Our elaborations

   Dozer “Doza”

The dozer is used for constant weighing dozing of dry substances in the technological workflows in different branches of industries. The dozer can be used both as a stand-alone device and as a part of complex dozing systems.

 The dozer structure

Dozer is a system consisting of weight transporter, electrical drive, control system. It operates on the base of constant measuring of the substance consumed principal.

The structure scheme of weighing transported dozer.

 Operational principal

The weight meaning from force measuring tension metric sensor and band speed come to the control system. The control system makes calculations of factual mass consuming meaning and compares it with the set point. Regulation, i.e. keeping the set consuming point, is carried out on account of band speed changing.

Substance supply onto the band is produced by means of supplier through the bending die. The supplier type (vibratory, auger, rotary, etc.) depends upon the character of the substance dozed. To control the supplier and even load of the dozer in the system the sensors of emptying and overfilling in the bending die are provided (level sensors).

 Specifications:

 The control system based on the controller SIMATIC C7-633 SIEMENS

The control system processing the signals coming from the sensors located on the weight transporter or a supplier:
- weight on the band signal from  force measuring tension metric sensor ;
-band speed from drive shaft and driven shaft sensors;
- signals from band descending (right or left) sensors;
- signal from band promptness sensor;
- supplier  sensor signal;
- min and max substance in the bending die signal.
The control system is based on programmed controller SIMATIC С7-633 SIEMENS, connected to the operator’s board. It has 16 built-in discrete inputs, 16 discrete outputs, 4 analog inputs and outputs and also 4 multi purpose discrete inputs.

Technological workflow data display and input of variables is carried out by means of Russian version operation panel with liquid-crystal indicator 4х20 characters. Protection rate of the right side - IP65. The accidental messages, technological workflow data and prompts are on the indicator. To access the elements settings you can use the password. The system automatically stores the data for the last 30 days and archives the accident massages. This gives you the possibility to monitor the dozer work history.
To control electric drive of the transporter is carried out by means of frequency converter MICROMASTER 440 SIEMENS, which provides high electric drive control accuracy with built-in microprocessor control system. The system has converter and motor overload defense.

Drum barreling motor-drum RULMECA is applied as an electric drive in the weight conveyor. The drive is built into the vacant inner drum space and thus it is completely closed. The construction is waterproof and has protection rate IP 67.
The built-in reducer influences the drum. Due to this process coefficient of efficiency is up to 97 % and absolute band centering is provided.
The weight transporter has the post of local control to switch modes and provide an emergency stop.

The dozer control system provides:
Input signals processing and control action making on the transporters and the supplier electric drive;
Transporter band speed measuring taking into account slipping motion;
Keeping specified productivity;
Substance mass computing in a time interval;
Computing and recording statistic parameters (operation and idle stand time)
Calibration
Supplier productivity and weight transporter clocking
Band position control
Commands input from the keyboard on the right side cubicle panel
Dozing parameters indicator
Emergency control and signaling
Data output at the upper level of the automated control system

 Control modes
Automatic – dozing with the controller operation. All the interlocks perform and controlling algorithm;
Local – calibration and setting operations and mechanical setup. Controlling algorithm and interlocks do not perform.
The modes switching is performed from the local operation place or from the operation panel on the cubicle or by the operator from the upper level of the automated control system.

 System peculiarities
The control system is performed on the SIEMENS equipment for all industrial use. The operation of such a system is much easier in comparison with other systems based on the parts from different producers or just having different unique designs.
The advantage is that the programmed controller is applied in the control system. Reconfiguration, adding new outer connections, algorithms approving can cause only the necessity of reprogramming the controller. The program with the all the detailed information is enclosed and is considered to be a part of the device that is given to the Consumer.
This control system can be connected to the upper level of the automated control system by the following ways:
- The controller has C7-633 built - in MPI interface that can transfer the information on the protocol MPI;
- if you want you can add an additional interface module to connect to the net  Profibus or Industrial Ethernet;
- or you can also make the communication on the freely programmed protocol on any of the interfaces: RS-232; RS-485; RS-422; TTY.
The control system is delivered as a cubicle 1200х600х300mm. The cubicle RITTAL (Germany) provides microprocessor protection rate IP65.

On the right side of the cubicle there is an operation panel with the liquid crystal display and functional keys and supplier indicator.
If you are interested in the dozing system you can please, complete in a form. We will get the business proposal and send it to you.

We will be glad to carry out your order!