Common problems of bag filter in cement industry

1. Air volume of bag filter 

Due to the advancement of cement production technology and the transformation of cement production technology, the output of single-machine equipment is continuously increasing, and the emission of exhaust gas is also continuously increasing; when designing the process design, the design institute still selects the bag filter according to the original parameters, resulting in insufficient air handling capacity , Leading to the failure of the dust collector; many bag filter equipment manufacturers do not understand the process, are not familiar with the process, and cannot configure the dust collector according to the change of process conditions, which will also cause loss due to insufficient air flow.

2. Dust concentration of bag filter 

With the technological advancement of the cement industry process and the continuous adoption of new processes, the dust concentration in the exhaust gas discharged compared with the traditional process has changed greatly; such as the use of vertical mills, extruders and powder concentrators, the process is further simplified. The output is greatly increased, and the dust concentration in the exhaust gas is also greatly increased. In the raw meal and cement grinding process in the cement industry, the bag filter is not only a dust removal device, but a host device in the process. The inlet dust concentration reaches more than 1600g/Nm3. Generally, the first-level dust removal facilities are used. This process characteristic is not considered, which is also one of the reasons for the failure of the bag filter.

3. Filter material of filter bags 

The filter material is the heart of the bag filter; the selection of the filter material is a work with high technical content. It is necessary to have an in-depth understanding of the characteristics of the gas and dust to be processed, and the filter material required according to these characteristics; The physical and chemical characteristics of the material itself, try to make the filter material you choose to be used within its characteristics; many equipment manufacturers and owners often pay insufficient attention to them, but choose the filter material according to the price, and ignore the use conditions and products of the filter material the quality of.

4. The characteristics of dusty gas

　　 The treated dust has different characteristics due to different process conditions and use conditions; including dust concentration, temperature, humidity, exhaust gas volume, and the degree of fluctuation of these characteristics will affect the use of bag filter.

5. Clean design of filter bag

The dust removal of the bag filter is the key to the long-term reliable operation of the bag filter, so which method of dust removal is used in different occasions is very important; especially in the cement industry, different occasions have different characteristics of exhaust gas; In the raw meal processing process, the humidity problem should be considered; the high temperature problem should be considered in the firing process; the combustion explosion problem should be considered in the coal mill; the abrasion problem and high concentration problem should be considered in the production process; which method to choose under these conditions is very important .

6. Design of unloading ash

The ash unloading problem of bag dust collectors is often not taken seriously by designers and users, but this is one of the reasons why bag dust collectors in the cement industry are not used well; the design of ash hoppers, the selection of ash unloading valves, and the needs of ash hoppers The need for heating, whether to add shock and beat facilities, etc. are related to the long-term and reliable operation of the ash unloading process.

7. Design of control 

The control of the bag filter is comprehensively considered according to the conditions of use and the size of the air volume, including the control of main parameters such as ash cleaning, ash unloading, temperature, resistance, etc.; for large bag filters, parameter recording and alarm functions should also be considered For those with high requirements, fault diagnosis and display functions should be considered; this is not something that can be solved by a single-chip computer, single-board computer or PLC. It is necessary to design whether a DCS control system needs to be configured according to the conditions of use and the requirements of the owner.

8. The design of the bag filter equipment body

The production and design of the bag filter equipment body is very important, and many equipment manufacturers do not pay much attention to it; they often think that the threshold of the bag filter is very low, the production is relatively simple, and it can be manufactured and used as long as a drawing is obtained. ; The fact is not the case, the design of dust removal and unloading of the bag filter; the design of the high temperature bag filter equipment body includes thermal stress problems, high temperature expansion problems, high temperature corrosion problems; room temperature bag filter toner condensation and corrosion; coal grinding cloth bags The problem of dust accumulation, flame-proof and explosion-proof of the dust collector; the air distribution problem of the large bag filter. Maintenance issues, usage issues, etc. are all ontologies that need to be carefully considered. The bag filter should also be designed according to the process and use conditions to solve the manufacturing and use problems.