FLOOR SCRUBBER CLEANING SYSTEM USING COOLANT FOR HEATING A CLEANING SOLUTION

A floor scrubber cleaning system includes a combustion engine powered floor scrubber using at least one rotating scrubbing brush/pad. A tank or reservoir is used for supplying a cleaning solution to the scrubbing brush/pad for cleaning a floor. A heat exchanger uses coolant from the combustion engine to heat the cleaning solution where it is dispensed directly onto the floor.

FIELD OF THE INVENTION

The present invention relates generally to a system for heating cleaning solution used in a floor scrubbing machine.

BACKGROUND

Using hot water in a cleaning solution is widely accepted to enhance the process of cleaning.FIG.1illustrates a prior art diagram of an example of an industrial floor scrubbing machine100that uses one or more cleaning disks or brushes101that move in a circular, orbital or cylindrical motion to clean the floor. In order to provide an improvement in industrial floor scrubbing effectiveness, a heated solution system is used in gasoline, diesel or liquid propane gas (LPG) powered industrial floor scrubbers.

The heat source of heated cleaning solutions industrial floor scrubbers is important since manufacturers have been unsuccessful in their attempts to heat the solution being applied to the floor during scrubbing. These methods include utilizing the heat from the exhaust system or by employing electric heaters on the machine. In all cases, it is difficult to design a heating system robust enough to heat the number of gallons per minute of solution required for the typical floor cleaning process. To be useful, the temperature of the solution must reach a threshold level without being too hot to enhance the cleaning process.

Accordingly, better solutions and methods are required to better heat the cleaning solution so it may be more effective during scrubbing.

DETAILED DESCRIPTION

Embodiments of the present invention include a scrubbing machine having a heat exchanger, which is attached to or is integral with the engine cooling system, is used to heat the cleaning solution. Industrial floor cleaning machines typically include a cleaning solution reservoir or tank which holds a substantial amount of cleaning solution and a solution delivery system used to apply the solution in controlled amounts to the floor to be cleaned. The solution delivery system can be a gravity fed system or a pressurized system through the use of one or more pumps. One or more valves are typically used to turn on, turn off, and to control the amount of cleaning solution to the floor. Various methods are used to apply the solution to the floor. Scrubbers using one or more disk shaped scrub brushes typically deliver the solution to the center area of the brush and/or brushes. The scrub brushes move in a linear, rotational or orbital motion. Scrubbers equipped with cylindrical shaped scrub brushes typically employ a solution delivery tube with holes spaced in a specific pattern to apply an even amount of solution to the floor in front of the scrub brushes.

Skilled artisans will recognize that in a floor scrubber hydraulic system, the volume of hydraulic fluid far exceeds that of engine coolant in liquid-cooled engine systems. Unlike engine coolant, hydraulic fluid is generally not temperature-controlled by a thermostat. Instead, it is engineered to function at the maximum steady-state target hydraulic fluid temperature under peak working loads. Consequently, the designed configuration necessitates a prolonged duration to elevate the hydraulic fluid to its maximum temperature and hydraulic fluid is not a good choice in applications in heating a cleaning solution with a heat exchanger.

In contrast, the thermostat in a liquid-cooled engine is configured to fully bypass the engine coolant radiator when the coolant is below the minimum target temperature, typically 165° F. This operational feature enables the liquid, serving as the heat source for heating the cleaning solution, to rapidly attain elevated temperatures. As a result, the use of engine coolant in a liquid-cooled engine facilitates a more expeditious attainment of an effective hot cleaning solution early in the cleaning cycle, surpassing the concept of using hydraulic fluid to heat cleaning solution in a floor scrubber.

This difference is particularly pronounced when the hydraulic system that operates at minimum load, considering that hydraulic systems seldom operates at maximum hydraulic load. Moreover, the energy transferred using the engine coolant in a liquid-cooled engine far exceeds the energy required to heat the cleaning solution to temperatures close to that of the engine coolant. This surplus heat energy ensures that even during engine idle, there is ample thermal energy to efficiently heat the cleaning solution.

