JPH035421Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" The present invention relates to ice blasting equipment, and in particular,
The present invention relates to an ice blasting device that dehumidifies an ice grain storage tank and the like before starting or stopping blasting.

``Prior art and its problems'' One method of decontaminating equipment used in nuclear power generation facilities is the so-called method of injecting ice particles onto the object to be decontaminated to peel off contaminants from its surface. Ice blasting has been carried out.

Conventionally, equipment for performing such ice blast processing temporarily stores ice particles such as dry ice produced by a granulator in a tank.
While being discharged from the tank, it is conveyed to a blast nozzle by a carrier fluid such as compressed air and sprayed.

However, with such ice blasting equipment, a sudden temperature drop inside the tank at the start of the blasting process tends to cause the moisture in the air to freeze and stick to the inner walls of the tank. In addition, even when the blasting process is temporarily stopped, the air remaining in the tank causes a freezing phenomenon, and this freezing blocks the flow path for ice particles, which hinders the blasting process. Easy to occur.

"Purpose of the present invention and means for achieving the same" The purpose of the present invention is to provide an ice blasting device that can increase treatment efficiency by preventing freezing inside the tank when starting and stopping the blasting process. The feature is that a cold gas supply system is provided that supplies cold gas for dehumidification to the tank when the supply of carrier fluid by the fluid supply system is cut off. In addition to pre-cooling, the air inside the tank is expelled to create a deaerated atmosphere, thereby dehumidifying the tank.

"Embodiment" Hereinafter, an embodiment of the ice blasting device of the present invention will be described based on the drawings.

In the figure, code 1 is the ice grain supply system, codes 2A and 2B
are a pair of tanks that primarily store ice grains supplied from the ice grain supply system 1; symbol 3 is a pair of tanks 2A and 2B;
A carrier fluid supply system 4, which supplies a carrier fluid such as compressed air for conveying the ice particles inside, is an ice particle conveying system, 6, which conveys a mixed fluid of ice particles and carrier fluid to the blast nozzle 5. is a cold gas supply system for sending cold gas into the tanks 2A, 2B, etc.

To explain these in detail, the ice grain supply system 1 includes a granulator 7 connected with a liquid carbon dioxide supply source 8 and a water supply source 9, and produces dry ice by mixing these carbon dioxide and water. It has started producing ice grains. The granulator 7 and both tanks 2A,
A three-way switching valve or the like is supplied to a branch part of the ice grain supply pipe 10 disposed between the tank 2B and the ice grain supply pipe 10, which selectively opens the flow path to both tanks 2A and 2B and blocks other flow paths. A switching means 11 is provided. The granulator 7 is connected with a duct 12 for discharging carbon dioxide gas generated when producing ice grains, and is provided with a valve 13 for opening and closing the flow path.

In addition, each of the tanks 2A and 2B is provided with an ice particle discharge pipe 14A and 14B, respectively, below the ice particle discharge pipe 14A and 14B, and a certain amount of ice particles in the tank 2A and 2B are dropped into the ice particle discharge pipe 14A and 14B. A rotary feeder 15 is disposed, and below the rotary feeder 15, merging portions 16A and 16B with the carrier fluid supply system 3 are provided, respectively, and further below the merging portions 16A and 16B are provided for drainage. A valve 17 is provided in series. Each of the rotary feeders 15 is configured such that the supply switching means 11 blocks the flow path of the ice grain discharge pipe of the tank in which the flow path of the ice grain supply pipe 10 is in an open state, and the flow of the ice grain discharge pipe of the other tank is controlled. The drive is controlled so as to open the road.

Further, the carrier fluid supply system 3 is branched at a downstream position of the main valve 18, and the respective merging portions 16A,
A pair of carrier fluid supply pipes 19A and 19B are arranged to respectively supply carrier fluid to the carrier fluid supply pipes 19A and 19B, and the downstream positions of valves 20 and 21 for opening and closing flow paths in the carrier fluid supply pipes 19A and 19B are further branched. Pressurized lines 22A and 22B are configured, which are connected to each tank 2A and 2B, respectively, and which supply part of the carrier fluid into the tanks 2A and 2B to promote release of ice grains by the rotary feeder 15, Valves 23 to 26 are also provided in the pressure lines 22A and 22B.

The ice grain conveyance system 4 includes each confluence section 16A, 16B.
and the blast nozzle 5 are connected via a guide 27 such as a three-way switching valve, and the guide 27
is controlled so that the rotary feeder 15 selectively communicates between the operating ice particle discharge pipe and the blast nozzle 5. Note that a valve 28 is provided at a position downstream of the guide 27 of the ice particle transport system 4.

On the other hand, the cold gas supply system 6 supplies cold gas from a cold gas supply source 29 such as nitrogen gas or the granulator 7 to each confluence section through the carrier fluid supply pipes 19A, 19B and pressurizing lines 22A, 22B. 1
The cold gas supply source 29 is supplied to the cold gas supply source 29 and the tanks 2A and 2B by opening and closing the valves 30 and 31 provided at the outlet of the cold gas supply source 29 and the granulator 7. Either cold gas such as nitrogen gas or cold gas such as carbon dioxide gas generated in the granulator 7 can be used.

