CZ12574U1 - Apparatus for thermal disinfection of warm water - Google Patents

Description

This technical solution concerns thermal disinfection of hot water. Thermal disinfection is an increase in the temperature of the water to the point where Legionella pneumophilia bacteria die. For a reliable thermal disinfection process, the elevated temperature must be maintained for a certain period of time. Thermal disinfection of Legionella pneumophilia bacteria is carried out in buildings where people with reduced immunity can come into contact with hot water, these are mainly medical facilities. The thermal disinfection unit can be used wherever we want to ensure that Legionella pneumophilia bacteria are not present in hot water systems such as hotels, hostels, sports facilities and residential buildings.

The heat source for thermal disinfection may be hot water, hot water or steam, provided that the minimum temperature of the heating medium is always above 73 ° C.

BACKGROUND OF THE INVENTION

Given the current knowledge of the properties of Legionella pneumophilia, it is known that Legionella bacteria are destroyed at temperatures above 55 ° C. At this temperature, the destruction time is 240 min.

As the temperature rises, the time required to kill bacteria is reduced, see table:

° C 60-120 min ° C 70-90 min ° C 8-10 min ° C 4-6 min.

The temperature sensitivity of the bacteria is used to design devices that disinfect hot water from Legionella pneumophilia.

Equipment for the protection of hot water systems can be divided into two groups:

1) systems with programmed one-time overheating approx. 1 x per week.

2) systems where thermal disinfection is carried out continuously; all cold water entering the hot water system is treated.

The described device operates on the principle of group 2.

The hot water is heated to a disinfection temperature (70 ° C) and remains at that temperature for a sufficiently long time in the so-called reaction tank.

All cold water passes through thermal disinfection. At the same time, the cold water serves to cool the heated hot water exiting the disinfection tank (70 ° C) to a temperature of 55 ° C; temperature, which is required at individual sampling points.

For the correct functioning of the thermal disinfection unit, it is crucial to set the parameters of the device so that all water passing through the disinfection tank has a temperature of 70 ° C and stays at this temperature for at least 10 minutes.

The volume of the disinfection tank and the character of its installation determines the flow rate when the water flows through the tank in a specified time (minimum 10 min requirement).

By keeping warm water at a high temperature (70 ° C), the intensity of precipitation of dissolved minerals in cold water is also high. The formation of incrustations greatly affects the flow properties of the heat exchanger in the disinfection tank circuit.

In the present technical solution, the amount of disinfection flow is achieved by a pump and manually adjustable balancing valve. However, this method does not take into account a partial change in flow rate due to the operational clogging of both the heat exchangers and the individual fittings in the system.

-1 CZ 12574 Ul

This can result in the technical degradation of the entire equipment and the inability of thermal disinfection while maintaining sufficient disinfection performance.

Another drawback appears to be the use of a standard type of storage tank as a disinfection tank. After the superheated hot water enters the standard storage tank, the newly superheated hot water is mixed with the water remaining in the reaction tank and thus the required residence time of the superheated hot water at the disinfection temperature cannot be guaranteed.

The essence of the technical solution

Equipment for thermal disinfection of hot water, according to the proposed solution, in which a pump, balancing armature, disinfection exchanger, disinfection tank and accumulation tank are installed in the disinfection circuit.

The essence of the solution is that there is a device for determining the flow rate between the connection of the medium to the disinfection circuit and the connection of the accumulation tank to the outlet of the disinfection tank. At the same time, the disinfection tank is equipped with an internal built-in to ensure a uniform flow of medium and the pump in the disinfection circuit is equipped with a speed converter.

The technical solution for flow monitoring is to install a flow rate device and a pump with frequency converter in the water heating circuit to the thermal disinfection temperature. This device detects the flow rate in the disinfection circuit and provides information to a control system that adjusts the speed of the disinfection pump to maintain the desired constant disinfection flow through the device.

In this way, the proposed disinfection parameters of the plant can be guaranteed throughout the operating period.

If the system becomes clogged so that the pump in the full-capacity thermal disinfection circuit is not able to ensure the correct disinfection flow rate, an automatic fault condition is indicated.

This prevents the unit from working, but its disinfection performance is limited and the operator knows no problem with the performance of the unit.

In order to guarantee the flow time of thermally disinfected water, the disinfection tank has special internal fittings which prevent mixing of the newly entering hot water and the water already stored in the tank.

The internal fittings adjust the direction of water flow in the reaction tank so that the flow of water in the tank does not exceed the correct reaction time (10 min).

BRIEF DESCRIPTION OF THE DRAWINGS

The proposed technical solution is evident from the present diagrams, where Fig. 1 shows a known thermal disinfection device and Fig. 2 shows thermal disinfection with flow monitoring and using a disinfection tank with internal fittings, Fig. 3 and Fig. 4 show examples of internal assembly of the tank .

Examples of technical solution

The hot water disinfection device has a pump I, a balancing arm 7, a disinfection exchanger 4, a disinfection tank 5 and a storage tank 10 installed in the disinfection circuit.

Between the connection A of the medium inlet to the disinfection circuit and the connection B of the accumulation tank M to the outlet of the disinfection tank 5 there is a device 2 for determining the flow rate.

The disinfectant container 5 is provided with an internal built-in 6 which ensures a uniform flow of the medium. The internal installation 6 consists of circular sheet metal installations with sectors. Slices are

In this case, the inlet of the medium into the disinfection container 5 is from the side, the solution is shown in Fig. 3.

Alternatively, the interior assembly 6 may be formed of sheet metal circular assemblies with openings. The openings are arranged in such a way that the flow rate of the medium through the inner installation 6 downwards is uniform, i.e. the flow of the medium. in the middle that there are smaller holes, the diameter of which increases towards the housing of the disinfectant container 5.

Pump I in the disinfection circuit is equipped with a speed converter 11, which can be both external and internal.

List of reference numbers: ίο 1 - pump

- flow rate determination device

- control system

- disinfection exchanger

- disinfection tank

6 - internal installation

- balancing armature

- storage tank

- speed converter A, B - connection.

Claims (1)

Device for thermally disinfecting hot water, in which a pump (1), a balancing fitting (7), a disinfection exchanger (4), a disinfection tank (5) and an accumulation tank (10) are installed in the disinfection circuit, characterized in that by connecting (A) the medium to the disinfection circuit and connecting (B) the storage tank (10) to the disinfection outlet 25 of the reservoir (5), there is a device (2) for determining the flow rate and at the same time the disinfection reservoir (5) is equipped with an internal built-in (6) to ensure a uniform flow of medium and pump (1) in the disinfection circuit is equipped with a speed converter (11).