Flue gas purification equipment

Flue gas purification equipment

The flue gas purification system is one of the key equipments for a waste incineration plant, because the flue gas generated during the waste incineration process contains a large amount of pollutants. If these pollutants are not controlled, it will cause secondary pollution of the waste incineration plant. The selection of an efficient flue gas purification system is the key to preventing the secondary pollution of waste incineration plants and the emission of flue gas.

The main pollutants produced during the incineration of waste are the following: Incomplete combustion products: by-products resulting from poor combustion, including carbon monoxide, carbon black, hydrocarbons, alkenes, ketones, alcohols, organic acids, and polymers. Dust: Inactive metal salts, metal oxides, or incompletely combusted materials in the waste. Acid gases: include hydrogen chloride, hydrogen halides (fluorine, bromine, iodine, etc., sulfur oxides), and phosphorus pentoxide and phosphoric acid. Heavy metal pollutants: including lead, chromium, mercury, cadmium, arsenic and other elemental states, oxides and chlorides. Dioxins: Dioxins and furans are included.

At present, the development of waste incineration flue gas purification technology can be divided into wet, dry, and semi-dry methods depending on whether it generates wastewater and the form in which the absorbent is added. Due to the high investment cost of the wet method, the waste water produced contains heavy metal elements and will cause secondary pollution. Therefore, this technology is rarely used in domestic waste incineration exhaust gas treatment systems. Although the spray drying technique was very popular in the 1980s, due to the high-speed rotation characteristics of the high-speed rotating spray head used in its equipment, localization is still in the experimental stage and has not been effectively applied, so there is uncertainty; In addition, due to the instability of the quality of the lime slurry, it is very easy to cause the problems of nozzle and pipeline clogging. In addition, the system also has the defects that the absorbent cannot be recycled, and the ratio of calcium to sulfur is relatively high.

In order to achieve stable operation, reduce costs, and meet more and more stringent environmental protection requirements, this project uses a semi-dry flue gas treatment system with an independent humidity control device, ie, "quench tower + fluidized bed reaction tower + pre-precipitator + activated carbon Flue gas purification system with injection device + high efficiency bag filter

The focus is on the control of pollutants generated during the incineration of waste and dust treatment. By analyzing the causes, types and components of pollutants, combined with experiments, research, engineering applications and corresponding monitoring data, a waste incineration flue gas treatment device suitable for China's national conditions was developed. Combined with the boiler combustion method and combustion control, the emission of organic gases, heavy metals, and dioxins, furans and other organic pollutants generated by waste incineration will meet the specified emission standards.

The system can meet the following requirements: The system has a total of 2 sets of flue gas purification equipment, which is used for the purification of the tail gas of 2 waste incinerators and waste heat boilers, and removes organic gases such as acid gases and dioxins in the flue gas. And heavy metal pollutants, the flue gas through the system to achieve the required emission standards. The design of the flue gas purification system meets the requirements for the treatment of municipal waste incineration - waste heat boilers from start-up to design maximum operating conditions (exhaust gas volume requirements).

For more information, please pay attention to China's waste gas treatment equipment trading network:/


A ball check valve is a check valve in which the closing member, the movable part to block the flow, is a spherical ball. In some ball Check Valves, the ball is spring-loaded to help keep it shut. For those designs without a spring, reverse flow is required to move the ball toward the seat and create a seal. The interior surface of the main seats of ball check Valves are more or less conically-tapered to guide the ball into the seat and form a positive seal when stopping reverse flow.

Ball check valves are often very small, simple, and cheap. They are commonly used in liquid or gel minipump dispenser spigots, spray devices, some rubber bulbs for pumping air, etc., manual air pumps and some other pumps, and refillable dispensing syringes. Although the balls are most often made of metal, they can be made of other materials, or in some specialized cases out of artificial ruby. High pressure HPLC pumps and similar applications commonly use small inlet and outlet ball check valves with both balls and seats made of artificial ruby, for both hardness and chemical resistance. After prolonged use, such check valves can eventually wear out or the seat can develop a crack, requiring replacement. Therefore, such valves are made to be replaceable, sometimes placed in a small plastic body tightly-fitted inside a metal fitting which can withstand high pressure and which is screwed into the pump head.

There are similar check valves where the disc is not a ball, but some other shape, such as a poppet energized by a spring. Ball check valves should not be confused with Ball Valves, which is a different type of valve in which a ball acts as a controllable rotor to stop or direct flow.

A diaphragm check valve uses a flexing rubber diaphragm positioned to create a normally-closed valve. Pressure on the upstream side must be greater than the pressure on the downstream side by a certain amount, known as the pressure differential, for the check valve to open allowing flow. Once positive pressure stops, the diaphragm automatically flexes back to its original closed position.

A swing check valve or tilting disc check valve is check valve in which the disc, the movable part to block the flow, swings on a hinge or trunnion, either onto the seat to block reverse flow or off the seat to allow forward flow. The seat opening cross-section may be perpendicular to the centerline between the two ports or at an angle. Although swing check valves can come in various sizes, large check valves are often swing check valves. The flapper valve in a flush-toilet mechanism is an example of this type of valve. Tank pressure holding it closed is overcome by manual lift of the flapper. It then remains open until the tank drains and the flapper falls due to gravity. Another variation of this mechanism is the clapper valve, used in applications such firefighting and fire life safety systems. A hinged gate only remains open in the inflowing direction. The clapper valve often also has a spring that keeps the gate shut when there is no forward pressure. Another example is the backwater valve (for sanitary drainage system) that protects against flooding caused by return flow of sewage waters. Such risk occurs most often in sanitary drainage systems connected to combined sewerage systems and in rainwater drainage systems. It may be caused by intense rainfall, thaw or flood.

A stop-check valve is a check valve with override control to stop flow regardless of flow direction or pressure. In addition to closing in response to backflow or insufficient forward pressure (normal check-valve behavior), it can also be deliberately shut by an external mechanism, thereby preventing any flow regardless of forward pressure.

A lift-check valve is a check valve in which the disc, sometimes called a lift, can be lifted up off its seat by higher pressure of inlet or upstream fluid to allow flow to the outlet or downstream side. A guide keeps motion of the disc on a vertical line, so the valve can later reseat properly. When the pressure is no longer higher, gravity or higher downstream pressure will cause the disc to lower onto its seat, shutting the valve to stop reverse flow.

An in-line check valve is a check valve similar to the lift check valve. However, this valve generally has a spring that will 'lift' when there is pressure on the upstream side of the valve. The pressure needed on the upstream side of the valve to overcome the spring tension is called the 'cracking pressure'. When the pressure going through the valve goes below the cracking pressure, the spring will close the valve to prevent back-flow in the process.

A duckbill valve is a check valve in which flow proceeds through a soft tube that protrudes into the downstream side. Back-pressure collapses this tube, cutting off flow.

A pneumatic non-return valve.

Multiple check valves can be connected in series. For example, a double check valve is often used as a backflow prevention device to keep potentially contaminated water from siphoning back into municipal water supply lines. There are also double ball check valves in which there are two ball/seat combinations sequentially in the same body to ensure positive leak-tight shutoff when blocking reverse flow; and piston check valves, wafer check valves, and ball-and-cone check valves.

Check Valves

Check Valves, Water Check Valves, Brass Check Valves, Sanitary Check Valves

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