Study On Preparation And Hydraulic Performance Of Microporous Concrete Irrigation Emitters

Seepage irrigation is a new type of irrigation technology,which can save water resources well.Due to the immature development of material manufacturing technology,seepage irrigation has been in the long-term exploration stage.Compared with organic plastic materials,microporous ceramics are typical inorganic nonmetallic materials,and their unique physical and chemical properties make the microporous ceramic irrigation emitters suitable for seepage irrigation.However,the preparation of microporous ceramic irrigation emitters requires sintering process,which increases the cost of the irrigation emitters and hinders the further development of seepage irrigation technology.Concrete and ceramics belong to inorganic non-metallic materials,both of which have very similar physical and chemical properties.Concrete seepage irrigation emitters with porous microstructure and good performance could be prepared by appropriate methods.This paper discusses the preparation methods of porous concrete irrigation emitters.Concrete seepage irrigation emitters with excellent comprehensive performance were obtained by analyzing the influence of the grain size of sand and content of cement on the performance of the concrete seepage irrigation emitters.Based on the above studies,the preparation and properties of the concrete seepage pipeline with function of water infiltration and transportation were studied,and the effect of integrated irrigation of water and fertilizer by using concrete seepage irrigation emitters was also studied.The results are as follows:?1?The change of seepage flow rate of microporous concrete irrigation emitters is closely related to the pore size and open porosity of microporous concrete irrigation emitters.The change of the grain size of sands and the content of cement leads to the change of pore size and open porosity of microporous concrete,and then leads to the change of seepage flow rate of microporous concrete irrigation emitters.In general,the change of cement content and grain size of sands effect the water seepage of microporous concrete emitters and strength of microporous concrete emitters,but the degree of effect is different.The microporous concrete irrigation emitters with cement content of 15%-18%has higher bending strength and seepage capacity at the same time.?2?The internal pressure increases with the increase of water supply pressure.As the distance between the measured position and the water inlet increases,the influence of the change of water supply pressure on the pressure of the infiltration pipeline becomes smaller and smaller.When the water supply pressure is constant,the amount of pressure loss along the front,middle and rear sections of the infiltration pipeline is different.Among them,the amount of pressure loss along the middle and rear sections of the infiltration pipeline is small,while the amount of pressure loss along the front section of the infiltration pipeline is large.When the water supply pressure is 0.045 MPa,porous concrete seepage water pipe frictional pressure loss in conformity with the linear function relationship of H=(0.045+?0.1?L?^4.6)?0)^-0.235).As the pressure loss curve along the infiltration pipeline when the water supply pressure is relatively small is a part of the pressure loss curve along the infiltration pipeline when the water supply pressure is relatively high,this formula could also be used to calculate the water pressure at different positions in the internal of the infiltration pipeline when the water supply pressure is lower than 0.045 MPa.?3?The microporous concrete irrigation emitters can be used for conventional irrigation of crops,the Ca²⁺,Mg²⁺,SO₄^2-and CO₃^2-in tap water do not affect the seepage flow rate of the microporous concrete irrigation emitters.When the microporous concrete irrigation emitters are used for fertigation,the fertilizer containing insoluble substances has a great influence on the seepage flow rate of the microporous concrete irrigation emitters.Therefore,in practical application,the chemical fertilizer containing insoluble substances should be configured into a solution for filtration before being added to the irrigation water,which can effectively avoid the blockage of the microporous concrete irrigation emitters during fertigation.