The Difference between Heat Insulation Materials and Thermal Insulation Materials

Strictly speaking, the concept of thermal insulation refers to the change of thermal energy of the object of concern (such as equipment, buildings, etc.), while the concept of thermal insulation, heat insulation, or thermal insulation refers to the heat flow or heat transfer of the heat source. Thermal insulation materials refer to materials that can block the transfer of heat flow, also known as thermal insulation materials (but not the same as thermal insulation materials). Thermal insulation materials can be divided into three categories: void heat insulation materials, heat reflective materials, and materials with both void heat insulation and heat reflective properties.

RS Ceramic Fiber Insulation Materials
RS Ceramic Fiber Insulation Materials

Insulation Materials

Insulation materials are materials or material complexes that are not easy to conduct heat and have significant resistance to heat flow. Their characteristics are: light weight, looseness, porosity, heat preservation, cold preservation, heat insulation, sound absorption, and sound elimination. Generally speaking, insulation materials include the first and third categories of materials mentioned above. Insulation materials can be divided into organic insulation materials (or organic thermal insulation materials) and inorganic insulation materials (or inorganic thermal insulation materials).

In industry idioms, insulation materials often refer to insulation materials suitable for temperatures below 600-700℃. In addition, the industry also refers to insulation materials suitable for low-temperature environments as “cold insulation materials”. Insulation materials suitable for high-temperature environments above 600-800℃ are called “refractory insulation materials“. Insulation materials have lower requirements for thermal conductivity values.

Insulation materials are often referred to as “thermal insulation materials” by people. Here, people do not strictly distinguish the subtle differences between different concepts.

The refractory industry and other industries often use the words “insulation” and “thermal insulation” to refer to lightweight and poorly conductive materials. However, the two are not used consistently and deserve to be reconsidered and unified. In the refractory industry, before the mid-1980s, “insulation materials” and “thermal insulation materials” were used interchangeably. Since then, the term “thermal insulation materials” has been gradually unified, so RS Kiln Refractory Factory will focus on the difference between thermal insulation and heat preservation below.

What is the Difference between Thermal Insulation and Heat Insulation?

  1. The concept of thermal insulation board and heat preservation board

Thermal insulation board refers to a board used to isolate heat transfer, generally referring to a board with a thermal conductivity of less than or equal to 0.065W/m•k, such as foam glass, polystyrene board, etc.

Thermal insulation board refers to a reasonable engineering material used to maintain the temperature inside and outside the building. It is usually made of materials with a thermal conductivity of less than or equal to 0.12W/m•k, such as extruded board, mineral wool board, etc.

  1. Differences between insulation board and heat preservation board

(1) Material properties

The thermal conductivity of insulation board is lower than that of heat preservation board, and the density of heat preservation board is higher than that of heat preservation board. Heat preservation board is generally a porous material with good air tightness, which can block water vapor penetration to a certain extent, but its bearing capacity for gravity load and wind pressure load is poor. The material used for heat preservation board is relatively hard, with high strength, and can withstand greater pressure.

(2) Application

Thermal insulation board is mainly used for moisture-proof, mildew-proof, anti-corrosion, fire-proof and sound-proof, and is also suitable for roof and wall insulation of industrial buildings and high-end residential buildings. The role of heat preservation board is more to improve the living environment of residential buildings, and is mainly used in the fields of exterior wall insulation, roof insulation, cold storage insulation, etc.

(3) Construction method

Thermal insulation board is mostly constructed by pasting, such as binding with polyurethane foam adhesive. It is generally more convenient to directly paste it with brick wall to achieve insulation. The insulation board needs to be installed by hanging, which is more troublesome, especially in high-rise buildings where construction safety issues need to be considered.

  1. Applicable situations

If the building needs to be moisture-proof, mildew-proof, anti-corrosion, fire-proof, sound-proof, etc., it is suitable to use insulation boards. Such as industrial buildings and high-end residences such as pharmaceutical factories, chemical plants, and food factories. If you need to improve the residential living environment, insulation boards are the first choice. It can effectively increase the temperature of the room and keep the indoor temperature stable, thereby reducing energy consumption.

Thermal Insulation Materials for Aluminum Electrolytic Cells

Aluminum electrolytic cell is the main thermal equipment for aluminum electrolysis production. Electrolytic aluminum is the process of converting aluminum in alumina into metallic aluminum. There is an outstanding problem in the aluminum electrolytic plant. The bottom of the tank is cold. Improvement measures include blocking the windows in the lower part of the two-story structure, laying bricks within the tank shell frame, and coating the outside of the tank with an insulation layer.

Aluminum electrolytic cells are divided into bottom type and bottomless type according to the structure of the tank. According to the shape of the tank shell, it is divided into square and rectangular. According to the anode structure, it is divided into a prebaked anode and a continuous self-baked anode. According to the conductive mode, it is divided into side conductive and upper conductive.

