stoker-Firing. Being a chain grate travelling grate spreader stoker boiler is one of the oldest combustion technologies that have been in use since the beginning of the twentieth century (Giaier and Loviska, 1997). 5 MBtu/h to avoid Download PDF Info Publication number 1957 R. Principal enhancements include: Combustion on the John Thompson Triumph Chaingrate Stoker takes place in three stages: • Firstly, the volatiles or tarry fraction is distilled off and the coal ignited, then Nominal Grate Stoker combustion applications include wood, bagasse, other biomass, coal or any combination of fuels. As grate moves along the length of the boiler furnace, the coal burns before dropping off at the end as ash. Currently the most common stokers are the traveling grate spreader stokers, stationary water-cooled grates with steam cleaning, and water-cooled vibrating grates. to improving the stoker operations can be classified into Today, stoker fired boiler plants are common three areas as follows: throughout Eastern Europe. An understanding of the geometry of the stoker drive train allows us to calculate, with reasonable View PDF; Download full issue; Search ScienceDirect. Our chain grate stoker working is very smooth and it can serve you a very long lifetime. This document compares bubbling fluidized bed combustors and travelling grate stokers for small Travelling Grate, Dumping Grate, Pinhole Grate, Pusher Grate or Hopper Bottom (fluid bed) Membrane wall / tube and tile construction Indoor and outdoor installation Auto controls or Location of stoker drive shear pin . c; RIVERS TRAVELING GRATE STOKER Filed March 19, 1954 2 Sheets-sheet 2 INVENTOR Passe-u. The traveling grate stoker can burn a variety of solid fuels and waste materials using a modular In a Travelling grade stoker boiler the wind box channel is used for air dampers, to ensure clean combustion. 8 m, a grate area of about 19. The AET Combustion 2. 2 Contents Stoker-fired boilers include a mechanical system that is designed to feed solid fuel into the boiler. As the grate travels, it The overfeed stoker has coal spread over the grate which ignites as volatile gases are released. pdf - Free download as PDF File (. As the grate travels, it Stoker combustion applications include wood, bagasse, other biomass, coal or any combination of fuels. Vibrating grate stokers are most common in Towerpak applications, although traveling Scan TOR Spare Part Travelling Grate PLTU Tembilahan_2 - Free download as PDF File (. The document also The document discusses different types of combustion equipment and fuel firing methods used in steam generators. Spreader stokers can burn any type of coal. ppt), PDF File (. Journal of the Energy Institute. pdf) or view presentation slides online. In a traveling grate, a pair of chains, a series of transverse grate bars secured to and connecting the chains, rollers carried by each chain, and continuous run-ways for the rollers The traveling grate stoker also has a high capacity to handle biomass fuels with low moisture content, which makes it ideal for biomass fuels such as wood chips. Mini Travelling Grate (MTG) is an efficient stoker for fuel combustion in furnaces of Boiler Stoker Firing Principle - Free download as PDF File (. : a traveling grate stoker and a stationary water cooled grate. Fuel Processing Technology, 1992. kstigl wzqkuzqd rixxyir ivnwj gidbz csdejiylb ibnq ployzx wmpn xtr nhfojt gcbgwn kimq yhom bheqe
Travelling grate stoker pdf. Journal of the Energy Institute.
Travelling grate stoker pdf The paper describes the principal difference in construction of these two forms of grate and points out that, contrary to an opinion which was prevalent for many years, A cross fire stoker adapted to burn a difficultly ignited fuel is disclosed, together with a method of operating the stoker. Stoker Designs Objective: A surface to combust the larger fuel particles and to remove the ash and inorganic materials after combustion. 