Jack Ruckenstein

overview

My final-year Capstone team and I were commissioned by the Spearhead Hut Society to design a propane-powered device that would turn snow into drinking water more efficiently than their current snow melting methods. It was intended for use at their Kees and Claire Memorial Hut in Whistler, BC with potential to expand to more huts in the future.

Old Snow Melting Method

Indoors on a small, open-flame burner

Conventional 2-5QT pot

Uncontrolled heat loss to surroundings, vapour diffusion through building enclosure, small batch size

New Snow Melting Method

Outdoor with a large, contained + insulated 200,000BTU burner

Large 60QT pot

Insulated, multi-chamber design

Exhaust gas recapturing via enclosed surrounding layer with baffles

Large particle filter

Outlet drain with conventional sillcock valve

Inner Layer

The innermost layer acts as the combustion chamber, containing the heat generated by the burner flame below the pot. The chamber is open at the bottom to allow air intake for combustion and enclosed at the top with exhaust vents to control the flow of combustion gases out of the system.

Baffles

Inner Layer

The baffles were designed with an approximate 65% open area at each layer to slow the exhaust gas flow around the pot and promote turbulence, increasing convective heat transfer into the pot. The 65% open area was selected to balance improved heat transfer with reduced back pressure, helping maintain proper air-fuel mixing at the burner.

Outer Layer

Inner Layer

Outer Layer

The outer enclosure incorporated a 5.5 inch layer of Rockwool insulation to minimize heat loss from the system. Rockwool was selected due to its fire-resistant properties, high thermal resistance, and suitability for high-temperature applications.

Additional Features

Large Particle Filter

A circular perforated 1/8 inch aluminum disk was cut to fit snugly within the pot and act as a coarse filter, allowing meltwater to drain while preventing larger debris and snow particles from exiting the system.

Gas Shut Off Valve

A timed gas shut-off valve was added to the assembly so users can set the desired run time and allow the device to operate until the batch is complete. This prevents the burner from running longer than necessary and reduces unnecessary propane consumption.

Igniter

A battery-powered, replaceable igniter was integrated near the burner assembly to provide a simple and reliable ignition method for starting the snow melting process.

Manufacturing

Inner Layer

Remaining Enclosure Components

Inner Layer

The inner enclosure was fabricated by welding together four 18-gauge 304 stainless steel panels.

304 stainless steel was selected for its corrosion resistance and ability to withstand elevated temperatures, since this layer is directly exposed to the burner flame and combustion exhaust gases.

Baffles

Remaining Enclosure Components

Inner Layer

Three layers of triangular, perforated baffles were waterjet cut from 18-gauge 304 stainless steel and welded into the corners of the inner enclosure. Each layer consists of four baffles designed to redirect exhaust gas flow around the pot.

304 stainless steel was selected for its corrosion resistance and ability to withstand elevated temperatures.

Remaining Enclosure Components

The outer enclosure was fabricated from four welded 0.05 inch 5052 aluminum panels, with waterjet-cut 5052 aluminum sheets used for the top and bottom covers.

Aluminum was selected for the majority of the enclosure to minimize weight while providing sufficient corrosion resistance, thermal durability, and manufacturability.

Pot + Burner

Large Particle Filter

Remaining Enclosure Components

A 60 qt aluminum pot and mild steel 200,000 BTU burner base were purchased as a set to reduce manufacturing costs, simplify integration, and minimize liability associated with custom burner manufacturing.

Aluminum was selected for the pot due to its high thermal conductivity, allowing heat from the burner flame to transfer more effectively into the snow.

Large Particle Filter

A circular, perforated disk was waterjet cut from a 1/8 inch thick sheet of 5052 aluminum to act as a coarse filter within the pot.

Four support legs were waterjet cut from the same sheet and welded to the underside of the disk to create a stable base, with cutouts incorporated to allow meltwater to flow freely toward the outlet.

Outlet Assembly

Large Particle Filter

The outlet assembly was constructed using off-the-shelf plumbing components to reduce manufacturing costs and simplify assembly.

It consisted of:

x1 Bulkhead Fitting
x1 45° Elbow Coupler
x1 12" Pipe Fitting
x1 Sillcock Valve