FIELD OF THE INVENTION
This invention relates to a condensate drain for a fire protection sprinkler system of the dry-pipe type, and more particularly, to a condensate drain for a dry-pipe type fire protection sprinkler system that is automatically controlled by a programmable controller.
BACKGROUND OF THE INVENTION
Automatic sprinklers are the most widely used fixed apparatus for fire protection. Automatic sprinkler systems typically comprise a host of sprinklers connected in a systematic pattern over a protected area, an adequate water supply, and an internal piping system. Further, an automatic sprinkler system is comprised of a horizontal array of branch lines which are located in the ceiling of each floor of a building and supply the sprinklers with water. A sprinkler can extend above a branch line, placing the sprinkler close to the ceiling, or a sprinkler can extend below a branch line and be mounted flush with a drop ceiling so that only part of the sprinkler is exposed below the ceiling.
The sprinklers and branch lines are supplied with water via risers that are connected to water mains which are further connected to a municipal water source or other water supply. Water is primarily distributed to the sprinkler either through a wet-pipe system or a dry-pipe system. In a wet-pipe system, typically used in heated buildings, all pipes contain water under pressure for immediate release through any sprinkler that opens. The wet-pipe system contains non-flowing water which poses a higher risk of mechanical damage should the water in the branch lines freeze. However, this risk is not present in a continuous flow system or in a dry-pipe system.
In the dry-pipe system, which is normally used in any area exposed to freezing, branch lines and other distribution pipes contain dry air or nitrogen under pressure. The pressurized gas causes a dry-pipe valve to remain in a closed position at the riser. Water is delivered to the fire through the sprinkler in a dry-pipe system when heat from a fire opens the sprinkler. Once the sprinkler is open, pressurized gases escape and causes the dry-pipe valve to open, thereby allowing water to enter and fill the branch lines. The water eventually escapes through the sprinkler heads.
Both the dry-pipe and wet-pipe systems require means to enable the system to be drained. In the dry-pipe system, it is typical practice to provide an auxiliary drain to facilitate periodic drainage. The primary purpose of the auxiliary drain in a dry-pipe type system is to drain condensate that has collected in the system due to changes in temperature of the ambient air surrounding the risers and lines.
It is known in the art that auxiliary condensate drains are disposed in a riser pipe and have an inlet in fluid communication with the pipe network of the system and an outlet in fluid communication with a disposal system. The inlet and outlet ends of the condensate drain are controlled with suitable valves. A fluid reservoir for collecting condensate from the system is disposed between the inlet and outlet valves. A typical condensate reservoir is formed of a main pipe having a two-inch outside diameter (OD) and a length of approximately 12 inches. The inlet end of the inlet valve is attached to the outlet of a riser of the sprinkler system, while the outlet end is coupled to the inlet of the main reservoir pipe. The inlet end of the outlet valve is connected to the outlet side of the condensate reservoir and leads to a disposal system, thereby allowing discharge of the condensate from the condensate reservoir.
Currently, the condensate drain must be manually operated on a regular basis to relieve the piping system of the accumulated condensation in order to prevent mechanical damage from freezing conditions. As a result, the current system is inefficient, costly to maintain, subject to human error as it requires constant human monitoring and expensive to replace should the system be allowed to freeze and rupture the piping system.
Therefore, a need exists for automatically and reliably controlling an auxiliary condensate drain in a dry-pipe type fire protection sprinkler system so that condensate is timely removed from the sprinkler system.
SUMMARY OF THE INVENTION
Set forth below is a brief summary of the invention that solves the foregoing problems and provides benefits and advantages in accordance with the purposes of the present invention as embodied and broadly described therein.
Generally speaking, a preferred embodiment is comprised of a condensate reservoir disposed between an inlet valve and an outlet valve. The inlet valve controls the intake of pressurized gases and condensate into the condensate reservoir. The inlet side of the inlet valve is connected to the fire sprinkler system and the outlet side of the inlet valve discharges condensate to the condensate reservoir. The outlet valve regulates discharge of condensate that has accumulated in the condensate reservoir. Each valve is power-actuated by a suitable actuator such as a solenoid or the like. In a preferred embodiment, the inlet and outlet valves are attached to an inlet solenoid and an outlet solenoid, respectively. The solenoids open and close the valves at the direction of a programmable controller.
The programmable controller is used to coordinate the opening and closing of the inlet and outlet valves based upon criteria that has been previously entered by a user, such as a building engineer or operator, or by a manufacturing entity. The programmable controller initiates the opening or closing of the inlet or outlet valve by signaling the actuator corresponding to the valve desired to be operated. Thereafter, the actuator either opens or closes the valve.
In one method of operation, the inlet valve is in an open position and the outlet valve is in a closed position while the system is inactive. This position allows the condensate reservoir to collect condensate as condensation forms in the sprinkler system. Once the programmable controller determines that the accumulated condensate should be removed from the system based upon previously determined parameters, the controller signals the inlet actuator to close the inlet valve. With the inlet valve closed, the controller signals the outlet actuator to open the outlet valve. After a predetermined time period, sufficient in length to allow the accumulated condensate to drain from the reservoir, the controller signals the outlet actuator to close the outlet valve. Thereafter, the controller signals the inlet actuator to open the inlet valve. The inlet valve remains open during the period of inactivity until the programmable controller begins the cycle once again.
In another method of operation, the inlet and outlet valves are in closed positions while the system is inactive. As a result, the programmable controller must first open the inlet valve for a specified time period to allow the condensate to drain in to the reservoir for removal. The remaining steps of the process remain unchanged from those set forth above, except that the inlet valve does not remain open during the period of inactivity.
In yet another method of operation, the inlet is closed and the outlet valve is open while the system is inactive. The programmable controller must first close the outlet valve. The inlet valve is then opened to allow the condensate from the system to drain into the condensate reservoir. The remaining steps of this embodiment are set forth in the first method described above. At the conclusion of draining the condensate, the outlet valve remains open.
Currently, there exists no device which solves the problems set forth below. Specifically, there exists a need for automatically draining a sprinkler system used for fire protection in order to prevent exposure of the sprinkler system to mechanical damage caused by freezing water while preventing the release of pressurized gas contained within the sprinkler system. Further, it is desired that operation of the condensate drain system not require on-site personnel to manually drain condensation from the system on a regular basis. Additionally, the automatic control contained within the device must possess the capability of being programmed to drain the system at any interval. Finally, there exists a need to reduce the operating costs associated with manually draining a dry-type fire protection sprinkler system.
The instant invention solves the problems set forth above with a condensate reservoir for collecting condensation from a sprinkler system, an inlet valve connected to the sprinkler system and the condensate reservoir which prevents the discharge of a pressurized gas from the sprinkler system, an outlet valve controlling release of condensate from the condensate reservoir, an inlet solenoid for opening and closing the inlet valve, an outlet solenoid for opening and closing the outlet valve, and a programmable controller having the capability of controlling and operating at least one of the valves.