FR2985751A1 - Snow removal device for use on roof of e.g. industrial building, has programmable logic controller controlling opening of valves, starting of pump and sending of liquid in vacuum circuit in direction of nozzles through solenoid valves - Google Patents

Abstract

The device has spray nozzles (B) for spraying exothermic liquid circulating inside a distribution system mounted on a skid by using valves controlled by a programmable logic controller, where the system is extended from a storage tank to the nozzles. A sensor (D) detects height of snow and sends information to the controller located in a control cabinet. The controller controls opening of the valves, starting of a supply pump and sending of liquid in vacuum circuit in the direction of the nozzles through solenoid valves (E). Pipes transport the exothermic liquid.

Description

The invention relates to an automatic device for melting snow on the roofs of industrial or private buildings without human intervention. This invention is intended to protect the frames of buildings from overweight due to snowfall.

As roofing slopes are becoming weaker for single-family houses and almost non-existent (of the order of a few degrees) for industrial or commercial buildings (hypermarket type), snow can not escape naturally by sliding on the roofs. The risk of accumulation can generate a fatal overload for the frame.

The frames of some buildings can not withstand exceptional amounts of snow or a significant amount of snow on the roof. Construction standards can not account for exceptional amounts of snow. The large areas of some buildings (5000 to 10000m2) are particularly vulnerable to the weight of the snow.

Fifty centimeters of fresh snow weighs 50kg / m2. Current snow removal techniques are all man-assisted. Two methods are used, the first is to spread exothermic granules via a nacelle or directly by mounting on the roofs with the product in bags.

This product is spread on the roof manually with shovels. The second most traditional method is cleaning by man using snow shovels. These men ride on the roofs with harnesses and clear the snow by walking on it. The weight of men on a roof weakened by snow becomes a danger to their safety and the risk of collapse of the roof increases. These two techniques require a lot of organization and manpower available at a time when travel and supply on the roads are often difficult. Another not insignificant point is the amount of snow to be cleaned on buildings of more than 5000m2. Interventions are often carried out during working hours, which is often incompatible with snowfall that is random during the day or at night. The automatic snow removal device consists in spraying an exothermic liquid on the snow.

This liquid has the characteristics of melting snow. It is also used to snow plow airplanes. Diffusers or nozzles are positioned and fixed on the roof of the building.

Diffusers or nozzles are positioned and fixed on the roof of the building. These diffusers are powered by a hose. A "skid" on the ground equipped with a pump and a tank makes it possible to feed the nozzles on the roof with exothermic products via hoses.

A roof-mounted snow detector controls the start-up of the system to prevent too much snow accumulation on the roof. Spraying is done from a certain amount of snow depending on the capacity of the structures to support a greater or lesser load. The detector sends information to a control box.

The cabinet starts the pump and controls the opening of the valves. The exothermic liquid is sent to rotating "lawn sprinklers" mounted on the roof. These diffusers are distributed so as to cover the largest possible area. The rotation of the nozzles ensures a good distribution of the exothermic liquid.

Broadcasters are divided into groups. The groups are successively supplied with fluid through solenoid valves and a delay. This system reduces the capacity of the pump. The pump is calculated according to the roof height of the building and the number of diffusers to be fed at the same time.

After diffusion of the liquid, the snow melts and evacuates via the gutters. The level of snow falls on the roof and the load on the frame becomes normal again. All the elements of Figure (1) is connected on a skid. A skid is a set of apparatus mounted on a chassis. This process allows factory assembly and facilitates transportation.

Figure (2) symbolizes the different devices or elements necessary for the operation of snow removal. Figure 3 shows the positioning of the nozzles on a building roof. Each nozzle can cover a certain area depending on the pressure and flow rate it is subjected to.

The entire installation is divided into two parts: a ground container and a distribution network on the roof of the building to be cleared of snow. The ground container that centralizes the equipment includes: A general box: power supply and control. An automaton: It regulates the diffusion times of the product towards the nozzles.

An exothermic liquid tank: This tank has a capacity proportional to the need of the site. A pump: whose capacity depends on the height of the building.

The roof of the building is equipped with: A set of nozzles or diffusers: These nozzles are divided into groups and fed by a hose. This hose is equipped at the inlet of a solenoid valve that will open and close depending on the amount of fluid to be diffused.

In normal period, the circuit or fluid supply network is empty. The advantage of an empty circuit is to conserve the calories of the exothermic liquid. A second important point, solenoid valves and nozzles should not be trapped in the freeze. The product remains in its tank, which allows it to keep a positive temperature and keep its exothermic power intact.

A circuit without product avoids the evaporation of the liquid by the nozzles in the summer. In the case where the nozzles are taken by a gel due to ice or snow, the product kept at an ideal temperature can defrost the nozzles during use. Industrial applications are numerous.

All the roofs of factories, but also the buildings receiving large public such as schools, indoor stadiums, supermarkets. The risk of a hypermarket collapsing under the weight of snow is not to be neglected and the financial losses linked to a forced closure or a trial should encourage the contractors to secure their infrastructure.

Watering a roof of a building or house saturated by snow with an exothermic liquid to melt it. The preservation of this liquid at a positive temperature improves its essential heating properties when used in very cold rooftops.

The timing of watering broken down into a group of nozzles (2) to keep the flow and pressure adequate, so its price. This timing is achieved using a PLC and a network of solenoid valves. The arrangement of the staggered nozzles (3) on a building optimizes the number of nozzles needed to cover the entire surface of the roof.

The lines are not supplied with exothermic liquid before start-up. The network is empty. This method keeps the liquid all these thermal capacities since it is stored in a positive temperature tank. It can also thaw a nozzle in the snow due to the heat of the liquid and the pressure of the pump.

The realization of the distribution system on the ground mounted on a "skid". The implementation of the installation on a "skid" reduces manufacturing costs but also facilitates transport and removal. It can thus be implemented at the customer's premises or leave outside if it was designed in a container.

The use of this method with water to cool solar panels or photovoltaic during periods of high temperatures. Nomenclature figure 1 and 2 Designation Control and power cabinet Nozzles or diffusers Fluid tank Snow level sensor Solenoid valve Connection hose Electrical heating General power supply Supply pump Thermostat Rep A B C D E F G H P T

Claims (6)

CLAIMS1) Snow removal device for melting snow on the roofs. This device is characterized by the presence of nozzles (Figure 3), an exothermic liquid circulating inside a distribution circuit (Figure 1) from a storage tank to the nozzles using valves controlled by a PLC. The snow depth detection is performed by a sensor (B) which sends the information to a PLC located in the control cabinet (A). This opens the valves of the circuit, starts the pump (P) and sends the liquid in the empty circuit to the nozzles (B) via the solenoid valves (E). 2) Device according to claim 1 characterized in that the pipes carrying the exothermic product are not supplied with liquid before startup. The network is empty. The liquid is stored in a positive temperature tank located on the ground in a "skid". 3) Device according to claim 1 characterized in that the timing of the watering is decomposed in a group of nozzles Figure 2 to keep the flow and the appropriate pressure, so its price. This timing is achieved using a PLC and a network of solenoid valves. 4) Device according to claim 3 characterized in that the arrangement of the groups of nozzles is staggered (Figure 3) on a building. 5) Device according to claim 2 characterized in that the realization of the distribution system on the ground is mounted on a "skid". 6) Device according to claim 3 characterized in that the use of this timing method with water to cool solar panels or photovoltaic.