GB2448177A

GB2448177A - Thermally insulated atmospheric expansion tank

Info

Publication number: GB2448177A
Application number: GB0706671A
Authority: GB
Inventors: Mohammad Saeid Mehrafza; Mohammad Reza Mehrafza
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-04-05
Filing date: 2007-04-05
Publication date: 2008-10-08
Also published as: GB0706671D0

Abstract

An atmospheric expansion tank comprises two main sections consisting of a body and a lid. In each section, the space between an inner layer 3, 6 and an outer layer 1, 4 is uniformly injected with polyurethane foam 2, 5 so as to provide a uniform thermal resistance. A tight fit is provided between the tank body and the lid. The tank is designed to provide sufficient uniform insulation against heat transfer from the inside to the outside of the tank so that, in use, the insulated tank saves energy and consequently reduces fuel costs. The insulation thickness is calculated according to the temperature difference between a central heating system set point and the ambient temperature. Preferably, the tank is designed to keep a fluid temperature constant whilst maintaining atmospheric pressure by purging a fluid, such as water, through an overflow valve.

Description

Atmospheric Expansion Tank (Open)

Invention Description

Technical Field

This invention, which relates to one of the components of hot water central heating system, operates on the principles of the fluid volume fluctuation in the heating cycle.

Relevant Prior Art

These tanks are employed to house the expanded fluid during the heating cycle; hence it prevents the explosion of boiler as well as damages which are caused by the created vacuum during the cooling cycle.

In the past, less attention has been paid to the quality and development of this kind of component because of the simplicity of the structure and cheap fuels.

Assessment of Prior Art

Nowadays, there is a variety of cylindrical or cubical atmospheric expansion tanks being manufactured according to the consumers' demands. These tanks not only have a short lifespan due to lack of the insulation and exposure to the natural erosive elements such as the sunlight, rain, wind, etc. but they also cause considerable heat loss and environmental pollution.

These widely used tanks that are installed at least 3 meters above the last radiator, mostly on the roof. They are constantly exposed to the wind, snow and rain and lose the considerable amount of heat due to lack of the insulation, choice of the poor materials and the workmanship. This loss of heat goes against the energy saving measures which are taken to tackle the contemporary energy crisis.

Disclosure

Assessing the current expansion tanks shows the deficiency in seaming of the lid and body of such tanks is the source of a huge amount of energy loss through vaporization of the fluid and consequently reduced efficiency of the system. Reduction in efficiency is compensated by overworking of the system and subsequently results in rapid depreciation, as well as an increase in and electricity and fuel consumption.

This invention aims to create a completely insulated expansion and contraction improved tank, which increases the efficiency by saving the energy of a central heating system in the atmospheric pressure.

These tanks are designed in such a way that while keeping the fluid temperature constant, they maintain the atmospheric pressure in the closed system by purging water through overflow valve.

Considering the place of the installation of these tanks and the effects of the natural elements such as temperature fluctuations, wind, snow, rain, etc. upon them, there are some considerable advantages in manufacturing these types of tanks compared with the current tanks on the market under the same application and the climatic conditions.

Advantageous Effects According to the calculations and tests which were performed on the prototype of this tank, this invention has many advantages: -Fuel consumption decreases up to 1000 cubic meters per year (considering the climatic conditions) for each building equipped with hot water central heating system.

-Green house gases decrease and the entropy of the atmosphere can be controlled.

-Reduction in electricity consumption -Protecting natural resources.

-Reducing depreciation of the system.

-Reducing household expenses.

-Creating a uniform temperature throughout the system. (Except radiators) -Uniform distribution of constant heat throughout the building.

-It pays off the cost of tanks by savings on the fuel in a short period of time.

One of the other advantages of this invention is an easy installation and application in the system. There is neither need for modification nor specially trained installers.

Example

This invention is elaborated further using following figures: Fig. 1 Axial cross section of the body section which shows the body and bottom of this tank is comprised of three one-piece concentric inner, middle and outer layers that are fused to each other.

Fig.2 Axial cross section of the lid, which is also made of the same three concentric layers.

Fig3. Half scale isometric cross section out of the lid of the improved open expansion tank.

The space created between Rl-R2 and Hl-H2 (Fig.!) has been injected with polyurethane foam with appropriate density (Fig. 4) in order to have a good thermal resistance. During manufacturing process, foam is injected in this space without leaving any hollow space Lbulb) inside the foam to avoid thermal bridge between two layers. Using an example of this tank with given dimensions of different layers. Fig. 1 and Fig. 2 helps to better understand this invention.

Rl= 231 mm, R2= 261 mm, R3= RI, hl=480mm, h2=450mm Obviously, in order to achieve improved results, the thickness of polyurethane varies depending on tank capacity and climatic condition.

Claims

Claims 1. Atmospheric expansion tank (open) is comprised of two main

sections of a body and a lid. In both sections, the space between the inner layer with radius of Ri and the outer layer with radius of R2 (Fig. 1) has been uniformly injected with appropriate density of polyurethane foam to cause uniform thermal resistance. The entire unit has a design that, along with its tight fit between the body and the lid, creates a uniform and sufficient insulation against heat transfer.
2. In the cylindrical shaped body section (Fig. 1), the difference between radii of the smaller inner layer (RI) and larger outer layer (R2) as well as the difference between the heights of smaller inner layer and larger outer one which is filled with polyurethane (thickness of the tanks) is calculated and determined according to the difference between the temperature of setting of the central heating system and ambient temperature of where they are used.
3. Thickness of polyurethane in the lid (Fig. 2) is determined by the space between the inner and outer layers and diameter of the outer layer and its rim is determined according to the diameter and shape of the outer layer of the body for a better tightness and seal.
4. The dimensions of the installed expansion tank (Fig.!, 2) as claimed in claims 1,2: Rl= 231 mm, R2= 261 mm, R3=Rl, hI= 480 mm, h2450mm
5. In installed expansion tank as claimed in claims 1 to 3, dimensions and measurements of each one ensures that no heat is transferred from inside to the outside.