76results about How to "Reduce circulation loss" patented technology

A method is disclosed for reducing lost circulation in drilling wells, employing composite materials as lost circulation materials. The composites comprise a thermoplastic polymer and cellulosic fibers. Optionally the composites may include other components such as calcium carbonate, clay, oil and other blending agents.

A method for reducing lost circulation in drilling wells employs composite materials containing an engineering thermoplastic polymer and mineral fibers. Optionally the composites may also include other components such as calcium carbonate and blending agents.

An adequate operation and performance of a refrigerant system includes the steps of adding a refrigerant that is different from the original refrigerant, into the refrigerant system should any operational problems be observed during operation of the refrigerant system. As an example, should the refrigerant system be cycling frequently, a lower pressure refrigerant may be added or replace, partially or fully, the refrigerant the system being initially charged with. By making this change, the present invention can, for example, lower the provided system capacity, and hence reduce the amount of cycling. Additionally, conditioned space comfort and system reliability would be improved. Further, changes over time, such as the degradation of the heat exchanger performance, and their negative effect on system operation can be alleviated by such a refrigerant substitution.

The invention relates to a continuous production method for separating an acetic acid from water by azeotropic distillation, which mainly solves the problems of a solvent dehydration tower in the prior art, such as limitations to control methods, incapability of realizing automatic control when a feeding flow is significantly changed, and a large amount of entrainer circulation loss produced withthe change of a feeding load. In the method, uniform cascade control is performed on the liquid level of the feeding flow, passing through an acetic acid intermediate tank, of a rectifying tower; when the feeding flow of the rectifying tower is larger than the lower limit of the elastic operating range of the tower, feeding flow forward control is performed on the refluxing of water and oil phases at the top of the tower; and when the feeding flow reaches or is smaller than the lower limit of the elastic operating range, constant-flow control is performed on the refluxing of the oil phase at the top of the tower, and feeding flow proportional control is performed on the refluxing of the water phase. In the technical scheme, the problems are better solved; and the continuous production method can be applied to the industrial production of separating the acetic acid from the water by the azeotropic distillation.

This invention relates to a 2-way DC convertor by phase shift of voltage regulation at one end and current stabilizing at the other plus PWM control and a control method, in which the 2-way DC converter includes a primary circuit, a switch control and a close-ring control, the primary circuit is composed of inductor L1, a switch tube S1 and serial branch 1, inductor L2, switch tube S2 and serial branch2, two auxiliary switch tubes Sa1 and Sa2, a clamp capacitor Cc and a composite branch 3, switch tubes S3 and S4 and serial branch 4, bleeder capacitor Ca and Cb, a serial branch 5 and an isolation transformer, the switch control circuit is composed of a phase shift control chip, a monostable trigger8 and a PWM control chip 9, the close ring control part is made up of a phase shift angle close ring control loop and a duty ratio close ring control loop, characterizing that: 1, suppressing the voltage peak of the tube, 2, reducing the circumfluence loss of the converter to guarantee the soft switch in the total load sphere, 3, the uncoupling control of the phase shift angle and the duty ratio realizes 2-way free flow of energies.