Note that the reference numeral 32 in the figure is a so-called waste valve.

The ice blasting device configured in this way is
The ice grains produced by the granulator 7 can be temporarily stored in tanks 2A and 2B, and transported to the blast nozzle 5 by the carrier fluid supplied from the carrier fluid supply system 3 for blasting. However, before the blasting process starts or while the blasting process is stopped, that is, when the supply of carrier fluid from the carrier fluid supply system 3 is cut off, cold gas is supplied from the cold gas supply system 6 into the tanks 2A, 2B, etc. By pumping air into the tank 2 and expelling the air therein,
It is possible to pre-cool and dehumidify A, 2B, etc.

That is, in order to pre-cool and dehumidify the insides of the tanks 2A, 2B, etc. before starting the blasting process, the valve 28 of the ice grain conveying system 4 is closed, and the valve 28 of the cold gas supply source 29 in the cold gas supply system 6 is closed. 3
0, each valve 23-26 of pressurization line 22A, 22B
By opening the drain valve 17 and supplying cold gas to the tanks 2A, 2B and the respective merging sections 16A, 16B and discharging it to the drain system via the drain valve 17, as shown by arrow A, It is possible to pre-cool the tanks 2A, 2B, etc., and to expel the air therein to dehumidify them.

In addition, in order to perform the blasting process, the valve 30 and the drain valve 17 are closed, and the ice particles produced by the granulator 7 are first placed in one of the tanks 2A and 2B.
For example, it is supplied to the tank 2A to fill the tank 2A. Next, the supply switching means 11 is switched to supply ice grains to the tank 2B as shown by the arrow B, while the valves 25 and 26 are closed to switch the main valve 18, valve 20 of the carrier fluid supply system 3 and the ice grain transport system. At the same time, the guide 27 is communicated with the ice particle discharge pipe 14A of the tank 2A, and the ice particle discharge pipe 14 is opened.
By putting the rotary feeder 15 A into operation, the ice particles are transferred to the ice particle conveying system 4 as shown by the arrow C.
It is conveyed to the blast nozzle 5 via the blast nozzle 5 and sprayed. When the tank 2A becomes empty, the supply switching means 11 is switched to supply ice particles to the tank 2A, and at the same time, the operation of both rotary feeders 15, the direction of the guide 27, the valves 20, 21, and the valves 23 to 26 are controlled. By switching between opening and closing, ice particles are conveyed from the tank 2B to the blast nozzle 5 and sprayed. Thereafter, in the same manner, the blasting process is performed continuously while alternately switching the supply and conveyance of ice grains between the tanks 2A and 2B.

On the other hand, when the blasting process is temporarily stopped, the operation of the granulator 7 is continued, and the carbon dioxide gas generated by the granulator 7 is used to dehumidify the tanks 2A, 2B, etc. That is, both rotary feeders 1
At the same time, the transport fluid supply system 3 is stopped.
By shutting off the supply of conveying fluid by the ice particle conveying system 4, closing the valve 28 of the ice particle conveying system 4, and opening the drain valve 17 and the valve 31 of the cold gas supply system 6, as shown by arrow D, the carbonic acid gas tank 2
A, 2B and each merging section 16A, 16B and discharged to a drain system to create a deaerated atmosphere in the tanks 2A, 2B, etc.

In addition, in the above embodiment, the cold gas was discharged to the drain system through the drain valve 17.
It may also be discharged from the blast nozzle 5.

"Effects of the Invention" As explained above, according to the ice blasting device of the present invention, a tank for temporarily storing ice particles includes a carrier fluid supply system for transporting ice particles, and a carrier fluid supply system for supplying a carrier fluid. Since the cold gas supply system is connected to the cold gas supply system that supplies cold gas for dehumidification when the supply is cut off, it is possible to supply cold gas from the cold gas supply system to the tank before starting or during the blasting process, etc. By expelling the air, it is possible to perform pre-cooling and dehumidification, and prevent freezing inside the tank when starting or stopping the blasting process. Therefore, the circulation of ice particles is smoothed and processing efficiency is improved. It has the effect of increasing

[Brief explanation of drawings]

The drawing is a piping system diagram showing one embodiment of the ice blasting device of the present invention. 1... Ice particle supply system, 2A, 2B... Tank, 3
...Carrier fluid supply system, 4...Ice particle transport system, 5...
Blast nozzle, 6... Cold gas supply system, 7...
Granulator, 10... Ice grain supply pipe, 11... Supply switching means, 12... Duct, 13... Valve, 14A, 1
4B...Ice particle discharge pipe, 15...Rotary feeder, 16A, 16B...Confluence section, 17...Drain valve, 19A, 19B...Carrier fluid supply pipe, 2
0, 21...Valve, 22A, 22B...Pressure line, 23-26...Valve, 27...Guide, 28...
...Valve, 29... Cold gas supply source, 30, 31...
valve.

Claims (1)

[Scope of utility model registration request] A carrier fluid supply system for conveying ice particles by a carrier fluid to a tank for temporarily storing ice particles supplied from the ice particle supply system and injecting them from a blast nozzle; and a carrier fluid supply system for supplying the carrier fluid. An ice blasting device that is connected to a cold gas supply system that supplies cold gas for dehumidification when in a shut-off state.