INVT GD5000 Series MVD applied to DD Washer in Indonesia

Release time：2024-12-05

Click amount： 277

Abstract: This article mainly introduced INVT GD5000 medium voltage drive applied to DD washer and described detailed information involving the structure, principle, process, feature of DD washer. The practical application shows good speed control performance and stability of INVT GD5000 3.3kV drives and it is worth promoting.

Keyword：INVT, GD5000 MVD, DD washer, Energy saving

1. Brief introduction

Pulp and paper making process

In the pulp and paper making process, the washing, screening, purification, bleaching, post bleaching washing and concentration processes have the highest energy, chemical consuption, and water and drainage volume. It is recommended to use the counterurrent washing process in this section to promote water conservation and emission reduction.

DD washer process

The Drum Displacer washer(DD washer) has designed in response to the demand for improved washing efficiency, reduced operating, maintenance and capital costs. Today the DD washer is widely accepted by pulp mills all over the world. The family of DD washers comprises machines that can be fed at low(from 3%to 6%,LCDD) or medium(from 8%to 11%, MCDD)consistency. The number of washing stages varies from one to four. Due to its unique segregated counter-current washing principle, a high washing efficiency can be reached. The design and the construction of the DD washer has been further developed, so that even higher displacement washing efficiency can be achieved and this excellent washing efficiency has been proven in the trial. The DD washer installation positions include brownstock washing, post-oxygen washing and bleach plant.

2. Project information and solution

2.1 DD washer information
Detailed motor parameters are list as follow：

Motor tag at site	Motor power(kW)	Motor voltage
BSW Feed MC Pump	630	3.3kV
BS DD Washer	355	3.3kV
O2 MC Pump 1	800	3.3kV
O2 Feed MC Pump 2	800	3.3kV
Pump to Wenuri WP	500	3.3kV
Post O2 Feed MC Pump	315	3.3kV
Post O2 Feed MC Pump	630	3.3kV
Unbleached Tower Feed MC Pump1	710	3.3kV
BSW Feed MC Pump	18.5	380V
BS DD Washer	18.5	380V
O2 Feed MC Pump 2	630	3.3kV
Pump to Wenuri WP	355	3.3kV
Post O2 DD Washer	800	3.3kV
Post O2 MC Pump	750	3.3kV
O2 Feed MC Pump1	355	3.3kV
Unbleached Tower Feed MC Pump1	630	3.3kV
Post O2 DD Circulate Filtrate Pump	900	3.3kV
BS DD Circulation Filtrate Pump	800	3.3kV
BS DD Circulation Filtrate Pump	18.5	380V
Post O2 DD Circulate Filtrate Pump	18.5	380V

Table 1.DD washer motor list

2.2 System solution.

According to customer demand and considering load condition and uniform spare parts, the below VFDs are selected for this project.

VFD Model	Power	Rated Voltage	Rated Current	Quantity
GD5000-A0800-3.3-S	630kW	3.3kV	140A	5
GD5000-A1250-3.3-S	1000kW	3.3kV	219A	10
GD5000-A1400-3.3-S	1120kW	3.3kV	245A	1
GD35 LVD panle	22kW	380V	45A	4

Table 2.VFDs for DD washer

Main system diagram:

Control sketch diagram

DD washer site photo

MVDs in the machine roon

MVD monitoring via Ethernet

3 Application and Advantage

After using VFD, there are some major advantages as follow:

* Energy saving, chemical saving: The pumps and washer are running at optimal situation and can save energy.

* Wide range speed adjusted: Because VFD is a step-less speed regulation, the pump and washer can be run smoothly with wide speed range. It means that the speed adjusted can be elaboration and sensitive.

* Increase grid line power factor: The grid line power factor is over 0.97. It can increase efficiency of the grid power.

* Perfect output waveform: Output waveform is perfect, less than 2% of distortion.

* Prolong motor working life time: VFD can keep motor running at optimal situation.

4. Conclusion

Compared with old technology, the MVD driven method has many advantages. Especially significant energy saving. After commissioning, all the MVDs work very well, meet the process demand, customers are satisfied with INVT solution.