February 17, 2022

Dry fog and dust suppression spray system scheme in coal loading and unloading

Coal loading and unloading dust production points:

1) Dock belt conveyor belt head. The material falls into the downstream chute along the belt. Due to the release of the potential energy of the falling material, the material rebounds after the side wall of the chute, and continuously collides with the material that falls later, generating dust. The dust is extruded along the chute as the material falls. Fly upwards.
2) The belt receiving point of the cantilever belt conveyor. The material falls into the downstream chute along the belt, and the material in the chute falls to the cantilever belt conveyor. Due to the release of the potential energy of the falling material, the material rebounds on the belt, and collides with the subsequent falling material continuously, producing dust. The air extruded by the dust with the falling of the material scatters around along the gap of the material guide trough.
3) Cantilever belt conveyor belt head. The material falls into the downstream chute along the belt, and the potential energy of the falling material is released, causing the material to rebound on the chute wall, and collide with the subsequent falling material continuously, resulting in dust, and the dust extruded along with the material falls along the air. The slipper scatters toward last week.
4) Throwing shovel at the head of the cantilever belt conveyor. The material falls into the downstream throwing shovel along the chute. Due to the release of the potential energy of the falling material, the material rebounds after the plane of the throwing spoon, collides with the subsequent falling material continuously, and scatters irregularly (unorganized) around. At the same time, after falling into the cabin, the falling materials collide with each other and scatter randomly (unorganized) around.

dust control nozzle

Composition and function of dry fog and dust suppression system

The dry fog dust suppression system adopts modular design technology, which consists of micron-level dry fog machine, screw air compressor, air storage tank, sprayer assembly (spray box or universal joint sprayer assembly), water and gas connection pipeline, electric partner It consists of thermal system and automatic control system.
1) The micron-level dry fog dust suppressor is to filter the air and water, control the solenoid valve to open or close according to the set air pressure, water pressure, air flow and water flow according to the switch program, and transport it to the sprayer assembly through the pipeline. , to achieve spray dust suppression. It consists of electronic control system, multi-function control system and flow control system. Installed in an IP 55 standard box, there are 1 air inlet pipe interface, 1 water inlet pipe interface, 1 air outlet pipe interface, and 1 water outlet pipe interface. The panel has a text display, gas and water pressure gauges and buttons for the electronic control system.
2) The electronic control system is the control center of the dry fog and dust suppression system, which integrates programmable controllers, protection circuits, relays and related components. The system has two modes of operation, automatic and manual. In automatic operation mode, it can automatically receive a remote trigger signal to start or stop the sprayer. In manual mode, the operator can manually start or stop the sprayer spray. You can also modify the spray cycle and pipeline purge time through the PLC setting interface.
3) The automatic control system connects the dry fog dust suppressor with the control signals of the field equipment to realize automatic control.
4) The spray box/universal joint sprayer assembly receives the air and water delivered by the dry fog dust suppressor, and converts it into dry mist with a diameter of 1-10 microns, which is sprayed out according to the dry fog dust suppressor. The control command is sprayed to the dust suppression point. When the dry fog and the dust particles contact and collide with each other, the dust particles are bound to each other, agglomerate and become larger, and settle under the action of their own gravity, so as to achieve the effect of dust suppression.
5) The screw air compressor (with capacity regulating valve) is the standard air source for the dry fog dust suppression system.
6) The water and gas connection pipeline connects the dry fog dust suppressor, spray box sprayer assembly, screw air compressor, compressed air storage tank, water source, etc. with stainless steel pipes of different pipe diameters as required.
7) The multi-function system is to filter the suspended matter in the water from the external water source to the standard required by the sprayer assembly, adjust the pressure and flow of air and water, and distribute them to each sprayer assembly through the distributor and valve. . It integrates all filters, solenoid control valves, water and gas pressure regulators, line purge valves and pressure sensors. All components, from the pipe at the upstream water supply of the system to the terminal sprayer, are made of hot-dip galvanized pipe, copper, nylon and other corrosion-resistant materials.
8) Electric heat tracing and thermal insulation systems are distributed on the dry fog dust suppressor, sprayer assembly and water and gas pipelines, and start when the ambient temperature is lower than +5°C.

Targeted design

1 Dock belt conveyor belt head
Design and configuration 1 set of water and gas distributor, 6 sets of universal joint sprayer assembly. The spray time is continuous, and a set of material flow sensors are designed and installed.
2 Cantilever belt conveyor belt receiving point
Design and install 1 set of water and gas distributor and 10 sets of universal joint sprayer assembly. Among them, 4 sets of universal joint sprayer assemblies are designed and installed at the upstream belt of this material receiving point; 6 sets of universal joint sprayer assemblies are designed and installed at the downstream belt of this material receiving point. The spray time is continuous.
3 Cantilever belt conveyor belt head
Design and configuration 1 set of water and gas distributor, 6 sets of universal joint sprayer assembly. The spray time is continuous.
4 Cantilever belt conveyor head chute throwing shovel
Design and configure 1 set of water and gas controller and 4 sets of spray boxes: one set of spray boxes is designed and installed directly above the discharge opening of the throwing shovel, and one set of spray boxes is designed to be installed on both sides and the rear of the throwing shovel, all of which are installed with the throwing material. The spoon moves, and the spray direction is consistent with the falling direction of the material. The spray time is continuous.
The spray tank assembly at the head of the cantilever belt conveyor is connected to the system through high-pressure hoses and water, gas and cable reels, and water and gas are provided with thermal insulation measures.

Apply effects

1) After the dry fog dust suppression device is put into operation, the dust suppression rate reaches more than 90%, which reduces the amount of coal loss.
2) The original water spraying device has a large water spraying amount, which causes the water content of the raw coal to be too high. After using the dry mist dust suppression device, the water spraying amount is reduced by more than 90%, and the calorific value loss of the coal is reduced at the same time.
3) The dry fog and dust suppression device is equipped with electric heating cables in each functional system and all water and gas pipelines, and is designed to keep warm and antifreeze, which can ensure normal use in winter. After the dry fog dust suppression device is put into operation, the coal will not freeze in winter, the water consumption of the dry fog dust suppression system is small, the weight ratio of the material humidity increase is less than 0.02% ~ 0.05%, the belt will not slip or deviate, and it can be conveyed normally.
4) The operation of the dry fog and dust suppression device can realize fully automatic control mode. In the automatic operation mode, the spray operation is automatically controlled by the programmable logic controller (PLC) of the dry fog and dust suppression device according to the site conditions, which can realize unmanned operation. , reduce the labor intensity of on-site operators.

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