Automation of the grain dryer at Vidrodzhennia LLC

Primary goal:

Equipment for control and automation of grain dryer DSP-32.

Scope of work:

• Development of design documentation for an automatic control system.
• Complete set of controls.
• Manufacturing of power and control cabinets.
• Development of algorithmic support.
• Software development.
• Installation of automation equipment.
• Commissioning works.

Technical means:

• Power supply and control cabinet.
• Programmable controller Simatic S7-315.
• Industrial PC with touch screen.

All electrical switching equipment is housed in cabinets made of 1.5 mm thick steel coated with a polymer powder coating with preliminary phosphating. The boards are certified according to the international standard ISO 9001:2000 PRA 000 3966 dated December 1, 2005. The degree of protection of the cabinets is IP55. Power distribution circuits made on the basis of electric power fittings by Lovato have established themselves as reliable and trouble-free equipment.

In control cabinets and push-button stations installed at the equipment site, controls (buttons, switches) in the IP65 version are used. On the front panel of the power supply and control cabinet there are controls and controls for equipment: operating mode switches M-O-A, control buttons Start, Stop.

The automation system was built on the basis of a programmable controller SIMATIC 315-2 PN/DP (SIEMENS), equipped with built-in Profibus and USO interfaces consisting of:

• Digital signal input module 32 channels 24V – 1 unit.
• Digital signal output module 32 channels 24V – 1 unit.
• Analog signal input module 8 channels – 2 units.

SDAU grain dryer DSP-32 is designed to control the technological process of drying with transport mechanisms that provide supply and removal of the product.

The system has two operating modes selected on the control panel:

• Local mode.
• Auto mode.

In local control mode, the operator can control the units from push-button stations located in close proximity to the unit itself. As a rule, this is necessary for debugging work, as well as in cases where visual control of the mechanism’s operation is necessary. The mechanisms can also be launched from the switchboard, where the control buttons for all equipment are located.

In automatic control mode, the selected route of operation of transport mechanisms is launched according to the algorithm described in the PLC program. Namely:

Automatic start of fans of drying zones in a certain sequence with control of the presence of product in the drying shafts, control of the operating time required to start safe operation of the burner.

Permission to fire up the burner after the end of the pre-ventilation mode and the readiness of the mechanisms.

Automatic start of the route of transport mechanisms supplies and removes the product in sequence, which prevents product jams with full control of the state of the mechanisms and their operating modes.

Control of gate valves and tilting valves depending on the chosen route with monitoring the condition of mechanisms and levels in bunkers.

Control of the operation of exhaust devices.

Control of limit levels in the feed hopper.

Adjusting the product level in the ultra-drying hopper.

Optimization of the temperature of drying agents in zones 1 and 2.

Control of boundary temperatures of drying agents and grain temperature in zones 1A, 1B, 2A, 2B.

Providing an emergency sound and light alarm in the following cases:

• Unauthorized shutdown of fans.
• Collapse of the route of transport devices.
• Overheating of grain.
• Reaching limit levels.
• Burner accidents.
• Reaching the maximum grain temperatures.

The operation and status of the mechanisms and the dryer itself, the temperature of the drying agents and grain in all zones are displayed on the touch panel screen. Optimization of temperatures of drying agents in zones 1 and 2 is carried out according to several parameters:

• Temperature of drying agents.
• Grain temperature in drying zones.
• Humidity of grain at the entrance to the dryer.
• Humidity of grain at the exit from the dryer.

Humidity measurement is carried out using a humidity and temperature sensor "Variant - MS" manufactured by the "Variant" corporation, Dnepropetrovsk. The regime map for each grain crop is stored in the controller’s memory and, if necessary, can be used in the drying workflow. The system keeps logs of the operating modes of the mechanisms and dryer, and also maintains an archive of all process temperatures for a certain period. If necessary, the operation of the dryer and transport mechanisms can be controlled via a remote computer.

Result:

Thanks to the implementation of this project, a modern drying complex was built, optimal modes were provided for bringing the product to the required storage parameters, fire-safe drying of grain with minimized energy costs and minimal human intervention.

Photo preview taken from the Sunolta website.

Customer comment

Timeframe for project implementation:

October 2009.