Patent GB-114165-A (GB)
Title: Improvements in Apparatus for Compressing Gas or Air.
Inventor: SCOTT-SNELL CHARLES
IPC: F23D99/00
Filed: 1917-01-15
Abstract: 114,165. Snell, C. Scott-. Jan. 15, 1917. Pressure obtained by combined heating and cooling of gases; actuated pumps by fluid-pressure motors; valves, arrangement and actuation of.-Apparatus for compressing air or gas for use at a Bunsen burner comprises a reservoir containing gas in which pressure is generated by the direct application of the heat of the burner and a gas compressor, including a cylinder and a displacer, which is operated by heated gas from the reservoir and delivers cool gas to the reservoir to maintain the pressure therein and provide a supply for use in the burner, such as an incandescent gas burner. In one form of apparatus, an air reservoir A, Fig. 1, is arranged immediately over the burner and may be provided with circulation guides as shown for the heated air therein. Above the reservoir is a cylinder B, which may be lined at its lower part with non-conducting material and is provided with a displacer piston C connected by a hollow rod C<1> to differential diaphragms D<1>, D<2>, The space above the piston G communicates with the space below the larger diaphragm D<1> and through the hollow rod C<1> with the space above the smaller diaphragm D<2>. Linkwork G connects the piston-rod to a plug cock F provided with a spring or balance weight and arranged to move suddenly. When the burner is lighted, heated air passes from the reservoir through a pipe K to the cock F, which has ports in the position shown opposite the pipes K, E<1>, L, the pipe E<1> leading to the top of the cylinder and the pipe L through a chimney J and under the reservoir to a superheater A<2> and the bottom of the cylinder. The piston C is raised and cool air passes into the reservoir. At the top of the stroke, the cock F is turned to close the pipes E<1>, K and open the pipe L to the atmosphere so that the air under the piston is expelled and the piston falls, fresh air being admitted by the valve E to the top of the cylinder and the cock F being restored to its original position at the end of the stroke to cause a repeat of the cycle. When the reservoir pressure reaches a predetermined amount, compressed air passes therefrom by a diaphragm valve H, H<1> to the burner, a weighted blow-off valve H<2> preventing excessive pressure. In another form, the cylinder is divided into two parts B<1>, B<2>, Fig. 2, with pistons C<1>, C<2> connected by a rod N and provided with differential diaphragms D<1>, D<2>. Tappet valves F<1>, F<2> are provided and actuated through a rod and a lever G with a spring-blade Q operated by pins on the rod N, the spring-blade yielding until supported by one of the claws on the lever. Air passes from the reservoir A by the pipe K and valve F<2> to the top of the cylinder B<2> and thence by a check-valve P and pipe L, passing through the chimney J and under the reservoir, to the bottom of the cylinder B<1> to raise the piston C' and force air from the cylinder B<2> through the pipe K to the reservoir. The valve F<2> closes at the end of the stroke and the valve F<1> opens to exhaust the air under the piston C<1> to atmosphere. Air passes to the burner through a valve H as before, and fresh air is admitted through a valve E in the piston C<2>. The cylinders may be arranged side by side, the pistons being connected by rods and a rocking lever. In another form, the cylinder is subdivided and provided with a number of pistons connected by a rod which operates tappet valves through a lever with a blade spring and a rod, these valves controlling admission of air from the reservoir to the spaces under the pistons and exhaust therefrom to atmosphere. A pipe connected to the spaces above the pistons is provided with check valves for admission of fresh air from the atmosphere and delivery of compressed air to the reservoir. The reservoir may be divided into inner and outer parts A, A<1>, Fig. 3<A>, cool compressed air being delivered past a valve T into the outer part and passing therefrom past a valve U to the inner part. When exhaust to atmosphere is not permissible, as when gas other than air is compressed, a condenser inside or outside the cylinder is provided. The cylinder B, Fig. 4, has a displacer piston C with a rod connected to a piston diaphragm D' and actuating a plug cock F with ports open in the position shown to a pipe K from the reservoir A and a pipe L to the space under the piston C. When the piston C is raised, gas is forced past a check valve T to the reservoir and towards the end of the stroke the cock F is turned to close the pipes K, L. Momentum causes slight continued movement of the piston, and, on the recoil, hot gas passes up the annular space between the piston and the cylinder and through a valve V in the upper packed portion of the piston to the cool upper end of the cylinder, where it is condensed, and the piston falls. The condensation causes inflow of gas from a supply through a valve E, and eventually the cock F is restored to its former position and the cycle recommences. Air may also be compressed by this apparatus, admission at the valve E being from atmosphere. If a separate condenser W is used, the plug cock F has extra ports to open a pipe Y from the bottom of the cylinder to the condenser at the top of the stroke and allow the hot air to pass through the condenser to the top of the cylinder, the valve V not being provided. When the piston is in its bottom position, the condenser is cut off by the cock F and a check valve X. As shown, the hot gases from the burner pass through small tubes Z, traversing the reservoir, and an annulus Z<1> to the chimnevs J. Other forms of valves may be used and the apparatus may be made double-acting.