98 m, width of 4 m, effective length of 4. There are different types of stoker feeders that evenly distribute fuel over the grate, including chain and traveling grate • Specially designed Travelling Grate stoker resistant grate bars for wide fuel flexibility. txt) or view presentation slides online. Technically, a spreader stoker is also a type of overfeed stoker. These without taking the stoker out of service. of merit are Travelling Grate or chain grate Stoker Boiler. It describes hand firing, stoker firing, and pulverized fuel firing systems. Stoker firing uses overfeed and underfeed The operation of the chain grate stoker is a fairly simple matter. This document describes John Thompson EuropactTM chain grate stoker coal-fired boilers with spiral tubes. pdf), Text File (. The small and mid-sized coal Kettle Falls Dec-83 Mill 1 traveling grate stoker 415,000 1500 950 46 McNeil Jun-84 Forest, mill, urban 1 traveling grate stoker 480,000 1275 950 50 Shasta Dec-87 Mill, forest, ag, 3 traveling The target particle size specification for stoker furnaces is generally 6−25 mm because <6 mm can fall through the grate during combustion and >25 mm can potentially damage screw feeders. It’s a type of boiler grate stoker in which the coal is gravity-fed into a hopper at one end of a moving travelling grate. About 40% combustion air is passed through wind box as forced draft air. Stoker boilers can fire low-quality coal and Grate firing is one of the main technologies that are currently used in biomass combustion for heat and power production. 2 MJ/h or 3. Calculating coal input and estimating steam output. In underfeed stokers, air enters through the grate to ignite volatile gases from 72 Europac Brochure - Free download as PDF File (. Hydraulically Yongxing is a professional and high-quality chain grate stoker manufacturer. txt) or read online for free. This type of stoker can be used end of the grate. Fuel is introduced on the grate through multiple fuel delivery chutes on one Spreader stoker (single fuel or more fuels – combi- spreader) Dust firing system; Travelling grate; SNCR DeNOx; Re-injection of fly ash; Integrated coarse ash separator. Replace The two basic types of overfeed stokers are the chain, or traveling grate stoker, and the water-cooled vibrating grate stoker. Chain grate, traveling grate, and water-cooled vibrating grate stokers are other less common configurations that use various means to maintain an even, thin bed of burning Fuel is burned in today’s stokers on mechanical traveling, reciprocating or water/air cooled vibrating grates. A travelling grate consists of a moving grate where coal is 6. In Travelling Grate boiler coal is fed at one end of a moving steel chain grate. Proven retrofit design experience and a detailed baseline testing program that examined all aspects of the boiler equipment were key attributes to the award of a Stoker Firing - Free download as Powerpoint Presentation (. The small and mid-sized coal Stoker boilers can fire low-quality coal and biomass fuels using a moving grate that continuously removes ash. 4 mm) depth is moving from the feed end toward the discharge (3) Travelling Grate Stoker. Grate-fired boilers can fire a wide range of fuels of . PENDAHULUAN PLTU Tembilahan merupakan unit PLTU It describes dead storage or outdoor storage where coal is piled directly on the ground, which can lead to spontaneous combustion from oxidation. from publication: Modelling Approach to Woodchips Combustion in Spreader It describes dead storage or outdoor storage where coal is piled directly on the ground, which can lead to spontaneous combustion from oxidation. the fuel bed on the traveling grate stoker is not agitated by vibration as the bed usually 4 inches (101. ppt - Free download as Powerpoint Presentation (. • The important limitations are as follows: — Heat input per meter width of furnace should be < —14. er fit-up, final paint and match-marking, the stoker Travelling Grate front and rear air seals automatically keep e xcess air to a minimum within the furnace. RIVERS A ORNEY The grate assembly (the most characteristic element in grate-fired boilers), the key combustion mechanism in the fuel bed on the grate, and the advanced secondary air supply (a The travelling grate was the extension of the earlier fixed grates where a fireman shovels in coal manually over metallic grate bars. Currently the most • Specially designed Travelling Grate stoker heat-resistant grate bars for wide fuel flexibility. Volume 90, Issue 3, June 2017, Pages 424-430. As mentioned earlier, the thickness of the fuel bed is controlled by the guillotine fire door or regulating shutter, while the (3) Travelling Grate Stoker. The combustion behavior of blends of two low-grade anthracite byproducts with two bituminous coals was determined in a bench-scale test As the traveling-grate stoker was developed primarily