Aluminum Smelting Furnace
Aluminum Smelting Furnace

The lining materials used in aluminum electrolytic cell-related equipment include calcium silicate boards, clay-insulating refractory bricks, clay refractory bricks, and dry anti-seepage materials. Cathode carbon block, carbon paste, water glass asbestos putty, silicon nitride silicon carbide thermal insulation coating, etc. The heat insulation layer refractory material can be placed between the tank bottom and the asbestos board to increase the heat insulation. The thermal insulation performance is more than five times stronger than calcium silicate boards of the same thickness.

High-Temperature Thermal Insulation Coating for Aluminum Electrolytic Cells

High-temperature thermal insulation coating is processed from specially synthesized inorganic silicate solution, aluminum silicate fiber, heat-reflective material, and selected hollow ceramic beads. Water-based, environmentally friendly, non-toxic, and harmless. The characteristics of high-temperature thermal insulation coating products for aluminum electrolytic cells are as follows:

  1. Thermos bottle thermal insulation mechanism.
  2. The hollow ceramic beads in the coating greatly reduce heat convection.
  3. Inorganic film-forming substances with relatively low thermal conductivity.
  4. Sound insulation and noise reduction, fire-retardant, wear-resistant and pressure-resistant, insulation-resistant and puncture-resistant, acid and alkali-resistant, lightweight, easy construction, and long service life.
RS 500 Thermal Insulating Coating
RS 500 Thermal Insulating Coating

The curing principle of high-temperature thermal insulation coating for aluminum electrolytic cells:

Silicate coatings are composed of a variety of silicates and a small amount of organic and inorganic binders. Its curing principle: a special silicate solution acts as a gelling agent. Aggregation process:

  1. The condensation of silanol and the condensation between silanol and the aluminum hydroxyl group of the silicate. Form a three-dimensional skeleton network.
  2. Silicates are polymerized according to layered and framework molecular-level silicone groups. The mixed metal oxide acts as a space filler between the three-dimensional skeleton of the main body.

Application of High-Temperature Thermal Insulation Coating

  1. Surface painting. High-temperature molds and outer surfaces of injection molding machines. On the inner surface of high-temperature flues and exhaust pipes. Paint the thermal insulation surface of hot water tanks and dye vats.
  2. Ceramic production, ceramic roller kiln, refractory rotary kiln. Cement plant applications, cement rotary kiln, preheater, decomposition furnace.
  3. Steel plant applications, ring furnaces, heating furnaces, and quenching furnaces. Molten steel tundish. Blast furnace workshop steel structure insulation, coke oven.
  4. The inner wall of the furnace shell of the smelting furnace in the metallurgical copper industry. The inner wall of the electrolytic aluminum furnace (aluminum industry).
  5. The outer surface of the power plant turbine shell/shaft seal; and the outer surface of the steam pipe are painted. Petrochemical heating furnace, vacuum heating furnace, cracking furnace.
  6. The top of the boiling furnace is insulated and sealed. Industrial heating furnace. Vacuum furnace insulation.
  7. Driving cab (Crane Crane). Explosion-proof vehicles, asphalt vehicles, engineering vehicles, and military armored vehicle chassis.
  8. Spinning box, high-temperature oven surface. New energy batteries and intermediate frequency furnaces.
Calcium Silicate Board for Aluminum Electrolytic Cell
Calcium Silicate Board for Aluminum Electrolytic Cell

Calcium Silicate Board for Aluminum Electrolytic Cell

Calcium silicate board is a new type of building material, also called “calcium silicate board”, “calcium magnesium silicate board”, “MgO board”, etc. It is a composite building material made of a variety of materials and has multiple functions such as fire protection, waterproofing, sound insulation, heat preservation, and corrosion resistance. Calcium silicate boards can be widely used in various fields such as building walls, roofs, partitions, and floors. It has high economic and social benefits.

The main components of calcium silicate board are inorganic mineral fibers as reinforcing materials, and siliceous, calcium, and other materials as the main materials. These materials are made by high-temperature pressing after certain stabilization treatments. Calcium silicate board has good flexural strength, tensile strength, and compressive strength. At the same time, it also has multiple functions such as fire resistance, corrosion resistance, sound insulation, and heat preservation.

Calcium silicate boards also have a wide range of applications and can be used on walls, roofs, partitions, and floors. Calcium silicate board has the characteristics of water resistance, corrosion resistance, etc. Therefore it is widely used in relatively humid places.

Compared with traditional building materials, the installation process of calcium silicate boards is simpler and faster. When installing calcium silicate boards, you only need to install them directly on the frame, and few other materials are used. Therefore, no construction waste and pollutants will be generated. As a thermal insulation material, calcium silicate boards are also widely used in aluminum electrolytic cells.