Corrosion-resistant chemical centrifugal pumps are characterized by high temperature resistance, acid and alkali resistance, and corrosion resistance. The basis for selection of corrosion-resistant chemical centrifugal pumps should be considered according to several aspects such as process flow and water supply and drainage requirements, including liquid delivery volume and equipment Head, liquid properties, piping layout, operating conditions, etc.
1. Flow rate is one of the important performance data of pump selection, it is directly related to the production capacity and conveying capacity of the entire device. For example, in the process design of the design institute, the normal, minimum and maximum flow rates of the pump can be calculated. When selecting the pump, take the maximum flow rate as the basis and take into account the normal flow rate. When there is no maximum flow rate, usually 1.1 times the normal flow rate can be taken as the maximum flow rate.
2. The head required by the installation system is another important performance data for pump selection. Generally, the head should be selected after magnifying 5%-10% of the margin.
3. Liquid properties, including the name of the liquid medium, physical properties, chemical properties and other properties. The physical properties include temperature c, density d, viscosity u, solid particle diameter and gas content in the medium, etc. This relates to the lift of the system, the effective gas Calculation of surplus and suitable pump type: chemical properties, mainly refer to the chemical corrosiveness and toxicity of the liquid medium, which is an important basis for the selection of pump materials and the selection of which type of shaft seal.
4. The piping layout conditions of the device system refer to the liquid delivery height, the liquid delivery distance and the liquid delivery direction, the lowest liquid level on the suction side, the highest liquid level on the discharge side, etc. Some data and piping specifications and their length, materials, pipe fitting specifications, and quantity And so on, in order to carry out the combing head calculation and cavitation allowance check.
5. There are many operating conditions, such as liquid operation T saturated steam power P, suction side pressure PS (absolute), discharge side container pressure PZ, altitude, ambient temperature, whether the operation is intermittent or continuous, and the pump position is fixed The ones are still removable.
Selection principle of corrosion-resistant chemical centrifugal pump
1. Make the type and performance of the selected pump meet the requirements of process parameters such as device flow, head, pressure, temperature, cavitation margin, and suction.
2. Must meet the requirements of media characteristics.
For pumps that transport flammable, explosive, toxic, or precious media, reliable shaft seals or leak-free pumps are required; for pumps that transport corrosive media, the convection parts are required to use corrosion-resistant materials. For pumps that transport solid particles, the convection parts are required to be made of wear-resistant materials, and the shaft seal should be flushed with clean liquid when necessary.
3. High mechanical reliability, low noise and low vibration.
4. Economically, the total cost of equipment costs, operating costs, maintenance costs and management costs should be taken into account as the lowest.
5. The centrifugal pump has the characteristics of high speed, small size, light weight, high efficiency, large flow, simple structure, no pulsation of infusion, stable performance, easy operation and convenient maintenance.
Precautions for the selection of corrosion-resistant chemical centrifugal pumps
1. It is necessary to understand the characteristics of the medium, its corrosiveness, temperature, viscosity, fluidity, density, particle content, etc. Knowing these parameters can ensure the accuracy of the selection and ensure that the corrosion-resistant centrifugal pump is not Corroded.
2. It is necessary to understand the parameters and conditions of the working conditions, understand how the pump is used, where it is used, where to deliver the medium to where, how much pressure, suction, flow, and the impact of flow changes on the working conditions , Cavitation performance, etc. Only by understanding these parameters can the pump model be selected more accurately.
3. Understand the application of changes in production capacity to the pump in the future. Many people only consider the current situation without considering future changes in production capacity and whether the pump is suitable. These need to be considered.
4. Consider the energy-saving properties of pumps. When selecting models, refer to the efficiency of pump manufacturers. Many people only consider whether the pumps are cheap. In fact, the cost of purchasing pumps in chemical plants accounts for only 1/5 of the cost, and most of them It is the cost of overhaul and electric energy.
5. Convenience of maintenance and general performance of accessories: Many chemical enterprise users were greedy for cheap when selecting and purchasing corrosion-resistant centrifugal pumps. They often chose the lowest-priced corrosion-resistant pump manufacturer. You must know that cheap is not good. It does exist. The cost of the pump is reflected in: design, trial production, molds, materials, labor, and craftsmanship, not just materials and labor. If a manufacturer's price for corrosion-resistant pumps is quite low, then you can only say, This manufacturer only has material and labor costs when producing pumps. No other costs have been incurred. One can imagine the quality of the pump.
