Abstract:
A method and apparatus for reducing the viscosity of a fluidic cementitious mixture, the apparatus including a high voltage source, first and second spaced electrode members electrically connected to the high voltage source and (when energized) define an electrostatic field therebetween. The positioning of particulate cementitious material within the electrostatic field imparts like charges to the cementitious particles. By establishing such an electric field and positioning cementitious particles within the field, the particles may be charged prior to mixing into a hydrated cementitious slurry. Such charging decreases the viscosity and/or enhances the flowability of the hydrated cementitious slurry.
Abstract:
A sprayed-on phosphate cement coating formed from the combination and reaction of a phosphoric acid solution and a base metal solution. The acid solution and base solution may be intermixed prior to spraying, during spraying, or on a substrate. The curing reaction rate of the phosphate cement coating and its final physical properties may be controlled by adding various retardants, accelerants, reducers, wetting agents, superplasticizers, buffers, water reducers, adhesive agents, hardening agents, and/or sequestrants to the precursor solutions. The curing rate and properties of the cement coating may be further controlled by adjusting the temperature of the precursor solutions and/or the target substrate.
Abstract:
A refrigeration system is described in two preferred embodiments. In both embodiments, the refrigeration cycle includes a conventional compressor, condenser, expansion valve and evaporator. The receiver is not in the loop normally. In one embodiment, a pressure differential valve diverts subcooled refrigerant to the receiver only in response to a predetermined difference in pressure between the saturation pressure caused by the ambient surrounding the condenser, plus spring pressure and the pressure within the line leaving the condenser. Refrigerant thus diverted is metered back into the suction side of the system. In a second embodiment, compressed gas exiting the compressor is diverted to the receiver responsive to a pressure differential between saturation pressure caused by condenser ambient plus spring pressure and the pressure within the receiver. The refrigerant thus diverted raises the pressure within the receiver which in turn drives liquid refrigerant back into the liquid line.
Abstract:
A method of controlling the physical properties of cement by adding a predetermined amount of a second phase to a first phase cementitious precursor. The second phase is added in the form of seed crystals having controlled sizes, shapes, and compositions. The seed crystals provide growth sites upon curing the cement for a second phase in the cement body. The curing is accelerated by the presence of the seed crystals. Control of the microstructure of the resulting cement body through controlled distribution and growth of the seed crystals enables the formation of a cement body having precisely controlled physical properties.
Abstract:
A sprayed-on phosphate cement coating formed from the combination and reaction of a phosphoric acid solution and a base metal solution. The acid solution and base solution may be intermixed prior to spraying, during spraying, or on a substrate. The curing reaction rate of the phosphate cement coating and its final physical properties may be controlled by adding various retardants, accelerants, reducers, wetting agents, superplasticizers, buffers, water reducers, adhesive agents, hardening agents, and/or sequestrants to the precursor solutions. The curing rate and properties of the cement coating may be further controlled by adjusting the temperature of the precursor solutions and/or the target substrate.