Typically, the ideal operating temperature for hydraulic fluid in hydraulic systems is 140° F. or below. In contrast, the temperature of engine coolant in a liquid-cooled engine system is regulated by a thermostat paired with a radiator, typically operating within the range of 165ºF to 190° F. and sometimes greater than 190° F. The viscosity of the engine coolant is typically less than that of the hydraulic fluid. These nuanced thermal characteristics collectively contribute to a more efficient and more consistent, solution heating system when utilizing engine coolant compared to hydraulic fluid in a floor scrubber equipped with an engine-driven hydraulic power system.

FIG.2illustrates a cleaning system200using engine coolant and heat exchanger according to the various embodiments of the invention. The cleaning system200uses the engine coolant201to cool a combustion engine203though its cylinder wall jacket205. The coolant201is stored in a radiator207typically configured in front of the combustion engine203. Ambient air209moves toward the front of the engine cools engine coolant201using a fan211driven by the combustion engine203. A coolant pump213facilitates movement of the coolant201though tubing toward and/or away from the engine203.

In use, a heated liquid such as a hot engine coolant leaving the cylinder wall jacket205is also directed toward a heat exchanger215. Within the heat exchanger215, a cleaning fluid from within a scrubber solution tank217is directed near and in close proximity to the hot coolant without mixing. The heat from the engine coolant is used to heat and/or increase the temperature of the cleaning solution though thermodynamics and/or heat transfer. Thereafter the heated cleaning solution can be pumped or otherwise directed to a scrub head on the scrubber so that it can be distributed on a floor for use in cleaning. Those skilled in the art will recognize the heated cleaning solution is much more effective in scrubbing dirt from a surface and provides a better overall cleaning result.

FIG.3AandFIG.3Billustrate an example of a plate type heat exchange as used in an embodiment of the invention. The plate heat exchanger includes a housing or body allowing hot engine coolant to enter on one side of the body and exit on the opposite end of the body while transferring heat to water and/or cleaning solution moving adjacent to the hot engine coolant. The exchanger is comprised of a series of stacked plates allowing heat to transfer through each plate. Those skilled in the art will recognize that although a brazed plate heat exchanger is illustrated inFIG.3AandFIG.3B, a coil liquid-to-liquid heat exchanger or other type of liquid-to-liquid heat transfer device can also be used.

FIGS.4A and4Billustrate an example of a plate type heat exchanger mounting configuration used in an embodiment of the invention. When heat exchangers are used in vehicular application without shock absorbers, it is often necessary to mount the heat exchanger in a manner so it can absorb forces and vibrations and prevent damage. In use, the heat exchanger215is mounted to the machine with the mounting plate bracket401. The heat exchanger215is secured to the mounting plate bracket401with bracket404. Vibration isolators406are used to protect the heat exchanger215from machine vibration and potential abrasion wear from the brackets401and404. Bracket404is secured to mounting plate bracket401with springs407and hardware408,410, and416to provide a fixed clamping force while accommodating size variation due to manufacturing tolerances of heat exchanger215. Mounting plate bracket401is secured to isolator mount402with isolators405in between401and402and hardware411,412,413, and414to further protect heat exchanger215from machine vibration. Isolator mount402is secured to the machine with u-bracket403and hardware415and416.

Thus, the present invention is directed to a floor scrubber cleaning system that includes a combustion engine powered floor scrubber using a radiator holding liquid coolant for use in cooling the engine. At least one rotating cleaning implement such as a scrubbing brush or cleaning pad is used for removing dirt from a floor where a holding tank holds cleaning solution sprayed onto a floor. Those skilled in the art will recognize the scrubbing brush typically moves in cylindrical orbital motion. Either a brush or pad will move in a manner so to be parallel with the floor surface. A pump then directs the cleaning solution to the rotating scrubbing brush(s)/pads and a heat exchanger is used for heating the cleaning solution such that the cleaning solution is directed from the holding tank though the heat exchanger where heat for the engine coolant is transferred to the cleaning solution before being applied to the floor.