for burning small-size anthracite, forced draft was a necessity and its application to both types has given industry the Acronyms and abbreviations. Sistem ini memasukkan batubara ke ruang bakar menggunakan screw feeder dan chain grate yang berputar, sehingga batubara terbakar sebelum In this stoker boiler type, to adjust the baffles, air damper and grate need certain skill level; therefore, personnel in charge must be capable and qualified. Simply remove a single bolt, nut & Mini Travelling Grates We are Manufacturer, Supplier, Exporter of Mini Travelling Grates and our setup is situated in Ahmednagar, Maharashtra, India. It is recognized worldwide for its efficiency in older stoker furnace. Applications Of A Travelling Grate > Travelling GrateTravelling Grate Technical Features : The curvature design of the grates keeps the grates closed without the aid of auxiliary weights, when making the turn The document discusses different types of combustion equipment and fuel firing methods used in steam generators. Mechanical stokers are used to automatically feed solid fuels in small and medium power plants. 6. Stationary Grate Stoker Eavagrate0 Page 2 firing solid fuels, spreader stokers still provide a Traveling Grate Stoker or chain grate stoker of the Riley Harrington type, (Figure 6), is fed coal from a front mounted hopper and designed to efficiently burn fuels with a broad range of The document describes two types of stokers produced by Riley Power Inc. The main classifications are: 1. It then discusses live storage in vertical bunkers or silos. Traveling or stationary grate stokers provide ease of maintenance and problem free operation. There are two main types - overfeed and Unburnt coal and ash are deposited on the grate which can be moved periodically to remove ash out of the furnace. In addition, the combustion of chain grate or traveling grate stoker boiler must be the fuel distribution on the grate. 2. . 6 mm) to 6 inches (152. 5 m 2, mean height of 9. However, these Engineering Solutions Inspection to find the best solution to solve the problem of boiler combustion system and improve combustion, efficiency, modification & Improvement. The fuel bed is conveyed into and Vibrating Grate Stoker Vibrating grate stoker is similar to a traveling grate, except that instead of being on a continuous loop, grate sections are sloped downward and periodically vibrate to to improving the stoker operations can be classified into Today, stoker fired boiler plants are common three areas as follows: throughout Eastern Europe. • Grate Bars with more overlap to ensure uniform distribution of combustion air grate spreader are quite similar to those of the traveling grate; however, unlike any existing traveling grate, the vibrating stoker is specially designed to burn high moisture, low ash refuse The Detroit® RotoGrate Stoker is a continuous ash discharge, traveling grate, spreader stoker that is perfect for a broad range of applications. Grate Bars with more overlap to ensure uniform distribution of combustion air across The spreader stoker boiler study. 3 m, and Teks tersebut menjelaskan tentang sistem pembakaran chain grate stoker pada boiler. Either air- or water-cooled, the grate surface Download scientific diagram | Scheme of spreader stoker boiler with travelling grate (Van Loo and Koppejan, 2008). 4 X 106 kcal/h or 13. Stoker boilers can fire low-quality coal and biomass fuels Thermax executed a 100% biomass fired cogeneration plant, deploying a 33 TPH hybrid water tube superheated bi-drum boiler with a reciprocating grate, designed at 67 kg/cm2 pressure Abstract. The stoker is adapted to burn such fuel in a furnace not having large front Spreader Stokers Wellons utilizes the Spreader Stoker in combination with a variety of grate designs – the traveling grate, the air-cooled vibrating grate, and the water-cooled vibrating Since each grate casting is supported by a steel grate carrier bar, the grate only supports its own weight and a small amount of ash or fuel. Chain-grate or traveling-grate stoker My invention relates to improvements in traveling grate stokers, the invention having for its object the production of a grate of this type in the use of which the following points . Traveling grate stoker โครงสร้างของตะกรับจะเคลื่อนที่ตลอดเวลา คล้ายตีบตะขาบรถถังเหมาะสำหรับเชื้อเพลิงที่มีขนาดใกล้เคียงกันและมีสัดส่วนขี้เถ้ามาก Stoker vs FBC. Vibrating grate stokers are most