Keeping particulate matter warm during the winter months creates a major problem for construction workers.
It is an age old problem because for cement and mortar to have the proper strength and workability, the temperature needs to be kept above 40° F.
Early on, sand and other particulates that were used in construction were kept warm by using open fires or by starting fires in cement culverts and piling the particulate material on the culvert.
There are many problems with such approaches to keeping particulate materials warm. Mostly, the amount of heat from such sources is hard to control. Sand can be scorched and made unusable. Water can easily overheated, causing cement in the mix to set too quickly.
In addition, such activities are labor intensive because someone has to build and continuously tend the open fires which can pose safety hazards. Further, they hamper productivity by delaying work until materials are heated. Approaches such as giant electric heating pads and, a second approach heats water in a drum that then works like a hot water bottle to heat the sand and finally, a third activity heats water in a chamber and releases steam to heat the sand. There are many variations of these three approaches.
Such approaches can be found in U.S. Pat. No. 1,631,699 to Selmer which is a sand heating apparatus that comprises a dual sand and water heating element that heats the components simultaneously.
Mayer, in U.S. Pat. No. 571,382 deals with a sand heater which is a furnace and Mullen, U.S. Pat. No. 965,214, that issued Jul. 26, 1910 deals with a sand heater analogous to the furnace in Mayer.
U.S. Pat. No. 1,235,802 to Londelius Jr., that issued Aug. 7, 1917 deals with a water and sand heater comprising water heated pipe arrays.
White, in U.S. Pat. No. 3,176,630 that issued on Apr. 6, 1965, deals with a tent-like structure in which heated water comprising steam is vented through the structure to heat sand contained therein.
Finally, Olsen, in U.S. Pat. No. 6,408,843 that issued Jun. 25, 2002 deals with a box-like device that is used for ground thawing.
Thus, what is disclosed and claimed herein is a material heater, consisting essentially of an elongated housing, wherein the housing consists of an outer shell having at least one wall, a first end and a second end, wherein the first end is movable into and out of the housing, and the first and has an opening through a front wall of said first end.
There is an electrical heating unit housed in the housing. The heating unit has electrical energy supply conduits from the heating unit to an electrical power source.
In addition, the material heater can have a unit for controlling the energy input to the heater.
Turning now to
The first end 5 is removable from the opening 6. A handle 7 is fixedly mounted on a front of the first end 5 for purposes of handling the first end 5.
Referring to
Turning now to
Number 14 designates the general electrical connections and wiring for the thermostat 9, the heating element 13, the limit switch 10 and the like.
The overall length of the heater is about 2 to 6 feet, while the width of the heater is on the order of about 10 inches to about 18 inches. The overall height of the device 1 is on the order of about 12 to 18 inches. The devices are manufactured from metal and it is contemplated within the scope of this invention to use steel having a gage in the range of about 11 to 16, or less depending on, the type of steel used.
The electric heater used in this invention is contemplated to be a heater that has 1250 watts and operates between 60 to 360° F. Such a heater can be, for example, a finned strip heater sold by ZORO, WWW.ZORO.COM.
In use, the device 1 is place on the ground or a trailer and the thermostat is set to the desired temperature. Sand or other particulate material is dumped over the heater and heated. In use, the device 1, and the sand, can be covered with an insulated blanket or cover. Using the Zoro heater, a pile of sand can reach about 1220° F. over a short period of time.
Although the description has been generally based on the use of electrical energy to heat the device 1, it is contemplated within the scope of this invention to heat the device 1 using any type of heating element inside or the housing, such as a finned heater element, tube element, infrared element or oil fueled element.
Two yards of mason sand were dumped onto a trailer over a device of this invention. The heater was set at 150° F. The trailer temperature was 24° F. and the sand temperature averaged over the pile to be 25° to 28° F. The overnight temperature was 22° F. with a wind chill factor of 18° F. After 12 hours, with an insulated tarp covering, the sand, the temperature was 49° F. at the top of the sand pile, and the temperature was 90° F. in the middle of the sand pile.
During the winter of 2014/2015, a heating device of this invention was located under 10 yards of mason sand and the thermostat was set at 250° F. and the sand pile was covered with an insulated tarp. The heater was used non-stop from Dec. 14, 2014 to Feb. 16, 2015 and the sand pile was thawed and warm all of this time showing that the heater of this device is efficient and low cost.
This application is a utility application from U.S. Provisional Patent application Ser. No. 62/315,718, filed Mar. 31, 2016 from which priority is claimed.
Number | Date | Country | |
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62315718 | Mar 2016 | US |