How to correctly solve the problems of the weighing seysterm

Submitted by Anne,09/10/2014
The weighing system in the mixing plant mainly consists of the aggregate weighing system,  cement weighing system, water weighing, cement fly ash and admixture weighing (according to the demand of the weighing). The weighing accuracy of weighing system is directly related to whether the concrete produced by the concrete mixing plant has reached the standard. How to correctly solve the problems of positive and negative pressure of the cement weighing system in mixing plant? Here are some solving ways provided by the Pioneer machinery.
The detail negative pressure solutions of cement weighing hopper: after the technical analysis and field test, the most fundamental reasons for these problems are: the two closed space without the air source of the mixing engine and weighing copper, when the exhaust fan works, the internal air can only be one-way out, resulting in negative pressure. If the exhausts fan with a smaller, because the force is too small, it doesn't have enough force to take the air with dust of the mixing engine and weighing copper. To add a supplementary inlet can solve the above problem. When the draught fan works, clean air enters from the air supply hole, dust air of the weighing hopper was inhaled by fan into the dust chamber after filtering, at this time , the air convection is formed, it will not produce the negative pressure.
The specific operation as follows: a 250 mm diameter hole is on the flat plate of the weighing bucket, a connecting flange is welded with a diameter of 250 x 80 mm short pipe, and then connected with a flange diameter of 250 x 520 mm small skeleton bag with bolts, it is  convenient to disassemble and clean. The detail size should depend on the field conditions. The material of the filter bag should choose those dust clothes with good air permeability, easy cleaning, and long service life. In addition, it should to be regular cleaned. Also can adapt another method, through a 150 mm diameter tube will host directly communicated with the weighing hopper and concrete mixing machine, the dusty air in the weighing bucket firstly enters the main engine, then the draught pipe of the main engine leads to the dust hopper precipitator side flange. Prolong its working distance by people, and this will  reduce  the effect of induced draft fan caused by the weighing hopper.
The positive pressure  problems produced by the weighing hopper : in the same way,the compensating hole should be installed on the main engine. A 200 mm diameter hole on the main engine, welding a flange diameter of 200 x 80 mm short pipe, connected a diameter of 200 x 400 mm with elbow pipe, head hoop for fixing a cloth sleeve. In plane intake installation, the position is farther away from the dusty air discharge ports, participate in the circulation of internal space is larger, in this case, the dust removal effect of the cement weighing equipment is better.