The main components of the catalytic combustion equipment include heat exchangers, catalyst beds, electric heaters, combustion chambers, and regenerators, among others. The heating tubes heat the catalytic combustion equipment, providing the necessary temperature for activated carbon adsorption under the action of the fan. The treated waste gas enters the interior of the catalytic combustion equipment, where it is oxidized and decomposed into smaller molecular compounds under certain temperature conditions due to the action of the catalyst bed. Energy saving and environmental protection are achieved through the heat exchanger.
Catalytic combustion equipment produced by manufacturers is nearly suitable for all industrial production processes emitting odor compounds, such as mechanical and electrical, home building materials, etc. When using catalytic combustion equipment for waste gas treatment, it is crucial to consider the differences in concentration and air volume.
By filtering the valuable waste gas, which is concentrated, low in volume, and high in temperature, through activated carbon in a fire-retardant dust filter, the gas then enters a plate-type heat exchanger for energy exchange, further increasing the temperature of the waste source. After entering the preheater, the temperature is boosted again. This is when the catalytic reaction begins, and the valuable waste gas starts to decompose, releasing energy in the process. We then directly heat the waste gas source, raising the gas temperature to a suitable level for catalytic reaction. If the temperature is correct, the gas will enter the combustion chamber and undergo a more advanced decomposition. Subsequently, the gas is purified before being exhausted through a fan into the sky.
We are opting for catalytic combustion units that are easy to clean and replace. Reactors should generally be designed with modular drawer structures for easy cleaning and replacement of the catalyst carrier. When selecting catalytic combustion setups, we also need to consider the sufficiency of auxiliary fuel and combustion support. Natural gas, fuel oil, and electric heating can all serve as auxiliary fuels. Purified gas is typically used for combustion support, but if it's not suitable, air is added as an alternative.
When selecting catalytic combustion settings, we must also consider whether the conversion rate is satisfactory. As catalytic combustion is an exothermic reaction, we should all strive to carry out this reaction at an optimal temperature to achieve a favorable conversion rate. However, the operating temperature we use is often constrained by certain conditions, such as the thermal stability of the catalyst, the availability of high-temperature materials, the supply of thermal energy, and the presence of side reactions. Therefore, in our production practice, we need to choose what is necessary for us.
When selecting a design, it is essential to fully consider the use of catalysts. Catalysts are substances that can affect the rate of a chemical reaction and do not alter their own chemical properties before or after the reaction. The general composition of catalysts includes catalytic active materials and catalytic carriers. Metals or metal oxides are typically the catalytic active materials, with platinum, palladium, and rhodium being common components of precious metal catalysts. Copper, chromium, nickel, vanadium, manganese, iron, cobalt, and their oxides are the main components of ordinary metal catalysts.
During the operation of catalytic combustion equipment, it is essential to optimize control measures. Before waste gases enter the furnace chamber, remove as much moisture as possible from the inlet spray tower to reduce the heat required for vaporization. Additionally, optimize the timing of air intake and exhaust, maintain the combustion chamber temperature, and enhance valve sealing. Furthermore, a combination of a metering pump and an evaporator can be used in the intake air duct to manually control the evaporation of non-volatile organic compounds (VOCs) from waste solvents. This can increase VOC concentration when the VOC levels in the waste gases are low, enabling normal combustion without fuel consumption, thereby reducing fuel consumption. Generally, maintaining normal operation requires much lower VOC concentrations than the lower explosive limit. VOC evaporation can also be adjusted or shut off at any time based on the furnace temperature, making the associated risks largely controllable.
Our catalytic combustion equipment boasts impressive exhaust gas purification rates and excellent heat recovery efficiency, which helps save energy consumption during operation. However, without proper management, excessive energy consumption can increase production costs for the enterprise. So, how can we optimize the energy consumption of the catalytic combustion equipment? Before addressing the problem, we must first understand the root causes and tailor our solutions accordingly. The main energy consumers in the operation of catalytic combustion equipment are electricity and fuel. Due to the fluctuating exhaust gas volume and concentration, as well as poor control of workshop exhaust, it is necessary to frequently replenish fuel to maintain the combustion chamber temperature during startup and operation.
Thermal storage ceramics play a crucial role in fuel consumption, with energy consumption typically measured by the VOC concentration required to maintain normal operation without fuel supplementation—the lower the value, the lower the energy consumption. Effective catalytic combustion equipment can achieve a value of up to 450×10-6 mg/L. Heat loss is primarily due to exhaust gas carryover and surface heat dissipation, with the former related to exhaust gas volume and the temperature difference between the inlet and outlet. Lower exhaust gas temperatures and larger temperature differences between the inlet and outlet result in lower energy consumption. Surface heat dissipation is reflected in the temperature difference between the cabinet surface and the environment; better insulation results in smaller temperature differences and less heat loss. Additionally, energy consumption may also be related to poor insulation in localized areas and high-temperature gas leaks.
Once the cause is identified, specific solutions must be proposed accordingly. When enterprises choose a catalytic combustion incinerator to treat VOCs, the manufacturer needs to comprehensively consider the wind volume and reference values of the useful substance concentration. Selecting an excessively large wind volume results in low VOCs concentration and high operational energy consumption; conversely, selecting an insufficient wind volume leads to high VOCs concentration, which can easily cause backfire or flash explosion accidents in the furnace, and the high concentration of useful exhaust gas is also prone to explosion accidents during transportation due to static electricity, etc. Of course, alternative methods such as variable frequency control can be employed to adjust the fan wind volume based on production conditions, thereby reducing energy consumption.
