PLANT AND METHOD FOR MELTING AND CLEANING OF SNOW AND ICE

Abstract

Plant for melting and cleaning of snow and ice, distinguished in that the plant comprises a means for melting using enthalpy of a water source in order to melt snow and ice, and a means for cleaning for cleaning out the pollution from the water phase that contains the melted snow and ice. Method for melting and cleaning of snow and ice, using the plant according to the invention.

Claims

1. A plant for melting and cleaning of snow and ice, the plant comprising: means for melting using enthalpy of a water source in order to melt snow and ice; and means for cleaning out pollution from a water phase that contains the melted snow and ice.

2. The plant according to claim 1, wherein the means for melting is without heaters for melting by burning fuel or consuming electricity as the water source is in substance or merely a natural low temperature source of water that is not heated.

3. The plant according to claim 1, wherein the plant comprises a means for crushing of ice.

4. The plant according to claim 3, wherein upstream of the means for crushing of ice, a means for sorting out larger objects from polluted snow and ice is arranged.

5. The plant according to claim 1, wherein the plant comprises a means for supplying hot water to polluted snow and ice, upstream of or into the means for melting.

6. A method for melting and cleaning of snow and ice using the plant according to claim 1, wherein the method comprises: supplying polluted snow and ice to the plant; melting the polluted snow and ice using the enthalpy of the water source; and cleaning the water phase including the melted snow and ice.

7. The method according to claim 6, wherein the melting takes place without burning fuel or using electricity for melting, or drilling wells for geothermal heat.

Description

FIGURES

[0011] An embodiment of a plant according to the invention is illustrated in FIGS. 1-4, of which

[0012] FIG. 1 shows a plan drawing of a plant according to the invention,

[0013] FIG. 2 shows a process line AA along the main process center line, along the line AA in FIG. 1,

[0014] FIG. 3 shows features at the outlet from the lamellar separator of FIG. 1, as a filter cloth is arranged around the outlet to avoid clogging and to prolong the service life of the downstream sand filter, and

[0015] FIG. 4 shows the plant illustrated in FIG. 1, but three dimensional and viewed obliquely.

[0016] FIG. 5 is a plan of a plant of the invention.

DETAILED DESCRIPTION

[0017] We assume that the figures in general are self-explanatory for persons skilled in the art. Calculations have been made for a centrally located plant for the city of Oslo. The reduction as a result of reduced traffic alone, ie without the effect of the treatment plant included, is estimated to be 2.6-2.9 tons of NOx, 1.5 tons of CO, 0.3 tons of VOC, 0.1 tons of particulates and 340-450 tons of CO.sub.2. If the plant is implemented on an existing barge or placed on land, the savings in emissions of SO.sub.2 from the transport 0.15 tonnes.

[0018] The reduction in emissions when taking into account that no fuel must be burned or no electric power used in order to melt the snow and ice, and adding the emissions cleaned out from the melted snow and is, is many times larger than the figures mentioned above. The only essential feature requiring power is a pump or flow device used to pump for example seawater at 4 C. into a plant of the invention, taking out for example 3.5 C. of heat energy, discharging water at 0.5 C. after cleaning the mixture of seawater and melted snow and ice, assuming the heat exchange is an open mixing type.

[0019] For a city like Oslo, the melting of snow and ice will typically require an enthalpy of 24.3 MW, for an assumed peak load of melting 500 m.sup.3/hour snow with some ice per hour, consuming 350 kJ/kg for melting. Taking out 3.5 C. from the water of a low temperature water source for melting, will require a pump delivering 5800 m.sup.3/hour. Pumping up seawater from below 25 m depth, and lifting the water 4 m from a pump located at sea level, will require a pump using about 0.082 MW power. Adding power for possible and preferable crushing and agitation, the total plant power requirement will be about 0.1 MW. Using the cooling water of the pump for melting and to avoid clogging, will reduce the water flow rate requirement. Prior art technology using heaters run by burning fuel or consuming electricity, will require 25 MW compared to 0.1 MW for operation. Prior art plants will thereby burn 2640 liter diesel per hour or 1884 kg propane per hour. A prior art plant operating on diesel will emit 7920 kg CO.sub.2 per hour for melting snow and ice, compared to 0 for a plant according to the invention. Additionally, the plant of the invention provides effective cleaning and can be located at a site for minimum transport requirement.

[0020] FIG. 2 shows a process line 6 along the main process center line. FIG. 3 shows features at the outlet 12 from the lamellar separator 5 of FIG. 1, as a filter cloth 11 is arranged around the outlet 12 to avoid clogging and to prolong the service life of the downstream sand filter 4.

[0021] Essential features of the invention are to use in substance natural low temperature water in heat exchange for melting, in order to reduce the power requirement for melting dramatically, the melting is required for effective subsequent cleaning as snow and ice per se is difficult to clean effectively, and to including the means for cleaning in order to solve the pollution problem as discussed in the introduction of the description. The means for melting mainly consists of an enthalpy chamber for heat exchange with a natural low temperature water source for melting snow and ice.