3B Scientific Steam Engine G User Manual

Page 2

•

Only put the steam engine into operation if all of the
components are in perfect condition and their func-
tionality is assured. Special attention must be made
to ensure that there are no cracks or any other dam-
age to the glass boiler

•

Only use distilled water that has been demineralised
as per VDE 0510. If conventional tap water is used the
associated deposits that form on the safety-relevant
components mean that functionality can no longer
be guaranteed.

•

Carefully pour alcohol into the burner

. Make sure

that nothing spills.

•

Never pour in alcohol while the wick is still glowing or
if there is any other open flame in the immediate
proximity.

•

Seal the bottle of alcohol immediately after use.

•

Keep away from the open flame. Be careful! Only ex-
tinguish the burner flame by means of the attached
cover. Do not blow on the flame in the proximity of
the boiler, as any sudden temperature change could
cause the boiler to crack.

•

The boiler may not be heated unless it is filled with
water. For that reason it is important to extinguish
the lamp’s flame before it boils dry.

•

Do not touch any components steam carrying, par-
ticularly the boiler

, hoses

, steam

exhaust pipe

and support frame

. Do not

touch the spirit burner

during or after operating

the steam engine either. Risk of burns!

•

Let the steam engine cool before storing.

2. Description, technical data

The oscillating steam engine has been designed for use
in a training and educational environment. In order that
individual operations and dynamic processes should be
observable, particular emphasis has been placed on trans-
parent construction. For that reason the main cylinder

and boiler

are made of heat-resistant special glass

and the flywheel

is made of acrylic. The hardened

crankshaft

and the connecting rod

are ball-bear-

ing mounted. The graphite piston

runs dry in the

operating cylinder – i.e. without any added lubricant. For
that reason the steam engine runs very quietly and safe-
ly for long periods, providing a mechanical power out-
put of approx. 1 W. The safety valve

is located in the

boiler cap

. It opens as soon as the boiler pressure

exceeds 1.0 bar. In addition, the machine is also equipped
with a second, independent excess pressure safety mech-
anism. Up to a pressure of approx. 1.5 bars the steam is
forced into the ducts of the support frame

and dis-

charged via the condensation hose

. When the pres-

sure exceeds 1.5 bars the cylinder flank

is forced away

from the frame because the tension in the spring

overcome so that the steam can flow unimpeded out of
the steam inlet hole in the frame.

Piston diameter:

19 mm

Piston stroke:

10 mm

Boiler diameter:

50 mm

Boiler volume:

50 ml

Operating time per filling:

approx. 20-25 mins

Speed:

800 rpm

Mech. Power output:

approx. 1 W

Max. operating pressure:

0.5 bars

Trigger pressure
of the safety valve:

1.0 bars

Minimum boiler
bursting pressure test:

2.0 bars

3. How the apparatus works

Unlike a slide-valve steam-engine, an oscillating steam
engine has a cylinder that rotates on a central shaft caus-
ing steam inlet and outlet ducts to open and close. Water
in the boiler begins to boil, and thus steam is generated.
The steam flows via the steam inlet hose

into the

frame then through the steam inlet hole. As soon the
opening of the cylinder is fed with fresh steam, steam
flows into the cylinder and displaces the piston (Fig. 1, a).
When the piston reaches its lowest point, the steam ducts
are closed. This slack point is passed thanks to the inertia
of a flywheel (Fig 1, b). In the next phase, the piston moves
back, opens the steam outlet and pushes out the steam

General safety standards applicable to steam engines

Specific conformance of steam engine U10055

5. An adjustable spring-operated safety valve made of

non-rusting material with a safety threshold of no
more than 3.0 bars (double the operating pressure)
must be provided.

5. This unit is equipped with an adjustable spring-ope-

rated safety valve made of non-rusting material with
a safety threshold of 1.0 bar (double the operating
pressure)

6. The bursting pressure of the boiler should be no less

than 3-times the operating pressure.

6. The boiler’s bursting pressure is at least 1.5 bars (at

least three times the operating pressure). Each boiler
is checked for safety and leaks by means of a burst
pressure test (2 bars+).

7. The water level must be visible, if possible, with the

aid of an inspection window.

7. The water level is visible at all times because of the glass

boiler.

8. An easy to understand instruction sheet is required

plus a label with the name or logo of the manufactu-
rer.

8. An instruction sheet is supplied with each apparatus.

An appropriate silk-screen printed label is located on
the base plate.