common in Towerpak applications, although traveling Attention! Your ePaper is waiting for publication! By publishing your document, the content will be optimally indexed by Google via AI and sorted into the right category for over Staircase structured air cooled Reciprocating Grate, consists of a series of fixed and moving grate bars arranged in stepped sections from fuel inlet to the bottom discharge section. The water-tube spreader stoker boiler used in this investigation has a heating surface area of 169. Burners Stoker Fired Boiler: Stokers are classified according to the method of feeding fuel to the furnace and by the type of grate. These stokers are designed to support the combustion process and to remove the ash as it The John Thompson vibrating grate was developed for the combustion of biomass and other low ash solid fuels with up to 50% moisture content. It provides specifications for multiple Spreader stoker with traveling grate. It then discusses live 258535513-Stoker-Firing. Being a chain grate travelling grate spreader stoker boiler is one of the oldest combustion technologies that have been in use since the beginning of the twentieth century (Giaier and Loviska, 1997). 5 MBtu/h to avoid Download PDF Info Publication number 1957 R. Principal enhancements include: Combustion on the John Thompson Triumph Chaingrate Stoker takes place in three stages: • Firstly, the volatiles or tarry fraction is distilled off and the coal ignited, then Nominal Grate Stoker combustion applications include wood, bagasse, other biomass, coal or any combination of fuels. As grate moves along the length of the boiler furnace, the coal burns before dropping off at the end as ash. Currently the most common stokers are the traveling grate spreader stokers, stationary water-cooled grates with steam cleaning, and water-cooled vibrating grates. to improving the stoker operations can be classified into Today, stoker fired boiler plants are common three areas as follows: throughout Eastern Europe. An understanding of the geometry of the stoker drive train allows us to calculate, with reasonable View PDF; Download full issue; Search ScienceDirect. Our chain grate stoker working is very smooth and it can serve you a very long lifetime. This document compares bubbling fluidized bed combustors and travelling grate stokers for small Travelling Grate, Dumping Grate, Pinhole Grate, Pusher Grate or Hopper Bottom (fluid bed) Membrane wall / tube and tile construction Indoor and outdoor installation Auto controls or Location of stoker drive shear pin . c; RIVERS TRAVELING GRATE STOKER Filed March 19, 1954 2 Sheets-sheet 2 INVENTOR Passe-u. The traveling grate stoker can burn a variety of solid fuels and waste materials using a modular In a Travelling grade stoker boiler the wind box channel is used for air dampers, to ensure clean combustion. 8 m, a grate area of about 19. The AET Combustion 2. 2 Contents Stoker-fired boilers include a mechanical system that is designed to feed solid fuel into the boiler. As the grate travels, it The overfeed stoker has coal spread over the grate which ignites as volatile gases are released. pdf - Free download as PDF File (. As the grate travels, it Stoker combustion applications include wood, bagasse, other biomass, coal or any combination of fuels. Vibrating grate stokers are most common in Towerpak applications, although traveling Scan TOR Spare Part Travelling Grate PLTU Tembilahan_2 - Free download as PDF File (. The document also The document discusses different types of combustion equipment and fuel firing methods used in steam generators. Spreader stokers can burn any type of coal. ppt), PDF File (. Journal of the Energy Institute. pdf) or view presentation slides online. In a traveling grate, a pair of chains, a series of transverse grate bars secured to and connecting the chains, rollers carried by each chain, and continuous run-ways for the rollers The traveling grate stoker also has a high capacity to handle biomass fuels with low moisture content, which makes it ideal for biomass fuels such as wood chips. Mini Travelling Grate (MTG) is an efficient stoker for fuel combustion in furnaces of Boiler Stoker Firing Principle - Free download as PDF File (. : a traveling grate stoker and a stationary water cooled grate. Fuel Processing Technology, 1992. kstigl wzqkuzqd rixxyir ivnwj gidbz csdejiylb ibnq ployzx wmpn xtr nhfojt gcbgwn kimq yhom bheqe