STOKER CONVEYOR SYSTEM HEATING PLANTS

Abstract: This invention relates to a gearing and overload safety device for use in connection with worm conveying of solid fuel. The novelty of the invention consists in a drive system for a stoker worm, which system has a high gear ratio and a minimum of power loss, and in a spring for adjustment of the maximum load, which spring simultaneously acts as an overload safety device for the stoker worm. Also, the system is of simple construction with few wearing parts.

Description: STOKER CONVEYOR SYSTEM HEATING PLANTS, Fields of application of the invention. This invention relates to a gearing and overloading safety system for worm conveying of solid fuel. The present invention is especially well suited for stoker furnaces needing very high gear ratios and rapid change of gears. This may be desirable in the case of various volume/weight ratios. Known technique. Existing stokers of various makes most often use a gear ratio of 600:1. The first step in the change is a worm gear with a ratio of 100:1, and then a chain gear with a ratio of 6:1. This method gives a great loss of power and a great moment. If the worm is blocked by a foreign body the motor must stop, or possibly the safety pin is cut, or at worst the chain breaks if it is worn. The technical problem to be solved. The known techniques suffer the drawback that the chain is caused to break or that the motor seizes as a consequence of a possible blocking of the worm. The purpose of the present invention is to provide an improved stoker system. A system of simple construction, which has a high gear ratio with a minimum of power loss, and which has a spring for adjustment of maximum load, and where the said spring at the same time acts as an overload safety device for the worm conveyor. The new technique. The novelty according to the invention is the use of a crank movement to pull the idling bearings which pull the worm a distance forward, and on the return stroke the worm comes to a standstill. Whether the rotation of the worm is caused by push or pull a safety arrangement in the form of a compres¬ sion spring is to be used in push rotation. In the case of pull rotation the drive arm is prolonged so that the spring is mounted on the other side of the gear arm. which thus makes the spring function as a compression spring. Furthermore, a rapid change in the gearing can be effected by changing the length of the drive arm, either by moving the push/pull rod into holes or infinitely variably in a slit. The overload safety device can, in principle, run endlessly without damage to vital parts. The technical effect. By applying the above-mentioned technique the result will be a functional heating plant, which is simple of construction and has a conveyor system consisting of few components. The invention itself and the forms of embodiment are ex¬ plained below with reference to the drawing. Figures. Fig. 1 shows a fuel hopper with a stoker conveyor system. Examples of embodiment. Fig. 1 shows the stoker conveyor system mounted on a fuel hopper, and which consists of an idling bearing on which is mounted a gear arm and a drive arm with an overload safety device. It will be seen that the drive arm with the overload safety device (1) is loosely mounted on the gear change arm (2). This makes it possible to change the gearing, which will cause a change in the speed of rotation of the stoker worm body (4). The gear change arm (2) is built integral with an idling bearing (3), which is mounted on the stoker worm (4) itself. The whole stoker conveyor system is driven by an electric motor (5). The electric motor (5) transmits the drive to the drive arm (1) via an eccentric disk (6). The drive arm (1) is of a cylindrical construction with an overload spring (7), and by means of the tensioner device (8) it is possible to change the maximum load of the overload safety device.

Claims: Claims 1. Stoker conveyor system for heating plants consisting of a drive arm with an overload safety device (1), gear change arm (2) and an idling bearing (3), which system is novel in that it has a high gearing ratio with a minimum of power loss. 2. Stoker conveyor system according to claim 1, which is novel in that it incorporates a spring (7) for adjustment of the maximum load and at the same time acts as an overload safety device for the stoker worm (4). 3. Stoker conveyor system according to claim 1, which is novel in that the gearing ratio can be changed in situations where the difference in the weight/volume ratio is great. 4. Stoker conveyor system according to claim 1, which is novel in that it is of simple construction and consists of few wearing parts.

Inventors: JOERGEN OVERDAHL PEDERSEN, JOERGEN, OVERDAHL, PEDERSEN
Applicants: JOERGEN OVERDAHL PEDERSEN, JOERGEN, OVERDAHL, PEDERSEN
Application year: 1995
Main classification: F23K3
IPC codes: F23K3