Smoke Detector for Portable Heaters and Heat Tapes
( Defender I )
For years the Consumer Product Safety Commission has provided information and statistics on the incidence of fires caused by both the malfunction and misuse of space heaters and other devices. Consumers are not ensuring their own safety through following very basic guidelines and principles regarding the safe operation of such devices. For example, portable heaters, and other devices, such as kerosene and gas based heaters are often in too close proximity to bedding, drapes and other flammable materials. When devices are placed on surfaces that are unreliable such as carpeting as opposed to hard wood surfaces, the probability of fire is greatly increased. It is notable that many older portable heaters and other devices, such as heat tapes do not have an internal “cut off” mechanism to prevent fires due to overheating or malfunctions that exist internally within the device itself. For example, “an electrical short” greatly increases the probability of fire. Also notable is the fact that many heat tapes, or other heating devices are simply not within proximity for human monitoring purposes to prevent fires. In addition to the fires that occur both due to the misuse and malfunction of portable heaters, and other devices such as heat tapes, there is also the issue of the unabated incidence of carbon monoxide poisoning that occurs due to the poor ventilation of kerosene and gas based devices. Please refer to:http.//www.anapsid.org/spaceheaters.html The United States Consumer Product Safety Commission ( CPSC ) released a comprehensive report in January of 2004 on the factors noted above. Incidence of injury, death and loss of property is very real, and in most instances avoidable. For example in 2003 there were 10,900 residential fires and 190 deaths associated with portable heaters, and other devices. Additional data reveals that there were 15,500 fires and 40 deaths associated with fireplaces and chimneys. The incidence of carbon monoxide poisoning, due to heating systems that are gas based or kerosene based resulted in about 100 deaths according to the CPSC. The CPSC statistics for 2001, which represents the “average statistics” for such fires, associated with space heaters and other devices, estimated that over 21,800 residential fires occur every year. Approximately 300 people die each year in fires started by portable heating systems alone, not factoring in other devices. For a summary of the compiled reports refer to: http://www.epinions.com/content_2709364868 which provides a comprehensive overview of the statistics and long standing issues and concerns both the CPSC and the National Fire Protection Association (NFPS) has regarding space heaters, gas fireplaces, and other heating mechanisms that have both the potential for creating fires and carbon monoxide poisoning. The need for inproved safety standards to reduce injury and loss of life and property damage is paramount. http://www.nfpa.org/newsReleaseDetails.asp?categoryid=488&itemId=25760.
The United States manufactures and distributes space heaters and other devices in many countries. The impact extends beyond our borders and is therefore a global concern. It is possible to extrapolate the statistics from here in the United States and readily determine that similar circumstances exist in neighboring countries. Due to the factors noted above in detail the present invention provides a comprehensive smoke detector system that can be used in all portable heaters and other devices, including heat tapes. Many of the flaws or issues with the current smoke detectors in use which include all devices mentioned above including heat tapes, is rectified with the current invention, Defender I.
ABSTRACT
A smoke/fire detection system for the detection of smoke or fire produced by a malfunctioning heating tape or other electrical devices. The detector automatically shuts off the power to the affected tape or device and provides an alarm indicating the malfunction and its location to enable repairs to be made. In a preferred embodiment, the detection system includes a computer and a fire extinguisher. The computer determines if a fire is present at a selected location and turns on the fire extinguisher automatically when fire is present.
PRIOR ART
The following are summaries of patents related to smoke detectors and the automatic shut down of power in response to the detection of smoke.
US Patent No. 3,952,294 illustrates an emergency smoke alarm system for transmitting an alarm from a remote location. However, it fails to have a means for cutting off power to a heating element such as a heat tape.
US Patent No. 4,038,649 illustrates a smoke detector with a unijunction transistor which, when a preselected threshold has been exceeded, activates a horn. However, it fails to have a circuit which would specifically cut off a power line to deactivate the heat tape or electrical device.
US Patent No. 4,194,192 illustrates an alarm system that is triggered by multiple sensors which can include a smoke detector. However, it fails to have a specific circuit to deactivate a power line.
US Patent No. 4,694,285 illustrates a combination light socket and smoke / heat detector. However, it fails to have a specific circuit to deactivate a power line.
US Patent No. 4,763,115 illustrates a smoke detector that activates light / alarm systems to direct people to an exit in the event of a fire. However, it fails to have a specific circuit to deactivate a power line.
Commercial GEZE smoke switch control unit RSZ5 is a switch giving a closed contact on activation rather than an open circuit. For the most part, the prior art devices provide alarm circuits to indicate that smoke has been detected, but none of the above mentioned devices are designed to shut down the power to heating elements, and other electrical devices, nor are they adapted to, in addition, provide a remote alarm. These and other shortcomings of the prior art are overcome in the present invention which is described below.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a diagram of a smoke detector connected to deactivate power to a heating tape and other devices when smoke is detected. This is simply one representation of the invention, yet its embodiment is not limited to this one representation as there are several more uses and perspectives to be considered to cover the full scope of the invention’s capacity and capabilities.
