The electrolyzer shown in Figure 1 is based on the common-duct series-cell electrolyzer concept. It uses an alkaline (NaOH, KOH) electrolyte to split water into hydrogen and oxygen components very efficiently. The produced hydrogen and oxygen gasses are not separated to separate containers, but kept mixed. The produced oxyhydrogen gas is a stoichiometric mixture of hydrogen (2 parts vol.) and oxygen (1 part vol.) and can be combusted in vacuum. The combination of series-cell topology is very efficient, because it allows the cells to operate as close to their optimal cell voltage (1.47V) as possible. The electrolyzer runs fairly cool, at about 30-50 C depending on the current and electrolyte. The electrolyzer shown has about 80-90% total efficiency when all things are considered (ambient temperature, ambient pressure, accurate measurement of gas volume and current) when powered by straight DC. Pulsing (PWM) or modulation of the input voltage waveform will increase the performance further, as it is known that in the beginning of each pulse larger current flows than in the steady state condition, thus lowering the cell voltage needed to push thru a certain amount of current and increasing the efficiency slightly. There are also claims of various resonance phenomena that supposedly dramatically increase the gas production rate vs. input current when the electrolyzer is driven with a certain type of PWM rich in harmonics. The electrolyzer has 11 cells with a target input voltage of about 12.9-14.1Vdc depending on temperature. This makes the cell voltage about 1.85-2.0V.

FIGURE 1

stainless steel (316 grade) 5” X 7”. A .375” gas vent hole is drilled in each plate. The electrolyte level is always about .900” below the gas vent hole. There is a .125” diameter liquid level equalization hole drilled in the bottom of each plate. The plates were sanded with an orbital sander to expose clear metal and then cross-hatch pattern was “engraved” on the plates with a rough file attached to a wooden block. This is to increase the active surface area of the plates and seems necessary for ultra high efficiency. Other methods to increase plate area exist as well.

FIGURE 2

Electrolyzer construction The eleven electrolyzer plates (Figure 2) are 12 GA

Figure 3Soft Red Rubber gaskets Twelve gaskets ( Figure 3) were cut out of .125” thick soft and transparent Red Rubber sheet with an Exacto knife.

FIGURE 3

Figure 4 The full size gasket template is printed and is taped to the red rubber material for cutting.

FIGURE 4

Figure 5 With a straight edge and an Exacto knife cut out the gasket .

FIGURE 5

Figure 6 PVC end plates

The end plates ( Figure 6) were cut out of ½” thick PVC plate. The size of the plates is 8” X 6”. Sixteen .250 holes were drilled for ¼-20 X 3 ½” size stainless steel through-bolts. A ¼” pipe thread was drilled and tapped for the gas vent hole(bottom) and a 1/8 pipe thread hole for fill (top).

FIGURE 6

FIGURE 7End plate with the ¼-20 X 3 ½ Stainless Steel bolts installed.

FIGURE 7

FIGURE 8A 3/8” Nylon hose is slid over the bolts to isolate the bolts from the plates and hold the plates in place. The Nylon hose pieces are 2” long.

FIGURE 8

Figure 9The first gasket is installed on the end plate.

FIGURE 9

Figure 10The first stainless steel plate and one PVC spacer ring are shown in Figure 10. There is a PVC spacer ring also between the PVC end plate and first SS plate. This is the First Negative Plate.

FIGURE 10

Figure 11 The stacking process of the plates. The first plate (Negative) and gasket are installed.

FIGURE 11

Figure 12 Alternate plates and gaskets in the stacking process.

FIGURE 12

Figure 13Shows the second electrode plate being installed. This is the Positive Plate.

FIGURE 13

Figure 14 The stacking process almost complete and ready for the last electrode plate.

FIGURE 14

Figure 15Last Plate installde and ready for the second PVC End Plate. This is also a Negative Plate.

FIGURE 15

Figure 16The second end plate installed.

FIGURE 16

Figure 17The completed cell

FIGURE 17

This is a list of suppliers for the material need to build this cell.

PVC End Plates http://freckleface.com/shopsite_sc/store/html/index.html

Stainless Steel http://www.onlinemetals.com/

Stainless Hardware http://www.boltdepot.com/Default.aspx

Rubber Gasket http://rubbercal.com/Product_line.html