FAQ

 


 

We have problems with extraction capacity on our filter. Can you help us with this?

Yes. Clogged filter fabric, i.e. that dust particles penetrate into the filter fabric so that the resitance of the fabric increases and gives a too low level of flow can have sveral causes. If it does not help to cleanse the filter cloth with the fan turned off one may have to change filter fabric (filter bags or filter cassettes). See PFDX for more information on this.

A too high cleansing frequency of the fitler cloth, i.e. a too short cleansing cycle increases the clogging of the filter cloth since each cleansing removes the filtering dust overlay, which effectively prevents the finest dsut fractions from penetrating into the filter cloth. Resistance controlled cleansing optimizes the cleansing and increases the life length of the filter cloth. Please see CPFA for more information!

The ducting system may also be clogged. When the filter plant is run with too low capacaity the velocity in the ducts gets so low that the dust falls out in the duct. In that case one must cleanse the ducts from dust. See our sections for the appropriate equipment!

A worn-out fan can also cause a too low transport capacity. Repair the fan by for instance switching the fan wheel so that the capacity is restored.

A change in the production process can change the character of the dsut particles by creating a finer partition of the dust particles. The resistance of the dust then gets higher and creates a need for a higher fan capacity or possibly even an adaption fo the filter to the changed process. Please take a look at our production sections for possible upgrades!

 

Can you offer manuals/assistance in more languages than English and Swedish?

Yes, if agreed upon in the contract we will supply you with operation manuals in the requested language. In general, assistance in German and Russian, is apart from Swedish and English no problem.

 

We have a different brand than yours. Can you supply us with spare parts anyway?

Yes, we have knowledge about most of the existing brands and can hence without problems find suitable parts to your plant. Please contact our responsible for spare parts sales.

 

We need help with air flow calculations of different kinds. Can you help us?

We gladly help you with our expertise when it comes to calculations/consultation regarding different airtechnology calculations and investigations for filter plants.

 

We have too emissions from our filter. Can you help us with the causes of this?

Yes, we can solve all problems which cause too high emissions, please contact our service responsible.

 

We now face stricter emission restrictions on our filter. What can we do?

Yes of course! We can construct upgrades of filter plants of most brands and improve the separation degree as well as, in some cases, the capacity.

 

The life length bag filters/cassettes is very short. Can it be improved?

There are several reasons to worn-out filter hoses or cassettes. To find out the correct cause one must investigate where the damage occured. If it is on the dust side of the bag filter/hose/cassette, i.e. primary wear (A) or on the "clean" side, which we usually call secondary wear damages (B):

A) In the first case, with primary wear, it can possibly be the construction of the filter unit, which does not slow down the gas and the transportation velocity of the dust particles sufficiently. This means that wearing dust particles blast or tear the filter cloth down. Since the flow in a filter chamber is turbulent these blasting damages may occur on large areas in the filter chamber.

B)In the second case with secondary wear, which often occurs belows the outflow of the filter element, the cause can be that the separation ability of the filter media is too bad. The dust particles which accompany the clean gas out from the filter element are blown back by the cleaning pulse, which blasts apart the filter cloth from the inside. The same type of wear damage also occurs if the filter elements upstream have wear holes caused the same manner as the one already mentioned in A above.

This type of damage also occurs if the filter cloth has over cleansed, i.e. if the cleansing frequency is too high, the cycle time too short, so that the filter cloth is working without the so important "filter layer" which consists of the dust layer.

 

We have very high energy consumption on our filter. Which measures can be taken to decrease it?

Many filter plants have badly optimized settings for the filter cleansing. If the filter cleansing has pressure drop control it is not unusual that too much cleansing is done, i.e. the setpoint for pressure drops so low that it corresponds to a resistance (permeability) which is lower than the real one. thus means that the filter cleansing will work constantly.

Solution 1 - raise the setpoint so that there are pauses in the filter cleansing.

Solution 2 - set the pause time so that the shortest cycle time becomes about 15 minutes.

Solution 3 - change the control method for cleansing so that it is controlled through the sm-method. Please see the section CPFA. This method can also lower the energy consumption for the main fan since it allows the pressure drop to vary with the cyclic flow the process gives. See the section about resistance based steering and control.