US 4,065,967 AGranted

Silo level indicating system

AssigneesRobert E. Kirkpatrick, Curtis C. Weaver

InventorJohn T. Beeston

Life of this patent

Estimating the term…

Loading patent…

Abstract

The silo level indicating system includes a plurality of temperature indicating sensor units placed on the outside wall of a silo at vertically spaced positions. Each sensor unit and an adjacent portion of the surrounding sidewall is thermally insulated from the atmosphere so that a sensor unit is responsive to the temperature on the inside of the silo at the thermally insulated wall portion. The air within the silo above the level of material is at the same temperature. Thus, in a comparison of the temperature within the silo opposite each sensor unit to that of a reference sensor unit situated at the top of the silo, so as to be above the uppermost level of the material in the silo, a temperature differential between the reference sensor unit and a compared sensor unit indicates the presence of material at or above the compared sensor unit.

Claims9

Dependent claims

A method for indicating the level of material in a silo or the like having an upstanding sidewall, comprising:

a. mounting a plurality of temperature sensors externally of the silo and in a heat transfer relation with the outside surface of the sidewall at vertically spaced portions thereon including mounting a first one of said sensors above the top level of material in the silo,
b. a thermal insulation enclosure for thermally insulating each of the sensors and the respective portions of the outside surface of the sidewall from the ambient temperature, whereby the temperature at a sensor outside the silo and the temperature inside the silo opposite the respective wall portion are substantially the same,
c. producing a reference signal indicative of the temperature at said first sensor and communicating said reference signal to a level indicator means,
d. producing a signal indicative of the temperature at a selected one of the other sensors and communicating said signal to the level indicator means,
e. comparing said signal with said reference signal in the level indicator means, and
f. visually indicating the existence of a temperature difference between the temperatures at said first sensor and said selected sensor.

3 more elements

A material level indicator for a silo or the like having an upstanding sidewall, comprising:

a. a plurality of temperature sensors,
b. means mounting said sensors each in a thermal insulation enclosure externally of the silo and in a heat transfer relation with selected portions of the outside surface of the sidewall at vertically spaced portions thereon for producing signals indicative of the temperature at the respective sensors, with a first one of said sensors located to produce a reference signal indicative of the temperature of the air inside the silo above the material,
c. insulator means for thermally insulating each temperature sensor and the respective selected portion of the outside surface of the sidewall, whereby the temperature at a sensor outside of the silo and the temperature inside the silo opposite said respective portion are substantially equal,
d. electrical comparator means connected in an electrical circuit with said first sensor to receive the reference signal,
e. means for connecting the electrical comparator means to a selected one of the other sensors to receive the respective signal therefrom,
f. said electrical comparator means effective to compare said respective signal with the reference signal to produce an output signal indicative of any difference between the temperature at said selected sensor and the temperature at said first sensor, and
g. means energized by said output signal to visually indicate the existence of a temperature difference.

4 more elements

Dependencies are inferred from the claim text.