Correct choice of filtration material

Pro­tect­ing nat­ur­al resources and the air from harm­ful emis­sions of indus­tri­al enter­pris­es con­fronts indus­tri­al enter­pris­es with new, often dif­fi­cult tasks, to ful­fill the envi­ron­men­tal requirements.One of the effec­tive meth­ods for dust (gas) removal is to use of bag filters.The “Bag Fil­ter Fac­to­ry” LTD has more than 20 years of expe­ri­ence in the man­u­fac­ture of vari­able fil­ter ele­ments, “fil­ter bags” and fil­ter­ing units such as “Bag House”. Regard­less of who the man­u­fac­tur­er of the mate­r­i­al is, the respon­si­bil­i­ty for the qual­i­ty of fil­ter bag lays with the “Bag Fil­ter Fac­to­ry” LTD.

How to deter­mine which fil­ter mate­r­i­al the cus­tomer needs? When choos­ing a fil­ter cloth, many dif­fer­ent para­me­ters are tak­en into account, the fol­low­ing para­me­ters have the most sig­nif­i­cant effect:

• Tem­per­a­ture
• Humid­i­ty
• Chem­i­cal com­po­si­tion of the environment
• Com­po­si­tion, size and shape of particles
• Sta­t­ic electricity
• Type of fil­ter installation
• Require­ments for fil­ter­ing efficiency

Tem­per­a­ture is one of the main fac­tors when choos­ing a fil­ter cloth. At least it offers a start­ing point elim­i­nat­ing all mate­ri­als with a low­er oper­at­ing tem­per­a­ture. Humid­i­ty is also an impor­tant para­me­ter, because some poly­mers are prone to hydrol­y­sis, that can lead to the destruc­tion of the fil­ter cloth fibers, espe­cial­ly at ele­vat­ed tem­per­a­tures. The chem­i­cal com­po­si­tion of the envi­ron­ment can neg­a­tive­ly affect the fibers as aggres­sive sub­stances can cause their pre­ma­ture destruc­tion. For this rea­son, spe­cial atten­tion needs to be payed to poten­tial haz­ards such as: acids, alka­lis, hydrol­y­sis, oxi­da­tion and sol­vents. The com­po­si­tion, size and shape of the par­ti­cles pro­vides answers to the fol­low­ing questions:

• What is the abra­sive­ness of the dust?
• Does the dust stick?
• How fast does the dust move?
• Is the dust greasy, and maybe wet?
• Is there a sta­t­ic charge?

The type of fil­ter unit (Bag House), its design and the method of fil­ter bag regen­er­a­tion deter­mine the weight of the cloth. The giv­en para­me­ters should be con­sid­ered as a whole to eval­u­ate their influ­ence on each oth­er and, most impor­tant­ly, how they affect the main demand con­cern­ing the fil­ter mate­r­i­al — the effi­cien­cy of the fil­tra­tion. Today, there are sev­er­al types of high-tem­per­a­ture fil­tra­tion mate­ri­als and we would like to draw your atten­tion on one of them, a promis­ing high-tem­per­a­ture mate­r­i­al: fiber glass. Fiber glass fil­ter fab­rics allows for high purifi­ca­tion val­ues at the out­let of the Bag House at oper­at­ing tem­per­a­tures of 260–280°C in chem­i­cal­ly aggres­sive envi­ron­ments, which great­ly extends the appli­ca­tion range of fil­ter bags.

Fil­tra­tion of gas­es and prod­uct cap­ture at tem­per­a­tures of 100 to 280°C is com­mon in var­i­ous indus­tries: coal boil­ers, met­al­lur­gi­cal plants, reac­tors for pro­duc­tion plants, car­bon black, non-fer­rous met­al­lur­gy, cement plants, and oth­ers. Con­trary to fiber glass fil­ter fab­rics, nat­ur­al and most syn­thet­ic fibers are destroyed in this tem­per­a­ture range

Fea­tures of fiber glass fabrics:

• The oper­at­ing tem­per­a­ture is 260–280 ° C, which is the max­i­mum for fil­ter materials
• Appli­ca­tion in fil­ter bags, both in back­flow and in fil­ters with pulse jet regeneration
• To improve the oper­a­tional prop­er­ties, fiber­glass fab­rics are treat­ed with spe­cial coatings

Such pro­cess­ing improves the tech­ni­cal char­ac­ter­is­tics of fiber­glass fabrics:

• • chem­i­cal resistance
  • pro­tec­tion of fil­ter bag from abra­sive dust
  • reduc­tion of inter­nal fric­tion between fibers
  • pro­vid­ing resis­tance to fibers

For the fil­tra­tion of fine dust par­ti­cles, the fiber­glass addi­tion­al­ly receives a PTFE mem­brane made of poly­te­tra­flu­o­roeth­yl­ene. In this case, the fiber glass achieves the fol­low­ing advantages:

• fil­tra­tion of fine­ly divid­ed dust
• improved regen­er­a­tion of bags
• the resid­ual dust is clos­est to zero

The preser­va­tion of prop­er­ties at oper­at­ing tem­per­a­tures from 100 to 280°C, a high degree of fil­tra­tion and purifi­ca­tion dur­ing regen­er­a­tion, high break­through load indices, chem­i­cal resis­tance and the pric­ing are the biggest advan­tages of fiber­glass fab­rics, mak­ing them unique when used in high-tem­per­a­ture fil­ter bags.