SUMMARY
It is an object of the present invention to provide a means for automatically shutting off the power to malfunctioning heating tapes, and other devices to aid in preventing fires. It is an object of the present invention to provide a remote alarm to indicate where a malfunction tape or device is located. It is an object of the present invention to provide a test station to enable the performance of the smoke detector to be monitored from a remote location. It is an object of the present invention to provide a means by which one smoke detector can monitor multiple heating tapes, and other devices. In a preferred embodiment, the detector is a system which includes a computer and a fire extinguisher. The computer determines if a fire is present at a selected location and turns on the fire extinguisher automatically when fire is present.
DETAILED DESCRIPTION OF THE INVENTION
Figure 1 is a diagram of a smoke detector connected to a switch that controls the power that is being delivered to the electrical device. The smoke detector causes the switch to open when smoke is detected. This diagram includes a heating tape 1A wrapped about a pipe 1B. Such heating tapes contain heating elements and are used to prevent pipes from freezing in winter. Power is supplied to the heating tape by way of an input power line 4 which passes through a switch 2 to a second power line 5 that is connected to the tape. A smoke detector 3 is connected to open the switch when smoke is detected. In the operation of the system shown in Figure 1, if the heating tape 1A starts to produce smoke due to a malfunction, such as a short circuit, the smoke is detected by the smoke detector 3. The smoke detector transmits a signal to the switch 2, causing it to open and disconnect the power from the heating tape 1A. The basic detection system shown in Figure 1 helps to provide safe operation of the heating tapes or other electrical devices by preventing fires which would ordinarily occur if this system were not employed. It is possible to enhance the system of Figure 1 by adding a number of components. Each application requires its own particular system configuration which may include either a gathering fan, horn, computer, ARC, GFCI, Current limiting, Carbon monoxide sensors or remote indication and control. Remote indication is an important feature where the smoke detectors are located in areas where personnel are not normally located. With a remote indicator system, not only is the power shut off to the tape or other electrical devices, but personnel are alerted that smoke/fire has been detected and they are advised where to go to rectify the problem before a pipe is damaged from failure to keep it heated. This is a important feature as heating tapes and other devices are usually located in remote areas of a building, such as in a crawl space. If a fire were to start in such remote closed areas, the fire would be difficult to detect initially. The remote indicator panel overcomes this problem. There is also another method of generating an alarm if there is a malfunction, which may be used with the present invention. Current limiting monitors to supply lines determine if there has been a partial or a complete short between the wires in the heating tape or between the wires and the pipe, upon which it is wrapped. If the current imbalance on the lines indicates that there has been a partial or full short circuit this causes the switch to open and it sends a signal to the remote indicator 10. The use of a current detection can make it possible to eliminate the smoke detector as a necessary part of the system. Alternatively, both the smoke detector and the current detector may be kept to provide redundancy or the degree of urgency needed for activating other devices such as a fire extinguisher. The smoke detector and shut off switch can be a installed in the portable heater or device or be externally attached by being built into a single housing that can be plugged into an outlet near the heating tape and thus provide a safe, switched outlet jack for the heating tape. The installation of an automatic fire extinguisher can be used to help ensure proper operation of the detection system. Even if a fire has progressed to the point where it has impacted some of the other power lines in the area, it should be noted that the protection system has this added measure of protection to ensure its operation in a fire emergency. In some cases, there is no person immediately available to receive and respond to the alarm. This automatic system will work to extinguish the fire in the absence of personnel. The five sensors are an arc sensor, a 1R sensor, a smoke detector, carbon monoxide and a line current sensor. Other sensors may be added such as a simple temperature, if necessary, to make a more apt determination in a particular installation. The ARC sensor is used to detect arcs occurring in equipment. Arcs produce a high temperature which can easily cause fire. Arcs are detected by sensing a step in the normal sine wave input of the power supplied to a piece of equipment. An IR detector is an infra-red detector which can detect high temperatures such as those caused by a fire. The higher the temperature of a fire, the higher the IR detector’s output. It detects smoke which usually is present when there is a fire. It is one of the most common types of detectors used to detect the presence of fire. The line current detector detects large current changes in the supply line to an electrical device to indicate possible short circuits which would be a predictor of a possible fire. Characteristics may be changed to suit the application. The output of the computer may be used to disconnect power to any device. The sensors may have dual functions in and can feed the computer as describe above to disrupt power. As is evident there are multiple applications for this invention and therefore should not be viewed in a limited capacity.
