In actual kitchen rescue planning and construction, large or super large hoods are encountered. This article specifically introduces some issues that kitchen rescue systems must pay attention to in the planning and construction of such hoods. This article only considers mechanical Thermal sensing and mechanical launch system.
Hoods that generally exceed 10 meters and are shorter than 15 meters
Generally more than 15 meters of hood
In the planning of the kitchen rescue system, once a hood larger than 10 meters is encountered, it should be very careful. In addition to the requirements in the planning area, the planning characteristics of the product and the feasibility of on-site construction must be considered.
Considerations for planning
In the current exploration of several leading brands in the market, mechanical temperature-sensing explorers are used. Whether it is a backup pressure or a storage pressure, their operating principle is based on the added elasticity after the fusible fusing. Potential energy (tension spring energy storage) pulls the steel wire rope, so that the firing pin above the second energy storage element (nitrogen cylinder) moves downward to pierce the nitrogen cylinder seal, and completes the function of driving the gas out.
Its role is to release the pressure-prepared medicament to a pre-planned danger zone or to open the pressure-reserved bottle head valve. Because of the certain ductility of wire ropes, there are certain restrictions on the number of prospectors. If the maximum value is exceeded, a corresponding method is adopted, which we call long-distance control.
Because of the constraints of the capacity and pressure of the driving nitrogen bottle or pressure storage bottle, the flow and interval of the system's release pipeline network are also subject to constraints. When the constraints imposed by the product are exceeded, long-distance control is also required.
Considerations required during construction
In the general system, the flow and driving interval of the pharmacy release pipe network have the highest constraints. If it exceeds the limit, it must be controlled by long distance. In general planning, the long-distance controlled release box and the medicine tank are placed on the same side. From a planning perspective, this method is understandable, but this method is selected after strict calculations, or the limit conditions may be exceeded.
Practice has proved that the method of double-sided placement is more effective, that is, the long-distance control box and the medicine tank are placed on both sides of the maintenance hood, and then the two long-distance start boxes are connected through a 1 / 4-inch pipe, which is illustrated by an example below.
Three examples are currently prevailing in the rescue of Ansu Kitchen. Each main box can be connected to 15 mechanical temperature-sensing explorers, and one release box can take two auxiliary release boxes, as shown in Figure 1:
In other words, the long-distance control system should be used when more than 15 pharmaceutical tanks or 15 prospectors are used.
☑ Long-distance control: Long-distance control can connect up to 5 medicine tanks, and each long-distance launch control box can carry 15 explorers, as shown in Figure 2. Thirty, five vice boxes. In other words, a maximum of five piranha 13 canisters can be brought.
A schematic diagram of the principle of long-distance launch. If planning and construction according to this diagram may present a principle fault, please pay attention to Table 1, which gives the farthest interval that can be driven by different types of pharmaceutical tanks and the equivalent interval of pipe fittings. .
If the construction of the long-distance control box is placed on the same side as shown in Figure 2, the system planning may fail due to the release of the equivalent length of the pipe network. Therefore, the equivalent length calculation for hoods exceeding 10 meters must be carried out severely. If the calculation of the equivalent length exceeds the limit, the following method should be adopted.
☑ Solution: Put the long-distance release box on both sides of the hood, and bring two or three medicine tanks on each side as needed, but the sum of the two sides cannot exceed five, and then pass the two long-distance release boxes through a 1/4 inch hose Or hard pipe connection constitutes a long-distance control system, see Figure 3.
If the site has the conditions, it can be considered from planning and construction induction. Even if the equivalent length on one side does not exceed the limit, this method can be used. The advantages are simple construction and material cost savings.
Chongqing kitchen fire extinguishing equipment ★ Note: There are two connection methods for the Ansu kitchen rescue system release pipe network:
Connected systems and branch systems are shown in Figure 4.
Continuous system: The system between the first nozzle and the medicine tank does not include the horn tee.
Branch system: The release pipe network includes a horn tee, which establishes the connection between the medicine tank and the sprinkler.
The planning and construction of the large-scale fume hood kitchen rescue system should be summarized and considered according to the site conditions. The intention is to reach the rescue intention and make the construction simple, so that the function of the system reaches the extreme.