| 摘要 |
Method and system for motoring and obtaining information about quantity and characteristics of cementitious material In a rotating mixing drum. The present invention involves analysis of a sequence of values corresponding to a waveform reflecting the hydraulic pressure required to turn a concrete mixing drum at successive instances during rotation. Preferred embodiments involve the conversion of this time-domain data into the frequency-domain. Behavior of multiple harmonics can be examined in real time and further information obtained regarding physical properties of the concrete. Rheology or other properties can be adjusted by introducing a liquid into the concrete, based on a comparison between time-domain and/or frequency-domain values derived from a sample concrete in the drum and previously stored time-domain and/or frequency-domain values, which are preferably correlated with physical characteristics of concrete, such as slump, slump flow, load weight, and other factors. |
| 主权项 |
1. A mixing system comprising:
a mixing drum having an inner drum wall and at least two mixing blades mounted on the inner drum wall for mixing a provided concrete contained within the mixing drum; a drive means for rotating the mixing drum containing the provided concrete at constant speed SC1 in the range of 1-25 revolutions per minute; a sensor for providing a sequence of values over time corresponding to the energy required by the drive means to rotate the mixing drum, the provided sequence of values enabling a computer processing unit to detect shape transitioning in the waveform data corresponding to concrete flowing over the at least two blades mounted in the drum within one rotational cycle of the mixing drum; a data memory storage location having waveform data derived from a previously stored sequence of values over time corresponding to the energy required to rotate a mixing drum containing a previous concrete as monitored by a sensor during rotation of the mixing drum at a frequency of at least 10 times constant speed SC1 of mixing drum rotation, the stored waveform data enabling a computer processing unit to detect shape transitioning in the waveform data corresponding to concrete flowing over the at least two blades mounted in the drum within one rotational cycle of the mixing drum; and a computer processing unit which performs the following functions:
monitors at a frequency of at least 10 times constant speed SC1 of mixing drum rotation the sequence of values provided by the energy sensor to obtain waveform data containing shape transitioning in waveform data corresponding to concrete flowing over at least two blades mounted in the drum within one rotational cycle of the mixing drum rotation, and corresponding to the amount of energy required by the drive means to rotate the mixing drum containing the provided concrete;analyzes the provided sequence of values in the time domain, the frequency domain, or in both the time domain and frequency domain, for variations in waveform data within one rotational cycle of the mixing drum;compares waveform data variations within the provided sequence of values to waveform data variations within the previously stored sequence of values; andadjusts the slump, slump flow, or other property of the provided concrete by introducing a liquid into the mixing drum containing the provided concrete based on the comparison of compared waveform data variations in provided and previously stored sequences of values; the waveform data variations being correlated with at least two properties or conditions of the concrete or mixing drum selected from (a) load weight, (b) load volume, (c) concrete density, (d) concrete air content, (e) concrete slump, (f) concrete slump flow, (g) concrete flow table value, (h) concrete rheology selected from yield stress, viscosity, and thixotropy, (i) segregation of concrete components, (j) concrete setting, (k) inclination of the mixing drum, (I) size and configuration of the internal drum structure; and (m) build-up of concrete in the drum. |
