The Green Machine- HengLi Creates a More Environmentally Friendly Furnace

      As the cost for crude oil and energy consumption increases, many companies are looking for ways to cut down on their costs. One way to do so is to focus on taking their highest energy intensive equipment, such as furnaces, and making them more environmentally, as well as wallet, friendly. In order to tackle this challenge, HengLi devised a simple math problem to not only to reduce energy consumption, but reduce the amount of materials used as well.

HengLi's Green Furnace- HSK 3505-0711 

      In order to evaluate a problem as large as high energy consumption, one must step back and take a more holistic view of the problem. One must consider not only how much energy is being used but why that much is being used. For that reason, the idea reducing energy consumption in furnaces gets broken down into two separate categories- dealing with materials and processes, or changing the equipment itself. 

      The material used and processes to create them highly depend on the end product's desired qualities and well as quantity. The process used within a furnace itself varies. Two of the most common processes include low firing temperature techniques and a fast fire method, each with their own benefits. The low firing technique is able to use less heat, and therefore less energy and resources in order to create a product. The fast fire furnaces ad able to decrease the time materials spend in the furnace and are able to conserve energy in that manner. The materials themselves can be altered in order to decrease furnace time. For example, using a glass powder and clay mix can reduce energy consumption by up to 40%!

      The manufacturers of HengLi furnaces have also looked into ways of improving energy efficiency within the furnace. Improvements in their furnaces are based off of the Simplified Model of Furnace Heat Loss that they developed which consists of the following variables:
          P: energy consumption of the furnace
          T: relative temperature of the heating elements to the surrounding environment
          T₁: relative surface temperature of the furnace body to the surrounding                        environment 
          R₁: insulation layer’s thermal resistant
          R₂: thermal resistance between furnace body and the surrounding environment
          C: system thermal capacity, which includes all the insulation and construction           material
          I₁: heat loss due to the load and its fixture or carrier
          I₂: other heat losses besides I1, like those from insulation layers, door and T.C           holes etc. 

      Through manipulating these variables in a series of simple mathematical equations, HengLi was able to develop a series of principles for energy saving. One of the many equations is:

P=T(T/(R₁+ R₂)+ I₁+I₂) + f(C,t)= (T-T₁)2/R₁+T₁²/ R₂+T(I₁+I₂)+f(C,t)

where f(C,t) is the rate of energy absorption of the furnace system and is set to approach zero over time. This also relays the information that R2 is directly proportional to the furnace's surface area and inversely proportional to the air's thermal conductivity. Another equation that was derived using these variables is one determining the difference between the energy consumptions of various furnaces, as follows:

P_s-P_c=(T-T₁)²/R₁+T₁ ²(R_2s+T(I₁+I₂)+f(Cs, t)-(T-T₁)²/R₁+T₁ ²(R_2s+T(I₁+I₂)+f(C_c, t)

=T₁²(1/R_2s-1/R_2c)+f(C_s,t)-f(C_c, t)

where the subscript s refers to the green furnace while the subscript c refers to a conventional furnace. After plugging in value for various models, the total equals a value below zero, inferring that the energy consumption of the green furnaces are lower than those of e furnace that are not.

      These resulted in a few main goals- to reduce the the total surface area (by increasing insulation) and to reduce the heat capacity of the furnace as well as the energy needed for each furnace to reach working temperature. After applying these principles, on-site testing proved that the new furnaces could save up to 20% energy for continuous furnaces and up to 40% for batch furnaces. 

 Sectional view of the mouth of the improved furnaces

      In addition to these main factors, one must also pay close attention to the specific furnace they are working with. For example, in larger furnaces, one must also look at variables such as heat lost from between insulation layers, the furnace door and the T.C. hole and therefore efficiency can be increased based on specific sizes and models. 

     Contact your nearest HengLi representative for more specific details on how to obtain or update your furnace to a more environmentally friendly furnace.