Ash removal equipment
The ash removal equipment refers to the equipment for discharging ash from the boiler body from the outlet of the waste ash boiler. Due to the different process characteristics of various industrial furnaces, the requirements for ash removal are also different. The following points should generally be considered:
(1) Ash residue falling into a cold ash hopper generally has a recovery value. The recycling of ash should be considered.
(2) If the flue gas entering the waste heat boiler contains more sulfur dioxide and sulfur trioxide, the flue gas is used for acid production. Ash removal equipment must be considered for corrosion protection and sealing.
(3) The density of ash residue is relatively high, the temperature is high or the hardness of the slag block is high after coking, and the ash removal equipment should have good high temperature resistance and wear resistance.
(4) The cold ash bucket of the waste heat boiler is opened along the length of the boiler, and the structure of the ash removing equipment is required to match. At the same time, it is necessary to consider the removal of large slag.
In order to meet the above requirements, waste heat boilers usually use horizontally arranged mechanical ash removal equipment. Commonly used are scraper ash remover, frame chain ash remover, buried scraper conveyor and screw conveyor. Such conveyors can refer to the selection manuals and samples of the equipment, and check the ash residue according to the density, temperature sequence, and tongs, and make necessary modifications.
Cleaning equipment
The dust cleaning facility of the waste heat boiler is an important part to ensure the normal and safe operation of the waste heat boiler. Commonly used methods of cleaning are soot blowing and rapping.
(1) Soot blowing
Soot blowing is mainly done by a soot blower. The soot blower is a kind of cleaning device that uses the dynamic pressure head sprayed by the soot blowing medium to clean the dust adhering to the heated surface.
The selection of the soot blowing medium is determined based on the characteristics of the flue gas, whether the exhaust gas is acid, the source of the medium, and the specific working conditions of the waste heat boiler. Alternative blowing materials are steam, compressed air, compressed nitrogen and water. The medium pressure is generally (9.807~15.691) X 105Pa, and the effective radius of soot blowing is 1.5~2.5m. Steam soot is mostly used in flue gas with a flue gas temperature above 500 °C.
The types of soot blowers are long telescopic, short telescopic, fixed and coal-saving soot blowers. Can be selected according to the requirements of soot blowing and the temperature of use.
(2) rapping
The vibrating cleaning is performed by the action of the rapping device or the vibrator, periodically vibrating the heating surface of the boiler, and the bonded soot is cracked and gradually enlarged under the action of instantaneous impact force and repeated stress, and simultaneously makes the dust The adhesion to the heated surface is destroyed and the bonded soot is shaken off.
Rapping and cleaning has many advantages in terms of investment, power consumption, and cleaning effect. Therefore it is widely used. Most of today’s waste heat boilers use full vibration to clean.
The commonly used rapping and cleaning equipment has a hammer-type vibrating cleaning device and a vibrator.
