A slurry-water online switching method in a long-distance slurry pipeline transportation system

Abstract

The invention provides an on-line switching method for slurry and water in a long-distance slurry pipeline transportation system. The method comprises the following steps that first, the flow of main pumps is reduced to the minimum value, and meanwhile the rotating speed of a feeding pump is increased to a full rotating speed; second, a stirring tank outlet valve is closed step by step, a water valve is opened, closing is suspended when the stirring tank outlet valve is closed by a half or so, and the water valve is continued to be opened; third, after the water valve is completely opened, the stirring tank outlet valve is closed; fourth, after the stirring tank outlet valve is completely closed, the rotating speed of the feeding pump is reduced, and the flow of the feeding pump is made to be matched with the flow of the main pumps; fifth, the flow of the main pump is increased to the normal working flow. According to the on-line switching method for the slurry and water in the long-distance slurry pipeline transportation system, the relation between the distance from the water valve to a stirring tank and the distance from the water valve to the feeding pump is taken into full consideration, innovation is carried out on the opening and closing relation between the water valve and the stirring tank outlet valve, slurry and water switching is stably achieved, the phenomenon that main pumps may be shut down during slurry and water switching is completely avoided, and slurry and water switching efficiency and slurry pipeline transportation efficiency are improved.

Description

technical field [0001] The invention relates to the technical field of slurry pipeline transportation, in particular to an online slurry-water switching method in a long-distance slurry pipeline transportation system. Background technique [0002] Slurry pipeline transportation technology belongs to a new type of material transportation technology. Usually, mineral resources are crushed and mixed with liquid to form a slurry suitable for pipeline transportation, and then the slurry is transported by pipeline. The terminal is performing dehydration and other treatments on the slurry. This kind of slurry pipeline transportation has unique advantages such as low freight, large transportation volume, few failures, and low environmental pressure. The existing slurry pipeline transportation system involves multi-stage pumping station pressurization. During the transportation process, there is a continuous pumping mode and a disconnected transportation mode in which the pulp of ea...

AI Technical Summary

Problems solved by technology

Therefore, in the process of slurry pipeline transportation, frequent slurry-water switching is required. The slurry-water switching in the prior art is mainly based on two operation methods: the first operation method is to switch the slurry and water valves after shutting down the relevant operating equipment , restart the equipment after the switching is completed. This operation method is likely to cause equipment failure because it requires frequent shutdown operations, and it will cause difficulty in starting with pulp.

Stoppage should be avoided as far as possible during slurry transportation, so the second operation method is to directly open the water valve during the operation of the equipment, and then close the slurry outlet valve of the mixing tank to switch slurry transportation to water transportation. In practice, the operation method often causes the main pump to stop passively. Since the slurry in the mixing tank is basically emptied when the slurry water is switched, and the water valve is relatively close to the mixing tank, the moment the water valve is opened, The disparity in water pressure (process water 700kpa) will cause the water to flow directly into the mixing tank (the distance between the water valve and the mixing tank is short and the resistance along the way is small, and the distance between the water valve and the feeding pump is far away and the resistance along the way is large), resulting in the failure of the remote feeding pump. Insufficient suction material makes the feeding pump unable to provide stable flow and pressure to the main pump of the subsequent stage, which directly causes the main pump to shut down due to insufficient suction material and low pressure. If the primary pump station shuts down, the subsequent pump stations will also stop in chain. This abnormal shutdown often causes failure of the main pump and other equipment, and long-term shutdown will cause difficulty in starting with slurry

Therefore, there is no slurry-water switching method that can ensure the stable delivery of slurry in the prior art

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